Patent · US Expired

Electrophotographic image forming apparatus comprising means for automatically adjusting image reproduction density

US5212560A · kind A · utility

15Cited by
6References
16Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 27, 1991
Grant dateMay 18, 1993
Priority date
Expiry dateNov 27, 2011

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH04N1/295
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

In an electrophotographic image forming apparatus, a corona charger electrically charges the photoconductor to a predetermined initial electric potential so as to supply an amount of electric charge thereto, and a laser projects a light onto the charged photoconductor so as to form an electrostatic latent image thereon. A light projecting controller controls the laser to change a light amount of the projected light according to an image density signal, and a developing device develops the formed electrostatic latent image with toner so as to form a toner image thereon. Then, a voltage generator applies a developing bias voltage to the developing device. Moreover, a density controller controls the corona charger and the voltage generator to change the amount of supplied electric charge and the developing bias voltage, and further controls the voltage generator so that a difference between the initial electric potential and the developing bias voltage becomes larger and a minimum light amount of first starting reproducing an image becomes smaller as the amount of supplied electric potential becomes larger.

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