Phase-change optical recording medium and its writing with high reliability after long period use and/or high environmental temperature storage

Abstract

In the phase change type optical recording medium of the present invention, loss of reliability by high-temperature storage is prevented, and self-erasure (a phenomenon of partial erasure of the record mark by heat diffusion in the lateral direction during the irradiation of the recording laser beam) is suppressed. There is thus provided an optical recording medium designed for use in a drive system wherein overwriting is conducted at a linear velocity V.sub.0 which satisfies the relation: 0.6<V.sub.2nd /V.sub.0 <1.25 when V.sub.2nd is the overwriting linear velocity at which the frequency component corresponding to the second harmonic of the frequency of the recording signal used for the overwriting is minimized when the record marks formed by the overwriting are reproduced and measured for such frequency component. Also provided is an optical recording medium adapted for use in a drive system wherein overwriting is conducted at a linear velocity V.sub.0, wherein trailing edge of the record mark formed exhibits a jitter smaller than that of the leading edge when the medium is overwritten at the linear velocity V.sub.0.

Dependencies are inferred from the claim text.