| 摘要 |
<P>PROBLEM TO BE SOLVED: To realize a back light system of a thin type for surface emitting of white light without luminance unevenness while using inexpensive light emitting diodes as light sources. <P>SOLUTION: The back light system 140 is realized by providing the back light system with the optical filter 10 which is composed of dielectric multilayered films alternately laminated with a plurality of low-refractive index layers, and high-refractive index layers having the refractive index higher than that of the low-refractive index layers and has the transmittance according to incident angles respectively with the incident red light of the prescribed wavelength band, the green light of the prescribed wavelength band and the blue light of the prescribed wavelength band. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
