| 摘要 |
PROBLEM TO BE SOLVED: To adjust surface luminances of the whole display device while having a multilevel displaying function in a pixel unit by multiplying surface luminance adjustment data to multilevel input data and controlling the lighting cumulative time of an LED by the calculation result. SOLUTION: Decoder for X line display 12 controls a transformation RAM 20 so as to determine an LED lighting cumulative time in accordance with a data quantity from write data to be stored in the X-Y transformation RAM 20. Moreover, the decoder 12 controls the output circuit of the RAM 20 to output a signal having the LED lighting cumulative time as a pulse width with one output line among 16 lines of output lines according to respective X lines X1∼X16. Further, a counter 13' transmits a timing signal to a decoder for X line display 12 so as to perform the changeing over of the 16 lines of output lines in synchronization with the can clock from a scan clock terminal 46 and the horizontal synchronizing signal from a horizontal synchronizing signal terminal 44. Thus, the surface luminance adjusting function of a low-speed display clock which has the multilevel displaying function of the pixel unit and which is of high accuracy and is miniaturized is obtained.
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