Automatic gain control for photosensing devices
US4097732A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1977 |
| Grant date | Jun 27, 1978 |
| Priority date | — |
| Expiry date | Jun 2, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06K2207/1018
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A beam-of-light (BOL) sensor having means for regulating the intensity of the sensor light source to compensate for extraneous factors in its operating environment, e.g., dust accumulation, component aging, misalignment, etc., that may affect consistent sensor operation. The BOL sensor includes a photosensor whose output signal is compared against a reference signal to determine if the light source intensity is of the proper level. The comparison signal is used to gate clock pulses to a counter to adjust its stored count upward or downward, dependent on whether the light source intensity is low or high, respectively. A filter is provided to override interruptions in the photosensor output signal below a predetermined minimum time duration.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.