Measurement system incorporating ambient light component nullification
US9880266B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 31, 2015 |
| Grant date | Jan 30, 2018 |
| Priority date | — |
| Expiry date | Oct 15, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S17/08
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An optical measurement system includes a photodetector coupled in series with a field effect transistor (FET) that is a part of a sample and hold circuit. When the sample and hold circuit is in a sampling mode of operation, a voltage bias is applied to the FET and the photodetector is exposed to ambient light, thus resulting in a first current flow through the photodetector. One of several components can be selected in the sample and hold circuit for obtaining a desired time constant. When the sample and hold circuit is subsequently placed in a hold mode of operation, a second current flows through the photodetector due to exposing of the photodetector to a combination of ambient light and light associated with an optical measurement. A portion of the second current that is attributable to the light associated with the optical measurement is used for executing the optical measurement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.