Transfer device for use in retention type electrophotographic copying machine
US4401383A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1981 |
| Grant date | Aug 30, 1983 |
| Priority date | — |
| Expiry date | Oct 15, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/1675
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
In a transfer roller for use in a retention type copying machine, a semiconductive transfer roller is connected through a current limiting resistor having a high resistance value of 100 M.OMEGA. to 1000 M.OMEGA. to a transferring bias voltage source. A pair of auxiliary transfer rollers made of conductive material are arranged on respective sides of the transfer roller. The auxiliary transfer rollers are connected to the transferring bias voltage source through a potentiometer. To the transfer roller is applied a first transferring bias voltage of 600 to 900 volts and to the auxiliary transfer rollers is applied a second transferring bias voltage of 400 to 650 volts. When a resistance of a record paper is decreased due to high humidity, the first transferring bias voltage is automatically decreased and the second transferring bias voltage becomes predominant.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.