Display filter arrangements
US5268788A · kind A · utility
63Cited by
4References
3Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jun 12, 1992 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | Jun 12, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B27/281
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A display especially for viewing by a night-vision aid has an array of LED's which emit green light. A dichroic filter is located in front of the display and transmits radiation at the peak emission of the diodes but reflects radiation in the range to which the night-vision aid is sensitive. A bandpass filter located in front of the dichroic filter prevents transmission of longer wavelengths, and a circularly polarizing filter in front of the bandpass filter prevents transmission of radiation reflected specularly from surfaces behind it.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.