Color imaging apparatus including control system for stabilizing phase and frequency of a video signal carrier frequency
US4857995A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1987 |
| Grant date | Aug 15, 1989 |
| Priority date | — |
| Expiry date | Oct 14, 2007 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/01
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A color filter has a plurality of succesively arranged recurrent groups of different color stripes. An image pickup tube has a photoelectrical conversion target exposed to light passing through the color filter and an index signal generation pattern. The image pickup tube outputs a signal containing a color signal component determined by a carrier which is modulated with the individual color stripes of each recurrent group of the color filter. The output signal from the image pickup tube also contains an index signal component which depends on the index pattern. A first memory holds at least part of the index signal component. The index signal component held by the memory is periodically updated. A second memory holds a portion of the output signal from the image pickup tube which was obtained under conditions where a predetermined color light illuminates the photoelectrical conversion target via the color filter. A reference signal is generated in accordance with the index signal component read from the first memory and with the signal portion read from the second memory. A color signal is detected from the output signal of the image pickup tube by use of the reference signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.