OBJECTIVE LENS DRIVING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an objective lens driving device in which a high-temp demagnetization is not generated and the enlarging of the size of a device is evaded by reducing the leakage magntice flux of an actuator to magnetic heads while enhancing the driving sensitivity of the actuator. SOLUTION: This device includes an objective lens 2, a lens holder 3 for holding the lens 2, a focusing coil 6 which is constituted integrally with the holder and is for displacing the holder 3 in a focusing direction vertical to the surface of a recording medium, a tracking coil which is constituted integrally with the holder 3 and is for displacing the holder 3 in a tracking direction which is parallel with the surface of the recording medium and also is in the radial direction and a magnetic circuit part 8 which applies a magnetic flux to the focusing coil 6 or the tracking coil and consists of one pair of magnets 10a, 10b in which different poles are disposed to face oppositely each other. The magnetic force of the latter arranged at a side nearer to the objective lens 2 between the one pair of magnets is set to become smaller than that of the former arranged at a side far from the lens.