Image forming apparatus
US5253022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 15, 1990 |
| Grant date | Oct 12, 1993 |
| Priority date | — |
| Expiry date | May 15, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/1652
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An image forming apparatus includes a movable image bearing member; an image forming device for forming a toner image on the image bearing member; an image transfer device for transferring the toner image onto a transfer material at a transfer position, the transfer device including a rotatable member contactable to such a side of the transfer material as is opposite from a side contactable to the image bearing member and an electric field forming device for forming an electric field between the image bearing member and the rotatable member; wherein the electric field forming device forms a first electric field effective to transfer the toner from the rotatable member to the image bearing member and a second electric field which is opposite in a direction from the first electric field during a period in which the transfer material is absent at the transfer position, wherein each of the first and second electric fields is formed at least for a period required for the entire surface of the rotatable member passes through the transfer position.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.