Condensers for illumination systems
US5515123A · kind A · utility
3Cited by
10References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 17, 1994 |
| Grant date | May 7, 1996 |
| Priority date | — |
| Expiry date | Feb 17, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B19/0047
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A condenser lens for a projection system optimizes the amount of overall brightness directed toward an aperture and the uniformity of illumination at the aperture. The lens, when placed in the projection system, has a marginal ray which starts at the center of the light source, passes through the edge of the condenser lens, and intersects the region to be illuminated at or near its edge. The lens further has a relative zonal ray height which is selected based on the distance from the light source to the aperture. The condensing lens system is particularly useful in the construction of overhead projectors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.