Abstract: A method for phase matching matches a relative phase of a first element and a second element by detecting a magnetic flux. The method provides a magnetic flux generator to generate the magnetic flux. The method also provides a magnetic sensor in order to detect the magnetic flux. According to the magnetic flux detected by the magnetic sensor, the relative position of the first element and the second element is adjusted until the magnetic flux reaches a predetermined value, which means that the phase of the first element and that of the second element are matched.

Abstract: The present invention provides a shock prevention device for use in a disc-reading device. The shock prevention device includes a damper for reducing the vibration generated by a rotation motor and a compression device for compressing the damper. When the rotation motor rotates at a high speed, the compression device does not compress the damper to reduce the transmission of the high-frequency vibration. When the rotation motor rotates at a low speed, the compression device compresses the damper to prevent the amplification of the low-frequency vibration.

Abstract: A method for phase matching matches a relative phase of a first element and a second element by detecting a magnetic flux. The method provides a magnetic flux generator to generate the magnetic flux. The method also provides a magnetic sensor in order to detect the magnetic flux. According to the magnetic flux detected by the magnetic sensor, the relative position of the first element and the second element is adjusted until the magnetic flux reaches a predetermined value, which means that the phase of the first element and that of the second element are matched.