Research On TFT LCD Driving And Controlling IC

TFT LCD became a popular Liquid Crystal Display, because of those advantages such aslow-power consumption, low working voltage, non-X ray radiation, lightness, brightness, highcontrast. It is designed with the nonlinear active thin film transistor which controls every pixelindependently. Though realized the principle of TFT LCD display technique, I found that videodata transmitted by driving system can not create sense reflected brightness properly in brain.This paper analyzed and designed on this question. Detailed operation is according to thecharacteristics of liquid crystal, made the video data meet the requirement of brain sense byadjusting DAC reference voltage.This paper chose the color TFT LCD mobile with resolution of 240 RGB×320 as a researchobject, with the Gamma Correction Module and Data-driving Module of mobile driving-chip ofsingle-chip as the designed objective, and drew appropriate conclusions based on analysis anddesign of circuit module in the following aspects:1) This paper illuminated the array principle of Electric Field Control liquid crystalmolecule from physical aspect, and analyzed the display theory and driving methods indetail. Furthermore, the paper divided the system structure of TFT LCD and selected theGamma Correction Module and Data-driving module related to video data brightnessand brain sensory as well.2) Finish the system design of Gamma Correction Module and Data-driving Module. First,based on the analyses of Gamma Correction process, the paper designed Gammacorrection circuit module which produced 64 class grey voltage curve, and the curvecould realize range, gradient and fine adjustment. Second, based on the requirement ofdata-driving circuit, designed the grayscale voltage data-driving module circuittransformed by video data.3) Based on the module of Panel Equivalent Load, this paper deduced and then calculatedanalytical solutions. Include Liquid Equivalent Capacitors LC C,Storage Capacitors s C ,TFT Channel WidthqW , E uivalent Resistor data R,Capacitors data C of data wire. 4) Use the simulation software of ORCAD PSPICE 10.5 and craft of TSMC 0.25μmMixed ? Signal Salicide , and then jointly simulate the Gamma Correction Module andData-driving module. From the result of simulation, Gamma Correction Module canproduce 64-class grayscale voltage which can realize the range, gradient and fineadjustment; besides, the Data-driving circuit can make video data switch to grayscalevoltage of pixel.