Patent ID: 7502076

Claim:
A digital display device constructed to receive an analog signal representing an image formed of pixels in video lines, the video lines including an active video region, and to receive a signal containing a synchronization waveform for the image, comprising: an analog-to-digital converter to receive the analog signal and convert it into a sampled digital waveform for displaying the image; a phase-locked loop including a programmable frequency divider, wherein the programmable frequency divider is controlled by a dividing ratio, and wherein the phase-locked loop is coupled to the signal containing the synchronization waveform and is coupled to the analog-to-digital converter to control its sampling time; and a dividing-ratio circuit coupled to the programmable frequency divider to control the dividing ratio for the programmable frequency divider; wherein the dividing ratio is computed by: selecting a dividing ratio; measuring the number of pixels in a video line using the dividing ratio to control the programmable frequency divider; and recomputing the dividing ratio by multiplying the dividing ratio by the expected number of pixels in a video line and dividing by the measured the number of pixels in a video line.