MANUFACTURING METHOD OF LIGHT GUIDE PLATE, LIGHT GUIDE PLATE, AND LIGHT EMISSION TYPE SIGNBOARD USING SAME

摘要

PROBLEM TO BE SOLVED: To prevent irregularity from occurring on a surface by adjusting nonuniformity of a reflecting pattern when the reflecting pattern is formed by ultrasonic machining. SOLUTION: A manufacturing method of a light guide plate 3 emitting, from a principal surface, light entered from an end surface comprises: a formation process of forming a recessed-part group comprising a plurality of recessed parts 11 deflecting the advancing direction of the light entered from the end surface by bringing a predetermined horn 101 for ultrasonic machining into contact with the principal surface of the light guide plate 3; and an adjustment process of nearly-uniformly adjusting the size of the plurality of recessed parts 11 constituting the recessed-part group by bringing the horn 101 for ultrasonic machining into contact with the recessed-part group formed on the principal surface of the light guide plate 3 by the formation process. COPYRIGHT: (C)2009,JPO&INPIT