Method for preparing optical recording medium

Abstract

An improvement in production of an optical recording medium of phase change type is provided. In the present method, the step of repeated recording and erasing which had to be carried out after initialization and before shipment in the conventional process is eliminated. The optical recording medium produced by the present process retain good properties after repeated overwriting. In the process of the present invention, the prior art initialization step is replaced by modification treatment and the subsequent crystallization treatment. The modification treatment is a step wherein non-crystalline recording layer formed by sputtering is melted and cooled to change the crystal-lographic state into a non-crystalline state which is different from the non-crystalline state immediately after the formation of the recording layer. The crystallization treatment is a step conducted after the modification treatment wherein the recording layer in non-crystalline state is heated for crystallization.

Dependencies are inferred from the claim text.