| 摘要 |
PURPOSE:To perform recording with high density by forming a hole part which opens toward the center of a disk to a jacket at both sides of a head inserting hole of the jacket and at a place near the outer edge of the disk put into the jacket. CONSTITUTION:The hollow parts 28 are formed on the observe and reserve sides of a jacket 8 at both sides of a head inserting hole 25 and near the outer edge of an inside disk 9. This part 28 opens toward the center of the disk 9. For this part 28, a cut 29 is given to the jacket 8 and the outer side of the jacket is pressed in a hemispherical form 30 to form a hole part 31. An air current 32 is discharged through the part 31 in response to the revolutions of the disk 9. Then the part 28 is pushed down and touches the counter sheet. Thus the sheet on the observe and reserve sides of the jacket 8 are kept at a fixed distance equivalent to the total thickness of the part 28 and an interliner 2. |
