Patent · US Expired

Pulse width control circuit

US4700367A · kind A · utility

15Cited by
4References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 16, 1985
Grant dateOct 13, 1987
Priority date
Expiry dateDec 16, 2005

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03K5/1502
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A pulse width control circuit for providing a control signal to adjust variations of electrical characteristics among a plurality of printing elements has an up/down counter and a plurality of control signal generating circuits. The up/down counter counts the number of pulses of a clock signal and delivers the counted value. The control signal generating circuit compares the counted values from the up/down counter with set values corresponding to conduction time periods of the currents used for driving light emitting diodes, and generates a plurality of control pulse signals having pulse widths whose central positions thereof are in accord with each other.

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