Driver circuit including test pattern generation circuit in liquid crystal display device

A circuit for driving an LCD device is provided to reduce a test time by testing the LCD device using an internal test pattern generator without using an external test device. A circuit for driving an LCD(Liquid Crystal Display) device includes a normal mode circuit(410), a test pattern generator(500), a selection circuit(430) and a timing controller(440). The normal mode circuit generates a normal mode signal related to a normal image data write operation of the LCD device. The test pattern generator generates a test mode signal related to a test image data write operation of the LCD device. The selection circuit selects one of the normal and test mode signals, and outputs the selected signal. The timing controller includes a memory, which stores image data composing normal or test image patterns displayed on an LCD panel in response to the output signal of the selection circuit.