Sharp has developed an LED device for backlights that can substantially maintain the brightness of the LCD panel while expanding the color range by 25. The liquid crystal cell is unchanged, and only the LED device is used on the backlight, so that the liquid crystal panel with a color expression range of NTSC (CIE1931) ratio of 90 can be realized. A total of four products have been developed, two of which are used for small and medium-sized LCD screens (0.4mm thick and 0.6mm thick), and the other two are used for large LCD screens (edge-lit and direct-lit). The industrial sample price is 40 yen (including tax), samples will be available from December 24, 2013, and mass production will begin in April 2014.
LCD backlights originally used LED devices consisting of blue LED chips and yellow phosphors. The color range of liquid crystal panels using this backlight is NTSC (CIE1931) compared to 72. Sharp used blue LED chips. The LED device composed of the red phosphor and the green phosphor realizes a color expression range of NTSC (CIE1931) ratio of 83 on a part of the wide color gamut liquid crystal panel, but in this case, the problem is that the screen brightness ratio is yellow fluorescence. The liquid crystal panel of the body is reduced by 20.
Sharp's combination of a red phosphor and a green phosphor with a new material on the blue LED chip takes into account the wide color range and high brightness of NTSC (CIE1931) over 90. When using a 0.4mm thick product for small and medium-sized liquid crystals, according to Sharp, the brightness of the liquid crystal panel is 97 when using a yellow phosphor, which can basically maintain the original brightness. Moreover, due to the wide range of color expression, a stereoscopic effect can be displayed. Image.
Sharp said that the reason why the product can increase the brightness compared to the previous wide color gamut liquid crystal panel is to develop a new material with high conversion efficiency (the ratio of the light emitted from the blue LED chip to the phosphor converted to different wavelengths). Red phosphor and green phosphor. According to reports, the red phosphor is a phosphor manufacturer developed specifically for Sharp, and the green phosphor is jointly developed by Sharp and phosphor manufacturers.
In addition to high conversion efficiency, the peak intensity of the red spectrum is also increased, and the peak width is reduced, thereby achieving a spectral distribution in which the red and green light peaks overlap. As a result, the color performance range has also been increased from NTSC (CIE1931) to 83.
Guangzhou Dongsui Auto Accessories Co., Ltd. , https://www.dongsui4x4.com