Device for separating synchronous signal and method thereof
US8199254B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 30, 2007 |
| Grant date | Jun 12, 2012 |
| Priority date | — |
| Expiry date | Apr 12, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/08
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In a device for separating a synchronous signal in a video signal, a capacitor receives the video signal to obtain a coupling signal, a level determining circuit receives the coupling signal and compares a voltage level of the coupling signal with a number of reference voltages. The reference voltages define several reference voltage ranges, one of which is a predetermined reference voltage range. The level determining circuit outputs an adjusting signal according to a reference voltage range corresponding to a minimum voltage level of the coupling signal within a predetermined time period. A level adjusting circuit has several current sources for receiving the adjusting signal and thus controls the current sources to adjust a DC level of the coupling signal. A synchronous signal separating circuit separates the synchronous signal from the coupling signal when the minimum voltage level of the coupling signal is substantially within the predetermined reference voltage range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.