| 摘要 |
PURPOSE:To prevent wear and damage of a disc and a magnetic head and improve the reliability for recording and reproducing by providing a stylus with a metallic piece to detect variation of the capacity between the stylus and the disc and servo-controlling floating of the stylus. CONSTITUTION:A stylus 7 is provided with a metallic piece 40, and variation of the capacity between the metallic piece 40 and the disc which is proportional to variation of a floating quantity (b) of the stylus is detected by a capacity variation detecting circuit 10. This detection output is converted to a servo error signal by an error detecting circuit 11 to control a stylus actuator 9 through drivers 41 and 12, and floating of the stylus 7 is servocontrolled, and a floating quantity (h) is always constant. Consequently, the stylus and the disc are not brought into contact with each other to prevent wear and damage of the disc and the magnetic head, and the reliability for recording and reproducing is improved by steady floating. |
