| 摘要 |
PROBLEM TO BE SOLVED: To obtain a uniform high recording and reproducing characteristic by changing stepwise a reduced pressure of an injection molding pressure after the injection molding. SOLUTION: A stamper 26 is mounted on a surface of a signal face mirror member 11, and a cavity 14 is closed by moving a read face mirror member 12 so that a molten resin is injected into the cavity 14 through a gate 15. The injection molding pressure is applied, e.g. in five stages: in a first step the injection molding pressure is 13 tons or more and the injection molding pressure time is 0.4 sec or more; the switching time to a second step is 0-5 sec, the reduced pressure is 0-13 ton and the reduced pressure time is 0-3 sec; the switching time to a third, fourth, and fifth steps 0-5 sec respectively, the reduced pressure 0-13 ton respectively and the reduced pressure time 0-5 sec respectively. This results in substantial uniformity in an each CNR in the inner circumferential portion, intermediate circumferential portion, and outer circumferential portion of a magneto-optical disk. |
