Method and apparatus for forming a positive electrostatic image
US4014694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1975 |
| Grant date | Mar 29, 1977 |
| Priority date | — |
| Expiry date | Feb 18, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/346
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A machine for making a copy on a medium such as paper of a visual image. Particles of toner material are accelerated toward the paper through an apertured screen. Formed on the screen is a pattern of electrostatic charge regions that corresponds to the image so that the arrangement of the toner particles impinging on the paper corresponds to the image. A composite apertured screen composed of two conductive layers separated by an insulative layer and having an insulative layer on one outer surface. Means for establishing oppositely polarized fields across the inner insulative layer and across the outer insulative layer. One of the fields is selectively discharged to control the passage of toner particles through the apertures in the screen.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.