CN101315438A - Diffusion polarizing plate and backlight module using same - Google Patents

Abstract

The present invention discloses a diffusion polarizer, which includes a substrate and a microstructure layer, wherein the microstructure layer is disposed on the substrate, wherein the microstructure layer includes a solid liquid crystal material, and the solid liquid crystal material has birefringence. The diffusion polarizer has the functions of homogenizing and polarizing incident light. In addition, the present invention also discloses a backlight module using the diffusion polarizer.

Description

Diffusing polarizer and backlight module using same

technical field

The present invention relates to an optical film (optical film) and a light source module using the same, and in particular to a diffusing polarizer (diffusing polarizer) and a backlight module using the same.

Background technique

With the increasingly developed electronic industry, flat panel displays have eliminated cathode ray tube displays and become the current mainstream. Among the flat panel displays, the liquid crystal display technology is the most mature and popular. However, since the liquid crystal display panel of the liquid crystal display itself cannot emit light, a backlight module must be provided under the liquid crystal display panel to provide a light source to achieve the display function.

FIG. 1 is a cross-sectional view of a known backlight module. Please refer to FIG. 1 , the backlight module 100 includes a plurality of light sources 110 , a plurality of optical films 120 and a light box 130 . The light source 110 is disposed in the light box 130 , and the light box 130 fixes the light source 110 and the optical film 120 . The light emitted by the light source 110 passes through the optical film 120 to form a uniform and concentrated surface light source.

It is known that an optical film set usually includes a diffusion sheet and a brightness enhancement sheet, the diffusion sheet can make the incident light uniform, and the brightness enhancement sheet can concentrate the light to improve the use efficiency of the light source.

In addition, it is known that the enhancement sheet can also have birefringence, so that the incident light of a specific polarization direction can pass through, and the incident light of other polarization directions can be reflected and reused. This can increase the ratio of light entering the liquid crystal display panel. However, it is known that the way to achieve birefringence in the brightness enhancement sheet is to alternately stack multiple layers of materials with different refractive indices. In this way, not only the weight and thickness of the brightness enhancement sheet cannot be reduced, In addition, when the light passes through the interface between the various layers of materials, loss will also occur, which reduces the use efficiency of the light source and limits the production yield.

Contents of the invention

The invention provides a diffuse polarizer, which has the functions of polarizing and homogenizing incident light.

The present invention further provides a backlight module, which can reduce the number of components by using the above-mentioned diffuse polarizer.

The invention proposes a diffuse polarizer, which includes a substrate and a microstructure layer, and the microstructure layer is disposed on the substrate, wherein the microstructure layer includes a solid liquid crystal material, and the solid liquid crystal material has birefringence.

In an embodiment of the present invention, the above-mentioned diffusing polarizer further includes a plurality of diffusing particles doped in the substrate.

In an embodiment of the present invention, the microstructure layer includes a plurality of protrusions.

In an embodiment of the present invention, each of the protrusions is a strip structure, and the strip structures are arranged in a grid.

In an embodiment of the present invention, the vertical cross-sections of the above-mentioned protrusions are triangular.

In an embodiment of the present invention, the vertical cross-section of each of the protrusions is trapezoidal.

In an embodiment of the present invention, the vertical cross-section of each of the protrusions is semi-elliptical.

In an embodiment of the present invention, each of the above-mentioned protrusions is a ring structure, and the ring structures are arranged in concentric circles.

In an embodiment of the present invention, the above-mentioned protrusions are cone-shaped structures, and the cone-shaped structures are arranged regularly.

In an embodiment of the present invention, the above-mentioned protrusions are cone-shaped structures, and the cone-shaped structures are arranged irregularly.

The present invention further provides a backlight module, which includes a surface light source device and a diffusion polarizer. The surface light source device has a light-emitting surface. The diffuse polarizer is arranged above the light-emitting surface of the surface light source device, wherein the diffuse polarizer includes a base material and a microstructure layer. The microstructure layer is configured on the substrate, wherein the microstructure layer includes solid liquid crystal material, and the solid liquid crystal material has birefringence.

In an embodiment of the present invention, the base material of the above-mentioned diffusing polarizer further includes a plurality of diffusing particles.

In an embodiment of the present invention, the microstructure layer includes a plurality of protrusions.

In an embodiment of the present invention, each of the protrusions is a strip structure, and the strip structures are arranged in a grid.

In an embodiment of the present invention, the vertical cross-sections of the above-mentioned protrusions are triangular.

In an embodiment of the present invention, the vertical cross-section of each of the protrusions is trapezoidal.

In an embodiment of the present invention, the vertical cross-section of each of the protrusions is semi-elliptical.

In an embodiment of the present invention, each of the above-mentioned protrusions is a ring structure, and the ring structures are arranged in concentric circles.

In an embodiment of the present invention, the above-mentioned protrusions are cone-shaped structures, and the cone-shaped structures are arranged regularly.

In an embodiment of the present invention, the above-mentioned protrusions are cone-shaped structures, and the cone-shaped structures are arranged irregularly.

In an embodiment of the present invention, the surface light source includes a direct light source or a side light source.

In an embodiment of the present invention, the surface light source has at least one light emitting element.

In an embodiment of the present invention, the above-mentioned light-emitting element includes an organic electroluminescence element, a CCFL flat lamp, a CCFL tube, or a light-emitting diode.

Because the diffusion polarizer of the present invention uses a solid liquid crystal material with birefringence, the function of birefringence can be achieved without a multilayer structure, and when the diffusion polarizer is applied to a backlight module, the optical density of the backlight module can be reduced. Diaphragm number, thickness and weight.

In order to make the above-mentioned features and advantages of the present invention more comprehensible, preferred embodiments will be described in detail below together with the accompanying drawings.

Description of drawings

FIG. 1 is a cross-sectional view of a known backlight module.

FIG. 2 is a cross-sectional view of a diffuse polarizer in an embodiment of the present invention.

FIG. 3 is a cross-sectional view of a diffuse polarizer in another embodiment of the present invention.

FIG. 4 is a schematic diagram of the arrangement of the protrusions in FIG. 2 .

5 and 6 are cross-sectional views of other embodiments of the protrusion in FIG. 2 .

7 to 9 are schematic diagrams of other configurations of the protrusions in FIG. 2 .

FIG. 10 is a cross-sectional view of a backlight module according to an embodiment of the present invention.

FIG. 11 is a cross-sectional view of a backlight module according to another embodiment of the present invention.

Explanation of reference signs

100: Backlight module 110: Light source

120: Optical film 130: Light box

200: Diffuse polarizer 210: Substrate

212: Diffusion Particles 220: Microstructure Layer

222: Solid liquid crystal material 222a: Drop-like polymer dispersed liquid crystal

224: Protrusion 300, 300’: Backlight module

310, 310': surface light source 310a: light emitting surface

312: Light emitting element 314: Light box

316: Light guide plate 318: Lampshade

318a: opening

Detailed ways

FIG. 2 is a cross-sectional view of a diffuse polarizer in an embodiment of the present invention. Referring to FIG. 2 , the diffuse polarizer 200 includes a substrate 210 and a microstructure layer 220 , wherein the microstructure layer 220 is disposed on the substrate 210 . The microstructure layer 220 includes a solid liquid crystal material 222, and the solid liquid crystal material 222 has birefringence. The material of the substrate 210 is, for example, polyethylene terephthalate (polyethylene terephthalate, PET), polymethyl methacrylate (polymethyl methacrylate, PMMA), polycarbonate (polycarbonate, PC), polystyrene (polystyrene, PS), etc., the microstructure layer 220 is, for example, an ultraviolet curable adhesive. The solid liquid crystal material 222 includes, for example, a plurality of drop-like polymer dispersed liquid crystal drops 222a formed by combining polymer glue and liquid crystal molecules. The microstructure layer 220 can achieve the effect of aligning each drop-shaped polymer dispersed liquid crystal 222a through structural design, so that the microstructure layer 220 has birefringence, and the microstructure layer 220 can be cured by ultraviolet light to fix the drop-shaped polymer The alignment of the liquid crystal 222a is dispersed. In addition, in this embodiment, the alignment of each drop-shaped polymer dispersed liquid crystal 222a can also be improved by applying an external electric field or applying an external alignment force.

Because the solid-state liquid crystal material 222 of the diffusion polarizer 200 has birefringence, it can allow light in a specific polarization direction to pass through and reflect light in other polarization directions, so the diffusion polarizer 200 has the function of polarizing light, and the diffusion polarizer 200 has the function of polarizing light. 200 is scattered reflection when reflecting light, so the diffusion polarizer 200 has the function of uniformizing light. In this way, only one diffusing polarizer 200 is required to simultaneously have the effects of the reflective polarizer and the diffuser.

FIG. 3 is a cross-sectional view of a diffuse polarizer in another embodiment of the present invention. In this embodiment, a plurality of diffusing particles 212 may be mixed in the substrate 210 of the diffusing polarizer 200a, so as to further enhance the effect of the diffusing polarizer 200a on light uniformity. In addition, the microstructure layer 220 may further include a plurality of protrusions 224 , and the protrusions 224 can concentrate the light passing through the diffuser polarizer 200 to improve the use efficiency of the light. FIG. 4 is a schematic diagram of the arrangement of the protrusions in FIG. 2 . Please refer to Fig. 2 and Fig. 4, as can be seen from Fig. 4, protrusion 224 is a strip structure, and is arranged in a grid shape, and as can be seen in Fig. 2, the vertical section of protrusion 224 is triangular, but the present invention does not This is the limit. 5 and 6 are cross-sectional views of other embodiments of the protrusion in FIG. 2 . Please refer to FIG. 5 and FIG. 6 , it can be seen from FIG. 5 that the vertical section of the microstructure layer 220 is semi-elliptical, while in FIG. 6 , the vertical section of the microstructure layer 220 is trapezoidal.

In addition, the structure of the protrusions 224 is not limited to the above strip structure. FIGS. 7 to 9 are schematic diagrams of other configurations of the protrusions in FIG. 2 . Please refer to FIG. 7 first. It can be seen from FIG. 7 that the protrusions 224 are annular structures, and the annular structures are arranged in concentric circles. Please refer to FIG. 8 and FIG. 9 , in FIG. 8 , the protrusions 224 are conical structures arranged regularly, and in FIG. 9 , the protrusions 224 are also conical structures arranged irregularly. It should be noted that although the protrusion 224 in FIG. 8 and FIG. 9 is illustrated as a pyramid shape, those skilled in the art can also change the protrusion 224 to other shapes, such as a conical shape, as required.

It should be noted that the diffusion polarizers in the above embodiments can all be shown in FIG. 3 , with diffusion particles added to the substrate to enhance the diffusion effect.

The backlight module using the above-mentioned diffuse polarizer will be described below with reference to the drawings. FIG. 10 is a cross-sectional view of a backlight module according to an embodiment of the present invention. Referring to FIG. 10 , the backlight module 300 includes a surface light source 310 and the aforementioned diffuse polarizer 200 , wherein the surface light source 310 has a light emitting surface 310 a, and the diffuse polarizer 200 is disposed on the light emitting surface 310 a.

The surface light source 310 is, for example, a direct light source, which may have a plurality of light emitting elements 312 and a light box 314 , and the light emitting elements 312 are located in the light box 314 . In addition, the surface light source 310 may also be a side-illuminated light source. FIG. 11 is a cross-sectional view of a backlight module according to another embodiment of the present invention. Referring to FIG. 11 , the surface light source 310' of the backlight module 300' is a side-illuminated light source, which has a light emitting element 312, a light guide plate 316 and a lampshade 318. The light emitting element 312 is disposed in the lampshade 318 , and the light guide plate 316 is disposed in the opening 318 a of the lampshade 318 . The light-emitting element 312 is, for example, an organic electroluminescence element, a CCFL flat lamp, a CCFL tube, or a light-emitting diode.

Because the solid-state liquid crystal material of the diffuse polarizer has birefringence, it can pass light in a specific polarization direction and reflect light in other polarization directions, so the diffuse polarizer has the function of polarizing light, and the diffuse polarizer is reflecting light. When it is scattered reflection, the diffusion polarizer has the function of making the light uniform. In addition, the microstructure layer may have a plurality of protrusions, so that the diffusion polarizer has the function of concentrating incident light. In this way, when the diffused polarizer is applied to the backlight module, only one diffused polarizer is required to have the effects of the polarizer, the diffuser, and the brightness enhancement film at the same time, which can not only improve the use efficiency of the surface light source, but also reduce the thickness of the backlight module and The weight can reduce the assembly steps when making the backlight module, thereby saving the cost and increasing the yield.

Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make some changes and modifications without departing from the spirit and scope of the present invention. Therefore The protection scope of the present invention shall prevail as defined by the appended claims.

Claims (23)

1. diffusion polarizing piece comprises:

Base material; And

Microstructured layers is disposed at this base material, and wherein this microstructured layers comprises solid-state liquid crystal material, and this solid-state liquid crystal material has birefringence.

2. diffusion polarizing piece as claimed in claim 1 also comprises a plurality of diffusion particles in its base material.

3. diffusion polarizing piece as claimed in claim 1, wherein this microstructured layers comprises a plurality of projections.

4. diffusion polarizing piece as claimed in claim 3, wherein this projection is a list structure, and this list structure is the palisade arrangement.

5. diffusion polarizing piece as claimed in claim 4, wherein the vertical cross-section of this projection is a triangle.

6. diffusion polarizing piece as claimed in claim 4, wherein the vertical cross-section of this projection is trapezoidal.

7. diffusion polarizing piece as claimed in claim 4, wherein the vertical cross-section of this projection is a half elliptic.

8. diffusion polarizing piece as claimed in claim 3, wherein this projection is a ring texture, and this ring texture is the concentric circles arrangement.

9. diffusion polarizing piece as claimed in claim 3, wherein this projection is a cone structure, and this cone structure is regularly arranged.

10. diffusion polarizing piece as claimed in claim 3, wherein this projection is a cone structure, and this cone structure is irregular alignment.

11. a backlight module comprises:

Area source has exiting surface;

Diffusion polarizing piece is disposed at above this exiting surface of this planar light source device, and this diffusion polarizing piece comprises:

Base material; And

Microstructured layers is disposed at this base material, and wherein this microstructured layers comprises solid-state liquid crystal material, and this solid-state liquid crystal material has birefringence.

12. backlight module as claimed in claim 11, wherein the base material of this diffusion polarizing piece also comprises a plurality of diffusion particles.

13. backlight module as claimed in claim 11, wherein this microstructured layers comprises a plurality of projections.

14. backlight module as claimed in claim 13, wherein this projection is a list structure, and this list structure is the palisade arrangement.

15. backlight module as claimed in claim 14, wherein the vertical cross-section of this projection is a triangle.

16. backlight module as claimed in claim 14, wherein the vertical cross-section of this projection is trapezoidal.

17. backlight module as claimed in claim 14, wherein the vertical cross-section of this projection is a half elliptic.

18. backlight module as claimed in claim 13, wherein this projection is a ring texture, and this ring texture is the concentric circles arrangement.

19. backlight module as claimed in claim 13, wherein this projection is a cone structure, and this cone structure is regularly arranged.

20. backlight module as claimed in claim 13, wherein this projection is a cone structure, and this cone structure is irregular alignment.

21. backlight module as claimed in claim 11, wherein this area source comprises directly-down light source or side incident type light source.

22. backlight module as claimed in claim 11, wherein this area source has at least one light-emitting component.

23. backlight module as claimed in claim 22, wherein this light-emitting component comprises organic electroluminescent device, cold-cathode fluorescent plant lamp, cathode fluorescent tube, or light emitting diode.

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