OPTICAL DISK, OPTICAL DISK CARTRIDGE AND OPTICAL DISK UNIT

摘要

PROBLEM TO BE SOLVED: To provide an optical disk and an optical disk recording/reproducing device that have the ability, through one mechanism, of recording and reproducing of optical disks largely different in a recording region or a diameter size by holding the optical disk loaded on the mechanism by means of spindle motors corresponding to a plurality of reference faces and enable interchange. SOLUTION: In the optical disk unit that can record or reproduce a small diameter optical disk and a large diameter one having a much different size from the small one and that is equipped with a common optical pickup for both disks, there are oppositely arranged spindle motors intended respectively for the large and small diameter disks. In response to the operation in which one type of optical disk is loaded on the mechanism, one corresponding spindle motor moves to the holding position where the optical disk can be recorded or reproduced and holds the disk.