Patent ID: 7440380
Filing Date: 2008-10-21
Classification: G11B

Abstract:
1. A phase change optical information recording medium on which information is recorded through application of light with a wavelength λ=650 nm thereto, comprising: a characteristic such that a degree of modulation which is a value that a reflectance for a portion, at which a longest mark having a maximum mark length is recorded, is divided by a maximum reflectance for a portion at which information is not written when reproducing information by using an optical pickup of a recording apparatus is obtained, said recording of the longest mark being performed by a recording signal which is a multi-pulse sequence including repetitions of heating and cooling pulses and having the maximum mark length, wherein the degree of modulation is lower than a lowest standard value defined by a specification of standards of the optical information recording medium when recording of the longest record mark by the light emitted from an optical pickup is made at a recording speed of V=0.5Vmin, wherein Vmin is a minimum recording speed corresponding to a lowest recordable relative speed between the pickup and the recording medium, wherein the minimum recording speed Vmin is a lowest recording speed guaranteed to prevent from occurring nonsense writing for the optical information recording medium by the specification of standards.