| 摘要 |
<p>PURPOSE: To perform suitable vertical panning, even when a field length is different from a standard. CONSTITUTION: A display means is provided for a video signal, including a vertical synchronized component demarkating an image and forming a field composed of horizontal lines, having a possibility that the number of horizontal lines per field is different from the standard on certain operating condition. Counters 1404 and 1410 and latches 1408 and 1409 measure the number of horizontal line sin the continuous fields. Pan circuit 1416, 1420, 1424 and 1430 generate a vertical reset signal phase-shifted from the vertical synchronized component of video signal just by a certain selected number of horizontal lines and vertically pan the image just by the selected number of horizontal lines on the video display means. The selected number of horizontal lines is adjusted corresponding to the measured length of field, so as to maintain the selected quantity of vertical panning even on certain operating conditions.</p> |
