| 摘要 |
PURPOSE:To increase the effective recording area and also to increase the density of a recording track by forming a square spiral recording track in an effective recording area of a square optical recording card and rounding each corner of the spiral track. CONSTITUTION:An optical recording card 1 is read and reproduced by tracing an optical head of a single track over a recording track 3 from an initiation 5 or a termination 6 of the track 3 toward the other end side respectively. In this case, no dead space exists to an effective recording surface to improve the recording density since a square spiral recording track is formed in a square effective recording area 2 and along the inner circumference of the area 2. Furthermore the generation of vibrations that give the evil effects to the recording and reading since each corner of the spiral track is rounded. In addition, such a trouble where the adjacent tracks are lost can be solved. |
