TWM522379U - High efficiency type optical film - Google Patents

Description

High efficiency optical film

The present invention relates to an optical film, and more particularly to a high efficiency optical film for a backlight module of a flat panel display.

Referring to FIG. 1 and FIG. 2, a conventional edge-lit backlight module 1 includes a reflective mask 11 , a light source 12 disposed in the reflective mask 11 , and a reflective mask 11 connected to the light source 12 . A light guide plate 13 on the side, a reflection sheet 14 disposed on the bottom of the light guide plate 13, and a lower diffusion sheet 15, a concentrating sheet 16, and an upper diffusion sheet 17 which are sequentially stacked from the light guide plate 13. The concentrating sheet 16 has a first substrate 261 and a plurality of first prisms 162 equally spaced on the first substrate 261. Each of the first prisms 162 is an isosceles triangular prism with an apex angle of 90° and is the same size as each other. The function of the first prisms 162 is to adjust the light path so that the light is concentrated toward a specific area, thereby enhancing the brightness of the front light.

However, a part of the light incident on the condensing sheet 16 is greatly deflected after being refracted by the first prism 162 in the shape of an isosceles triangle, and is emitted outside the front view of the flat display, that is, ±40. Outside the degree. In this case, in addition to the fact that the brightness of the front light is not improved, the light guide plate 13 cannot be recovered, and the light use rate is lowered, thereby degrading the quality of the flat display.

Therefore, the object of the present invention is to provide a high-efficiency optical film which can improve the efficiency of light use and thereby improve the brightness of the front surface of a flat panel display.

Thus, the novel high efficiency optical film comprises a substrate and a plurality of prisms. The substrate includes an opposite light incident surface and a light exiting surface, and the prisms are disposed on the light emitting surface of the substrate and have a triangular shape, and each of the prisms includes a first inclined surface extending obliquely from the light emitting surface away from the light emitting surface. And a second inclined surface extending obliquely from the light emitting surface and connected to the first inclined surface. Defining a normal to the light exit surface of the substrate, the first slope and the normal line define a first angle, the second slope and the normal line define a second angle, the angle of the first angle Between 35 degrees and 75 degrees, and the angle of the second angle is between 5 degrees and 35 degrees.

In some embodiments, the prisms have a refractive index between 1.48 and 1.62.

In some embodiments, the substrate has a refractive index of 1.66.

In some embodiments, the prisms are comprised of an ultraviolet curable resin.

In some embodiments, the material of the substrate is one of polyethylene terephthalate, polycarbonate, and polyethylene naphthalate.

In some embodiments, the substrate and the prisms are of unitary construction.

In some embodiments, the light incident surface of the substrate is a smooth surface or a rough surface.

The utility model has the advantages that the special prism angle design enables the light incident on the substrate to be controlled to emit light within an angle range not excessively deviating from the normal line, so as to achieve the effect of collecting light, thereby effectively improving the brightness of the front light.

Referring to FIG. 3, an embodiment of the novel high efficiency optical film includes a substrate 2 and a plurality of prisms 3. The substrate 2 includes an opposite light incident surface 21 and a light exit surface 22, and polyethylene terephthalate (PET), polycarbonate (PC) or poly It is prepared by polyethylene naphthalate (PEN), but it is not limited by the materials mentioned above, and other flexible and transparent can be selected without affecting the optical efficiency of the embodiment. The material, and in the present embodiment, the substrate 2 is made of PET.

The prisms 3 are light-emitting surfaces 22 provided on the substrate 2. Each of the prisms 3 is an asymmetrical non-isosceles triangle and includes a first slope 31 extending obliquely from the light exit surface 22 away from the light exit surface 22, and an oblique extension from the light exit surface 22 and connecting the first The second slope 32 of the slope 31. Defining a normal N perpendicular to the light exit surface 22 of the substrate 2, the first slope 31 and the normal N cooperate to define a first angle θ; the second slope 32 and the normal N cooperate to define a second The angle is ψ. The preferred angle of the first included angle θ is between 35 degrees and 75 degrees, and the preferred angle of the second included angle 介于 is between 5 degrees and 35 degrees. The prism 3 is obtained by imprinting an ultraviolet curing resin with a flexible mold having a surface shape complementary to the shape of the prisms 3. The method can control the shape of each prism 3 such that the angle of the first angle θ of each prism 3 is controlled between 35 degrees and 75 degrees, and the angle of the second angle ψ of each prism 3 is controlled at 5 degrees. Between 35 degrees.

The embodiment is mainly based on a special structural design, and an appropriate material is selected to achieve the effect of collecting light. The backlight module applied to a flat display can effectively improve the brightness of the front light. In detail, the prisms 3 have a special angular design, a prism 3 composed of an ultraviolet curing resin having a refractive index between 1.48 and 1.62, and the substrate 2 having a refractive index of 1.66, which can be 10 to 50. The light incident obliquely incident on the substrate 2 between the degrees is controlled to emit light within plus or minus five degrees of the normal N, thereby effectively improving the luminance of the front light.

In order to more clearly illustrate the characteristics of the present embodiment, the following table summarizes a plurality of sets of experimental data, wherein α and β respectively represent the incident light angle and the light exit angle when light enters the substrate 2; θ, ψ, n ₁ , and n ₂ indicates the angle of the first angle θ, the angle of the second angle 、, the refractive index of the substrate 2, and the refractive index of the prisms 3, respectively. <TABLE border="1"borderColor="#000000"width="_0001"><TBODY><tr><td></td><td> α </td><td>n<sub>1</Sub></td><td>n₂</td><td> θ </td><td> ψ </td><td> β </td></tr><tr><td> Specific Example 1 </td><td> 50° </td><td> 1.66 </td><td> 1.62 </td><td> 29° </td><td> 28° </td><td> 0° </td></tr><tr><td> Specific Example 2 </td><td> 40° </td><td> 1.66 </td><Td> 1.48 </td><td> 27.5° </td><td> 26° </td><td> 0° </td></tr><tr><td> Specific Example 3 </td ><td> 30° </td><td> 1.66 </td><td> 1.55 </td><td> 43° </td><td> 19° </td><td> 0° </td></tr><tr><td> Example 4 </td><td> 20° </td><td> 1.66 </td><td> 1.62 </td><td> 60° </td><td> 13° </td><td> 0° </td></tr><tr><td> Specific Example 5 </td><td> 10° </td><td > 1.66 </td><td> 1.48 </td><td> 70° </td><td> 7° </td><td> 0° </td></tr></TBODY></TABLE>

In summary, the novel high-efficiency optical film has a special prism angle design, so that the light incident on the substrate can be controlled to emit light within an angle range that does not deviate excessively from the normal N to achieve the effect of collecting light. Effectively enhance the brightness of the front light, so it can achieve the purpose of this new type.

However, the above is only the embodiment of the present invention, and when it is not possible to limit the scope of the present invention, all the simple equivalent changes and modifications according to the scope of the patent application and the contents of the patent specification are still This new patent covers the scope.

1‧‧‧Side-light backlight module
11‧‧‧Reflective mask
12‧‧‧Light source
13‧‧‧Light guide plate
14‧‧‧reflector
15‧‧‧Diffuser
16‧‧‧Spots
161‧‧‧First substrate
162‧‧‧first prism
17‧‧‧Upper diffuser
2‧‧‧Substrate
21‧‧‧Into the glossy surface
22‧‧‧Glossy
3‧‧‧ prism
31‧‧‧First slope
32‧‧‧Second slope
N‧‧‧Normal θ‧‧‧First angle ‧‧‧second angle

Other features and effects of the present invention will be apparent from the following description of the drawings. FIG. 1 is a side elevational view showing an existing one-side optical backlight module applied to a flat panel display; Is a partial perspective view illustrating a concentrating sheet of the edge-lit backlight module of FIG. 1; and FIG. 3 is a partial side elevational view of one embodiment of the novel high-efficiency optical film.

2‧‧‧Substrate

21‧‧‧Into the glossy surface

22‧‧‧Glossy

3‧‧‧ prism

31‧‧‧First slope

32‧‧‧second slope

N‧‧‧ normal

Θ‧‧‧first angle

Ψ‧‧‧second angle

Claims (7)

A high-efficiency optical film comprising: a substrate comprising an opposite light incident surface and a light exiting surface; and a plurality of prisms disposed on the light exit surface of the substrate and having a triangular shape, each prism comprising a light emitting surface a first inclined surface extending obliquely away from the light emitting surface direction and a second inclined surface extending obliquely from the light emitting surface and connected to the first inclined surface, defining a normal line perpendicular to a light emitting surface of the substrate, the first inclined surface and the normal line The first angle is defined by the cooperation, the second slope and the normal line define a second angle, the angle of the first angle is between 35 degrees and 75 degrees, and the angle of the second angle is between 5 degrees Degrees to between 35 degrees. The high efficiency optical film of claim 1, wherein the prisms have a refractive index between 1.48 and 1.62. The high-efficiency optical film according to claim 2, wherein the substrate has a refractive index of 1.66. The high-efficiency optical film according to claim 1, wherein the prisms are composed of an ultraviolet curable resin. The high-efficiency optical film according to claim 1, wherein the material of the substrate is one of polyethylene terephthalate, polycarbonate, and polyethylene naphthalate. The high-efficiency optical film according to claim 1, wherein the substrate and the prisms are of a unitary structure. The high efficiency optical film of claim 1, wherein the light incident surface of the substrate is a smooth surface or a rough surface.