Light beam receiver with interference signal suppression
US7838813B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 31, 2008 |
| Grant date | Nov 23, 2010 |
| Priority date | — |
| Expiry date | May 30, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/4257
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved laser light beam receiver rejects unwanted pulses of optical energy, such as strobe lights or other flashes of light, that can occur on a jobsite. The receiver analyzes a light beam reception by using a photosensitive light beam detector arrangement and a separate photoelectric detector serving as an interference signal detector. This additional detector is not easily able to detect the light beams needed in normal operation. On the other hand, the additional detector does detect mostly all interfering light flashes—caused by flash lamps and other similar devices—whose threshold limit is either at the same level or below that of the light beam detector arrangement. An evaluating circuit such as a microcontroller correlates the time of reception of the light beam detector arrangement and the interference signal detector in order to discard the result if the times of reception correspond to a major extent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.