Since the fine Luminescence of LED, LED components can not only cause direct display of equipment, in recent years, LED has also been gradually introduced into the existing flat-panel display technology, in particular liquid crystal display technology, are very likely to be LED by a Monopoly industries. LED backlight color saturation better, fast response time, Louguang effect of the weaker. If by increasing the contrast, regional and other means of control, performance much better than cold cathode fluorescent lamp (CCFL). And the cold cathode fluorescent lamps containing mercury and other harmful substances, LED comparison more environmental advantages. LED has been in many mobile devices used by small-size panels in popularity.。 And notebook computers and large-size LCD TV panels with backlight LED industry will be the next heavyweight applications.
At present LED technology in the field of LCD applications, mainly using alternative LED LED components before the CCFL fluorescent light, as the LCD backlight equipment. And if we once again broken down, it can be issued in accordance with the LED light colors, divided into white LED backlighting and RGB-LED backlighting two.
White LED backlighting technology
Above, we have referred to the LED in the development process is one of the breakthrough can be achieved the goal of a white light. LCD equipment in the imaging principle, a white backlight, a liquid crystal layer, and then through the R / G / B color filter membrane, become independent of the primary colors. In this process, the final decision color liquid crystal display equipment is not the key liquid crystal layer, but the backlight LED quality. Backlight each of the RGB primary color spectrum of light the higher the purity, in the final order to restore the more pure colors, only to restore the pure RGB three primary colors can be deployed to the pure and true color effect.
The traditional CCFL light source in the luminous quality is not satisfactory, the reduction is not pure color, color used to measure the scope of the domain, the general in NTSC geometric 72 percent, even through the use of improved CCFL light source, Can only reach about 90% geometric NTSC color gamut range, which caused the real world of bright, true color LCD television can not be reduced, thus affecting the image quality. And through the use of high-quality white LED backlight LED, LCD TV color gamut of the NTSC geometric can easily reach around 100 percent, the color effect of significantly enhancing the role.
Sony VAIO SZ notebook using white LED structure before and after comparison
The use of white LED Another advantage is to reduce the thickness of LCD panels, it is ideal for mobile devices on the pursuit of light. In introducing the advantages of LED technology, there is an LED volume can be done is very small. In the liquid crystal display devices, LED backlight board the shape and size LCD panels will be in accordance with the shape and size vary. LED backlighting lamps are basically rectangular plate or a long strip. It is at the bottom and side of the luminous luminous two basic structure. LED side of the main structure for the long and narrow strip of the backlight board (general length of more than 2 times the width), while those at the bottom of luminous structure mainly used for almost the length and width of the backlight board. LED light, the light into the transparent plexiglass so that the whole luminous surface will be able to see light, this is known as side-effects. PMMA beads made at the top of granular, make the whole surface of the LED light more evenly. Plexiglass at the top of a layer of milky white transparent plastic film, will enable a more gentle light. 背光灯板两侧边用银色遮光胶带封住。 Backlight with silver-plate on both sides of shading tape shut. Each LED LED modules include two series of diodes, are composed of a number of LED array (depending on the length of backlight plate may be). To notebooks as an example, a white LED as the LCD backlight after, LED backlighting to multiple sources in order placed at the bottom, to replace the traditional CCFL small lamp, SONY VAIO TX notebook, on the use of 40 The LED-LED components. LED lamps instead of using small, the light guide plates and a thick wedge-shaped design was cancelled, can be used to turn light guide plates uniform thickness and can drop the overall thickness of the end.
Another advantage of LED's - energy saving, is also favored by the application. The notebooks and other mobile products, the use of LED整机can increase the use of time, thereby enhancing the movement is sustainable. But for TV, at this stage the use of LED backlighting and can not significantly reduce power consumption, mainly because of the demands of television on high brightness, in order to meet the needs of brightness, it is necessary to increase the number of LED components, leading to the overall power does not appear obvious Lower. However, I believe that with the higher luminous efficiency of the emergence of LED components, LCD TV will use the relatively small number of LED components will be able to achieve high brightness, power consumption will be sharp decline.
RGB-LED backlighting technology
As RGB three primary colors can be deployed to nature in any one color, in addition to white LED, LCD in the field, there is also used to issue R / G / B Three Dan Seguang the backlight LED technology.
RGB-LED backlight, is to be sent high-grade red, green, blue light of LED components, to achieve the traditional CCFL light source can not achieve the broad-domain. At present the mainstream RGB-LED backlight can reach 105 percent of the NTSC color gamut, but as long as the use of more robust LED devices, now can achieve 120 percent over the scope of the NTSC color gamut. This is to restore the image-based TV, will be a very effective means of enhancing quality. It can be foreseen is that, RGB-LED in the next few years will become a major LCD TV breakthrough in the direction of development.
In addition to better color gamut performance of a RGB-LED light source can also effectively enhance the contrast of TV and achieve more accurate color gamut and a stronger sense of the screen level. Since the whole backlight Yuanyou many tiny LED LED modules, each of which can achieve devices precise brightness control. According to the original screen characteristics of small areas of brightness that become possible, for example, in a strong contrast of the dark screen, dark region of the Department of LED backlighting can be completely closed, and the bright regions of LED backlighting to achieve high brightness output, which brought To enhance the contrast effect will be adopted CCFL light of the past, LCD TVs can not match the.
SONY TRILUMINOS technology is the RGB-LED backlight
In the field of TV, has introduced a number of manufacturers using RGB-LED backlighting source of commercial products, such as Sony's latest 70-inch LCD TV 70 X300A, on the use of the RGB-LED backlight. Use of LED can quickly shut down, subregional flexible control, the advantages of adjustable brightness, not only from the traditional dark LCD TV screen of the shortcomings of the poor level of performance, demonstrated by the beautiful color effects, and have any of the existing LCD TV started Sufficient distance.
As can be issued R / G / B-three primary colors, more manufacturers plan to abolish LCD TV occupy the higher cost of color filter, but the technology has not yet entered the stage of the real business, it is also necessary market and the test of time .
Overall, LED lighting technology used in both areas, or show support areas, or equipment used directly for the show, all through its own access to the advantages of traditional equipment can not match the performance. 。 However, the good side of everything there, of course, there will be bad side. As a new generation of lighting technology, LED is not perfect, the above-mentioned several areas of application, there are still some problems.