Mainly by the light source, guide plate, optical diaphragm, plastic frame and so on. The backlight has the characteristics of high brightness, long life and uniform luminescence. At present, there are mainly EL, CCFL and LED three kinds of backlight types, according to the distribution of light source different positions are divided into side light and straight down type.
As the LCD module continues to develop to a brighter, lighter and thinner direction, the lateral light type CCFL backlight has become the mainstream of the current development of the backlight. The electroluminescent (EL) backlight is light in weight and provides uniform and consistent light. Its power consumption is very low, the required operating voltage is 80~100Vac, and the inverter that provides the operating voltage can transform the input of the 5/12/24Vdc into an AC output. However, the service life of the EL backlight is limited (the average service life under 50% brightness conditions is 3,000-5,000 hours, and the service life at a higher brightness level will be greatly reduced), so the ideal output voltage and frequency of EL back illumination is allowed to increase with the aging of the EL bulb, This extends the effective service life of the display using EL's back illumination light source.