PRODUCTION OF OPTICAL DISK SUBSTRATE

PURPOSE:To easily strip one face of a plastic substrate which is cured between the 1st mold material and 2nd mold material without injuring the mold surface or substrate by rotating a cam having an elliptical section provided between said mold materials. CONSTITUTION:The stress to wide the spacing between the 1st mold material 1 and the 2nd mold material 2 overcomes the adheive power between plastic and mold surface when the cam 4 is rotated to generate such stress. Compressed air which is cleaned is injected through a vent hole provided with the cam 4 at the point of this time to forcibly expand the adheive surface of the 2nd mold material 2 and the plastic substrate 3 by which the mold material 2 and the plastic substrate 3 are thoroughly exfoliated. The deposition of debris on the substrate surface exfoliated in the above-mentioned manner is obviated and the generation rate of errors is lowered.