Image sensor with anti-saturation function in pixel level
US7235772B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 2006 |
| Grant date | Jun 26, 2007 |
| Priority date | — |
| Expiry date | Jun 8, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/76
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a CMOS image sensor of the invention, a dynamic range is varied at a per-pixel level by a light amount to prevent saturation without degrading color reproduction of an overall image. A photo diode generates charges in accordance with a received light amount. A drive transistor amplifies the charges generated in the photodiode at a given gain. Further, a saturation detector receives an output voltage from the drive transistor and judges the image sensor saturated if the output voltage is beyond a limited level. A switch switches on/off in response to the judgment of the saturation detector. Also, a plurality of floating diffusions store the charges of the photodiode transferred through the switch. The floating diffusions are selectively connected to both the photodiode and a gate of the drive transistor at on/off the switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.