OBJECTIVE LENS DRIVE ASSEMBLY AND OPTICAL DISK DEVICE

摘要

PROBLEM TO BE SOLVED: To increase the effective length ratio of coils and to improve thrust by winding a focusing coil to nearly a rectangular cylindrical shape around an axis parallel with the optical axis of an objective lens so as to enclose an inner yoke and winding a tracking coil to a nearly rectangular cylindrical shape around an axis parallel with the radial direction of an optical disk so as to enclose the inner yoke. SOLUTION: A lens holder 2 is provided with the focusing coil 3 and the tracking coil 4 so as to enclose the circumference of the inner yoke 11. Permanent magnets 8 are mounted to face each other at outer yokes 9 so as to hold the focusing coil 3 and the tracking coil 4 in-between. The focusing coil 3 is wound around the axis parallel with the optical axis of the objective lens 1. The tracking coil 4 is wound around the axis parallel with the radial direction of the optical disk so as to come into contact with the central part on the flank of the focusing coil 3.