Patent · US Expired

Compensating driver circuit for thermal print head

US4305080A · kind A · utility

13Cited by
8References
4Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJul 18, 1979
Grant dateDec 8, 1981
Priority date
Expiry dateJul 18, 1999

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB41J2/365
  • WIPO fieldTextile and paper machines
  • WIPO sectorMechanical engineering

Abstract

A driver circuit for a thermal printing element varies the power applied to the element, depending upon its recent history of energization, in order to maintain uniform print density desprite temperature variation in the element. A capacitor charges and discharges to measure time intervals since the last element energization to control the voltage applied by an output transistor.

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