Liquid crystal display device having a light path changing means having a porus film with a plurality of pores

Abstract

Disclosed is a liquid crystal display device capable of improving a viewing angle thereof while reducing a gray scale inversion. The liquid crystal display device has a porous film aligned on a liquid crystal display panel and having a plurality of pores. The porous film has sidewalls defined by the pores and reflecting a part of light exited from the liquid crystal display panel. That is, the sidewalls reflect a first group of light, which has relatively higher luminance by passing through a short axis of liquid crystal, towards a second group of light having a relatively lower luminance by passing through a long axis of liquid crystal. Accordingly, the viewing angle of the liquid crystal display device is expanded and the gray scale inversion is reduced.

1 . A liquid crystal display device comprising: 
 a liquid crystal display panel for receiving a first light, and for radiating a second light having an image information, the liquid crystal display panel including: i) a first substrate on which a plurality of pixels having a first electrode is formed, ii) a second substrate on which a second electrode opposite to the first electrode is formed, and iii) a liquid crystal layer, disposed between the first and second substrate, which is aligned by an electric field applied between the first and second electrodes; and    a polarizing plate disposed on the liquid crystal display panel, the polarizing plate including i) a polarizing layer for polarizing the second light, and ii) a light patch changing layer including a reflection surface, the reflection surface for reflecting a part of the second light and outputting a third light having a compensated luminance, the reflection surface extended in a first direction perpendicular to an upper surface of the liquid crystal display panel, wherein the light path changing layer is disposed on a lower surface of the polarizing layer.    
   
   
       2 . A liquid crystal display device comprising: 
 a liquid crystal display panel for receiving a first light, and for radiating a second light having an image information, the liquid crystal display panel including: i) a first substrate on which a plurality of pixels having a first electrode is formed, ii) a second substrate on which a second electrode opposite to the first electrode is formed, and iii) a nematic liquid crystal, disposed between the first and second substrate, for being aligned by an electric field applied between the first and second electrodes; and    a polarizing plate disposed on the liquid crystal display panel, the polarizing plate including: i) a polarizing layer for polarizing the second light, and ii) a light path changing layer including a reflection surface, the reflection surface having a plurality of pores and inner sidewalls adjacent to each of the pores, the inner sidewalls reflecting a part of a first group of light of the second light towards a second group of light of the second light, the first group of light of the second light passing through the nematic liquid crystal in a parallel direction with regard to a first axis of the nematic liquid crystal tilted at a predetermined angle by the electric field, the second group of light of the second light passing through the nematic liquid crystal in a parallel direction with regard to a second axis of nematic liquid crystal, and the second axis being perpendicular to the first axis of nematic liquid crystal, wherein the first group of light of the second light has luminance higher than luminance of the first group of light, and wherein the light path changing layer is disposed on a lower surface of the polarizing layer.    
   
   
       3 . A liquid crystal display device comprising: 
 a lower substrate including: i) a plurality of switching devices arranged in a matrix shape on a first substrate, ii) a first electrode electrically coupled to the switching devices, and iii) a first alignment layer deposited on the first substrate and having a first rubbing pattern extended in a first direction;    an upper substrate including: i) a color filter formed on a second substrate, ii) a second electrode formed on the color filter, and iii) a second alignment layer deposited on the second electrode and having a second rubbing pattern extended in a second direction;    a liquid crystal layer disposed between the upper and lower substrates;    a first polarizing means, disposed on a lower surface of the lower substrate, for polarizing a first light incident into the lower substrate; and    a second polarizing means, disposed on the upper substrate, for polarizing a second light exited from the upper substrate, and for reflecting a part of the second light to output a third light having a compensated luminance, wherein the first polarizing means includes a first polarizing layer having a first transmission axis parallel to the second direction, and the second polarizing means includes a second polarizing layer having a second transmission axis parallel to the first direction, and wherein the second polarizing means includes a porous layer having a plurality of pores and sidewalls being defined by the pores, the porous layer reflects a part of the second light to output the third light having a compensated luminance distribution and provides the third light to the second polarizing layer, and the second light is incident into the sidewalls of the light path changing means.