Light detection circuit for ambient light and proximity sensor
US7960699B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 22, 2009 |
| Grant date | Jun 14, 2011 |
| Priority date | — |
| Expiry date | Oct 22, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J1/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A circuit for implementing an ambient light sensing mode and a proximity sensing mode includes a first light sensor that is more sensitive to light in the infrared spectrum than to light in the visible spectrum and a light source that emits light in the infrared spectrum. The circuit further includes a second light sensor that is sensitive to light in the visible spectrum and a controller coupled to the first light sensor, the light source, and the second light sensor. The controller is configured to process an ambient light level output from the first light sensor without the light source energized with an output from the first light sensor with the light source energized to implement a proximity sensing mode. Further, the controller is configured to process an output from the second light sensor to implement an ambient light sensing mode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.