| 摘要 |
<p>A rewritable compact disk provided with a rewritable area for compatibility with a CD-RW, that is a RAM area (105) and a read-only area, that is a ROM area (104) on the same disk side, wherein a phase-change recording layer is provided to both the RAM and ROM areas, a wobble groove is formed in the RAM area, information is recorded in the form of amorphous marks formed by projecting a recording light beam, information is recorded in the form of an array of prepits in the RAM area, and the ratio |I1-I2|/|I1-I2|a of the push-pull signal value before the recording of the RAM area to that after the recording lies in the range between 1.05 and 2.0 when measured by means of an optical pickup used for wavelengths from 770 to 790 nm and having a numerical aperture of the objective of 0.49-0.51 or the ratio |I1-I2|a/|I1-I2|ROM of the push-pull signal value after the recording of the RAM area to that of the ROM area lies in the range between 0.78 and 1.3 when measured by means of the optical pickup.</p> |
