CN114911096A - Display devices, head-up displays, traffic equipment, and light source devices - Google Patents

Abstract

Embodiments of the present disclosure provide a display device, a head-up display, a traffic device, and a light source device. The display device includes a display panel having a display surface and a backside opposite to the display surface; and a backlight located on the backside of the display panel. The backlight source includes an optical waveguide plate, the optical waveguide plate includes a light homogenizing part and an optical waveguide element, the optical waveguide element includes a light emitting surface, and the light homogenizing part and the optical waveguide element are arranged in sequence in a direction perpendicular to the light emitting surface; the backlight source also includes a light source part, The light source part is configured so that the light emitted from the light source is totally reflected in the light homogenizing part many times and then enters the optical waveguide element, and then exits from the light emitting surface of the optical waveguide element. In the display device provided by the present disclosure, by arranging the optical waveguide element and the light homogenizing part, the uniformity of the light before being transmitted to the optical waveguide element can be improved, and the area occupied by the light homogenizing part can also be saved, thereby improving the light output of the backlight source. surface area.

Description

Display devices, head-up displays, traffic equipment, and light source devices

technical field

At least one embodiment of the present disclosure relates to a display device, a head-up display, a traffic device, and a light source device.

Background technique

At present, users have higher and higher requirements for the use of display devices including backlight sources, and more requirements are also put forward for their display effects, portability and other performance. And performance such as portability has a certain degree of impact.

SUMMARY OF THE INVENTION

At least one embodiment of the present disclosure provides a display device, a head-up display, a traffic device, and a light source device.

At least one embodiment of the present disclosure provides a display device including: a display panel having a display surface and a backside opposite to the display surface; and a backlight located on the backside of the display panel. The backlight includes an optical waveguide plate, the optical waveguide plate includes a light homogenizing part and an optical waveguide element, the optical waveguide element includes a light exit surface, and the light homogenization part and the optical waveguide element are perpendicular to the light exit surface. Arranged in sequence in the direction; the backlight further includes a light source part, the light source part is configured so that the light emitted by the light source enters the optical waveguide element after multiple total reflections in the uniform light part, and then emits light from the light The light exit surface of the waveguide element exits.

At least one embodiment of the present disclosure provides a head-up display, comprising: any one of the display devices of the present disclosure; and a reflective imaging portion located on a light-emitting side of the display device and configured to reflect light emitted from the display device to a The viewing area of the head-up display.

At least one embodiment of the present disclosure provides a transportation device including any of the heads-up displays of the present disclosure.

At least one embodiment of the present disclosure provides a light source device, comprising: an optical waveguide plate, wherein the optical waveguide plate includes a light homogenizing part and an optical waveguide element, the optical waveguide element includes a light exit surface, and the light homogenizing part is connected to the light distribution part. The optical waveguide elements are sequentially arranged in a direction perpendicular to the light exit surface; and a light source part, wherein the light source part is configured so that the light emitted by the light source part enters the The optical waveguide element is then emitted from the light exit surface of the optical waveguide element.

For example, in the embodiment of the present disclosure, the number of times of the multiple total reflections is not less than 5 times.

For example, in the embodiment of the present disclosure, the light-diffusing part includes a light-incident end and a light-exiting end, and the light-incoming end and the light-exiting end are arranged along the extending direction of the light-exiting surface; The thickness in the direction of the light exit surface is not greater than the thickness of the optical waveguide elements in the arrangement direction.

For example, in the embodiment of the present disclosure, the refractive index of the uniform light portion is greater than the refractive index of the waveguide medium in the optical waveguide element.

For example, in the embodiment of the present disclosure, the optical waveguide plate is an integrated structure.

For example, in the embodiment of the present disclosure, a gap medium is provided between the optical waveguide element and the light homogenizing part in a direction perpendicular to the light exit surface, and the refractive index of the waveguide medium in the optical waveguide element is the same as the The refractive index of the uniform light portion is all larger than the refractive index of the gap medium.

For example, in the embodiment of the present disclosure, a connecting portion is further provided between the optical waveguide element and the light homogenizing portion, and the connecting portion connects the light incident end of the optical waveguide element and the light exiting portion of the light homogenizing portion. The ends are connected, so that the light of the homogenizing part enters the optical waveguide element through the connecting part.

For example, in the embodiment of the present disclosure, the connection part includes a light adjustment part, and the light adjustment part is configured to destroy the total reflection condition of the total reflection of the propagating light in the light uniformity part, so that the light uniformity part is Light propagating in can enter the optical waveguide element.

For example, in an embodiment of the present disclosure, the connecting portion further includes a reflective surface, and the reflective surface is configured to reflect the light in the uniform light portion into the optical waveguide element.

For example, in the embodiment of the present disclosure, the optical waveguide element includes an optical outcoupling portion, and the optical outcoupling portion includes a plurality of optical outcoupling sub-portions arranged along the extending direction of the light outgoing surface.

For example, in an embodiment of the present disclosure, the optical waveguide element further includes a waveguide medium, the optical coupling part includes a transflective element array located in the waveguide medium, and each transflective element of the transflective element array is is configured to reflect a portion of the light propagating to the transflective element out of the optical waveguide element and transmit another portion of the light.

For example, in the embodiment of the present disclosure, the included angle between each of the transflective elements and the light emitting surface is a first included angle, and the first included angle and the light is totally reflected on the light emitting surface. The sum of the critical angles of total reflection is in the range of 60° to 120°.

For example, in the embodiment of the present disclosure, the reflectivity of the transflective elements in the transflective element array arranged in sequence along the extending direction of the light exit surface gradually increases in the propagation direction of the light or gradually increases regionally. and/or the arrangement density of the transflective elements arranged in sequence along the extending direction of the light exit surface in the transflective element array gradually increases or increases regionally.

For example, in an embodiment of the present disclosure, at least some of the plurality of transflective elements included in the transflective element array are sequentially arranged along a first direction and along a second direction intersecting with the first direction By extension, the light source portion includes a plurality of sub-light sources arranged along the second direction, the plurality of sub-light sources being configured to emit light entering the at least partially transflective element.

For example, in the embodiment of the present disclosure, at least one transflective element in the transflective element array includes a selective transmission film, the light entering the optical waveguide element includes first light and second light with different characteristics, the The selective transmission film is configured such that the reflectivity for the first light is greater than the reflectivity for the second light, and the transmittance for the second light is greater than the transmittance for the first light.

For example, in an embodiment of the present disclosure, the light emitted by the light source part includes first polarized light and second polarized light with different polarization states, and the display panel is configured to use the first polarized light or the second polarized light Polarized light produces image rays. The display device further includes a light conversion device, the light conversion device includes a beam splitting element, a direction changing element and a polarization conversion element, the beam splitting element is located on the side of the display panel facing the optical waveguide element, and is is configured to split the light incident on the beam splitting element into a first polarized beam and a second polarized beam with different polarization states, the first polarized beam is directed towards the display panel, and the second polarized beam is directed towards the direction changing element; the direction changing element is configured to change the propagation direction of the light beam incident on the direction changing element so as to be directed toward the display panel; the polarization converting element is configured to convert the first Among the polarized light beams and the second polarized light beams, the polarized light beams that cannot be utilized by the display panel are converted into polarized light beams that can be utilized by the display panel before reaching the display panel.

For example, in an embodiment of the present disclosure, the display device further includes: at least one light diffusing element located on at least one of the side where the display surface of the display panel is located and the back side, and configured to disperse the display Light emitted from at least one of the panel and the optical waveguide element is diffused.

For example, in an embodiment of the present disclosure, the display device further includes: a light condensing element, located between the optical waveguide element and the display panel, and configured to converge the light emitted from the optical waveguide element and then make The concentrated light rays are directed towards the at least one light diffusing element.

For example, in an embodiment of the present disclosure, the reflective imaging portion includes a windshield of the traffic equipment.

Description of drawings

In order to explain the technical solutions of the embodiments of the present disclosure more clearly, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only relate to some embodiments of the present disclosure, rather than limit the present disclosure. .

1A is a schematic partial cross-sectional structural diagram of a display device provided according to an example of an embodiment of the present disclosure;

1B is a schematic partial cross-sectional structural diagram of a display device provided according to an example of an embodiment of the present disclosure;

FIG. 2 is a schematic plan view of a backlight source according to the example shown in FIG. 1A;

3 is a schematic plan view of another backlight source according to the example shown in FIG. 1A;

4A is a schematic plan view of another backlight source according to the example shown in FIG. 1A;

4B is a schematic plan view of another backlight source according to the example shown in FIG. 1A;

FIG. 5 is a schematic plan view of another backlight source according to the example shown in FIG. 1A;

FIG. 6 is an example in which the light emitted from the transflective element array is not perpendicular to the main surface of the waveguide medium;

7 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure;

8 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure;

9 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure;

FIG. 10 is a schematic partial structure diagram of a backlight source in another example according to an embodiment of the present disclosure;

FIG. 11 is a partial structural schematic diagram of a backlight source in another example according to an embodiment of the present disclosure;

FIG. 12 is a schematic partial structure diagram of a backlight source in another example according to an embodiment of the present disclosure;

FIG. 13 is a partial structural schematic diagram of a backlight source in another example according to an embodiment of the present disclosure;

14 is a schematic diagram of a partial structure of a backlight provided according to an example of another embodiment of the present disclosure;

FIG. 15 is a schematic partial structure diagram of a backlight provided according to an example of another embodiment of the present disclosure;

FIG. 16 is an example diagram of the backlight shown in FIG. 15;

FIG. 17 is a partial structural schematic diagram of a backlight provided according to another example of another embodiment of the present disclosure;

FIG. 18 is a schematic partial structure diagram of a backlight provided according to another example of another embodiment of the present disclosure;

FIG. 19 is an example diagram of the backlight shown in FIG. 18;

20 is a schematic partial structural diagram of a backlight provided according to yet another example of another embodiment of the present disclosure;

FIG. 21 is an example diagram of the backlight shown in FIG. 20;

22 is a schematic diagram of a partial structure of a backlight provided according to an example of still another embodiment of the present disclosure;

FIG. 23 is a schematic cross-sectional structure diagram of the backlight shown in FIG. 22;

FIG. 24 is a schematic partial structure diagram of a backlight provided according to another example of still another embodiment of the present disclosure;

FIG. 25 is a schematic partial structural diagram of a display device provided according to an example of yet another embodiment of the present disclosure;

FIG. 26 is a schematic partial structural diagram of a display device provided according to another example of yet another embodiment of the present disclosure;

27 is a schematic partial structural diagram of a display device provided according to another example of still another embodiment of the present disclosure;

FIG. 28 is a schematic partial structural diagram of a display device provided according to another example of still another embodiment of the present disclosure;

29 is a schematic diagram of a light conversion device in a display device provided according to another example of yet another embodiment of the present disclosure;

30 is a schematic diagram of a light conversion device in a display device provided according to yet another example of yet another embodiment of the present disclosure;

31 is a schematic diagram of a light conversion device in a display device provided according to yet another example of yet another embodiment of the present disclosure;

FIG. 32 is a schematic partial structure diagram of a head-up display provided according to another embodiment of the present disclosure; and

33 is an exemplary block diagram of a transportation device provided according to another embodiment of the present disclosure.

Detailed ways

In order to make the purpose, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present disclosure.

Unless otherwise defined, technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. As used in this disclosure, "first," "second," and similar terms do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprises" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things.

During research, the inventors of the present application found that the backlight source in a general display device needs to be set with a long light mixing distance to ensure the uniformity of light output, and setting a long light mixing distance of the backlight source will lead to display The thickness of the device is relatively large, which affects the portability of the display device.

Embodiments of the present disclosure provide a display device, a head-up display, a traffic device, and a light source device. The display device includes a display panel having a display surface and a backside opposite to the display surface; and a backlight located on the backside of the display panel. The backlight includes an optical waveguide plate, the optical waveguide plate includes a light homogenizing part and an optical waveguide element, the optical waveguide element includes a light exit surface, and the light homogenization part and the optical waveguide element are perpendicular to the light exit surface. Arranged in sequence in the direction; the backlight further includes a light source part, the light source part is configured so that the light emitted by the light source enters the optical waveguide element after multiple total reflections in the uniform light part, and then emits light from the light The light exit surface of the waveguide element exits. In the display device provided by the present disclosure, by arranging an optical waveguide element and a light homogenizing part in the backlight source, the uniformity of the light before being transmitted to the optical waveguide element can be improved, and the area occupied by the light homogenizing part can be saved, thereby improving the The area of the light-emitting surface of the backlight source to obtain uniform light from the surface light source.

The display device, the head-up display, the traffic equipment, and the light source device provided by the embodiments of the present disclosure will be described below with reference to the accompanying drawings.

FIG. 1A is a schematic partial cross-sectional structural diagram of a display device provided according to an example of an embodiment of the present disclosure. As shown in FIG. 1A , the display device includes a display panel 10 and a backlight 20 . The display panel 10 includes a display surface 10 - 01 and a back side 10 - 02 opposite to the display surface 10 - 01 , and the backlight source 20 is located on the back side 10 - 02 of the display panel 10 . For example, the light emitted from the backlight source 20 passes through the display panel 10 and then goes toward the viewing area 30 . For example, the side of the display panel 10 facing the backlight source 20 is the non-display side, the side of the display panel 10 away from the backlight source 20 is the display side, and the viewing area 30 is located on the display side of the display panel 10, and the display side can be viewed by the user. Display the side of the image. For example, the viewing area 30 and the backlight source 20 are located on both sides of the display panel 10 .

As shown in FIG. 1A , the backlight 20 includes a light source part 100 and an optical waveguide element 200 . The optical waveguide element 200 includes a light exit surface 211 and a transflective element array 220 , and the transflective element array 220 includes a plurality of transflective elements 221 . The light source part 100 is configured such that after entering the optical waveguide element 200, the light emitted from the light source part 100 undergoes multiple total reflections at least at the light exit surface 211 of the optical waveguide element 200 and propagates to the plurality of transflective elements 221 of the transflective element array 220 in sequence. , a part of the light transmitted to each transflective element 221 of the transflective element array 220 is reflected by the transflective element 221 out of the light emitting surface 211 of the optical waveguide element 200 and then passes through the display panel 10 and propagates to each transflective element of the transflective element array 220 Another part of the light from the element 221 continues to propagate in the optical waveguide element 200 after passing through the transflective element 221 .

In the embodiments of the present disclosure, by arranging an optical waveguide element in the backlight, the thickness of the backlight can be reduced and the space occupied in the display device can be reduced while the brightness of the light is uniform, so as to improve the display effect and portability of the display device.

For example, as shown in FIG. 1A , the optical waveguide element 200 further includes a waveguide medium 210 . The light emitted by the light source part 100 enters the waveguide medium 210 and propagates through total reflection in the waveguide medium 210 , and propagates to each transflective element of the transflective element array 220 . A part of the light from 221 is reflected out of the optical waveguide element 200 by the transflective element 221 , and the other part is transmitted through the transflective element 221 and continues to propagate through total reflection.

For example, the transflective element array 220 includes a plurality of transflective elements 221 , and the light transmitted to each transflective element 221 is transmitted and reflected on the transflective element 221 . For example, a part of the light incident on the surface of the transflective element 221 is reflected out of the optical waveguide element 200 by the transflective element 221, while the other part of the light is transmitted through the transflective element 221 and then continues to be totally reflected and propagated to the next transflective element 221, In addition, transmission and reflection occur on the next transflective element 221, and the transmitted light will continue to be totally reflected and propagated to one transflective element 221 farthest from the light source part 100 (for example, the light passes through the transmission of multiple transflective elements in sequence until it is farthest from the light source part. a transflective element). For example, all or part of the light transmitted to a transflective element farthest from the light source part may be reflected by the transflective element, which is not limited in this embodiment of the present disclosure.

For example, as shown in FIG. 1A , the light emitting surface 211 of the optical waveguide element 200 and the display surface 10 - 01 of the display panel 10 are stacked in a direction perpendicular to the display surface 10 - 01 , and the light source part 100 is located on the side of the optical waveguide element 200 . side. In the embodiment of the present disclosure, the optical waveguide element is located below the display panel and the light source part is located at the side of the optical waveguide element as an example, but it is not limited to this. For example, the display panel 10 includes a display surface for displaying images, and the light-emitting surface of the optical waveguide element 200 is located on the side of the display panel 10 away from the display surface thereof, for example, below the display panel 10, rather than the side of the display panel 10; The light source part 100 is located at the side of the optical waveguide element 200 , that is, the backlight source 20 is an edge-lit backlight source.

For example, the light source section 100 is configured to output collimated light. For example, the light source part 100 includes a light source and a collimating element, and the collimating element is configured to convert the light with a certain divergence angle emitted by the light source into the collimated light. The "collimated light" here refers to parallel or nearly parallel light. The collimated light output from the light source part 100 can make as much light as possible meet the condition of total reflection and be utilized.

For example, the light source may be a monochromatic light source or a mixed color light source, such as a red monochromatic light source, a green monochromatic light source, a blue monochromatic light source or a white mixed color light source, the monochromatic light source can finally form a monochromatic image, and the mixed color light source can form Color image. For example, the light source may be a laser light source or a light emitting diode (LED) light source. For example, the light source part may include one light source or a plurality of light sources.

For example, the above-mentioned collimating element may comprise a convex lens, a concave lens or a Fresnel lens, or any combination of the above-mentioned lenses.

For example, the above-mentioned collimating element may comprise a convex lens, and the light source may be disposed near the focal point of the convex lens, whereby the divergent light emitted from the light source may be converted into parallel or nearly parallel collimated light rays after passing through the lens.

For example, FIG. 2 is a schematic plan view of a backlight source according to the example shown in FIG. 1A . As shown in FIG. 2 , the light emitted by the light source included in the light source part 100 may be a one-dimensional light beam, that is, a light beam mainly extending in a one-dimensional direction. For example, the light source part 100 may include a strip light strip light source, and the cross section of the light beam emitted by the light source is approximately a one-dimensional line shape, or may be a narrow strip shape.

For example, FIG. 3 is a schematic plan view of another backlight source according to the example shown in FIG. 1A . As shown in FIG. 3 , at least some of the transflective elements 221 in the plurality of transflective element arrays 220 included in the transflective element array 220 are sequentially arranged along the first direction and extend along the second direction intersecting with the first direction. For example, the number of transflective elements 221 may be 2 or more. The first direction may be the X direction, and the second direction may be the Z direction, but not limited thereto, the first direction and the second direction may be interchanged.

For example, as shown in FIG. 3 , the light source of the light source part 100 may include a plurality of sub-light sources 101 arranged along the second direction, and the plurality of sub-light sources 101 are configured to emit light entering at least part of the transflective element 221 . For example, the sub-light source 101 may be a point light source, the light source part 100 may be a combination of multiple point light sources, and the multiple sub-light sources 101 are arranged in a line shape along the second direction. In the embodiment of the present disclosure, arranging a plurality of individual sub-light sources can facilitate the replacement and disassembly of each sub-light source. For example, when any sub-light source is damaged, it can be repaired by disassembling and replacing it separately, without the need for strip-mounted light strips. The entire replacement, thereby saving costs.

For example, FIG. 4A is a schematic plan view of another backlight source according to the example shown in FIG. 1A . As shown in FIG. 4A , the transflective element array 200 includes a plurality of transflective elements 220 extending along the second direction, and the light source part 100 includes a plurality of beam expanders 102 arranged along the second direction and a plurality of beam expanders 102 located in the On one side of the sub-light source 101 in the second direction, the plurality of beam expanders 102 are configured to expand the light beam emitted by the sub-light source 101 along the second direction, and the beam-expanded light is configured to be transmitted to the transflective element array 220.

For example, the light source included in the light source part 100 may be a single point light source 101 that emits a single point light beam. For example, the point light source can be a laser light source. The beam cross section of the light source is very small and the light energy is highly concentrated. Therefore, the beam emitted by the point light source can be expanded in one-dimensional direction, and the expanded light can pass through the waveguide medium and The array of transflective elements is transformed into a surface light source.

For example, as shown in FIG. 4A , the light emitted by the point light source 101 first passes through a plurality of beam expanders 102 to expand and expand in the second direction, and then is transmitted to the transflective element array 220 along the first direction. For example, when the light emitted by the point light source 101 extends and propagates through beam expansion, it can propagate along any one or more propagation modes among the reflection path, the total reflection path and the straight path.

For example, the beam expander 102 may be a grating, or may also be another array of transflective elements, which is not limited in this embodiment of the present disclosure.

For example, the light source can use an edge-type manner to guide light into the optical waveguide element, which can avoid further increasing the thickness of the backlight source.

For example, when the backlight provided by the embodiments of the present disclosure is applied to a display device that requires high brightness, such as a head-up display, a light source that emits a one-dimensional light beam (for example, a light strip or a plurality of linearly arranged point light sources) can be used. Provide high brightness for the backlight, and the solution is simple and easy to implement.

For example, FIG. 4B is a schematic structural diagram of another backlight source. The difference between the backlight shown in FIG. 4B and the backlight shown in FIG. 4A is that the beam expander is located in the optical waveguide element.

For example, as shown in FIG. 1A , the optical waveguide element 200 further includes an optical coupling part 230 located on the side of the transflective element array 220 facing the light source part 100 , and is configured so that the light entering the optical waveguide element 200 satisfies the total reflection condition, so that the Total reflection propagates in the waveguide medium 210 . The embodiments of the present disclosure are not limited to the optical waveguide element including the optical coupling portion. For example, the optical waveguide element may not include the optical coupling portion. When the angle of the light incident on the waveguide medium satisfies the condition of total reflection, the light can be implemented in the waveguide medium. of total reflection propagation.

For example, the refractive index of the waveguide medium is n1, the refractive index of the optically sparser medium (such as air) other than the waveguide medium is n2, and the incident angle of the light entering the waveguide medium or the incident angle after passing through the light coupling part is not less than the total reflection critical angle arcsin(n2/n1), the ray satisfies the condition of total reflection.

For example, the light coupling part 230 in the embodiment of the present disclosure may include at least one of a surface grating, a volume grating, a blazed grating, a prism and a reflective structure, and the light emitted by the light source enters the light source through at least one of reflection, refraction and diffraction effects. The waveguide medium makes it meet the condition of total internal reflection and then conduct.

For example, as shown in FIG. 1A , the optical waveguide element 200 includes two first and second main surfaces 211 and 212 opposite to each other, and the light coupling part 230 may be disposed on the first and second main surfaces 211 and 212 , It can also be provided on the side connecting the two main surfaces. For example, the two main surfaces of the optical waveguide element may also be referred to as the two main surfaces of the waveguide medium. For example, an array of transflective elements is located between the first major surface and the second major surface. For example, the light rays propagate on the first main surface and/or the second main surface at least by total reflection, and there may also be partial non-total reflection, such as specular reflection.

For example, when the optical waveguide element includes a plurality of sub-optical waveguide elements, for example, the plurality of sub-optical waveguide elements are arranged in an overlapping manner along a direction perpendicular to the first main surface, the upper surface of the uppermost sub-optical waveguide element is the first main surface, and the lowermost side is the first main surface. The lower surface of the sub-optical waveguide element is the second main surface.

For example, the first main surface 211 and the second main surface 212 include an upper surface 211 close to the display panel 10 and a lower surface 212 away from the display panel 10 , and the light coupling part 230 may be disposed on the upper surface 211 or the lower surface 212 and located at The transflective element array 220 faces the side of the light source part 100 . For example, the first direction (X direction) and the second direction (Z direction) are parallel to the above-mentioned main surface.

For example, the waveguide medium 210 is made of a material that can realize a waveguide function, and is generally a transparent material with a refractive index greater than 1. For example, the material of the waveguide medium 210 may include one or more of silicon dioxide, lithium niobate, silicon-on-insulator (SOI, Silicon-on-insulator), high molecular polymers, III-V semiconductor compounds and glass, etc. kind.

For example, the waveguide medium 210 may be a flat substrate, a strip substrate, a ridge substrate, or the like. For example, in at least one example of the embodiments of the present disclosure, a planar substrate is used as the waveguide medium to form a uniform surface light source.

For example, as shown in FIGS. 1A to 3 , the transflective element array 220 includes a plurality of transflective elements 221 arranged along the propagation direction of total light reflection. The direction, for example, the first direction shown in FIG. 1A (ie, the X direction), the light entering the optical waveguide element 200 undergoes total internal reflection on the two main surfaces of the waveguide medium 210, so that the light as a whole propagates along the X direction to the transparent direction. Anti-element array 220.

For example, as shown in FIGS. 1A to 3 , the transflective element 221 is configured to transmit light while reflecting light. For example, when the light transmitted by total reflection in the waveguide medium 210 is transmitted to the transflective element 221, the light is reflected at the transflective element 221, and the angle of the reflected light no longer meets the condition of total reflection, and then exits; the transmitted light is Continue to propagate along the total reflection path, continue to transmit to the next transflective element 221, continue to reflect and transmit, the light reflected by the next transflective element 221 exits from the optical waveguide element 200, passes through the next transflective element 221 The transmitted light continues to propagate along the total reflection path; and so on, until it is transmitted to the last transflective element 221 .

For example, as shown in FIG. 1A , the transflective element 221 may be disposed in the waveguide medium 210 by means of plating or cladding. For example, the waveguide medium 210 may be divided into a plurality of parallelogram columns, and transflective elements 221 are arranged between the spliced columns, that is, the medium between adjacent transflective elements 221 may be the waveguide medium 210 . For example, the waveguide medium 210 includes a plurality of waveguide sub-mediums arranged along the first direction and attached to each other, a transflective element 221 is sandwiched between adjacent waveguide sub-mediums, and each waveguide sub-medium is configured to cause total internal reflection of light, The transflective element is configured to couple a portion of the light out of the optical waveguide element by reflection that destroys total reflection conditions for that portion of the light.

For example, the embodiment of the present disclosure is described by taking the example that the plurality of transflective elements 221 in the transflective element array 220 are all parallel to each other, and the light emitted from the transflective element array at this time is parallel light. However, the embodiments of the present disclosure are not limited to this, and the plurality of transflective elements in the transflective element array may not be parallel. By adjusting the angle between the plurality of transflective elements, the light emitted from the transflective element array can be adjusted to Convergence or Divergence.

For example, as shown in FIG. 1A , the included angle between each transflective element 221 and the light-emitting surface 211 is the first included angle, and the sum of the first included angle and the critical angle of total reflection at which the light is totally reflected on the light-emitting surface 211 is 60° °～120° range. For example, the sum of the first included angle and the total reflection critical angle is in the range of 70°˜120°. For example, the sum of the first included angle and the total reflection critical angle is in the range of 80°˜100°. For example, the sum of the first included angle and the total reflection critical angle is in the range of 85°˜95°. In the embodiment of the present disclosure, by setting the sum of the first angle between the transflective element and the light-emitting surface and the total reflection critical angle of the light when the light is totally reflected on the light-emitting surface, for the same light, the light can only be A reflection occurs in each transflective element, such as avoiding transmission and reflection of light parallel or nearly parallel to the transflective element, which can improve the uniformity of light and reduce or avoid the generation of stray light.

For example, the included angle between each transflective element 221 and the first main surface 211 is the first included angle, and the included angle between the light propagating through total reflection in the waveguide medium 210 and the first main surface 211 and the second main surface 212 is the second included angle The included angle, the difference between the first included angle and the second included angle is not more than 10 degrees. For example, the difference between the first included angle and the second included angle is not more than 5 degrees. For example, the first included angle and the second included angle are equal, that is, the light propagating through total reflection in the waveguide medium 210 is parallel to the transflective element 221, and for the same light, the light can only occur once in each transflective element Reflection, such as avoiding the transmission and reflection of light parallel to the transflective element, can improve the uniformity of the light and reduce or avoid the generation of stray light.

For example, the above-mentioned first included angle and second included angle may both be acute angles.

For example, FIG. 1B is a schematic diagram of a partial structure of another display device. The difference between FIG. 1B and the example shown in FIG. 1A is that the reflection device 600 is provided on the side of the optical waveguide element 200 away from the display panel 10 , and the angle between the transflective element 221 and the light propagating through total reflection may not be limited. For example, it can be non-parallel, for example, greater than 10 degrees. In this case, by arranging a reflection device on the side of the optical waveguide element away from the display panel, the leaked stray light can be reflected back to improve the uniformity of the light emitted from the optical waveguide element. For example, the above-mentioned reflecting device may be a reflecting layer or other structures capable of reflecting.

For example, as shown in FIG. 1A to FIG. 3 , the embodiment of the present disclosure schematically shows that the orthographic projections of adjacent transflective elements 221 on the main surface are connected to each other, which can avoid the occurrence of darkness between the two transflective elements without light. area. But not limited to this, the orthographic projections of adjacent transflective elements on the main surface may partially overlap, which can avoid the weakening of light at the edges of the transflective elements, and the overlapping of the transflective elements can make the light output more uniform.

For example, as shown in FIGS. 1A to 3 , along the direction of total reflection and propagation of light in the waveguide medium 210 , the plurality of transflective elements 221 are uniformly arranged and the reflectivity gradually increases. For example, the reflectance of the transflective element 221 that is closer to the light source unit 100 is smaller. For example, the reflectivity of the transflective elements arranged in sequence along the extending direction of the light exit surface in the transflective element array gradually increases in the propagation direction of the light or increases regionally. For example, in the transflective element array, the arrangement density of the transflective elements sequentially arranged along the extending direction of the light exit surface gradually increases or increases regionally. For example, the regional increase may be two or more regions in which the reflectivity of the transflective element is different and gradually increases.

The above-mentioned uniform arrangement may refer to either an arrangement in which adjacent transflective elements are arranged with orthographic projections adjoining each other, or an arrangement in which adjacent transflective elements are arranged with orthographic projections partially overlapping. Since the light will gradually reflect out of the waveguide medium during the propagation process, the light intensity will gradually attenuate. Therefore, by setting the transflective properties of each transflective element to be different, for example, along the path of total reflection of the light, the reflection of the transflective element The rate of light increases gradually, so that the intensity of the light reflected by each transflective element is relatively uniform, and the light output from each part of the waveguide medium 210 is relatively uniform.

For example, along the direction of total reflection and propagation of light in the waveguide medium, the arrangement density of the plurality of transflective elements gradually increases. For example, the arrangement density of the partially transflective elements is smaller as it is closer to the light source portion. For example, the position with a low arrangement density may be that the adjacent transflective elements are arranged so that the orthographic projections are adjacent to each other, and the position of the above-mentioned arrangement density may be that the adjacent transflective elements are arranged so that the orthographic projections partially overlap. For example, the position with a low arrangement density may be that adjacent transflective elements are set to overlap each other with orthographic projection, and the overlapping part is small, and the position with a large arrangement density can be set to the orthographic projection of adjacent transflective elements. They overlap each other, and the overlapping part is larger. In the embodiment of the present disclosure, the transflective properties of the transflective elements can also be set to be the same or almost the same, and the intensity of the light reflected by the transflective elements can be made uniform by adjusting the arrangement density of the transflective elements.

For example, FIG. 5 is a schematic plan view of another backlight source according to the example shown in FIG. 1A . The difference between the backlight shown in FIG. 5 and the backlight shown in FIG. 3 is that the reflectance of the transflective elements in the transflective element array varies. For example, in the example shown in FIG. 5 , the transflective element array 220 includes at least two regions, such as region 01 and region 02 , and the average reflectivity of the transflective element 221 in one region 01 of the at least two regions is greater than that of the other regions Average reflectance of transflective elements 221 within (eg, area 02). The average reflectivity of the transflective elements in the above area 01 is greater than the average reflectivity of the transflective elements in other areas, so that the light intensity in the area 01 is stronger than that in other areas. Of course, the embodiment of the present disclosure is not limited to adjusting the transflective in the area. The average reflectivity of the element can adjust the light intensity of the outgoing light in the area, and the intensity of the outgoing light in the area can also be adjusted in other ways.

For example, the area 01 may include at least one transflective element 221, the other area 02 may include a plurality of transflective elements 221, and the average reflectivity of the plurality of transflective elements 221 in the other areas is small so that the optical waveguide element can emit light. The brightness of the light is uneven, and the optical waveguide element is suitable for application scenarios with uneven display, such as billboards and displays that display content in a specific area. For example, area 01 may be located in the middle area, and other areas 02 may surround area 01. The embodiments of the present disclosure are not limited thereto, for example, the reflectivity of the plurality of transflective elements 221 included in the region 01 is gradually increased, while the reflectivity of the plurality of transflective elements 221 in other regions is the same, so that the optical waveguide element The emitted light is uneven in brightness.

For example, the transflective element 221 can transmit and reflect light without wavelength selectivity and polarization selectivity. For example, an inorganic dielectric film layer is used, for example, one or more layers of metal oxide/metal nitride are stacked. The thickness of each layer is about 10nm-1000nm, and the overall transmission and reflection properties of the inorganic dielectric layer can be adjusted by changing the layer material and/or the layer stacking method. Thus, the wavelength properties and polarization properties of the light incident on the transflective element 221 are almost unchanged after being transmitted and reflected by the transflective element 221 .

For example, at least one transflective element 221 in the transflective element array 220 includes a selective transmission film, the light entering the optical waveguide element 200 includes a first polarized light and a second polarized light, and the selective transmission film is configured to reflect the first polarized light. The reflectivity of the second polarized light is greater than that of the second polarized light, and the transmittance of the second polarized light is greater than that of the first polarized light, so that the transflective element can gradually reflect the first polarized light out of the optical waveguide element.

The above-mentioned light entering the optical waveguide element may be unpolarized light, or may be directly polarized light with two polarization states. The "unpolarized light" here means that the light emitted by the light source can have multiple polarization characteristics at the same time but does not exhibit a unique polarization characteristic. That is, the non-polarized light emitted by the light source part can be decomposed into two mutually perpendicular polarized light rays.

For example, the selective transmission film may be a brightness enhancement film (BEF), which has a high reflectivity for one polarized light and a high transmittance for another polarized light (for example, a selective transmission film for S polarized light) The light reflectivity is high, and the transmittance to P polarized light is high), and the transflective element can utilize the selectivity of polarization transflectance, so that the light is gradually reflected by the transflective element and out of the optical waveguide element.

For example, as shown in FIG. 1A , when the light emitted from the transflective element array 220 does not meet the total reflection condition, the output direction may be a direction perpendicular to the main surface of the waveguide medium 210 .

FIG. 6 is an example in which the light emitted from the transflective element array is not perpendicular to the main surface of the waveguide medium. As shown in FIG. 6 , when the angle of the light incident on the transflective element is changed, and/or the angle between the transflective element and the main surface is changed, the light emitted from the transflective element array can also interact with the main surface of the waveguide medium. The surface is not vertical.

In the embodiment of the present disclosure, the light emitted from the transflective element array can be perpendicular or non-perpendicular to the main surface of the waveguide medium, and the outgoing directions of the light rays emitted from different transflective elements are parallel or nearly parallel to form a collimated beam. In the embodiment of the present disclosure, the light output from the light source is converted into the light of the surface light source that is collimated by using an optical waveguide element with a smaller thickness, which can save the thickness of the display device.

FIG. 7 is a partial structural schematic diagram of a backlight source in another example according to an embodiment of the present disclosure. The example shown in FIG. 7 is different from the example shown in FIG. 1A in that the number of light source parts and the arrangement of the transflective elements are different, and the positional relationship of adjacent transflective elements can be the same as the example shown in FIG. 1A . As shown in FIG. 7 , the transflective element array 220 includes a first transflective element group 2201 and a second transflective element group 2202 arranged along the first direction, and each transflective element group includes a plurality of transflective element groups arranged along the first direction For the elements 221, the transflective elements 221 of different transflective element groups are not parallel. For example, FIG. 7 schematically shows that a plurality of transflective elements included in each transflective element group are parallel to each other, and the transflective elements in different transflective element groups are not parallel.

For example, as shown in FIG. 7 , the light source part 100 includes a first light source part 110 and a second light source part 120 , the first light source part 110 and the second light source part 120 are respectively located on both sides of the transflective element array 220 in the first direction, The first transflective element group 2201 is configured to reflect light entering the optical waveguide element 200 from the first light source part 110 , and the second transflective element group 2202 is configured to reflect light entering the optical waveguide element 200 from the second light source part 120 . For example, the first transflective element group 2201 is configured to reflect only light entering from the first light source part 110 , and the second transflective element group 2202 is configured to reflect only light entering from the second light source part 2202 . In the embodiment of the present disclosure, by arranging two light source parts and two sets of transflective element groups, the intensity of light emitted from the optical waveguide element can be improved.

For example, as shown in FIG. 7 , one of the transflective elements 221 in the first transflective element group 2201 and the transflective elements 221 in the second transflective element group 2202 is related to the first direction (the direction indicated by the arrow of X) The angle between them is an acute angle, and the angle between the other and the first direction is an obtuse angle. The first transflective element group can only reflect the light entering from the first light source part, and the second transflective element group can only reflect light from The light entered by the second light source part. For example, the transflective elements 221 in the first transflective element group 2201 and the transflective elements 221 in the second transflective element group 2202 have different inclination directions.

For example, the light source part may also be located between the first transflective element group and the second transflective element group in the extending direction of the light emitting surface.

For example, a reflection device may also be provided in the backlight source, and the reflection device may be arranged on the other side away from the light-emitting surface of the optical waveguide element to reflect the light leaked from the optical waveguide element back to the optical waveguide element, so that as much light as possible Convert it into collimated light and output it to improve light utilization.

For example, FIG. 8 is a schematic partial structure diagram of a backlight source in another example according to an embodiment of the present disclosure. The difference between the example shown in FIG. 8 and the example shown in FIG. 1A lies in the number of light source parts and the outgoing direction of light reflected from the light source part by the transflective element. As shown in FIG. 8 , the light source part 100 includes a first light source part 110 and a second light source part 120 , the first light source part 110 and the second light source part 120 are respectively located on both sides of the transflective element array 220 in the first direction. Both side surfaces of each transflective element 221 can reflect the light entered by the first light source part 110 or the second light source part 120 , so that both sides of the main surfaces of the optical waveguide element are light emitting surfaces.

For example, the reflectivity of the transflective element at and/or near the middle position is greater than that of the transflective element at both sides, so that the light emitted from the optical waveguide element has better uniformity. The backlight in this example can be applied to scenes that require light to be emitted from both sides, such as billboards.

For example, FIG. 9 is a schematic partial structure diagram of a backlight source in another example according to an embodiment of the present disclosure. As shown in FIG. 9 , the backlight further includes a light splitting element 300 located between the light source part 100 and the optical waveguide element 200 . The light splitting element 300 is configured to divide the light emitted from the light source part 100 to the optical waveguide element 200 into a plurality of sub-beams. For example, the light splitting element 300 can divide the light emitted by the light source part 100 to the optical waveguide element 200 into two sub-beams or three sub-beams, the embodiment of the present disclosure is not limited thereto, and can also be divided into more sub-beams. For example, the light splitting element 300 may be a prism.

For example, as shown in FIG. 9 , the optical waveguide element 200 includes a plurality of sub-optical waveguide elements 201 , and a plurality of sub-beams are configured to enter the plurality of sub-optical waveguide elements 201 and are arranged in the transflective element array in each sub-optical waveguide element 201 . 221 is reflected out of the optical waveguide element 200 . For example, the transflective element array includes a plurality of sub-transflective element arrays respectively located in a plurality of sub-optical waveguide elements. For example, a plurality of sub-transflective element arrays are in one-to-one correspondence with a plurality of sub-optical waveguide elements.

For example, the number of the plurality of sub-optical waveguide elements 201 may be the same as the number of the plurality of sub-beams. In this case, the plurality of sub-beams are configured to enter the corresponding sub-optical waveguide elements one by one. The embodiment of the present disclosure is not limited thereto, and the number of the sub-optical waveguide elements may also be smaller than the number of the sub-beams. In this case, at least two sub-beams enter the same sub-optical waveguide element.

For example, the thicknesses of the plurality of sub-optical waveguide elements 201 are smaller than the thicknesses of the optical waveguide elements in the embodiment shown in FIG. 1A ; the light originally transmitted in one optical waveguide element is split into multiple beams and then coupled into multiple optical waveguide elements. With thinner waveguide components, the light is transmitted in the waveguide components with smaller thickness, and the number of total reflections will increase, which can make the light distribution more uniform. For example, the uniformity in this embodiment may mean that the light is evenly bright and dark. Generally, the light emitted by a light source (such as a point light source) has a strong middle light and a darker edge. The straight light is also bright in the middle and dark on both sides, and it is difficult to adjust the brightness of the collimated light; therefore, before the light emitted by the light source enters the optical waveguide element or is coupled out from the optical waveguide element, the By improving the uniformity of light, light and dark uniform surface light sources can be obtained; for example, increasing the number of total reflections of light can improve the uniformity of light and dark, so thinner optical waveguide elements can be set to increase the number of total reflections of light.

In the embodiment of the present disclosure, by dividing the light of the light source part into a plurality of sub-beams and arranging a plurality of sub-optical waveguide elements to couple out the plurality of sub-beams entering therein, the uniformity of light output from the backlight can be further improved.

For example, the plurality of sub-optical waveguide elements may be independent structures, or may be integrated on the same substrate.

For example, each sub-optical waveguide element includes a waveguide medium, and the refractive index of the waveguide medium in different sub-optical waveguide elements may be the same or different, which is not limited in this embodiment of the present disclosure.

For example, the number and arrangement of the transflective elements included in the transflective element array in each sub-optical waveguide element may be the same or different, which is not limited in this embodiment of the present disclosure.

For example, each sub-optical waveguide element may or may not include an optical coupling portion. For example, when each sub-optical waveguide element includes an optical coupling part, the optical coupling parts of different sub-optical waveguide elements can be the same, for example, they all enter in a geometrical manner (for example, non-grating coupling such as prism coupling or reflective structure coupling). , may also be different, which is not limited in this embodiment of the present disclosure.

For example, as shown in FIG. 9 , the optical waveguide element 200 includes a plurality of sub-optical waveguide elements 201 , the transflective element array 210 includes a plurality of sub-transflective element arrays respectively located in the plurality of sub-optical waveguide elements 201 ; the backlight further includes a light splitting element 300 The spectroscopic element 300 is configured to divide the light emitted by the light source part 100 toward the optical waveguide element 200 into a plurality of sub-beams and make the plurality of sub-beams enter into the plurality of sub-optical waveguide elements 201 respectively, and enter each of the sub-optical waveguide elements 201 Each of the sub-beams is reflected out of the light-emitting surface of the optical waveguide element 200 by the sub-transflective element array located in each sub-optical waveguide element 201 .

For example, the light emitted by the light source unit 100 and directed toward the optical waveguide element 200 includes first characteristic light and second characteristic light with different characteristics, and the spectroscopic element 300 is configured to perform a ray of light emitted by the light source unit 100 toward the optical waveguide element 200 . In the spectral processing, the first characteristic light obtained by the spectral processing is incident on the first sub-optical waveguide element 2011 , and the second characteristic light obtained by the spectral processing is incident on the second sub-optical waveguide element 2012 .

For example, the first characteristic light and the second characteristic light are the first polarized light and the second polarized light with different polarization states, respectively; or, the first characteristic light and the second characteristic light are the first color light and the second light with different colors, respectively Color light.

For example, the light splitting element includes a polarizing light splitting element configured to reflect one of the first polarized light and the second polarized light and transmit the other of the first polarized light and the second polarized light. The beam splitting element further includes a reflective element configured to reflect one of the first polarized light and the second polarized light.

For example, as shown in FIG. 9 , the plurality of sub-beams include a first polarized beam 1001 and a second polarized beam 1002 with different polarization directions, the beam splitting element 300 includes a polarizing beam splitting element 310 , and the polarizing beam splitting element 300 is configured to emit light from the light source unit 100 . The light incident on the optical waveguide element 200 is subjected to polarization splitting processing, so that the plurality of sub-beams include a first polarized beam 1001 and a second polarized beam 1002 with different polarization states, and the second polarized beam 1002 is incident on the second sub-optical waveguide element 2012 , and the first polarized light beam 1001 is incident on the first sub-optical waveguide element 2011 . The above-mentioned polarizing beam splitting element transmits the second polarized beam and reflects the first polarized beam, and is not limited to only reflecting the second polarized beam and transmitting the first polarized beam. For example, the polarizing beam splitting element has a high transmittance to the second polarized beam. The reflectivity of a polarized light beam is high. The first polarized light beam and the second polarized light beam in the embodiments of the present disclosure may be interchanged.

For example, as shown in FIG. 9 , the transflective element of the first sub-optical waveguide element 2011 is configured so that the reflectivity of the first polarized light is greater than the reflectivity of the second polarized light, and the transflective element of the second sub-optical waveguide element 2012 The element is configured so that the reflectivity of the second polarized light is greater than the reflectivity of the first polarized light, which can improve the intensity of the light emitted by the backlight source and improve the utilization rate of the light.

Of course, the embodiment of the present disclosure is not limited to this, and the transflective element in each sub-optical waveguide element may also have no polarization selective characteristic.

For example, as shown in FIG. 9 , the spectroscopic element 300 further includes a reflection element 320 , and the reflection element 320 is configured to reflect the first polarized light beam 1001 into the first sub-optical waveguide element 2011 . Embodiments of the present disclosure are not limited thereto, and the reflective element may also be configured to reflect the second polarized light beam into the second sub-optical waveguide element. For example, the function of the reflective element is to transmit the split first polarized light beam to the first sub-optical waveguide element, and the reflective element can be replaced by other elements with similar functions.

For example, after the unpolarized light emitted by the light source part 100 passes through the polarization beam splitting element 310 having the polarization beam splitting function, the transmitted light includes P-polarized light (eg, the second polarized light), and the reflected light includes S-polarized light (eg, the first polarized light) ); or the transmitted light includes S-polarized light (eg, second polarized light), and the reflected light includes P-polarized light (eg, first polarized light), which is not limited in this embodiment of the present disclosure.

For example, the polarization beam splitting element 310 may have the function of transmitting light of one characteristic and reflecting light of another characteristic, for example, the polarization beam splitting element 310 may have the characteristic of transmitting light of one polarization state and reflecting light of another polarization state , the polarization beam splitting element 310 can realize beam splitting by utilizing the above-mentioned transflective characteristics.

For example, the polarized light splitting element 310 can be a transflective film, which realizes the beam splitting effect by transmitting part of the light and reflecting another part of the light. For example, the transflective film may transmit the second polarized light in the light emitted by the light source part 100 and reflect the first polarized light in the light emitted by the light source part 100 .

For example, the transflective film can be an optical film with polarized transflective function, specifically, an optical film that can split unpolarized light into two mutually perpendicularly polarized lights through transmission and reflection; the above-mentioned optical film can be composed of multiple layers The film layers with different refractive indices are combined in a certain stacking order, and the thickness of each film layer is about 10-1000nm; the material of the film layer can be selected from inorganic dielectric materials, such as metal oxides and metal nitrides; Polymeric materials such as polypropylene, polyvinyl chloride or polyethylene can also be selected.

For example, the transmitted P-polarized light enters the second sub-optical waveguide element 2012 through the second optical coupling part 232 in the second sub-optical waveguide element 2012 , and the reflected S-polarized light is reflected by the reflective element 320 and then enters the first sub-light The first optical coupling part 231 in the waveguide element 2011 enters the first sub-optical waveguide element 2011 . The S-polarized light and the P-polarized light are output in the state of collimated light through the transflective element arrays in their respective waveguide elements, which can realize the effect of converting an ordinary light source into a uniform surface light source.

For example, as shown in FIG. 9 , a plurality of sub-optical waveguide elements are arranged to overlap in a direction perpendicular to the display surface of the display panel, thereby improving the brightness of the backlight and improving the uniformity of light. The above-mentioned overlapping arrangement includes a complete overlapping arrangement and a partial overlapping arrangement, that is, the orthographic projections of the plurality of sub-optical waveguide elements on a plane parallel to the light-emitting surface of the optical waveguide element can be completely overlapped or partially overlapped. The example does not limit this. FIG. 9 schematically shows that the first sub-optical waveguide element and the second sub-optical waveguide element are completely overlapped.

For example, as shown in FIG. 9 , the first sub-optical waveguide element 2011 and the second sub-optical waveguide element 2012 overlap in a direction perpendicular to the display surface of the display panel, that is, the first sub-optical waveguide element 2011 and the second sub-optical waveguide element The elements 2012 overlap in the Y direction, and the light emitted from the second sub-optical waveguide element 2012 passes through the first sub-optical waveguide element 2011 and then goes toward the display panel. For example, as shown in FIG. 9 , the light emitted from the second sub-optical waveguide element 2012 may pass through the transflective element array in the first sub-optical waveguide element 2011 , or may not pass through the transflective element in the first sub-optical waveguide element 2011 The element array is not limited in this embodiment of the present disclosure.

For example, when the light emitted from the second sub-optical waveguide element passes through the transflective element array in the first sub-optical waveguide element, the transflective element array in the first sub-optical waveguide element has a higher transmittance to the transmitted light. .

For example, as shown in FIG. 9 , the angle between the first polarized light beam 1001 transmitted to the transflective element of the first sub-optical waveguide element 2011 and the transflective element is the third angle, and transmitted to the second sub-optical waveguide element 2012 The included angle between the second polarized light beam 1002 of the transflective element and the transflective element is the fourth included angle, and the difference between the third included angle and the fourth included angle is not greater than 5 degrees. Both the third angle and the fourth angle may refer to the angle between the light incident on the surface of the transflective element and the transmitted light and the transflective element.

For example, if the third included angle and the fourth included angle are equal, the angle of the polarized light entering the sub-optical waveguide element can be adjusted according to the inclination angle of the transflective element in each sub-optical waveguide element. For example, setting the included angles between different sub-optical waveguide elements and the corresponding polarized light to be the same can also facilitate the fabrication of the sub-optical waveguide elements and the adjustment of the angle of incident light.

For example, as shown in FIG. 9 , the total reflection propagation direction of the first polarized light beam 1001 entering the first sub-optical waveguide element 2011 is the same as the total reflection propagation direction of the second polarized light beam 1002 entering the second sub-optical waveguide element 2012 Meanwhile, the included angle between the transflective element in the first sub-optical waveguide element 2011 and the transflective element in the second sub-optical waveguide element 2012 may be no greater than 5 degrees, for example, the transflective element in the two sub-optical waveguide elements parallel to facilitate the fabrication of optical waveguide components.

For example, as shown in FIG. 9 , the included angles between the transflective element in the first sub-optical waveguide element 2011 and the transflective element in the second sub-optical waveguide element 2012 and the first direction are both acute angles, or both are obtuse angles . For example, the transflective elements in the first sub-optical waveguide element 2011 and the transflective elements in the second sub-optical waveguide element 2012 have the same inclination directions. The inclined direction here may refer to the inclined direction of the transflective element relative to the light-emitting surface. But it is not limited to this, and the inclination direction here may also refer to the inclination to the left or the right with respect to the Y direction.

The direction indicated by the arrow in the X direction shown in FIG. 9 is the first direction (for example, when the above-mentioned included angle with the direction is involved, the first direction can be regarded as a vector) and enters the first sub-optical waveguide element 2011. The total reflection propagation direction of a polarized light beam 1001 is the same as the total reflection propagation direction of the second polarized light beam 1002 entering the second sub-optical waveguide element 2012. When the total reflection propagation direction of each polarized light is the same as the first direction, each transparent The angle between the reflection element and the first direction is an acute angle; when the total reflection propagation direction of each polarized light is opposite to the first direction, the angle between the transflective element and the first direction is an obtuse angle.

For example, FIG. 10 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure. The example shown in FIG. 10 is different from the example shown in FIG. 9 in that the positional relationship of the plurality of sub-optical waveguide elements is different. As shown in FIG. 10 , the plurality of sub-optical waveguide elements are arranged in the first direction. For example, the plurality of sub-optical waveguide elements do not overlap in the direction perpendicular to the display surface of the display panel, which can not only reduce the thickness of the backlight, but also reduce the length of the sub-optical waveguide elements by setting the length of each sub-optical waveguide element to be smaller. The degree to which the edge light intensity is weakened. For example, the plurality of sub-optical waveguide elements do not overlap in the direction perpendicular to the display surface of the display panel, and may be just adjacent to each other, or may have a certain distance, as shown in FIG. 10 .

For example, the plurality of sub-optical waveguide elements may include a first sub-optical waveguide element 2011 and a second sub-optical waveguide element 2012 arranged along the first direction, and the second polarized light beam 1002 transmitted by the polarization splitting element 310 passes through the second sub-optical waveguide element 2012 The second optical coupling-in part 232 in the first sub-optical waveguide element 2012 enters the second sub-optical waveguide element 2012, and the reflected first polarized light beam 1001 passes through the first optical coupling-in part 231 in the first sub-optical waveguide element 2011 without passing through the reflective element to enter the first sub-light beam Waveguide element 2011. The first polarized light beam 1001 and the second polarized light beam 1002 pass through the transflective element arrays in the respective sub-waveguide elements, and are output in the state of collimated light, which can realize the effect of converting an ordinary light source into a uniform surface light source.

For example, the propagation direction of total reflection of light in the first sub-optical waveguide element 2011 is opposite to the propagation direction of total reflection of light in the second sub-optical waveguide element 2012, then the transflective element in the first sub-optical waveguide element 2011 is the same as the second sub-optical waveguide element 2011. The transflective elements in the optical waveguide element 2012 are not parallel, for example, the angle between one of them and the first direction is an acute angle, and the angle between the other and the first direction is an obtuse angle, so as to realize the outcoupling of light by the transflective element . For example, the transflective elements in the first sub-optical waveguide element 2011 and the transflective elements in the second sub-optical waveguide element 2012 have different tilt directions.

For example, FIG. 11 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure. As shown in FIG. 11 , the spectroscopic element 300 is configured to divide the light beams emitted by the light source unit 100 toward the optical waveguide element into a plurality of light beams with different wavelengths. For example, the light-splitting element 300 may include a light-splitting prism, a light-splitting grating, or the like, which may serve as elements for separating light of different wavelengths.

For example, as shown in FIG. 11 , the plurality of sub-beams include first color light 1003 and second color light 1004 with different wavelengths, the plurality of sub-optical waveguide elements 201 include a first sub-optical waveguide element 2011 and a second sub-optical waveguide element 2012, The first color light 1003 is configured to enter the first sub-optical waveguide element 2011, and is reflected out of the first sub-optical waveguide element 2011 by the transflective element array located in the first sub-optical waveguide element 2011, and the second color light 1004 is reflected from the first sub-optical waveguide element 2011. It is configured to enter the second sub-optical waveguide element 2012 and be reflected out of the second sub-optical waveguide element 2012 by the transflective element array located in the second sub-optical waveguide element 2012 .

In the embodiment of the present disclosure, by entering light of different colors into different sub-optical waveguide elements, it is beneficial to the regulation of total reflection and propagation of light of different colors, so as to improve the utilization rate of light.

For example, the transflective element of the first sub-optical waveguide element 2011 is configured so that the reflectivity for the first color light 1003 is greater than the reflectivity for the second color light 1004, and the transflective element of the second sub-optical waveguide element 2012 is configured as The reflectivity for the second color light 1004 is greater than the reflectivity for the first color light 1003 . The embodiments of the present disclosure can improve the utilization rate of light incident into the corresponding sub-optical waveguide elements by adjusting the reflectivity and transmittance of the transflective elements in different sub-optical waveguide elements.

For example, the first color light 1003 may be red light or green light, and the second color light 1004 may be blue light. The embodiment of the present disclosure is not limited thereto, and the first color light and the second color light may be interchanged.

For example, FIG. 12 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure. As shown in FIG. 12 , the plurality of sub-beams further includes a third color light 1005 configured to enter one of the first sub-optical waveguide element 2011 and the second sub-optical waveguide element 2012 . For example, as shown in FIG. 12 , the first color light 1003 and the third color light 1005 enter the first sub-optical waveguide element 2011 , and the second color light 1004 enters the second sub-optical waveguide element 2012 . The embodiment of the present disclosure is not limited thereto, and the third color light may also enter the same sub-optical waveguide element with the second color light.

In the embodiment of the present disclosure, by introducing two different colors of light into the same sub-optical waveguide element, the fabrication cost of the optical waveguide element can be reduced, and the thickness of the backlight source can also be reduced.

For example, the first color light 1003 and the third color light 1005 may be red light and green light, respectively, and the second color light 1004 may be blue light. The embodiment of the present disclosure is not limited thereto, the first color light and the third color light may also be green light and blue light, respectively, and the second color light is red light.

In the embodiment of the present disclosure, two colors of light with similar wavelengths enter the same sub-optical waveguide element, which can facilitate the adjustment of the transflective element array in the sub-optical waveguide element, and can also reduce costs.

For example, FIG. 13 is a schematic diagram of a partial structure of a backlight source in another example according to an embodiment of the present disclosure. The example shown in FIG. 13 is different from the example shown in FIG. 12 in that a plurality of light rays of different colors are arranged to enter a plurality of sub-optical waveguide elements one by one. As shown in FIG. 13 , the plurality of sub-beams further includes a third color light 1005 , the plurality of sub-optical waveguide elements 201 further includes a third sub-optical waveguide element 2013 , and the third color light 1005 is configured to enter the third sub-optical waveguide element 2013 , and is reflected out of the third sub-optical waveguide element 2013 by the transflective element array located in the third sub-optical waveguide element 2013 . The embodiments of the present disclosure can further improve the utilization rate of light by entering light of different colors into different sub-optical waveguide elements one by one.

For example, as shown in FIG. 13 , the transflective element of the first sub-optical waveguide element 2011 is configured such that the reflectivity for the first color light 1003 is greater than the reflectivity for the second color light 1004 and the third color light 1005 , the second The transflective element of the sub-optical waveguide element 2012 is configured such that the reflectivity for the second color light 1004 is greater than the reflectivity for the first color light 1003 and the third color light 1005, and the transflective element of the third sub-optical waveguide element 2013 It is configured such that the reflectance for the third color light 1005 is greater than the reflectance for the first color light 1003 and the second color light 1004 . The embodiments of the present disclosure can improve the utilization rate of light incident into the corresponding sub-optical waveguide elements by adjusting the reflectivity and transmittance of the transflective elements in different sub-optical waveguide elements.

For example, as shown in FIG. 13 , the refractive index of the waveguide medium of the first sub-optical waveguide element 2011 , the refractive index of the waveguide medium of the second sub-optical waveguide element 2012 , and the refractive index of the waveguide medium of the third sub-optical waveguide element 2013 may be are different, and each is set to accommodate the refractive index of the light entering the corresponding sub-optical waveguide element. For example, the first color light 1003, the second color light 1004 and the third color light 1005 are blue light, red light and green light respectively. If the three kinds of light are coupled into the same optical waveguide element, the light of different wavelengths propagate in the same medium, The refractive index of the medium to various light is different, so the total reflection angles of the three wavelengths of light are different (for example, the total reflection critical angle of red light is greater than the total reflection critical angle of blue light), and the angle of the transflective element should also consider three angles. Therefore, the efficiency is low; if the total reflection angles of the three types of light are to be close, it is necessary to control the medium to have different refractive indices. Therefore, by separating various kinds of light, each sub-optical waveguide element can select a medium and a corresponding transflective element that can transmit the corresponding light as far as possible to satisfy the condition of total reflection, so that the utilization rate of light can be improved.

For example, the embodiment of the present disclosure is not limited to that the sub-beams are sub-rays with different polarization directions or wavelengths, and each sub-beam in the plurality of sub-beams may also be sub-rays with the same properties, that is, the light splitting element is only configured to combine the light source part An emitted light beam is divided into a plurality of sub-beams with the same properties, and the plurality of sub-beams are configured to enter into the plurality of sub-optical waveguide elements one by one. Instead of entering a beam of light emitted by the light source part into one optical waveguide element, the embodiment of the present disclosure can improve the light output by dividing a beam of light emitted by the light source part into multiple beams of light and entering different sub-optical waveguide elements respectively. The utilization rate can also improve the uniformity of the outcoupled light. When each sub-ray in the plurality of sub-beams has the same property, the plurality of sub-optical waveguide elements may or may not overlap in a direction perpendicular to the display surface of the display panel.

For example, the optical waveguide element includes a plurality of sub-optical waveguide elements, and the plurality of sub-optical waveguide elements are arranged in a direction parallel to the display surface of the display panel or in a direction perpendicular to the display surface of the display panel. In at least one sub-optical waveguide element in the element, along the direction of total reflection and propagation of light in the waveguide medium, a plurality of transflective elements are uniformly arranged and the reflectivity gradually increases.

For example, the optical waveguide element includes a plurality of sub-optical waveguide elements, and the plurality of sub-optical waveguide elements are arranged in a direction parallel to the display surface of the display panel or in a direction perpendicular to the display surface of the display panel. In at least one sub-optical waveguide element in the element, along the direction of total reflection and propagation of light in the waveguide medium, the arrangement density of the plurality of transflective elements gradually increases.

During the research, the inventor of the present application also found that two polarizers with different light transmission directions are arranged on both sides of the liquid crystal layer of the liquid crystal display device. The light can be incident inside the liquid crystal display panel through the polarizer between the liquid crystal layer and the backlight, and be used for imaging. For example, when the light emitted by the backlight is non-polarized light, only 50% of the light emitted by the backlight can be utilized by the liquid crystal layer at most, and the rest of the light will be wasted or absorbed by the liquid crystal layer, resulting in low light utilization. question.

FIG. 14 is a schematic partial structural diagram of a backlight provided according to an example of another embodiment of the present disclosure. The backlight source in this embodiment can also be called a light source device, which can be applied to the display device together with the display panel, or can be used alone, which is not limited in this embodiment of the present disclosure. For example, the light source device in this embodiment may be disposed on the back side of the transmissive display panel, or may be disposed on the display side of the reflective display panel to provide light for the display panel. The light source device in this embodiment (for example, a backlight source ), which can be applied to any display device that requires a light source.

As shown in FIG. 14 , the light source device includes: a light source part 100, the light emitted by the light source part 100 includes a first polarized light 100-1 and a second polarized light 100-2 with different polarization states; an optical waveguide element 200, including an optical coupling Section 240. The light source part 100 is configured so that the light emitted by it enters the optical waveguide element 200 and propagates reflectively in the optical waveguide element 200 , and the light coupling out part 240 is configured to couple out the light propagating reflectively in the optical waveguide element 200 . . The light coupling out part 240 includes a first light coupling out part 241 and a second light coupling out part 242. The first light coupling out part 241 is configured to couple out the first polarized light 100-1 entering the optical waveguide element 200; the light source The apparatus further includes a polarization conversion structure 400 configured to convert the second polarized light 100-2 after entering the optical waveguide element 200 into the first polarized light 100-1. The second light coupling out part 242 is configured to: after the polarization conversion structure 400 converts the second polarized light 100 - 2 entering the optical waveguide element 200 into the first polarized light 100 - 1 , convert the converted first polarized light 100 to the first polarized light 100 - 1 . -1 out-coupling; or the second optical out-coupling part 242 is configured to: couple out the second polarized light 100-2 entering the optical waveguide element 200 to the polarization conversion structure 400, so that the out-coupled second polarized light 100 -2 is converted to the first polarized light 100-1 by the polarization conversion structure 400.

As shown in FIG. 14 , the backlight includes a light source unit 100 and an optical waveguide element 200 . The light emitted by the light source part 100 includes a first polarized light 100-1 and a second polarized light 100-2 with different polarization states. The optical waveguide element 200 includes a waveguide medium 210 and an optical coupling-out part 240 . The light emitted by the light source part 100 is configured to enter the waveguide medium 210 and propagate through total reflection in the waveguide medium 210 , and the optical coupling-out part 240 is configured to transmit light in the waveguide medium 210 . The light propagating through total reflection is coupled out to the predetermined area 40 .

For example, as shown in FIG. 14 , the first polarized beam 1001 and the second polarized beam 1002 , and the first polarized beam 1001 and the second polarized beam 1002 can be obtained respectively after the polarized light of different polarization states emitted by the light source part 100 passes through the light splitting structure. different polarization states.

For example, the first optical out-coupling part 241 is configured to out-couple the first polarized light beam 1001 entering the optical waveguide element 200 to the predetermined area 40 . As shown in FIG. 14 , the backlight further includes a polarization conversion structure 400, and the polarization conversion structure 400 is configured to convert the second polarized light beam 1002 after entering the optical waveguide element 200 into a first polarized light beam 1001'. The second light out-coupling part 242 is configured to couple out the converted first polarized light beam 1001 ′ to the predetermined region 40 , or to couple out the second polarized light beam 1002 to the polarization conversion structure 400 to convert the second polarized light beam 1002 into The first polarized light beam 1001 ′ is then directed to the predetermined area 40 .

The polarization conversion structure arranged in the backlight can convert the unpolarized light emitted from the light source into polarized light with a specific polarization state, and the polarized light can be utilized by the liquid crystal layer through the polarizer between the liquid crystal layer and the backlight to improve the utilization of light.

For example, in the example shown in FIG. 14 , the second polarized light beam 1002 coupled out from the second light coupling out part 242 is converted into the first polarized light beam 1001 ′ after passing through the polarization conversion structure 400 , and the converted first polarized light beam 1001 ′ The first polarized light beam 1001 coupled out from the first light coupling part 241 is emitted to the predetermined area 40 together.

For example, the above-mentioned predetermined area 40 may refer to a certain area between the backlight source and the display panel, but it is not limited thereto, and the predetermined area may be any area located on the light-emitting side of the backlight source.

For example, the light source part 100 in this embodiment may have the same features as the light source part 100 in the embodiment shown in FIG. 1A to FIG. 13 , and details are not repeated here. The waveguide medium 210 in this embodiment may have the same features as the waveguide medium 210 in the embodiments shown in FIGS. 1A to 13 , and details are not described herein again.

For example, in this embodiment, an optical coupling part may be provided, or an optical coupling part may not be provided. For example, the optical coupling part provided in this embodiment may have the same or similar features as the optical coupling part provided in the embodiments shown in FIG. 1A to FIG. 13 , and details are not repeated here.

For example, the light emitted by the light source part 100 may be unpolarized light, and the unpolarized light includes a first polarized light beam 1001 and a second polarized light beam 1002 with different polarization directions. For example, the first polarized light beam 1001 and the second polarized light beam 1002 may be two kinds of linearly polarized light with perpendicular polarization directions, such as S-polarized light and P-polarized light. The embodiment of the present disclosure is not limited thereto, and the first polarized light and the second polarized light may also be two kinds of circularly polarized light or elliptically polarized light with opposite rotation directions. For example, the embodiment of the present disclosure is not limited to the light emitted by the light source part including only two polarization states, and may also include three or more polarization states.

For example, the first polarized light beam 1001 emitted from the first light coupling out part 241 does not change its characteristics during the process of being incident on the predetermined area 40 . For example, the converted first polarized light beam 1001' and the first polarized light beam 1001 in the light emitted from the light source unit 100 have the same characteristics, that is, polarized light with the same polarization state. For example, the polarization direction of the second polarized light beam 1002 emitted from the second light coupling out part 242 is changed by the polarization conversion structure 400 during the process of being incident on the predetermined area 40 .

For example, the embodiment of the present disclosure is not limited to the total reflection propagation of the light entering the optical waveguide element from the light source part in the optical waveguide element. For example, the light emitted by the light source part can also be transmitted in the transflective element in a non-total reflection manner, for example, it can be is propagating in a straight line.

FIG. 15 is a schematic partial structural diagram of a backlight provided according to an example of another embodiment of the present disclosure. As shown in FIG. 15 , the backlight further includes a spectroscopic element 300 configured to perform spectroscopic processing on the light emitted by the light source unit 100 and directed toward the optical waveguide element 200 . For example, the light splitting element 300 may be located between the light source part 100 and the optical waveguide element 200 and configured to divide the light emitted from the light source part 100 to the optical waveguide element 200 into a first polarized light beam 1001 and a second polarized light beam 1002 .

For example, the light source part 100 emits unpolarized light, the beam splitting element 300 includes a polarized beam splitting element 310, and the polarized beam splitting element 310 is configured to reflect one of the first polarized light and the second polarized light, and transmit the first polarized light and the The other of the second polarized lights; the beam splitter element 300 further includes a reflective element 320 configured to reflect one of the first polarized light and the second polarized light.

For example, the polarization splitting element 310 is configured to split the unpolarized light emitted from the light source section 100 toward the optical waveguide element 200 into a first polarized light beam 1001 and a second polarized light beam 1002 before being incident on the optical waveguide element 200 .

For example, as shown in FIG. 15 , the optical waveguide element 200 includes a first sub-element 2001 and a second sub-element 2002 , and the first sub-element 2001 is provided with a first optical coupling-out portion 241 . The above-mentioned first polarized light beam 1001 is configured to enter the first sub-element 2001, and is coupled out to the predetermined area 40 by the first optical coupling part 241, that is, the first polarized light beam 1001 output by the first optical coupling part 241 is directly Output, such as collimated output light. For example, the second polarized light beam 1002 described above is configured to enter the second sub-element 2002 .

For example, as shown in FIG. 15 , the second sub-element 2002 includes a second light out-coupling part 242 , and the polarization conversion structure 400 is configured to convert the second polarized light out-coupled from the second light out-coupling part 242 into the first polarization Light. The first sub-element 2001 includes a light-emitting surface, the first sub-element 2001 and the second sub-element 2002 overlap in a direction perpendicular to the light-emitting surface, and the polarization conversion structure 400 is located between the first sub-element 2001 and the second sub-element 2002; Or the first sub-element 2001 and the second sub-element 2002 do not overlap in the direction perpendicular to the light-emitting surface.

For example, as shown in FIG. 15 , the second sub-element 2002 is provided with a second light coupling-out portion 242 , and the polarization conversion structure 400 is disposed on the light-emitting side of the second light coupling-out portion 242 so that the second light coupling-out portion 242 is The coupled out second polarized light beam 1002 is converted into a first polarized light beam 1001'. For example, if both the first sub-element and the second sub-element shown in FIG. 15 are provided with an optical outcoupling part, they may have the same structure as the sub-optical waveguide element shown in FIG. 9 , or may have different structures.

For example, FIG. 15 schematically shows that the first sub-element and the second sub-element are separate structures, but not limited thereto, the first sub-element and the second sub-element may also be an integrated structure. For example, the first sub-element and the second sub-element may be connected by a connecting portion on a side away from the light source portion, which is not limited in this embodiment of the present disclosure, and may be set according to actual needs. The above-mentioned "the first sub-element and the second sub-element may also be an integrated structure" may mean that the first sub-element and the second sub-element are the same structure made of the same material through a one-step process, or it may refer to the first sub-element and the second sub-element are connected together by fixing means such as bonding.

For example, as shown in FIG. 15 , the first sub-element 2001 includes a light-emitting surface 001, and the first sub-element 2001 and the second sub-element 2002 overlap in a direction perpendicular to the light-emitting surface 001 (ie, the Y direction shown in the figure). And the polarization conversion structure 400 is located between the first sub-element 2001 and the second sub-element 2002 . The above-mentioned overlapping may include complete overlapping and partial overlapping, for example, the orthographic projections of the first sub-element and the second sub-element on a plane parallel to the light exit surface completely overlap or partially overlap. Figure 15 schematically shows that the first sub-element and the second sub-element fully overlap in the Y direction.

For example, as shown in FIG. 15 , when the first sub-element 2001 and the second sub-element 2002 overlap in the Y direction, the converted first polarized light beam 1001 ′ will pass through the first sub-element 2001 and then be emitted to the predetermined area 40 . For example, the converted first polarized light beam 1001' may pass through the first optical coupling-out part 241, or may not pass through the first optical coupling-out part 241, which is not limited in this embodiment of the present disclosure.

In some embodiments of the present disclosure, the first sub-element and the second sub-element are arranged to overlap, which can improve the brightness of the backlight source and improve the uniformity of light.

For example, as shown in FIG. 15 , the polarization beam splitting element 310 is configured to transmit the second polarized beam 1002 to the second sub-element 2002 of the light emitted by the light source part 100 , and to reflect the first polarized beam 1001 to the first sub-element 2002 of the light. Element 2001. The polarized light splitting element in this embodiment may have the same features as the polarized light splitting element shown in FIG. 9 , and details are not described herein again.

For example, as shown in FIG. 15 , the beam splitting element 300 further includes a reflective element 320, which is located on the side of the polarization beam splitting element 310 away from the optical waveguide element 200 and is configured to reflect the first polarized light beam 1001 to the first sub-element in 2001. The reflective element in this embodiment may have the same features as the reflective element shown in FIG. 9 , and details are not described herein again.

For example, as shown in FIG. 15 , the second polarized light is P-polarized and the first polarized light is S-polarized as an example for illustration. As shown in FIG. 15 , the unpolarized light emitted by the light source part 100 has a polarization splitting function after passing through After the polarization beam splitting element 310 is installed, the transmitted light includes P-polarized light, and the reflected light includes S-polarized light (and vice versa). The transmitted P-polarized light enters the second sub-element 2002 , and the reflected S-polarized light is then reflected to the first sub-element 2001 through the reflective element 320 . The S-polarized light and the P-polarized light are output through the optical coupling and output parts in the respective sub-optical waveguide elements. For example, the S-polarized light is directly output through the first optical coupling-out part 241 , and the P-polarized light is output through the second optical coupling-out part 242 . , and then converted into S-polarized light by the polarization conversion element 400, and then outputted by the first sub-element 2001, realizing the conversion of the unpolarized light emitted by the light source into the same polarized light.

For example, the polarization conversion element may be a 1/2 wave plate. The embodiment of the present disclosure is not limited to this, and it only needs to convert the second polarized light into the first polarized light.

For example, as shown in FIG. 15, the first sub-element 2001 can be located on the side of the second sub-element 2002 away from the light source part 100, so that the transmitted second polarized light enters the second sub-element, and the reflected first polarized light enters the second sub-element 2002. a sub-element, but not limited to this. The light source part can also be located between the first sub-element and the second sub-element, or located on the side of the first sub-element away from the second sub-element, and can be set according to actual requirements.

FIG. 16 is an example diagram of the backlight shown in FIG. 15 . As shown in FIG. 16 , the light coupling-out part 240 includes a transflective element array 220, and each transflective element of the transflective element array 220 is configured to reflect a part of the light propagating to the transflective element to a predetermined area, and transmit the other part to the waveguide medium 210 so that it continues to propagate through total reflection. The waveguide medium 210 includes a main surface, the transflective element array 220 includes a plurality of transflective elements 221 arranged along a first direction, the first direction is parallel to the main surface, and the included angle between each transflective element 221 and the main surface is the first included angle , the angle between the light ray propagating through total reflection in the waveguide medium 210 and the main surface is the second angle, and the difference between the first angle and the second angle is not more than 10 degrees. For example, the difference between the first included angle and the second included angle is not more than 5 degrees. For example, the first included angle and the second included angle are equal, that is, the light propagating through total reflection in the waveguide medium 210 is parallel to the transflective element 221, so that the light is reflected only once in each transflective element, such as avoiding the Light rays parallel to the element are transmitted and reflected on it to improve the uniformity of the light and avoid stray light. Of course, the embodiment of the present disclosure is not limited to this, and the angle between the transflective element and the light propagating through total reflection can also be greater than 5 degrees. The scattered light is reflected back to improve the uniformity of the light exiting the optical waveguide element.

For example, as shown in FIG. 16 , the transflective element array 220 in the first light coupling-out portion 241 includes a plurality of first transflective elements 2211 arranged along the first direction, and the transflective elements in the second light coupling-out portion 242 The array 220 includes a plurality of second transflective elements 2212 arranged along the first direction.

For example, as shown in FIG. 16 , when the first polarized light beam 1001 transmitted to the first transflective element 2211 propagates through total reflection, the included angle with the first transflective element 2211 is the third included angle, and is transmitted to the second transflective element 2212 The included angle between the second polarized light beam 1002 and the second transflective element 2212 is the fourth included angle, and the difference between the third included angle and the fourth included angle is not greater than 5 degrees. For example, if the third included angle and the fourth included angle are equal, the angle of the polarized light entering the sub-elements can be adjusted according to the inclination angle of the transflective element in each sub-element. For example, setting the included angles between different sub-elements and the corresponding polarized light to be the same can also facilitate the fabrication of the sub-elements and the adjustment of the angle of incident light.

For example, as shown in FIG. 16, when the total reflection propagation direction of the first polarized light beam 1001 entering the first sub-element 2001 is the same as the total reflection propagation direction of the second polarized light beam 1002 entering the second sub-element 2002, the first The angle between the transflective element 2211 and the second transflective element 2212 may be no greater than 5 degrees. For example, the first transflective element 2211 may be parallel to the second transflective element 2212 to facilitate the fabrication of the optical waveguide element.

For example, as shown in FIG. 16 , the included angles between the first transflective element 2211 and/or the second transflective element 2212 and the first direction are all acute angles, or both are obtuse angles. The direction indicated by the arrow in the X direction shown in FIG. 16 is the first direction and the total reflection propagation direction of the first polarized light beam 1001 entering the first sub-element 2001 and the second polarized light beam entering the second sub-element 2002 The total reflection propagation direction of 1002 is the same, then when the total reflection propagation direction of each polarized light is the same as the first direction, the angle between each transflective element and the first direction is an acute angle; the total reflection propagation direction of each polarized light is the same as the first direction. When the directions are opposite, the included angle between each transflective element and the first direction is an obtuse angle. The included angle between the transflective element and the first direction is related to the total reflection propagation direction of the polarized light.

For example, as shown in FIG. 16, the first transflective element 2211 is configured such that the reflectivity for the first polarized light beam 1001 is greater than the reflectivity for the second polarized light beam 1002, and the transmittance for the second polarized light beam 1002 is greater than that for the first polarized light beam 1002. Transmittance of a polarized light beam 1001.

The arrangement of the transflective elements in the embodiment of the present disclosure may have the same features as the arrangement of the transflective elements in the example shown in FIG. 9 , which will not be repeated here.

For example, as shown in FIG. 16 , the light emitted from the second sub-element 2002 may pass through the transflective element array 220 in the first sub-element 2001, or may not pass through the transflective element array 220 in the first sub-element 2001. The disclosed embodiments are not limited in this regard. For example, when the polarized light emitted from the second sub-element passes through the transflective element array in the first sub-optical waveguide element, the transflective element array in the first sub-element has a higher value for the polarized light emitted from the second sub-element. transmittance.

For example, the embodiments of the present disclosure are not limited to the light out-coupling part being a transflective element array. For example, the light out-coupling part can also be at least one of a surface grating, a volume grating, a blazed grating, a prism, a reflective structure, and a light-exiting mesh point. At least one of reflection, refraction, and diffraction effects will destroy the total reflection condition of the light, allowing the light to exit the optical waveguide element.

For example, FIG. 17 is a schematic diagram of a partial structure of a backlight provided according to another example of another embodiment of the present disclosure. The example shown in FIG. 17 is different from the example shown in FIG. 15 in that the positional relationship between the first sub-element and the second sub-element shown in FIG. 17 is different. As shown in FIG. 17 , the first sub-element 2001 includes a light-emitting surface, and the first sub-element 2001 and the second sub-element 2002 do not overlap in the direction perpendicular to the light-emitting surface (ie, the Y direction) (for example, they may be just in contact, Or there is a certain distance), which can not only reduce the thickness of the backlight source, but also reduce the degree of light intensity weakening at the edge of the optical waveguide element by setting the length of each sub-element to be smaller.

For example, as shown in FIG. 17 , the first sub-element 2001 and the second sub-element 2002 are arranged along the first direction, and the light source part 100 may be located between the first sub-element 2001 and the second sub-element 2002 , but not limited thereto. For example, when the light source part 100 is located between the first sub-element 2001 and the second sub-element 2002, the total reflection propagation directions of the first polarized light beam 1001 and the second polarized light beam 1002 are opposite. The transflective element and the transflective element in the second sub-element 2002 are not parallel. For example, the included angle between one of the two and the first direction is an acute angle, and the included angle between the other and the first direction is an obtuse angle, so as to realize the transflective element. outcoupling of light.

For example, FIG. 18 is a schematic diagram of a partial structure of a backlight provided according to another example of another embodiment of the present disclosure. The example shown in FIG. 18 is different from the example shown in FIG. 15 in that the position of the second optical coupling-out portion is different. As shown in FIG. 18 , the first optical coupling-out part 241 and the second optical coupling-out part 242 are both located in the first sub-element 2001 . In this example, the light incident to the optical waveguide element is all polarized light as an example for description.

For example, as shown in FIG. 18 , the first sub-element 2001 includes a second light coupling-out portion 242 , the first sub-element 2001 includes a light-emitting surface, and the first sub-element 2001 and the second sub-element 2002 intersect in a direction perpendicular to the light-emitting surface. Stacked, the polarization conversion structure 400 is located on the light incident side of the second light coupling out part 242 , the second polarized light entering the second sub-element 2002 propagates through total reflection in the second sub-element and is converted into the first polarization by the polarization conversion structure 400 After the light is emitted, the converted first deflected light is coupled out by the second light coupling out part 242 .

For example, as shown in FIG. 18 , the second sub-element 2002 is provided with a reflective structure 500 , and the second polarized light propagating through total reflection in the second sub-element 2002 enters the second sub-element 2002 after being converted by the polarization conversion structure 400 and reflected by the reflective structure 500 . In a sub-element 2001 , the polarization conversion structure can be arranged in the optical waveguide element 200 or outside the optical waveguide element 200 .

For example, in this example, the coupling method of the first optical coupling-out part 241 to the first polarized beam 1001 and the coupling method of the second optical coupling-out part 242 to the second polarized beam 1002 can be the same as those shown in FIGS. 15-17 . The examples are the same or different. For example, the spectroscopic element 300 in this example may have the same features as the spectroscopic element in the example shown in FIG. 15 , which will not be repeated here. For example, the waveguide medium in the optical waveguide element of this example may have the same characteristics as the waveguide medium in the example shown in FIG. 15 , and details are not described herein again. For example, the first polarized light and the second polarized light in this example may have the same characteristics as the first polarized light and the second polarized light in the example shown in FIG. 15 , and details are not repeated here.

For example, as shown in FIG. 18 , the first sub-element 2001 includes a light-emitting surface, and the first sub-element 2001 and the second sub-element 2002 partially or completely overlap in a direction perpendicular to the light-emitting surface (ie, the Y direction). The polarization conversion structure 400 is located on the light-incident side of the second light coupling-out portion 242 , and the second polarized light beam 1002 entering the second sub-element 2002 is configured to propagate through total reflection in the second sub-element 2002 , and after passing through the polarization conversion structure 400 It is coupled out by the second optical coupling-out part 242 .

In the embodiment of the present disclosure, by setting the second polarized light to propagate through total reflection in the second sub-element, the second polarized light can be made more uniform, for example, the light and dark distribution of the second polarized light can be more uniform. In the embodiment of the present disclosure, the first optical coupling-out part and the second optical coupling-out part are arranged in the same sub-element, which can reduce the manufacturing cost and is easy to implement.

For example, as shown in FIG. 18 , the light-incident side of the first optical coupling-out part 241 is located on the side of the first optical-coupling-out part 241 away from the second optical coupling-out part 242 , and the light-incident side of the second optical coupling-out part 242 is located. It is located on the side of the second light coupling-out portion 242 away from the first light coupling-out portion 241 .

For example, FIG. 18 schematically shows that a space is provided between the first optical coupling-out part 241 and the second optical coupling-out part 242 , but it is not limited to this. There may also be no spacing to prevent dark areas between the exiting two light couplers that do not allow light to appear. For example, the first light coupling-out portion and the second light coupling-out portion may also be disposed in an overlapping manner, so as to improve the uniformity of light output.

For example, FIG. 18 schematically shows that the first sub-element 2001 and the second sub-element 2002 are separate structures, and the polarization conversion structure 400 is located in the second sub-element 2002, but not limited to this, the polarization conversion structure may also be located in the first sub-element 2002. In a sub-element, or between the first sub-element and the second sub-element, or when the first sub-element and the second sub-element are integrated structures, the polarization conversion structure may be located in the first sub-element and the second sub-element , or outside the first sub-element and the second sub-element, the polarization conversion structure can be located on the light-incident side of the second light coupling-out part, that is, the second polarized light propagating in the second sub-element is converted into The first polarized light can be coupled out by the second light coupling out part.

For example, the second sub-element 2002 may include other optical out-coupling parts (for example, the second sub-element and the first sub-element are separate structures), or may not include an optical out-coupling part (for example, the first sub-element and the second sub-element are in separate structures) is an integrated structure), the second sub-element is mainly configured such that the second polarized light propagates in total reflection therein.

For example, FIG. 18 schematically shows that the light incident side of the second optical coupling-out part 242 in the first sub-element 2001 is provided with a third optical coupling-in part 233, and the third optical coupling-in part 233 can be the same as that in the above-mentioned embodiment. The first optical coupling-in part and the second optical coupling-in part have the same characteristics, but are not limited thereto, and the light-incident side of the second optical coupling-out part 242 in the first sub-element 2001 may not be provided with an optical coupling-in part.

For example, the second polarized light can be converted into the first polarized light by only passing through the polarization conversion structure once, for example, the polarization conversion structure can be a 1/2 wave plate. Of course, the embodiment of the present disclosure is not limited thereto, and the second polarized light may also be converted into the first polarized light after passing through the polarization conversion structure twice, for example, the polarization conversion structure may be a quarter wave plate.

For example, as shown in FIG. 18 , the polarization conversion structure 400 is provided in the second sub-element 2002, and the second sub-element 2002 is further provided with a reflective structure 500, which is located on the side of the polarization conversion structure 400 away from the light source part 100, and in the second sub-element 2002. The second polarized light beam 1002 propagating through total reflection in the two sub-elements 2002 is configured to pass through the polarization conversion structure 400 twice, and is reflected once by the reflection structure 500 to enter the first sub-element 2001 .

FIG. 19 is an example diagram of the backlight shown in FIG. 18 . As shown in FIG. 19 , taking the second polarized light beam 1002 as P-polarized light and the first polarized light as S-polarized light as an example, the unpolarized light emitted by the light source part 100 passes through the polarization beam splitting element 310 with the polarization beam splitting function, P-polarized light is transmitted and S-polarized light is reflected (and vice versa). The transmitted P-polarized light enters the second sub-element 2002 through the second optical coupling part 232, propagates through total reflection in the waveguide medium of the second sub-element 2002, and propagates to the reflective structure 500 at the end face, and the reflected light no longer meets the total reflection condition , the reflected light will leave the second sub-element 2002 . The reflective structure 500 here can be regarded as the light coupling-out portion of the second sub-element 2002 . At the same time, the light incident side of the reflection structure 500 is also provided with a polarization conversion structure 400. When the P-polarized light is reflected, it first passes through the polarization conversion structure 400, and the reflected light also passes through the polarization conversion structure 400 again, and then leaves the second polarization conversion structure 400. The sub-element 2002, that is, the P-polarized light after passing through the polarization conversion structure 400 twice, will be converted into S-polarized light. Reflected, transmitted to the second optical coupling-out portion 242 and coupled out from the first sub-element 2001 .

For example, as shown in FIG. 19 , both the first light coupling-out part 241 and the second light coupling-out part 242 include a transflective element array 220 , and each transflective element 221 included in the transflective element array 220 and the light incident on the surface thereof The included angles are approximately equal. For example, the transflective element array 220 in the first light coupling-out portion 241 includes a plurality of first transflective elements 2211 arranged along the first direction, and the transflective element array 220 in the second light coupling-out portion 242 includes a plurality of first transflective elements 2211 arranged along the first direction. A plurality of second transflective elements 2212 arranged in a direction. Since the total reflection propagation direction of the first polarized light beam 1001 incident on the first light coupling out part 241 is opposite to the total reflection propagation direction of the converted first polarized light beam 1001 ′ incident on the second light coupling out part 242 , the first The first transflective element 2211 and the second transflective element 2212 are not parallel, that is, the inclination directions of the two are different. For example, the angle between one of the first transflective element 2211 and the second transflective element 2212 and the first direction is An acute angle, and the other angle with the first direction is an obtuse angle.

For example, FIG. 19 schematically shows that the first sub-element and the second sub-element are at least partially overlapped in the Y direction, but not limited to this, the first sub-element and the second sub-element may also not overlap in the Y direction stack.

For example, FIG. 20 is a schematic partial structure diagram of a backlight provided according to yet another example of another embodiment of the present disclosure. The example shown in FIG. 20 is different from the example shown in FIG. 14 in that the light emitted from the light source unit is unpolarized light when entering the optical waveguide element.

As shown in FIG. 20 , the optical waveguide element 200 includes a first sub-element 2001 and a second sub-element 2002 , the first sub-element 2001 includes the first optical coupling-out portion 241 , and the second sub-element 2002 The second light coupling out part 242 is included. For example, if both the first sub-element and the second sub-element shown in FIG. 20 are provided with an optical outcoupling part, they may have the same structure as the sub-optical waveguide element shown in FIG. 9 , or may have different structures.

As shown in FIG. 20 , the light source part 100 is configured so that the light emitted by the light source part 100 enters the first sub-element 2001 , and the first polarized light in the light is passed by the first light coupling-out part 241 coupled out, the second polarized light in the light is propagated to the polarization conversion structure 400 in the first sub-element 2001 to be converted into the first polarized light; The first polarized light propagates to the second light coupling-out portion 242 in the second sub-element 2002 to be coupled out by the second light coupling-out portion 242 .

For example, the polarization conversion structure is provided between the first sub-element and the second sub-element; or the first sub-element is provided with the polarization conversion structure, and the polarization conversion structure is located in the first sub-element. A light coupling-out part is away from the light incident side of the first sub-element; or, the second sub-element is provided with the polarization conversion structure, and the polarization conversion structure is located at the second light coupling-out the light-incident side of the part.

As shown in FIG. 20 , the optical waveguide element 200 includes a first sub-element 2001 and a second sub-element 2002 . The first sub-element 2001 is provided with a first optical out-coupling part 241 , and the second sub-element 2002 is provided with a second optical out-coupling part 241 . Section 242. The unpolarized light emitted by the light source part 100 is configured to enter the first sub-element 2001, and the first polarized light beam 1001 in the light is coupled out by the first light coupling part 241, and the second polarized light beam 1002 in the light is configured to be in the light. The first sub-element 2001 propagates to the polarization conversion structure 400 to be converted into a first polarized light beam 1001 ′; the first polarized light beam 1001 ′ converted by the polarization conversion structure 400 is configured to propagate in the second sub-element 2002 to the second polarized light beam 1001 ′ The light coupling-out portion 242 is coupled out by the second light coupling-out portion 242 . The first optical out-coupling part can not only have the effect of out-coupling light, but also can split the unpolarized light entered by the light source part. Therefore, in the embodiment of the present disclosure, the optical out-coupling part located in the optical waveguide element can enter the light source part into the light source part. The unpolarized light is polarized and split, and the setting of the splitting device can be omitted to save the volume of the backlight.

For example, in this example, the coupling method of the first optical coupling-out part 241 to the first polarized beam 1001 and the coupling method of the second optical coupling-out part 242 to the second polarized beam 1002 can be the same as those shown in FIGS. 15-17 . The examples are the same or different. For example, the waveguide medium in the optical waveguide element of this example may have the same characteristics as the waveguide medium in the example shown in FIG. 15 , and details are not described herein again. For example, the first polarized light and the second polarized light in this example may have the same characteristics as the first polarized light and the second polarized light in the example shown in FIG. 15 , and details are not repeated here.

For example, as shown in FIG. 20 , the first light coupling-out portion 241 may have a structure with high reflectivity for the first polarized light beam 1001 and high transmittance for the second polarized light beam 1002 . For example, taking the first polarized light as S-polarized light and the second polarized light as P-polarized light as an example, as shown in FIG. , but directly into the first sub-element 2001. At this time, the first optical coupling-out part 240 is an element with high reflectivity for S-polarized light and high transmittance for P-polarized light. With the propagation of light, S The polarized light gradually leaves the first sub-element 2001; the P-polarized light continues to transmit, and after passing through the polarization conversion element 400, it is converted into S-polarized light, and then enters the second sub-element 2002 for transmission, and is coupled by the second optical coupling-out part 242 A second sub-element 2002 is generated.

For example, as shown in FIG. 20 , the first sub-element 2001 includes a light-emitting surface, and the first sub-element 2001 and the second sub-element 2002 at least partially overlap in a direction perpendicular to the light-emitting surface. But not limited to this, the first sub-element and the second sub-element may also be arranged along the total reflection propagation direction of the light, for example, arranged along the X direction. For example, the first sub-element and the second sub-element may not overlap in the direction perpendicular to the light-emitting surface, and the first light coupling part located in the first sub-element may couple out the first polarized light and transmit the second polarized light Light, the second light coupling part located in the second sub-element can couple out the converted first polarized light.

FIG. 21 is an example diagram of the backlight shown in FIG. 20 . As shown in FIG. 21 , the first light coupling-out portion 241 and the second light coupling-out portion 242 both include a transflective element array 220 , and each transflective element 221 included in the transflective element array 220 is sandwiched with light incident on its surface. The angles are roughly equal. For example, the transflective element array 220 in the first light coupling-out portion 241 includes a plurality of first transflective elements 2211 arranged along the first direction, and the transflective element array 220 in the second light coupling-out portion 242 includes a plurality of first transflective elements 2211 arranged along the first direction. A plurality of second transflective elements 2212 arranged in a direction. Since the total reflection propagation direction of the first polarized light beam 1001 incident on the first light coupling out part 241 is opposite to the total reflection propagation direction of the converted first polarized light beam 1001 ′ incident on the second light coupling out part 242 , the first The first transflective element 2211 and the second transflective element 2212 are not parallel, that is, the inclination directions of the two are different. For example, the angle between one of the first transflective element 2211 and the second transflective element 2212 and the first direction is An acute angle, and the other angle with the first direction is an obtuse angle.

The embodiment of the present disclosure is not limited thereto. When the first sub-element and the second sub-element are arranged along the X direction, the total reflection propagation direction of the first polarized light incident on the first light coupling-out portion is the same as that incident on the second light coupling-out portion. If the total reflection propagation direction of the converted first polarized light is the same, the first transflective element and the second transflective element can be roughly parallel, that is, the two have the same inclination direction, for example, the first transflective element and the second transflective element can be roughly parallel. The included angle between the transflective element and the first direction is either an acute angle or an obtuse angle.

For example, the first transflective element 2211 may be an element with high reflectivity for the first polarized light beam 1001 and high transmittance for the second polarized light beam 1002 to realize the splitting of unpolarized light. For example, the second transflective element 2212 may be either a transflective element without polarization selection characteristics, or an element having a relatively high reflectivity for the first polarized light, which is not limited in this embodiment of the present disclosure.

For example, as shown in FIG. 21 , the light emitted from the light source part 100 is configured to propagate through total reflection in at least one of the first sub-element 2001 and the second sub-element 2002 . For example, FIG. 21 schematically shows that the light rays propagate through total reflection in both the first sub-element 2001 and the second sub-element 2002, but it is not limited to this. It is transmitted in the way of non-total internal reflection, such as propagating directly along a straight line, and in turn passes through the transflective output of the transflective element.

For example, the polarization conversion structure 400 may be disposed between the first sub-element 2001 and the second sub-element 2002 . For example, the polarization conversion structure 400 may also be disposed in the first sub-element 2001 on the side of the first light coupling-out portion 241 away from the light source portion 100 . For example, the polarization conversion structure 400 may also be disposed in the second sub-element 2002 on the light incident side of the second light coupling-out portion 242 .

For example, FIG. 21 schematically shows that the first sub-element and the second sub-element are an integrated structure, and the polarization conversion structure is located in the integrated structure, and is located on the light-emitting side of the first optical coupling-out part and the second optical coupling-out section the light-incident side of the part. The embodiment of the present disclosure is not limited thereto, and the polarization conversion structure may also be located at a position other than the first sub-element and the second sub-element, and it is located on the light-emitting side of the first optical coupling-out part and the light-incident side of the second optical coupling-out part, namely Can.

For example, as shown in FIG. 21 , the optical waveguide element 200 further includes a reflective structure 500 on the light incident side of the polarization conversion structure 400 , the reflective structure 500 is configured to change the propagation direction of the second polarized light beam 1002 so that it is incident on the polarized light beam 1002 . conversion structure 400.

For example, the polarization conversion structure 400 may be a 1/2 wave plate. The polarization conversion structure in this example may be the same as the polarization conversion structure in the examples shown in FIG. 18 to FIG. 19 , and details are not described herein again.

Compared with the scheme in which all the light rays emitted by the light source part are transmitted and output through the same waveguide medium, the embodiment of the present disclosure adopts the scheme of dividing the light rays emitted by the light source part into different polarization states and then separately waveguide transmission and output, so that the output light can be The uniformity of light and dark is further improved.

For example, FIG. 22 is a schematic diagram of a partial structure of a backlight provided according to an example of yet another embodiment of the present disclosure. As shown in FIG. 22 , the backlight includes a light source part 100 and an optical waveguide plate 2000. The optical waveguide plate 2000 includes a light homogenizing part 250 and an optical waveguide element 200. The optical waveguide element 200 includes a light exit surface. The light-emitting surfaces are arranged in sequence in the vertical direction, for example, they are arranged in layers. The light source part 100 is configured so that the light emitted from the light source part 100 enters the optical waveguide element 200 after multiple total reflections in the light homogenizing part 250 , and then exits from the light exit surface of the optical waveguide element 200 .

For example, the number of multiple total reflections is not less than 5 times. For example, the number of multiple total reflections may be 5 to 20 times. For example, the number of multiple total reflections may be 6 to 12 times. For example, the number of multiple total reflections may be 6 to 8 times.

For example, the light homogenizing part 250 includes a light entrance end and a light exit end, and the light entrance end and the light exit end are arranged along the extension direction of the light exit surface; the thickness of the light homogenization part 250 in the direction perpendicular to the light exit surface is not greater than that of the optical waveguide element 200 in the arrangement thickness in the direction. Thus, the uniform light portion can be set to have a smaller thickness to increase the number of total reflections of the totally reflected light therein.

For example, the optical waveguide element 200 includes a waveguide medium 210 and an optical outcoupling portion 240 . The optical waveguide element 200 further includes a light homogenizing part 250. The light from the light source part 100 passes through the light homogenizing part 250 and then reaches the light coupling out part 240. The light entering the optical waveguide element 200 is configured to occur 8 to 11 times in the light homogenizing part 250. Total reflection propagation.

For example, the refractive index of the homogenizing portion 250 is greater than the refractive index of the waveguide medium 210 in the optical waveguide element 200 . By adjusting the refractive index of the uniform light portion, the total reflection critical angle of the light in which total reflection occurs can be adjusted. When the total reflection critical angle is small, the number of total reflections can be increased.

For example, the optical waveguide plate 2000 is an integrated structure. For example, the homogenizing portion 250 and the waveguide medium 210 are an integrated structure. For example, the homogenizing part 250 may be located between the light coupling-out part 240 and the light source part 100 . In the embodiments of the present disclosure, by arranging a light homogenizing part on the light incident side of the optical coupling-out part of the waveguide medium, the uniformity of the light before being transmitted to the optical coupling-out part can be improved, that is, the light is homogenized and then output to obtain light and dark Uniform area light source light.

The above-mentioned "the homogenizing part and the waveguide medium are an integrated structure" can mean that the homogenizing part and the waveguide medium are the same structure made of the same material through a one-step process, or it can also mean that the homogenizing part and the waveguide medium are connected by a fixed method such as bonding together. For example, the homogenizing portion and the waveguide medium may be made of materials with the same refractive index, or materials with different refractive indices, which are not limited in this embodiment of the present disclosure.

For example, the uniform light portion shown in FIG. 22 may also be provided in any of the examples shown in FIGS. 1A to 21 to further improve the uniformity of the light output from the backlight source. For example, the optical coupling-out portion in this embodiment may have the same features as the optical coupling-out portion in any of the examples shown in FIG. 1A to FIG. 21 , and details are not described herein again. For example, the waveguide medium in this embodiment may have the same features as the waveguide medium in any of the examples shown in FIG. 1A to FIG. 21 , and details are not described herein again. For example, the light source part in this embodiment may have the same features as the light source part in any of the examples shown in FIG. 1A to FIG. 21 , and details are not repeated here.

For example, as shown in FIG. 22 , the length of the homogenizing portion 250 along the X direction may not be less than the length along the X direction of the transflective element array serving as the light coupling out portion 240 . The embodiment of the present disclosure is not limited thereto, and the length of the uniform light portion 250 along the X direction may be 1/3 to 2/3 of the length of the transflective element array serving as the light coupling out portion 240 along the X direction.

For example, FIG. 23 is a schematic cross-sectional structure diagram of the backlight shown in FIG. 22 . As shown in FIG. 23 , in this embodiment, an optical coupling part 230 may be provided, or an optical coupling part may not be provided. For example, as shown in FIG. 23 , the optical coupling part 230 provided in this embodiment may have the same features as the optical coupling part provided in any of the examples shown in FIG. 1A to FIG. 21 , and details are not repeated here.

For example, as shown in FIG. 23 , the homogenizing portion 250 may be disposed between the light coupling portion 230 and the light coupling out portion 240 of the optical waveguide element 200 , or may be disposed between the light coupling portion and the light source portion. There is no restriction on this.

For example, as shown in FIG. 23, the light emitted by the light source part 100 first enters the homogenizing part 250 through the optical coupling part 230, and is transmitted in the homogenizing part 250 and gradually homogenized; the homogenized light beam then passes through the optical coupling out part ( For example, a transflective element array) 240 is coupled out, for example, converted into a collimated and parallel light beam.

For example, as shown in FIG. 23 , the light homogenizing part 250 can totally reflect the light entering it for many times, for example, 8 to 11 times, so as to make the light beam distribution uniform, and then realize the effect of uniform light. The light after the homogenization continues to be transmitted to the optical coupling-out part 240 along the total reflection path, and is converted into collimated light through the transmission and reflection of the optical coupling-out part 240 to form a collimated parallel light with uniform brightness and darkness. Therefore, the homogenizing part needs to be arranged before the light coupling-out part.

For example, as shown in FIG. 22 and FIG. 23 , the light coupling-out part 240 includes a plurality of light-coupling-out sub-sections 2401 arranged along the first direction (ie, the X direction). Orientation arrangement. For example, the homogenizing part 250 and the light coupling-out part 240 are arranged on a plane parallel to the XZ plane.

For example, FIG. 24 is a schematic diagram of a partial structure of a backlight provided according to another example of still another embodiment of the present disclosure. As shown in FIG. 24 , the optical waveguide element 200 includes a light exit surface 001 , the light coupling out part 240 and the waveguide medium 210 overlap the light homogenizing part 250 in a direction perpendicular to the light exit surface 001 , and the waveguide medium 210 and the light homogenizing part 250 overlap. A gap medium 260 is disposed therebetween, and the refractive index of the waveguide medium 240 and the refractive index of the homogenizing portion 250 are both greater than the refractive index of the gap medium 260 . In the embodiment of the present disclosure, by arranging the light coupling out part and the waveguide medium to overlap the light homogenizing part, the area occupied by the light homogenizing part can be saved, thereby increasing the area of the light emitting surface of the backlight source to obtain uniform light from the surface light source.

For example, as shown in FIG. 24 , the homogenizing portion 250 may be located on the side of the light coupling out portion 240 away from the light emitting surface 001 .

For example, the interstitial medium 260 may be air or other solid medium (eg, optical glue) with a refractive index smaller than that of the dodging part 250 and the waveguide medium 210 so that the light transmitted in the dodging part and the waveguide medium satisfies the condition of total reflection.

For example, the gap medium 260 may be a transparent medium or a non-transparent medium, which is not limited in this embodiment of the present disclosure.

For example, as shown in FIG. 24 , the length of the homogenizing portion 250 along the X direction may not be less than the length of the transflective element array serving as the light coupling out portion 240 along the X direction to achieve a better homogenizing effect. Limited to this, the length of the uniform light portion 250 along the X direction may be 1/3 to 2/3 of the length of the transflective element array serving as the light coupling out portion 240 along the X direction.

For example, as shown in FIG. 24 , a connecting portion 270 is further provided between the optical waveguide element 200 and the light homogenizing portion 250 , and the connecting portion 270 connects the light incident end of the optical waveguide element 200 and the light outgoing end of the light homogenizing portion 250 , so that the The light of the homogenizing portion 250 enters the optical waveguide element 200 through the connecting portion 270 .

For example, as shown in FIG. 24 , the connecting portion 270 includes a light-adjusting portion 271 configured to destroy the total reflection condition of total reflection of the propagating light in the light-distributing portion 250 , so that the light transmitted in the light-distributing portion 250 Access to the optical waveguide element 200 is possible.

For example, as shown in FIG. 24 , the connecting portion 270 further includes a reflective surface 272 configured to reflect the light in the homogenizing portion 250 into the optical waveguide element 200 . In this embodiment of the present disclosure, the connecting portion may include at least one of a light-adjusting portion and a reflective surface. FIG. 24 schematically shows that the connecting portion includes a light-adjusting portion and a reflecting surface, but is not limited thereto, and the connecting portion may only include a light-adjusting portion and a reflecting surface. The light part, or the connecting part, includes only the reflective surface.

For example, the above-mentioned connecting portion 270 is further disposed between the waveguide medium 210 and the homogenizing portion 250. The connecting portion 270 connects the waveguide medium 240 and the end of the homogenizing portion 250 away from the light incident side of the homogenizing portion 250, so that the homogenizing portion 250 is The light of 250 enters the waveguide medium 210 from the connection part 270 . For example, the connection part 270 is located on the side of the gap medium 260 away from the light source part 100 . For example, the light source part 100 and the connection part 270 are located on both sides of the gap medium 260 in the X direction.

For example, as shown in FIG. 24 , the connecting portion 270 is located on the side away from the light incident side of the light-diffusing portion 250 . For example, the connection part 270 and the light source part 100 are respectively located on both sides of the uniform light part 250 . For example, the connection part 270 and the light source part 100 are located on both sides of the waveguide medium 210, respectively. For example, the connecting portion 270 is located on the light-emitting side of the light-diffusing portion 250 and on the light-incident side of the waveguide medium 210 .

For example, as shown in FIG. 24 , the connecting portion 270 includes a light-adjusting portion 271 configured to destroy the total reflection condition of total reflection of the propagating light in the light-distributing portion 250 , so that the light transmitted in the light-distributing portion 250 The waveguide medium 210 may be entered.

For example, the dimming part 271 can be an optical element with a different refractive index from the waveguide medium 210, such as optical glue, which destroys the condition of total reflection and allows the light to enter the light outcoupling part (for example, a transparent part) located on the side of the homogenizing part 250 facing the display panel. anti-element array).

For example, the dimming part 271 can be used as both the light out-coupling part of the homogenizing part 250 and the light-coupling part of the waveguide medium, or only the light-coupling part of the homogenizing part 250, or only the light-coupling part of the waveguide medium, This embodiment of the present disclosure does not limit this.

For example, as shown in FIG. 24 , the connection part 270 further includes a reflection surface 272 , and the reflection surface 272 is configured to reflect the light emitted from the light homogenizing part 250 toward the waveguide medium 210 .

For example, as shown in FIG. 24, the light entering the homogenizing part 250 is transmitted along the total reflection path in the homogenizing part 250, and is transmitted to the dimming part 271. The dimming part 271 will destroy the total reflection condition of the light, so the light will continue The reflected light is transmitted to the reflective surface 272 and reflected, and the reflected light is transmitted to the light coupler 340 (eg, a transflective element array), and then coupled out through the light coupler 340 , for example, converted into collimated and parallel light.

For example, as shown in FIGS. 22-24 , an embodiment of the present disclosure further provides a light source device, the light source device includes an optical waveguide plate 2000 and a light source part 100 , and the optical waveguide plate 2000 includes a light homogenizing part 250 and an optical waveguide element 200 . The element 250 includes a light emitting surface, and the light homogenizing portion 250 and the optical waveguide element 200 are arranged in sequence in a direction perpendicular to the light emitting surface; The optical waveguide element 200 is then emitted from the light-emitting surface of the optical waveguide element 200 . The light source device can be the backlight in the above-mentioned embodiments, and is applied to the display device together with the display panel, but is not limited thereto, and can also be applied to other devices in combination with other structures.

For example, the display panel provided by the embodiment of the present disclosure may be a liquid crystal display panel, such as a transmissive liquid crystal display panel or a reflective liquid crystal display panel, which can form an image in cooperation with light provided by a backlight source. For example, after the light provided by the backlight passes through a liquid crystal display panel (eg, a liquid crystal screen), it is converted into image light. The embodiment of the present disclosure is not limited to this, and the display panel may also be an electro-wetting screen or a liquid crystal display element on silicon, etc. No matter which type of display panel can be used with the backlight provided by the embodiment of the present disclosure, a display with uniform light and lightness can be formed. device.

For example, FIG. 25 is a schematic diagram of a partial structure of a display device provided according to an example of yet another embodiment of the present disclosure. As shown in FIG. 25 , the display device further includes a light diffusing element 30 located between the optical waveguide element 200 and the display panel 10 . The light diffusing element 30 is configured to diffuse the light emitted from the optical waveguide element 200 , that is, a light diffusing element 30 is configured to diffuse the light beam passing through the light diffusing element 20 . The backlight source in the embodiment of the present disclosure may be the backlight source shown in any of the examples in FIGS. 1A to 24 .

For example, the light diffusing element 30 may also be disposed on the light emitting side of the display panel 10 to diffuse the image light emitted by the display panel 10 .

For example, FIG. 25 schematically shows that the number of light diffusing elements is one, but it is not limited to this, and there may be more than one, and they are arranged at intervals to further improve the dispersion effect of the light beam. The embodiment of the present disclosure schematically shows that the light diffusing element is located on the back side of the display panel, but is not limited thereto, and may also be located on the display surface side of the display panel. For example, the light diffusing element may be attached to the surface of the display surface of the display panel.

For example, the light diffusing element 30 is configured to diffuse the light beam passing through the light diffusing element 30 without changing the optical axis of the light beam. The above-mentioned "optical axis" refers to the center line of the light beam.

For example, after passing through the light diffusing element 30 , the incident light beam will be diffused into a light spot with a specific size and shape along the propagation direction, and the energy distribution is uniform. Precise control. The above-mentioned specific shapes may include, but are not limited to, linear, circular, oval, square, and rectangular.

For example, the light diffusing element 30 may not distinguish the front and back. For example, the propagation angle and spot size of the diffused beam determine the brightness and visible area of the final image. The smaller the diffusion angle, the higher the imaging brightness and the smaller the visible area; and vice versa.

For example, the light diffusing element 30 includes at least one of a diffractive optical element and a scattering optical element.

For example, the light diffusing element 30 can be a scattering optical element with low cost, such as a light homogenizer, a diffuser, etc. When the light beam passes through the scattering optical element such as the light homogenizer, scattering occurs, and a small amount of diffraction also occurs, but the scattering The main function is that the light beam will form a larger spot after passing through the scattering optical element.

For example, the light diffusing element 30 may also be a diffractive optical element (Diffractive Optical Elements, DOE) that can control the diffusing effect more precisely, such as a beam shaping sheet (Beam Shaper). For example, diffractive optical elements play the role of beam expansion through diffraction by designing specific microstructures on the surface. The light spot is small, and the size and shape of the light spot are controllable.

For example, FIG. 26 is a partial structural schematic diagram of a display device provided according to another example of yet another embodiment of the present disclosure. As shown in FIG. 26 , the display device further includes a light condensing element 40 located between the optical waveguide element 200 and the light diffusing element 30 and configured to condense the light emitted from the optical waveguide element 200 to the display panel 10 . The backlight source in the embodiment of the present disclosure may be the backlight source shown in any of the examples in FIG. 1A to FIG. 24 .

For example, as shown in FIG. 26 , the light condensing element 40 is configured to control the direction of the collimated light emitted from the optical waveguide element 200 , and gather the light to a predetermined range, which can further gather the light and improve the utilization rate of the light. The above predetermined range can be a point, such as the focal point of a convex lens, or a small area. The purpose of setting the light converging element is to uniformly adjust the direction of the collimated light output by the optical waveguide element to the predetermined range, so as to improve the utilization rate of light. .

For example, the light converging element 40 may be a lens or a lens combination, such as at least one lens, such as a convex lens, a Fresnel lens, or a lens combination, etc. A convex lens is used as an example for schematic illustration in FIG. 26 .

For example, as shown in FIG. 26 , the light condensing element 40 can condense the collimated light output by the optical waveguide element 200 to a certain range, and the light diffusing element 30 can diffuse the condensed light. The embodiments of the present disclosure provide high light efficiency while expanding the visible range through the cooperation of the light condensing element and the light diffusing element.

For example, as shown in FIG. 26 , in the embodiment of the present disclosure, the light condensing element 40 can focus and orient almost all the light rays, so that the light rays can reach the user's eye box area 003 , so the collimated light beam output by the optical waveguide element 200 is easy to control In order to achieve convenient adjustment of the direction of the light. For example, the area where the observer needs to view the image can be preset according to actual needs, namely the eyebox area (eyebox) 003, the eyebox area 003 refers to the area where the observer's eyes are located and where the image displayed by the display device can be seen, such as It can be a planar area or a three-dimensional area.

For example, as shown in FIG. 26 , the light emitted by the light source part 100 is converted into a uniformly emitted collimated light through the optical waveguide element 200 . After passing through the light condensing element 40 , the collimated light will be collected and fall into the center of the eye box area 003 . The light is further diffused by the light diffusing element 30, and the diffused light beam can cover the eye box area 003, for example, just cover the eye box area 003, achieving high light efficiency without affecting normal observation. The embodiment of the present disclosure is not limited to this, the diffused light beam may also be larger than the eye box area, at least completely covering the eye box; When the light efficiency of the display device is the highest.

For example, FIG. 27 is a schematic partial structural diagram of a display device provided according to another example of yet another embodiment of the present disclosure. The example shown in FIG. 27 differs from the example shown in FIG. 26 in the positional relationship between the light condensing element and the optical waveguide element. As shown in FIG. 27 , the light condensing element 40 and the optical waveguide element 200 have a one-piece structure. In the embodiments of the present disclosure, by arranging the light condensing element and the optical waveguide element in an integrated structure, not only the thickness of the display device can be reduced to facilitate installation, but also light can be prevented from penetrating between the air and the optical waveguide element and/or the light condensing element. Unnecessary reflections on the interface can reduce or avoid wasted light effects.

For example, as shown in FIG. 27 , a transparent medium layer 50 is disposed between the light-converging element 40 and the optical waveguide element 200 , and the refractive index of the transparent medium layer 50 is smaller than that of the optical waveguide element 200 so as to satisfy the requirement of transmission in the waveguide medium. Total reflection of light. For example, the thickness of the transparent medium layer may be small enough to satisfy the propagation condition of total reflection when light propagates in the waveguide medium.

For example, the transparent medium layer 50 can be a medium with high transmittance such as transparent optical glue, which can not only realize the bonding of the light condensing element and the optical waveguide element, but also improve the transmittance of light.

For example, the light converging element 40 and the optical waveguide element 200 may be made of the same material, or may be made of different materials, which are not limited in this embodiment of the present disclosure.

For example, FIG. 28 is a partial structural schematic diagram of a display device provided according to another example of still another embodiment of the present disclosure. The light conversion device can be applied to a display device, in which the light emitted from the backlight is unpolarized light, or the light emitted by the light source part toward the optical waveguide element is unpolarized light, and the display panel is configured to utilize the first A polarized light or a second polarized light generates image light. The backlight source here may be the backlight source that satisfies this condition in the above-mentioned embodiments. The "unpolarized light" here means that the light emitted by the light source can have multiple polarization characteristics at the same time but does not exhibit a unique polarization characteristic. That is, the non-polarized light emitted by the light source part can be decomposed into two mutually perpendicular polarized light rays. The polarized light that can be used by the display panel here may refer to the polarized light that can be incident inside the display panel, or may refer to the polarized light required when the display panel forms image light of a specific polarization state, and the like.

For example, the light conversion device may be provided in multiple locations, eg, configured to recover light emitted by the light source portion and send the recovered light into the optical waveguide element, and/or recover light exiting the optical waveguide element and send the recovered light to the optical waveguide element. into the display panel.

For example, as shown in FIG. 28 , the liquid crystal display panel 10 may include an array substrate (not shown), an opposite substrate (not shown), and a liquid crystal layer (not shown) between the array substrate and the opposite substrate. For example, the liquid crystal display panel further includes a first polarizing layer 10-1 disposed on a side of the array substrate away from the opposite substrate and a second polarizing layer 10-2 disposed on a side of the opposite substrate away from the array substrate. For example, the backlight source 20 is configured to provide backlight to the liquid crystal display panel 10 , and the backlight is converted into image light after passing through the liquid crystal display panel 10 .

For example, the polarization axis direction of the first polarizing layer 10-1 and the polarization axis direction of the second polarizing layer 10-2 are perpendicular to each other, but not limited thereto. For example, the first polarizing layer 10-1 may pass the first linearly polarized light, and the second polarizing layer 10-2 may pass the second linearly polarized light, but not limited thereto. For example, the polarization direction of the first linearly polarized light is perpendicular to the polarization direction of the second linearly polarized light.

For example, only light with a specific polarization state can pass through the first polarizing layer 10-1 between the liquid crystal layer and the backlight source 20 to be incident into the liquid crystal display panel, and be used for imaging. For example, when the light emitted by the backlight source 20 is non-polarized light, at most 50% of the light emitted by the backlight source 20 can be utilized by the image generating unit, and the rest of the light will be wasted or absorbed by the liquid crystal layer to generate heat. However, in the embodiment of the present disclosure, by arranging a light conversion device on the light incident side of the display panel, almost all of the unpolarized light emitted by the backlight can be converted into light with a specific polarization state that can be utilized by the display panel, thereby effectively improving the output of the backlight. utilization of light.

For example, as shown in FIG. 28 , the light conversion device 50 is located on the side of the display panel 10 facing the optical waveguide element 200 . 28 schematically shows that the light conversion device 50 is located between the light condensing element 40 and the optical waveguide element 200, but not limited to this, the light conversion device can also be located between the optical waveguide element and the light source part, the light condensing element and the light diffusing element. Between the light diffusing element and the display panel, the light conversion device may be located on the light incident side of the display panel so that the incident light on the display panel is of a specific polarization state.

For example, the light conversion device includes a beam splitting element 51 , a direction changing element 52 , and a polarization converting element 53 . For example, the beam splitting element 51 is configured to split the light incident on the beam splitting element 51 into a first polarized light beam 101 and a second polarized light beam 102 with different polarization states, and the first polarized light beam 101 is configured to be directed toward the display panel 10 , the second polarized light beam 102 is directed towards the direction changing element 52 . The direction changing element 52 is configured to change the propagation direction of the light incident to the direction changing element 52 so as to be directed toward the display panel 10 . The polarization conversion element 53 is configured to convert the polarized light that cannot be utilized by the display panel 10 in the first polarized light beam 101 and the second polarized light beam 102 into polarized light that can be utilized by the display panel 10 before reaching the display panel 10 .

For example, as shown in FIG. 28 , both the first polarized light beam 101 and the second polarized light beam 102 are linearly polarized light. For example, the first polarizing layer 10-1 included in the display panel 10 is located on the side of the display panel 10 close to the light source part 100, and the polarization axis of the first polarizing layer 10-1 is parallel to the first polarized light beam 101 or the second polarized light beam 102 The polarization conversion element 53 is configured to convert the polarized light whose polarization direction is not parallel to the polarization axis in the first polarized light beam 101 and the second polarized light beam 102 into a polarization whose polarization direction is parallel to the polarization axis before reaching the display panel 10 Light. FIG. 28 schematically shows that the polarization direction of the second polarized light beam 102 is parallel to the polarization axis of the first polarizing layer 10-1, but it is not limited to this, and the polarization direction of the first polarized light can also be parallel to the first polarizing layer. Polarization axis.

For example, as shown in FIG. 28 , the backlight source 20 emits unpolarized light, the display panel 10 can use S-polarized light (the second polarized light beam 102 ), and the beam splitting element 51 reflects the S-polarized light and transmits the P-polarized light (the first polarized light beam 102 ). 101), the direction changing element 52 can reflect S-polarized light. The S-polarized light in the light emitted by the backlight source 20 is reflected by the beam splitting element 51, the reflected S-polarized light is reflected by the direction changing element 52 and then exits to the display panel 10, and the P-polarized light in the light emitted by the backlight source 20 is divided. The beam element 51 transmits, and after transmission, passes through the polarization conversion element 53 and is converted into S-polarized light, so that the unpolarized light emitted by the backlight can be converted into S-polarized light usable by the display panel.

For example, the beam splitting element 51 may have the function of transmitting light of one characteristic and reflecting light of another characteristic, for example, the beam splitting element 51 may have the characteristic of transmitting light of one polarization state and reflecting light of another polarization state , the beam splitting element can realize beam splitting by utilizing the above-mentioned transflective characteristics.

For example, the beam splitting element 51 may be a transflective film, which achieves beam splitting by transmitting part of the light and reflecting another part of the light. For example, the transflective film can transmit the first polarized light beam 101 in the light emitted by the backlight 20 and reflect the second polarized light beam 102 in the light emitted by the backlight 20 .

For example, the transflective film can be an optical film with polarized transflective function, specifically, an optical film that can split unpolarized light into two mutually perpendicularly polarized lights through transmission and reflection; the above-mentioned optical film can be composed of multiple layers The film layers with different refractive indices are combined in a certain stacking order, and the thickness of each film layer is about 10-1000nm; the material of the film layer can be selected from inorganic dielectric materials, such as metal oxides and metal nitrides; Polymeric materials such as polypropylene, polyvinyl chloride or polyethylene can also be selected.

For example, the beam splitting element 51 may be an element formed by coating or sticking a film on a transparent substrate. For example, the beam splitting element 51 may be a transflective film with the characteristics of reflecting S-polarized light and transmitting P-polarized light, such as a reflective polarized brightness enhancement film (Dual Brightness Enhance Film, DBEF) or a prism film ( Brightness Enhancement Film, BEF) and so on. The embodiments of the present disclosure are not limited thereto, for example, the beam splitting element may also be an integrated element.

For example, the direction changing element 52 is configured to reflect the second polarized light beam 102 incident on the direction changing element 52 to the display panel 10 .

For example, the direction changing element 52 may be a reflective element for reflecting the second polarized light beam 102 emitted from the beam splitting element 51 to the display panel 10 . Since the polarization axis of the polarizing layer 210 of the display panel 10 is parallel to the polarization direction of the second polarized light beam 102 , the second polarized light beam 102 emitted from the direction changing element 52 to the display panel 10 can be directly utilized by the display panel 10 .

For example, the direction changing element 52 can be a common reflective plate, such as a metal or glass reflective plate; it can also be a reflective film with the characteristic of reflecting S-polarized light plated or pasted on the substrate. For example, the direction changing element 52 may have a transflective property, which is the same as that of the transflective film included in the beam splitting element 51 , that is, the property of reflecting S-polarized light and transmitting P-polarized light. This embodiment of the present disclosure does not limit this, as long as the direction changing element 52 can reflect the S-polarized light.

For example, the polarization conversion element 53 can be a phase retardation film. By rotating the polarization direction of the first polarized light beam 101 incident thereon by 90 degrees, the light emitted from the phase retardation film to the display panel 10 can be utilized by the display panel 10 . of the second polarized light beam 102 . For example, the polarization conversion element 53 may be a 1/2 wave plate.

For example, the polarization conversion element may be disposed in close contact with the beam splitting element. For example, a transparent substrate may be arranged between the beam splitting element and the polarization conversion element, and the beam splitting element and the polarization conversion element are respectively attached to two surfaces of the transparent substrate opposite to each other for convenient arrangement. The embodiments of the present disclosure are not limited to this, for example, the beam splitting element may also be directly attached to the surface of the polarization conversion element to achieve lightness and thinness of the image source.

For example, as shown in FIG. 28 , the polarization converting element 53 is located on the side of the beam splitting element 51 away from the direction changing element 50 .

For example, FIG. 28 schematically shows that the beam splitting element and the direction changing element are nearly parallel, and the finally emitted and recovered light rays are nearly parallel collimated rays. But it is not limited to this, if the beam splitting element and the direction changing element are not parallel, the emitted light can be in a diffused or concentrated state, which is suitable for some special application scenarios.

For example, FIG. 29 is a schematic diagram of a light conversion device in a display device provided according to another example of yet another embodiment of the present disclosure. The difference between the light conversion device shown in FIG. 29 and the light conversion device shown in FIG. 28 is that the position of the polarization conversion element and the light of the polarization state that can be used by the display panel are different. The features of the element 52 and the polarization conversion element 53 may be the same as those of the respective elements shown in FIG. 28 , and details are not repeated here.

For example, FIG. 30 is a schematic diagram of a light conversion device in a display device provided according to yet another example of yet another embodiment of the present disclosure. The difference between the light conversion device shown in FIG. 30 and the light conversion device shown in FIG. 28 is that the position of the polarization conversion element and the light of the polarization state that can be used by the display panel are different, and the polarized light reflected by the direction changing element 52 is different. The characteristics of the beam splitting element 51 and the polarization conversion element 53 in the conversion device may be the same as those of the elements shown in FIG. 28 , and details are not repeated here.

For example, FIG. 31 is a schematic diagram of a light conversion device in a display device provided according to yet another example of yet another embodiment of the present disclosure. The difference between the light conversion device shown in FIG. 31 and the light conversion device shown in FIG. 29 is that the light in this example passes through the polarization conversion element 53 twice, while the light in the example shown in FIG. 29 passes through the polarization conversion element 53 only once , and the polarized light reflected by the direction changing element 52 is different.

For example, as shown in FIG. 31, the polarization conversion element 53 is located between the direction change element 52 and the beam splitting element 51, and is configured to convert the second polarized light beam 102 reflected from the beam splitter element 51 toward the direction change element 52 into a second polarized light beam 102 Three polarized lights 103 . The third polarized light 103 is reflected by the direction changing element 52 and converted into the first polarized light beam 101 after passing through the polarization conversion element 53 , and the converted first polarized light beam 101 is directed toward the display panel 10 .

For example, the polarization conversion element 53 can be a phase retardation film, such as a quarter-wave plate, and can convert the second polarized light beam 102, such as linearly polarized light, incident thereon into a third polarized light 103, such as circularly polarized light Or elliptically polarized light, so that the polarized light incident on the direction changing element 52 after passing through the retardation film is no longer linearly polarized light. The third polarized light 103 incident on the direction changing element 52 is changed in the direction of propagation by the direction changing element 52 to propagate toward the display panel 10, and the third polarized light 103 before reaching the display panel 10 passes through the polarization converting element 53 again to be converted into The first polarized light beam 101 that can be utilized by the display panel 10 .

For example, the characteristics of the beam splitting element 51 and the direction changing element 52 in the light conversion device in this example may be the same as those of the corresponding elements shown in FIG. 28 , and details are not repeated here.

FIG. 32 is a partial structural schematic diagram of a head-up display provided according to another embodiment of the present disclosure. FIG. 32 schematically shows that the head-up display includes the display device shown in FIG. 26 , but is not limited thereto, and may also include the display device shown in any example of FIG. 25 or FIG. 27 to FIG. 31 , to which the embodiments of the present disclosure No restrictions apply.

As shown in FIG. 32 , the head-up display further includes a reflective imaging part 60 on the light-emitting side of the display panel 10 . The reflective imaging part 60 is configured to reflect the light emitted from the display panel 10 to the eye box area 003 and transmit ambient light. The user located in the eye box area 003 can view the image 004 of the display panel 10 reflected by the reflective imaging part 60 and the environmental scene located on the side of the reflective imaging part 60 away from the eye box area 003 . For example, the image light emitted by the display panel 10 is incident on the reflective imaging part 60, and the light reflected by the reflective imaging part 60 is incident on the user, for example, the eye box area 003 where the driver's eyes are located, and the user can observe the image formed in the reflective imaging part, for example The virtual image on the outside does not affect the user's observation of the external environment.

For example, the above-mentioned eye box area 003 refers to a plane area where the user's eyes are located and the image displayed by the head-up display can be seen. For example, when the user's eyes deviate from the center of the eye box area by a certain distance, such as moving up and down, left and right for a certain distance, the user's eyes are still in the eye box area, and the user can still see the image displayed by the head-up display.

For example, as shown in FIG. 32 , the reflective imaging part 60 may be a windshield (eg, windshield) or an imaging window of a motor vehicle, corresponding to a windshield head-up display (W-HUD) and a combined head-up display (C-HUD), respectively. ).

For example, as shown in FIG. 32 , the reflective imaging part 60 can be a flat plate, forming a virtual image through specular reflection; it can also be a curved surface, such as a windshield or a transparent imaging plate with curvature, which can provide farther imaging distance.

33 is an exemplary block diagram of a transportation device provided according to another embodiment of the present disclosure. As shown in FIG. 33, the transportation device includes a heads-up display provided by at least one embodiment of the present disclosure. The front window of the traffic device (eg, the front windshield) is multiplexed as the reflective imaging portion 60 of the head-up display.

For example, the transportation equipment may be various suitable vehicles, for example, may include various types of land transportation equipment such as automobiles, or may be water transportation equipment such as boats, or may be air transportation equipment such as airplanes. front window and transmits the image onto the front window through the on-board display system.

It should be noted that, in the drawings for describing the embodiments of the present disclosure, the thicknesses of layers or regions are exaggerated or reduced for clarity, ie, the drawings are not drawn to actual scale.

Although the present disclosure has been described in detail above with general descriptions and specific implementations, some modifications or improvements can be made on the basis of the embodiments of the present disclosure, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present disclosure fall within the scope of the claimed protection of the present disclosure.

The following points need to be noted:

(1) In the drawings of the embodiments of the present disclosure, only the structures involved in the embodiments of the present disclosure are involved, and other structures may refer to general designs.

(2) Features in the same embodiment and different embodiments of the present disclosure may be combined with each other without conflict.

The above descriptions are only exemplary embodiments of the present disclosure, and are not intended to limit the protection scope of the present disclosure, which is determined by the appended claims.

Claims (22)

1. A display device, comprising:

a display panel having a display surface and a back side opposite the display surface; and

a backlight positioned at a back side of the display panel,

the backlight source comprises an optical waveguide plate, the optical waveguide plate comprises a light homogenizing part and an optical waveguide element, the optical waveguide element comprises a light emitting surface, and the light homogenizing part and the optical waveguide element are sequentially arranged in a direction vertical to the light emitting surface;

the backlight source further comprises a light source part, and the light source part is configured to enable the light emitted by the light source part to enter the optical waveguide element after being subjected to total reflection in the light homogenizing part for multiple times and then to be emitted from the light emitting surface of the optical waveguide element.

2. The display device according to claim 1, wherein the number of times of the plurality of total reflections is not less than 5 times.

3. The display device according to claim 1, wherein the light uniformizing part includes a light incident end and a light exit end, the light incident end and the light exit end being arranged along an extending direction of the light exit surface; the thickness of the uniform light portion in a direction perpendicular to the light exit surface is not greater than the thickness of the optical waveguide elements in the arrangement direction.

4. The display device according to claim 1, wherein a refractive index of the uniform light portion is larger than a refractive index of a waveguide medium in the optical waveguide element.

5. The display device of claim 1, wherein the optical waveguide plate is a unitary structure.

6. A display device according to claim 1, wherein a gap medium is provided between the optical waveguide element and the uniform light portion in a direction perpendicular to the light exit surface, and a refractive index of the waveguide medium and a refractive index of the uniform light portion in the optical waveguide element are both larger than a refractive index of the gap medium.

7. The display device according to claim 6, wherein a connecting portion is further provided between the optical waveguide element and the backlight portion, the connecting portion connecting a light entrance end of the optical waveguide element and a light exit end of the backlight portion so that light from the backlight portion enters the optical waveguide element through the connecting portion.

8. The display device according to claim 7, wherein the connection portion includes a light adjusting portion configured to break a total reflection condition of a light propagated by total reflection in the light unifying portion so that the light propagated in the light unifying portion can enter the optical waveguide element.

9. The display device according to claim 7 or 8, wherein the connecting portion further comprises a reflective surface configured to reflect light rays in the dodging portion into the optical waveguide element.

10. A display device according to claim 1, wherein the optical waveguide element comprises a light outcoupling portion comprising a plurality of light outcoupling subsections arranged in an extending direction of the light outcoupling surface.

11. A display device according to claim 10, wherein the optical waveguide element further comprises a waveguide medium, the light out-coupling portion comprises an array of transflective elements located in the waveguide medium, each transflective element of the array of transflective elements being configured to reflect a portion of light rays propagating to the transflective element out of the optical waveguide element and to transmit another portion of the light rays.

12. The display device according to claim 11, wherein an included angle between each of the transflective elements and the light emitting surface is a first included angle, and a sum of the first included angle and a critical angle of total reflection of the light beam at the light emitting surface is in a range of 60 ° to 120 °.

13. The display device according to claim 11, wherein the reflectivities of the transflective elements arranged in sequence along the extending direction of the light exit surface in the transflective element array gradually increase or gradually increase regionally in the propagation direction of the light; and/or

The arrangement density of the transflective elements sequentially arranged along the extending direction of the light emergent surface in the transflective element array is gradually increased or gradually increased in a regional manner.

14. The display device of claim 11, wherein the transflective element array includes at least some of the plurality of transflective elements arranged in sequence along a first direction and extending along a second direction that intersects the first direction,

the light source section includes a plurality of sub light sources arranged in the second direction, the plurality of sub light sources being configured to emit light rays entering the at least partially transflective element.

15. The display device of claim 11, wherein at least one transflective element of the array of transflective elements comprises a transflective film, wherein the light rays entering the optical waveguide element comprise first and second light rays having different characteristics, the transflective film being configured to have a greater reflectivity for the first light ray than the second light ray and a greater transmissivity for the second light ray than the first light ray.

16. The display device according to any one of claims 1 to 15, wherein the light emitted from the light source section includes first polarized light and second polarized light having different polarization states, the display panel is configured to generate image light using the first polarized light or the second polarized light,

wherein the display device further comprises a light conversion device comprising a beam splitting element, a direction changing element and a polarization converting element,

the beam splitting element is positioned on one side of the display panel facing the optical waveguide element and is configured to split light incident to the beam splitting element into a first polarized light beam and a second polarized light beam with different polarization states, the first polarized light beam is emitted to the display panel, and the second polarized light beam is emitted to the direction changing element;

the direction change element is configured to change a propagation direction of a light beam incident to the direction change element to be directed to the display panel;

the polarization conversion element is configured to convert polarized light beams of the first and second polarized light beams that cannot be utilized by the display panel into polarized light beams that can be utilized by the display panel before reaching the display panel.

17. The display device according to claim 16, further comprising:

at least one light diffusing element located on at least one of the display surface side and the back side of the display panel and configured to diffuse light exiting at least one of the display panel and the optical waveguide element.

18. The display device according to claim 17, further comprising:

and a light converging element positioned between the light guide element and the display panel and configured to converge the light emitted from the light guide element and then direct the converged light to the at least one light diffusing element.

19. A heads-up display comprising:

the display device of any one of claims 1-18; and

the reflection imaging part is positioned on the light emitting side of the display device and is configured to reflect the light emitted by the display device to the observation area of the head-up display.

20. A transportation device comprising the heads-up display of claim 19.

21. The transit device as defined in claim 20, wherein the reflective imaging portion comprises a windshield of the transit device.

22. A light source device comprising:

the optical waveguide plate comprises a light homogenizing part and an optical waveguide element, the optical waveguide element comprises a light-emitting surface, and the light homogenizing part and the optical waveguide element are sequentially arranged in a direction vertical to the light-emitting surface; and

and a light source unit configured to cause light emitted from the light source unit to enter the optical waveguide element after being totally reflected a plurality of times in the light uniformizing unit and then to exit from the light exit surface of the optical waveguide element.

Images