Patent ID: 7876658

Claim:
An optical-disk device comprising: record means configured to record data onto an optical disk; and management-information-record means configured to additionally write latest disk-management information about the optical disk in a plurality of management-information-record areas provided on the optical disk, wherein when a first management-information-record area of the management-information-record areas is short of a vacant area used to additionally write the disk-management information, the management-information-record means records padding data in an unrecorded area of the first management-information-record area, and additionally writes the disk-management information in a second management-information-record area of the management-information-record areas, and wherein when the first management-information-record area includes an unrecordable area where the disk-management information is at least partially additionally written with difficulty, the management-information-record means stops additionally writing the disk-management information in the first management-information-record area, and additionally writes the disk-management information in the second management-information-record area.