TW201407240A - Back light module and display device and light source module using same - Google Patents

Abstract

The present invention discloses a back light module, a display device, and a light source module using the same. The back light module includes at least two light sources, a light guide plate, and a diffuser. The diffuser includes a plurality of diffusing particles. The diffusing particles adjacent to the at least two light sources are smaller than the diffusing particles far from the at least two light sources. A density of the diffusing particles adjacent to the at least two light sources is greater than a density of the diffusing particles far from the at least two light sources. Light from the at least two light sources is orderly diffused by the diffusing particles adjacent to the at least two light sources and the diffusing particles far from the at least two light sources, and then output from the light guide plate.

Description

Backlight module, liquid crystal display device and light source module

The invention relates to a backlight module, a liquid crystal display device and a light source module.

A conventional backlight module generally includes a light guiding element and a light source disposed on one side of the light guiding element. The light source mostly uses a light-emitting diode for the sake of energy saving and environmental protection. However, since the light emitted by the light-emitting diode has a strong directivity, a plurality of distinct "bright spots" (hot spots) are easily formed on the light-incident side of the light-guiding element when the distance between two adjacent light-emitting diodes is large. ). Therefore, when the frame structure is provided, it is necessary to reserve a frame for shielding the bright spot area and the light source area at a position close to the light incident side of the light guiding element. The wider backlight frame occupies a larger area of the backlight module, which cannot meet the consumer's demand for the backlight module and the narrow border of the liquid crystal display module.

In view of this, it is necessary to provide a backlight module having a narrow frame area.

In view of this, it is also necessary to provide a liquid crystal display device using the above backlight module.

It is more necessary to provide a light source module with better diffusion effect.

A backlight module includes at least two light sources and a light guiding component, the light guiding component receives light emitted by the at least two point light sources, and the backlight module further includes a light diffusing component, the light diffusing component includes a plurality of diffusing particles, The volume of the diffusion particles adjacent to the at least two-point source is smaller than the volume of the diffusion particles away from the at least two-point source, and the distribution density of the diffusion particles near the at least two-point source is greater than the distribution density of the diffusion particles away from the at least two-point source. The light generated by the at least two-point light source is diffused by the diffusion particles adjacent to the at least two-point light source, and then diffused by the diffusion particles away from the at least two-point light source, and then emitted by the light guiding element.

A liquid crystal display device includes a liquid crystal panel and a backlight module adjacent to the liquid crystal panel and providing a light source for the liquid crystal panel. The backlight module includes at least two light sources and a light guiding component, the light guiding component receives light emitted by the at least two point light sources, and the backlight module further includes a light diffusing component, the light diffusing component includes a plurality of diffusing particles, The volume of the diffusion particles of the at least two-point source is smaller than the volume of the diffusion particles away from the at least two-point source, and the distribution density of the diffusion particles near the at least two-point source is greater than the distribution density of the diffusion particles away from the at least two-point source, the at least The light generated by the two-point light source is diffused by the diffusion particles close to the at least two-point light source, and then diffused by the diffusion particles away from the at least two-point light source, and then emitted by the light guiding element.

A light source module comprising at least two light sources and a light diffusing element, the light diffusing element comprising a first light diffusing layer and a second light diffusing layer, wherein the first light diffusing layer and the second light diffusing layer are provided with diffusing particles, The first light diffusion layer is closer to the at least two point light sources than the second light diffusion layer, and the volume of the diffusion particles in the first light diffusion layer is smaller than the volume of the diffusion particles in the second light diffusion layer, the first The distribution density of the diffusion particles in the light diffusion layer is greater than the distribution density of the diffusion particles in the second light diffusion layer, and the light generated by the at least two point sources is diffused by the diffusion particles close to the at least two point sources, and then away from the at least The diffusion of the diffusion particles of the two-point light source is emitted by the light guiding element.

Compared with the prior art, the light diffusing element of the backlight module has diffusing particles, and the light is diffused by the diffusing particles to expand the angle of propagation, thereby achieving the effect of diffusion, shortening the mixing of the light emitted by the adjacent two-point source. The light mixing distance can significantly narrow the frame of the backlight module and the liquid crystal display device to meet the needs of consumers. In addition, the light source module has a light diffusing element, and the light is relatively uniform.

Please refer to Figure 1 and Figure 2. The liquid crystal display device 2 includes a liquid crystal panel 22 and a backlight module 23. The backlight module 23 is adjacent to the liquid crystal panel 22 and provides backlighting for the liquid crystal panel 22 .

The backlight module 23 includes a plastic frame 25, an optical film group 24, a light guiding element 26, a light source 27, a reflective structure 28, and a light diffusing element 29.

The light guiding element 26 cooperates with the light diffusing element 29 for converting the light emitted by the light source 27 into planar light. The light guiding element 26 includes a top surface 260, a bottom surface 263 disposed opposite the top surface 260, and a light incident surface 265 on the side of the light guiding element 26 and connected to the top surface 260 and the bottom surface 263, respectively. The optical film set 24 is disposed on the side of the top surface 260. The reflective structure 28 is disposed on the bottom surface 263 of the light guiding element 26. The light diffusing element 29 is disposed on the light incident surface 265. On the other side of the light diffusing element 29 opposite to the light guiding element 26.

The light source 27 includes a circuit board 271 and at least two point light sources 272 disposed on the circuit board 271. Each of the point light sources 272 has a light emitting surface 273 through which light generated by the point light source 272 is emitted. The circuit board 271 supplies power to the point source 272.

The reflective structure 28 is for reflecting the light leakage of the light guiding element 26, the light diffusing element 29, and the light source 27 to improve the utilization of light. The reflective structure 28 is a reflective sheet in the present embodiment.

The light diffusing element 29 is formed of a light transmissive material, and includes a first light diffusing layer 291, a second light diffusing layer 293, and a third light diffusing layer 295 which are sequentially disposed from the light source 27 to the light incident surface 265. A surface of the first light diffusion layer 291 remote from the second light diffusion layer 293 serves as a light incident surface 296 of the light diffusion element 29, and a surface of the third light diffusion layer 295 remote from the second light diffusion layer 293 serves as the surface In the light exit surface 299 of the light diffusing element 29, that is, in the present embodiment, the light incident surface 296 and the light exit surface 299 of the light diffusing element 29 are disposed on opposite sides of the light diffusing element 29. The light incident surface 296 is for receiving light emitted by the light source 27, and the light exit surface 299 is for transmitting light received by the light diffusing element 29 to the light guiding element 26. The refractive index n1 of the first light diffusion layer 291, the refractive index n2 of the second light diffusion layer 293, and the refractive index n3 of the third light diffusion layer 295 conform to the following relationship: n1>n2>n3. At the same time, the refractive index n3 of the third light diffusion layer 295 has a refractive index greater than that of the light guiding element 26. Specifically, the material of each layer of the light diffusing element 29 may be selected from polystyrene (PS), polycarbonate (PC), polymethyl methacrylate (PMMA) or epoxy resin Epoxy resins. High light transmissive material. The light diffusing element 29 may have a separate structure from the light guiding element 26 or may be combined into a single structure by a technique such as two-material molding. The first light diffusion layer 291, the second light diffusion layer 293, and the third light diffusion layer 295 may have a separate structure, or may be combined into a unitary structure by a technique such as two-material molding. It can be understood that the number of layers included in the light diffusing element 29 can be changed according to actual needs, such as a two-layer film structure, or a four-layer film structure or a plurality of film structures.

In addition, diffusion particles 298 are disposed in the first light diffusion layer 291, the second light diffusion layer 293, and the third light diffusion layer 295 to change the propagation path of the light. The diffusing particles 298 may be selected from light transmissive materials having a refractive index less than the refractive index of the substrate medium in which they are located. For example, the refractive index of PS is smaller than the refractive index of PC, and the refractive index of PC is approximately equal to the refractive index of PMMA. If the substrate, such as the first light diffusion layer 291, is selected from PMMA or PC, the diffusion particles 298 may be PS. Further, the volume and distribution density of the diffusion particles 298 disposed on the different diffusion layers are also different. The particle size/volume of the diffusion particles 298 in the first light diffusion layer 291 near the light source 27 is the smallest and the density is the largest; the particle size/volume of the diffusion particles 298 in the third light diffusion layer 295 far from the light source 27 is the largest and the density is the smallest. That is, from the direction of the light source 27 to the light incident surface 265 of the light guiding element 26, the particle diameter/volume of the diffusion particles 298 gradually increases, and the distribution density gradually decreases. This can increase the probability of light hitting the diffusing particles 298 and increase the effect of light divergence.

In addition, in the present embodiment, the interface between the first light diffusion layer 291 and the second light diffusion layer 293, and the interface between the second light diffusion layer 293 and the third light diffusion layer 295, And a microstructure 290 may be disposed on the interface between the third light diffusing layer 295 and the light incident surface 265 of the light guiding element 26 for further diffusing and transmitting incident light. Specifically, the shape of the microstructure 290 may adopt a V-shaped groove, a cylindrical groove, a conical groove, a hemispherical groove, or the like. It is understood that the groove is defined according to the disposed internal concave, the above shapes. It may also be defined as a structure in which a V-shaped projection, a cylindrical projection, a conical projection, a hemispherical projection, or the like, which is convex outwardly provided, or a mixture of one or more of the above-described respective structures. For the stereo setting method, refer to the content shown in FIG. In Fig. 3, the V-shaped grooves arranged in parallel are taken as an example to show the arrangement and distribution of the microstructures arranged on the interface.

The plastic frame 25 is a hollow frame, and the plastic frame 25 includes a first side plate 251, a second side plate 252, a third side plate 253, and a fourth side plate 254. The first side plate 251, the second side plate 252, the third side plate 253, and the fourth side plate 254 are connected end to end to form an annular structure. The inner side of the first side panel 251, the second side panel 252, the third side panel 253, and the fourth side panel 254 extend toward the center of the plastic frame 25 to extend a receiving plate 255 to divide the receiving space enclosed by the plastic frame 25 into two The first receiving space is for carrying the liquid crystal panel 22, and the second receiving space is for receiving other components of the backlight module 23. The support plate 255 extending from the fourth side plate 254 has a wide width for shielding the light diffusing element 29 and the light source 27. The width of the support plate 255 extending from the fourth side plate 254 refers to the distance from the fourth side plate 254 to the edge of the support plate 255 located inside the plastic frame 25.

The bottom surface 263 of the light guiding element 26 is disposed on the reflective structure 28, and the light diffusing element 29 is integrally formed on the light guiding element 26, wherein the light emitting surface 299 is attached to the light guiding element 26 The entrance surface 265. The light source 27 is disposed on the light incident surface 296 side of the light diffusing element 29, and the light emitting surface 273 faces the light incident surface 296. The optical film set 24 is disposed on the top surface 260 of the light guiding element 26. The optical film group 24, the light guiding element 26, the light diffusing element 29, and the light source 27 are disposed inside the plastic frame 25 for accommodation. The support plate 255 is disposed on the top surface 260 of the light guiding element 26 . The liquid crystal panel 22 is disposed on the support plate 255.

The light emitted from the light source 27 enters the light diffusing element 29 via the light incident surface 296, and passes through the first light diffusing layer 291 and the diffusing particles 298, the second light diffusing layer 293, the diffusing particles 298, and the third light diffusing layer 295. The refracting particles 298 are incident on the light incident surface 265 by the light exit surface 299, enter the light guiding element 26, and are emitted by the top surface 260 by the reflection structure 28 of the bottom surface 263 of the light guiding element 26.

Due to the multiple diffusion of the diffusion particles 298, the light emitted by the adjacent two-point source 272 can be overlapped and mixed faster after exiting from the point source 272, so that the distinct "bright spot" region becomes smaller. At the same time, since the directivity of the light near the light source 27 is strong, the diffusion particles 298 having a small particle size/volume and a large distribution density are used to increase the number of times the light hits the diffusion particles 298 and is reflected, thereby increasing the effect of light divergence. The directivity of the light after the multi-layer propagation of the light has been weakened, so that the diffusion particles 298 having a large particle size/volume and a small distribution density can be used to make the light source diffuse more uniformly. Further, the refractive index n1 of the first light diffusion layer 291, the refractive index n2 of the second light diffusion layer 293, and the refractive index n3 of the third light diffusion layer 295 conform to the following relationship: n1>n2>n3, and the third light The refractive index n3 of the diffusion layer 295 has a refractive index greater than that of the light guiding element 26. Therefore, the light is refracted multiple times at the interface position of each layer film to expand the angle of propagation, thereby achieving the effect of diffusion, and shortening the light mixing distance between adjacent two-point light sources 272. The width of the support plate 255 of the fourth side plate 254, which is an unsuitable area for shielding the light-emitting effect, can be significantly narrowed, so that the backlight module 23 and the frame area of the liquid crystal display device 2 to which the backlight module 23 is applied are narrowed to satisfy the consumer. demand.

In addition, in other embodiments of the present invention, the first light diffusion layer 291, the second light diffusion layer 293, and the third light diffusion layer 295 may be made of the same material, and it is not difficult to understand that the first light diffusion layer 291 is There is no occurrence of refraction at the interface between the second light diffusion layer 293 and the third light diffusion layer 295. Further, if the refractive index of the light diffusing element 29 is larger than that of the light guiding element 26, refraction occurs at the interface between the two, and again, when the refractive index of the light diffusing element 29 is equal to the refractive index of the light guiding element 26. The diffusing particles 298 of the light diffusing element 29 can function to break up the light. Further, the diffusion particles may be disposed directly in the light guiding element 26, and the volume and distribution law thereof are also smaller in the region close to the light source 27, and the density is larger, and the volume in the region far from the light source 27 is larger. The lower the density.

In another embodiment of the present invention (the above reference numeral), the backlight module 23 includes a light source module (not shown), and the light source module includes at least two point light sources 272 and a light diffusing element 29. The light diffusing element 29 includes a first light diffusing layer 291 and a second light diffusing layer 293. Diffusion particles 298 are provided in the first light diffusion layer 291 and the second light diffusion layer 293. The first light diffusion layer 291 is closer to the at least two-point light source 272 than the second light diffusion layer 293. The volume of the diffusion particles 298 in the first light diffusion layer 291 is smaller than the volume of the diffusion particles 298 in the second light diffusion layer 293. The distribution density of the diffusion particles 298 in the first light diffusion layer 291 is larger than the distribution density of the diffusion particles 298 in the second light diffusion layer 293. The light generated by the at least two-point light source 272 is diffused by the diffusion particles 298 of the first light diffusion layer 291, and then diffused by the diffusion particles 298 of the second light diffusion layer 293. Alternatively, the refractive index of the first light diffusion layer 291 is greater than the refractive index of the second light diffusion layer 293. The diffusion particle 298 is a light transmissive material. The refractive index of the diffusion particle 298 in the first light diffusion layer 291 is smaller than the refractive index of the medium of the first light diffusion layer 291, and the diffusion particle 298 in the second light diffusion layer 293. The refractive index is smaller than the refractive index of the second light diffusion layer 293 medium in which it is located.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

2. . . Liquid crystal display device

twenty two. . . LCD panel

twenty three. . . Backlight module

25. . . Plastic frame

twenty four. . . Optical film set

26. . . Light guiding element

27. . . light source

28. . . Reflective structure

29. . . Light diffusing element

290. . . microstructure

291. . . First light diffusion layer

293. . . Second light diffusion layer

295. . . Third light diffusion layer

296. . . Light incident surface

298. . . Diffused particle

299. . . Light exit surface

251. . . First side panel

252. . . Second side panel

253. . . Third side panel

254. . . Fourth side panel

255. . . Support plate

260. . . Top surface

263. . . Bottom

265. . . Glossy surface

271. . . Circuit board

272. . . point Light

273. . . Luminous surface

1 is a perspective exploded view of an embodiment of a liquid crystal display device of the present invention.

2 is a schematic plan view showing a light guiding element, a light diffusing element, and a light source of the liquid crystal display device of FIG. 1.

3 is a partial perspective view of the first light diffusion layer and the second light diffusion layer of the light diffusing element of FIG.

26. . . Light guiding element

29. . . Light diffusing element

291. . . First light diffusion layer

293. . . Second light diffusion layer

295. . . Third light diffusion layer

296. . . Light incident surface

298. . . Diffused particle

299. . . Light exit surface

260. . . Top surface

265. . . Glossy surface

273. . . Luminous surface

Claims (10)

A backlight module includes at least two light sources and a light guiding component, the light guiding component receives light emitted by the at least two point light sources, wherein the backlight module further comprises a light diffusing component, the light diffusing component comprises a plurality of diffusion a particle, a volume of the diffusion particle adjacent to the at least two point source is smaller than a volume of the diffusion particle away from the at least two point source, and a distribution density of the diffusion particle adjacent to the at least two point source is greater than a distribution of the diffusion particle away from the at least two point source Density, the light generated by the at least two-point light source is diffused by the diffusion particles close to the at least two-point light source, and then diffused by the diffusion particles away from the at least two-point light source, and then emitted by the light guiding element. The backlight module of claim 1, wherein the light diffusing element comprises a first light diffusing layer and a second light diffusing layer, wherein the diffusing particles are disposed in the first light diffusing layer and the second light diffusing layer a surface of the first light diffusion layer remote from the second light diffusion layer serves as a light incident surface of the light diffusion element, and a surface of the second light diffusion layer remote from the first light diffusion layer serves as light of the light diffusion element The emission surface, the volume of the diffusion particles in the first light diffusion layer is smaller than the volume of the diffusion particles in the second light diffusion layer, and the distribution density of the diffusion particles in the first light diffusion layer is greater than the diffusion in the second light diffusion layer The distribution density of the particles, the light generated by the at least two-point light source enters the light diffusing element through the light incident surface, and is diffused by the diffusing particles in the light diffusing layer, and then emitted by the light guiding element. The backlight module of claim 2, wherein the diffusion particles are light transmissive materials, and the refractive index of the diffusion particles in the first light diffusion layer is smaller than the refractive index of the first light diffusion layer medium in which the first light diffusion layer is located. The refractive index of the diffusion particles in the second light diffusion layer is smaller than the refractive index of the second light diffusion layer medium in which it is located. The backlight module of claim 3, wherein a refractive index of the first light diffusion layer is greater than a refractive index of the second light diffusion layer, and a refractive index of the second light diffusion layer is greater than the light guiding element Refractive index. The backlight module of claim 2, wherein a refractive index of the first light diffusion layer is the same as a refractive index of the second light diffusion layer, and a refractive index of the light diffusion element is greater than that of the light guiding element Refractive index. The backlight module of claim 2, wherein the refractive index of the first light diffusion layer, the refractive index of the second light diffusion layer, and the refractive index of the light guiding element are the same. The backlight module of claim 1, wherein the backlight module further comprises a plastic frame for accommodating the at least two point light sources, the light guiding element and the light diffusing element, the plastic frame comprising a first side plate, a second side panel, a third side panel, and a fourth side panel, wherein the first side panel, the second side panel, the third side panel, and the fourth side panel are connected end to end to form an annular structure, the first side panel, the second side panel, and the third side panel The inner side of the fourth side panel extends a support plate to the center of the plastic frame to divide the receiving space enclosed by the plastic frame into two parts, and the supporting plate of the fourth side plate blocks the light diffusing element and the at least two points light source. A liquid crystal display device comprising a liquid crystal panel and a backlight module adjacent to the liquid crystal panel and providing a light source for the liquid crystal panel, wherein the backlight module is according to any one of claims 1 to 7. Backlight module. A light source module, wherein the light source module comprises at least two point light sources and a light diffusing element, the light diffusing element comprises a first light diffusing layer and a second light diffusing layer, the first light diffusing layer and the second light diffusing layer Dispersing particles are disposed inside, the first light diffusion layer is closer to the at least two point light sources than the second light diffusion layer, and the volume of the diffusion particles in the first light diffusion layer is smaller than that of the diffusion particles in the second light diffusion layer a volume, a distribution density of the diffusion particles in the first light diffusion layer is greater than a distribution density of the diffusion particles in the second light diffusion layer, and the light generated by the at least two point sources is diffused by the diffusion particles adjacent to the at least two point sources. Then, it is emitted by diffusion of the diffusion particles away from the at least two-point light source. The light source module of claim 9, wherein the first light diffusion layer has a refractive index greater than a refractive index of the second light diffusion layer, the diffusion particle is a light transmissive material, and the first light diffusion layer diffuses The refractive index of the particles is smaller than the refractive index of the first light diffusion layer medium in which the particles are located, and the refractive index of the diffusion particles in the second light diffusion layer is smaller than the refractive index of the second light diffusion layer medium in which the second light diffusion layer is located.