Control method for an active pixel image sensor
US10798323B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 13, 2017 |
| Grant date | Oct 6, 2020 |
| Priority date | — |
| Expiry date | Dec 12, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/771
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In an active pixel sensor comprising a photodiode Dp, a memory node MN and a readout node SN, the memory node being provided to contain the charge generated by the photodiode at the end of an integration period allowing an integration in global shutter mode and a correlated double sampling, it is envisaged to carry out, in each integration period, at least one transfer {circle around (2)} of charge from the photodiode to the memory node followed by clipping {circle around (3)} of the amount of charge contained in the memory node at an intermediate voltage t1 after the start of the integration period but before a last transfer of charge {circle around (4)} to the memory node at the end of the integration period. The pixels are subsequently read out, row by row, by correlated double sampling CDS. The one or more intermediate transfers, with clipping, to the memory node during the integration period allow the dynamic range of the sensor to be extended to high levels of ambient light while retaining good sensitivity to low levels of ambient light.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.