Hitachi, Ltd.

Hitachi Const. Mach. Company

Kanji Kawakami

Motohisa Nishihara

Hideo Sato

Satoshi Shimada

Kazuji Yamada

Masanori Tanabe

Hiroshi Fukui

Yutaka Sugita

Shigeyuki Kobori

Kazuo Kato

Takao Sasayama

Minoru Takahashi

Shinji Narishige

Seiko Suzuki

Tetsuo Kobayashi

Yokuo Saitoh

Moriaki Fuyama

Masaaki Hayashi

Yoshinori Takeuchi

Takayoshi Ohtsu

Yuzo Yamaguchi

Kazuo Nakagoshi

Hiroaki Hachino

Hirotsugu Fukuoka

Katsuya Mitsuoka

Hiroshi Daito

Katsuyuki Tanaka

Makoto Aihara

Hitoshi Minorikawa

Tetsuo Masukawa

Ryosaku Kanzawa

Fumitaka Muranushi

Mitsuo Suda

Yutaka Kobayashi

Hiroshi Sasaki

Hiroshi Kimura

Hiroshi Ikeda

Takahiro Yamada

Yoshihiro Shiroishi

Kunio Miyashita

Kaoru Uchiyama

Ryoichi Kobayashi

Naoki Koyama

Kazuo Shiiki

Masahiro Kitada

Yasumasa Matsuda

Yoshio Sato

Isao Shimizu

Yoshikazu Hoshi

Tetsuo Ito

Takashi Kawabe

Hajime Aoi

Makoto Morijiri

Seikou Suzuki

Yutaka Misawa

Nobuyoshi Tsuboi

Hisao Okada

Masaharu Tadauchi

Norifumi Miyamoto

Hideki Nihei

Yoshihiro Hamakawa

Hiroshi Hayashida

Satoshi Suzuki

Hiroaki Koyanagi

Hideo Uzuhashi

Harunobu Saito

Syoji Sagae

Shunichiro Kuwatsuka

Toru Sugawara

Yukihiro Isono

Ichiya Sato

Masahide Suenaga

Takao Yoneyama

Masayuki Takagi

Takahiko Tanigami

Tadashi Imanaka

Tetsuo Doi

Soji Sasaki

Yoshikazu Tsuji

Sigeyuki Kobori

Yasuo Nagai

Yoshiakira Karakama

Eizi Ashida

Isamu Yuitoo

Osamu Hirai

Hisayasu Honma

Taisaku Kohzuma

Yukitaka Kitadate

Ken Murayama

Mareo Suto

Shigeru Inose

Kouji Takeshita

Yamagata, Deceased, Koji

By Tetsuji Yamagata, Legal Representative

By Reiko Yamagata, Legal Representative

In an inductive-write, magnetoresistive-read type magnetic head having a magnetoresistive read head and an inductive write head superimposed on each other, the magnetic center of the read head is made more coincident with the physical center of the write head by a changing of a magnetization direction of a magnetoresistive element. The recording/reproducing apparatus using this magnetic head can thus have a good S/N ratio even if the track width is narrow.

Magnetic head and recording and reproducing apparatus having an

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 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

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 flying head slider has a slider body in which gas bearing rails are formed on a surface thereof disposed in opposed relation to a recording medium. A bleed portion is also provided at the surface of the slider body between a pair of gas bearing rails. The bleed portion is composed of at least a rectangular-shaped deep bleed portion in which the pair of longer sides thereof are directioned in parallel to the longitudinal axis direction of the gas bearing rails.

Flying head slider and method of producing 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

A flying head slider has gas bearing rails formed on a surface thereof disposed in opposed relation to a recording medium. The flying head slider flies at a microscopic distance above the recording medium by a pressure produced by a stream of gas resulted from the rotation of the recording medium. Each of the gas bearing rails comprises an inflow portion disposed at an inflow side of the gas stream so as to produce a pressure, an outflow portion disposed at an outflow side of the gas stream so as to produce a pressure, and a connective portion interconnecting the inflow portion and the outflow portion in a common plane. The connective portion serves to suppress an excessive compression of the gas, and achieves good damping characteristics.

Flying head slider and magnetic disk unit employing same

A compound magnetic head includes first and second magnetic poles arranged to face each other to define a recording gap therebetween, a magnetic film arranged between the first and second magnetic poles, a first non-magnetic film arranged between the first magnetic pole and the magnetic film to define a first reproducing gap therebetween, and a second non-magnetic film arranged between the second magnetic pole and the magnetic pole to define a second reproducing gap therebetween. The recording gap and the first and second reproducing gaps have the same width and a common center line of the gap widths parallel to the direction of movement of a magnetic recording medium.

Compound magnetic head having a recording head and a reproducing

In a thin-film magnetic head having a magnetic core (upper magnetic layer), in the electromagnetic conversion section, which are composed of an upper first magnetic film, inorganic insulating film, and an upper second magnetic film, the upper first magnetic film is used as a second wiring for electrical continuity between the coil and input/output terminal. The upper first magnetic film is connected to the center of a coil which is of a single-layer structure. The first upper magnetic film is made of a same material as the coil and is formed simultaneously with the latter. In the region in which an input/output terminal backing is formed, the upper first magnetic film of a second wiring is removed. Thus, the electrical continuity is established between the input/output terminal and the center of the coil. Also, the utilization of the upper first magnetic film as second wiring is applicable to a thin-film magnetic head having a coil of a multi-layer structure.

Thin-film magnetic head having special input/output terminal backing

DC bias currents are applied to a conducting wire of a thin film magnetic head to be inspected. When the DC bias currents (I.sub.0, I.sub.1, I.sub.2) are supplied to the conducting wire, the impedances (Z.sub.0, Z.sub.1, Z.sub.2) corresponding to the DC bias currents are measured. When a ratio (.vertline.Z.sub.1 -Z.sub.0 .vertline./.vertline.Z.sub.2 -Z.sub.0 .vertline.) corresponding to an overwrite characteristic (OW) reaches to a predetermined value by lapping tip portions of an upper magnetic layer and a lower magnetic layer of the magnetic head, the lapping process of the magnetic head is finished.

Method for making a thin film magnetic head

A film of a crystal - crystal phase transformation type optical recording alloy is formed on an insulating substrate. Information is erased from the alloy film by heating it with an expedient other than a laser beam. Information is read by sensing reflected light of light projected on the alloy film.

Optical information recording device

An image sensor comprises a transparent substrate, an optical lens formed integrally in one major surface of the transparent substrate, and a photosensor provided on the side of the other major surface of the transparent substrate and having output electrodes, wherein light incident on the optical lens is focussed by the lens onto the photosensor through the transparent substrate.

Image sensor

A method of making a silicon diaphragm pressure sensor includes forming an oxide film on one surface of a monocrystalline silicon substrate. A polycrystalline silicon layer is formed on the oxide film. The oxide film may be partly removed before the formation of the polycrystalline silicon layer. The polycrystalline silicon layer is heated and melt to recrystallize the same, thereby converting the polycrystalline silicon layer into a monocrystalline silicon layer. On the monocrystalline silicon layer may be epitaxially grown an additional monocrystalline silicon layer. By using the oxide film as an etching stopper, a predetermined portion of the substrate is etched over a range from the other surface of the substrate to the oxide film, thereby providing a diaphragm of the pressure sensor.

Method of making silicon diaphragm pressure sensor

A tablet type coordinate input apparatus comprises a flat medium for propagating a longitudinal elastic wave, longitudinal elastic wave detecting elements disposed on part of the end-adjacent side surfaces or of the front surface of the flat medium, a longitudinal elastic wave input member having an end portion terminating in a sharp-pointed end and brought into pressure engagement at that end with any desired position on the surface of the flat medium to radiate the longitudinal elastic wave from that end, an amplifier circuit amplifying electrical signals indicative of the elastic wave detected by the detecting elements, a comparator circuit comparing the signals amplified by the amplifier circuit with a predetermined threshold voltage thereby generating delay pulse signals corresponding to the propagation times of the longitudinal elastic wave, a counter circuit counting the lengths of time elapsed from the time of radiation of the longitudinal elastic wave toward the flat medium as a result of pressure engagement of the input member therewith to the time of generation of the delay pulse signals, and a computing circuit computing the coordinates on the basis of the time signals applied from the counter circuit.

Tablet type coordinate input apparatus using elastic wave

The drain voltage of an IGFET having a channel responsive to the change in physical quantity to be measured is negatively fed back to the gate terminal of the IGFET. The negative feedback loop includes series connection of a first amplifier having an amplification factor larger than unity and a second amplifier having an amplification factor smaller than unity. The interconnection point between the first and the second amplifiers is connected to the output terminal. There is provided a stable, highly sensitive and highly reliable semiconductor sensor.

Feedback circuit for a semiconductor active element sensor

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Mito, Japan

Kanji Kawakami