Patent · US Expired

Image forming apparatus

US4914459A · kind A · utility

37Cited by
1References
11Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 14, 1989
Grant dateApr 3, 1990
Priority date
Expiry dateApr 14, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/00054
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

An electrophotographic copier, facsimile machine, laser printer or similar image forming apparatus for reproducing an image on a paper sheet by transforming an image signal representative of the image into an image forming signal by pulse width modulation, causing a spot beam in the form of a laser beam which is modulated by the image forming signal to scan a photoconductive element to form an electrostatic latent image thereon, developing the latent image to render it visible, and transferring the visible image to a paper sheet. The laser beam output, the set pulse widths of the image forming signal (beam turn-on times) and the bias voltage for development are changed in association with the deterioration of the laser beam power and the sensitivity of the photoconductive element.

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