Wavelength encoded optical switches
US4878722A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 1988 |
| Grant date | Nov 7, 1989 |
| Priority date | — |
| Expiry date | Jun 24, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG02B6/3598
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A switch mechanism (11) comprising a red LED light source (13), a filter assembly (15) and a photodetector assembly (17) is disclosed. The photodetector assembly (17) includes two filtered photodetectors (33 and 35) that are aligned with the light source (13) either directly or via a light canal (19). The filtered photodetectors (33 and 35) are designed to detect light in different narrow wavelength bands lying within the band of energy produced by the light source (13). The filter assembly (15) includes a two-position movable element (23) located between the light source (13) and the photodetector assembly (17). The movable element (23) includes two sections (25 and 27) having different light-passing abilities. In one of the movable element positions one section (25) is located between the light source and both filtered photodetectors and in the other movable element position the other section (27) is located therebetween. Preferably, one section (25) is a thin slab of transparent material and the other section (27) is a thin slab of filter material. The transmittance of the filter dye slab (27) is such that the ratio of the energy detected by the filtered photodetectors (33 and 3…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.