Liquid crystal display device, method of driving the same, and method of driving a portable information device having the liquid crystal display device

摘要

A liquid crystal display device that displays an image by inputting n (n is a natural number) bit digital signals has n memory circuits in each pixel. The n memory circuits store n bit digital signals, which are converted into corresponding analog signals by a D/A converter provided in each pixel so that the analog signals are inputted to a liquid crystal element. Therefore, when a still image is to be displayed, the stored digital signals are repeatedly used once the digital signals are written in the memory circuits. During the still image is displayed, a source signal line driving circuit and other circuits can stop their driving. Power consumption of the liquid crystal display device thus can be reduced.

主权项

1. A display device comprising:
a plurality of pixels, each of the pixels comprising: an electrode; a storage capacitor electrically connected to the electrode; a liquid crystal element above the electrode; n×m memory circuits, n and m being natural numbers equal to or greater than 2; a source signal line; n gate signal lines; and n thin film transistors, each having a gate electrically connected to a corresponding one of the n gate signal lines, one of a source and a drain electrically connected to the source signal line, and the other of the source and the drain electrically connectable to m of the n×m memory circuits, wherein the n thin film transistors are each electrically connectable to the electrode via a corresponding one of the n×m memory circuits so that the corresponding one of the n×m memory circuits can be connected in series between the electrode and a corresponding one of the n thin film transistors, and wherein the display device is configured so that the n×m memory circuits are each configured to store a corresponding bit of an n-bit digital gray scale signal corresponding to one of m frame periods.