Video signal processor
US6633340B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2000 |
| Grant date | Oct 14, 2003 |
| Priority date | — |
| Expiry date | Dec 28, 2021 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/83
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A video signal processor reduces the deterioration of image quality due to the superposition of noise on a sync signal included in a luminance signal. A frequency discriminator outputs a first error signal if a ratio of the frequency of a frequency-modulated signal during a sync-signal interval to the frequency of a reference frequency signal is smaller than a predetermined ratio. Alternatively, the discriminator outputs a second error signal if the ratio is greater than the predetermined ratio. If the first error signal has been input to a frequency controller a preset number of times or more during an interval before the second error signal is input thereto, the controller instructs a frequency modulator to increase the frequency of the frequency-modulated signal. On the other hand, if the second error signal has been input to the controller a preset number of times or more during an interval before the first error signal is input thereto, the controller instructs the modulator to decrease the frequency of the frequency-modulated signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.