| 摘要 |
A recording disc (10, 18) is provided by a disc-shaped, formed-sheet-metal support (18) across which a flexible recording sheet (10) is stretched. The formed-sheet-metal support (18) has a central spindle opening (30) which can be precisely centered by simultaneously punching the spindle opening (30) and the circular periphery, thus permitting hight-speed rotation of the recording disc (10. 18) in use. |
