LIGHT EMITTING ARRAY DRIVING CIRCUIT

摘要

PURPOSE: To rapidly perform the uniformization of the light emitting quantities of light emitting elements or gradation control and to achieve the miniaturization of a circuit scale, the simplification of a control system and cost reduction. CONSTITUTION: Printing data Din are inputted to shift registers 31-1... to be latched by latch circuits 32-1.... The corresponding data of the light emitting quantities stored in a memory 50 are inputted to the shift registers 33-1.... Coincidence circuits 35-1... compare the count value of ring counters 34-1... with the corresponding data of the shift registers 33-1... and, when both of them coincide with each other the correction data are outputted. The count values are decoded by decode circuits 36-1... to be successively sent to sequential change-over circuits 37-1.... The sequential changeover circuits 37-1... and reference voltage generation parts 38-1... change over predetermined reference voltage successively according to the correction data held to the shift registers 33-1... to output the same. D/A converters 39-1... convert the correction data outputted from the coincidence circuits 35-1... to analogue values on the basis of the reference voltage to apply the same to driver parts 40-1....