Design Of FPGA-based LCM Signal Generator

With the development of display technology,liquid crystal display(LCD)has become the mainstream display devices,and its market share increased year by year.Thin film transistor liquid crystal display(TFT-LCD)has a unique performance advantage and a highly competitive price advantage to occupy the leading position of the display device.At the same time,the requirements of the TFT-LCD detection technology is becoming more and more strict,and TFT-LCD detection technology has gradually become the focus of the research of liquid crystal manufacturers.The thesis introduces the principle of TFT-LCD display theroy and the image processing in TFT-LCD defect detection system.According to the commonly used image denoising method,this thesis proposes optimization method.At the same time,This thesis designs a signal generator which is suitable for high resolution TFT-LCD detection and mainly used in the production of liquid crystal display detection,as well as to demonstrate the display of products to customers.The thesis' s main work is concluded as follows:1.Deep understanding of TFT-LCD defect detection technology and research status.Study of the commonly used image acquisition denoising algorithm in TFT-LCD defect detection system.There are standard median filter,switching median filter,Gauss filter,fuzzy filter,etc.In the impulse noise filtering,this paper proposes a switching median filter algorithm based on adaptive threshold,which reduced the number of comparisons and improved the performance of the algorithm.2.In the gauss noise filtering,this paper also proposes an optimal membership function based on fuzzy filter to reduce the complexity of hardware,and uses a kind of median filter and the optimized fuzzy filter combination structure to reduce the Gaussian noise.Finally,using Verilog HDL hardware description language to achieve these algorithms.The experimental results show that the design of the FPGA based image denoising algorithm can meet the real-time requirements of the system,and can better complete the image acquisition.3.Based on deep study of TFT-LCD display theroy.Using FPGA as the control core of the system,the LCM signal generator is designed by using the HDL Verilog language,which included the USB instruction decoding module,Local registers module,SPI communication interface module,NAND FLSAH control module,SDRAM control module,programmable clock control module,RGB interface module and PWM timing signal control module etc.4.Carrying on the debugging of TFT-LCD testing system designed to to successfully drive the LCD screen display.Finally,the results achieved LCD screen test requirements.In this thesis,the design of the FPGA based image denoising algorithm can meet the real-time requirements of the system,and can better complete the image acquisition.The LCM signal generator can drive two MIPI 4 lane LCD module at the same time,and if the two 4lane channel combination,it can drive a 8lane MIPI 2560x1600 LCM.According to the experimental analysis,this design can achieve the highest 4K 3840x2160@30Hz screen RGB signal output.