Back light unit, liquid crystal display, and method for manufacturing light guide plate

摘要

To provide a back light unit, a liquid display, and a method for manufacturing a light guide plate, in which the occurrence of bright lines can be diminished. An incoming surface 11a of a transparent light guide plate 11 is machined into a smooth surface S to correct a manufacturing tolerance during injection molding in order to form an edge portion E into a designed shape. To effectively reduce occurrence of bright lines, the edge portion E preferably has a curvature of radius or a chamfer dimension of 140 [mum] or smaller. The transparent light guide plate 11, a diffusion sheet 5, and a prism sheet 12 configure a back light unit 10 for a liquid crystal display.