Method and apparatus for analog graphics sample clock frequency verification
US7733424B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 16, 2006 |
| Grant date | Jun 8, 2010 |
| Priority date | — |
| Expiry date | Mar 11, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/12
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for an analog-to-digital video signal converter. The converter is controlled by a clock with controllable frequency and phase for sampling an analog signal. A measure of the difference between successive frames of the image is computed for a sequence of clock phases. The measure can be a count taken over pixels of the magnitude of the difference between a pixel in one frame and the corresponding pixel in a following frame exceeding a threshold value. The frequency of the clock is verified using a characteristic of the frame difference. The characteristic can be the ratio of the maximum measure to the minimum measure over the selected clock phases. Other characteristics can be used such as a difference of a maximum and a minimum measure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.