Patent · US Expired

Method for forming multi-color toner image

US4822702A · kind A · utility

8Cited by
2References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 15, 1982
Grant dateApr 18, 1989
Priority date
Expiry dateOct 15, 2002

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G13/013
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A toner of a first color incorporated into a development appartaus for second color is charged to a polarity opposite to a polarity of a charge of an electrostatic latent image for the second color by a frictional action with a toner in the development apparatus for the second color. The toner of the first color incorporated into the second development apparatus is caused to adhere to a charge-non-released region of a drum, whereby accumulation of the first toner in the second color development apparatus is prevented. The first and second toners are electrostatically transferred onto a paper by a bias electric field having a polarity opposite to that of the toner images, whereby at reversal development of the second color, the toner of the first color adhering to the charge-non-released region is prevented from being transferred onto the paper. Further, the toner of the first color, incorporated in the second development apparatus, changed reversly in its polarity, or reduced to about zero in the charge quantity can be removed by electrical and mechanical removal means provided in the second development apparatus.

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