BACK LIGHT FOR LIQUID CRYSTAL DISPLAY DEVICE AND LIQUID CRYSTAL DISPLAY DEVICE PROVIDED WITH THE SAME

摘要

PROBLEM TO BE SOLVED: To obtain a back light for a liquid crystal display device providing an appropriate luminous intensity distribution and uniform emission light, and easily manufacturable. SOLUTION: In a light guide plate utilizing reflection on a wedge shaped reflection surface divided by a dividing flat part and light collection effect by a light emission surface having a prism shaped rise and recess, especially a width of the dividing flat part is maintained same and a depth of the groove of the wedge shaped reflection surface is changed according to a distance from an entrance end surface of the light guide plate.