Developing device and multi-color recording apparatus
US4947200A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | May 17, 1989 |
| Grant date | Aug 7, 1990 |
| Priority date | — |
| Expiry date | May 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/09
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device is of non-contact development type in which a toner is jumped to a photoconductor to develop a latent image on the photoconductor. The developing device is controlled in height of a developer-agent layer on a developer roll, and sets a developing gap between the photoconductor and the developer roll in such a manner that a driving electric field required for jumping of the toner can be maintained at the air gap between the photoconductor and a developer-agent layer on the developer roll and developing bias voltage can be brought to a value lower than charged electric potential of the photo-conductor. By setting the developing bias voltage to the valve lower than the charged electric potential of the photoconductor, jumping of additional or unnecessary toner is restricted so that contamination of an image and a recording sheet can be prevented. Further, a multi-color recording apparatus having this developing device prevents toner developer agents different in color from being brought into contact with each other to form a clear multi-color image without mixing in color and contamination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.