Introduction To LED Backlight

LED backlight uses light-emitting diodes as the backlight light source, which is the most promising technology to replace traditional cold cathode fluorescent tubes in the future. Light-emitting diodes are made of several thin layers of doped semiconductor materials. One layer has excess electrons, and the other layer lacks electrons to form positively charged holes. During operation, current flows through, and electrons and holes combine with each other. The energy is released in the form of light radiation. Light-emitting diodes with different light-emitting properties can be obtained by using different semiconductor materials. Light-emitting diodes that have been put into commercial use can provide colors such as red, green, blue, cyan, orange, amber, and white. Mobile phones mainly use white LED backlights, while the LED backlight sources used on LCD TVs can be white or red, green, and blue. Multi-color LED backlights can also be used in high-end products to further improve the color. Expressive, such as six primary color LED backlight source. The advantage of using LED backlight is that the thickness is thinner, about 5 cm, and the color gamut is also very wide, which can reach 105% of the NTSC color gamut. . At the same time, the other LED backlight light source also has a life of 100,000 hours. The main problem that restricts the development of LED backlight is cost. Because the price is much higher than that of cold fluorescent tube light source, LED backlight light source can only appear in foreign high-end LCD TVs.

Between the high cost of LED backlight source, a manufacturer has introduced improved CCFL (cold cathode fluorescent lamp) backlight LCD TV products, representative of which are Sony and Sharp. Sony's wide color gamut cold cathode backlight tube (WCG CCFL) increases the purity of green by adding phosphorus to the silver light of ordinary cold cathode backlight tubes, making the color gamut wider. The most prominent thing is that the greenness of the TV is quite dazzling. . However, the disadvantage is that the high cost investment is not acceptable to ordinary families. Some Samsung products also have this technology. And Sharp chose a low-cost idea. Sharp's eighth-generation panel products use four-wavelength backlight technology (which was previously used in 65-inch products). The principle of Sharp's four-wavelength backlight is to increase the expressive power of red by adding red LED light-emitting diodes between the lamps. The cost of red LED light-emitting diodes is very low, which is more clever than Sony. This also makes it obvious that Sharp's panel will be reddish in a completely black state!