Liquid crystal display device

Abstract

A liquid crystal display device of reduced power consumption has a liquid crystal display panel and at least a backlight unit disposed in opposition to a liquid crystal display part of the liquid crystal display panel. The surface of the backlight unit that is opposed to the liquid crystal display panel is divided into a plurality of subunits capable of being individually adjusted in brightness, and the liquid crystal display part is divided into pixel blocks which are surface portions opposed to the respective subunits. The liquid crystal display device includes a first unit for calculating the highest brightness from display data inputted to individual pixels in each of the pixel blocks, and a second unit for adjusting, according to the magnitude of the highest brightness calculated by the first means, the brightness of each of the opposed subunits.

1 . A liquid crystal display device comprising a liquid crystal display panel and a backlight unit, wherein 
 said liquid crystal display panel having a display area,    said backlight unit disposed in opposition to said display area, and being divided into a plurality of subunits capable of being individually adjusted in brightness,    said display area being divided into pixel blacks opposed to said respective subunits,    said liquid crystal display device adjusts a brightness of at least one of said subunits according to the display data inputted to corresponding pixel block.    
   
   
       2 . A liquid crystal display device according to  claim 1 , 
 wherein said backlight unit has a plurality of light-emitting elements.    
   
   
       3 . A liquid crystal display device according to  claim 2 , 
 wherein said light-emitting elements include light-emitting diodes of three kinds which respectively emit red, blue and green lights.    
   
   
       4 . A liquid crystal display device according to,  claim 3 , further comprising an optical sheet provided between said backlight unit and said liquid crystal display panel.  
   
   
       5 . A liquid crystal display device according to  claim 1 , 
 wherein said backlight unit is divided into a plurality of subunits arranged in one direction and in another direction intersecting said one direction.    
   
   
       6 . A liquid crystal display device according to  claim 1 , 
 wherein said backlight unit is divided into a plurality of subunits arranged in one direction.    
   
   
       7 . A liquid crystal display device comprising a liquid crystal display panel and a backlight unit, wherein 
 said liquid crystal display panel having a display area,    said backlight unit disposed in opposition to said display area, and being divided into a plurality of subunits capable of being individually adjusted in brightness,    said display area being divided into pixel blocks opposed to said respective subunits,    said liquid crystal display device calculates display data indicative of a highest brightness from display data inputted to individual pixels in each of the pixel blocks and increases a gray scale level of said display data inputted to each of said pixels of each of said pixel blocks according to said highest brightness of the corresponding one of said pixel blocks and decreases a brightness of the corresponding one of said subunits opposed to said respective pixel blocks according to said highest brightness of each of said pixel blocks.    
   
   
       8 . A liquid crystal display device according to  claim 7 , 
 wherein said magnitude of increase of the gray scale level of said display data is adjusted between white display and black display according to the brightness value of the highest brightness.    
   
   
       9 . A liquid crystal display device according to  claim 7 , 
 wherein said backlight unit has a plurality of light-emitting elements arranged on a surface opposed to said liquid crystal display panel.    
   
   
       10 . A liquid crystal display device according to  claim 7 , 
 wherein said backlight unit has a plurality of light-emitting diodes arranged on a surface opposed to said liquid crystal display panel and said light-emitting diodes include light-emitting diodes of three kinds which respectively emit red, blue and green lights.    
   
   
       11 . A liquid crystal display device according to  claim 10 , further comprising an optical sheet being provided between said backlight unit and said liquid crystal display panel.  
   
   
       12 . A liquid crystal display device according to  claim 7 , 
 wherein said backlight unit is divided into a plurality of subunits arranged in one direction and in another direction intersecting said one direction.    
   
   
       13 . A liquid crystal display device according to  claim 7 , 
 wherein said backlight unit is divided into a plurality of subunits arranged in one direction.    
   
   
       14 . A liquid crystal display device comprising a liquid crystal display panel and a backlight unit, wherein 
 said liquid crystal display panel having a display area,    said backlight unit being divided into a plurality of subunits capable of being individually adjusted in brightness,    said display area being divided into pixel blocks opposed to said respective subunits,    said liquid crystal display device extracts an arbitrary number of display data from at least one half of display data of higher brightness among all display data inputted to individual pixels of each of said pixel blocks, and calculates a brightness of each of said pixel blocks from a total brightness or an average brightness according to said extracted display data and adjusts a brightness of a corresponding one of the subunits opposed to the respective pixel blocks according to the magnitude of the brightness of each of said pixel blocks.    
   
   
       15 . A liquid crystal display device according to  claim 14 , 
 wherein said liquid crystal display device calculates said brightness according to gray scale levels of said extracted display data.    
   
   
       16 . A liquid crystal display device according to  claim 14 , 
 wherein said liquid crystal display device extracts one or more display data.    
   
   
       17 . A liquid crystal display device comprising a liquid crystal display panel and a backlight unit, wherein, 
 said liquid crystal display panel having a display area,    said backlight unit being divided into a plurality of subunits capable of being individually adjusted in brightness,    said display area being divided into pixel blocks opposed to said respective subunits,    said liquid crystal display device extracts an arbitrary number of display data from at least one half of display data of higher brightness among all display data inputted to individual pixels of each of the pixel blocks and calculates a brightness of each of said pixel blocks from a total brightness or an average brightness according to the extracted display data and increases a gray scale level of each of said display data inputted to said respective pixels of said pixel block itself according to said brightness of each of said pixel blocks and decreases the brightness of a corresponding one of said subunits opposed to said respective pixel blocks according to the brightness of each of said pixel blocks.    
   
   
       18 . A liquid crystal display device according to  claim 17 , 
 wherein said liquid crystal display device calculates said brightness according to gray scale levels of said extracted display data.