Sony Corporation

Minnesota Mining and Manufacturing Company

Toshio Aizawa

Hideo Suyama

Kazuo Kurihara

Robert S Jackson

Yoshihisa Kawamura

Kietsu Iwabuchi

Zenkichi Nakamura

A geomagnetic direction sensor has a plurality of magnetic cores for converging terrestrial magnetism arranged circumferentially with pre-set gaps, and magneto-resistive effect devices in the gaps so as to lie substantially at right angles to the direction of the magnetic field in the gaps. The geomagnetic direction sensor has at least a pair of magneto-resistive effect devices lying substantially at right angles to each other. The magnetic core is formed of a magnetic material having soft magnetic properties. The current is supplied to the excitation coils placed around the magnetic core for applying a bias magnetic field to the magneto-resistive effect devices. Another set of magneto-resistive effect devices are connected in series with the magneto-resistive effect devices arranged within the gap so as to be substantially parallel to the direction of the magnetic field.

Geomagnetic direction sensor

Recording disk, such as a data recording disk, having:

Recording disk having improved centering hub and magnetic yoke

Method and apparatus for manufacturing a stretched surface recording disk wherein a laminate is formed by superposing magnetic sheets on upper and lower surfaces of a base with a bonding agent being interposed between the regions to be bonded, clamping both an outer annular portion and an inner annular portion of the resulting laminate, displacing the clamped inner annular portion including both magnetic sheets and the base relative to the clamped outer annular portion in a direction perpendicular to the surface of the base, thereby stretching the laminate and bonding the magnetic sheets to the base while the annular portions are so displaced.

Method and apparatus for manufacturing a magnetic recording disk

Growing community of inventors

Miyagi, Japan

Toshio Aizawa