| 摘要 |
PURPOSE:To attain the tracking with high accuracy and a large allowable eccentric degree by detecting the position of an optical pickup unit via an electromagnet and an electromagnetic position sensor and at the same time shifting the pickup unit until it is adsorbed by the electromagnet by a linear motor. CONSTITUTION:A carriage 10 contains an electromagnet 17 forming an oscillating motion holding mechanism and a electromagnetic position sensor 24 set opposite to each other centering on an optical pickup unit PU15. The position of the PU15, i.e., the gap between a magnetic plate 15b and the electromagnet 17 is detected by the electromagnet 17 and the sensor 24. At the same time, the PU15 is shifted by a linear motor 11 until the PU15 is adsorbed by the electromagnet 17. The driving of the motor 11 is controlled so that the moving speed of the arm 15 is lowered as the gap is gradually reduced. Thus the PU15 has a slow collision against the electromagnet 17, and the PU15 is adsorbed and held simultaneously with collision. Thus it is possible to attain the tracking with high accuracy and a large allowable eccentric degree. |
