Rewritable optical recording medium and optical recording method

Abstract

The present invention provides CD-RW which makes high velocity recording at a level of at least 24-times velocity possible, rewritable DVD which makes high velocity recording at a level of at least 6-times velocity possible, and a recording method therefor, while maintaining interchangeability with conventional CD-RW standards and rewritable DVD standards. A rewritable optical recording medium comprising a substrate and a phase-change type recording layer, wherein a portion in a crystalline state corresponds to an unrecorded or erased state, and a portion in an amorphous state correspond to a recorded state, to record EFM modulated information by forming amorphous marks by irradiating the recording layer with a recording laser beam, and wherein recording is carried out by irradiating a recording laser beam having a wavelength of about 780 nm through an optical system having a numerical aperture NA of 0.5 or 0.55, at 24-times velocity or 32-times velocity of the reference velocity, where the reference velocity (1-time velocity) is a linear velocity of from 1.2 m/s to 1.4 m/s, modulation mof record signals is from 60% to 80%, the top value Rof the reflectivity of the high pattern is from 15% to 25%, and jitters are at most 35 nsec.