Liquid crystal display device and driving method thereof

Abstract

On an interface of a liquid crystal display device, which converts the number of pixels of image signals inputted from an external signal source, such as a host computer, into image signals having a smaller number of pixels and fetches the image signs into drain drivers at double edges of a clock signal of low frequency, a clock surveillance unit is mounted, which includes a clock synthesizer and a clock comparator circuit, and which detects the presence or the absence of an irregularity in the timing of a pixel clock signal inputted from the external signal source and outputs a determination of the normal/irregular status of the pixel clock signal. When it is determined that the pixel clock signal is irregular, the supply of image data to the drain drivers from a parallel-serial converter is stopped, so that the generation of an irregularity in the display produced by the liquid crystal display device can be obviated.