Patent ID: 7872409

Claim:
A light emitting diode, comprising: a dual-wavelength chip for generating a first wavelength light and a second wavelength light; and an optical thin film, disposed above the dual-wavelength chip, for receiving at least one of the first wavelength light and the second wavelength light so as to generate a third wavelength light to mix with the first wavelength light, the second wavelength light, and the third wavelength light to produce a monochromatic light, wherein the optical thin film comprises quantum well structures and a plurality of windows to let the first and second wavelength lights pass through and a lumen ratio of the first wavelength light, the second wavelength light and the third wavelength light is adjusted by predetermining a square measure proportion of the windows to the quantum well structures, wherein the lumen ratio satisfies the following equation: the first wavelength light:the second wavelength light:the third wavelength light=1:y:x; and y≅ 1.67 x+ 4.8.