Video signal converter, conversion method of video signal, image display unit using them and television receiver

摘要

This invention relates to a video signal converter, a conversion method of video signal, respectively suitable to be applied when a video signal according to National Television System Committee (NTSC) is illustratively converted to a video signal corresponding to an extended graphics array (XGA), an image display unit using the converter and conversion method, and a television receiver. A signal in each field of a video signal SNT according to NTSC in which the number of lines is 252.5 (effective line number is 240) is converted to a signal in each frame of a video signal SXG corresponding to XGA in which the number of lines is 840 (effective line number is 768). A video signal converter is composed of an image adaptive double-speed conversion circuit for converting a video signal SNT to a video signal S2N according to an interlaced scanning method in which the number of lines is doubled and an interpolation circuit for converting the video signal S2N to a video signal SXG. A video signal S2N acquired by image adaptive conversion processing is a video signal of high image quality. A video signal SXG acquired by interpolation processing based upon the video signal S2N is a video signal of high image quality free of the deterioration of the quality of an image, compared with a video signal SXG acquired only by interpolation processing based upon a video signal SNT.