Liquid crystal display device capable of selecting display definition

Abstract

An input analog image signal is sampled by first and second A/D converters, using first and second sampling clocks of the same period, to obtain digital gradation data. In the case of a double definition display mode, the first and second sampling clocks are made 180.degree. out of phase with each other and the output of the first A/D converter is delayed for one-half period, by which its timing is brought into agreement with that of the output of the second A/D converter, thus obtaining a pair of digital gradation data. In the case of a standard definition display mode, the first and second sampling clocks of the same phase are used to obtain the outputs of the first and second A/D converters as a pair of digital gradation data. The pair of digital gradation data Da and Db is converted by a signal processing part into a pair of analog gradation data Aa and Ab, which is subjected to a serial-to-parallel conversion by a source driver to be supplied in parallel to data lines. In the double definition display mode the gate driver sequentially drives odd-numbered row lines in odd-numbered frames and even-numbered row lines in even-numbered frames. In the standard definition display mode every two adjacent row lines are simultaneously driven in a sequential order.