Study On The Driving Technology For TFT-LCD

TFT-LCD has being grown up overwhelmingly in the display realm,and its markets expand from big size TVs(or monitors)and small size for mobile phones to middle size field.Middle size has been a new hot R & D point for TFT-LCD.The work of this thesis derived from the 4.5G production line developing project of BOE.This project focuses on the production of middle size TFT-LCD panels and modules.In this thesis,by choosing a 7 inch WVGA panel with the style number AT070NT83 from Innolux as the substrate panel,we designed its peripheral circuits. After tons of research and analysis on the kindred products in the market,we fixed the system structure and the main ICs.We took the "2+1" frame as the final system structure solution.For the part of digital circuit,NT39207 was chosen as the gate driver IC,NT39411 as the source driver IC,and NT 39703 as the main IC of the timing controller.For the part of analog circuit,AAT1165 was chosen as the main IC.AAT1165 can amplify VCOM and support triple channel output for VGH,VGL and AVDD,and all of these are the most important voltages for the driving system.Then we fixed other electric parts to accomplish the total design solution.The schematic circuit diagram, package diagrams and PCB layout was accomplished by the software of Altium Designer 6.0.The Gerber datasheet was sent to PCB manufacturer,then we soldered the parts to the PCB,bonded FPC to PCB,and then rectified the voltages of Gamma and VCOM.Finally,we succeeded in driving the panel.Lastly,we evaluated the module with its electrical and optical parameters by experiments and analysis.The test results show that its power consumption is less 200mW,which is 30%less than others of the same kind;Its color temperature of 9400K reaches the standard of national TV display requirement;Its color coordinates at white points are(0.283,0.293)and its brightness reaches 280nit,its contrast ratio reaches 290:1,color gumut reaches 45%NTSC,which are up to grade.Through analyzing its waveforms of timing sequence,we found that all our ICs' output waveforms are in high quality,implying that the circuit drove the pixel matrix of the panel stably and efficiently.