Victor Company of Japan, Limited

Hitachi Koki Co., Ltd.

Kazuo Kimura

Noboru Watanabe

Yasuo Ishizaka

Eiichiro Imaoka

Shinichi Sakamoto

Yukinori Taneda

Shun Suzuki

Kunihide Sakai

Shinichi Tsuyuki

Yasuhiro Ayabe

Chikara Inoue

Toyoaki Takayasu

Hiroyuki Hayashi

Kayoko Miyake

Yoshio Hashimoto

A perpendicular magnetic recording medium comprises a recording medium base, a lower layer formed on the recording medium base, and an upper layer formed on the lower layer. The lower layer is made of a first material including cobalt, chromium and one or more elements other than cobalt and chromium. On the other hand, the upper layer is made of a second material including cobalt, chromium and one or more elements other than cobalt and chromium. A quantity of the one or more elements added to cobalt and chromium making up the second material is less than a quantity of the one or more elements added to cobalt and chromium making up the first material.

Perpendicular magnetic recording medium

A perpendicular magnetic recording medium comprises a recording medium base, a lower layer formed on the recording medium base, and an upper layer formed on the lower layer. The upper layer is made of cobalt-chromium, and the lower layer at least includes cobalt and chromium.

A perpendicular magnetic recording and reproducing system records and reproduces a signal on and from a perpendicular magnetic recording medium comprising a magnetic layer which is made from one magnetic material and is constituted by a layer having a low coercivity and a layer having a high coercivity on top of the layer having the low coercivity, by use of a ring core head and utilizes the layer having the low coercivity as a high permeability layer and the layer having the high coercivity as a perpendicular magnetization layer.

Perpendicular magnetic recording and reproducing system

A perpendicular magnetic recording medium comprises a recording medium base, a low coercivity layer formed on the recording medium base and having a low coercivity in an in-plane direction thereof, and a high coercivity layer formed on the low coercivity layer and having a high coercivity in a direction perpendicular to a surface of the low coercivity layer. The low coercivity layer and the high coercivity layer are formed from the same magnetic material and constitute a magnetic layer. A method of manufacturing this perpendicular magnetic recording medium comprises a single magnetic layer forming process of successively and continuously forming the low coercivity layer and the high coercivity layer on the recording medium base by using the same magnetic material as a depositing material.

Perpendicular magnetic recording medium and manufacturing method thereof

A magnetic head for tape recording and/or reproducing is composed of a pair of abutting thin magnetic metal cores with front and back gaps therebetween, and a pair of magnetic oxide cores sandwiching each of the magnetic metal cores therebetween. The magnetic oxide cores include bodies of glass disposed adjacent the front gap and sandwiching each magnetic metal core to allow the front gap to be visually checked for its depth. To fabricate such a magnetic head, magnetic oxide cores are bonded to a thin magnetic metal core, and the bonded block is cut off across the magnetic metal core to form two block pieces. Each of the block pieces is provided with bodies of glass in recesses formed in a cut surface thereof. After the cut surfaces have been ground, the block pieces are bonded with the cut surfaces confronting each other while keeping the magnetic metal cores in alignment. The bonded block pieces are cut off along the aligned magnetic metal cores into a magnetic head blank, which is then ground to provide a tape-contacting surface.

Magnetic head and method of making the same

An electric wire is wound as coil turns in slots in electric rotating machinery component such as a stator or an armature. The wire as it is supplied from a nozzle or flyer is guided by movable formers into successive layers of coil turns in the slots without forming an unwanted dead space in the slots. The formers are moved in radial increments to provide successive spaces in the slots for allowing the successive coil turn layers to be neatly laid in the spaces.

Growing community of inventors

Yokohama, Japan

Kazuo Kimura