Hitachi, Ltd.

Hitachi Maxell, Limited

Hitachi Cable, Inc.

Nippon Telegraph and Telephone Public Corporation

Hitachi Microcomputer Engineering, Ltd.

Yutaka Sugita

Ryo Suzuki

Teruaki Takeuchi

Masatoshi Takeshita

Naoki Kodama

Tadashi Ikeda

Norio Ohta

Ryo Imura

Hiroshi Umezaki

Shinji Narishige

Hiroyuki Minemura

Hiroshi Fukui

Tatsuya Sugita

Yoshio Sato

Nobuyoshi Tsuboi

Yokuo Saitoh

Isao Ikuta

Hisashi Andoh

Yoshihito Maeda

Masaichi Nagai

Keikichi Ando

Yuzuru Hosoe

Moriaki Fuyama

Kanji Kawakami

Katsuya Mitsuoka

Toshihiro Sato

Noriyuki Kumasaka

Masaaki Hayashi

Naoki Koyama

Takashi Kawabe

Toshio Niihara

Shinji Takayama

Norikazu Tsumita

Hideki Nishida

Hiroshi Ikeda

Hiroyoshi Matsumura

Shigekazu Otomo

Hajime Aoi

Makoto Morijiri

Takashi Toyooka

Tetsuo Kobayashi

Tsuneo Suganuma

Kazuo Nakagoshi

Hirotsugu Fukuoka

Masanori Tanabe

Kazuyuki Nagatsuma

Nagatugu Koiso

Makoto Aihara

Hirozi Yamada

Shunichiro Kuwatsuka

Makoto Saito

Akio Takahashi

Atsushi Saito

Kazuo Shigematsu

Yoshihiro Shiroishi

Akio Mukoh

Hideo Fujiwara

Kazuji Yamada

Fumiyoshi Kirino

Hiroaki Miwa

Tadahiko Miyoshi

Keikichi Andoo

Ryoichi Sudo

Takao Imagawa

Fumiyuki Kobayashi

Satoru Ogihara

Shinkichi Horigome

Takayoshi Ohtsu

Hirokazu Aoki

Toshio Katsuyama

Yoshinori Miyamura

Reiko Arai

Masanobu Hanazono

Tetsuo Tajima

Shunichi Numata

Kouichi Nishioka

Kunio Miyazaki

Takuji Ogawa

Hirokazu Inoue

Minoru Hiroshima

Tadayuki Iwakura

Yosuke Seo

Masaaki Sano

Jun Naruse

Shigeru Yoshizawa

Tetsuya Okai

Kazutoshi Yoshida

Osamu Miura

Nobuo Saito

Takashi Tamura

Eiji Ashida

Shigenori Okamine

Yooji Maruyama

Akira Onuma

Masatoshi Tsuchiya

Youji Maruyama

Hideki Yamazaki

Masayuki Katsumoto

Kazuhiro Ishida

Toshihiro Yoshida

A magnetic disc apparatus has a large recording density of 120 megabits per square inch or more, and defines a relationship among a pole thickness (Pt) of thin-film magnetic heads disposed in the magnetic disc apparatus, and a saturation flux density (Bs) of cores of the heads and a recording wavelength (.lambda.) for the thin film magnetic discs have a coercivity of 1800 Oe or more, wherein a levitation space between the head and the disc is 0.15 .mu.m or less.

Large capacity magnetic disc apparatus with a particular relationship

A magnetic lamination including at least a first magnetic film, a second magnetic film and, a third magnetic film, a first intervening intermediate film intervening between the first and second magnetic films, and a second intervening intermediate film intervening between the second and third magnetic films, wherein the respective magnetic films each comprise a magnetically soft film, the first and second intervening films differ in thickness, and one of the first and second intervening films can have a zero thickness and further, the intervening intermediate film can include a transition metal and a substance which is likely to form a heterogeneous mixture with the transition metal.

Magnetic heads and magnetic recording reproducing devices using magnetic

An optical information handling device in which reflectivity of the conventional reproduction-only type optical disk is lowered to 60% or less and is made equal to the reflectivity of write-once type and rewritable type optical disks, whereby interchangeability in these of these disks is possible.

ROM type optical recording medium with a high reflectivity and an

A magnetic recording device includes a magnetic disk for storing information, a magnetic head for writing and reading information relative to the magnetic disk, a device for rotating the magnetic disk relative to the magnetic head in such a manner that speed of said magnetic disk relative to the magnetic head is 6 to 40 m/s at an innermost track of the magnetic disk, and a device for applying a load to the magnetic head so that a gap between the magnetic disk and the magnetic head disposed in opposed relation to the magnetic disk can be kept to not more than 0.1 .mu.m.

Magnetic recording apparatus with magnetic head on slider having applied

The information processor uses a portable memory formed on a transparent substrate which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium rotatably incorporated within a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through the case which has at least a transparent light-incident portion. The case includes therein a rotation means for rotating the recording medium within the case, thereby enabling even further reduction in size of the information processor.

Optical disk memory and information processing apparatus

The invention relates to an optical memory in which an optical recording medium is built in a case, and also to a memory apparatus. Recording, reproducing and erasing operations are performed by irradiating light via a transparent portion of the case onto the built-in optical recording medium. The optical recording medium built in the case has face vibrations with respect to the case, because it is moved within the case. The present invention is characterized by employing such a construction for optically mitigating irregular fluctuation in reflectivity caused by this face vibration. In the optical memory of the present invention, the reflectivity fluctuation caused by an interference effect made between reflection light from the case and air, and also reflection light from the optical recording medium and air due to the relative deviation in the face vibrations, may be reduced by antireflection films provided in the case and the optical recording medium. In a memory apparatus of the present invention, the abovedescribed memory is mounted, the fluctuation in the reflectivity is monitored and laser power is varied in order to further mitigate the reflection vibrations.

Optical memory and information processing apparatus

An LSI mounting substrate having a multilayered thin film wiring portion, with the thin film wiring portion being divided into wiring units each composed of a plurality of wiring layers, with the wirings between the units being electrically connected through connecting pads defined in the same surface as that of a surface conductive layer of the unit.

Mounting substrate

There is provided a compact and thin optical disk unit as a memory unit suitable for a portable computer such as a book type computer and a portable recording/reproducing apparatus. In the optical disk unit, the diameter of an objective lens is limited and a beam shaping prism, a beam splitter, a mirror and a 1/4 wavelength plate are formed into a unitary structure to make easy the optical axis adjustment of an optical head and ensure highly accurate assembling.

Information processing apparatus and optical head incorporated therein

A thin film magnetic head comprising a substrate on which are successively formed a base layer, a lower magnetic film, a gap layer, an insulator layer, a conductor coil, an upper magnetic film, and a first mask, is manufactured by a method in which one or more of a gas which can be expressed by the general formula of CnHxFy (where n.gtoreq.1, x+y=2n+2, x&gt;0, y&gt;0, and x.gtoreq.y); and a gas which can be expressed by the general formula of CnHxFy (where n.gtoreq.1, x+y=2n+2, x.gtoreq.0, y.gtoreq.0, and x&lt;y) is used. The structure of the magnetic head thus obtained is such that, at a height near the interface between the mask and the upper magnetic film provided therebelow, the angle defined by the side edge surfaces of the mask and the above-mentioned interface ranges from 75.degree. to 90.degree..

Thin film magnetic head and method of manufacturing the same

A magnetic recording apparatus for recording information on a magnetic recording medium. A circuit for generates a recording current pulse train and supplies the pulse train to a magnetic head. The last pulse of the recording current pulse train dampled waveform. A ripple current is superposed on the damped waveform.

Magnetic recording apparatus

A magnetic disc apparatus includes a magnetic disc for recording information; a thin film magnetic head including a magnetic pole structure having an upper magnetic pole tip and a lower magnetic pole tip arranged to provide a magnetic gap at respective end portions thereof for writing and reading information in and from the magnetic disc; a device for rotating the magnetic disc; and a device for positioning the thin film magnetic head; the upper and lower magnetic pole tips having different contours at the respective end portions as viewed from a side confronting the magnetic disc wherein the difference (.DELTA.CW in .mu.m) in the width, along the magnetic gap, of the upper magnetic pole tip and the width, along the magnetic gap, of the lower magnetic pole tip satisfies the relation

Magnetic disc apparatus with thin film head suitable for high-density

The information processor uses a portable memory which is able to be overwritten by laser power modulation system. The memory includes a disk type recording medium incorporated rotatably in a thin case, and carries out write/read/erase by means of a first magnetic field application device, a second magnetic field application device, and an optical head radiating light through this case.

Information processor and disk memory used in the same

A magnetic head for reading from and/or writing to a magnetic information storage medium has a substrate on which a plurality of thin films are formed in sequence. The films provide a magnetic circuit having a magnetic gap, a bottom pole piece and a top pole piece overlying said bottom pole piece. The top pole piece is formed as a tip portion adjoining the magnetic gap and a rear portion which makes magnetic contact with the tip portion. The rear portion is formed in the sequence after the tip portion. To ensure accurate thickness and width of the tip portion, a non-magnetic protective film is formed on the tip portion after the tip portion is formed and before the rear portion is formed.

Magnetic information storage apparatus including magnetic head and

This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formula

Magnetic disk device and method of recording/retrieving information

A thin film magnetic head has magnetic films, at least one of which is composed of a material containing major components of nickel and iron and one or more element from nitrogen, oxygen and carbon and has two of face-centered cubic system and body-centered tetragonal system, whereby thin film magnetic heads having a high permeability and low coercive force can be provided.

Thin film magnetic head with mixed crystal structures

Growing community of inventors

Tokorozawa, Japan

Yutaka Sugita