Developing device for an image forming apparatus
US5486909A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 11, 1995 |
| Grant date | Jan 23, 1996 |
| Priority date | — |
| Expiry date | May 11, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0921
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device for an image forming apparatus and having a relatively hard first developing roller formed with fine N-S magnetic poles on the periphery thereof, and a relatively soft second developing roller for conveying toner electrostatically transferred thereto from the first roller toward a photoconductive drum. The toner is charged by friction while being passed through between the first roller and a blade, and then magnetically deposited on the first roller. At a position where the first and second rollers contact each other, the adequately charged toner is substantially evenly charged by friction and electrostatically transferred from the first roller to the second roller. The second roller conveys the toner toward the drum. The second roller has a surface roughness whose ratio to the mean particle size of the toner is selected to be less than or equal to 1.5.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.