| 摘要 |
PURPOSE:To reduce face runout of a disc and the burden on the electric circuit system, of an objective lens driver by using a centrifugal force produced from high speed revolutions, and enhancing the hold of the disc with a turn table and a clamp cup. CONSTITUTION:When a current flows to a motor 2 and a motor shaft starts rotation, a spindle stand 4 also rotates, each weight 19 fitted to the stand 4 via a plate spring 16 receives a centrifugal force and is moved far from the rotation center shaft of the stand 4. A notch taper section 19a of each weight 19 contacts a taper 13a of an opening 13 provided for the clamp cup 12 not contacted at standstill and when the rotation of the stand 4 is further increased, the centrifugal force is enhanced to press the said taper 13a outside. When the taper 13a is pressed, a force moved to the turn table 8 is exerted or the clamp cut 12 and a force holding the disc 10 from the upper and lower part is further enhanced at rotation. |
