MOLDING DIE FOR VIDEO DISC

摘要

PURPOSE:To lengthen the life of dies and a stamper as well as keep the initial accuracy of the surface of a disc for a long period of time after being molded by setting an elastic O-ring between the holding ring of the periphery of the stamper and the surface of the stamper. CONSTITUTION:A stamper 3 is built in so that the surface of a mirror block 2 is faced the back of the stamper 3, and a groove is formed in the stamper holdind claw of the holding ring 1 of the periphery of the stamper and an O-ring 17 is built in the groove in order to make the aperture 9 airtight. The stamper 3 is pushed by the elastic force of the O-ring to prevent the intrusion of foreign matter to the aperture between the surface of the mirror block and the back of the stamper.