Patent · US Expired

Developing device

US4669859A · kind A · utility

11Cited by
10References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 22, 1983
Grant dateJun 2, 1987
Priority date
Expiry dateMar 22, 2003

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/065
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A developing device for developing an electrostatic latent image formed on an imaging surface includes a developing electrode disposed opposite to the imaging surface and a control circuit for controlling the potential of the developing electrode. In one form, when the control circuit causes the developing electrode to be electrically floating, the upper limit of the voltage excursion is set at different levels as desired. In another form, the control circuit includes a sensor for sensing the potential of the imaging surface thereby allowing to carry out so-called fixed bias or auto-bias developing modes. In a further form, the mode of developing operation is automatically set depending upon the position of a pressure plate which is to be placed on an original for keeping the original in position during copying process.

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