DEVICE AND METHOD FOR CONVERTING VIDEO SIGNAL, IMAGE DISPLAY DEVICE USING IT AND TELEVISION RECEIVER

摘要

PROBLEM TO BE SOLVED: To obtain a video signal with high image quality in the case that number of lines in a vertical direction or number of pixels in a horizontal direction is converted into a number in excess of, a multiple, e.g. twice. SOLUTION: A signal of each field of an NTSC system video signal SNT whose line number is 252.5 (a valid line number is 240) is converted into a signal of each frame of a video signal SXG corresponding to an extended graphic array XGA whose line number is 840 (a valid line number is 768). A video signal converter 13 consists of an image adaptive double speed conversion circuit 100 that converts the video signal SNT into a video signal S2N of the interlace scanning system whose number of lines is twice and of an interpolation circuit 180 that converts the video signal S2N into a video signal SXG. The quality of the video signal S2N obtained by conversion processing of a video adaptive type is high. Deterioration in image quality of the video signal SXG obtained from the video signal S2N through interpolation processing is less than the image quality obtained from the video signal SNT only through the interpolation processing and then a video signal with high image quality is obtained.