| 摘要 |
PURPOSE:To reduce the development of error of signal and at the same time enable to mold even by a smaller size pressing machine by a method wherein transparent resin material is kept under vacuum and fused by the radiant heat of an infrared heater and after that, press-molded and finally released from a mold after being cooled. CONSTITUTION:A bottom force 19 is heated with an infrared heater 22 simultaneously with steam. Becuase a base 18 is heat-retained by the heat of the bottom force 19, transparent resin material 17, the temperature of which is raised by mainly absorbing the radiant heat of the infrared heater 22, fuses itself in uniform temperature by being heated with both the base 18 and heater 22. The fused material 17 is press-molded with a spressing means by engaging a top force 25 heated in advance by steam with the recess 23 of the bottom force 19. The fused transparent resin material 24 is molded into a flat disc and the signal groove provided into the surface 18' of the base 18 is transferred to the disc. After that, the steam circulating through the top and bottom forces is quickly changed-over to cooling water in order to cool the forces. After the forces are cooled down, the bottom force 19 and the top force 25 are open and the base 18 and the press-molded disc is taken out of the bottom force 19 by being ejected by means of an ejecting means provided on the bottom force 19.
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