Optical elements
US4554448A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 25, 1983 |
| Grant date | Nov 19, 1985 |
| Priority date | — |
| Expiry date | Apr 25, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B19/009
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An optical element for location between a source of radiation and a detector (13) includes a first optical surface (10) have a central transmissive area (11) and a surrounding area (12) reflective to radiation from direction of the detector (13). A second optical surface (15) is spaced from the first surface (10) towards the detector (13) and has a central reflective area (16) arranged to reflect radiation passing through area 11 towards the reflective area 12. A transmissive area (18) of the second surface (15) surrounds the central area (16), and is itself surrounded by a reflecting area (17) concentric with the detector (13) and forming a reflective shield for the detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.