Oki Electric Industry Co., Ltd.

Katsushide Tanoshima

Masahiro Takahashi

Shizuo Nagata

Yasuo Shimizu

Minoru Ohtsuka

In an optical head apparatus for recording or reproducing information onto or from an optical disc, a carriage is movable along a guide shaft extending in a direction parallel with the radial direction of the optical disc, and an armature is mounted on the carriage so that it can rotate about a pivotal axis perpendicular to the surface of the optical disc. An objective lens is fixed to the armature and positioned to traverse the tracks on the optical disc when the armature rotates. Guide yokes extend in parallel with the guide shaft. Tracking and carriage-servo coils are fixed to the armature and have a hollow through which the guide yokes loosely extend. A magnetic field means creates magnetic lines of force perpendicular to the longitudinal direction of the guide yokes and parallel with the surface of the optical disc. A drive circuit supplies currents to the tracking and carriage-servo coils in such directions as to produce electromagnetic forces in parallel with each other thereby driving the armature along the guide yokes or in such directions as to produce electromagnetic forces in antiparallel with each other to rotate the armature about the pivotal axis.

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Tokyo, Japan

Katsushide Tanoshima