The Research Of LED Backlight Drive And Optical Design

The thesis describes the development trend of LCD TV backlight and LED backlight trends and sources in the international and domestic development of the status quo,to discuss the technology advantages of LED backlight vs CCFL backlight, given the LED light-emitting mechanism and related features,discusses the issue and will Preparation of the optical, thermal,visual and color theories.In this paper, through the use of ROHM's constant current source driver IC BD9202EFS to create LED backlight driver model, to find the problems and key technologies, which may be encountered in the process of the devising of the LED backlight for large LCD-TV, with the possibility to do exploratory and experimental work for the production of LCD TV, which is use of LED backlighting. The thesis completed the LED driver circuit of the 42-inch LCD TV.The thesis completed the optical design of the backlight modules. the former is to calculate the amout of flux and energy for each color LED, considering the influence of the LCD-panel, optical films and temperature;the latter is to determine the influence of the distance,which between LED and optical films and between the LED-array units,to the brightness uniformity.In order to obtain stable and exact amount light output,theses completes the design of the circuit of the backlight drive and optical design of the backlight module.Putted the LED driver and LED backlight into machine, after EMC test,aging test, optical test, the results of the test confirms the LCD TV with LED brightness have the advantage of uniformity,high contrast,wide color gamut,and low power consumption.In this paper,the theoretical derivation and the process of establishing a prototype lay the foundation of the further research and development and promoting use in the large-size LED backlight.