Clamping device and clamping method
US6700609B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 17, 2000 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Jul 17, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/633
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An optical black portion in an output of a CCD image pickup device is extracted and a clamp level of each line is obtained by an integrating and averaging circuit. A difference value of the clamp levels between the front and rear lines and an absolute value of the difference are calculated by a comparing circuit. Either the clamp level of each line or the clamp level updated every (+1) or (−1) is selected by a selector in accordance with whether the absolute value of the difference of the clamp levels between the front and rear lines lies within a predetermined range or not. The clamp level which is outputted from the selector is subtracted from the output of the CCD image pickup device.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.