| 摘要 |
PROBLEM TO BE SOLVED: To enhance the brightness by a back light for a liquid crystal, and simultaneously reduce power consumption. SOLUTION: A back light is equipped with a fluorescent lamp 1, a light guide body 2 which radiates outgoing light from the fluorescent lamp 1 toward a liquid crystal plate, a reflection plate 3 which reflects the outgoing light from the fluorescent lamp 1 toward the incident portion 4 of the light guide body 2. The incident portion 4 of the light guide body 2 is formed into a wedge shape the flat face 4a and the slant face 4b of which intersect mutually with an angle of five to 30 degrees. The fluorescent lamp 1 is provided at a position facing to the slant face 4b of the incident portion 4 of the light guide body 2. The reflection plate 3 is composed of first straight line portion 3a along the flat face 4a of the incident portion 4 of the light guide body 2, and a parabola portion 3b extending parabolically from the one end of the first straight line portion 3a, and second straight line portion 3c along the slant face 4b of the incident portion 4 of the light guide body 2. |
