Patent · US Expired

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

US6646654B2 · kind B2 · utility

19Cited by
11References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateApr 20, 2001
Grant dateNov 11, 2003
Priority date
Expiry dateJun 21, 2021

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG09G2320/0247
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.