Developing device with a developer carrier capable of forming numerous microfields thereon
US5339141A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 1993 |
| Grant date | Aug 16, 1994 |
| Priority date | — |
| Expiry date | Feb 16, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0818
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A developing device applicable to an electrophotographic copier, facsimile transceiver, laser printer or similar image forming apparatus and having a developing roller for carrying a nonmagnetic single component type developer, i.e., a toner and a toner supply roller for supplying the toner to the developing roller. The developing roller has dielectric portions and conductive portions each having a small area and distributed together on the surface thereof. The conductive portions are connected to ground and have a volume resistivity of 10.sup.6 .OMEGA.cm or below. The toner supply roller is made up of a metallic core and an elastic foam layer provided on the core and having conductivity and a predetermined frictional charging characteristic. A potential difference is set up between the developing roller and the toner supply roller to generate electric fields which act on a frictionally charged toner as a force directed from the toner supply roller toward the developing roller. Micropores existing in the surface of the toner supply roller have a depth and a size selected in such a manner as not to disturb microfields formed by frictional charges deposited on the dielectric portions…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.