Patent ID: 7391395
Filing Date: 2008-06-24
Classification: G09G

Abstract:
1. A super twisted nematic (STN) liquid crystal display (LCD) driver that drives an STN LCD comprising: a sub frame counter, which counts a number of sub frames in a frame in response to a clock signal and generates a sub frame flag signal every time each sub frame is counted in the frame; an N clock counter, which receives an N-line signal and generates an N-line flag signal every time the number of N-lines counted is N in response to the clock signal; a frame counter, which receives a frame rate control (FRC) selection signal, counts the number of the sub frame flag signals received from the sub frame counter, and generates a frame flag signal every time the number of the sub frame flag signals counted is n; and a liquid crystal polarity inversion signal generator, which selects one of the sub frame flag signal and the N-line flag signal in response to a selection signal, and further selects the frame flag signal which inverts a level of a liquid crystal polarity inversion signal in the frame, and generates the liquid crystal polarity inversion signal that inverts a polarity of an STN liquid crystal of the STN LCD in the frame.