Research Of Matrix Backlight Design And Application

Liquid Crystal Displays(LCD)have become mainstream in the flat-panel display industry,its typical components include backlight,polarizers,liquid crystal layers,color filters,etc.Because of the transmission mechanism of the liquid crystal display,no matter what the display content is,the backlight is always in a state of light,and the light effeciency is extremely low.And to realize the color display,the liquid crystal display usual y adopts the color filter to realize the red,green,and blue sub-pixels,so the light efficiency loses two thirds again.Adopting a matrix backlight is considered as an effective way to improve the light efficiency and picture quality of liquid crystal display devices both at present and in the future.At present,in some high-end liquid crystal display products,the matrix backlight structure is used to adjust the backlight intensity according to the content of the screen,which can reduce the power consumption and increase the contrast.The group further uses red,green and blue matrix backlights in combination with high refresh rate LCD panels to propose the primary desaturation algorithm that realizes the backlight dynamic adjustment of the local color and brightness and cooperative distribution of liquid crystal drive signals,by which the liquid crystal display without color filters is realized,thereby improving light efficiency,and simultaneously having high dynamic contrast and high pixel resolution advantages.In this paper,the effect of matrix backlight parameters such as field primary colors,duty cycle,refreshing rate,and division number on the display quality are systematically studied through visual perception experiments and simulation algorithm.Two visual perception experiments are designed on two liquid crystal displays at 120 Hz and 180 Hz respectively,the effect of matrix backlitht field primary colors on color breakup and the thresholds of color breakup visibility along different hue directions is studied by adjusting the color field combination.Another perceptual experiment is designed on the 720 Hz LED display independently developed by the laboratory,with changing video content,the relationship between color breakup and backlight duty cycle,backlight refresh rate is investigated.On this basis,further aiming at the content of natural images,using the perception index of color breakup,the relationship between color breakup and backlight division number in the primary desaturation field sequential color display is investigated.This paper sets up a set of regional color adjustable matrix backlight test platform.Through the analysis of the parameters such as backlight emitting color and luminous efficiency,the selection of backlight beads is completed,and the design of the matrix backlight driving circuit is finished on Altium Designer.Lastly,the brightness distribution and the color gamut of matrix backlight are measured and analyzed,a display prototype system based on the designed matrix backlight and FPGA development board is built,the function of displaying the natural image is realized.