CN201159778Y - Light guide plate and side light type backlight module with same - Google Patents

Abstract

A light guide plate and a side-light type backlight module with the light guide plate are provided, wherein the light guide plate comprises a transparent substrate, a plurality of prisms and a plurality of condensing lenses. The plurality of prisms are arranged side by side on a face of the transparent substrate. The plurality of condensing lenses are arranged between every two adjacent prisms and distributed from sparse to dense along the ridge line direction of the prisms.

Description

Light guide plate and side-light backlight module with the light guide plate

technical field

The utility model relates to a light guide plate and a side-light backlight module with the light guide plate, in particular to a light guide plate with a microstructure and a side-light backlight module with the light guide plate.

Background technique

The light guide plate is an important part that affects the light efficiency of the edge-lit backlight module. The light guide plate is applied to the side-lit backlight module, which can convert the light emitted by the point light source or line light source into a uniform surface light source, and then improve the surface light source through the uniform light effect of the diffuser and the light concentration effect of the brightness enhancement film. uniformity and brightness. The light guide plate is divided into wedge-shaped plate and flat plate in terms of appearance. Generally, notebook computers use wedge-shaped plates due to consideration of the space relationship, while LCD monitors (LCD Monitor) and LCD TVs (LCD TV) mainly use flat-panel plates.

FIG. 1A is a schematic diagram of an edge-lit backlight module 100 with a conventional light guide plate. The edge-lit backlight module 100 includes a light guide plate 120 , a light source 140 , a brightness enhancement film 160 and a diffusion film 180 . The body of the light guide plate 120 is a wedge-shaped light-transmitting plate, and its main function is to guide the direction of light to improve the luminance of the liquid crystal panel and control the uniformity of luminance. The wedge-shaped light guide plate 120 generally has a thick end surface 122 , a thin end surface 124 , a bottom surface 126 and a top surface 128 . During the assembly process of the edge-lit backlight module 100 , the bottom surface 126 of the light guide plate 120 is usually facing downwards, and the top surface 128 is facing upwards, and optical films such as the brightness enhancement film 160 and the diffusion film 180 are disposed above the top surface 128 . However, in this figure, the bottom surface 126 is facing upwards to illustrate the microstructure.

The bottom surface 126 of the existing light guide plate 120 forms a microstructure, such as a plurality of juxtaposed prisms 126a, or a V-cut structure. The light source 140 is generally located at the side of the thick end surface 122 of the light guide plate 120 . After most of the light enters the light guide plate 120 , it is transmitted to the thin end surface 124 by total reflection. After the light is transmitted to the prism 126 a on the bottom surface 126 of the light guide plate 120 , it will be concentrated and then emitted from the top surface 128 (as shown by the arrow). Therefore, the pattern design of the microstructure can make the light pass through the light guide plate 120 more uniform.

However, because the bottom surface 126 of the light guide plate 120 uses the prism 126a for concentrating light, when the line light source or the point light source sends light into the light guide plate 120, the light incident side of the light guide plate 120 will have a significant difference due to the concentrated light. For the phenomenon of alternating light and dark, please refer to FIG. 1B and FIG. 1C. FIG. 1B shows the distribution of the bright lines 102 of the edge-type backlight module 100 when the light source 140 is a cold cathode ray tube 140a, and FIG. 1C shows the bright halo of the edge-type backlight module 100 when the light source 140 is composed of light-emitting diodes 140b. The distribution of 104. In current high-brightness backlight modules, it is necessary to adjust the brightness variation of the backlight module to be as uniform as possible.

For the above problems, the existing solution is to make the thick end surface 122 into a matte surface, so that the light sent into the light guide plate 120 is more scattered, but this method will increase the process steps, increase the cost, and indirectly reduce the quality. rate and light use efficiency.

Utility model content

The purpose of the present invention is to provide a light guide plate with a microstructure, which can improve the optical distribution and light-gathering effect when applied in the backlight module, so as to improve the efficiency of light use and adjust the optical picture at the same time.

Other purposes and advantages of the utility model can be further understood from the technical characteristics disclosed in the utility model.

To achieve one or part or all of the above purposes or other purposes, a light guide plate according to an embodiment of the present invention includes a transparent base, a plurality of prisms, and a plurality of condensing lenses. The transparent substrate has faces. A plurality of prisms are arranged side by side on the surface of the transparent base. A plurality of condenser lenses are arranged between every two adjacent prisms, and are distributed from sparse to dense along the ridge line direction of the prisms.

An embodiment of the present invention provides a backlight module, which includes a transparent substrate, a light source, multiple prisms, and multiple condenser lenses. The transparent substrate has a bottom surface, a light exit surface and a light incident surface, and the light exit surface is opposite to the bottom surface, and the light incident surface connects the bottom surface and the light exit surface. The light source is arranged on one side of the transparent base and faces the light incident surface. A plurality of prisms protrude from the bottom surface and are arranged side by side on the bottom surface. A plurality of condenser lenses are arranged between every two adjacent prisms, and are distributed from sparse to dense along the ridgeline direction of the prisms from the light incident surface. The light emitted by the light source enters the transparent substrate from the light incident surface, converges with the condensing lens through the prism, and exits through the light exit surface.

Preferably, in the above light guide plate, the condensing lens and the transparent base are integrally formed. The part of the bottom surface of the light-transmitting base between every two adjacent prisms is a flat part, and the light-condensing lenses are distributed on the flat part. The prism has a first height, and the condenser lens has a second height, and the second height is smaller than the first height. The prisms include a first prism, a second prism and a third prism, and the part of the condensing lens between the first and second prisms and the part of the condensing lens between the second and third prisms are alternately arranged. The condenser lens is cylindrical, spherical or conical, or spherical or aspheric.

In a preferred embodiment of the above edge-lit backlight module, the direction of the ridge line of the prism is parallel to the light incident direction of the light source. The light source can be a light emitting diode.

Description of drawings

1A is a schematic diagram of an edge-lit backlight module with an existing light guide plate;

FIG. 1B is a schematic diagram of bright line distribution of a conventional backlight module;

FIG. 1C is a schematic diagram of the distribution of bright halos in an existing backlight module;

2A and 2B are schematic diagrams of a light guide plate and its microstructure according to a first embodiment of the present invention;

Fig. 2C is a schematic diagram of another implementation manner according to the first embodiment of the present invention;

3A and 3B are schematic diagrams of a light guide plate and its microstructure according to a second embodiment of the present invention;

4 is a schematic diagram of a light guide plate and its microstructure according to a third embodiment of the present invention;

FIG. 5 is a schematic diagram of an edge-lit backlight module according to an embodiment of the present invention.

Detailed ways

The aforementioned and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of preferred embodiments in conjunction with the accompanying drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only referring to the directions of the drawings. Therefore, the directional terms used are used to illustrate but not to limit the present invention.

Referring to FIG. 2A and FIG. 2B , the light guide plate 200 includes a light-transmitting base 220 and two kinds of microstructures formed on the bottom surface 222 of the light-transmitting base 220 . The two microstructures include a plurality of prisms 240 and a plurality of condenser lenses 260 . As shown in FIG. 2A , a plurality of prisms 240 are arranged side by side on the bottom surface 222 of the transparent substrate 220 . A plurality of condenser lenses 260 are disposed between every two adjacent prisms 240 , and are distributed from sparse to dense along the direction of the ridge line 242 of the prisms 240 .

2A also shows the light incident direction (as shown by the arrow). In this embodiment, the direction parallel to the light incident direction is defined as the Y direction, and the direction perpendicular to the light incident direction and parallel to the bottom surface 222 is defined as the X direction. When the light guide plate 200 is applied in an edge-lit backlight module, the direction of the ridges 242 of the prism 240 is parallel to the Y direction, so that in the X direction, light is concentrated from the ridges 242 on both sides to the center. When the side-light backlight module is installed on the back of the liquid crystal panel (not shown), the brightness of the center of the entire liquid crystal panel can be increased in the X direction. In practical applications, the prism 240 is not limited to the pointed shape in the drawings, and may also be formed with a flat portion (not shown), as long as it is a structure that can achieve the light-condensing effect. However, if the condensing lens 260 is not provided, then in the Y direction, the luminance distribution curve A shows that the luminance of the edge-lit backlight module is higher on the side closer to the light source (not shown), and the luminance decreases gradually as it is farther away from the light source.

In this embodiment, a condenser lens 260 protruding from the bottom surface 222 of the transparent substrate 220 is disposed between any two adjacent prisms 240 . At the end close to the light source in the Y direction, the condenser lenses 260 are arranged sparsely to reduce the light gathering effect of the light guide plate 200 near the light source. At the end far away from the light source in the Y direction, the condensing lenses 260 are arranged closely to increase the light condensing effect of the part of the light guide plate 200 far away from the light source. Thus, the brightness uniformity of the backlight module in the Y direction can be adjusted, as shown by the brightness distribution curve B.

Referring to FIG. 2B, a preferred embodiment of the light guide plate 200 is illustrated as follows. The portion of the bottom surface 222 of the light-transmitting substrate 220 between every two adjacent prisms 240 is a flat portion 280 , and the condenser lenses 260 are distributed on the flat portion 280 . Preferably, the prism 240, the condenser lens 260 and the light-transmitting base 220 are integrally formed, so that the manufacturing steps of the mold are more convenient and the cost of mold opening is avoided. The prism 240 protrudes from the bottom surface 222 of the transparent base 220 , and the distance between the ridge line 242 at the top and the flat portion 280 is a first height H1 . There is a second height H2 between the top of the condenser lens 260 and the flat portion 280 . The second height H2 is preferably smaller than the first height H1. In this way, the light guide plate 200 utilizes the prisms 240 for concentrating light, and then cooperates with the concentrating lenses 260 in a gradually denser distribution to adjust the brightness distribution, which can achieve the effect of concentrating light and adjusting the optical distribution.

The condenser lens 260 shown in FIG. 2A is approximately a cylinder, and its axis is along the X direction, that is, perpendicular to the ridge line 242 of the prism 240 . In practical application, the condenser lens 260 is not limited to a cylinder, and its arrangement direction can be parallel, perpendicular or oblique to the direction of the ridge line 242 of the prism 240 . The degree of density of the condenser lenses 260 on the bottom surface 222 of the entire light-transmitting substrate 220 can be locally adjusted according to the actual measured brightness distribution. In the light guide plate 200a shown in FIG. 2C , the region R1 and the region R2 are also located on the side close to the light source, but in the two regions R1 and R2, the density of the condenser lenses 260a and 260b is not the same. In FIG. 2C , the distance between the condenser lenses 260 a in the region R1 is larger than the distance between the condenser lenses 260 b in the region R2 .

Referring to Fig. 3A and Fig. 3B, the light guide plate 300 has a truncated conical condensing lens 360, and the condensing lens 360 located between the first prism 340a and the second prism 340b and the condensing lens 360 located between the second prism 340b and the third prism 340c The condenser lenses 360 are arranged in a staggered manner to distribute the light more evenly. Wherein the first prism 340 a , the second prism 340 b and the third prism 340 c are triangular prisms 340 that are randomly arranged continuously among the plurality of prisms 340 of the light guide plate 300 .

Referring to Fig. 4, in the light guide plate 400 of another embodiment, the condenser lenses 460 can be scattered between every adjacent two prisms 440 in a dot shape, and the condenser lenses 460 near the light incident side are distributed more sparsely, and the more The distribution of the condenser lenses 460 away from the light incident side is denser. As shown in FIG. 2A , FIG. 3A and FIG. 4 , the condenser lenses 260 , 360 , and 460 can be cylindrical, conical, spherical, or other shapes of light-condensing structures. That is, the condenser lenses 260, 360, 460 may be spherical or aspherical condenser lenses.

FIG. 5 shows an inverted backlight module 500 for convenience in illustrating the features of the present invention. The backlight module 500 includes the above-mentioned light guide plate 300 , light source 520 , brightness enhancement film 540 and diffusion film 560 . The light guide plate 300 includes a light-transmitting substrate 320 , a prism 340 and a condenser lens 360 . The transparent substrate 320 has a bottom surface 322 , a light exit surface 324 and a light incident surface 326 . The light emitting surface 324 is opposite to the bottom surface 322 , and the light incident surface 326 connects the bottom surface 322 and the light emitting surface 324 . The brightness enhancement film 540 and the diffusion film 560 are disposed on the light emitting direction of the light emitting surface 324 . The light source 520 is disposed on one side of the transparent substrate 320 and faces the light incident surface 326 . A plurality of prisms 340 protrude from the bottom surface 322 and are arranged side by side on the bottom surface 322 . A plurality of condenser lenses 360 are disposed between every two adjacent prisms 340 , and are distributed from sparse to dense along the ridgeline direction of the prisms 340 from the light incident surface. The light emitted by the light source 520 enters the light guide plate 300 from the light incident surface 326 , is converged by the prism 340 and the condenser lens 360 , and exits through the light exit surface 324 .

In all the preferred embodiments of the above edge-lit backlight modules, the direction of the ridge line of the prism is parallel to the light incident direction of the light source. The light source can consist of a point light source or a line light source, such as a light emitting diode or a cold cathode ray tube. Using the condenser lens between two adjacent prisms to adjust the optical picture and optical performance can improve the utilization rate of the light source.

The above is only a preferred embodiment of the utility model, and should not limit the scope of implementation of the utility model, that is, all simple equivalent changes and modifications made according to the claims of the utility model and the description of the utility model, All still belong to the scope that the utility model patent covers. In addition, any embodiment or claim of the utility model does not need to achieve all the purposes or advantages or features disclosed in the utility model. In addition, the abstract part and the title are only used to assist the search of patent documents, and are not used to limit the scope of rights of the present utility model.

Claims (16)

1, a kind of light guide plate is characterized in that, comprising:

Light-transparent substrate has face;

A plurality of prisms are arranged on described of described light-transparent substrate side by side; And

A plurality of collector lenses are disposed between every adjacent two described prisms, and along the crest line direction of described prism by dredging to close distribution.

2, light guide plate as claimed in claim 1 is characterized in that, wherein said collector lens and described light-transparent substrate are one-body molded.

3, light guide plate as claimed in claim 1 is characterized in that, described the part between every adjacent two described prisms of wherein said light-transparent substrate is the par, and described collector lens is distributed on the described par.

4, light guide plate as claimed in claim 1 is characterized in that, wherein said prism has first height, and described collector lens has second height, and described second height is less than described first height.

5, light guide plate as claimed in claim 1, it is characterized in that, wherein said prism comprises first prism, second prism and prism, and described collector lens the part between described second and third prism is staggered in part between described first and second prism and described collector lens.

6, light guide plate as claimed in claim 1 is characterized in that, wherein said collector lens is cylindric, spherical or round table-like.

7, light guide plate as claimed in claim 1 is characterized in that, wherein said collector lens is sphere or aspheric surface shape.

8, a kind of side light type back light module is characterized in that, comprising:

Light-transparent substrate has bottom surface, light-emitting face and light entrance face, and wherein said light-emitting face is relative with described bottom surface, and described light entrance face connects described bottom surface and described light-emitting face;

Light source is located at a side of described light-transparent substrate, and towards described light entrance face;

A plurality of prisms protrude from described bottom surface, and are arranged in side by side on the described bottom surface; And

A plurality of collector lenses are disposed between every adjacent two described prisms, and along the crest line direction of described prism, from described light entrance face by dredging to close distribution,

The light that wherein said light source sent is incident in the described light-transparent substrate by described light entrance face, after assembling by described prism and described collector lens, penetrates via described light-emitting face.

9, backlight module as claimed in claim 8 is characterized in that, the crest line direction of wherein said prism is parallel to the light incident direction of described light source.

10, backlight module as claimed in claim 8 is characterized in that, the part of the described bottom surface of wherein said light-transparent substrate between every adjacent two described prisms is the par, and described collector lens is distributed on the described par.

11, backlight module as claimed in claim 8 is characterized in that, wherein said prism has first height, and described collector lens has second height, and described second height is less than described first height.

12, backlight module as claimed in claim 8, it is characterized in that, wherein said prism comprises first prism, second prism and prism, and described collector lens the part between described second and third prism is staggered in part between described first and second prism and described collector lens.

13, backlight module as claimed in claim 8 is characterized in that, wherein said collector lens is cylindric, spherical or round table-like.

14, backlight module as claimed in claim 8 is characterized in that, wherein said collector lens is sphere or aspheric surface shape.

15, backlight module as claimed in claim 8 is characterized in that, wherein said collector lens and described light-transparent substrate are one-body molded.

16, backlight module as claimed in claim 8 is characterized in that, wherein said light source has light emitting diode.

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