Exposure control and other component control for electrostatic copying machine
US4306804A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 6, 1979 |
| Grant date | Dec 22, 1981 |
| Priority date | — |
| Expiry date | Aug 6, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S222/01
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure unit radiates a light image of an original document onto a charged photoconductive member to form an electrostatic image through localized photoconduction. A developing unit applies a powdered developing substance comprising carrier particles and toner particles to the photoconductive member to develop the electrostatic image and produce a toner image which is transferred and fixed to a copy sheet to produce a permanent reproduction of the original document. Prior to exposure with the light image a reference electrostatic image is formed on the photoconductive member and the electrostatic potential thereof is measured. The intensity of the light image of the original document and/or a developing bias voltage are regulated in accordance with the sensed electrostatic potential. The reference image may be of a reference surface having a predetermined optical density or a portion of the original document produced by reverse optical scanning.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.