| 摘要 |
PROBLEM TO BE SOLVED: To realize high-speed access to a ROM area and a RAM area without accompanying a seek to an optical head, by providing an information-recording track extended in the circumference of the center of a disk recording medium, an information reproduction recording area on the track and an information record reproduction area continuous with the recording area. SOLUTION: Recording tracks Tr1-Trm, ROM areas Aro exclusive for reproduction, address areas Aad and RAM areas Ara that can be recorded and reproduced are continuously repeatedly provided in parallel to a scan direction Da. The areas Aro, Aad and Ara are formed at wind parts of the tracks. A partial record area APR is thus constituted. A bit mark Mro is formed at the ROM area Aro, and a bit mark Mra in a crystal state and an amorphous state is formed at the RAM area Ara with the utilization of a phase change of a recording film. A guide groove Gg is formed every other rounds to the wind part of the track Tr at the RAM area Ara to let laser beams trace the track Tr. Accordingly, data can be recorded to both a land and a groove track formed by one guide groove Gg. |
