An integrated LED luminance-uniform device for light guide plate applications

Abstract

An edge-backlight unit (EBLU) is applied to as the light device to provide uniform light of liquid crystal display (LCD). Generally, cathode cold fluorescent lamp (CCFL) is utilized to be the light source of BLU. With the advantages like long life, no mercury containing and good endurance of heavy impact, the light emitting diode (LED) is well known as a viable device for solid state lighting. To achieve the market requirement of the thin-film liquid crystal display (LCD) and the green-level product, the LED is replaced the CCFL used in monitor to make display thinner, lighter, no Hg containing. In this paper, the integrated LED luminance-uniform device with right angle microprism structure is proposed that it can make the point-like light to distribute propagating-light line pattern successfully. To optimize the distributions and sizes of microprisms, our designed LED-linear device can achieve an optical efficiency more than 85%, and its light output area is 2.5 times the input light source. Therefore, the LED luminous device with microprsims not only can decrease the LED to save the space, but also enhance the luminous efficiency. In future, an integrated LED luminance-uniform device could make displays thinner and brighter for light guide plate (LGP) applications.