Image forming apparatus
US7444092B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 27, 2006 |
| Grant date | Oct 28, 2008 |
| Priority date | — |
| Expiry date | Jun 23, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/1614
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus forming a preferable image without white dots caused by excessive charging when a halftone image is formed by providing a potential difference between a surface potential of a photosensitive drum immediately before charging by a charging device, and that of the drum after the charging in an image forming area of the drum. At least one of a charging bias and a transfer bias is changed between a first area and a second area. The first area is an area on the drum that passes a transfer portion when a recording medium is not present between the roller and the drum, and on that a latent image is to be formed. The second area is an area on the drum that passes the transfer portion when the medium is present between the roller and the drum, and on that a latent image is to be formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.