Optical sensor
US4955238A · kind A · utility
3Cited by
19References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 21, 1989 |
| Grant date | Sep 11, 1990 |
| Priority date | — |
| Expiry date | Feb 21, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/305
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical sensor uses a torsion-mounted thin silicon paddle (1) with magnetically soft material on its back. A light beam falls on the front face and part of the beam is reflected to a photo-diode (4) whose output drives a current in a magnetizing coil (5). The magnetic field thus produced rotates the paddle out of the beam, which cuts off the light to the photo-diode. Thus the paddle oscillates with an amplitude which depends on the strain due to the torsion mounting. This modulates the light beam, and if they have different resonances several such sensors can share the same beam with a common read-out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.