Patent · US Expired

Brush contact type charging unit in an image forming apparatus

US5012282A · kind A · utility

10Cited by
7References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 11, 1989
Grant dateApr 30, 1991
Priority date
Expiry dateJan 11, 2009

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG03G15/0283
  • WIPO fieldOptics
  • WIPO sectorInstruments

Abstract

A brush type charging unit having a constant-current regulated power supply for supplying a constant current to a moving photosensitive medium through a conductive brush fiber contacting the moving photosensitive medium for charging the photosensitive medium uniformly such that the charged potential varies within a range smaller than 10 V when an atmospheric condition changes from 5.degree. C.-20% RH to 35.degree. C.-80% RH. The constant-current regulated power supply has a pulse removing circuit for charging the moving photosensitive medium uniformly even when a few pin-holes exist in the photosensitive medium. A fiber element has a resistance between 4.5.times.10.sup.7 ohm and 1.times.10.sup.13 ohm when the fiber element has 1 denier in size and 1 mm in length, for charging the photosensitive medium and avoiding burning of the fiber element.

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