Hitachi, Ltd.

Masayuki Abe

Junichi Ikoma

Atsushi Ichikawa

Akio Yabe

Hideo Onuki

Yuji Fujihira

Kenzi Abiko

Shigefumi Hida

Disclosed is a device for driving an objective lens of an optical disk apparatus in both the tracking direction and the focusing direction. The device comprises a rocker arm supported rotatably and axially slidably by a supporting shaft and carrying the objective lens on its front end, a pair of first coils disposed on both sides respectively of an end on rear end of the rocker arm remote from the front end carrying the objective lens for driving the objective lens in the tracking direction, and a second coil mounted to the lower surface of the rocker arm for driving the objective lens in the focusing direction. A pair of magnets for producing a magnetic field for driving the objective lens in the focusing direction and a magnetic field for driving the objective lens in the tracking direction are mounted to a pair of yokes erected on both sides of the supporting shaft respectively. Current is supplied to the first coils to produce moments of rotation rotating the rocker arm thereby driving the objective lens in the tracking direction, and current is supplied to the second coil to move the rocker arm in the axial direction of the supporting shaft thereby driving the objective lens in the focusing direction.

Objective lens driving device

A disc positioning device for positioning a disc having a center opening with respect to a spindle for driving the disc for rotation by bringing the center axes thereof into alignment with each other. An adapter in the form of a hemispherical body of a diameter greater than that of the center opening of the disc is mounted on the spindle in such a manner that the center of a spherical body from which the hemispherical body of the adapter is severed coincides with the center axis of the spindle at all times. The adapter is urged by a spring to be biased with the center thereof serving as the center of rotation.

Disc positioning device

A yoke adapted for use with a wide deflection angle picture tube used in a television receiver set is disclosed, in which a horizontal yoke is of saddle-shape and a fringe thereof is of non-circular shape so that a raster scanned on the picture tube shows no vertical pincushion distortion.

Deflection yoke for use with wide angle deflection system

Growing community of inventors

Yokohama, Japan

Masayuki Abe