Automated system for response time optimization and flicker reduction in LCD manufacturing

In order to meet the important requirement of fast response time for LCD-TV applications, the so-called Response Time Compensation (RTC) technique has been widely used. Defining an optimum look-up table (LUT) is a key process step for the application of this technology, but deriving optimized table entries is difficult to do and historically has taken excessive time. Expanding on our algorithmic development work presented at SID'04, we have created a fully automated system for obtaining an optimal LUT. Without requiring any operator involvement, this system quickly and objectively measures the panel under test, calculates optimized LUT values, and programs those values into the panel's non-volatile memory. Additionally, a new flicker minimization algorithm has been developed and implemented in this same system by using a digital potentiometer to set V_com. Using this system, it is possible to optimize panel parameters for all products in the production line, resulting in very uniform image quality for all LCD-TV panels in spite of variations in process conditions.