Backlight and liquid crystal display device

Abstract

A backlight includes a case having plural apertures in a main face thereof and a light source disposed in the case. A total area of the plural apertures is not less than 8% and not more than 15% of an area of the main face.

What is claimed is: 
     
         1 . A backlight comprising:
 a case having two or more apertures in a main face thereof; and   a light source disposed in the case,   wherein a total area of the apertures is not less than 8% and not more than 15% of an area of the main face.   
     
     
         2 . A backlight comprising:
 a case having two or more apertures in a main face thereof;   a light source disposed in the case; and   N kinds of filters (N is a positive integer) to have selectivity of wavelength and to be disposed on the apertures,   wherein a total area of the apertures is not less than 8×N % and not more than 15×N % of an area of the main face.   
     
     
         3 . The backlight according to  claim 2 , wherein the filters are of interference type. 
     
     
         4 . The backlight according to  claim 3 , wherein an inside wall face of the case includes at least one of an aluminum layer, a silver layer, and a dielectric multilayer. 
     
     
         5 . A backlight comprising:
 a case;   a light source disposed in the case; and   a filter of interference type to be disposed in a main face of the case,   wherein
 the filter includes N kinds of membranes (N is a positive integer) which is periodically aligned; 
 the membranes are formed so that adjacent membranes are partially overlapped; 
 the membranes allow permeation of light within a fixed wavelength range and reflect light within a range of other wavelength in accordance with the kinds of the membranes; and 
 a total area of parts which do not overlap with the adjacent membrane of the membranes is not less than 8×N % and not more than 15×N % of an area of the main face on which the filter is disposed. 
   
     
     
         6 . A liquid crystal display device comprising:
 a liquid crystal panel including:
 a pair of substrates; and 
 a liquid crystal layer held between the pair of substrates; 
   a backlight including:
 a case having two or more apertures in a main face facing the liquid crystal panel; 
 a light source disposed in the case; and 
 N kinds of filters to have selectivity of wavelength and to be disposed on the apertures (N is a positive integer), 
   wherein
 a total area of the apertures is not less than 8×N % and not more than 15×N % of an area of the main face of the case facing the liquid crystal panel. 
   
     
     
         7 . A liquid crystal display device comprising:
 a liquid crystal panel including:
 a pair of substrates; and 
 a liquid crystal layer held between the pair of substrates; and 
   a backlight including:
 a case; 
 a light source disposed in the case; and 
 a filter of interference type disposed on a main face of the case facing the liquid crystal panel, 
   wherein
 the filter includes N kinds of membranes which are periodically aligned (N is a positive integer); 
 the membranes are formed so that adjacent membranes partially overlap with each other; 
 the membranes allow permeation of light within a fixed wavelength range and reflect light within a range of other wavelength in accordance with the kinds of the membranes; and 
 a total area of parts which do not overlap with the adjacent membrane of the membranes is not less than 8×N % and not more than 15×N % of an area of the main face of the case on which the filter is disposed.