Patent ID: 7567092
Filing Date: 2009-07-28
Classification: G09G

Abstract:
1. An LCD (liquid crystal display) driver comprising: a normal mode circuit for generating a normal mode signal related to a normal image data writing operation of an LCD; a test pattern generating circuit for generating a test mode signal related to a test image data writing operation of the LCD; a selection circuit for selecting one of the normal mode signal and the test mode signal; and a timing controller including a memory storing image data that constructs a normal image pattern or a test image pattern for display on an LCD panel of the LCD in response to an output signal of the selection circuit, wherein the displayed test image pattern is used for a visual quality test, and wherein the test mode signal includes test image data constructing the test image pattern, a test memory selection signal for activating or deactivating the memory a test row address signal and a test column address signal designating a position of the test image data stored in the memory, a delayed test enable signal obtained by delaying a test enable signal for enabling the test pattern generating circuit, and a test write clock signal synchronized with the test memory selection signal, the test row address signal and the test column address signal, wherein the selection circuit is operated in response to the delayed test enable signal.