Test patch generation utilizing system scan optics
US4618248A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 18, 1985 |
| Grant date | Oct 21, 1986 |
| Priority date | — |
| Expiry date | Mar 18, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G2215/00042
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrophotographic printing machine utilizing an optical illumination and scanning system which, besides performing the conventional document reproducing function, is adapted to operate in a machine test mode. In the test mode, target strips of varying density affixed to the bottom of a platen are projected as test patch images onto the surface of a photoreceptor. The voltage levels of these patches are then measured and used to adjust variable parameters to maintain optimum operation. The optical system, when operating in the test mode, sequentially and selectively illuminates various of the test patches while control means selectively varies the illumination levels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.