MANUFACTURING METHOD OF LIGHT GUIDE BODY FORMING DIE FOR PLANE LIGHT SOURCE DEVICE

PROBLEM TO BE SOLVED: To provide a method which can easily manufacture a forming die of a light guide body for a plane light source device, having high quality without degradation of image display performance, in case of use as a backlight of a liquid crystal display, without jeopardizing light-emission characteristics from the light guide body, by preventing generation of sticking between a light guide body of a plane light source device and a sheet-like optical deflection element even if the sheet-like optical deflection element is thinned. SOLUTION: The manufacturing method includes a coarse surface forming process in which blast particle is blasted out from a blast nozzle to a forming die member, and a profile printing surface made to have a coarse surface by the forming die member is formed. The coarse surface forming process includes a first blast treatment processing a whole surface of the profile printing surface of the forming die member under given conditions with the use of blast particle, and a second blast treatment processing a whole surface of the profile printing surface under conditions in which at least one condition among various conditions of the first blast treatment is changed, with the use of blast particle same as the first blast treatment. COPYRIGHT: (C)2010,JPO&INPIT