Single-exposure high dynamic range CMOS image sensor pixel with internal charge amplifier
US9106851B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 12, 2013 |
| Grant date | Aug 11, 2015 |
| Priority date | — |
| Expiry date | Feb 6, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/77
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A single-exposure high dynamic range (HDR) image sensor utilizes a charge amplifier having two different charge-to-voltage conversion capacitors that read a single photodiode charge during a two-phase readout operation. The first capacitor has a lower capacitance and therefore higher conversion gain (sensitivity), and the second capacitor has a higher capacitance and therefore lower conversion gain (sensitivity). The two-phase readout operation samples the photodiode charge twice, once using the high sensitivity capacitor and once using the low sensitivity capacitor. The high sensitivity readout phase provides detailed low light condition data but is saturated under brighter light conditions, and the low sensitivity readout phase provides weak data under low light conditions but provides high quality image data under brighter light conditions. The final HDR image is created by combining both high and low sensitivity images into a single image while giving each of them the correct weighted value.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.