Unit pixel of CMOS image sensor
US7348533B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 17, 2006 |
| Grant date | Mar 25, 2008 |
| Priority date | — |
| Expiry date | Jul 17, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/671
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a unit pixel of a CMOS image sensor which compensates for a dark current generated in a photo diode to enhance its driving range, the photo diode generates a charge in accordance with a received light amount. A drive transistor has a gate for receiving the charge in the photo diode to output as an electrical signal, and a drain to which a power voltage is applied. A saturation detector receives a gate voltage of the drive transistor and judges the drive transistor saturated if an output voltage is smaller than a preset reference voltage. A switch connects or disconnects between the power voltage and the gate of the drive transistor in response to the judgment of the saturation detector.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.