Digital double sampling in time integrating pixel sensors
US6590610B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2001 |
| Grant date | Jul 8, 2003 |
| Priority date | — |
| Expiry date | Feb 19, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/56
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A double sampling time-integrating pixel sensor having a photo-detector, a capacitor, a comparator and two pixel data buffers. In operation, the photo-current from the photo-detector charges the capacitor and produces a photo-voltage. The photo-voltage sensed by the capacitor and a first reference voltage are compared by the comparator. When the photo-voltage exceeds the first reference voltage, a first global counter value is latched into the first pixel data buffer. When the photo-voltage exceeds a second reference voltage, a second global counter value is latched into the second pixel data buffer. The optical power falling on the photo-detector is determined from the difference between the second and first counter values. An array of sensors is incorporated into a semiconductor device together with circuitry to read and decode the pixel data buffers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.