| 摘要 |
To provide a rewritable compact disk having a rewritable area interchangeable with a CD-RW, that is, a RAM area (105), and an area available only for retrieving, that is, a ROM area (104), on the same disk surface, a phase-change recording layer is formed in each of the RAM area and the ROM area, with a wobble groove being made in the RAM area, irradiation is carried out with recording light so that an amorphous mark is formed to record information and information is recorded in the form of a pre-pit string (60) in the ROM area, and further when measured using a wavelength of 770 to 790 nm and an optical pickup whose objective lens numerical aperture is 0.49 to 0.51, a ratio |I131 I2|/|I1-I2|a of values of push pull signals before and after recording in the RAM area is set to be in a range from 1.05 to 2.0, or a ratio |I1-I2|a/|I1-I2|ROM of a value of a push pull signal after recording in the RAM area to a value of a push pull signal in the ROM area is set to be in a range from 0.78 to 1.3.
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