Video camera, printer apparatus and method of controlling same, and apparatus and method for detecting print inhibit signal
US5877810A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1996 |
| Grant date | Mar 2, 1999 |
| Priority date | — |
| Expiry date | Dec 30, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N2201/3287
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The levels of video signals obtained by photography at a relatively high shutter speed and photography at an ordinary shutter speed are made approximately equal at all times, irrespective of any change in the characteristics of an AGC. Photography performed at a relatively high shutter speed of one time in a plurality of fields and photography is performed at an ordinary speed at other times is repeated periodically. One field of a luminance signal obtained by photography at the relatively high shutter speed is integrated by a first integrating circuit, and one field of the luminance signal obtained by photography at the ordinary shutter speed is integrated by a second integrating circuit, wherein the luminance signals represent contiguous images. A signal representing the difference between these integrated values is produced by a difference detecting circuit. The difference signal serves as a gain correction signal. The gain correction signal is added to a gain control signal, and the resulting signal is applied to the AGC. The gain control signal of the AGC is corrected by the gain correction signal so that the average level of the video signal resulting from photography at the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.