BACK LIGHT UNIT, LIQUID CRYSTAL DISPLAY DEVICE, AND METHOD FOR MANUFACTURING LIGHT GUIDE PLATE

摘要

PROBLEM TO BE SOLVED: To provide a back light unit, a liquid crystal display device and a method for manufacturing a light guide plate which can decrease generation of bright lines. SOLUTION: The face 11a of a transparent light guide plate 11 where light enters is subjected to machining to form a smooth surface S of the face 11a so that the manufacture error during injection molding is corrected to obtain an edge part E in the form as designed. In order to effectively decrease the generation of bright lines, the radius of curvature or chamfering dimension of the edge part E is preferably controlled to <=140 [μm]. The transparent light guide plate 11, a diffusion sheet 5 and a prism sheet 12 are assembled to constitute the back light unit 10 of a liquid crystal display device.