A method to obtain grey scales and higher frame speed in liquid crystal displays, having steep slope of the electrooptical characteristic

摘要

Liquid crystal displays like supertwisted type, having a very steep slope of the electrooptical curve, or even bistability, are distinguished by high contrast and allow also to realize high numbers of addressable rows, means they offer higher information content. Unfortunately, no grey scales of acceptable quality can be obtained. According to the present invention, the data voltages (a,b,c) of the image, are superposed by a high frequency voltage (Hf) of triangle form and together are applied to the electrodes of the liquid crystal display. This method allow to display images with high quality grey scales. To adopt the display for moving pictures, a new method of divisional addressing was found out. The new method allow to double the frame speed, or to double the number of the addressable rows for high definition displays.