Nippon Telegraph and Telephone Public Corporation

Hitachi, Ltd.

Fujitsu Corporation

Nippon Telegraph and Telephone Corporation

Yasunaga Mitsuya

Shigemitsu Oguchi

Hatsuo Takahashi

Ryoichi Arai

Wataru Hayakawa

Masayoshi Amasaka

Reizo Kaneko

Akio Mitamura

Tetsuo Mikazuki

Gen-ichi Ishida

Kunio Hoshiya

Kenji Kogure

Takao Kakizaki

Koji Otani

A head positioning system on a recording medium includes a recording medium having a periodic arrangement of data tracks and servo tracks wherein the periodic arrangement having a predetermined period includes N.sub.d (N.sub.d is an integer equal to or larger than 1) number of data tracks and N.sub.s (N.sub.s is an integer equal to or larger than 2) number of servo tracks, the servo tracks having single phase servo patterns, alternatively recorded thereon, a multi-head carrying a plurality of head elements disposed in a direction perpendicular to the tracks, so that the distance between head elements is (N.sub.h +1/M)P where N.sub.h is an integer equal to or larger than O, M is an integer equal to or larger than 2, and P is a track pitch, wherein the multi-head is movable in a direction generally perpendicular to the direction of the tracks, means for selecting a servo head for reading servo tracks and a data head for reading data tracks from the head elements during a seek operation, wherein a selected servo head is selected to reproduce a servo pattern from a servo track and a selected data head is determined based on the selected servo head, and wherein the multi-head is positioned on a servo track in every 1/M track pitch of movement.

Head positioning system for positioning a multiple head with respect to

A magnetic disc type memory device swinging actuator is constituted by a plurality of a driving assemblies juxtaposed on a stationary shaft and extending in the opposite direction. Each driving assembly include a head arm, a magnetic head mounted on one end of the head arm, a coil supporting member for supporting a flat coil and extending in the opposite direction to the head arm, and first and second permanent magnets spaced from the coil in an axial direction of the shaft and also spaced in a direction of arrangement of the flat coil. The first and second permanent magnets are magnetized in the axial direction of the shaft so that poles of opposite polarities confront the flat coil. The first and second permanent magnets are mounted on a common yoke and the flat coils are disposed in a closed magnetic flux path including the first and second permanent magnets and the yokes.

Swinging actuators for use in magnetic disc type memory devices

An improved ferro fluidic seal assembly having a cylindrical permanent magnet, a pair of ring-shaped yokes coupled coaxially with said magnet, and a fresh fluid storage containing ferro magnetic fluid mounted in a room defined by said magnet and yokes. Said fresh fluid storage is composed of a resilient elongated member like a stainless steel belt adapted and fixed in a circular shape along the surface of the magnet, and supplies fresh fluid to the clearance gaps defined between said yokes and a rotational body to seal said clearance gaps.

Ferro fluidic seal

At the start of operation, a floating magnetic head is brought into contact with the surface of a magnetic disk and the magnetic disk is then rotated to float the magnetic head off the magnetic disk surface. At the end of operation, the floating magnetic head is drawn away from the magnetic disk surface of the rotating magnetic disk and, after the lapse of a certain period of time, the magnetic disk is stopped. This prevents the floating magnetic head from sticking to the magnetic disk owing to dew condensation, permits easy miniaturization of the floating space and provides for increased recording density.

Air bearing head support

Growing community of inventors

Tokyo, Japan

Yasunaga Mitsuya