背光字：back lighting sign
采用LED背光技术，光源放置字体背后，或预埋于字体内部， Use LED back lighting technology, the LED source are insert at the reverse side of surface or pre-installed into the letters
白天保持字体色彩艳丽，夜间背后打光，字体柔和清晰, Keep the colorful signs at the daylight, back lighting make the letters are clear at the night
可实现正面及背面同时发光。 Front and back can be lighted at the same time