Photo-electric smoke detector with light shielding electrode
US4678921A · kind A · utility
12Cited by
2References
8Claims
0Family size
Assignees
Inventors
Key dates
| Filing date | Feb 11, 1985 |
| Grant date | Jul 7, 1987 |
| Priority date | — |
| Expiry date | Feb 11, 2005 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2201/062
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a photo-electric smoke detector device, a first photo-detector receives the light emitted from a light emitter and scattered by smoke, and a second photo-detector directly receives the light emitted from the light emitter. The second photo-detector has an element surface on which trimmed electrodes are arranged. The electrodes of the second detector act to limit the amount of light emitted from the light emitter and transmitted to the elements of the second detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.