Self-mixing laser range sensor
US7283214B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 2005 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Oct 25, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01S5/183
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A laser range finder includes a laser and a photosensitive element. The laser projects a beam onto a target surface. A backscattered portion of the laser beam returns to the laser from the target surface and enters the laser emitting cavity. Variations in laser output power are detected by the photosensitive element, which provides a “beat” signal to a frequency detection circuit. The frequency detection circuit includes a difference frequency analog phase locked loop (DFAPLL) providing a purified form of the beat signal. The frequency of the purified beat signal is determined and used to calculate distance to the target surface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.