Image forming apparatus for controlling the dynamic range of an image
US5293198A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 8, 1991 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Aug 8, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus has a photoconductive element, a developing sleeve, a photosensor and a control device for controlling the dynamic range of an image. A background output VSG is produced from the photosensor when the photoconductive element is rotating and the developing sleeve is rotating and a background output VSG+ is produced from the photosensor when the photoconductive element is rotating and the developing sleeve is not rotating. The control device controls a developing bias, a charge potential, a quantity of exposing light or an amount of toner supply in response to the greater of the two values VSG or VSG+. Also, the gradient of the background output VSG is determined and is used to decide whether the image forming apparatus is in an unusual state or not.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.