Backlight Module Of Liquid Crystal Display

LCD products are non-active light-emitting electronic devices that do not have light-emitting characteristics. They must rely on the emission of light sources in the backlight module to obtain display performance. Therefore, the brightness of the LCD is determined by the backlight module. It can be seen that the performance of the backlight module directly affects the display quality of the liquid crystal panel.

The backlight module includes an illuminating light source, a reflective plate, a light guide plate, a diffuser, a brightness enhancement film (prism sheet) and a frame. The backlight modules used in LCD can be divided into two categories: edge-lit backlight modules and direct-lit backlight modules. Mobile phones, notebook computers and monitors (15 inches) mainly use edge-lit backlight modules, while LCD TVs mostly use direct-type backlight module light sources. The backlight module light source mainly uses Cold Cathode Fluorescent Lamp (CCFL) and Light Emitting Diode (LED) light sources as the LCD backlight.

The reflector sheet (Reflector Sheet) is also called the reflector. Its main function is to completely send the light emitted by the light source into the light guide plate to minimize useless loss.

The main function of the Light Guide Plate is to guide the light emitted by the side light source to the front of the panel.

Prism Film is also called Brightness Enhancement Film. Its main function is to refraction and total reflection of each scattered light through the film layer, concentrate it at a certain angle and then emit it from the backlight to act as a screen. Brightened display effect.

The main function of the diffuser is to correct the edge light of the backlight module into a uniform surface light source to achieve the effect of optical diffusion. The diffuser has an upper diffuser and a lower diffuser. The upper diffusion sheet is located between the prism sheet and the liquid crystal assembly and is closer to the display panel. The lower diffusion sheet is located between the light guide plate and the prism sheet, closer to the backlight source.