Variable background intensity apparatus for imaging systems
US4062619A · kind A · utility
24Cited by
3References
18Claims
0Family size
Inventor
Key dates
| Filing date | Mar 25, 1975 |
| Grant date | Dec 13, 1977 |
| Priority date | — |
| Expiry date | Mar 25, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B21/24
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A variable background intensity control system employs a modulator plate having different density or transmittance regions located thereon. The modulator contains an area upon which an aperture slit or image is normally registered. By varying the position of this image on the plate, one can achieve a change in background intensity. Other embodiments show the use of additional aperture images registering on other regions of the modulator to achieve background or contrast variations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.