Black and white reference and end-of-scan indicator for charge coupled devices
US4675549A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 3, 1985 |
| Grant date | Jun 23, 1987 |
| Priority date | — |
| Expiry date | Apr 3, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N25/701
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Structure is disclosed for a charge-coupled device for generating reference signals indicative of black and white optical conditions and for generating an end-of-scan indicator signal. The black reference signal is generated by electrically and optically isolating one or more photosites of the CCD. A white reference signal is generated by injecting a controlled amount of charge into one or more elements of a shift register of a charge-coupled device. The end-of-scan indicator signal is generated by injecting a signal into at least one element of a shift register which does not have photosites associated with it. The black and white reference signals allow the utilization of the full dynamic range of the device under a wide range of operation conditions, while the end-of-scan indicator eliminates the need for external counting or reset circuits associated with conventional charge-coupled devices.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.