To obtain a metal mold capable of absorbing the dimensional tolerance for production of a stamper for molding an optical disk having a good double refractive index distribution by specifying the range of the total volume of the clearance volume in the thickness direction of the stamper and the diametral direction of the stamper.
A molten resin is so packed as to ride over the pawl part 3 of an inner peripheral holder 5 when this resin is injected into the metal mold. At this time, the gas at the dead angle of part of the inner peripheral holder 5 is forced into the clearances A, B between the pawl part 3 and the stamper 1. The optical disk having the good double refractive index distribution is molded without allowing the leakage again in the direction of the molten resin and without the formation of inverted V marks, etc., if the total volume of the clearances A, B is within a range up to 0.2 to 2mm. Then, the optical disk having the good double refractive index distribution is molded without the occurrence of optical defects, etc., and, therefore, the metal mold capable of absorbing the dimensional tolerance for production of the stamper/is obtd.
KOBAYASHI TOSHIMI
SAITO MAKOTO
