Optical distance measurement apparatus and method using cleaning device
US5623334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 29, 1994 |
| Grant date | Apr 22, 1997 |
| Priority date | — |
| Expiry date | Dec 29, 2014 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/931
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Optical distance measurement apparatus and method. The apparatus comprises a light emitting circuit, a light receiving circuit, a trigger signal generation circuit, a pollution sensor, a diode abnormal state sensor, a control/time-distance conversion circuit, a cleaning device and a car collision prevention device. The pollution sensor receives a part of a light beam which is emitted from the light emitting circuit and then reflected from protecting glass mounted on a front side of the apparatus, to sense a variation in a reflectivity of the protecting glass, and discriminates a polluted state of the protecting glass in accordance with the sensed result. The diode abnormal state sensor receives the part of the light beam which is emitted from the light emitting circuit and then reflected from the protecting glass, to sense an abnormal state of a light emitting laser diode in the light emitting circuit, and emits a light beam to the light receiving circuit through the protecting glass to sense an abnormal state of a light receiving photo diode in the light receiving circuit. The cleaning device removes pollution on a front surface of the protecting glass under control of the control…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.