WO2023011199A1 - Display device module, display device and image display method - Google Patents

Abstract

Disclosed in the embodiments of the present application is a display device module. The display device module may be applied to an augmented reality device, a vehicle-mounted head-up display device, etc. The display device module comprises an optical waveguide, a plurality of first out-coupling grating units and a plurality of second out-coupling grating units, wherein the plurality of first out-coupling grating units and the plurality of second out-coupling grating units are fixed to the optical waveguide in a staggered distribution manner; and the plurality of first out-coupling grating units and the plurality of second out-coupling grating units are respectively used for diffracting light of a first optical characteristic and light of a second optical characteristic in a light beam, and coupling out to human eyes for imaging. The display device module completes differentiated diffraction control by means of providing out-coupling grating units having different functions, so as to realize the decomposition and combination of a large field-of-view angle, the display of different depth images, the display of a color image, etc.

Description

A display device module, display device, and image display method

This application claims the priority of the Chinese patent application submitted to the China Patent Office on July 31, 2021, with the application number 202110877147.9, and the title of the invention is "a display device module, display device, and image display method", the entire content of which is passed References are incorporated in this application.

technical field

The embodiments of the present application relate to the field of optics, and in particular to a display device module, a display device, and an image display method.

Background technique

Augmented reality (augmented reality, AR) near-eye display technology is a wearable display system that enables the human eye to see the real scene outside and the virtual scene generated by the computer through a certain optical system. In the AR system, the computing component analyzes and processes the real scene observed by the user, and then superimposes the generated virtual augmented information on the real scene through the near-eye display technology, realizing the seamless integration of real and virtual scenes, and assisting users to understand Deep, comprehensive cognition of the real world. The core task of AR near-eye display technology is to perform virtual-real superposition, which allows real-world light and virtual image light to pass through at the same time and reach the human eye. Near-eye display technology, one of the core technologies of AR devices, has also become a research hotspot in the industry and academia. Optical see-through near-eye display devices have great potential because they allow users to simultaneously observe real scenes and computer-generated virtual scenes. In order to increase the portability of transmissive near-eye display devices, researchers have introduced free-form surface optics, projection optics, diffractive optics, and optical waveguide technologies to reduce the thickness and weight of near-eye display devices.

At present, diffractive optical waveguide technology is considered to be the most promising technology to achieve ultra-thin near-eye display devices. The display method of diffractive optical waveguide technology combines diffraction technology such as micro-nano holography and waveguide technology. Through the diffraction effect of the diffraction element, the amplitude or phase of the light wave is modulated to control the propagation direction of the light; , usually made of glass or resin) confines the light inside the waveguide and propagates between the diffraction devices in a way of total reflection along a preset direction. Diffraction devices are selective to the angle of incidence of incident light, that is, only light with an angle of incidence within a specific range will be diffracted. Therefore, through reasonable design, the angle of incidence of image light can be diffracted to meet the angle selectivity, while the external The light in the environment does not meet the angle selectivity and directly penetrates the diffraction device, so as to achieve the purpose of superimposing the virtual image with the external scene image in a projection manner.

However, the diffractive element in the existing diffractive optical waveguide technology is usually a large-scale device counted as a whole, and the surface microstructure distribution is continuous. In order to achieve differential diffraction control, the entire diffraction surface needs to be designed and processed differently on the diffraction structure, resulting in increased design complexity and processing difficulty, and some surface defects will affect the diffraction effect of the entire diffraction device, affecting good products rate, leading to high device cost. In order to achieve different diffraction functions, it needs to be prepared by repeated etching or multiple exposure techniques. This method is at the expense of the diffraction efficiency of the diffraction element. As the number of multiplexing increases, the diffraction efficiency decreases.

Contents of the invention

An embodiment of the present application provides a display device module. Different outcoupling grating units are provided, and different outcoupling units diffract incident light with different optical characteristics, so as to realize differential diffraction control.

The first aspect of the embodiments of the present application provides a display device module, which can be applied to AR devices, vehicle-mounted head up display (HUD) devices, and the like. The display device module includes: an optical waveguide, a plurality of first outcoupling grating units and a plurality of second outcoupling grating units, the plurality of first outcoupling grating units are fixed on the optical waveguide, and the plurality of second outcoupling grating units are fixed on the optical waveguide, and a plurality of first outcoupling grating units and a plurality of second outcoupling grating units are alternately distributed; Two outcoupling grating units propagate light beams; multiple first outcoupling grating units are used to diffract the light of the first optical characteristic in the beam and couple out the diffracted light; multiple second outcoupling grating units are used for diffracting the light of the second optical characteristic in the light beam and outcoupling the diffracted light, the first optical characteristic and the second optical characteristic are different.

Wherein, the multiple first outcoupling grating units are different from the multiple second outcoupling grating units, which can be understood as referring to the difference between the light diffracted by the multiple first outcoupling grating units and the light diffracted by the multiple second outcoupling grating units. Light is different. Or it can be understood that the diffraction functions of the multiple first outcoupling grating units are different from those of the multiple second outcoupling grating units, rather than different structures and shapes. It can also be understood that a plurality of first outcoupling grating units diffract light of the first optical characteristic, and do not diffract light of the second optical characteristic; a plurality of second outcoupling grating units act on light of the second optical characteristic Diffraction, the light of the first optical characteristic does not diffract. For example: multiple first outcoupling grating units are used to diffract only the light of the first optical characteristic in the beam and couple it to the human eye for imaging; multiple second outcoupling grating units are used to only diffract the light of the second optical characteristic in the beam Light with optical characteristics is diffracted and coupled out to human eyes for imaging, and the first optical characteristic is different from the second optical characteristic. It can be understood that the "only" here does not limit that the grating unit has only one function, but is used to describe that the first outcoupling grating unit diffracts the light of the first optical characteristic, and does not diffract the light of the second optical characteristic (e.g. transmission).

In addition, the staggered distribution of multiple first outcoupling grating units and multiple second outcoupling grating units can be understood as that two adjacent outcoupling grating units are first outcoupling grating units and second outcoupling grating units respectively. It can also be understood that there is a second outcoupling grating unit between two first outcoupling grating units, and there is a first outcoupling grating unit between two second outcoupling grating units. Of course, it is also possible that every two first outcoupling grating units are adjacent to two second outcoupling grating units. In some cases, this staggered distribution can also be understood as an alternating distribution.

The above-mentioned image engine can also be called an optical machine, a micro-projection optical machine, etc., and the image engine is used to generate light carrying virtual image information, and direct the generated light to the optical waveguide, and then couple out the grating unit (the first coupling The output grating unit and the second output grating unit) diffract the light and couple it to the human eye to form a virtual image corresponding to the virtual image information. The light of the virtual image and the light carrying the real environment information are imaged in human eyes, and then the user can see a fusion image including the virtual image and the real image. Furthermore, the light emitted by the image engine can be a collimated beam or not. If the light emitted by the image engine is not a collimated beam, the collimation function can also be realized by adding a coupling grating to the optical waveguide.

In the embodiment of this application, on the one hand, the display device module completes differential diffraction control by setting out-coupling grating units with different functions, and then realizes, for example: decomposition and merging of large viewing angles, display of images with different depths, color image display, etc. On the other hand, compared with the monolithic grating structure in the prior art, the multiple outcoupling grating units are more flexible, and the etching process is relatively simple, without multiple etching or multiple exposures.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned plurality of first outcoupling grating units are specifically used to perform total diffraction on the light of the first optical characteristic in the light beam and make the total diffracted light Outcoupling: a plurality of second outcoupling grating units, used to perform total diffraction on the light of the second optical characteristic in the light beam and couple out the fully diffracted light.

In this possible implementation, the outcoupling grating unit can be set as a nearly 100% diffraction grating, which can improve the utilization rate of light energy compared with the half-reflection and half-transmission diffraction grating in the prior art.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned first optical characteristic and the second optical characteristic are different, including: the first wavelength of light corresponding to the first optical characteristic and the first wavelength of light corresponding to the second optical characteristic The second wavelength of the light is different; or, the first polarization state of the light corresponding to the first optical characteristic is different from the second polarization state of the light corresponding to the second optical characteristic; or, the first incident angle of the light corresponding to the first optical characteristic The second incident angle of the light corresponding to the second optical characteristic is different.

In this possible implementation, multiple first outcoupling grating units and multiple second outcoupling grating units selectively modulate the light in different roles according to the wavelength, polarization state, and incident angle corresponding to the light beam, which can realize Uniform light output, large field of view, multiple depths, color AR near-eye display, etc.

Optionally, in a possible implementation manner of the first aspect, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are distributed alternately on the same plane.

In this possible implementation, compared with the existing solutions in the prior art, multiple exposures in the same spatial area (volume holographic grating) or overlay diffraction structures (relief grating) are used to achieve different incident angles and incident light wavelengths. , Selective diffraction of incident light of polarization state. Multiple exposure/overlay schemes result in reduced grating diffraction efficiency, which in turn leads to dimming of the image light entering the eye, as well as light leakage from the lens. In this way, the selective diffraction of light is realized through the staggered distribution of the grating units on the plane, and the problem of the decrease of the diffraction efficiency of the grating is reduced.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned multiple first outcoupling grating units and multiple second outcoupling grating units are distributed in multiple outcoupling gratings, and each outcoupling grating includes A part of the first outcoupling grating units among the multiple first outcoupling grating units and a part of the second outcoupling grating units among the multiple second outcoupling grating units, one side of the outcoupling grating and the surface of the optical waveguide away from the human eye In contact, the other side of the outcoupling grating is in contact with the surface of the optical waveguide near the human eye.

In this possible implementation manner, it is ensured that all the light in the light beam emitted by the image engine is diffracted, so as to improve the utilization rate of the light beam.

Optionally, in a possible implementation of the first aspect, multiple first outcoupling grating units and multiple second outcoupling grating units are fixedly embedded inside the optical waveguide respectively, and multiple first outcoupling grating units It is not on the same plane as the plurality of second outcoupling grating units. If the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are not on the same plane, for the beam emitted by the image engine, if the plurality of first outcoupling grating units diffract a part of the light in the beam, then more A second outcoupling grating unit diffracts another part of the light in the light beam.

In this possible implementation manner, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units can jointly diffract all the light in the light beam emitted by the image engine, thereby improving the utilization rate of light energy.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned multiple first outcoupling grating units and multiple second outcoupling grating units are fixed on the surface of the optical waveguide or embedded inside the optical waveguide. Wherein, the surface includes an inner surface (or called an inner wall) or an outer surface (or called an outer wall). The outcoupling grating fixedly embedded in the optical waveguide can be parallel to or not parallel to the plane of the optical waveguide (for example, placed obliquely).

In this possible implementation manner, there are many ways to fix the outcoupling grating unit to the optical waveguide, and differential diffraction control can be flexibly realized according to actual needs.

Optionally, in a possible implementation manner of the first aspect, the incident angle and the outgoing angle of the above-mentioned light of the first characteristic on the plurality of second outcoupling grating units are the same, and the light of the second characteristic The incident angle on the first outcoupling grating unit is the same as the outgoing angle. For example: a plurality of first outcoupling grating units are also used to transmit the light of the second optical characteristic in the light beam, and the angle of the light of the second optical characteristic does not change before and after transmission; the optical waveguide is also used to transmit the light of the second optical characteristic The light with optical characteristics is totally reflected and transmitted to multiple second outcoupling grating units; the multiple second outcoupling grating units are also used to transmit the light with the first optical characteristics in the light beam; the optical waveguide is also used to The light of the first optical feature is totally reflected and transmitted to the plurality of first outcoupling grating units. The "transmission" in this embodiment can be understood as the exit phenomenon of the incident light after passing through the object, which can be understood as non-diffraction. It can be understood that a plurality of first outcoupling grating units diffract the light of the first optical characteristic, and transmit the light of the second optical characteristic (also can be understood as non-diffraction); a plurality of second outcoupling grating units pair The light of the second optical characteristic is diffracted and transmits the light of the first optical characteristic.

In this possible implementation, the light of the first optical characteristic is diffracted by a plurality of first outcoupling grating units, the light of the second optical characteristic is transmitted, and the light of the second optical characteristic is transmitted by the plurality of second outcoupling grating units. The light of the first optical characteristic is diffracted, and the light of the first optical characteristic is transmitted, thereby achieving differential diffraction control between the plurality of first outcoupling grating units and the plurality of second outcoupling grating units.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned multiple first outcoupling grating units adopt the first diopter to diffract the light of the first optical characteristic, and the multiple second outcoupling grating units adopt The second diopter diffracts light of the second optical characteristic. Alternatively, it can be understood that the plurality of first outcoupling grating units has a first diopter when diffracting light of the first optical characteristic, and the plurality of second outcoupling grating units has a second diopter when diffracting light of the second optical characteristic. Wherein, the above-mentioned first diopter is different from the second diopter.

In this possible implementation manner, since the multiple first outcoupling grating units and the second outcoupling grating units have different diopters to light, virtual images with different depths can be generated.

Optionally, in a possible implementation manner of the first aspect, the imaging depth of the image of the light beam diffracted by the plurality of first outcoupling grating units is the first depth, and the imaging depth of the light beam diffracted by the plurality of second outcoupling grating units is The image depth of the beam imaging is the second depth. Or it can be understood that the image depth of the image formed by the light beams diffracted by a plurality of first outcoupling grating units at the human eye is the first depth, and the image depth of the image formed by the light beams diffracted by a plurality of second outcoupling grating units at the human eye is the first depth. Two depths. Wherein, the first depth is different from the second depth. The first depth and the second depth are based on the same position. For example, when the display device module is applied to a head-mounted AR device, it may be based on the human eye position when the user wears the AR device correctly.

In this possible implementation mode, compared with the consistent diopter provided by the monolithic continuous grating in the prior art, which can only realize single-depth image display, the display device module provided by the embodiment of the present application can realize multi-depth image display .

Optionally, in a possible implementation manner of the first aspect, the above-mentioned first optical characteristic is the wavelength of red light, the second optical characteristic is the wavelength of green light, and the display device module further includes a plurality of third coupling a plurality of third outcoupling grating units are fixed on the optical waveguide; a plurality of third outcoupling grating units are used to diffract the light of the third optical characteristic in the light beam and couple the diffracted light out, the third The optical property is the wavelength of blue light. Or it can be understood that the three outcoupling grating units (ie, the first outcoupling grating unit, the second outcoupling grating unit and the third outcoupling grating unit) respectively correspond to the three-color images of the virtual image.

In this possible implementation manner, the display device module realizes the display of color images through three ways of coupling out the grating unit. Compared with the structure in the prior art that requires the use of multi-layer optical waveguides or multi-layer gratings, the thickness and weight of the display device module can be reduced, thereby improving user experience.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned display device module further includes multiple first coupling grating units and multiple second coupling grating units, and the multiple first coupling grating units The unit and multiple second coupling grating units are fixed on the optical waveguide, and multiple first coupling grating units and multiple second coupling grating units are distributed alternately; multiple first coupling grating units are used to receive the The light beam of the fourth optical characteristic diffracts the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and transmits the light of the first optical characteristic to the optical waveguide; a plurality of second coupling grating units are used to receive the light emitted by the image engine The light beam diffracts the light of the fifth optical characteristic in the light beam into the light of the second optical characteristic, and transmits the light of the second optical characteristic to the optical waveguide. The fourth optical characteristic is different from the fifth optical characteristic, that is, the third polarization state of the light corresponding to the fourth optical characteristic is different from the fourth polarization state of the light corresponding to the fifth optical characteristic, or, the fourth polarization state of the light corresponding to the fourth optical characteristic The fourth incident angle of the light corresponding to the three incident angles and the fifth optical characteristic is different. The optical waveguide is specifically used to totally reflect the light of the first optical feature and propagate to a plurality of first outcoupling grating units; the optical waveguide is specifically used to totally reflect the light of the second optical feature and propagate to a plurality of second coupling grating units. out of the raster unit. The plurality of first incoupling grating units is different from the plurality of second incoupling grating units. It can be understood that a differentially diffractive refraction grating can also be introduced.

In this possible implementation manner, the display device module further introduces an in-coupling grating unit that differentially diffracts light of different polarization states or different incident angles. Multiple first in-coupling grating units correspond to multiple first out-coupling grating units, and multiple second in-coupling grating units correspond to multiple second out-coupling grating units to jointly realize differential or selective diffraction and further improve The effect of differential diffraction.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned display device module further includes multiple first coupling grating units and multiple second coupling grating units, and the multiple first coupling grating units The unit and multiple second coupling grating units are fixed on the optical waveguide, and multiple first coupling grating units and multiple second coupling grating units are distributed alternately; multiple first coupling grating units are used to receive the light beam, and diffract the light of the first optical characteristic in the light beam, and transmit the diffracted light of the first optical characteristic to the optical waveguide; multiple second coupling grating units are used to receive the light beam emitted by the image engine, And it is used to diffract the light of the second optical characteristic in the light beam, and transmit the diffracted light of the second optical characteristic to the optical waveguide; the first wavelength of the light corresponding to the first optical characteristic and the wavelength of the light corresponding to the second optical characteristic The second wavelength is different.

In this possible implementation manner, the display device module further introduces an in-coupling grating unit that differentially diffracts light of different wavelengths. Multiple first in-coupling grating units correspond to multiple first out-coupling grating units, and multiple second in-coupling grating units correspond to multiple second out-coupling grating units to jointly realize differential or selective diffraction and further improve The effect of differential diffraction.

Optionally, in a possible implementation manner of the first aspect, the aforementioned multiple first coupling-in grating units have the same area and are uniformly distributed, and the multiple second coupling-in grating units have the same area and are uniformly distributed. Even distribution can be understood as meaning that the distance between two adjacent coupling-in grating units is the same in a certain direction on the plane where the multiple first coupling-in grating units and the multiple second coupling-in grating units are located. Even distribution can also be understood as a close arrangement of multiple first coupling grating units and multiple second coupling grating units. Wherein, the distance between two adjacent coupling-in grating units can be understood as the distance between the center points of two adjacent coupling-in grating units. Of course, this distance is only described by the center point of the grating unit, and it can also be The distance is calculated by means of the same side of the grating unit or the same reference point, etc., which is not limited here.

In this possible implementation, since the in-coupling grating only diffracts the light beam once, the in-coupling grating can be controlled to diffract the light through uniform distribution, and two parts of light with uniform light energy can be obtained.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned multiple first outcoupling grating units include at least two first outcoupling grating units distributed in the first direction, at least two first Among the outcoupling grating units, the farther the first outcoupling grating unit is from the image engine, the higher the coverage per unit area. The first direction is the direction from close to the image engine to away from the image engine. Wherein, the coverage per unit area can be understood as: the duty ratio of the grating unit in the unit area, or the ratio of the area of the grating unit in the unit area to the total area of the unit area. The higher the unit area coverage of the first outcoupling grating unit farther away from the image engine in the first direction can be understood as: in the first direction, select two areas with the same area, wherein the farther away from the image engine The larger the coverage (duty cycle) of the first outcoupling grating unit in the area of . In order to achieve higher coverage per unit area of the first outcoupling grating unit that is farther away from the image engine in the first direction, possible implementations include: in the first direction, each grating unit has the same area, and the grating unit within a unit area The density of cells increases. Alternatively, the density of the grating units in a unit area remains unchanged, and the area of each grating unit increases. It can be understood that the above two ways are just examples. In practical applications, there may be other ways to make the coverage per unit area of the first outcoupling grating unit farther away from the image engine higher, which is not limited here.

In this possible implementation, by adjusting the number and area of the first outcoupling grating units in the first outcoupling grating units in the first direction, it is possible to control the light energy coupled out of the optical waveguide in the entire exit pupil. The area is evenly distributed.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned outcoupling region of the optical waveguide is divided into N subregions, and the total number of outcoupling grating units included in each subregion along the first direction The proportion of the area in the area of each sub-region gradually increases, N is a positive integer greater than 1, the outcoupling region includes a plurality of first outcoupling grating units and a plurality of second outcoupling grating units, and the outcoupling grating unit includes multiple A part of the first outcoupling grating unit in the first outcoupling grating unit and a part of the second outcoupling grating unit in the plurality of second outcoupling grating units; the first outcoupling grating in each sub-region is specifically used for light One-Nth of the light energy of the light beam propagating in the waveguide is diffracted and coupled out to the human eye for imaging.

In this possible implementation, by adjusting the duty cycle of the first outcoupling grating unit in the spatial distribution density control area of each first outcoupling grating unit, the light energy of the exiting optical waveguide can be uniform in the entire exit pupil area. distributed.

Optionally, in a possible implementation manner of the first aspect, the projections of the above-mentioned multiple first outcoupling grating units in the second direction of the target plane partially overlap, and the second direction is The output grating unit diffracts and couples the light of the first optical characteristic to the direction perpendicular to the human eye, and the sharp angle between the target plane and the surface of the optical waveguide away from the human eye is smaller than the threshold value, or the target plane is far away or away from the human eye on the optical waveguide. Close to the surface of the human eye; the projections of the plurality of second outcoupling grating units on the second direction of the target plane partially overlap.

In this possible implementation manner, it is possible to prevent the light rays in the second direction from being diffracted by the previous grating unit, and no light rays are diffracted from the partially overlapping gratings, thereby reducing the loss of virtual images.

Optionally, in a possible implementation manner of the first aspect, the projections of the above-mentioned multiple first outcoupling grating units in the second direction of the target plane do not overlap, and the second direction is The output grating unit diffracts and couples the light of the first optical characteristic to the direction perpendicular to the human eye, and the sharp angle between the target plane and the surface of the optical waveguide away from the human eye is smaller than the threshold value, or the target plane is far away or away from the human eye on the optical waveguide. Close to the surface of the human eye; the projections of the plurality of second outcoupling grating units on the second direction of the target plane do not overlap.

In this possible implementation, it is possible to prevent the light in the second direction from being diffracted by the previous grating unit, that is, all the light in the light beam is coupled out of the grating unit to be diffracted and coupled out to the human eye for imaging, avoiding the virtual image due to Missing or darkened images due to occlusion.

Optionally, in a possible implementation manner of the first aspect, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are reflective diffraction gratings, and the plurality of first outcoupling grating units The multiple second outcoupling grating units are fixed on the surface of the optical waveguide opposite to the light output surface of the optical waveguide, or the multiple first outcoupling grating units and the multiple second outcoupling grating units are fixedly embedded in the optical waveguide.

Optionally, in a possible implementation manner of the first aspect, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are transmission diffraction gratings, and the plurality of first outcoupling grating units The plurality of second outcoupling grating units are fixed on the light out surface of the optical waveguide.

Among the above possible implementations, reflective or transmissive diffraction gratings can be selected according to the setting orientation requirements of specific application scenarios, so as to achieve high adaptation of display device modules and improve user experience.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned optical waveguide, multiple first outcoupling grating units, and multiple second outcoupling grating units are also used to transmit ambient light. Allows ambient light to propagate to the human eye.

In this possible implementation manner, the light engine system is used to generate light, and direct the generated light to the optical waveguide system, and the light generated by the light engine system is light carrying virtual image information. The optical waveguide system is used to transmit and couple the light from the light engine system into the human eye for imaging, so that the user can see the fused image including the virtual image and the real image through the augmented reality device.

Optionally, in a possible implementation manner of the first aspect, the above-mentioned optical waveguide includes a light incident surface facing the image engine and a light exit surface facing the human eye, the light incident surface is used for receiving light beams, and the light exit surface is used for The light beams diffracted by the multiple first outcoupling grating units and the multiple second outcoupling grating units are propagated to human eyes for imaging.

Optionally, in a possible implementation manner of the first aspect, the light exit surfaces of the plurality of first outcoupling grating units and the plurality of second outcoupling grating units face human eyes.

Optionally, in a possible implementation of the first aspect, the above-mentioned multiple first outcoupling grating units and multiple second outcoupling grating units are volume holographic grating VHG, surface relief grating SRG, metasurface diffraction At least one of gratings.

Optionally, in a possible implementation manner of the first aspect, the multiple first outcoupling grating units and the multiple second outcoupling grating units are sparsely arranged, that is, the multiple first outcoupling grating units and There are gaps at a preset distance between the plurality of second outcoupling grating units, so that the interference to the light in the real scene outside is minimal, so that the optical waveguide has better ambient light transmittance.

The second aspect of the embodiments of the present application provides a display device module, which can be applied to AR devices, vehicle-mounted head up display (HUD) devices, and the like. The display device module includes: an optical waveguide and a plurality of outcoupling grating units, the plurality of outcoupling grating units including at least two outcoupling grating units distributed in a first direction, at least two outcoupling grating units in the distance image engine The farther the outcoupling grating unit has the higher coverage per unit area, the first direction is the direction from adjacent to the image engine to away from the image engine; the optical waveguide is used to receive the light beam from the image engine, and propagate to multiple outcoupling grating units Light beam; multiple outcoupling grating units are fixed on the optical waveguide, and the multiple outcoupling grating units are used to diffract the beam propagating in the optical waveguide and couple out the diffracted light; wherein, the coverage per unit area can be understood as: unit The duty cycle of the grating elements in the area, or the ratio of the area of the grating elements in the unit area to the total area of the unit area. The higher the unit area coverage of the first outcoupling grating unit farther away from the image engine in the first direction can be understood as: in the first direction, select two areas with the same area, wherein the farther away from the image engine The larger the coverage (duty cycle) of the first outcoupling grating unit in the area of . In order to achieve higher coverage per unit area of the first outcoupling grating unit that is farther away from the image engine in the first direction, possible implementations include: in the first direction, each grating unit has the same area, and the grating unit within a unit area The density of cells increases. Alternatively, the density of the grating units in a unit area remains unchanged, and the area of each grating unit increases. It can be understood that the above two ways are just examples. In practical applications, there may be other ways to make the coverage per unit area of the first outcoupling grating unit farther away from the image engine higher, which is not limited here.

In this embodiment, by adjusting the number and area of the first outcoupling gratings in the first outcoupling grating units in the first direction, the light energy outcoupled from the optical waveguide can be controlled to distribute evenly in the entire exit pupil region . Or by controlling the ratio of the light energy diffracted each time to the total incident light energy when the light beam is diffracted multiple times in the first direction, the light energy is evenly coupled out from the outcoupling grating, thereby ensuring that the light energy is in the exit pupil area and the viewing angle. Uniformity of distribution within the field angle.

Optionally, in a possible implementation manner of the second aspect, the above-mentioned outcoupling region of the optical waveguide is divided into N subregions, and the total number of outcoupling grating units included in each subregion along the first direction The proportion of the area in the area of each sub-region gradually increases, N is a positive integer greater than 1, the outcoupling region includes a plurality of first outcoupling grating units and a plurality of second outcoupling grating units, and the outcoupling grating unit includes multiple A part of the first outcoupling grating units in the first outcoupling grating units and a part of the second outcoupling grating units in the plurality of second outcoupling grating units.

In this possible implementation, by adjusting the duty cycle of the first outcoupling grating unit in the spatial distribution density control area of each first outcoupling grating unit, the light energy of the exiting optical waveguide can be uniform in the entire exit pupil area. distributed.

Optionally, in a possible implementation manner of the second aspect, each of the above-mentioned subregions is specifically used to diffract one-Nth of the light energy of the light beam propagating in the optical waveguide and couple it out to the human eye for imaging.

In this possible implementation, each of the N subregions is specifically used to diffract one-Nth of the light energy of the light beam propagating in the optical waveguide and couple it out to the human eye for imaging, so that the output of the optical waveguide can be realized. The light energy is evenly distributed throughout the exit pupil area.

Optionally, in a possible implementation of the second aspect, the areas of the outcoupling grating units in each of the aforementioned subregions are equal, and the number of multiple outcoupling grating units included in each subregion in the first direction is gradually increase.

In this possible implementation manner, the uniform distribution of light energy is controlled by controlling the number of outcoupling grating units in the sub-region, that is, by controlling the arrangement density of the outcoupling grating units.

Optionally, in a possible implementation manner of the second aspect, the above-mentioned multiple outcoupling grating units are distributed in an array and/or sparsely, that is, multiple first outcoupling grating units and multiple second outcoupling grating units There is a preset distance gap between the output grating units, so that the interference to the real scene light outside is minimal, so that the optical waveguide has a better ambient light transmittance.

Optionally, in a possible implementation manner of the second aspect, the above-mentioned multiple outcoupling grating units are specifically configured to totally diffract all the light in the light beam propagating in the optical waveguide.

The third aspect of the embodiments of the present application provides a display device module, which can be applied to AR devices, vehicle-mounted head up display (HUD) devices, and the like. The display device module includes: an optical waveguide and multiple outcoupling grating units, the optical waveguide is used to receive light beams from the image engine, and transmit light beams to the multiple outcoupling grating units; the multiple outcoupling grating units are fixed on the optical waveguide, Multiple outcoupling grating units are used to diffract the beam propagating in the optical waveguide and couple out the diffracted light; multiple outcoupling grating units are arranged in an array in the first direction and the second direction on the target plane, The first direction and the second direction are not perpendicular, the acute angle between the target plane and the light-emitting surface on the optical waveguide is smaller than a threshold, or the target plane is the light-emitting surface or the surface opposite to the light-emitting surface on the optical waveguide.

In this embodiment, since the projections of all the grating units in the horizontal direction are closely arranged, the light beam will eventually be incident on a certain grating unit before reaching the lower edge of the optical waveguide and be diffracted out of the optical waveguide, so the utilization rate of light energy is high. Furthermore, the display device module can realize high utilization rate of light energy and uniform distribution of outcoupled light energy in the exit pupil area and the viewing angle. In addition, each grating unit is embedded in the optical waveguide and placed obliquely. The grating units are sparsely arranged in the direction of the user's visual axis, which has minimal interference with the light of the real scene outside, and the optical waveguide has better ambient light transmittance.

Optionally, in a possible implementation manner of the third aspect, the above-mentioned multiple outcoupling grating units are distributed among multiple outcoupling gratings, and each outcoupling grating includes a part of the outcoupling grating units among the multiple outcoupling grating units. Grating unit; one side of the plurality of outcoupling gratings is in contact with the surface of the optical waveguide opposite to the light output surface, and the other side of the plurality of outcoupling gratings is in contact with the light output surface.

In this possible implementation manner, it is ensured that all the light in the light beam emitted by the image engine is diffracted, so as to improve the utilization rate of the light beam.

Optionally, in a possible implementation manner of the third aspect, the above-mentioned multiple outcoupling grating units are specifically configured to fully diffract all the light in the light beam propagating in the optical waveguide and outcouple it to the human eye for imaging.

In this possible implementation manner, all the light in the light beam is fully diffracted to improve the utilization rate of light energy.

Optionally, in a possible implementation manner of the third aspect, the projections of the above-mentioned multiple outcoupling gratings in the second direction of the target plane partially overlap, and the second direction is to combine the light beam with the multiple outcoupling grating units. The direction of diffraction and outcoupling to the human eye is vertical, the sharp angle between the target plane and the surface of the optical waveguide away from the human eye is smaller than the threshold, or the target plane is the surface of the optical waveguide that is far away from or close to the human eye.

In this possible implementation manner, it is possible to prevent the light rays in the second direction from being diffracted by the previous grating unit, and no light rays are diffracted from the partially overlapping gratings, thereby reducing the loss of virtual images.

Optionally, in a possible implementation manner of the third aspect, the projections of the above-mentioned multiple outcoupling grating units in the second direction of the target plane do not overlap, and the second direction is the same as that of the multiple outcoupling grating units. The direction in which the light beam is diffracted and coupled to the human eye is perpendicular, the sharp angle between the target plane and the surface of the optical waveguide away from the human eye is smaller than the threshold, or the target plane is the surface of the optical waveguide that is far away from or close to the human eye.

In this possible implementation, it is possible to prevent the light in the second direction from being diffracted by the previous grating unit, that is, all the light in the light beam is coupled out of the grating unit to be diffracted and coupled out to the human eye for imaging, avoiding the virtual image due to Missing or darkened images due to occlusion.

Optionally, in a possible implementation manner of the third aspect, the multiple outcoupling grating units are distributed among the multiple outcoupling gratings, and each outcoupling grating includes part of the outcoupling grating units in the multiple outcoupling grating units One side of the multiple outcoupling gratings is in contact with the surface of the optical waveguide away from the human eye, and the other side of the multiple outcoupling gratings is in contact with the surface of the optical waveguide close to the human eye.

Optionally, in a possible implementation manner of the third aspect, the above-mentioned multiple outcoupling grating units are distributed in an array and/or sparsely, that is, multiple first outcoupling grating units and multiple second outcoupling grating units There is a preset distance gap between the output grating units, so that the interference to the real scene light outside is minimal, so that the optical waveguide has a better ambient light transmittance.

Optionally, any possible implementation manner of the third aspect is similar to any possible implementation manner of the first aspect, and reference may be made to the description of any possible implementation manner of the first aspect, and details are not repeated here.

The fourth aspect of the embodiment of the present application provides a display device, the display device includes: an image engine and a display module; the image engine is used to emit light beams; the display module includes any possible The display device module in the implementation manner, the second aspect or any possible implementation manner of the second aspect, the third aspect or any possible implementation manner of the third aspect.

Optionally, in a possible implementation manner of the fourth aspect, the above-mentioned display device is a vehicle-mounted HUD device.

The fifth aspect of the embodiment of the present application provides a display device, which is an augmented reality AR device or a mixed reality MR device, and is characterized in that it includes: a left-eye display module, a right-eye display module, a middle case, and Legs; the middle shell is used to fix the left-eye display module, the right-eye display module and the mirror legs, and the left-eye display module and/or the right-eye display module include the first aspect or any possible implementation of the first aspect manner, the second aspect or any possible implementation manner of the second aspect, the third aspect or any possible implementation manner of the third aspect.

The sixth aspect of the embodiment of the present application provides an image display method, which can be applied to a display device module, and the display device module includes: an optical waveguide, a plurality of first outcoupling grating units, and a plurality of second outcoupling grating units A grating unit, a plurality of first outcoupling grating units fixed to the optical waveguide, a plurality of second outcoupling grating units fixed in the optical waveguide, and a plurality of first outcoupling grating units and a plurality of second outcoupling grating units alternately distributed; The optical waveguide receives the light beam from the image engine, and propagates the light beam to a plurality of first outcoupling grating units and a plurality of second outcoupling grating units; the plurality of first outcoupling grating units diffract light of the first optical characteristic in the light beam and coupling out the diffracted light; multiple second outcoupling grating units diffract the light of the second optical characteristic in the light beam and couple out the diffracted light, the first optical characteristic and the second optical characteristic are different.

Optionally, in a possible implementation manner of the sixth aspect, the above step: the plurality of first outcoupling grating units diffract the light of the first optical characteristic in the light beam and couple out the diffracted light, including: A plurality of first outcoupling grating units diffracts the light of the first optical characteristic and couples out the light after total diffraction; a plurality of second outcoupling grating units diffracts the light of the second optical characteristic in the light beam and diffracts the light of the second optical characteristic The subsequent light outcoupling includes: a plurality of second outcoupling grating units perform total diffraction on the light with the second optical characteristic and couple out the total diffracted light.

Optionally, in a possible implementation manner of the sixth aspect, the above-mentioned first optical characteristic and the second optical characteristic are different, including: the first wavelength of light corresponding to the first optical characteristic and the first wavelength of light corresponding to the second optical characteristic The second wavelength of the light is different; or, the first polarization state of the light corresponding to the first optical characteristic is different from the second polarization state of the light corresponding to the second optical characteristic; or, the first incident angle of the light corresponding to the first optical characteristic The second incident angle of the light corresponding to the second optical characteristic is different.

Optionally, in a possible implementation manner of the sixth aspect, the above-mentioned display device module further includes multiple first coupling grating units and multiple second coupling grating units, and the multiple first coupling grating units The unit and multiple second coupling grating units are fixed on the optical waveguide, and multiple first coupling grating units and multiple second coupling grating units are distributed alternately; multiple first coupling grating units receive the light beam emitted by the image engine, diffract the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and transmit the light of the first optical characteristic to the optical waveguide; multiple second coupling-in grating units receive the light beam emitted by the image engine, and transmit the light of the first optical characteristic in the light beam The light of the five optical characteristics is diffracted into the light of the second optical characteristic, and the light of the second optical characteristic is transmitted to the optical waveguide; the third polarization state of the light corresponding to the fourth optical characteristic and the fourth polarization state of the light corresponding to the fifth optical characteristic The polarization states are different, or the third incident angle of the light corresponding to the fourth optical characteristic is different from the fourth incident angle of the light corresponding to the fifth optical characteristic.

Optionally, in a possible implementation manner of the sixth aspect, the above-mentioned multiple first outcoupling grating units use the first diopter to diffract the light of the first optical characteristic, and the multiple second outcoupling grating units use The second diopter diffracts light of a second optical characteristic, the first diopter being different from the second diopter.

Optionally, in a possible implementation manner of the sixth aspect, the imaging depth of the image of the light beam diffracted by the plurality of first outcoupling grating units is the first depth, and the image depth of the imaging beam diffracted by the plurality of second outcoupling grating units is The image depth of the beam imaging is the second depth, and the first depth is different from the second depth.

Optionally, in a possible implementation manner of the sixth aspect, the first optical characteristic is the wavelength of red light, the second optical characteristic is the wavelength of green light, and the display device module further includes a plurality of third outcoupling A grating unit, a plurality of third outcoupling grating units are fixed on the optical waveguide; a plurality of third outcoupling grating units diffract the light of the third optical characteristic in the light beam and couple out the diffracted light, the third optical characteristic is blue light wavelength.

Optionally, any possible implementation manner of the sixth aspect is similar to any possible implementation manner of the first aspect, and reference may be made to the description of any possible implementation manner of the foregoing first aspect, and details are not repeated here.

The seventh aspect of the embodiment of the present application provides an image display method, the method can be applied to a display device module, the display device module includes: an optical waveguide and a plurality of outcoupling grating units, the optical waveguide receives the light beam from the image engine , and propagate light beams to multiple outcoupling grating units; multiple outcoupling grating units are fixed on the optical waveguide, and multiple outcoupling grating units. diffracting the light beam propagating in the optical waveguide and coupling out the diffracted light; the multiple outcoupling grating units include at least two outcoupling grating units distributed in the first direction, and the distance image in the at least two outcoupling grating units The farther the engine is, the higher the coverage per unit area of the outcoupling grating unit is. The first direction is the direction from adjacent to the image engine to away from the image engine.

Optionally, any possible implementation manner of the seventh aspect is similar to any possible implementation manner of the second aspect, and reference may be made to the description of any possible implementation manner of the second aspect above, and details are not repeated here.

The eighth aspect of the embodiment of the present application provides an image display method, the method can be applied to a display device module, the display device module includes: an optical waveguide and a plurality of outcoupling grating units, the optical waveguide is used to receive images from the image engine The light beam is transmitted to multiple outcoupling grating units; multiple outcoupling grating units are fixed on the optical waveguide, and the multiple outcoupling grating units are used to diffract the beam propagating in the optical waveguide and couple the diffracted light out ; A plurality of outcoupling grating units are arranged in an array on the first direction and the second direction on the target plane, the first direction and the second direction are not perpendicular, and the sharp angle between the target plane and the light-emitting surface on the optical waveguide is less than the threshold, or the target plane is the light-emitting surface or the surface of the optical waveguide opposite to the light-emitting surface.

Optionally, any possible implementation manner of the eighth aspect is similar to any possible implementation manner of the third aspect, and reference may be made to the description of any possible implementation manner of the third aspect above, and details are not repeated here.

It can be seen from the above technical solutions that the embodiment of the present application has the following advantages: the display module includes: an optical waveguide, a plurality of first outcoupling grating units and a plurality of second outcoupling grating units, and a plurality of first outcoupling grating units The unit and the plurality of second outcoupling grating units are fixed to the optical waveguide in the form of a staggered distribution; the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are respectively used to control the light of the first optical characteristic in the beam The light with the second optical characteristic is diffracted and coupled out to the human eye for imaging. On the one hand, the display device module completes differential diffraction control by setting out-coupling grating units with different functions, and then realizes, for example, the decomposition and combination of large viewing angles, the display of images with different depths, and the display of color images, etc. On the other hand, compared with the monolithic grating structure in the prior art, the multiple outcoupling grating units are more flexible, and the etching process is relatively simple, without multiple etching or multiple exposures.

Description of drawings

FIG. 1 is a schematic diagram of a head-mounted display device worn by a user;

FIG. 2 is a schematic diagram of a head-mounted display device;

Fig. 3 is a schematic diagram of a vehicle-mounted HUD device;

Fig. 4 is a schematic diagram of a diffractive optical waveguide structure provided by the embodiment of the present application;

Figures 5-7 are schematic diagrams of three types of diffractive optical waveguide architectures applied to the display device module provided by the embodiment of the present application;

Figures 8-11 are structural schematic diagrams of several display device modules provided by the embodiments of the present application;

Figures 12-14 are structural schematic diagrams of several outcoupling gratings provided by the embodiments of the present application;

15-17 are schematic structural diagrams of other display device modules provided by the embodiments of the present application.

Detailed ways

Embodiments of the present application are described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Those of ordinary skill in the art know that, with the development of technology and the emergence of new scenarios, the technical solutions provided in the embodiments of the present application are also applicable to similar technical problems.

The terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or modules is not necessarily limited to the expressly listed Instead, other steps or modules not explicitly listed or inherent to the process, method, product or apparatus may be included. The naming or numbering of the steps in this application does not mean that the steps in the method flow must be executed in the time or logical order indicated by the naming or numbering. The execution order of the technical purpose is changed, as long as the same or similar technical effect can be achieved. In addition, the "plurality" mentioned in the embodiments of the present application is only for distinguishing from "one", and "multiple" can be understood as referring to at least two.

In order to facilitate the understanding of the technical solution provided by the present application, some concepts are firstly introduced below.

1. Optical waveguide

An optical waveguide is a dielectric device that guides the propagation of light waves through it. The optical waveguide includes upper and lower surfaces. When the light in the optical waveguide is incident on the upper and lower surfaces of the waveguide, if the incident angle is greater than the critical angle, the light is totally reflected at the interface between the surface of the optical waveguide and air. The critical angle depends on the refractive index of the optical waveguide.

2. Diffraction of light

Diffraction of light refers to the phenomenon that light can bypass the edge of obstacles and deviate from the straight line during the propagation process.

3. Grating

A grating is an optical element composed of a large number of parallel slits (or reflective surfaces) of equal width and equal spacing. In a broad sense, any diffraction screen with spatial periodicity can be called a grating. Gratings can be divided into transmissive gratings and reflective gratings. Transmissive gratings are generally made by carving a large number of parallel notches on a glass sheet. The notches are opaque parts, and the smooth part between the two notches can transmit light, which is equivalent to a slit. The reflective grating is a grating that uses the reflected light diffraction between two notches. For example, if many parallel notches are carved on the surface coated with a metal layer, the smooth metal surface between the two notches can reflect light.

4. Field of view (FOV)

The field of view is the angle range of the image presented by the human eye. Outside this angle range, the user will not see the image. The exit pupil is a spatial area. When the intersection of the pupil of the eye and this area is not empty, all pixels on the image surface can be seen If the light is emitted from the point, the complete image can be seen; otherwise, the complete image cannot be seen.

5. Exit pupil

The image formed by the aperture stop of the optical system in the image space of the optical system is called the "exit pupil" (exit pupil) of the system, also known as the eye movement range, the exit pupil, often referred to as the Eyebox. The exit pupil size is used to measure the size of the "exit pupil" of the system. Ideally, the eye will have the same FOV anywhere in the eyebox.

6. Head up display (HUD)

HUD technology, also known as head-up display technology, has gradually been more and more widely used in the fields of automobiles, aerospace and navigation in recent years. For example, it can be applied to vehicles, and can also be applied to other vehicles such as airplanes, aerospace vehicles, and ships. For ease of understanding, the car HUD is taken as an example to describe. The AR-HUD that has emerged in recent years superimposes digital images on the real environment outside the car, allowing the driver to obtain the visual effect of augmented reality, which can be used for AR navigation, adaptive cruise, driveway, etc. Scenarios such as deviation warning.

The display device module in the embodiment of the present application can be applied to diffractive waveguide display devices, for example: near-eye display devices (including AR glasses, etc.), mixed reality (mixed reality, MR) devices, vehicle-mounted HUD devices, and the like.

FIG. 1 shows a schematic diagram of a head-mounted display device 100 worn by a user 102 . The head-mounted display device 100 may be used to display augmented reality images as well as physical objects in real-world background scenes. The head-mounted display device 100 may include a frame 104 (also referred to as a mirror frame or mirror frame in this embodiment) for positioning the device at a target viewing position relative to the eyes of a user 102 .

FIG. 2 shows a schematic diagram of the head-mounted display device 100 of FIG. 1 . As shown in FIG. 2 , the head-mounted display device 100 includes a right-eye display system 200a and a left-eye display system 200b. Right eye display system 200a or left eye display system 200b) may be used to both display virtual images to the user and allow the user to view the real environment. Wherein, the right-eye display system 200a may include a right-eye display module, the left-eye display system 200b may include a left-eye display module, and the head-mounted display device 100 includes a middle case and temples (or earpieces). 206, the middle case is used to fix the left-eye display module, the right-eye display module, and the mirror legs 206. The head-mounted display device 100 also includes a front case, the front case is connected to the middle case, and the front case is located in the head-mounted display device The outer surface is used to protect the left-eye display module and the right-eye display module. It should be understood that the front case may be a transparent visor.

Furthermore, Figure 2 schematically shows a microphone 202 that may be used to output acoustic information to a user. Such acoustic information may take any suitable form, including, but not limited to, computer-generated speech output in an appropriate language (as selected by the user), tones or other sounds not specific to any language, and/or any other suitable sounds. In some embodiments, other types of output may be provided by the head mounted display device 100, such as haptic/touch output.

Left-eye display system 200b and right-eye display system 200a may be positioned at viewing positions relative to the eyes via one or more securing mechanisms of frame 104 . For example, as shown in FIG. 2 , frame 104 may be supported by the user's ear via ear piece 206 and by the user's nose via nose bridge 208 to reduce sliding of frame 104 . It will be appreciated that the supports shown in FIG. 2 (such as earpieces 206, nosepieces, and bridge 208) are exemplary in nature and that the see-through display systems (right-eye display system 200a and left-eye display system 200a) of a head-mounted see-through display device The display system 200b) may be positioned at the viewing position via any suitable mechanism. For example, additional supports may be utilized, and/or one or more of the supports shown in FIG. 2 may be removed, replaced, and/or augmented to position the see-through display system at the viewing position. Furthermore, the see-through display system may be positioned at the viewing position by mechanisms other than supports that physically contact the user, as this application does not limit.

It should be understood that the left-eye display module and the right-eye display module in this embodiment may be referred to as display device modules.

Fig. 3 shows a possible application scenario provided for this application. This application scenario is an example where the HUD system is applied to a vehicle. The HUD system is used to project instrumentation information (vehicle speed, temperature, fuel level, etc.) and navigation information on the vehicle into the driver's field of vision through the windshield of the vehicle, where the virtual image corresponding to the navigation information can be superimposed on the real image outside the vehicle. Environmentally, the driver can obtain augmented reality visual effects, such as AR navigation, adaptive cruise, lane departure warning, etc. Since the virtual image corresponding to the navigation information needs to be combined with the real scene, the vehicle is required to have precise positioning and detection functions. Usually, the HUD system needs to cooperate with the advanced driving assistant system (ADAS) system of the car. For example, the virtual image about the speed of 20 kilometers per hour shown in FIG. 3 is imaged on the front windshield of the vehicle. Of course, imaging can also be performed at the position of the main driver's window of the vehicle, or virtual imaging can be performed on the passenger side window or in other areas (such as the instrument panel), which are not specifically limited here.

It should be understood that the above scenarios are just examples, and the display device module provided in this application may also be applied in other scenarios. The display device module provided in this application can also be applied to MR devices, etc., which is not specifically limited here.

In addition, FIG. 4 shows a diffractive optical waveguide architecture, which includes a micro-projector, an in-coupling area, a waveguide (also called an optical waveguide), and an out-coupling area. Wherein, a diffraction device-in-coupling grating is arranged in the in-coupling area, and a diffraction device-out-coupling grating is arranged in the out-coupling area. The general process of the diffractive optical waveguide is: the micro-projection optical machine projects the collimated image to the coupling grating of the diffractive optical waveguide (or the micro-projection optical machine propagates the image light to the coupling grating, and the coupling grating completes the image light collimation). The coupling-in grating uses the diffraction effect to deflect the projected image light as a whole, and couples it into the optical waveguide. And the deflected image light satisfies the total reflection condition in the optical waveguide, and propagates to the outcoupling grating in the way of total reflection, the outcoupling grating can expand the pupil, and redirect the light out of the optical waveguide into the human eye. It can be understood that a turning grating can also be arranged between the coupling-in grating and the outgoing grating, and the turning grating can redirect the light propagation direction and expand the pupil in the first dimension. Specifically, the outcoupling grating can perform pupil expansion in the second dimension. Wherein, the first dimension can be understood as one direction in the two-dimensional space (for example, the up-down direction), and the second dimension can be understood as another direction in the two-dimensional space (for example, the left-right direction).

Diffractive devices used in traditional diffractive optical waveguide technology, such as in-coupling gratings, inflection gratings, and out-coupling gratings, are usually monolithic structures with continuous distribution of surface microstructures, making it difficult to fine-grained selective diffraction control of incident light, modulation Low degrees of freedom. In order to achieve differential diffraction control, the entire diffraction surface needs to be designed and processed differently on the diffraction structure, resulting in increased design complexity and processing difficulty, and some surface defects will affect the diffraction effect of the entire diffraction device, affecting good products rate, leading to high cost of the device (for example, in order to achieve different diffraction functions, it needs to be prepared by repeated etching or multiple exposure techniques. This method is at the expense of the diffraction efficiency of the diffraction element. As the number of multiplexing increases, the diffraction the greater the drop in efficiency).

In order to solve the above problems, an embodiment of the present application provides a display device module, the outcoupling grating included in the module includes a first outcoupling grating array and a second outcoupling grating array, the first outcoupling grating array and the second outcoupling grating array The two outcoupling grating arrays are distributed alternately and have differential diffraction control. On the one hand, since the first outcoupling grating array does not need to realize the differential diffraction control separately, the processing cost brought by the implementation of the differential diffraction control in order to realize the whole chip structure in the prior art is reduced. On the other hand, differential diffraction control can be realized through the outcoupling grating structure of multiple outcoupling gratings.

The following describes several classic architectures in which the display device module provided by the embodiment of the present application is applied to the diffractive optical waveguide architecture, or several architectures that are understood to be applicable to gratings.

The first type: the diffractive optical waveguide structure includes an optical waveguide, an in-coupling grating and an out-coupling grating.

Referring to FIG. 5 , the in-coupling grating 502 and the out-coupling grating 503 are fixed on the optical waveguide 501 . The image light (generally the image light projected by the micro-projector) propagates to the optical waveguide 501 through the in-coupling grating 502, and then is coupled out of the waveguide by the out-coupling grating 503 and enters the human eye. When the image light passes through the outcoupling grating 503, the outcoupling grating 503 can expand the pupil along the propagation direction of the image light.

For specific functions of each component, reference may be made to the description in the aforementioned FIG. 4 , which will not be repeated here.

The second type: the diffractive optical waveguide structure includes an optical waveguide, an in-coupling grating, a turning grating and an out-coupling grating.

Referring to FIG. 6 , the incoupling grating 602 , the inflection grating 603 and the outcoupling grating 604 are fixed on the optical waveguide 601 . The image light (generally the image light projected by the micro-projector) propagates to the optical waveguide 601 through the coupling grating 602, and is guided to the turning grating 603 by the coupling grating 602. The turning grating 603 can expand the pupil of the incident image light in the first dimension , and then guided to the outcoupling grating 604, and then coupled out of the waveguide by the outcoupling grating 604 into the human eye. When the image light passes through the outcoupling grating 604, the outcoupling grating 604 can perform a pupil expansion operation in the second dimension along the propagation direction of the light.

For descriptions about the first dimension, the second dimension, etc., reference may be made to the foregoing description in FIG. 4 , which will not be repeated here.

The third type: the diffractive optical waveguide structure includes an optical waveguide, an in-coupling grating, multiple turning gratings and an out-coupling grating.

Please refer to FIG. 7 , the incoupling grating 702 , the inflection grating 703 a , the inflection grating 703 b , and the outcoupling grating 704 are fixed on the optical waveguide 701 . The image light (generally the image light projected by the micro-projector) propagates to the optical waveguide 701 through the coupling grating 702, and is guided by the coupling grating 702 to the deflection grating 703a and the deflection grating 703b respectively according to the incident angle range, that is, the coupling grating 702 will The FOV projected by the micro-projection engine is disassembled into two sub-FOVs. The inflection gratings 703a and 703b can expand the pupils of the incident image light in the first dimension, and then lead them to the outcoupling grating 704, and then resplice them into an angular continuous FOV to enter the human eye when they are coupled out of the waveguide by the outcoupling grating 704. When the image light passes through the outcoupling grating 704, the outcoupling grating 704 can perform a pupil expansion operation in the second dimension along the propagation direction of the light.

For descriptions about the first dimension, the second dimension, etc., reference may be made to the foregoing description in FIG. 4 , which will not be repeated here.

It can be understood that the above three cases are just examples, and there will be a large number of variants in practical applications, for example, some diffraction gratings are replaced by other geometric optical devices, or in the architecture of Figure 7, more turning gratings are used to support More sub-FOV transfers, etc.

The structure of the display device module provided by the embodiment of the present application is described below.

Please refer to FIG. 8 to FIG. 11 , which are schematic diagrams of several structures of a display device module provided by the embodiment of the present application. Among them, FIG. 8 can be understood as several side views of the display device module, and FIG. 9 can be understood as a structural diagram of the outcoupling grating 804 in FIG. 8 . FIG. 10 can be understood as several side views of the display device module, and FIG. 11 can be understood as a structural diagram of the outcoupling grating 804 in FIG. 10 .

The display device module includes an optical waveguide 803 and an outcoupling grating 804 . The outcoupling grating 804 includes a plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b. Among them, a plurality of first outcoupling grating units 804a are fixed on the optical waveguide 803, a plurality of second outcoupling grating units 804b are fixed on the optical waveguide 803, and a plurality of first outcoupling grating units 804a and a plurality of second outcoupling gratings The cells 804b are staggered. The optical waveguide 803 is used to receive the light beam from the image engine 801, and transmit the light beam to a plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b; a plurality of first outcoupling grating units 804a are used for diffracting the light of the first optical characteristic in the beam and coupling out the diffracted light; a plurality of second outcoupling grating units 804b for diffracting the light of the second optical characteristic in the beam and coupling out the diffracted light , the first optical characteristic is different from the second optical characteristic, and the plurality of first outcoupling grating units 804a is different from the plurality of second outcoupling grating units 804b.

Optionally, the plurality of first outcoupling grating units 804a and the plurality of second outcoupling grating units 804b are specifically used to transmit the diffracted light to the human eye for imaging, the human eye (or called the human eye) in the embodiment of the present application Position, human eye direction) is the human eye position or direction when the user uses the display device module correctly. For example: for display device modules applied to AR eyes, the position or direction of the human eye refers to the position or direction of the human eye when the user wears it in the correct way.

Where the multiple first outcoupling grating units 804a are different from the multiple second outcoupling grating units 804b, it means that the light diffracted by the multiple first outcoupling grating units is different from the light diffracted by the multiple second outcoupling grating units . Or it can be understood that the diffraction functions of the plurality of first outcoupling grating units 804 a and the plurality of second outcoupling grating units 804 b are different, rather than different structures and shapes. It can also be understood that the plurality of first outcoupling grating units 804a diffract the light of the first optical characteristic, and do not diffract the light of the second optical characteristic; The light is diffracted, and the light of the first optical characteristic does not diffract. For example: multiple first outcoupling grating units 804a are used to diffract only the light of the first optical characteristic in the beam and couple it to the human eye for imaging; multiple second outcoupling grating units 804b are used to only The light of the second optical characteristic is diffracted and coupled out to human eyes for imaging, and the first optical characteristic is different from the second optical characteristic. It can be understood that the "only" here does not mean that the grating unit has only one function, but is used to describe that the first outcoupling grating unit diffracts the light of the first optical characteristic of 804a, and does not diffract the light of the second optical characteristic. Diffraction (eg transmission). Described in another way, the multiple first outcoupling grating units 804a are also used to transmit the light of the second optical characteristic in the light beam, and the angle of the light of the second optical characteristic does not change before and after transmission; the optical waveguide 803 is also It is used to totally reflect the light of the second optical characteristic and transmit it to a plurality of second outcoupling grating units 804b; the plurality of second outcoupling grating units 804b are also used to transmit the light of the first optical characteristic in the light beam; the light The waveguide 803 is also used for totally reflecting the light of the first optical feature and propagating to a plurality of first outcoupling grating units 804a. The "transmission" in this embodiment can be understood as the exit phenomenon of the incident light after passing through the object, which can be understood as non-diffraction. It can be understood that the plurality of first outcoupling grating units 804a diffract the light of the first optical characteristic, and transmit the light of the second optical characteristic (also can be understood as non-diffraction); the plurality of second outcoupling grating units 804b diffracts the light of the second optical characteristic and transmits the light of the first optical characteristic. It can also be understood that the incident angle and outgoing angle of the light of the first characteristic on the multiple second outcoupling grating units 804b are the same, and the incident angle and outgoing angle of the light of the second characteristic on the multiple first outcoupling grating units 804a are the same. same.

In addition, a plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b are alternately distributed. Two out-coupling grating units. It can also be understood that there is a second outcoupling grating unit between two first outcoupling grating units, and there is a first outcoupling grating unit between two second outcoupling grating units. Of course, it is also possible that every two first outcoupling grating units are adjacent to two second outcoupling grating units. In some cases, this staggered distribution can also be understood as an alternating distribution. Further, the multiple first outcoupling grating units and the multiple second outcoupling grating units are alternately distributed on the same plane. Or the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are not on the same plane. For the case of not being on the same plane, for the light beam emitted by the image engine 801, if a plurality of first outcoupling grating units 804a diffract part of the light in the light beam, then a plurality of second outcoupling grating units 804b will diffract part of the light in the light beam. Another part of the light is diffracted. The plurality of first outcoupling grating units 804 a and the plurality of second outcoupling grating units 804 b jointly realize diffracting all the light in the light beam emitted by the image engine 801 .

Optionally, the optical characteristics (the first optical characteristic and the second optical characteristic) may refer to parameters related to the incident light beam, such as the wavelength of the incident light, the polarization state of the incident light, the range of the incident angle of the incident light, and the like. The difference between the first optical characteristic and the second optical characteristic can be understood as that the first wavelength of light corresponding to the first optical characteristic is different from the second wavelength of light corresponding to the second optical characteristic; or, the light corresponding to the first optical characteristic The first polarization state is different from the second polarization state of the light corresponding to the second optical characteristic; or, the first incident angle of the light corresponding to the first optical characteristic is different from the second incident angle of the light corresponding to the second optical characteristic. Furthermore, the display device module can selectively and differentially modulate the light of each optical characteristic in the beam according to the incident angle, wavelength, polarization state, etc. of the beam.

Optionally, the outcoupling grating 804 includes at least two kinds of outcoupling grating arrays with different functions. Taking the two functions as an example, the outcoupling grating unit 804 includes a plurality of first outcoupling grating units (also referred to as first outcoupling grating units). grating array) 804a and a plurality of second outcoupling grating units (also referred to as a second outcoupling grating array) 804b. That is, the first outcoupling grating array includes a plurality of first outcoupling grating units 804a, and the second outcoupling grating array includes a plurality of second outcoupling grating units 804b. Wherein, the grating units of the same grating array (a plurality of first outcoupling grating units 804a or a plurality of second outcoupling grating units 804b) cooperate to complete a light modulation effect. For example: synergistically complete the angle deflection of the incident light, or cooperate to complete the refractive effect of the lens on the light.

Optionally, the size of the grating unit in the grating array can be n millimeters, and it can also be as large as n centimeters on some large-scale optical combiners. Each grating unit can be a volume holographic grating (volume holographic grating, VHG), Surface relief grating (surface rising grating, SRG), metasurface and other diffractive optical elements. The size and shape of each grating unit in the same grating array can be different, the gap between adjacent grating units can be different, and the number of grating units included in the grating array can be set according to actual needs, which is not limited here. The size, shape, gap and quantity mentioned above can be designed according to the requirement of spatially selective modulation of the incident light, which is not specifically limited here.

The outcoupling grating 804 in the embodiment of the present application may be a transmissive diffraction grating or a reflective diffraction grating, etc., which are not specifically limited here. If the outcoupling grating 804 is a reflective diffraction grating, the light incident surfaces and light output surfaces of the plurality of first outcoupling grating units 804 a and the plurality of second outcoupling grating units 804 b face human eyes. A plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b are fixed on the surface of the optical waveguide 803 opposite to the light exit surface of the optical waveguide 803, or a plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units The two outcoupling grating units 804b can be fixedly embedded in the optical waveguide 803 . If the outcoupling grating 804 is a transmission diffraction grating, the light emitting surfaces of the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units 804b face the human eye, and the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units The light incident surfaces of the two outcoupling grating units 804b face away from human eyes. The plurality of first outcoupling grating units 804 a and the plurality of second outcoupling grating units 804 b can be fixed on the light emitting surface of the optical waveguide 803 .

Optionally, the circular shape of the grating unit in the embodiment of the present application is just an example, and does not represent the shape of the actual grating unit. The shape of the actual grating unit can also be made into a square, regular polygon, etc., which is not limited here .

Optionally, the area of each outcoupling grating unit in the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units 804b may be the same or different.

Exemplarily, in the case that the area of each outcoupling grating unit in the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units 804b is the same, the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units The structure of the two outcoupling grating units 804b may be as shown in FIG. 9 . In the case that the areas of the multiple first outcoupling grating units 804a are different, the structures of the multiple first outcoupling grating units 804a and the multiple second outcoupling grating units 804b can be shown in the figure 11.

Optionally, the plurality of first outcoupling grating units 804a includes at least two first outcoupling grating units distributed in the first direction, and the farthest one from the image engine 801 among the at least two first outcoupling grating units 804a is The higher the unit area coverage of an outcoupling grating unit is, the first direction is the direction from close to the image engine 801 to away from the image engine 801 . Wherein, the coverage per unit area can be understood as: the duty ratio of the grating unit in the unit area, or the ratio of the area of the grating unit in the unit area to the total area of the unit area. The higher the unit area coverage of the first outcoupling grating unit farther away from the image engine in the first direction can be understood as: in the first direction, select two areas with the same area, wherein the farther away from the image engine The larger the coverage (duty cycle) of the first outcoupling grating unit in the area of . In order to achieve higher coverage per unit area of the first outcoupling grating unit that is farther away from the image engine in the first direction, possible implementations include: in the first direction, each grating unit has the same area, and the grating unit within a unit area The density of cells increases. Alternatively, the density of the grating units in a unit area remains unchanged, and the area of each grating unit increases. It can be understood that the above two ways are just examples. In practical applications, there may be other ways to make the coverage per unit area of the first outcoupling grating unit farther away from the image engine higher, which is not limited here.

The distribution of the plurality of second outcoupling grating units 804b is similar to the distribution of the plurality of first outcoupling grating units 804a, and will not be repeated here. By adjusting the number and area of the first outcoupling gratings in the plurality of first outcoupling grating units in the first direction, the light energy coupled out of the optical waveguide can be controlled to distribute evenly in the entire exit pupil area.

Optionally, the plurality of first outcoupling grating units 804a and the plurality of second outcoupling grating units 804b as a whole may be divided into N subregions (or it may be understood that the outcoupling region of the optical waveguide 803 is divided into N subregions ), the proportion of the total area of the outcoupling grating unit included in each subregion in the area of each subregion gradually increases along the first direction, N is a positive integer greater than 1, and the outcoupling grating unit includes a plurality of A part of the first outcoupling grating unit in the first outcoupling grating unit 804a and a part of the second outcoupling grating unit in the plurality of second outcoupling grating units 804b; each of the N subregions is specifically used for the optical waveguide One Nth of the light energy of the light beam propagating in 803 is diffracted and coupled out to the human eye for imaging. In this possible implementation, each of the N subregions is specifically used to diffract one-Nth of the light energy of the light beam propagating in the optical waveguide 803 and couple it to the human eye for imaging, so that the light output can be realized. The light energy of the waveguide 803 is evenly distributed throughout the exit pupil area. Specifically, the above-mentioned area ratio may be controlled by means of the number, density, or area of the outcoupling grating units, which is not specifically limited here.

Optionally, the density of the outcoupling grating in the first direction may also be controlled to control light energy utilization. That is, a small-area grating unit is arranged in the sub-area where the light beam is first incident, and the area of the grating unit is gradually increased in the later incident sub-area. By adjusting the area of each grating unit distributed in different sub-areas, the light energy in the exit pupil area is adjusted. The distribution realizes finer-grained regulation, and at the same time realizes high utilization rate of incident light energy, avoiding loss of light energy.

It can be understood that the number of outcoupling grating units (ie, the first outcoupling grating unit and the second outcoupling grating unit), the area of the outcoupling grating unit, and the gap between adjacent outcoupling grating units shown in FIG. It is just an example, and the details are not limited here.

There are many ways to fix the plurality of first outcoupling grating units 804a and the plurality of second outcoupling grating units 804b to the optical waveguide 803, specifically, the plurality of first outcoupling grating units 804a and the plurality of second outcoupling grating units The output grating unit 804b is fixed on the surface (inner surface or outer surface) of the optical waveguide 803 away from the human eye or close to the human eye. The above-mentioned multiple first outcoupling grating units 804a and multiple second outcoupling grating units 804b are fixed to the optical waveguide 803 in a manner that multiple first outcoupling grating units 804a and multiple second outcoupling grating units 804b It is fixedly embedded inside the optical waveguide 803 . If it is fixedly embedded in the optical waveguide 803, the outcoupling grating 804 can be parallel to the surface of the optical waveguide 803 away from the human eye, or the acute angle between the outcoupling grating 804 and the surface of the optical waveguide 803 away from the human eye can be smaller than a threshold . Exemplarily, the plurality of first outcoupling grating units 804a and the plurality of second outcoupling grating units 804b are fixed on the outer surface of the optical waveguide 803 facing away from the human eye, as shown in (A) in FIG. The outcoupling grating unit 804a and the multiple second outcoupling grating units 804b are fixed on the inner surface of the optical waveguide 803 away from the human eye as shown in (B) in FIG. The second outcoupling grating unit 804b is fixedly embedded in the optical waveguide 803 as shown in (C) of FIG. 8 . FIG. 9 is a schematic structural diagram of the grating unit 804 in FIG. 8 . A plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b are fixed on the outer surface of the optical waveguide 803 facing away from the human eye as shown in (A) in FIG. 804a and a plurality of second outcoupling grating units 804b are fixed on the inner surface of the optical waveguide 803 away from the human eye, as shown in (B) in FIG. The grating unit 804b is fixedly embedded in the optical waveguide 803 as shown in (C) of FIG. 10 . FIG. 11 is a schematic structural diagram of the outcoupling grating 804 in FIG. 10 .

Optionally, when the outcoupling grating 804 is fixedly embedded in the optical waveguide 803, the outcoupling grating 804 can be parallel to the surface of the optical waveguide 803 away from the human eye, or the side of the outcoupling grating 804 can be parallel to the optical waveguide 803 away from the human eye. The other side of the outcoupling grating 804 is in contact with the surface of the optical waveguide 803 adjacent to the human eye.

It can be understood that the structures of the display device modules shown in FIGS. 8 to 11 are just examples. For example, if the outcoupling grating 804 is a transmissive grating, the outcoupling grating 804 can also be arranged on the surface (inner surface or The outer surface). Another example: in the case that the outcoupling grating 804 is a relief grating, the surface of the outcoupling grating 804 may also be provided with a plurality of grooves and the like.

The outcoupling grating 804 in the embodiment of the present application can be understood as a grating with approximately 100% diffraction efficiency. Or it can be understood as the outcoupling grating 804 designed according to the target of 100% diffraction efficiency.

Optionally, the display device modules shown in FIGS. 8 to 11 may further include an image engine 801, and the optical waveguide 803 is specifically used to receive light beams from the image engine 801.

Optionally, the image engine 801 can be arranged on the side of the outer surface of the optical waveguide 803 away from the surface of the human eye, or on the side of the outer surface of the optical waveguide 803 that is close to the surface of the human eye, or on the side of the outer surface of the optical waveguide 803 that is far away from the surface of the human eye. One side of the collimated surface of the outer surface of the human eye surface, etc., the embodiment of the present application does not limit the position of the image engine 801, as long as the light beam emitted by the image engine 801 can enter the optical waveguide 803. In the embodiment of the present application, the image engine 801 may include any suitable components for generating images for display, including but not limited to a microdisplay and one or more light sources.

Optionally, in some embodiments, the graphics engine 801 may include a reflective microdisplay, such as a liquid crystal on silicon (LCoS) display. In other embodiments, the graphics engine 801 may include an emitting microdisplay, such as an organic light-emitting diode (OLED) array display type, an inorganic light-emitting diode (inorganic light-emitting diode, iLED) array display type, and/or or any other suitable microdisplay. Graphics engine 801 may include one or more light sources, such as an array of RGB LEDs, one or more white LEDs (e.g., with a color filter arrangement), laser beam scanning (LBS), and/or any suitable illumination source structure.

In the embodiment of the present application, the image engine 801 may display images based on electronic image content, and further, may serve as a light source to emit light based on electronic image content. The above-mentioned image engine can also be called an optical machine, a micro-projection optical machine, etc., and the image engine is used to generate light carrying virtual image information, and direct the generated light to the optical waveguide, and then couple out the grating unit (the first coupling The output grating unit and the second output grating unit) diffract the light and couple it to the human eye to form a virtual image corresponding to the virtual image information. The light of the virtual image and the light carrying the real environment information are imaged in human eyes, and then the user can see a fusion image including the virtual image and the real image. Furthermore, the light emitted by the image engine can be a collimated beam or not. If the light emitted by the image engine is not a collimated beam, the collimation function can also be realized by adding a coupling grating to the optical waveguide.

Optionally, the display device modules in FIGS. 8 to 11 may further include an in-coupling grating 802 , and the in-coupling grating 802 may be fixed on the surface of the optical waveguide 803 close to the image engine 801 . The in-coupling grating 802 is used for receiving the beam emitted by the image engine 801 and coupling the beam into the optical waveguide 803 . The coupling-in grating 802 includes a plurality of first coupling-in grating units and a plurality of second coupling-in grating units, and the plurality of first coupling-in grating units and the plurality of second coupling-in grating units are alternately distributed. Wherein, the structure of the coupling-in grating 802 is similar to that of the coupling-out grating 804 .

Optionally, a plurality of first coupling-in grating units are used to receive the light beam emitted by the image engine 801, diffract the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and transmit the light of the first optical characteristic to the optical waveguide 803; the optical waveguide 803 is specifically used to totally reflect the light of the first optical feature and propagate to a plurality of first outcoupling grating units 804a; a plurality of second incoupling grating units are used to receive the light emitted by the image engine 801 The light beam of the fifth optical characteristic diffracts the light of the fifth optical characteristic in the light beam into the light of the second optical characteristic, and transmits the light of the second optical characteristic to the optical waveguide 803; the optical waveguide 803 is specifically used to perform It is totally reflected and transmitted to a plurality of second outcoupling grating units 804b. The third polarization state of the light corresponding to the fourth optical characteristic is different from the fourth polarization state of the light corresponding to the fifth optical characteristic, or, the third incident angle of the light corresponding to the fourth optical characteristic is different from that of the light corresponding to the fifth optical characteristic The fourth angle of incidence is different.

Optionally, a plurality of first coupling grating units are used to receive the light beam emitted by the image engine 801, diffract the light of the first optical characteristic in the light beam, and transmit the diffracted light of the first optical characteristic to the light beam A waveguide 803; an optical waveguide 803, specifically used for total reflection of the light of the first optical feature and propagating to a plurality of first outcoupling grating units 804a; a plurality of second incoupling grating units for receiving the light beam emitted by the image engine 801 , and is used to diffract the light of the second optical characteristic in the light beam, and transmit the diffracted light of the second optical characteristic to the optical waveguide 803; the optical waveguide 803 is specifically used for total reflection of the light of the second optical characteristic and propagating to a plurality of second outcoupling grating units 804b. The first wavelength of light corresponding to the first optical characteristic is different from the second wavelength of light corresponding to the second optical characteristic.

Optionally, the plurality of first coupling-in grating units and the plurality of second coupling-in grating units are also used to collimate the light beam and transmit the collimated light to the optical waveguide 803 .

Further, the multiple first coupling-in grating units have the same area and are uniformly distributed, and the multiple second coupling-in grating units have the same area and are uniformly distributed. Furthermore, it can be realized that the in-coupling grating 802 can diffract light of two optical characteristics, and the energy of the light of the two optical characteristics is uniform.

Optionally, the projections of the plurality of first outcoupling grating units 804a in the second direction of the target plane partially overlap, and the second direction is to diffract and couple light of the first optical characteristic with the plurality of first outcoupling grating units 804a The direction going out to the human eye is vertical, the sharp angle between the target plane and the surface away from the human eye on the optical waveguide 803 is smaller than the threshold value, or the target plane is the surface away from or close to the human eye on the optical waveguide 803; multiple second couplers The projections of the output grating unit 804b in the second direction on the target plane partially overlap. In this possible implementation manner, it is possible to prevent the light rays in the second direction from being diffracted by the previous grating unit, and no light rays are diffracted from the partially overlapping gratings, thereby reducing the loss of virtual images.

Optionally, the projections of the above-mentioned multiple first outcoupling grating units 804a in the second direction of the target plane do not overlap, and the second direction is to diffract the light of the first optical characteristic with the multiple first outcoupling grating units 804a and coupled out to the direction perpendicular to the human eye, the sharp angle between the target plane and the surface away from the human eye on the optical waveguide 803 is smaller than the threshold, or the target plane is the surface away from or close to the human eye on the optical waveguide 803; multiple first The projections of the two outcoupling grating units 804b in the second direction of the target plane do not overlap. In this possible implementation, it is possible to prevent the light in the second direction from being diffracted by the previous grating unit, that is, all the light in the light beam is coupled out of the grating unit to be diffracted and coupled out to the human eye for imaging, avoiding the virtual image due to Missing or darkened images due to occlusion.

Optionally, the display device module in this embodiment of the present application may also include a fixing system, which may include a housing, a supporting surface, connectors, V-shaped grooves, and other mechanical structures, or materials for fixing or connecting.

In this embodiment, various components included in the display device module can be fixed at corresponding positions through setting of the fixing system. For example, the fixing system may include a supporting surface and a shell of the head-mounted display device, and the side of the image engine 801 facing away from the light-emitting surface may be the supporting surface, and the image engine 801 may communicate with the head-mounted display device through the above-mentioned supporting surface. The housing is fixedly connected.

Optionally, the diffraction grating (the first outcoupling grating unit, the second outcoupling grating unit, etc.) in the embodiment of the present application can be set to 100% diffraction (the diffraction efficiency of the actually processed grating may not reach 100%, here only Design goals). For example: the plurality of first outcoupling grating units 804a are specifically configured to fully diffract the light of the first optical characteristic in the light beam and couple out the fully diffracted light. The plurality of first outcoupling grating units 804b are specifically configured to perform total diffraction on the light of the second optical characteristic in the light beam and couple out the fully diffracted light. This way, compared with the diffraction grating that collects semi-reflection and semi-transmission in the prior art, can improve the utilization rate of light energy.

In this embodiment, on the one hand, the display device module completes differential diffraction control through the outcoupling grating units with different functions, and then realizes, for example, the decomposition and combination of large viewing angles, the display of images with different depths, and the display of color images. display etc. On the other hand, compared with the monolithic grating structure in the prior art, the multiple outcoupling grating units are more flexible, and the etching process is relatively simple, without multiple etching or multiple exposures. On the other hand, by setting the grating unit as a grating with nearly 100% diffraction efficiency, compared with the diffraction grating that collects semi-reflection and semi-transmission in the prior art, the utilization rate of light energy can be improved.

The structure of the display device module in the embodiment of the present application has been introduced above. In the following, only the display device module includes two or three types of outcoupling grating arrays for each of the light beams according to the incident angle, wavelength, and polarization state of the light beam. The selective and differential modulation of light with optical properties will be described as an example.

Please refer to Fig. 12 to Fig. 14, which are the outcoupling gratings in the display device module provided by the embodiment of the present application. The structure of the outcoupling grating has been introduced in Fig. 8 to Fig. 11, and the realization of Fig. 12 to Fig. 14 is as follows The virtual image imaging of different depths, the virtual image imaging of a larger field of view and the imaging of color images are described.

As shown in FIG. 12 and FIG. 13 , optionally, the first optical characteristic and the second optical characteristic are polarization state or polarization direction of light as an example. The image light incident and coupled out of the grating 804 includes image light 101a in a first polarization direction and image light 101b in a second polarization direction, and the first polarization direction and the second polarization direction are orthogonal. The grating units in the plurality of first outcoupling grating units 804a are designed and processed to only diffract incident light in the first polarization direction, and have a first diopter, and do not diffract (for example, transmit) incident light in the second polarization direction; The grating units of the plurality of second outcoupling grating units 804b are designed and processed to only diffract incident light in the second polarization direction and have a second diopter, and not diffract (eg transmit) incident light in the first polarization direction. The image light emitted by the image engine 801 is collimated and then coupled into the grating 802 into the optical waveguide 803 , and finally enters and couples out of the grating 804 in the optical waveguide 803 . Because the multiple first outcoupling grating units 804a have the first diopter for the image light 101a in the first polarization direction, the image light 101a in the first polarization direction is imaged at the first image depth after being diffracted; meanwhile, because the multiple second coupling The output grating unit 804b has a second diopter for the image light 101b in the second polarization direction, and the image light 101b in the second polarization direction is imaged at the second image depth after being diffracted. In this way, through the diffractive optical waveguide 803 , the human eyes can see images of two depths at the same time. It can be understood that the above two types of grating arrays are just examples, and the display device module provided in the present application may also include more grating arrays, so as to realize image display with more depth. Wherein, the first depth and the second depth are embodied based on the same position. For example, in the case that the display device module is applied to a head-mounted AR device, it may be based on the human eye position when the user wears the AR device correctly.

Exemplarily, for the case where the outcoupling grating is a volume holographic grating, a beam of parallel light and a beam of spherical converging light can interfere on the surface of the photopolymer, and a stable interference structure will be formed on the photopolymer, namely Volume Holographic Grating. Then, if parallel light is used to irradiate the grating, it will become converging spherical waves. During processing, spherical waves of different converging degrees and parallel light are used for interference to obtain gratings of different diopters.

In this way, compared with the consistent diopter provided by the monolithic continuous grating in the prior art, which can only display images at a single depth, the display device module provided in the embodiment of the present application can display images at multiple depths.

Optionally, the display device module provided in this application further includes a third outcoupling grating array 804c, which is used to diffract the light of the third optical characteristic in the light beam and outcouple it to the human eye for imaging, For example, the first optical characteristic, the second optical characteristic and the third optical characteristic are wavelengths of light. A plurality of first outcoupling grating units 804a, a plurality of second outcoupling grating units 804b, and a third outcoupling grating array 804c are alternately distributed.

Exemplarily, as shown in FIG. 14, the outcoupling grating 804 includes three types of outcoupling grating units: a plurality of first outcoupling grating units 804a, a plurality of second outcoupling grating units 804b, and a third outcoupling grating unit 804c (also can be referred to as the third outcoupling grating array), the light beam (or image light) incident on the outcoupling grating 804 includes the image light 101a of the first wavelength (such as the wavelength of red light), the second wavelength (such as the green light) The image light 101b of the wavelength of light) and the image light 101c of the third wavelength (for example, the wavelength of blue light). The multiple first outcoupling grating units 804a diffract the red light in the light beam and couple it out to human eyes for imaging. The multiple second outcoupling grating units 804b diffract the green light in the light beam and couple it out to human eyes for imaging. The third outcoupling grating array 804c diffracts the blue light in the light beam and couples it out to the human eye for imaging. In other words, the three types of outcoupling grating arrays diffract out the incident light in the red, green, and blue wavelength ranges respectively, and the output three-color images are synthesized into a color image to realize color display.

In this way, compared with the existing diffractive optical waveguide technology, because the diffraction grating has wavelength selectivity, one grating only modulates the incident light within a narrower wavelength range. To achieve color display, multi-layer gratings are usually required Or multi-layer optical waveguide, respectively modulates the red, green, and blue incident light, and finally merges to form a color image. Multi-layer gratings or multi-layer optical waveguides will lead to a significant decrease in the light transmittance of the optical combiner lens to the incident light from the outside world, as well as problems such as thicker optical combiner lenses and heavier weight, which will reduce the wearing experience. However, the display device module provided in the embodiment of the present application realizes the display of color images by means of three grating arrays. And due to the use of single-layer optical waveguide, single-layer outcoupling grating, and the staggered distribution of multiple outcoupling grating arrays in the outcoupling grating, there are gaps between each outcoupling grating unit, which can improve the light transmittance of the real environment and reduce Due to the thickness of the lens brought by the multilayer optical waveguide or the multilayer outcoupling grating, the weight of the module is reduced, and then applied to the wearable device provided by the embodiment of the present application, the wearing experience of the user can be improved.

A situation in which the display device module may further include a coupling-in grating 802 will be described in detail below. The in-coupling grating 802 includes a plurality of first in-coupling grating units and a plurality of second in-coupling grating units. A plurality of first coupling-in grating units are used to receive the light beam emitted by the image engine 801, diffract the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and transmit the light of the first optical characteristic to the optical waveguide 803 The optical waveguide 803 is specifically used to totally reflect the light of the first optical feature and propagate to a plurality of first outcoupling grating units 804a; a plurality of second incoupling grating units are used to receive the light beam emitted by the image engine 801, and The light of the fifth optical characteristic in the light beam is diffracted into the light of the second optical characteristic, and the light of the second optical characteristic is transmitted to the optical waveguide 803; the optical waveguide 803 is specifically used for total reflection and propagation of the light of the second optical characteristic to a plurality of second outcoupling grating units 804b. The third polarization state of the light corresponding to the fourth optical characteristic is different from the fourth polarization state of the light corresponding to the fifth optical characteristic, or, the third incident angle of the light corresponding to the fourth optical characteristic is different from that of the light corresponding to the fifth optical characteristic The fourth angle of incidence is different.

In order to make the in-coupling grating 802 diffract the light, two parts of light with uniform light energy can be obtained. The aforementioned multiple first coupling-in grating units have the same area and are uniformly distributed, and the multiple second coupling-in grating units have the same area and are uniformly distributed. Even distribution can be understood as meaning that the distance between two adjacent coupling-in grating units is the same in a certain direction on the plane where the multiple first coupling-in grating units and the multiple second coupling-in grating units are located. Even distribution can also be understood as a close arrangement of multiple first coupling grating units and multiple second coupling grating units. Wherein, the distance between two adjacent coupling-in grating units can be understood as the distance between the center points of two adjacent coupling-in grating units. Of course, this distance is only described by the center point of the grating unit, and it can also be The distance is calculated by means of the same side of the grating unit or the same reference point, etc., which is not limited here.

In this way, the display device module can decompose the large FOV coupled into the grating 802 projected by the image engine 801 onto the optical waveguide 803 into multiple small FOVs, which are modulated and transmitted independently in different propagation directions. That is, by utilizing the feature that different grating arrays can selectively respond to light rays in different incident angle ranges, the image light incident to the outcoupling grating 804 in different incident angle ranges (corresponding to different sub-FOVs of the same complete image FOV respectively) can be Remodulation is integrated into a complete large FOV outcoupling optical waveguide 803 .

The plurality of first outcoupling grating units 804a in the outcoupling grating 804 respond to the first subfield of view light 801a, but do not respond to the second subfield of view light 801b (because the plurality of first outcoupling grating units 804a respond to the first optical field of view light 801a characteristic light is diffracted). Correspondingly, the plurality of second outcoupling grating units 804b in the outcoupling grating 804 respond to the second subfield of view light 801b, but do not respond to the first subfield of view light 801a (because the plurality of second outcoupling grating units 804b respond to light of the second optical characteristic is diffracted). Through the design of the exit directions of the diffracted light of multiple first outcoupling grating units 804a and multiple second outcoupling grating units 804b, the outcoupling grating 804 can couple the light from the two sub-fields of view out of the optical waveguide 803 and combine them to form a complete field of view. field, so that human eyes can see the complete large field of view image projected by the image engine 801 onto the optical waveguide 803 .

Optionally, the display device module may further include a turning grating, and the turning grating is located between the incoupling grating 802 and the outcoupling grating 804 . The refraction grating may also include a plurality of first refraction grating units (or called a first refraction grating array) and a plurality of second refraction grating units (or a second refraction grating array). The first refraction grating array is used to receive the light diffracted by the multiple first in-coupling grating units, and diffract the light diffracted by the multiple first in-coupling grating units to the first out-coupling grating array. The second deflection grating array is used to receive the light diffracted by the multiple second in-coupling grating units, and diffract the light diffracted by the multiple second in-coupling grating units to the second out-coupling grating array.

Exemplarily, as shown in FIG. 15 , the coupling grating 802 includes a plurality of first coupling grating units 802a and a plurality of second coupling grating units 802b. The turning grating includes a first turning grating array 805a and a second turning grating array 805b. The outcoupling grating 804 includes a plurality of first outcoupling grating units 804a and a plurality of second outcoupling grating units 804b. The specific projection process can be as follows:

After the light emitted by the image engine 801 is collimated by the lens (or the in-coupling grating 802 ), the collimated image light forms an image light field of view and enters the in-coupling grating 802 . The coupling grating 802 divides the incident light into two parts according to the incident angle, the image light 801a belonging to the first sub-field of view and the image light 802b belonging to the second sub-field of view, the first sub-field of view and the second sub-field of view can be partially overlap, and together form the complete field of view of the image source. The in-coupling grating 802 includes two groups of grating arrays, that is, a plurality of first in-coupling grating units and a plurality of second in-coupling grating units. The light in the second part of the field of view 801b does not respond. The plurality of second coupling-in grating units respond to the light of the second sub-field of view 801b, but do not respond to the light of the first sub-field of view 801a. Therefore, the in-coupling grating 802 diffracts the first sub-field of view light 801a toward the direction of the first turning grating array 805a through a plurality of first in-coupling grating units, and diffracts the second sub-field of view light 801a through a plurality of second in-coupling grating units. 801b diffracts toward the direction of the second deflection grating array 805b. That is, the image light projected onto the coupling-in grating 802 is decomposed into two propagation directions by the two grating arrays according to the different incident angles, so that the complete FOV of the image light projected onto the coupling-in grating 802 is decomposed into two sub-FOVs, Propagate independently in two different directions.

The two kinds of turning grating arrays 805a and 805b respectively expand the pupils of the two sub-fields of view rays propagating in the optical waveguide 803 in the horizontal direction, and at the same time guide them to the direction of coupling out the grating 804 through diffraction, so that the light rays belonging to the two sub-fields of view are incident The incident angle range of the outcoupling grating 804 is different.

It can be understood that, the above-mentioned scheme of decomposing, independently transmitting and recombining the projected FOV of the display device through the coupling gratings of two types of grating arrays and the coupling out gratings of two types of grating arrays is only an example of implementation, and can be implemented in practical applications. Using more grating arrays with in-coupling gratings and out-coupling gratings, the FOV is decomposed into more sub-FOVs that are independently transmitted in the waveguide and then recombined to achieve a larger image FOV display.

Optionally, if the outcoupling grating and the incoupling grating are volume holographic gratings, the multiple first incoupling grating units that diffract the first incident angle range are obtained by interference of two beams of light during design. The first incident angle range is related to the interference position of the light beam.

Compared with the existing technology, in order to support a large FOV, the outcoupling grating adopts angle multiplexing technology such as repeated etching or multiple exposures for FOV splicing, resulting in a serious drop in diffraction efficiency, and the image light leaks out of the lens, resulting in "lens light leakage" , also affects the utilization efficiency of image light. The outcoupling grating in the embodiment of the present application includes multiple functions of the outcoupling grating array, and one function of the outcoupling grating array can be etched or exposed once to achieve a larger image FOV display.

In addition, in order that the display module device can improve the distribution uniformity of light energy in the eyebox and FOV, the embodiment of the present application also provides several other display device modules, which will be described in detail below.

An embodiment:

Please refer to a and c in FIG. 16 , the display device module includes: an image engine 801 , an in-coupling grating 802 , an optical waveguide 803 and an out-coupling grating 804 . Wherein, the outcoupling grating 804 includes a plurality of outcoupling grating units, and the plurality of outcoupling grating units include at least two outcoupling grating units distributed in the first direction, and the farther the at least two outcoupling grating units are from the image engine 801 The higher the coverage per unit area of the outcoupling grating unit, the first direction is the direction from close to the image engine 801 to away from the image engine 801; the optical waveguide 803 is used to receive the light beam from the image engine 801, and is fixed on the optical waveguide 803 The coupling-in grating 802 redirects the light beam to obtain the image light 801a, and propagates the image light 801a to multiple out-coupling grating units; the multiple out-coupling grating units are fixed on the optical waveguide 803, and the multiple out-coupling grating units are used for the optical waveguide The image light 801a propagating in 803 is diffracted and the diffracted light is coupled out.

Wherein, the coverage per unit area can be understood as: the duty ratio of the grating unit in the unit area, or the ratio of the area of the grating unit in the unit area to the total area of the unit area. In the first direction, the farther away from the image engine 801 the higher the coverage per unit area of the first outcoupling grating unit can be understood as: in the first direction, select two areas with the same area, wherein the distance from the image engine 801 The coverage (duty ratio) of the first outcoupling grating unit in the farther region is larger. In order to realize the higher coverage per unit area of the first outcoupling grating unit farther away from the image engine 801 in the first direction, possible implementation methods include: in the first direction, each grating unit has the same area, within a unit area The density of raster elements is increased. Alternatively, the density of the grating units in a unit area remains unchanged, and the area of each grating unit increases. It can be understood that the above two ways are just examples. In practical applications, there may be other ways to make the coverage per unit area of the first outcoupling grating unit farther away from the image engine 801 higher, which is not specifically limited here. .

Exemplarily, c in FIG. 16 shows a structural form in which the farther away from the image engine 801 the first outcoupling grating unit has a higher coverage per unit area.

In this embodiment, a small-area grating unit is first incident on the image light 801a, and a grating unit with a gradually increasing area is incident on the later stage. By adjusting the area of each grating unit, the distribution of light energy in the exit pupil area can be more fine-grained. It can be adjusted in a precise manner, and at the same time realize high utilization rate of incident light energy and avoid loss of light energy.

Another example:

Please refer to a and b in Fig. 16, the image light 801a passes through the coupling grating and the turning grating on the optical waveguide 803 (in the partially diffractive optical waveguide structure, the turning grating may not be used, the light is coupled into the optical waveguide from the coupling grating, Directly guide the outcoupling grating) into the waveguide region where the outcoupling grating 804 is located, where the outcoupling grating 804 will be incident multiple times, each time only part of the light energy will be coupled out of the waveguide, so as to pass from the adjacent image engine to the far away image The pupil dilation is performed in the direction of the engine.

Wherein, the outcoupling grating 804 includes N subregions, each of the N subregions includes a plurality of outcoupling grating units, and the total area of the outcoupling grating units included in each subregion along the first direction is within each The proportion of the area of the sub-region increases gradually, and N is a positive integer greater than 1. By adjusting the spatial distribution density of each grating unit in the N subregions of the outcoupling grating 804, the duty cycle of the grating at different positions in the outcoupling grating area is controlled, thereby controlling the uniform distribution of the light energy coupled out of the optical waveguide 803 in the entire Eyebox.

As shown in b in FIG. 16 , the following description will be made by taking N as 3 and the grating units in each region having the same area as an example. The outcoupling grating 804 includes three regions, namely a first region 804a, a second region 804b and a third region 804c. The number of grating elements in each area can gradually increase in the propagation direction of the light beam. In the first region 804a, the distribution density of the grating units is the smallest, and the total area of the grating units in the first region 804a accounts for 1/3 of the area of the first region 804a. In the second region 804b, the distribution density of the grating units increases, and the total area of the grating units accounts for 50% of the area of the second region 804b. In the third area 804c, the total area of the grating units accounts for 100% of the area of the third area 804c (in this case, the third area 804c can also be replaced by a whole piece of grating covering the third area 804c). When the light 801a propagating in the optical waveguide 803 propagates to the first region 804a, 1/3 of the light energy is diffracted, and the remaining 2/3 of the light energy continues to propagate to the second region 804b, and 1/2 ( That is, 1/3 of the total light energy incident on the outcoupling grating 804) is diffracted by the grating unit in the second region 804b, and the remaining light energy (accounting for 1/3 of the total light energy incident on the outcoupling grating 804) continues to propagate to the third The region 804c is 100% diffracted at the third region 804c (the diffraction efficiency of the actually processed grating may not reach 100%, which is only a design goal here). In this way, the light intensity of the diffracted light in the three areas coupled out of the grating 804 accounts for 1/3 of the total incident light intensity, the light intensity is evenly distributed, and all the light intensity is fully utilized, and the light energy utilization rate of the grating is high. It should be pointed out that in Fig. 16, the outcoupling grating 804 is divided into three areas with different distribution densities, which is just an example. In actual applications, the number of areas can be increased or decreased according to the needs, and more density areas can be divided into the eyebox. The distribution of light energy achieves finer-grained regulation.

Optionally, the outcoupling grating 804 is used to fully diffract all the light in the light beam propagating in the optical waveguide and outcouple it to the human eye for imaging. Among them, full diffraction can be understood as not semi-reflective and semi-transmissive. In this way, all the light in the light beam can be fully diffracted, thereby improving the utilization rate of light energy.

It can be understood that the display device module in this embodiment may also include an in-coupling grating and a turning grating, and the turning grating may be similar to the out-coupling grating 804 in FIG. 16 . That is, the image light 801a emitted by the display device outside the optical waveguide 803 is coupled into the optical waveguide 903 through the coupling grating, and propagates through the optical waveguide 803 to the turning grating. The turning grating can adopt the design of the aforementioned outcoupling grating 804 to control the ratio of the light energy diffracted each time to the total incident light energy when the image light 801a is diffracted multiple times in the propagation direction, so that the light energy is evenly coupled from the outcoupling grating 804. output, thereby ensuring the uniformity of light energy distribution in the eyebox and FOV.

Please refer to FIG. 17 , an embodiment of another display device module provided by the present application, which can realize uniform distribution of light energy in the eyebox and in the FOV.

The display device module includes: an optical waveguide and multiple outcoupling grating units, the optical waveguide is used to receive light beams from the image engine, and transmit light beams to the multiple outcoupling grating units; the multiple outcoupling grating units are fixed on the optical waveguide, A plurality of outcoupling grating units is used to diffract the beam propagating in the optical waveguide and couple it out to the human eye for imaging; a plurality of outcoupling grating units are arranged in an array in the first direction and the second direction on the target plane, the second The first direction is not perpendicular to the second direction, the sharp angle between the target plane and the surface of the optical waveguide away from the human eye is smaller than a threshold, or the target plane is the surface of the optical waveguide away from or close to the human eye.

Optionally, a plurality of outcoupling grating units are used to fully diffract all the light in the light beam propagating in the optical waveguide and outcouple it to the human eye for imaging. Among them, full diffraction can be understood as not semi-reflective and semi-transmissive. In this way, all the light in the light beam can be fully diffracted, thereby improving the utilization rate of light energy.

Exemplarily, as shown in a of FIG. 17 , the signal light emitted by the image engine 801 is modulated by the coupling grating 802 on the upper surface of the optical waveguide 803 and then collimated. reflection propagation. Multiple outcoupling gratings 804 placed obliquely are embedded in the optical waveguide 803 . A plurality of outcoupling gratings 804 are used to couple out the signal light propagating in the optical waveguide 803 out of the optical waveguide 803. The signal light propagating in the optical waveguide 803 will contact the outcoupling grating 804, be modulated by multiple outcoupling gratings 804, reflect out of the optical waveguide 803, and exit to the exit pupil position 805, when the human eye is located at the exit pupil position 805 , the virtual image light and the real scene light 806 are received at the same time, and the virtual image and the real scene can be seen at the same time.

Optionally, a plurality of outcoupling grating units are distributed in a plurality of outcoupling gratings 804, and each outcoupling grating 804 includes a part of outcoupling grating units in the plurality of outcoupling grating units; the plurality of outcoupling gratings 804 are fixedly embedded in the light In the waveguide 803, one side of the multiple outcoupling gratings 804 is in contact with the surface of the optical waveguide 803 away from the human eye, and the other side of the multiple outcoupling gratings 804 is in contact with the surface of the optical waveguide 803 close to the human eye. Each outcoupling grating 804 includes a part of outcoupling grating units in the plurality of outcoupling grating units.

Exemplarily, b in FIG. 17 is a three-view view of the optical waveguide 803, and the multiple outcoupling gratings 804 in the optical waveguide 803 adopt a distributed grating array. It can be seen from the front view that each grating unit is approximately uniformly distributed in the two-dimensional space of the waveguide plane; The projections on the orthogonal direction to the light propagation direction) are closely arranged, but do not overlap and block each other. Or it can be understood that each outcoupling grating unit in the outcoupling grating is arranged in an array on the first direction and the second direction of the target plane, the first direction and the second direction are not perpendicular, and the target plane and the optical waveguide 803 are far away from people. The sharp angle between the surfaces of the eyes is less than a threshold, or the target plane is a surface on the optical waveguide 803 that is far away from or close to the human eyes. The spatial arrangement of the multiple outcoupling gratings 804, on the one hand, enables the image light to pass through one diffraction in the direction of propagation, and be evenly outcoupled by energy. Before the image light reaches the lower edge of the optical waveguide 803, it will be incident on a certain grating unit and be diffracted out of the optical waveguide 803, so that the utilization rate of light energy is high. Furthermore, the display device module can realize high utilization rate of light energy and uniform distribution of outcoupled light energy in eyebox and FOV. In addition, each grating unit is embedded in the optical waveguide 803 and placed obliquely. The grating units are sparsely arranged in the direction of the user's visual axis, which has minimal interference with the light of the real scene outside. The optical waveguide 803 has better ambient light transmittance.

The terms "first", "second" and the like in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and are not necessarily used to describe a specific sequence or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, and this is merely a description of the manner in which objects with the same attribute are described in the embodiments of the present application. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, so that a product or device comprising a series of elements is not necessarily limited to those elements, but may include items not expressly listed or for other units inherent in these products or equipment.

Although the application has been described in conjunction with specific features and embodiments thereof, it will be apparent that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and drawings are merely illustrative of the application as defined by the appended claims and are deemed to cover any and all modifications, variations, combinations or equivalents within the scope of this application.

Obviously, those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope of the application. In this way, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims (26)

A display device module, characterized in that it includes an optical waveguide, a plurality of first outcoupling grating units and a plurality of second outcoupling grating units, the plurality of first outcoupling grating units are fixed to the optical waveguide, The plurality of second outcoupling grating units are fixed to the optical waveguide, and the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are distributed alternately; The optical waveguide is used to receive the light beam from the image engine, and transmit the light beam to the plurality of first outcoupling grating units and the plurality of second outcoupling grating units; The multiple first outcoupling grating units are configured to diffract the light of the first optical characteristic in the light beam and couple out the diffracted light; The plurality of second outcoupling grating units are configured to diffract the light of the second optical characteristic in the light beam and couple out the diffracted light, the first optical characteristic and the second optical characteristic are different. The display device module according to claim 1, wherein the first optical characteristic and the second optical characteristic are different, comprising: The first wavelength of light corresponding to the first optical characteristic is different from the second wavelength of light corresponding to the second optical characteristic; or, The first polarization state of the light corresponding to the first optical characteristic is different from the second polarization state of the light corresponding to the second optical characteristic; or, A first incident angle of light corresponding to the first optical characteristic is different from a second incident angle of light corresponding to the second optical characteristic. The display device module according to claim 1 or 2, wherein the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are distributed alternately on the same plane. The display device module according to claim 1 or 2, wherein the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are respectively fixedly embedded in the optical waveguide, so The plurality of first outcoupling grating units and the plurality of second outcoupling grating units are not on the same plane. The display device module according to any one of claims 1 to 4, characterized in that, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are fixed on the side of the optical waveguide Surface or fixed embedded inside the optical waveguide. The display device module according to any one of claims 1 to 5, wherein the incident angle and the outgoing angle of the light of the first characteristic on the plurality of second outcoupling grating units are the same, so The incident angle and the outgoing angle of the light of the second characteristic on the plurality of first outcoupling grating units are the same. The display device module according to any one of claims 1 to 6, wherein the plurality of first outcoupling grating units adopt a first diopter to diffract the light of the first optical characteristic, and the The plurality of second outcoupling grating units diffract the light of the second optical characteristic with a second diopter, the first diopter being different from the second diopter. The display device module according to any one of claims 1 to 7, characterized in that the image depth of the image formed by the light beam diffracted by the plurality of first outcoupling grating units is the first depth, and the imaging depth of the image through the plurality of outcoupling grating units is the first depth. The imaging depth of the light beam diffracted by the second outcoupling grating unit is a second depth, and the first depth is different from the second depth. The display device module according to any one of claims 1 to 8, wherein the first optical characteristic is the wavelength of red light, the second optical characteristic is the wavelength of green light, and the display device The module also includes a plurality of third outcoupling grating units, and the plurality of third outcoupling grating units are fixed to the optical waveguide; The plurality of third outcoupling grating units are configured to diffract light of a third optical characteristic in the light beam and couple out the diffracted light, the third optical characteristic being the wavelength of blue light. The display device module according to any one of claims 1 to 9, wherein the display device module further comprises a plurality of first coupling grating units and a plurality of second coupling grating units, the The plurality of first coupling grating units and the plurality of second coupling grating units are fixed to the optical waveguide, and the plurality of first coupling grating units and the plurality of second coupling grating units are distributed in a staggered manner; The multiple first coupling-in grating units are used to receive the light beam emitted by the image engine, diffract the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and convert the light of the first optical characteristic into light of the first optical characteristic. optically characteristic light is transmitted to the optical waveguide; The multiple second coupling-in grating units are used to receive the light beam emitted by the image engine, diffract light of the fifth optical characteristic in the light beam into light of the second optical characteristic, and convert the light of the second optical characteristic into light of the second optical characteristic. The light of the optical characteristic is transmitted to the optical waveguide; the third polarization state of the light corresponding to the fourth optical characteristic is different from the fourth polarization state of the light corresponding to the fifth optical characteristic, or the fourth optical characteristic The corresponding third incident angle of light is different from the fourth incident angle of light corresponding to the fifth optical characteristic. The display device module according to any one of claims 1 to 9, wherein the display device module further comprises a plurality of first coupling grating units and a plurality of second coupling grating units, the The plurality of first coupling grating units and the plurality of second coupling grating units are fixed to the optical waveguide, and the plurality of first coupling grating units and the plurality of second coupling grating units are distributed in a staggered manner; The multiple first coupling-in grating units are used to receive the light beam emitted by the image engine, diffract the light of the first optical characteristic in the light beam, and diffract the light of the first optical characteristic transmitted to said optical waveguide; The multiple second coupling grating units are used to receive the light beam emitted by the image engine, and to diffract the light of the second optical characteristic in the light beam, and to diffract the light of the second optical characteristic light is transmitted to the optical waveguide; The first wavelength of light corresponding to the first optical characteristic is different from the second wavelength of light corresponding to the second optical characteristic. The display device module according to claim 10 or 11, wherein the areas of the plurality of first coupling-in grating units are the same and uniformly distributed, and the areas of the plurality of second coupling-in grating units are the same and uniform distributed. The display device module according to any one of claims 1 to 12, wherein the plurality of first outcoupling grating units include at least two first outcoupling grating units distributed in the first direction, Among the at least two first outcoupling grating units, the farther the first outcoupling grating unit is from the image engine, the higher the coverage per unit area, and the first direction is from close to the image engine to far away from the image engine. The orientation of the graphics engine. The display device module according to any one of claims 1 to 13, wherein the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are reflective diffraction gratings, so The plurality of first outcoupling grating units and the plurality of second outcoupling grating units are fixed on the surface of the optical waveguide opposite to the light emitting surface of the optical waveguide, or the plurality of first outcoupling grating units The multiple second outcoupling grating units are fixedly embedded in the optical waveguide. The display device module according to any one of claims 1 to 14, wherein the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are transmissive diffraction gratings, so The plurality of first outcoupling grating units and the plurality of second outcoupling grating units are fixed on the light emitting surface of the optical waveguide. The display device module according to any one of claims 1 to 15, wherein the optical waveguide, the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are also used to transmit ambient light. A display device module, characterized in that it includes an optical waveguide and a plurality of outcoupling grating units, the optical waveguide is used to receive light beams from an image engine, and transmit the light beams to the plurality of outcoupling grating units; The plurality of outcoupling grating units are fixed on the optical waveguide, and the plurality of outcoupling grating units are used to diffract the light beam propagating in the optical waveguide and couple out the diffracted light; The multiple outcoupling grating units are arranged in an array in the first direction and the second direction on the target plane, the first direction and the second direction are not perpendicular, and the target plane and the optical waveguide The acute included angle between the light-emitting surfaces is smaller than a threshold, or the target plane is the light-emitting surface or a surface on the optical waveguide opposite to the light-emitting surface. The display device module according to claim 17, wherein the plurality of outcoupling grating units are distributed among a plurality of outcoupling gratings, and each of the outcoupling gratings includes one of the plurality of outcoupling grating units. A partial outcoupling grating unit; one side of the plurality of outcoupling gratings is in contact with the surface of the optical waveguide opposite to the light output surface, and the other side of the plurality of outcoupling gratings is in contact with the light output surface. A display device, characterized by comprising: an image engine and a display module; The image engine is used to emit light beams; The display module includes the display device module according to any one of claims 1-18. A display device, the display device is an augmented reality AR device or a mixed reality MR device, characterized in that it includes: a left-eye display module, a right-eye display module, a middle case, and a temple; The middle case is used to fix the left-eye display module, the right-eye display module and the temples, the left-eye display module and/or the right-eye display module includes The display device module described in any one of 18 to 18. An image display method, characterized in that the method is applied to a display device module, the display device module includes an optical waveguide, a plurality of first outcoupling grating units, and a plurality of second outcoupling grating units, the A plurality of first outcoupling grating units are fixed to the optical waveguide, and the plurality of second outcoupling grating units are fixed to the optical waveguide, and the plurality of first outcoupling grating units and the plurality of second outcoupling grating units are fixed to the optical waveguide. The outcoupling grating units are staggered; The optical waveguide receives the light beam from the image engine, and transmits the light beam to the plurality of first outcoupling grating units and the plurality of second outcoupling grating units; The plurality of first outcoupling grating units diffract the light of the first optical characteristic in the light beam and couple out the diffracted light; The plurality of second outcoupling grating units diffract the light of the second optical characteristic in the light beam and couple out the diffracted light, the first optical characteristic and the second optical characteristic are different. The method of claim 21, wherein the first optical characteristic and the second optical characteristic are different, comprising: The first wavelength of light corresponding to the first optical characteristic is different from the second wavelength of light corresponding to the second optical characteristic; or, The first polarization state of the light corresponding to the first optical characteristic is different from the second polarization state of the light corresponding to the second optical characteristic; or, A first incident angle of light corresponding to the first optical characteristic is different from a second incident angle of light corresponding to the second optical characteristic. The method according to claim 21 or 22, wherein the display device module further comprises a plurality of first coupling grating units and a plurality of second coupling grating units, and the plurality of first coupling grating units The unit and the plurality of second coupling grating units are fixed to the optical waveguide, and the plurality of first coupling grating units and the plurality of second coupling grating units are distributed alternately; The multiple first coupling-in grating units receive the light beam emitted by the image engine, diffract the light of the fourth optical characteristic in the light beam into the light of the first optical characteristic, and convert the light of the first optical characteristic into light of the first optical characteristic light is transmitted to the optical waveguide; The multiple second coupling-in grating units receive the light beam emitted by the image engine, diffract the light of the fifth optical characteristic in the light beam into the light of the second optical characteristic, and convert the light of the second optical characteristic into light of the second optical characteristic The light is transmitted to the optical waveguide; the third polarization state of the light corresponding to the fourth optical characteristic is different from the fourth polarization state of the light corresponding to the fifth optical characteristic, or, the light corresponding to the fourth optical characteristic The third incident angle of the light corresponding to the fifth optical characteristic is different from the fourth incident angle of the light corresponding to the fifth optical characteristic. The method according to any one of claims 21 to 23, wherein the plurality of first outcoupling grating units adopt a first diopter to diffract the light of the first optical characteristic, and the plurality of first outcoupling grating units The second outcoupling grating unit diffracts the light of the second optical characteristic with a second diopter, and the first diopter is different from the second diopter. The method according to any one of claims 21 to 24, wherein the imaging depth of the light beams diffracted by the plurality of first outcoupling grating units is the first depth, The imaging depth of the light beam diffracted by the grating unit is a second depth, and the first depth is different from the second depth. The method according to any one of claims 21 to 25, wherein the first optical characteristic is the wavelength of red light, the second optical characteristic is the wavelength of green light, and the display device module further comprising a plurality of third outcoupling grating units, the plurality of third outcoupling grating units being fixed to the optical waveguide; The plurality of third outcoupling grating units diffracts the light of the third optical characteristic in the light beam and couples out the diffracted light, the third optical characteristic being the wavelength of blue light.

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