Transfer roller with voltage polarity control
US5182604A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 15, 1991 |
| Grant date | Jan 26, 1993 |
| Priority date | — |
| Expiry date | Mar 15, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/169
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus includes an image bearing member movable along an endless path, an image forming system for forming a toner image on the image bearing member, and a transfer device for transferring the toner image from the image bearing member to a transfer material at a transfer position. The image forming system includes a charger for charging the image bearing member, and a developer. The transfer device includes a transfer member contactable to a backside of the transfer material. The transfer member is supplied with a voltage having a polarity which is the same as the charging polarity of the toner during a developing operation to transfer the toner from the transfer member to the image bearing member when the transfer material is absent at the transfer position. Also provided is a device for causing a region of the image bearing member to have a potential of the same polarity as the charging polarity of the charger before the region is charged by the charger for image formation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.