| 摘要 |
PURPOSE:To decrease the temp. difference between both surfaces of a disk and to lessen the warpage of the disk by forming a suitable number of through- holes on the peripheral side more inside a data area. CONSTITUTION:The disk 21 has a hub 22 which is the center of rotation and is coated with a recording film 23 of a prescribed width in the outer peripheral part, to form the part as the data area 24. A suitable number of the through- holes 25 are formed concentrically around the hub 22 at prescribed intervals on the inner peripheral side of the data area 24. The heat applied on one side of the disk is passed to the opposite side surface thereof by the through-holes 2 to decrease the temp. difference between the front and rear surfaces of the disk and to suppress the temp. rise of the rear surface. |
