Luminance control method and luminance control circuit for organic EL display

Abstract

A luminance control method for an organic EL display comprises a first step of calculating a luminance accumulation value for each screen on the basis of a video input signal, and a second step of controlling the amplitude of the video input signal on the basis of the luminance accumulation value calculated in the first step and feeding to the organic EL display the video signal whose amplitude has been controlled.

1 - 11 . (canceled)  
   
   
       12 . In a portable telephone set comprising a camera having an automatic exposure control function and an organic electroluminescence display, 
 a portable telephone set characterized by comprising:    judgment means for judging peripheral brightness on the basis of exposure control information relating to the camera; and    display luminance control means for controlling the display luminance of the organic electroluminescence display on the basis of the peripheral brightness judged by the judgment means.    
   
   
       13 . The portable telephone set according to  claim 12 , characterized in that 
 the display luminance control means controls the display luminance of the organic electroluminescence display such that the display luminance of the organic electroluminescence display is reduced when the peripheral brightness judged by the judgment means is low, while being increased when the peripheral brightness judged by the judgment means is high.    
   
   
       14 . The portable telephone set according to  claim 12 , characterized in that 
 the exposure control information relating to the camera is one selected from exposure time information and AGC gain information.    
   
   
       15 . In a portable telephone set comprising an organic electroluminescence display, 
 a portable telephone set characterized by comprising:    detection means for detecting the direction of a display surface of the organic electroluminescence display; and    display luminance control means for controlling the display luminance of the organic electroluminescence display on the basis of the direction of the display surface of the organic electroluminescence display which is detected by the detection means.    
   
   
       16 . The portable telephone set according to  claim 15 , characterized in that 
 the display luminance control means controls the display luminance of the organic electroluminescence display such that the display luminance of the organic electroluminescence display is increased when the display surface of the organic electroluminescence display is directed upward, while being reduced when the display surface of the organic electroluminescence display is directed downward.