Photodetectors useful as ambient light sensors having an optical filter rejecting a portion of infrared light
US8492699B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 17, 2010 |
| Grant date | Jul 23, 2013 |
| Priority date | — |
| Expiry date | Sep 11, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/8057
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A photodetector includes one or more first photodiode regions that are covered by an optical filter configured to reject infrared (IR) light and that produce a first current (I1). The photodetector also includes one or more second photodiode regions that are covered by a light blocking material configured to reject visible and infrared light and that produce a second current (I2). The photodetector also includes one or more third photodiode regions that are not covered by the optical filter and are not covered by the light blocking material and that produce a third current (I3). Additionally, the photodetector includes circuitry configured to produce an output indicative of the first current (I1) or a scaled version of the first current (I1), minus the second current (I2) or a scaled version of the second current (I2), minus the third current (I3) or a scaled version of the third current (I3). The optical filter configured to reject IR light can be, e.g., a dielectric reflective optical coating filter, an IR absorption optical coating filter, or a combination thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.