Imaging sensors
US9313428B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2014 |
| Grant date | Apr 12, 2016 |
| Priority date | — |
| Expiry date | Dec 17, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/771
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Described herein is a pixel readout circuit which provides readout at two sensitivity levels depending on the amount of electrons generated by a pixel photodiode in the circuit. A floating diffusion capacitor operates to store charge up to a saturation value determined by its capacitance and an overflow capacitor is provided in an overflow region for storing charge above the saturation value of the floating diffusion capacitor. Readout at a high sensitivity level is provided when the floating diffusion capacitor is not saturated and readout at a lower sensitivity level is provided when there is saturation and subsequent overflow to the overflow region. Connection of the floating diffusion capacitor to the overflow capacitor shares the charge over the combined capacitance of the two capacitors and provides readout at a lower sensitivity without loss of charge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.