Image sensor with frame level black level calibration
US11206392B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 16, 2020 |
| Grant date | Dec 21, 2021 |
| Priority date | — |
| Expiry date | Jul 16, 2040 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/78
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An image sensor includes a pixel array with active rows of pixel cells, a black level calibration row with black image data generation circuits coupled to generate black image data signals representative of an absence of the incident light, and a dummy row with black level clamping circuits coupled to receive a black sun reference voltage to clamp bitlines of the pixel array, and a black level calibration circuit coupled to receive the black sun reference voltage to generate a black sun calibration voltage. A black sun feedback circuit is coupled to generate the black sun reference voltage in response to the black sun calibration voltage and a black level sample reference, and a black level sampling circuit is coupled to the bitlines to sample the black image data signals to generate the black level sample reference received by the black sun feedback circuit.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.