CHROMATICITY CORRECTION BY LIGHT GUIDE PLATE

摘要

PROBLEM TO BE SOLVED: To perform illumination of white color meeting a specified requirement by correcting an unavoidable variation in spectrum of a white light emitting diode as a light emitting source in a surface light source such as a back light of edge light system for improvement of color balance. SOLUTION: This back light 10 having a light guide plate 2 uses the white light emitting diode as a light emitting source. A YAG fluorescent body y is mixed in the light guide plate 2, light injected from the white light emitting diode 1 to the light guide plate 2 is the chromaticity of outgoing light is corrected to a specified chromaticity by the absorbing and exciting actions of the YAG fluorescent body y in a process where the light injected from the white light emitting diode 1 to the light guide plate 2 is route-changed in the light guide plate 2 and ejected from the upper surface 2a thereof. Then the direction of the beams are arranged in Z direction by an X-direction prism sheet 5 and injected on a liquid display panel 7.