Display device, electronic apparatus using the same and light guider for display devices

Abstract

A TN liquid crystal 140 is used as a liquid crystal panel, and a polarizer 130 is provided above the TN liquid crystal 140 while a polarizer 135, a light scattering layer 150 and a polarized light splitter 160 are provided in this order under the TN liquid crystal 140. Furthermore, under the polarized light splitter 160, there is provided a light guide 190 for introducing light of a light source 191 from under the polarized light splitter 160 and a reflecting plate 200. The polarized light splitter 160 is a reflecting polarizer which can accomplish the effective utilization of light so that extremely bright reflective and transmissive displays are obtainable. Additionally, since a light diffusing layer 150 is provided, even if the distance from the TN liquid crystal 140 to the reflecting plate 200 is prolonged, in the reflective display, no double image nor display bleeding occurs.

1 . A display device characterized by comprising: 
 a liquid crystal panel in which a transmissive polarization axis is variable;    first and second polarized light splitting plates located on both sides of said liquid crystal panel to interpose said liquid crystal panel therebetween;    a reflecting layer located on the opposite side to said liquid crystal panel with respect to said second polarized light splitting plate;    a light source;    a light guider interposed between said second polarized light splitting plate and said reflecting layer for guiding light from said light source so that said light is incident through said second polarized light splitting plate on said liquid crystal panel and further for allowing transmission of light from said second polarized light splitting plate side and transmission of light from said reflecting layer side; and    a front scatterplate interposed between said liquid crystal panel and said reflecting layer for scattering forwardly each of light from said reflecting layer side toward said liquid crystal panel side and light from said liquid crystal panel side toward said reflecting layer side.    
     
     
         2 . A display device according to  claim 1 , characterized in that said front scatterplate is put between said liquid crystal panel and said light guider.  
     
     
         3 . A display device according to  claim 1 , characterized in that an optical anisotropy in said light guider is so low that it hardly has influence on display chrominance non-uniformity in said display device.  
     
     
         4 . A display device according to  claim 1 , characterized in that, in said light guider, an optical axis direction is constant.  
     
     
         5 . A display device according to  claim 1 , characterized by further comprising a third polarized light splitting plate provided between said second polarized light splitting plate and said light guider, 
 wherein said first polarized light splitting plate functioning as a polarized light splitting plate which transmits, absorbs or reflects incident light in accordance with polarized light component,    said second polarized light splitting plate functioning as a polarized light splitting plate which transmits, absorbs or reflects incident light in accordance with polarized light component,    said third polarized light splitting plate functioning as a polarized light splitting plate which transmits or reflects incident light in accordance with polarized light component, and    a direction of a polarization axis of said second polarized light splitting plate coinciding approximately with a direction of a polarization axis of said third polarized light splitting plate.    
     
     
         6 . A display device according to  claim 5 , characterized in that said third polarized light splitting plate is a polarized light splitting plate which reflects, of said incident light, a linearly polarized light component in a direction substantially perpendicular to the direction of said polarization axis of said third polarized light splitting plate.  
     
     
         7 . A display device according to  claim 6 , characterized in that said third polarized light splitting plate is a laminated member produced by piling up a plurality of layers closely, and refractive indexes of said plurality of layers are equal to each other between adjacent layers in one predetermined direction while being different from each other in another direction perpendicular to said one predetermined direction.  
     
     
         8 . A display device according to  claim 1 , characterized in that said liquid crystal panel is composed of a TN liquid crystal element, an STN liquid crystal element or an ECB liquid crystal element.  
     
     
         9 . A display device characterized by comprising: 
 a liquid crystal panel in which a transmissive polarization axis is variable;    first and second polarized light splitting plates located on both sides of said liquid crystal panel to interpose said liquid crystal panel therebetween;    a reflecting layer located on the opposite side to said liquid crystal panel with respect to said second polarized light splitting plate;    a light source; and    a light guider located between said second polarized light splitting plate and said reflecting layer for guiding light from said light source through said second polarized light splitting plate to said liquid crystal panel and further for allowing transmission of light from said second polarized light splitting plate side and light from said reflecting layer side, with said light guider having an optical anisotropy which is so low that it hardly has influence on display chrominance non-uniformity or with said light guider having a constant optical axis direction.    
     
     
         10 . A display device according to  claim 9 , characterized by further comprising a front scatterplate located between said liquid crystal panel and said reflecting layer for forwardly scattering each of light from said reflecting layer side toward said liquid crystal panel side and light from the liquid crystal panel side toward said reflecting layer side.  
     
     
         11 . A display device according to  claim 9 , characterized in that said first polarized light splitting plate is a polarized light splitting plate which transmits, absorbs or reflects incident light in accordance with polarized light component, 
 wherein said second polarized light splitting plate is a polarized light splitting plate which transmits, absorbs or reflects incident light in accordance with polarized light component.    
     
     
         12 . A display device according to  claim 9 , characterized in that said liquid crystal panel is composed of a TN liquid crystal element, an STN liquid crystal element or an ECB liquid crystal element.  
     
     
         13 . A display device according to  claim 1 , characterized by further comprising coloring means interposed between said first polarized light splitting plate and said light guider.  
     
     
         14 . A display device according to  claim 12 , characterized in that said coloring means is a color filter.  
     
     
         15 . A display device according to  claim 14 , characterized in that said color filter is composed of three colors of a red-based color, a green-based color and a blue-based color.  
     
     
         16 . A display device according to  claim 15 , characterized in that said three-color filter is made so that its average transmittance ratio is in a range of 30% to 80%.  
     
     
         17 . A display device according to  claim 9 , characterized by further comprising coloring means interposed between said first polarized light splitting plate and said light guider.  
     
     
         18 . An electronic apparatus incorporating said display device according to  claim 1 .  
     
     
         19 . An electronic apparatus incorporating said display device according to  claim 9 .  
     
     
         20 . An electronic apparatus incorporating said display device according to  claim 13 .  
     
     
         21 . An electronic apparatus incorporating said display device according to  claim 17 .  
     
     
         22 . A light guider for a display device, characterized by having an optical anisotropy so low in a plane as to exert little influence on display chrominance non-uniformity when used for a display device.  
     
     
         23 . A light guider for a display device, characterized by having a constant optical axis direction.