Patent · US Expired

Image forming apparatus

US5182575A · kind A · utility

29Cited by
16References
23Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 16, 1990
Grant dateJan 26, 1993
Priority date
Expiry dateOct 16, 2010

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N2201/0458
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

This disclosure relates to an image forming apparatus in which an image is formed by deflecting a light beam a minute distance in a sub-scanning direction every pixel of image data. By controlling the emission intensity of the light beam utilizing a .gamma. correction, and by controlling the emission time of the light beam utilizing PWM control, the beam spot can be adjusted to control the dot size of the image. Accordingly, the dot density in image formation can be raised by minute deflection in the sub-scanning direction, and the reproducibility of characters and graphics is improved, particularly in the oblique direction. Furthermore, tone reproducibility of multi-tone image data is enhanced by minute deflection in the sub-scanning direction and adjustment of image dot size.

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