| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a CD-RW enabling high-speed recording faster by 24 times or more while maintaining the compatibility of a conventional CD-RW standard and a rewritable DVD standard, a rewritable DVD enabling high-speed recoding faster by 6 times or more, and its recording method. <P>SOLUTION: The rewritable optical recording medium is constituted of a substrate and a phase-change recording layer wherein the part of a crystal state is set as an unrecorded state/erased state and the part of an amorphous state is set as a recording state, and FEM-modulated information is recorded by applying a recording light and forming an amorphous mark in the groove. Assuming that the linear velocity of 1.2m/s to 1.4m/s is set as a reference speed (faster by one time), when the recording light of a wavelength of about 780 nm is applied through the optical system of a numerical aperture NA=0.5 or NA=0.55 to perform recording at a speed faster by 24 or 32 times than the reference speed, the modulation degree m<SB>11</SB>of a recording signal is 60% to 80%, the upper end value R<SB>top</SB>of the reflectance of an eye pattern is 15% to 25%, and jitters are 35nsec or less. <P>COPYRIGHT: (C)2004,JPO&NCIPI |
