Preconditioning media sheets to reduce transfer voltage
US7639979B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2007 |
| Grant date | Dec 29, 2009 |
| Priority date | — |
| Expiry date | Aug 28, 2027 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/1695
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Image transfer quality in an electrophotographic image forming device is improved by preconditioning a media sheet prior to transferring a toner image thereto at an image transfer station. The media sheet is preconditioned by applying a static charge to it. In a color DTM type device, the charge reduces the transfer voltages required at downstream image transfer stations to account for charge accumulated on the media sheet as a result of the image transfer process at upstream image transfer stations. The charge may be applied to the media sheet at a media sheet preconditioning element positioned upstream of an image transfer station. Alternatively, an initial charge may be applied to the media sheet at an image transfer station, without transferring a toner image to the sheet, and returning the sheet via a duplex path to positioned upstream of an image transfer station prior to an image transfer operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.