Abstract
Backlights illuminate the LCD panels from the rear, and generally consist of a light source and optical components. Mass LCD backlights have used cold-cathode florescent lamps (CCFL) for this purpose, but now we are switching to LEDs. We only convert the light source of CCFL into LEDs. We use AutoCAD software to establish 7-inch backlight modules and analyze optical characteristics of 7-inch backlight modules in TracePro software. Four steps for designing LED 7 inch backlight are below: Step one: Model 7-inch backlight modules in AutoCAD. Step two: Find the uniform output plane using CCFL light source in TracePro software. Step three: Instead of CCFL, we use White LED for light source. Step four: Use three RGB colors LEDs generating white light. Finally, we can get three types of 7-inch backlight modules. Three types of 7-inch backlight modules are CCFL backlight modules, White light LED backlight modules, and Three RGB colors LED backlight modules.