CN101571647A - Backlight module and liquid crystal display using the same - Google Patents

Abstract

The invention provides a backlight module and a liquid crystal display using the backlight module. The optical film comprises an optical film and a plurality of prisms, wherein one surface of the optical film comprises at least one prism structure, a plurality of triangular prisms are respectively arranged at a plurality of prism arrangement positions on the prism structure, a base angle of each triangular prism is determined by a curve slope of a curve corresponding to the prism arrangement position of the triangular prism, and the base angle is the base angle which is far away from a central line of the section of the prism structure in two base angles in contact with the optical film; in addition, the light source is arranged on one side of the optical film along the central line, wherein the light rays diffused by the light source directly irradiate the optical film.

Description

Backlight module and liquid crystal display using the backlight module

technical field

The invention relates to a backlight module, in particular to a backlight module with an optical film of prism structure and a liquid crystal display using the backlight module.

Background technique

The backlight module is one of the key components of flat-panel display products such as liquid crystal displays, and is used to provide a stable and uniform light source for the display. In general, a backlight module includes a light source, a light guide plate, a diffusion sheet, and several optical films or prism sheets, wherein the light emitted by the light source passes through the light guide plate to scatter the light to The display panel is then passed through a diffusion plate to evenly disperse the light, and finally through an optical film or a prism sheet to increase the concentration of the light and improve the brightness of the backlight module. However, when the light passes through the diffusion plate, the energy of the light will be lost, so the brightness of the backlight module will often be reduced.

Contents of the invention

The object of the present invention is to provide a backlight module with an optical film with a prism structure and a liquid crystal display using the backlight module, so that the backlight module can achieve the purpose of light uniformity without using a diffuser plate.

According to an embodiment of the present invention, it discloses a backlight module. The backlight module includes a light source and at least one optical film. One surface of the optical film includes at least one prism structure, and a plurality of triangular prisms are respectively arranged at a plurality of prism setting positions on the prism structure, and a base angle of each triangular prism is corresponding to the prism setting position of the triangular prism It is determined by the slope of a curve, and the base angle is the base angle that is farther away from a center line of the cross section of the prism structure among the two base angles where the triangular prism contacts the optical film; in addition, the light source is along The central line is set on one side of the optical film.

According to an embodiment of the present invention, it further discloses a liquid crystal display, which includes a light source, at least one optical film and a display panel. One surface of the optical film includes at least one prism structure, and a plurality of triangular prisms are respectively arranged at a plurality of prism setting positions on the prism structure, and a base angle of each triangular prism is corresponding to the prism setting position of the triangular prism Determined by the slope of a curve, and the base angle is the base angle that is farther away from a center line of the cross-section of the prism structure among the two base angles where the triangular prism contacts the optical film; wherein the light source diverges The light from the light source is directly irradiated on the optical film; in addition, the light source is arranged on one side of the optical film along the center line, and the light emitted by the light source is directly irradiated on the optical film.

Therefore, the backlight module of the present invention can use the optical film of the present invention to achieve light uniformity and increase light concentration without using a diffuser plate.

Description of drawings

1 is a side view of a backlight module according to an embodiment of the present invention;

Fig. 2 is the schematic diagram of the prism structure of optical film of the present invention and manufacturing method thereof;

3A-3C are schematic diagrams of determining another base angle of the triangular prism when the prism structure faces the light source;

4A-4B are schematic diagrams of determining another base angle of the triangular prism when the prism structure is facing away from the light source;

Fig. 5 is a schematic diagram of the relative position of the optical film and the line light source when the light source is a line light source;

FIG. 6 is a schematic diagram of the relative positions of the optical film and the point light source when the light source is a point light source.

Description of main component symbols

100 Backlight module 110 light source 120 Optical film 122 Prism structure 210 curve 510 line light source 610 point Light

Detailed ways

Please refer to FIG. 1 , which is a side view of a backlight module 100 according to an embodiment of the present invention. As shown in FIG. 1, the backlight module 100 includes a plurality of light sources 110 and an optical film 120, wherein the optical film 120 includes a plurality of prism structures fabricated on a surface of the optical film 120 and corresponding to the plurality of light sources 110. 122. In addition, each prism structure 122 is made up of a plurality of triangular prisms with different base angles, and the plurality of triangular prisms are symmetrical to the centerline of the prism structure 122, and each light source 110 is along the center line of the prism structure 122 The lines are disposed on one side of the optical film 120 and located on the centerline of the corresponding prism structure 122 .

Please refer to FIG. 2 , which is a schematic diagram of the prism structure 122 of the optical film 120 of the present invention and its related manufacturing method. As shown in Figure 2, first, a curve 210 is determined according to the type of light source 110 and the distance between the optical film 120 and the light source 110, wherein the type of light source 100 refers to the type of light source and the divergence angle of the light source as shown in Figure 1 ψ, and the distance between the optical film 120 and the light source 110 is the distance d shown in FIG. The coordinates of the positions where the plurality of prisms are set. The manufacturing method of the prism structure 122 is after the curve 210 is determined, the curve 210 is differentiated once to obtain a plurality of curve slopes corresponding to the installation positions of the triangular prisms on the section of the prism structure 122, and then according to the plurality of curve slopes, the curve 210 is obtained. Corresponding to the tangent line of the arranging positions of the plurality of triangular prisms; finally, a plurality of triangular prisms are respectively arranged in the arranging positions of the plurality of triangular prisms on a surface of the optical film 120, wherein a base angle of each triangular prism is equal to that on the curve 210 Corresponding to the tangent angle of the prism installation position of the triangular prism, and the tangent angle is defined as an acute angle formed by a corresponding tangent on the curve 210 and the x coordinate axis. For example, as shown in Figure 2, the set positions of triangular prisms TP _A , TP _B , and TP _C correspond to three points A, B, and C on curve 210 respectively, and as shown in the figure, the bottom of triangular prism TP _A Angle θ ₁ equals the tangent angle θ ₁ of point A on the curve 210, the base angle θ ₂ of the triangular prism TP _B equals the tangent angle θ ₂ of the B point on the curve 210 and the base angle θ ₃ of the triangular prism TP _C equals the curve 210 The tangent angle θ ₃ of point C on .

The curve 210 shown in FIG. 2 is a continuous curve, but according to different types of light source 110 and the distance between the optical film 120 and the light source 110, the curve 210 can be composed of several curves, or can be a different curve. continuous curve.

的设计用来使得入射光经过棱镜面S₂的折射以及棱镜面S₁的全反射之后，可以垂直射出光学膜片的另一表面；然而，当棱镜结构122上的三角棱镜位于距离光源较近的位置时，以三角棱镜TP_B为例(图3C为图3A中包含三角棱镜TP_B的部分结构放大示意图)，其另一底角的设计用来使得大部分的入射光只经过棱镜面S₁，而入射光经由棱镜面S₁折射后可以垂直射出光学膜片的另一表面。The base angle of the above-mentioned triangular prism is determined according to the tangent angle of the curve 210, wherein the base angle is the base angle farther from a central line of the section of the prism structure 122 among the two base angles where the triangular prism contacts the optical film 120. The other base angle of each triangular prism is determined by the distance between the triangular prism and the light source 110 and whether the prism structure 122 faces the light source 110 . 3A-3C are schematic views of determining another base angle of the triangular prism when the prism structure 122 faces the light source 110 . As shown in Figures 3A _- 3C, when the triangular prism on the prism structure 122 is located at a position far away from the light source, take the triangular prism TP _A as an example (Fig. ), the other bottom corner of which

The design is used to make the incident light pass through the refraction of the prism surface _S2 and the total reflection of the prism surface _S1 , and then it can exit the other surface of the optical film vertically; however, when the triangular prism on the prism structure 122 is located closer to the light source When the position of the triangular prism TP _B is taken as an example (Fig. 3C is an enlarged schematic diagram of a part of the structure including the triangular prism TP _B in Fig. 3A), the other base angle is designed so that most of the incident light only passes through the prism surface S ₁ , and the incident light can exit the other surface of the optical film vertically after being refracted by the prism surface S ₁ .

的设计使得入射光在经过光学膜片的另一表面的折射之后，只会接触到棱镜面S₁而不会接触到棱镜面S₂，之后入射光在经由棱镜面S₁折射后可以垂直射出光学膜片的表面。However, when the prism structure 122 faces away from the light source 110, the other base angle of the triangular prism is determined in a different manner. 4A and 4B are schematic diagrams of determining another base angle of the triangular prism when the prism structure 122 faces away from the light source 110 . As shown in Fig. 4A and Fig. 4B (Fig. 4B is the enlarged schematic view of the partial structure comprising triangular prism TP _D in Fig. 4A), another base angle of triangular prism TP _D

The design makes the incident light only touch the prism surface S ₁ but not the prism surface S ₂ after being refracted by the other surface of the optical film, and then the incident light can be emitted vertically after being refracted by the prism surface S ₁ The surface of the optical film.

In addition, in the existing prism sheet, one surface of the prism sheet is a prism structure, while the other surface is a transparent plane with high penetration. However, in the embodiment of the present invention, the other surface of the optical film 120 It can be a translucent transparent plane or a matte structure with a diffusion effect. Using a matte structure on the other surface of the optical film 120 can make the incident light have light concentration and light uniformity after passing through the optical film 120 Effect.

In addition, the material of the optical film 120 can be a polarizing optical material, which can pre-polarize the light, and then achieve the effect of increasing the brightness of the panel by matching with a polarizer.

Furthermore, according to the different types of the light source 110 in the backlight module, the number of the optical film 120 used and the position relative to the light source 110 will also be different. FIG. 5 is a schematic diagram of relative positions of the optical film 120 and the line light source 510 when the light source is a line light source 510 . As shown in FIG. 5 , the line light source 510 is located on an extension plane SS of the centerline of the prism structure, and the extension plane SS is perpendicular to the optical film 120 .

FIG. 6 is a schematic diagram of the relative positions of the optical film 120 and the point light source 610 when the light source is a point light source 610 . As shown in FIG. 6 , a plurality of extension planes SS ₁ , SS ₂ , and SS ₃ corresponding to the centerlines of the two optical films 120_1 and 120_2 form a plurality of intersection lines, and the extension planes SS ₁ , SS ₂ , SS ₃ are perpendicular to the optical films 120_1 and 120_2, and the point light source 610 is located on the multiple intersection lines.

In addition, the backlight module 100 in the embodiment of the present invention does not need to use a diffuser, that is, the light from the light source 110 will directly irradiate the optical film of the present invention. However, in other embodiments, the backlight module 100 can also be Add a diffuser with a low fog structure to enhance the uniformity of the light.

As mentioned above, applying the backlight module of the present invention to a liquid crystal display can increase the light uniformity of the display panel on the liquid crystal display without using a diffusion sheet, thereby reducing the manufacturing cost of the display. The loss of light energy is reduced, thereby increasing the brightness of the light incident on the display panel.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims (20)

1. A backlight module comprising: At least one optical film includes at least one prism structure on one surface, and a plurality of triangular prisms are respectively arranged at a plurality of prism setting positions on the prism structure, and a base angle of each triangular prism is defined by the prism setting position of the triangular prism The slope of the curve corresponding to a curve is determined, and the base angle is the base angle of the two base angles where the triangular prism is in contact with the optical film, which is farther from a center line of the cross-section of the prism structure; and A light source is arranged on one side of the optical film along the central line. 2. The backlight module as claimed in claim 1, wherein the other surface of the optical film comprises a fog structure having a diffusion effect. 3. The backlight module as claimed in claim 1, wherein the coordinate axis of the curve corresponds to the coordinates of the multiple prisms on the cross-section of the prism structure, and the base angle of each triangular prism is equal to that on the curve corresponding to The tangent angle of the prism setting position of the triangular prism, and the tangent angle is an acute angle formed by a corresponding tangent defined by the curve and the coordinate axis. 4. The backlight module as claimed in claim 1, wherein the material of the optical film is a polarized optical material. 5. The backlight module as claimed in claim 1, wherein the curve is symmetrical to the centerline of the section of the prism structure. 6. The backlight module as claimed in claim 1, wherein the curve is a continuous curve or a discontinuous curve. 7. The backlight module as claimed in claim 1, wherein the light source is a line light source located on a plane extending parallel to the centerline of the cross-section of the prism structure. 8. The backlight module as claimed in claim 7, wherein the extending plane is perpendicular to the optical film. 9. The backlight module as claimed in claim 1, wherein a plurality of intersection lines are formed by corresponding extension planes of the centerlines of the two optical films, and the plurality of extension planes are all perpendicular to the optical film. 10. The backlight module as claimed in claim 9, wherein the light source is a point light source located on the intersection line. 11. A liquid crystal display comprising: At least one optical film includes at least one prism structure on one surface, and a plurality of triangular prisms are respectively arranged at a plurality of prism setting positions on the prism structure, and a base angle of each triangular prism is defined by the prism setting position of the triangular prism The slope of the curve corresponding to a curve is determined, and the base angle is the base angle of the two base angles where the triangular prism is in contact with the optical film, which is farther from a center line of the cross-section of the prism structure; A light source is arranged on one side of the optical film along the center line; and a display panel; The light emitted by the light source is directly irradiated onto the optical film. 12. The liquid crystal display as claimed in claim 11, wherein the other surface of the optical film comprises a fog structure having a diffusion effect. 13. The liquid crystal display as claimed in claim 11, wherein the coordinate axis of the curve corresponds to the coordinates of the plurality of prism installation positions on the cross section of the prism structure, and the base angle of each triangular prism is equal to the corresponding on the curve The tangent angle of the prism setting position of the triangular prism, and the tangent angle is an acute angle formed by a corresponding tangent defined by the curve and the coordinate axis. 14. The liquid crystal display as claimed in claim 11, wherein the material of the optical film is a polarized optical material. 15. The liquid crystal display as claimed in claim 11, wherein the curve is symmetrical to the centerline of the cross-section of the prism structure. 16. The liquid crystal display as claimed in claim 11, wherein the curve comprises a continuous curve or a discontinuous curve. 17. The liquid crystal display as claimed in claim 11, wherein the light source is a line light source located on a plane extending parallel to the centerline of the cross-section of the prism structure. 18. The liquid crystal display as claimed in claim 17, wherein the extending plane is perpendicular to the optical film. 19. The liquid crystal display as claimed in claim 11, wherein a plurality of intersection lines are formed by corresponding extension planes of the centerlines of the two optical films, and the plurality of extension planes are all perpendicular to the optical film. 20. The liquid crystal display as claimed in claim 19, wherein the light source is a point light source located on the intersection line.

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