Document imaging system using a three-dimensional relative illumination corrector
US4653901A · kind A · utility
2Cited by
10References
7Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 18, 1986 |
| Grant date | Mar 31, 1987 |
| Priority date | — |
| Expiry date | Apr 18, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03B27/542
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A three-dimensional, relative illumination corrector is positioned in a document imaging system so as to compensate for the cos 4 illumination falloff effect at the center field angles. The corrector is positioned at either the image or the object side of the system projection lens. In a first embodiment, the corrector is a generally conical, solid body. In a second embodiment, the corrector interior is hollow to permit a higher level of on-axis illumination.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.