Hitachi, Ltd.

Eiji Ashida

Moriaki Fuyama

Shinji Narishige

Makoto Morijiri

Hiroshi Fukui

Hiroshi Ikeda

Takashi Kawabe

Hideo Tanabe

Isamu Yuito

Takao Imagawa

Tetsuo Kobayashi

Susumu Soeya

Shigeru Tadokoro

Tadayuki Iwakura

Hiroaki Koyanagi

Tetsuya Okai

Saburo Suzuki

Satoshi Kokura

Masayasu Nihei

Yoshiki Hagiwara

Akira Onuma

Shunichiro Kuwatsuka

Masatoshi Tsuchiya

Haruko Tanaka

Akira Taniyama

Makoto Saito

Yutaka Sugita

Masanobu Hanazono

Kouichi Nishioka

Yokuo Saitoh

Akira Sato

Masayasu Fujisawa

Issei Takemoto

Yuzo Kozono

Harunobu Saito

Xudong Zhang

Makoto Aihara

Hideki Yamazaki

Masayuki Takagi

Hiroshi Wachi

Shinichi Hara

Yoshikazu Tsuji

Yasuo Wakaki

Masaya Okada

Yusuke Anma

Eimi Ando

Shoh Tarasawa

Ataru Kobayashi

The present invention provides a method of manufacturing a core shroud for a nuclear plant and a nuclear power plant structure in which a groove portion is easily assembled in the case of manufacturing the core shroud having a weld structure of a nuclear power plant by a laser welding, and it is possible to obtain a weld joint portion in which a plastic distortion region and a residual stress are as small as possible, going with a solidification shrinkage of the weld portion. At a time of welding butted portions of a plurality of members constructing a core shroud, a root face is provided in the butted portion, a length of the root face is set to 25% to 95% of a thickness of the thinner one of the butted portions of a plurality of members, a narrow groove is provided in the other than the root face, and the butted portions are welded by a laser welding using a weld wire.

Method of manufacturing core shroud for nuclear power plant and structure of nuclear power plant

A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by the patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks.

Method of fabricating a magnetoresistive thin-film magnetic head

A magnetic domain controlling film for controlling the magnetic domain of a magnetoresistive film is formed by a patterning technique on a lower insulating film formed on a lower shield film. The magnetoresistive film is formed on the magnetic domain controlling film for converting a magnetic signal from a magnetic recording medium into an electrical signal using the magnetoresistive effect. A resist pattern is formed by the lift-off method on the magnetoresistive film in such a fashion as to leave a region of the magnetoresistive film corresponding to the tracks of the magnetic recording medium. A magnetoresistive element is formed by ion milling leaving only the portion of the magnetoresistive film corresponding to the tracks. An insulating layer is formed on the resist pattern, on the upper surface region of the lower insulating film other than the portion thereof right under the magnetic domain controlling film reduced in thickness by ion milling, and on the upper surface region of the magnetic domain controlling film other than the portion thereof right under the magnetoresistive film. An electrode film is formed on the insulating layer, after which the resist pattern is removed. The insulating layer is contiguously deposited on the upper surface region formed in a thin layer of the lower insulating film and on a part of the upper surface region formed in a thin layer of the magnetic domain controlling film.

Magnetoresistive thin-film magnetic head and method of fabrication

A thin film magnetic head comprising a sintered ceramic substrate, an underlayer, a bottom magnetic core film, a magnetic gap film, an insulating film containing coil windings, a top magnetic core film, and a protective layer. The substrate and other films and layers form an air bearing surface. The under layer, the magnetic gap film and the protective layer comprise Al.sub.2 O.sub.3, and the bottom and the top magnetic core films comprise Ni--Fe alloy. This structure gives substantially the same etching rate, when the air bearing surface is polished using a working fluid of pH 6-8, for any of the substrate, the films comprising Al.sub.2 O.sub.3 and metal oxide described above, and the films of Ni--Fe alloy. Thus, steps (pole top recessions) on the air bearing surface can be made as small as 0.015 .mu.m or less. Accordingly, the magnetic head can be held in a stable attitude, thus obtaining good recording characteristics.

Thin film magnetic head and production method thereof and magnetic disk

A magnetic disc apparatus is disclosed, in which a magneto-resistance effect film converts a magnetic signal into an electrical signal by use of the magneto-resistance effect, a pair of electrodes supplies a signal detection current to the magneto-resistance effect film, and a magnetic domain control layer controls the magnetic domain of the magneto-resistance effect film. The magneto-resistance effect film, the electrodes and the magnetic domain control layer constitute a magnetic head of magneto-resistance effect type. An isolation film is formed in a magneto-sensitive portion of the magneto-resistance effect film between the magneto-resistance effect film and the magnetic domain control layer to break the magnetic coupling between the magneto-resistance effect film and the magnetic domain control layer.

Magnetic disc apparatus

A magnetoresistive head has a substrate (1) and, on the substrate, a magnetoresistive film (40) for converting a magnetic signal into an electric signal by using magnetoresistance effects and a pair of electrodes (60) for causing a signal detection current to flow through the magnetoresistive film. A pair of first domain wall suppressing layers (30) are arranged at opposite end portions of the magnetoresistive film, respectively, to apply a longitudinal magnetic bias to the magnetoresistive film. A second domain wall suppressing layer (45) is also provided for applying a longitudinal magnetic bias, which is weaker compared with the longitudinal magnetic bias applied by the first domain wall suppressing layers, to the magnetoresistive film (40).

Magnetoresistive head

A method of fabricating a thin-film magnetic in which a mask pattern in etching a bottom pole is formed of first and second mask films in this order when viewed from the bottom pole, the first mask film is used for defining, by self-alignment, the length of that portion of the side edge of a top pole which is nearly perpendicular to a magnetic gap, the second mask film makes it possible to etch the bottom pole with high dimensional accuracy, a non-magnetic film is formed on the mask pattern having the bottom pole thereunder and the exposed region of a substrate, and the top pole is formed after the mask pattern has been exposed and removed.

Method of fabricating thin-film magnetic head

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

A method of forming a thin film pattern on a base having a step portion. This method comprises a first step of forming a thin film of given material on the base, a second step of forming a predetermined pattern of a first photoresist film on said thin film at one of a first portion including a lower part of the step portion and a second portion including an upper part of the step portion, a third step of forming a predetermined pattern of a second photoresist film on said thin film at the other of the first and second portions and a fourth step of applying ion-milling to said thin film of given material using masks said first and second photoresist film patterns formed on said thin film at the first and second portions.

Method for forming thin film pattern and method for fabricating thin

In a welding apparatus having a plurality of electrodes and adapted for carrying out welding operation on a workpiece by alternately supplying currents to the individual electrodes through switching elements, an apparatus and method of controlling the currents supplied to the electrodes, comprising selecting the values of the currents supplied to the individual electrodes depending on the material of the workpiece, and carrying out the welding operation on the workpiece by alternately supplying the currents of the selected values to the individual electrodes respectively through the switching elements. The method is featured by the fact that the ratio between the individual currents is selected under the condition that the sum of the values of all the currents is maintained at a predetermined value. It is also featured by the fact that, depending on the welding condition, the values of the individual currents can be freely selected without the limitation of maintaining the sum of all the currents at the predetermined value. Therefore, the apparatus and method are applicable to welding of a variety of materials by selecting the values of the individual currents depending on whether the workpiece has a high or low melting point and also whether the workpiece has a high or low heat conductivity.

Method of electrode current control in welding apparatus having a

Disclosed is a method and apparatus for automatically controlling arc welding, wherein pieces of optical information provided by at least two bands of different wavelengths of light radiated from a weld area being arc-welded under predetermined welding conditions are alternately picked up by an optical device to extract various weld factors representing the actual status of the weld area from these pieces of optical information, and the extracted weld factors representing the actual status of the weld area are compared with the desired values of the weld factors representing the desired status of the weld area to compute the error or errors of the welding conditions, so that the welding conditions can be corrected on the basis of the detected error or errors of the welding conditions, whereby the weld factors can be controlled to the desired values.

Method and apparatus for automatically controlling arc welding

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Hitachiota, Japan

Eiji Ashida