Calibration in multiple slope column parallel analog-to-digital conversion for image sensors
US8994832B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2014 |
| Grant date | Mar 31, 2015 |
| Priority date | — |
| Expiry date | Dec 17, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/77
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An apparatus includes analog-to-digital (A/D) conversion circuitry coupled to a pixel array. The A/D conversion circuitry includes a voltage ramp generator and a set of column A/D conversion circuits. The voltage ramp generator generates a single slope voltage ramp in a first state and a multiple slope voltage ramp in a second state. The set of column A/D conversion circuits is coupled with the voltage ramp generator. The apparatus further includes calibration circuitry coupled with the set of column A/D conversion circuits and operable to determine digital calibration data to adjust digital image data. The calibration circuitry provides analog calibration data that spans a calibration range to the set of column A/D conversion circuits instead of the analog image data from the pixel array being provided to the set of column A/D conversion circuits.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.