| 摘要 |
PURPOSE: To lighten a back light device and to uniformize an intrasurface luminance distribution of lighting light. CONSTITUTION: When a fluorescent lamp 1 is lighted, light from the fluorescent lamp 1 enters space S while repeating reflections between a reflection layer 12 and rear side reflection plate 10. Then, a part of the light leaks out of many opening parts 13 formed on the reflection layer 12 to the outside, and irradiates an object to be lighted (e.g. a transmission type liquid crystal panel). Further, a ratio (opening ratio) of the occupied opening parts 13 is so set as to become larger according as the part 13 goes apart from the fluorescent lamp 1. Then, though the incident angle θ1 becomes smaller according as a part concerned goes apart from the fluorescent lamp 1, since the opening area of the opening part 13 at the part concerned (the part separated from the fluorescent lamp 1) is large, the leakage amount of the light is secured to an extent over a prescribed amount. Thus, the intrasurface luminance distribution of the lighting light is uniformized without arranging a light transmission body formed of acrylic, etc., in the space S. |
