Compact pixel reset circuits using reversed current readout
US7215369B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 2003 |
| Grant date | May 8, 2007 |
| Priority date | — |
| Expiry date | May 12, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/57
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Compact CMOS pixel sensors containing three or four total transistors and four or five control lines provide a high percentage of sensor area for the photodiode that measures light intensity. The CMOS pixel sensors thus have good light sensitivity. The CMOS pixel sensors also provide active reset operations yielding low noise when resetting node voltages. The low transistor count is achieved using the same transistors during both reset operations and readout operation. Reversing the current direction through a pixel sensor during readout allows the row selection transistor to act as a buffer for a transistor having a gate coupled to the photodiode node.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.