Optical projection system
US4474459A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 19, 1983 |
| Grant date | Oct 2, 1984 |
| Priority date | — |
| Expiry date | Jan 19, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G15/041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical projection system of unit magnification for transmitting a real erect image of an object from an object plane to an image plane, comprises a plurality of lenses having parallel optical axes and being arranged in one or more rows. Each lens comprises three or four lens elements arranged along a common optical path extending between the object and image planes, and includes at least two aperture masks which subtend light rays from the axial and off-axis object points in the object plane. These aperture masks are arranged in positions where the image-forming pencil of light rays passing through the lens has a relatively large cross-section.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.