Modulation circuit, image display using the same, and modulation method

摘要

A modulation circuit capable of high resolution pulse width modulation while keeping down the bit length and an image display provided with the modulation circuit. By the A/D converter 4, the video signal Sv converted into a binary code having a preset bit length is divided into a plurality of binary codes by the controller 3 from the most significant bit to the least significant bit. Corresponding to the thus obtained plurality of divided binary codes, serial data is generated for producing a pulse current of a pulse width and current value according to the value of the binary code and is output to pulse width modulation circuits 1 cascade connected to the controller 3. The pulse width modulation circuits supply LEDs 3 of the pixels pulse currents of pulse widths and current values corresponding to the serial data.