Television video signal A/D converter

摘要

A television video signal A/D converter apparatus has an A/D converter which samples a television video signal to A/D convert it in accordance with upper and lower reference potentials, and supplies the digital signals to a liquid crystal display device. The apparatus also has detectors which detect digital values of the digital signals from the A/D converter which exceed a predetermined value and are below another predetermined value, and which respectively correspond to the upper and lower reference potentials for A/D conversion by the A/D converter. The digital values exceeding and below the predetermined values are counted by a counter, and the upper and lower reference potentials are determined in accordance with the respective counts and are supplied to the A/D converter.