Low noise photoelectric detector apparatus
US3996476A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 10, 1975 |
| Grant date | Dec 7, 1976 |
| Priority date | — |
| Expiry date | Sep 10, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/04
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photoelectric sensor includes a photodetector, a lens, and a light source all mounted within a framework for holding the lens with the photodetector and light source located on the central axis of the lens. The photodetector is positioned on the rear side of the lens within the framework at approximately the lens focal point. The light source is positioned to emit light away from the front side of the lens. Structure in the form of an opaque collar is provided for mounting the light source relative to the lens to prevent impingement of spurious light from the light source upon the lens. An object positioned in front of the lens intercepts the emitted light from the light source and reflects it back toward the lens, whereupon it is directed to the photodetector. A signal indicative of the presence of the object is provided by the photodetector responsive to the reflected light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.