| 摘要 |
PURPOSE:To smooth the surface of a disc and to reproduce disc information effectively by providing a member to rotate together with a disc with a supporting point for rotation and fitting disc pressing plates to press a disc to a turn table by the suction force of a magnet when putting the disc on the turn table. CONSTITUTION:The disc pressing plate 30 is made of a magnetic material and pivotally supported to a supporting part 31 projected upwards from a boss 18, its intermediate part is penetrated into a window hole 33 of a center cap 20 and its leading end is abutted to the upper surface of the disc 1. The pressing plate 30 is sucked by the magnet 34 fixed on the upper surface of a magnet base 16 to press and hold the disc 1 by a disc pressing part 30a at the leading end part. These pressing plates 30 are arranged on left and right positions about the center of rotation or three points of a regular triangle and their pressing force is uniformed. Thus, the surface of the disc is smoothed and effective reproduced signals can be obtained by fitting these pressing plates 30 even if the disc is slightly distorted. |
