TWI407153B - Prism sheet and backlight module using the same - Google Patents

Abstract

The present invention relates to a prism sheet used for a liquid crystal display. The prism sheet is made of a transparent body. The transparent body includes a first surface and a second surface opposite to the first surface. A plurality of elongated-waved protrusions are formed on the first surface, and a plurality of micro-depressions are defined at the second surface. Each micro-depression includes four connecting sidewalls. A transverse width of each sidewall of each micro-depression progressively decreases with increasing distance from a bottom surface that is coplanar with the second surface. The present invention also provides a backlight module using the prism sheet. The backlight module has an improved light energy utilization ratio and brightness.

Description

Backlight module and its chip

The invention relates to a backlight module and a cymbal thereof, in particular to a backlight module for liquid crystal display and a cymbal thereof.

Referring to FIG. 1 , a conventional direct type backlight module 100 includes a frame 11 , a plurality of light sources 12 disposed inside the frame 11 , a diffusion plate 13 disposed above the light source 12 and covering the frame 11 , and A piece of film 10. The diffusing plate 13 generally contains scattering particles for diffusing light. The cymbal 10 includes a light incident surface 101 for receiving a light beam, a light exit surface 103 opposite to the light incident surface 101, and a plurality of elongated V-shaped projections 105 formed on the light exit surface 103.

In use, after the light generated by the complex light source 12 is uniformly diffused into the diffusing plate 13, it continues to enter the cymbal 10, and the emitted light is concentrated to some extent under the action of the elongated V-shaped projection 105 of the cymbal 10. Thereby, the brightness of the backlight module 100 within a certain viewing angle range is improved.

Referring to FIG. 2 and FIG. 3 together, the light becomes uniform after being diffused through the diffusion plate 13, but the angle at which the scattered light is incident on the cymbal 10 becomes messy. The disordered light enters the cymbal 10 and exits at the interface of the V-shaped protrusion 105. Part of the emitted light (such as a1, a2) is concentrated in a direction close to the vertical direction (ie, parallel to the Y-axis), and the portion of the emitted light can be emitted. Raising the brightness of the front side of the backlight module 100 Only part of the outgoing light (such as a3, a4) exits at the interface of the V-shaped protrusion 105 toward the horizontal direction (X-axis direction), and this part of the emitted light is not effectively utilized; in addition, there is still some light (such as a5, a6) After the refracting at the interface of the V-shaped protrusion 105, the slab 10 is re-entered, and the light energy loss is large during this process. In addition, the plurality of V-shaped protrusions 105 of the cymbal 10 are arranged in parallel, and the effect of focusing on the light mainly occurs on a plane perpendicular to the extending direction of the V-shaped protrusion 105; and the direction of extension of the V-shaped protrusion 105 The light in parallel planes has no aggregation, so that the part of the light is not effectively utilized.

In view of the above situation, it is necessary to provide a backlight module and a chip which can improve the effective utilization of light and high brightness.

A crotch panel comprising a transparent body, the transparent body comprising a first surface and a second surface opposite the first surface. The first surface of the transparent body has a plurality of elongated wave-shaped protrusions, and the second surface of the transparent body has a plurality of micro-grooves, each micro-groove comprising four inner sides connected in sequence, and a horizontal width of each inner side The second surface gradually decreases inwardly.

A backlight module includes a light source, a diffusion plate and a cymbal plate. The diffusion plate and the cymbal plate are sequentially disposed above the light source. The cymbal piece is composed of a transparent body, and the transparent body includes a first surface and the first The surface is opposite the second surface. The first surface of the transparent body has a plurality of elongated wave-shaped protrusions, and the second surface of the transparent body has a plurality of micro-grooves, each micro-groove comprising four inner sides connected in sequence, and a horizontal width of each inner side The second surface gradually decreases inwardly.

The first surface of the cymbal has a plurality of elongated undulating protrusions, and the second surface has a plurality of micro-grooves, and the plurality of elongated wavy protrusions on the first surface of the cymbal have a curved surface structure, The plurality of micro-grooves on the two surfaces have an inclined surface structure, and the curved surface structure cooperates with the inclined surface structure to cooperate with the light incident on the cymbal, so that the backlight module using the cymbal can improve the brightness of the emitted light and Use light more efficiently.

200‧‧‧Backlight module

20, 30, 40, 50‧‧‧ pictures

201, 401, 501‧‧‧ first surface

202, 402, 502‧‧‧ long strips of wavy protrusions

203, 303‧‧‧ second surface

204, 304‧‧‧ micro-groove

23‧‧‧Diffuser

22‧‧‧Light source

21‧‧‧Frame

100‧‧‧Backlight module

10‧‧‧ Picture

101‧‧‧Into the glossy surface

103‧‧‧Glossy surface

105‧‧‧V-shaped projection

11‧‧‧Frame

12‧‧‧Light source

13‧‧‧Diffuser

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

2 is a perspective view of a cymbal of the backlight module shown in FIG. 1.

Fig. 3 is a schematic view showing the light exiting along the III-III of the cymbal shown in Fig. 2.

4 is a cross-sectional view of a backlight module in accordance with a preferred embodiment of the present invention.

FIG. 5 is a perspective view of the cymbal of the backlight module shown in FIG. 4.

6 is a top plan view of the cymbal of the backlight module shown in FIG. 4.

Figure 7 is a plan view of a cymbal sheet of the preferred embodiment 2 of the present invention.

Figure 8 is a cross-sectional view of a third embodiment of the preferred embodiment of the present invention.

Figure 9 is a cross-sectional view of a crucible of a preferred embodiment of the present invention.

The backlight module and the cymbal of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

Referring to FIG. 4, a backlight module 200 according to a preferred embodiment of the present invention includes a die 20 and a diffusion plate 23 disposed on one side of the die 20 in sequence. The light source 22 and the frame 21 for accommodating the plurality of light sources 22, the cymbal 20 and the diffusing plate 23 cover the frame 21, and the light emitted by the light source 22 enters the diffusing plate 23 directly or through the reflection of the frame 21, and is diffused by the diffusing plate 23. Enter the cymbal 20 for aggregation.

Referring to FIGS. 5 and 6, the cymbal 20 is formed by a transparent body including a first surface 201 and a second surface 203 opposite the first surface 201. The first surface 201 has a plurality of elongated undulating protrusions 202, and the second surface 203 has a plurality of micro-grooves 204.

Referring to FIG. 4 and FIG. 5, the first surface 201 faces the diffuser plate 23, and the elongated wave-shaped protrusions 202 thereon are used to converge the light incident on the cymbal 20. The center-to-center spacing P of the adjacent elongated undulating protrusions 202 satisfies the following relationship: 0.025 mm P 1.5 mm.

Referring again to Figures 4 and 6, the second surface 203 faces away from the diffuser plate 23, and the micro-grooves 204 thereon serve to cause the light emerging from the cymbal 20 to agglomerate. The plurality of micro-grooves 204 are arranged closely in a regular array. Each of the micro-grooves 204 includes four interconnected inner sides, that is, the micro-grooves 204 have a quadrangular pyramid shape. The inner side of the micro-groove 204 is a pair of four isosceles triangles, wherein the angle between one pair of the isosceles triangles and the other two isosceles triangles may be different, but preferably between 60 degrees and 120 degrees. Within the range of degrees. In the horizontal direction, the center-to-center spacing P1 of the adjacent micro-grooves 204 satisfies the following relationship: 0.025 mm P1 1 mm; in the vertical direction, the center-to-center spacing P2 of the adjacent micro-grooves 204 satisfies the following relationship: 0.025 Millimeter P2 1 mm. By adjusting the angle of the angle and the aspect ratio of the microgrooves 204, the brightness enhancement and the exit angle of the cymbal 20 can be adjusted. .

The overall thickness of the crotch panel 20 can range from 0.5 mm to 3 mm. The cymbal sheet 20 may be injection molded from one or more of polymethyl methacrylate, polycarbonate, polystyrene, and styrene-methyl methacrylate copolymer. During the preparation process, a concave structure corresponding to the elongated undulating protrusions 202 and a corresponding convex structure of the micro-grooves 204 are provided on the mold, so that the cymbals 20 can be formed in a single injection molding process.

The frame 21 may be made of metal or plastic having high reflectivity or metal or plastic coated with a high reflectivity coating.

Light source 22 can be a line source or a point source, such as a light emitting diode and a cold cathode fluorescent lamp.

Since the plurality of elongated undulating protrusions 202 on the first surface 201 of the cymbal 20 have a varying curved surface structure, the plurality of micro-grooves 204 of the second surface 203 have an inclined surface structure, the curved surface structure and the inclined surface structure Cooperating with the light incident on the cymbal 20, it is easy to make the backlight module 200 using the cymbal 20 improve the brightness of the emitted light and more effectively utilize the light.

Specifically, in the embodiment, when the light enters the cymbal 20 from the first surface 201, since the first surface has a plurality of elongated wavy protrusions 202, the curved structure of the elongated wavy protrusions 202 gradually changes the light structure. A certain degree of convergence occurs in a direction perpendicular to the cymbal 20. When the light exits from the second surface 203, since the second surface 203 has a plurality of micro-grooves 204, the surface structure of the micro-grooves 204 is inclined such that the emergent rays are further concentrated in a direction perpendicular to the cymbals 20. Therefore, the brightness of the backlight module 200 can be greatly improved. At the same time, since the first surface 201 converges most of the light to a direction perpendicular to the cymbal 20 when the light enters the cymbal 20, when the light is emitted from the second surface 203, it is parallel to the cymbal 20. Less light is emitted, thereby reducing the light that is returned to the cymbal 20 again and allowing more light to be effectively utilized.

Further, since the micro-groove 204 of the second surface 203 is a quadrangular pyramid having four inner sides connected in order, the outgoing light can be effectively concentrated in the XZ plane or the YZ plane, thereby fully The light in all directions is used to further increase the brightness of the front surface of the backlight module 200.

In addition, the cymbal sheet 20 of the present invention is integrally molded by injection molding, and the conventional enamel sheet is formed by coating a resin film on a transparent plate to form a microstructure, and the cymbal sheet 20 is easier to achieve a faster amount than the two. Production and cost reduction; and when used, there is no light interface loss in the cymbal 20, which has higher light utilization. In addition, the conventional method applies a resin film on a transparent plate to form a microstructure, and since the bonding force of the coated resin film and the transparent plate is generally low and the resin film itself is difficult to form high strength, the microstructure is easily scratched and pressure-damped; However, the long wavy protrusions 202 and the micro-grooves 204 integrally formed by the injection molding method and the cymbal sheet 20 have corresponding structural strengths, which can avoid or reduce the risk of being damaged during use.

It will be appreciated that the second surface 203 can also be used to face the diffuser panel 23 with the first surface 201 facing away from the diffuser panel 23.

Referring to Figure 7, there is shown a die 30 of a preferred embodiment of the present invention.稜鏡 The sheet 30 is similar to the cymbal sheet 20 of the first embodiment except that the micro-grooves 304 of the second surface 303 are quadrangular-shaped grooves and there is a gap between the micro-grooves 304.

Please refer to FIG. 8 for a third embodiment of the present invention. The cymbal 40 is similar to the cymbal 20 of the first embodiment except that the first surface 401 has a plurality of elongated undulating protrusions 402, and the profile of the vertical section of the elongated undulating protrusions 402 is a parabola.

Referring to Figure 9, there is shown a topsheet 50 of a preferred embodiment of the present invention. The crotch panel 50 is similar to the crotch panel 20 of the first embodiment except that the first surface 501 has a plurality of elongated undulating protrusions 502, and the profile of the vertical section of the elongated undulations 502 is sinusoidal. . In other embodiments, the profile of the vertical section of the elongated undulations 502 is a curve formed by a triangular fillet.

It can be understood that, in the above-mentioned cymbal, the arrangement direction of the array of micro-grooves and the side of the cymbal may also be acute.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. However, the above description is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and those skilled in the art will be equivalently modified or changed in accordance with the spirit of the present invention. All should be covered by the following patent application.

200‧‧‧Backlight module

20‧‧‧ Picture

201‧‧‧ first surface

202‧‧‧Large wavy bulges

203‧‧‧ second surface

204‧‧‧Microgroove

21‧‧‧Frame

22‧‧‧Light source

23‧‧‧Diffuser

Claims (17)

A cymbal sheet comprising a transparent body, the transparent body comprising a first surface and a second surface opposite the first surface, wherein the first surface of the transparent body has a plurality of elongated undulations The protrusion has a second surface of the transparent body having a plurality of micro-grooves, each micro-groove comprising four inner sides connected in series, and a horizontal width of each inner side gradually decreases inward from the second surface. The bracts of claim 1, wherein the plurality of elongated undulating ridges are parallel to each other, and the center-to-center spacing of the adjacent elongate undulations is from 0.025 mm to 1.5 mm. The cymbal according to claim 1, wherein the profile of the vertical section of the elongated wavy protrusion is a curve formed by a sinusoidal curve, a parabola or a triangular fillet. The cymbal of claim 1, wherein the micro-groove is a quadrangular pyramid groove or a quadrangular lattice groove. The cymbal of claim 4, wherein the angle between the two opposite inner sides of each micro-groove is 60 degrees to 120 degrees. The cymbal of claim 1, wherein the adjacent micro-grooves have a center-to-center spacing of 0.025 mm to 1 mm. The bracts of claim 1, wherein the bracts have a thickness of from 0.5 mm to 3 mm. For example, the bracts described in the first paragraph of the patent application, wherein the bracts are made of poly One or more materials of methyl acrylate, polycarbonate, polystyrene, and styrene-methyl methacrylate copolymer are injection molded. A backlight module includes a light source, a diffusion plate and a cymbal plate. The diffusion plate and the cymbal plate are sequentially disposed above the light source. The cymbal piece is composed of a transparent body, and the transparent body includes a first surface and the first The surface is opposite to the second surface, and the improvement is that the first surface of the transparent body has a plurality of elongated wave-shaped protrusions, and the second surface of the transparent body has a plurality of micro-grooves, each micro-groove comprising four consecutive connections The inner side of each of the inner sides gradually decreases inwardly from the second surface. The backlight module of claim 9, wherein the first surface of the cymbal is facing the diffusion plate. The backlight module of claim 9, wherein the plurality of elongated undulating protrusions of the cymbal are parallel to each other, and a center-to-center spacing of the adjacent elongated wavy protrusions is 0.025 mm to 1.5 mm. The backlight module of claim 9, wherein the vertical cross-sectional profile of the plurality of elongated undulating protrusions of the cymbal is a curve formed by a sinusoidal curve, a parabola or a triangular fillet. The backlight module of claim 9, wherein the plurality of micro-grooves of the cymbal are quadrangular pyramid grooves or quadrangular lattice grooves. The backlight module of claim 13, wherein an angle between two opposite inner sides of each micro-groove is 60 degrees to 120 degrees. The backlight module of claim 9, wherein a center-to-center spacing of the adjacent micro-grooves of the cymbal is 0.025 mm to 1 mm. The backlight module of claim 9, wherein the thickness of the cymbal is The degree is from 0.5 mm to 3 mm. The backlight module of claim 9, wherein the cymbal sheet is one or more of polymethyl methacrylate, polycarbonate, polystyrene, and styrene-methyl methacrylate copolymer. The material is injection molded into a quality.