Single-exposure high dynamic range CMOS image sensor pixel with internal charge amplifier
US9729808B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2015 |
| Grant date | Aug 8, 2017 |
| Priority date | — |
| Expiry date | Feb 12, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10F39/8037
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A single-exposure high dynamic range (HDR) image sensor utilizes a charge amplifier having a selectively coupled conversion capacitor to read a single photodiode charge during a multi-phase readout operation. An overflow readout is performed during the photodiode charge integration phase, and utilizes the conversion capacitor to read overflow signals indicating rapidly rising photodiode charges caused by extreme exposure conditions, which also prevents saturation of the photodiode. At the end of the integration phase, the remaining photodiode charge is then measured using two readouts: a high sensitivity readout during which the storage capacitor de-coupled to accurately measure low-light conditions, and a low sensitivity readout during which the remaining photodiode charge is stored on the storage capacitor to provide normal light image data. Final single exposure HDR image data is then calculated by summing the overflow image data with the high-sensitivity and/or the low-sensitivity image data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.