| 摘要 |
PROBLEM TO BE SOLVED: To provide a back light system of a liquid crystal display panel which improves a utilization rate of rays. SOLUTION: This back light system has one or plural light source parts 5, an approximately flat front surface 9 on the side facing the liquid crystal display panel 1, a rear surface 10 on the side opposite to the liquid crystal display panel 1 with respect to the front surface 9 and a light transmission body 3 having one or plural ends adjacent to the respective light source parts 5. The rear surface 10 has plural parallel parts parallel with the front surface 9 and connecting parts connecting both adjacent parallel parts. The respective connecting parts on the rear surface of the light transmission body 3 are composed of such plural slopes which are approximately perpendicular to a longitudinal direction and form continuous roof shapes and attain prescribed angles of inclination with the respective parallel parts. The angles formed by the normal of the slopes and the incident rays on the slopes are increased, by which the rays transmitted directly through the slopes and radiated to the outside of the light transmission body are decreased. |
