CMOS image sensor and method for operating a CMOS image sensor in a weak inversion mode with increased dynamic range
US7349018B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2002 |
| Grant date | Mar 25, 2008 |
| Priority date | — |
| Expiry date | Jan 27, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/803
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
There is disclosed a CMOS technology image sensor and a method for operating such an image sensor. This sensor includes a plurality of pixels (50) each including a photo-sensor element (PD) producing charge carriers in proportion to its illumination and storage means (C1) capable of being coupled and uncoupled from the photo-sensor element at a determined instant in order to store, on a memory node (B) of the pixel, a measuring signal representative of the charge carriers produced by said photo-sensor element during an exposure phase.Each pixel includes at least one MOS transistor (M1; M3) connected in series via its drain or source terminals to the photo-sensor element, and the transistor is configured such that it operates at least partially in weak inversion so that, during the exposure phase, the pixel has a logarithmic response for illumination levels higher than a determined illumination level.This at least partially logarithmic response enables the pixel dynamic range to be increased.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.