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LED backlight: innovative survival in the crack
In the increasingly developed and mature LCD industry chain, the labor-intensive features of the LED backlight industry and relatively low entry barriers have led to the current fierce competition in the backlight industry. On the one hand, upstream key materials such as optical films are still in the hands of a few manufacturers, material prices are difficult to fall, product costs remain high; on the other hand, there is also pressure from downstream customers to continuously demand price reduction. Under the tremendous pressure on both ends of the industry chain, the profit margin of backlight module products is getting smaller and smaller, and the operation and survival of some manufacturers, especially second-tier manufacturers, are getting more and more difficult. How to enhance product competitiveness through technological innovation has become a matter of life and death for LED backlight companies. Both the sidelight type and the direct type have a sharp decline in LED prices, and the driving force to reduce costs by reducing the number of LEDs is waning. In the next few years, the application of LED backlights in mobile terminals and TVs will continue to grow. Hou Yan, general manager of Display Lighting Division of BOE Optoelectronics Technology Co., Ltd. told reporters that it seems that in the notebook market, traditional CCFL backlights are almost completely replaced by LED backlights; in the large-size desktop display and TV market, LED backlights It is expected to completely replace CCFL backlights this year. As early as 2005, Sony and Sharp introduced the RGB-type direct-lit LED LCD TV, but it was not accepted by consumers because of its high cost. In 2008, Samsung developed a side-lit LCD TV based on white LEDs, which was greatly reduced in cost and achieved success, and began to lead the development trend of LCD TVs. In 2012, the TV lens developed by Enplas made the LED usage of the direct-lit backlight greatly reduced, the cost was lower than that of the edge-lit backlight, and the direct-lit LCD TV was reborn. Yan Xiaoming, vice president of Shenzhen Ruifeng Optoelectronics Co., Ltd., told reporters that the LEDs in the edge-lit backlight module are located on the side of the backlight module, and the light is emitted from the surface of the liquid crystal display through the light guide plate, while the direct-lit backlight module is The LED is located at the bottom of the backlight module, and the secondary lens is used to enlarge the illumination angle of the LED, thereby reducing the amount of LED. "It should be said that these two methods have their own advantages and disadvantages." Li Xiufu, deputy dean of the research institute of Suzhou Dongshan Precision Manufacturing Co., Ltd. and director of the Institute of Backlighting, said in an interview that "the side-light module is compatible. High reliability, direct-type modular machine with good strength and support for large size; side-light integrated machine is easier to achieve ultra-thin and narrow frame design, straight-down one-piece assembly is simpler and has a price advantage." Then these two technologies In which direction are the mainstream companies of the route working together? Xiaoming said that with the change of the light-input mode of the edge-lit backlight module, it puts higher requirements on the brightness, power and heat dissipation capability of the LED. The light-emitting LED package tends to be more standardized, the power of the same-sized package product is increasing, and the material performance and structural performance of the LED bracket are continuously increasing. While the direct-lit backlight technology is moving toward low-mixing and low-cost, the LED power is continuously increased from 1W to 3W, the material of the bracket is also developed from PCT to EMC, and the illuminant is close to the electric light source, and the diameter of the illuminating surface is continuously reduced. The chip from the dress to the flip chip also enhances the heat dissipation capability of the LED. "The backlight design of TV usually needs to be trade-off between cost, thickness and brightness, and various technical routes have their own advantages and disadvantages." Hou Yan said, "but specifically to the way of entering the light, it is certain that with The sharp drop in LED prices, the driving force to reduce costs by reducing the number of LEDs is waning.†The challenge of OLED and LED display challenges the continuous reduction of costs through technological innovation, thus winning market space with high cost performance. Although there are still many defects in each, the emergence of self-illuminating OLEDs and LED displays has brought a big impact to the LED backlight module industry. Moreover, it is not only the advantage of self-illumination, high color gamut, high contrast, wide viewing angle, flexibility of OLED screen, and large size of LED screen, which make LED backlight module enterprises like thin ice. How to deal with the challenges brought by OLED and LED display? The mainstream enterprises have consistently checked the gamut. The color gamut, ie the color saturation, refers to the ability of the display to restore natural colors. The higher the color gamut, the more vivid the image is, the closer it is to the natural color. Generally, the color gamut of a liquid crystal display is about 72%, and the color gamut of an OLED can reach more than 100%. So how to improve the color gamut of the LED backlight LCD screen? Yan Xiaoming said, first, with a new narrow half-wave width red and green powder combination, the color gamut is about 85%; the second is to add green chip compensation, the color gamut can reach More than 95%; the third is to use the quantum dot phosphor solution, you can achieve more than 100% color gamut. The method is there, but each has its own limitations. Qiao Mingsheng, technical director of Qingdao Hisense Electric Co., Ltd., said in an interview that the first solution is simpler to implement and the cost is relatively low, but the achievable gamut value is also lower; the second two-color chip solution can be The implementation of the gamut value is still relatively high, but the driving is complicated, the life of the two chips is inconsistent; the third quantum dot technology solution can achieve a high color gamut value, but the requirements for material packaging are also high, and the environmental protection aspect cannot be satisfied for the time being. Claim. "Improving color gamut is only one of our efforts. Ultra-thin body, ultra-narrow bezel, high brightness, ultra-low power consumption, curved surface, etc. are the countermeasures for LED backlight LCD technology to meet the challenges of new technologies. The ultimate goal is still Through technological innovation, the cost is continuously reduced, and the market space is won with high cost performance.†Many experts reached a consensus on the development direction of backlight technology.