| 摘要 |
An optical disk medium and a drive system are provided that enable high density recording to be carried out. In the optical disk medium, recorded information tracks are formed in a concentric or spiral manner, and information is recorded and played back by irradiating the recorded information tracks with a laser beam through a transparent substrate or a transparent cover layer. A change in tilt of the optical disk medium over one circuit of each of the tracks is set equal to or less than an allowed value, a change in tilt over the entire surface of the optical disk medium is permitted to be larger than the allowed value, and low frequency bandwidth tilt control is carried out by the drive system.
|
