| 摘要 |
PURPOSE:To record and reproduce two faces of a disk without turning over by facing disks on which spiral tracks different in the direction of winding of spiral, and bonding plural disks together. CONSTITUTION:Spiral tracks 7, 8 different in the direction of winding are formed on the opposing disk faces 5, 6 of disks 2, 3. The spiral track 7 of the disk face 5 is recessed and a spiral track 8 of the disk face 6 is projected. When mounted to a spindle, the directions of turning of spiral of tracks 7, 8 become equal when looked from a laser light source. Thus, recording and reproducing can be made on disk faces 5, 6 without turning over an optical disk 1. |
