Patent · US Expired

Development apparatus having a transport roll rotating at least twice the surface velocity of a donor roll

US5063875A · kind A · utility

21Cited by
5References
24Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 19, 1990
Grant dateNov 12, 1991
Priority date
Expiry dateMar 19, 2010

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G2215/0643
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

An apparatus which develops an electrostatic latent image. A transport roll advances developer material from a chamber to a donor roll. The donor roll advances the toner particles to the latent image. The latent image attracts toner particles from the donor roll. In order to improve the speed with which toner particles removed from the donor roll are replaced, an alternating voltage is applied between the two rolls. The magnetic transport roll is driven to rotate at a surface velocity at least 2, but not more than 5 times that of the rotational surface velocity of the donor roll. Also, the compression pile height (CPH) vs the spacing between the spacing between the donor roll and the transport roller (DRS) is found to be optimal when meeting the ratio CPH:DRS=2:3.

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