A Research on New Measurement System for the Grayscale Response Time of LCD

In this article, a new measurement and system for the grayscale response time of LCD was proposed based on the methods of measurement for Digital Television Flat Panel Display and TCO´06 Media Display. The luminance signal of LCD was detected by a photoelectric probe, and converted to analog signal. The analog signal difference of the luminance levels between two neighborhood grayscales was not big enough to calculate the grayscale response time correctly. The analog signal was processed by a special designed circuit. The analog signals were amplified first. The amplified signals were add to the subtraction circuit. The lesser signal of the lower grayscale was subtracted. The difference of the signals was detected and amplified farther, and then converted to digital. The reference voltage of the subtraction circuit and amplify multiples were under the control of the single chip. Finally, the digital signals were transmitted to computer. The computer dealt with the data and calculated the grayscale response time of LCD. The experimental results showed that the repeatability error of the response time with this method was less than plusmn0.5 ms, and the accuracy met the requirements of methods of measurement for digital television flat panel displays and TCO´06 completely.