High-speed sampling of signals in active pixel sensors
US7630011B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 17, 2000 |
| Grant date | Dec 8, 2009 |
| Priority date | — |
| Expiry date | Mar 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/616
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Techniques are disclosed for enhancing the speed at which pixel levels are read out and sampled for processing. A method of processing pixel levels includes clamping a pixel readout line to a voltage level less than a voltage corresponding to a signal sensed by an n-MOS pixel. Subsequently, the pixel readout line is coupled to an output of an n-MOS source-follower and the pixel signal is read out onto the pixel readout line through the n-MOS source-follower. The pixel signal that was read out is passed through a p-MOS source-follower to a processing circuit. Before passing the pixel signal through the p-MOS source-follower to the processing circuit, a capacitive storage node in the processing circuit is clamped to a voltage greater than a signal at an input to the p-MOS source-follower. Subsequently, an output of the p-MOS source-follower is coupled to the processing circuit, and a signal corresponding to the pixel signal is stored by the processing circuit. Similar techniques are provided for reading out and sampling p-MOS pixels.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.