| 摘要 |
PURPOSE:To prevent a surface A and a surface B from reversely rotating to each other with respect to an optical head so as to eliminate the deterioration of a surface recording density by forming tracks generated on respective signal recording surfaces in a inverse-spiral form. CONSTITUTION:The optical disk 1 is composed of the surface A and the surface B, and the spiral tracks are preformatted. The spiral tracks in opposite directions are generated on the surface A and the surface B. Thus, reproducing signals from the surface A and the surface B are reproduced in the order of a1, a2 and a3 by forming the spiral tracks in the opposite directions which are generated on the front and back surfaces of the optical disk 1, and the signals can normally be read and recorded in a movable optical part. Thus, the signals can be recorded and reproduced in the spiral tracks of the surface A and the surface B on the disk 1 by two facing optical heads, and the deterioration of the surface recording density is eliminated. |
