Device for ambient light compensation for optical sensors exposed to both useful light and ambient light
US8822901B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2012 |
| Grant date | Sep 2, 2014 |
| Priority date | — |
| Expiry date | Jul 12, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/4228
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The device for ambient light compensation for use in optical sensors exposed to both useful light and ambient light comprises at least one first photodiode and at least one second photodiode, the at least one first photodiode being adapted to be exposed to substantially the same useful light and ambient light as the at least one second photodiode. The device further comprises a current mirror circuit having an input and an output, the at least one first photodiode being connected to the input of the current mirror circuit, and the at least one second photodiode being connected to the output of the current mirror circuit. The current mirror circuit comprises a lowpass filter connected between the input and the output of the current mirror circuit. The output of the current mirror circuit provides an output signal representing the useful signal compensated for ambient light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.