MANUFACTURING DEVICE AND MANUFACTURING METHOD FOR LIGHT GUIDE PLATE

PROBLEM TO BE SOLVED: To provide a manufacturing device and a manufacturing method for a light guide plate capable of preventing rising of molten resin in the vicinity of a notch section in a hill-shape and adhesion of the molten resin to a lower surface of a processing tool in the vicinity of a blade.SOLUTION: The manufacturing device 51 for a light guide plate includes an ultrasonic vibration generation section 85 capable of arbitrarily oscillating and stopping ultrasonics, and the processing tool 21 mechanically connected with the ultrasonic vibration generation section 85 and having the blade 22 for forming a dot-like reflection section on the light guide plate. The processing tool 21 has an eaves section 23 for crushing a molten material extruded by the blade 22 when the blade 22 is pushed into the light guide plate. A lower surface 23a of the eaves section 23 is finished at a level of a surface with a mirror surface or designated surface roughness. The manufacturing device 51 pushes the blade 22 to the light guide plate while applying ultrasonic vibration to the blade 22 by the ultrasonic vibration generation section 85. Then, the blade 22 is pulled out from the light guide plate after temperature of the blade 22 and the light guide plate in the vicinity of the blade falls to or below a softening point by stopping the ultrasonic vibration.