PRODUCTION OF OPTICAL RECORDING MEDIUM

摘要

PURPOSE:To obtain a method which executes the initial crystallization of a recording layer in a manner as to prevent the recording from remaining without being erased at the tie of erasing of said recording by changing the reflectivity level of the initial crystallization state of the recording layer from the inside circumference to the outside circumference of the optical recording medium to a specific state. CONSTITUTION:The optical recording medium layer is subjected to the initial crystallization treatment while the recording medium is rotated under the conditions under which the reflectivity of the initial crystallization state is constant at the distance r (mm) from the center of rotation on the disk up to the projection region of a laser beam within the range of the equation I and that the reflectivity of the initial crystallization state decreases with an increase in the radius at the distance (r) within the range of the equation II at the time of producing the optical recording medium which makes recording, erasing and reproducing of information by utilizing the change in the optical characteristics of the crystalline state and noncrystalline state of the recording layer provided on a disk-shaped substrate. The reflectivity level of the initial crystallization state is thus changed to the specific state from the inside circumference to the outside circumference of the optical recording medium, by which the remaining of the recording of the optical recording medium for executing the recording by the laser being without being erased at the time of the erasing of the recording is obviated.