| 摘要 |
PROBLEM TO BE SOLVED: To easily transport software resources of different mediums by making outside diameters, track pitches and most shortest pit lengths of disks to be within prescribed ranges and performing recordings with respective prescribed formats. SOLUTION: The outside diameter of this optical disk is made to be 45mm-65mm and the recording of this disk is performed with the same capacity and the same format as those of a CD-ROM and a PD by forming a track pitch and the most shortest pit length or the most shortest recording length by the scale 45/120 to 65/120 being the scale at the time of comparing the diameters of this disk with 120mm being the outside diameter of a conventional CD-ROM and PD. When this disk is considered in the case of the CD-ROM, the track pitch becomes 0.60-0.87μm, the most shortest pit length becomes 0.310-0.520μm. For example, when the conventional CD-ROM having the outside diameter of 120mm, the track pitch of 41.6μm and the most shortest pit length of 0.828μm is to be recorded to the optical disk 100 having the outside diameter of 45mm, the track pitch, the most shortest pit length of this disk respectively become 1.6×45/120-0.60μm and 0.828×45/120=0.3105→0.310μm. |
