White LED technology has made remarkable progress. At present, products with light efficiency of 100lm/W have been produced, exceeding fluorescent lamps and HID lamps. Products with luminous flux of single white LED above 100lm are also emerging, and their application in the lighting field is accelerating. Lexus LS600h car headlights adopts five white LEDs with luminous flux of 400lm, which achieves the necessary brightness of low beam. These products were developed by Suu Manufacturing Company.
The headlamp developed by Suu Manufacturing Company and equipped on Toyota "Lexus LS600h" uses five white LED lights as auxiliary lights. Each white LED lamp uses a white LED module.
Some problems have been encountered in the development process, such as ensuring brightness, reducing power consumption and taking heating countermeasures. The brightness needs to be at least 20Mcd/m2, which is the same as that of halogen lamps, while the white LED is only a few Mcd/m2. For this reason, the package is equipped with four large-size blue LED chips about 1mm square, each chip can input 2.5W (input current is 700mA), and the total power of the whole LEDheadlamp LED package is10 W. Therefore, a brightness of 25Mcd/m2 was obtained.
However, if high power is supplied to each chip, the luminous efficiency will decrease. Compared with HID lamps, the headlights of Lexus LS600h have a luminous efficiency of only 40lm/W, which means high power consumption. Therefore, Suu Manufacturing Co., Ltd. has improved the effective use of light. The specific method is to endow a plurality of white LED lamps with different light distribution characteristics and make light distribution patterns. Compared with making a complicated light distribution pattern on one lamp, the light loss is reduced.