Patent ID: 7758228
Filing Date: 2010-07-20
Classification: G02B

Abstract:
1. A backlight unit comprising: a lamp; a light-guiding plate formed at one side of the lamp; a photonic crystal reflecting sheet formed below the light-guiding plate, a surface of the photonic crystal reflecting sheet having a plurality of parts, each part including photonic crystals that receive light emitted from the lamp through the light-guiding plate and selectively reflect light of a different predetermined wavelength in light guided by the light-guiding plate to a liquid crystal panel; and a sheet formed above the light-guiding plate, the sheet having at least one of a prism sheet or a light-diffusion sheet, wherein the photonic crystals are arranged in a randomly shaped pile, and wherein the photonic crystal reflecting sheet comprises a plurality of spherical cavities, each spherical cavity having a particular size and defining a particular color reflecting part, wherein a particular color reflecting part is capable of reflecting a particular wavelength of light according to the size of the spherical cavity.