KR20070100527A - Light guide panel for back light unit - Google Patents

Abstract

A light guide panel for a backlight unit is provided to prevent a bright line generated in a light entrance unit by light projected from a light source and improve a color difference and shadow generated in the light entrance unit, thereby improving a sight characteristic of a display apparatus such as LCD(Liquid Crystal Display). A light guide panel for a backlight unit on which a prism pattern is formed comprises the following parts: a light entrance unit(11); a prism pattern(12); and a light diffusion unit(20) for scatting light entered between the light entrance unit and a prism pattern area. A shape of the prism pattern is triangle. The prism pattern is vertically formed along light direction on a reflection surface of the light guide panel. The prism pattern is horizontally formed along light direction on an injection surface of the light guide panel.

Description

Light guide plate for backlight device {LIGHT GUIDE PANEL FOR BACK LIGHT UNIT}

1 is a plan view showing a bright line and a shadow portion generated in the light incident portion of the conventional light guide plate.

2 is a cross-sectional view showing the configuration of the present invention.

3 is a plan view showing a configuration of the present invention.

4 is a cross-sectional view showing the configuration of another embodiment of the present invention.

5 is a plan view showing the configuration of another embodiment of the present invention.

6 a) to d) are sectional views showing the construction of another embodiment of the present invention.

7 is a cross-sectional view showing the emission path of the incident light of the present invention.

      <Description of Signs of Major Parts of Drawings>

10: light guide plate 11: light receiving part

12: prism pattern 20: light diffusion means

21: scattering pattern 22: diffusion pattern

23: line attenuation pattern

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light guide plate for a backlight device, and more particularly, to a light guide plate for a backlight device that emits light emitted from a light source to an exit surface while advancing.

Generally, liquid crystal displays (LCDs), unlike CRTs (Cathode-Ray Tubes), are light-receiving devices that do not emit light on their own, and thus require a backlight device to maintain uniform brightness throughout the screen. Such a backlight device includes a light guide plate for inducing refraction or condensation of light to convert the first point light source or linear light source into a planar light source. The light guide plate is a plastic molding evolved into a concept of use in a transparent acrylic panel. The function of the light guide plate is to receive the light emitted from the light source, and to uniformly distribute the light to the pattern processing area in a predetermined area of the acrylic surface.

For reference, referring to the structure of the above-described conventional backlight device, a light source for generating light, a light guide plate that uniformly emits light incident from the light source, and a light disposed under the light guide plate to receive light incident from the light source A reflection sheet which prevents light from leaking and being lost to the lower portion of the light guide plate by reflecting upward from a liquid crystal panel, and a diffusion sheet disposed on opposite surfaces of the reflection sheet with the light guide plate therebetween to increase uniformity of light; It consists of vertical and horizontal prism sheets sequentially stacked on the upper surface of the diffusion sheet to derive the brightness of light by collecting the light diffused from the diffusion sheet, and a protective sheet to stabilize the color coordinates and protect the prism structure of the prism sheet. do. Among these, the light guide plate serves as a backlight that makes the liquid crystal panel part of the upper part bright by uniformly emitting light incident from the light source disposed at one end of the light guide plate, as described above. In order to uniformly emit light upward, various patterns are attached or engraved on the surface of the light guide plate to uniformly emit light flowing in the light guide plate upwardly.

When light enters such a light guide plate from the light source, as shown in FIG. 1, a bright line is formed in the light incident portion b of the light guide plate a. Since the light sources are typically three R, G, and B light sources, The difference between the shaded portion and the hue is generated such that the tip portion where light is incident and the light incident from the light source overlap each other are relatively bright and other portions are relatively dark. This is clearly shown in Figure 1 below.

[Figure 1] Illustration of overlapping lines

As such, when a bright line is formed in the light incident portion b of the light guide plate a, and a shaded portion and a hue difference occur, there is a problem that the visibility of the display surface is lowered. That is, the line and the shadow portion of the light irradiated from the light source are visually observed, which causes a difference in the degree of matching between the intensity and the light of the light.

The present invention for solving the above problems is an object of the present invention to provide a light guide plate for a backlight device with improved light line and visibility of the light incident portion.

In order to achieve the above object, the present invention provides a backlight light guide plate in which a prism pattern (PRISM PATTERN) is formed on a surface horizontally with respect to a light incident part. It is characterized by the provision of a diffusion means.

In the accompanying drawings, which are referred to before the detailed description of the present invention, FIG. 2 is a cross-sectional view showing the configuration of the present invention, FIG. 3 is a plan view showing the configuration of the present invention, and FIG. 4 is another embodiment of the present invention. 5 is a plan view showing the configuration of another embodiment of the present invention, Figure 6 a) to d) is a cross-sectional view showing the configuration of another embodiment of the present invention, Figure 7 It shows in a cross-sectional view showing the emission path of the incident light of the present invention.

The present invention will be described below with reference to the accompanying drawings.

First, as shown in the accompanying drawings, FIGS. 2 and 3, in the light guide plate 10 for a backlight in which a prism pattern 12 is formed on a surface of the light incident part 11, the light incident part 11 is provided. Between the and prism pattern 12 regions, light diffusion means 20 for diffusing through incident light scattering may be provided.

Here, in the present invention, the prism pattern 12 is preferably triangular, for example, but may be trapezoidal.

In this case, the prism pattern 12 is preferably formed perpendicular to the traveling direction of the light on the reflective surface of the light guide plate 10, but may be formed on the exit surface, may be formed on both sides, horizontally formed May be

In addition, the triangular shape, for example, the inclination angle of one side may be between 1 ° ~ 3 °, the vertex angle is preferably 80 ° ~ 160 °, the inclination angle of the light guide plate 10 according to the material and the illuminance of light It is also possible to vary the range of degrees and vertices.

In addition, the triangular shape may be, for example, an isosceles triangle shape.

In this case, when the prism pattern 12 is an isosceles triangle shape, it is preferable that the prism pattern 12 is formed perpendicularly to the direction of light traveling on the reflection surface of the light guide plate 10, but may be formed on the emission surface or both sides. It may be formed horizontally.

In addition, the isosceles triangle shape may be, for example, a vertex angle of 80 ° ~ 120 °.

Meanwhile, in the present invention, the light diffusing means 20 is provided in, for example, an area between the end of the light incident part 11 and one side end of the prism pattern 12, and the light diffusing means 20 is used to It may include a scattering pattern 21 for irregularly changing the advancing direction. Here, the scattering pattern 21 may be, for example, a scratch surface provided in the vertical or horizontal direction of the incident light, and may have a discontinuous shape and arrangement. In this case, the scattering pattern 21 is preferably formed directly on the surface of the light guide plate 10.

In addition, the light diffusing means 20 may include, for example, a diffusion pattern 22 for diffusing the light incident on the light incident part 11 and the light scattered through the scattering pattern 21. Here, the diffusion pattern 22 may be, for example, fine irregularities, may be a protrusion or groove of more than one standardized DOT shape including a point such as a circle or polygon or more, and may be provided in an irregular shape and arrangement. have. In this case, the area of the diffusion pattern 22 is preferably 30 μm to 60 μm, and the height or depth is preferably 2 μm to 20 μm, but is not limited thereto.

In addition, the diffusion pattern 22 may be provided on the surface of the scattering pattern 21, but may be provided in a region separate from the scattering pattern 21. In addition, the diffusion pattern 22 may be formed integrally with the light guide plate 10, but may be adhesively formed.

In addition, the light diffusing means 20 may include, for example, a line attenuation pattern 23 for reducing a line path of light incident on the light incident part 11, as shown in FIGS. 4 and 5. . Here, the line attenuation pattern 23 may be, for example, a sanded pattern. In addition, the line attenuation pattern 23 is preferably provided in the width 1/2 range of the region where the light diffusion means 20 is provided, it may be formed on the entire surface. In this case, when the line attenuation pattern 23 is provided in the width 1/2 range of the region where the light diffusion means 20 is provided, only the surface of the scattering pattern 21 and the diffusion pattern 22 or the diffusion pattern ( 22 may be provided only on the surface. Here, the linear attenuation pattern 23 may be formed by coating / gluing the particles of fine particles, and applying / adhering the surface of the light guide plate 10 or the scattering pattern 21 or / and the surface of the diffusion pattern 22. It can also be done.

The light diffusing means 20 may be provided on the reflective surface of the light guide plate 10 as shown in FIG. 6A of the accompanying drawings, and as shown in b) of FIG. 6, the light guide plate 10 may be provided. It may be provided on the exit surface of, or as shown in Figure 6c of the accompanying drawings, it may be provided on the reflective surface and the exit surface of the light guide plate 10. In addition, as shown in (d) of FIG. 6, the inner surface of the light guide plate 10 may be provided. For example, the diffusion means 22 may be formed in a groove shape into the light guide plate 10, or a protrusion and a groove shape may be combined.

Referring to the operation according to an embodiment of the present invention configured as described above are as follows. First, the light diffusion means 20, which is a main part of the present invention, is provided in an area between an end portion of the light incident portion 11 of the light guide plate 10 and one end of the prism pattern 12.

At this time, among the components of the light diffusing means 20, the scattering pattern 21 made of a discontinuous scratch surface provided in the vertical or horizontal direction and the traveling direction of the incident light is incident on the light incident part 11 It acts to change the direction of light irregularly.

In addition, among the components of the light diffusing means 20, the diffusion pattern 22 made of protrusions of irregular shape and DOT shape, the light incident on the light incident portion 11 and the scattering pattern 21. It acts to change / diffuse the propagation path of light scattered through).

Finally, among the components of the light diffusion means 20, the line attenuation pattern 23 formed of the sanded surface, serves to reduce the line path of the light incident on the light incident portion (11).

When the present invention having such a function to advance the light incident from the light source is as follows. First, as shown in FIG. 7, the light incident on the light incident part 11 of the light guide plate 10 is incident on the diffusion pattern 22 through the scattering pattern 21. Then, the light is scattered by the minute scratch surface of the scattering pattern 21, the light is changed path is reflected by the irregular dot-shaped projection of the diffusion pattern 22 to reduce the bright line. In addition, at this time, the sanding surface of the line attenuation pattern 23 reduces the traveling path of the line.

Although the preferred embodiment of the present invention has been described above, the present invention may use various changes, modifications, and equivalents. It is clear that the present invention can be applied in the same manner by appropriately modifying the above embodiments. Accordingly, the above description does not limit the scope of the invention as defined by the limitations of the following claims.

The present invention configured as described above, the irregular light diffusion means diffuses the light incident to the light incident portion through the irregular scattering, to improve the bright line generated in the light incident portion by the light irradiated from the light source, By improving the shade and color tone difference generated in the light incident part, the effect of improving the visibility of a display device such as an LCD is obtained.

Claims (25)

In the backlighting light guide plate 10 having the prism pattern 12 formed on the surface of the light incident part 11 horizontally, the light is diffused through scattering of incident light between the light incident part 11 and the prism pattern 12 region. The light guide plate for a backlight device, characterized in that to provide a light diffusion means (20). The light guide plate according to claim 1, wherein the prism pattern (12) has a triangular shape. The light guide plate according to claim 1, wherein the prism pattern (12) is formed perpendicular to the traveling direction of the light on the reflective surface of the light guide plate (10). The light guide plate according to claim 1, wherein the prism pattern (12) is formed on the exit surface of the light guide plate (10) and horizontally in the direction of light travel. The light guide plate according to claim 1, wherein the prism pattern (12) is formed on the reflection surface and the emission surface of the light guide plate (10) in the horizontal and vertical directions with respect to the direction of the light. The light guide plate according to claim 2, wherein the triangular shape of the prism pattern (12) has an inclination angle of 1 ° to 3 ° on one side thereof. The light guide plate according to claim 2, wherein the vertex angle of the triangular shape of the prism pattern (12) is between 80 ° and 160 °. The light guide plate according to claim 2, wherein the triangular shape of the prism pattern (12) is an isosceles triangle shape. The light guide plate according to claim 8, wherein the vertex angle of the isosceles triangle shape is between 80 ° and 120 °. The light guide plate according to claim 1, wherein the light diffusion means (20) is provided in an area between an end of the light incident part (11) and one end of the prism pattern (12). The light guide plate according to claim 1, wherein the light diffusing means (20) comprises a scattering pattern (21) for irregularly changing the traveling direction of the light incident on the light incident part (11). The light guide plate according to claim 11, wherein the scattering pattern (21) is a scratch surface that is provided in a vertical or horizontal direction to the propagation direction of incident light. The method of claim 1, wherein the light diffusion means 20 comprises a diffusion pattern 22 for diffusing the light incident on the light incident portion 11 and the light scattered through the scattering pattern 21. A light guide plate for a backlight device. The light guide plate according to claim 13, wherein the diffusion pattern (22) is minute unevenness. The light guide plate according to claim 13, wherein the diffusion pattern (22) is a projection of a shaped DOT shape such as a polygon in a circle or a triangle or more. The light guide plate according to claim 13, wherein the diffusion pattern (22) is a groove having a shaped DOT shape such as a polygon in a circle or a triangle or more. The light guide plate of claim 14, wherein the minute unevenness is formed in an irregular shape and arrangement. The light guide plate according to claim 15 or 16, wherein the standardized area of the diffusion pattern (22) is 30 µm to 60 µm, and the height is between 2 µm and 20 µm. The light guide plate according to claim 13, wherein the diffusion pattern (22) is provided on a surface of the scattering pattern (21). The light guide plate according to claim 1, wherein the light diffusion means (20) comprises a line attenuation pattern (23) for reducing a line path of light incident on the light incident part (11). The light guide plate according to claim 20, wherein the line attenuation pattern (23) is a sanded pattern. 21. The light guide plate according to claim 20, wherein the line attenuation pattern (23) is provided in a width 1/2 range of a region where the light diffusing means (20) is provided. The light guide plate according to claim 1, wherein the light diffusing means (20) is provided on a reflecting surface of the light guide plate (10). The light guide plate according to claim 1, wherein the light diffusing means (20) is provided on an exit surface of the light guide plate (10). The light guide plate according to claim 1, wherein the light diffusing means (20) is provided on the reflecting surface and the emitting surface of the light guide plate (10).

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