Gray scale monocomponent nonmagnetic development system
US5255057A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 29, 1992 |
| Grant date | Oct 19, 1993 |
| Priority date | — |
| Expiry date | May 29, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/0808
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrostatic latent image on a photoconductor of an electrophotographic device is developed by a gray scale monocomponent nonmagnetic development system using a combination of AC and DC bias voltages applied to a developer roller and a monocomponent nonmagnetic developer applied to the developer roller by an adder roller. The developer comprises a mixture of toner particles charged to one polarity and transparent beads charged to the opposite polarity, by triboelectric charging in bulk in an alternating field between the two rollers, rather than by friction contact with apparatus surfaces. The adder roller applies the charged mixture to the developer roller for developing the latent image in an electric field to an image density determined by the magnitude of the DC bias. A DC bias may be applied to the adder roller, especially to provide a gradient relative to the DC component of the developer roller bias for driving the bulk charged mixture onto the developer roller. A doctor blade is usable to smooth the toner into a selective thickness layer on the developer roller. The developer roller may have an uncoated semiconductive surface layer, or one covered by a non-conductive co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.