Electrophotographic copying apparatus having toner image density measuring arrangement for detecting toner concentration
US4962407A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 8, 1988 |
| Grant date | Oct 9, 1990 |
| Priority date | — |
| Expiry date | Apr 8, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/5041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrophotographic copying apparatus includes a photosensitive member, a sensitizing charger, a developing unit for developing the electrostatic latent image by a developer incorporating toner and carrier, and a system for compensating toner concentration and charging potential of the photosensitive member surface. The system forms two reference toner images on the photosensitive member surface under different conditions so as to cause the two reference toner images to have different densities and optically measures the densities of the two reference toner images. Toner concentration in the developer can be detected based on the two reference toner image densities. When the toner concentration is less than a specified value, toner is supplied to the developer. Further, the charging potential of the photosensitive member surface is determined based on the toner concentration and the density of the reference toner image formed under the normal image formation condition, and may be corrected in accordance with the determined potential.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.