Patent · US Expired

Electrophotographic image forming apparatus which controls developer bias based on image irregularity

US5227842A · kind A · utility

39Cited by
6References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 20, 1992
Grant dateJul 13, 1993
Priority date
Expiry dateMar 20, 2012

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/00042
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An image forming apparatus having a developing device of the type using a two-component type developer and developing an electrostatic latent image by a bias electric field having an alternating electric field. A predetermined reference latent image is electrostatically formed on an image carrier by a reference latent image forming device and then developed by the developing device to become a reference toner image. An irregularity detecting circuit determines the degree of difference between the density of the edge and the density of the central portion of the reference toner image. A bias electric field control circuit controls the bias electric field in matching relation to the output of the irregularity detecting circuit, thereby preventing the image quality from being degraded by a change in the resistance of the carrier.

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