Black level background compensation for target integrating television systems
US5001565A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 30, 1990 |
| Grant date | Mar 19, 1991 |
| Priority date | — |
| Expiry date | May 30, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N23/81
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system and method of automatically deriving and using a black level control signal for use in long term target integrating camera systems is disclosed. The method employs the steps of, sequentially, first operating the camera in a long term target integration manner at a pre-selected exposure time and detecting and holding the inverse peak level of the television video signal derived from this scan taken from the central portion of the target, generating a corrective signal from the held inverse peak level and applying that corrective signal to the camera while operating the camera for long term target integration periods in essentially the same manner and exposure time to produce a corrected television scan signal, and using that corrected signal to reproduce an image. A television camera system is disclosed for automatically implementing this process, which system includes a vertical interval control circuit responsive to a time selector and start input to generate the control signals to the camera for gating off the scan, a first scan signal, gating signals (using flip-flops driven from the horizontal and vertical scan signals) and gates to feed only the video signals from the…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.