| 摘要 |
PURPOSE:To impress a bias magnetic field which is of a small constitution, little in a quantity of the power consumption and equal only to the necessary area by installing a coil for generating a bias magnetic field round the pick-up lens. CONSTITUTION:A coil 107b for generating a bias magnetic field is installed round an objective lens of the actuator 105 of the pick-up, and a bias magnetic field for recording and deleting to vertically-magnetized disk-shaped recording media occurs without using an electromagnet, etc., shifted by a large fixed coil or an exclusive-use shifting device. By the small and little power consumption constitution, the bias magnetic field can be impressed equally to the necessary area only. |
