Liquid crystal display device realizing a small size by reducing number on input/output terminals

A liquid crystal display device comprising a liquid crystal panel and a scan electrode drive circuit and signal electrode drive circuit which drive the liquid crystal panel in accordance with signals from a controller, said scan electrode drive circuit and said signal electrode drive circuit each settable to at least two operating states, wherein a means of detecting the mutual phase lead/lag relationship of two arbitrary signals which differ in phase is provided within said scan electrode drive circuit or signal electrode drive circuit, said operating states of either said scan electrode drive circuit or said signal electrode drive circuit being set as a result of detecting the mutual phase relationship of said two arbitrary signals which differ in phase;

• wherein said means of detecting the phase lead/lag relationship between said two arbitrary signals which differ in phase is provided with a D-type flip-flop, one of two said arbitrary signals being connected to the data input of said D-type flip-flop, and the other of two said signals being connected to the clock input of said D-type flip-flop, and whereby the data input signal is latched on either the rising edge or the falling edge of the clock input, and output at the Q the output of said D-type flip-flop is a signal which indicates the phase lead/lag relationship.