Image density control method for an image forming apparatus
US5028960A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 10, 1990 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Apr 10, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image density control method for an image forming apparatus of the type forming a latent image of a document image on a photoconductive element and developing the latent image to form a toner image by an electrophotographic procedure. A background pattern is implemented as a light pattern having a low density and provided independently of a reference density pattern. The light pattern is illuminated to form a latent image thereof on the photoconductive element, and the latent image is developed by a toner. The density of the resultant toner image is sensed by an image density sensor. Such a procedure allows a change in background density ascribable to contamination, increase in background potential and so forth to be detected. The light pattern may be replaced with a leading edge portion of a document if the leading edge portion has a density corresponding to the background density. Then, the latent image of the background pattern will be formed under exactly the same conditions as the latent image of an ordinary image, i.e., without any limitations as to the position of the pattern.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.