Light guide plate, method of manufacturing the same, and liquid crystal display device including the same

Abstract

A light guide plate includes a light incident surface to which light is incident as incident light, an opposite surface formed opposite to the light incident surface, a light emitting surface through which the incident light is emitted, a rear surface formed opposite to the light emitting surface and including a prism pattern which reflects the incident light to the light emitting surface, and lateral surfaces, wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness at both the opposite surface and the light incident surface substantially uniform.

1 . A light guide plate comprising:
 a light incident surface to which light is incident as incident light;   an opposite surface formed opposite to the light incident surface;   a light emitting surface through which the incident light is emitted;   a rear surface formed opposite to the light emitting surface and including a prism pattern to reflect the incident light to the light emitting surface; and   lateral surfaces,   wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness adjacent both the opposite surface and the light incident surface substantially uniform.   
   
   
       2 . The light guide plate of  claim 1 , wherein an area of the diffuse reflection pattern is reduced as a distance increases from the light incident surface toward the opposite surface. 
   
   
       3 . The light guide plate of  claim 2 , wherein the diffuse reflection pattern has an average roughness decreased as a distance increases from the light incident surface toward the opposite surface. 
   
   
       4 . The light guide plate of  claim 3 , wherein the diffuse reflection pattern is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface. 
   
   
       5 . The light guide plate of  claim 1 , wherein the prism pattern comprises a plurality of intaglio prism lines extending substantially parallel to the light incident surface. 
   
   
       6 . The light guide plate of  claim 5 , wherein a size of the intaglio prism lines gradually increases as a distance increases from the light incident surface toward the opposite surface. 
   
   
       7 . The light guide plate of  claim 6 , wherein the size of at least any one of the intaglio prism lines formed in a region adjacent to the opposite surface decreases as a distance increases from the lateral surfaces to a central region thereof. 
   
   
       8 . The light guide plate of  claim 5 , wherein the light emitting surface further comprises a second prism pattern including a plurality of relief prism lines, in which a groove and a projection are repeatedly formed, and which extend in a direction crossing a direction of extension of the intaglio prism lines. 
   
   
       9 . The light guide plate of  claim 1 , wherein the rear surface further comprises at least one reflection pattern formed in a prism shape between prism lines of the prism pattern to reflect light to the light emitting surface. 
   
   
       10 . The light guide plate of  claim 9 , wherein the reflection pattern is formed within a region of the rear surface occupying about 10% of a length between the lateral surfaces, and the region is disposed adjacent at least one of the lateral surfaces. 
   
   
       11 . The light guide plate of  claim 10 , wherein the reflection pattern is formed in any one of relief and intaglio patterns. 
   
   
       12 . The light guide plate of  claim 11 , wherein the reflection pattern has a vertex angle in a range of about 130° to about 140°. 
   
   
       13 . The light guide plate of  claim 12 , wherein the reflection pattern has a height in a range of about 1 μm to about 10 μm from the rear surface and a width in a range of several tens to several hundreds of micrometers. 
   
   
       14 . The light guide plate of  claim 13 , wherein a number of reflection patterns increases as a distance increases from the light incident surface toward the opposite surface. 
   
   
       15 . The light guide plate of  claim 13 , wherein at least any one of the height and the width of the reflection pattern gradually increases as a distance increases from the light incident surface toward the opposite surface. 
   
   
       16 . A liquid crystal display device comprising:
 a liquid crystal panel displaying an image;   a light source generating light; and   a light guide plate including a light incident surface to which the light supplied from the light source is incident as incident light, an opposite surface formed opposite to the light incident surface, a light emitting surface through which the incident light is emitted, a rear surface formed opposite to the light emitting surface and including a prism pattern which reflects the incident light to the light emitting surface, and lateral surfaces, wherein a diffuse reflection pattern is formed on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness at both the opposite surface and the light incident surface substantially uniform.   
   
   
       17 . The liquid crystal display device of  claim 16 , wherein the diffuse reflection pattern of the light guide plate is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface. 
   
   
       18 . The liquid crystal display device of  claim 17 , wherein the prism pattern is formed with a plurality of intaglio prism lines extending substantially parallel to the light incident surface on the rear surface, and wherein a height of the intaglio prism lines formed in a region adjacent to the opposite surface decreases as a distance increases from the lateral surfaces to a central region thereof. 
   
   
       19 . The liquid crystal display device of  claim 18 , wherein the light guide plate further comprises at least one reflection pattern projected in a prism shape from the rear surface. 
   
   
       20 . A method of manufacturing a light guide plate, the method comprising:
 forming a light incident surface to which light is incident, an opposite surface formed opposite to the light incident surface, a light emitting surface through which incident light is emitted, a rear surface formed opposite to the light emitting surface, and lateral surfaces;   forming a prism pattern including a plurality of intaglio prism lines on the rear surface; and   forming a diffuse reflection pattern on at least any one of the light emitting surface and the lateral surfaces to diffuse-reflect light incident to the lateral surfaces, thus rendering a brightness at both the opposite surface and the light incident surface substantially uniform.   
   
   
       21 . The method of  claim 20 , where, in forming the diffuse reflection pattern, the diffuse reflection pattern is formed in a range of about 80% to about 95% of a length from the light incident surface to the opposite surface. 
   
   
       22 . The method of  claim 20 , wherein forming the prism pattern including a plurality of intaglio prism lines on the rear surface further comprises forming a reflection pattern in any one of relief and intaglio patterns on the rear surface to reflect light incident between the intaglio prism lines to the light emitting surface.