LIGHT TRANSMISSION PLATE

摘要

PROBLEM TO BE SOLVED: To improve the luminance at the corner parts of a light transmission plate near a non-light emitting part of a light source when the light source has the non-light emitting part and the effective light emission length is smaller than the length at the light incident end face of the light transmission plate. SOLUTION: The light transmission plate 10 has the length L0 approximately equal to the length of a liquid crystal display section 30. A cold cathode tube 20 has electrode parts 22 and 23 at both ends and the length AL1 of the effective light emitting part 21 is smaller than L0. The parts 12 and 13 facing the non-light emitting part opposite to the electrode part within the end faces of the light transmission plate facing the cold cathode tube project from the portion facing the effective light emitting part opposite to the effective light emitting part. The light emitted from near the end the effective light emitting part of the cold cathode tube is made incident on the inside of the light transmission plate from an arcuate portion connecting the portion facing the effective light emitting part and the portion facing the non-light emitting par. These light rays are emitted from the corner parts A and B and improved the luminance of the corner parts A and B.