Developer device and contra-photography instrument
US5793401A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jul 16, 1996 |
| Grant date | Aug 11, 1998 |
| Priority date | — |
| Expiry date | Jul 16, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2217/0083
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electro-photograph device having two counter-rotating rolls (2, 5). Roll (2) transports a toner layer, controlled by a blade (4), to a printing zone (6). A voltage is applied between rolls (2, 5), in order to transfer low-adhesion toner from roll (2) to roll (5). Consequently, only toner particles having a specified minimum adhesion reach the printing zone (6). Thus, better print quality is obtained and the expenditure for drive electronics is reduced. A multitude of electrodes (18) are located on the side of a paper carrier facing away from the roll (2). A switching device (19) selectively applies the electrodes with a bias with is related to the biases applied to the rolls (2,5).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.