Matsushita Electric Industrial Co., Ltd.

Hitachi Metals, Ltd.

Jibu Electric Co., Ltd.

Yuji Nagata

Toshio Fukazawa

Satoru Mitani

Kumiko Wada

Yoshihiro Tosaki

Kazuo Nakamura

Daichi Azuma

Hidetsugu Kawabata

Terumi Yanagi

Keizo Ishiwatari

Kengo Takahashi

Yoshihiro Tozaki

Toshio Shimizu

The present invention provides an Fe-based amorphous transformer magnetic core formed by stacking Fe-based amorphous alloy thin strips and satisfying the following (1) to (3) in a direct current B-H curve measured by applying a magnetic field of 80 A/m to the magnetic core:B80&#x2267;1.1 T&#x2003;&#x2003;(1)0.5 T&#x2266;Br&#x2266;0.7 T&#x2003;&#x2003;(2)B80&#x2212;Br&#x2267;0.6 T&#x2003;&#x2003;(3)wherein B80 represents a magnetic flux density (T) obtained when magnetization is performed in the magnetic field of 80 A/m, and Br represents a residual magnetic flux density (T) obtained when a magnetic field is changed to 0 A/m after magnetization is performed in a magnetic field of 80 A/m.

Fe-based amorphous transformer magnetic core, production method therefor, and transformer

A hard magnetic thin film magnetized in one direction is disposed on or in the vicinity of a magneto-resistive element upon which inclined electrodes are formed. A magnetic field from the hard magnetic film magnetizes the magneto-resistive element stably so that the element has a single magnetic domain. Thus, the magneto-resistive head is remarkably stable with respect to the disturbance magnetic field and inhibits Barkhausen noise from being produced. As a result, the magneto-resistive head reproduces stably and with an improved S/N ratio.

Magneto-resistive head including a film of hard magnetic material

In a magnetoresistive head capable of performing favorable magnetic recording and reproduction, an overlap width of a front yoke and a magnetoresistive element is always wider than an overlap width of a back yoke and the magnetoresistive element. Generally, the magnetoresistive head varies in its reproduction efficiency by the overlap width of the yoke and magnetoresistive element. In particular, the reproduction output is significantly affected by the overlap width of the front yoke and magnetoresistive element, and when the overlap width of the front yoke becomes narrower than the overlap width of the back yoke, the reproduction output tends to decrease abruptly. Therefore, by keeping the overlap width of the front yoke always wider than the other, a stable reproduction output can be achieved. In particular, an outstanding effect is obtained in a multi-channel magnetoresistive head containing multiple magnetoresistive elements in one head.

Thin film magnetoresistive head for magnetic recording and reproducing

A thin film magnetic head device to be equipped on a magnetic recording and reproducing system can meet a plurality of recording formats and carry out stabilized recording/reproducing without depending on the running direction of the magnetic tape. There are combined either of at least two thin film magnetic heads for recording each having on a substrate a recording transducer for recording information on a magnetic tape or two thin film magnetic heads for reproducing each having a reproducing transducer for reading out information recorded on a magnetic tape or two thin magnetic heads for recording and reproducing .in which the recording transducer and the reproducing transducer exist together. According to the running direction of the magnetic tape, only the thin film magnetic head Which is situated at the downstream side in the running direction of the magnetic tape is activated to be always in an operating condition.

Thin film magnetic head device

Magneto-resistive head

A lamination type magneto-resistive head used for a magnetic reproducing apparatus is formed by laminating two magneto-resistive heads, at least with the position of two magneto-resistive elements substantially shifted from each other for lamination and also enabling a plurality of track formats to be conformed, thus making it possible to assure stable outputs at a low frequency range.

Lamination type magneto-resistive head

A thin film magnetic head includes an upper magnetic layer comprising a first yoke, a portion of which is divided into front and rear sections and which is provided near the divided sections with a magneto-resistive element, a second yoke provided adjacent to the opposite ends of the first yoke in a widthwise direction of a recording track and a third yoke provided between the first yoke and the second yoke and having a larger magnetic reluctance than those of the first and second yokes. In the above constitution, the first, second and third yokes can be mainly used in recording to record in an area of a large width on the recording medium, and only the first yoke can be used in reproducing to reproduce in an area of a small width on the recording medium, so that the reproducing output is not reduced when the recording medium experiences a running deviation.

Thin film magnetic head with wide recording area and narrow reproducing

There is disclosed a thin film magnetic head which requires less recording current, and is capable of recording and reproducing with a high sensitivity. To achieve this magnetic head, a third yoke of a high permeability is bridged across a notched portion of a second yoke between front and back portions of the second yoke constituting part of a magnetic circuit. With this construction, the third yoke serves to extremely reduce a magnetic resistance between the front and back portions of the second yoke, so that the recording current can be smaller, thereby enhancing the recording efficiency.

Thin film magnetic head of embodied recording and reproducing transducer

A magnetic head for multi-track data recording on magnetic tape is formed of a combination of two head modules, each having a linear array of thin-film transducer elements formed on a substrate, each of these arrays consisting of a mixture of write elements and read elements. These are positioned on the respective head modules such that when the head modules are combined with the substrates mutually opposing, pairs of transducer elements are formed for respective tape tracks, each pair consisting of a read and a write element. 'Read-after-write' recording confirmation can thereby be implemented together with bidirectional recording operation, by using only a combination of two head modules.

Magnetic head for multi-track recording having read and write

A magnetic head device of thin-film type having superior recording and reproducing characterisics. The magnetic head device has a non-magnetic substrate and lower and upper magnetic layers formed on the substrate. At least one of the magnetic layers has a double-layered structure composed of two soft magnetic layers. One of these soft magnetic layers, which is disposed at the inner side of the magnetic circuit, has a coercive force smaller than that of the other soft magnetic layer. The soft magnetic layer having the greater coercive force, at least at a portion thereof contactable with the recording medium, has a greater width than the soft magnetic layer of the smaller coercive force as viewed in the direction of the track.

Thin-film magnetic head device for recording and reproducing

A method of manufacturing a multiturn coil and a thin film magnetic head including a multiturn coil. This multiturn coil manufacturing method includes the following steps. First a laminate made up of conducting layers and insulating layers for coil is formed on a base member on a substrate and having a given inclination. Then this laminate is formed into a loop shape with a space or discontinuity thereon. In the next step, the upper part of the laminate on opposite sides of the space is removed to form a flat surface parallel to the substrate in which the ends of all the conducting layers are exposed. Finally, film conductive strips are connected between these exposed portions across the discontinuity to complete a multiturn coil.

Method for manufacturing multiturn thin film coil

A magnetic head having a high wear resistance and high workability such as by grinding, and a method for manufacturing the same. According to this method, at least a portion of that surface of the core forming the magnetic head or shielding case, which is to be brought into contact with a magnetic recording medium, is subjected to a boronizing treatment to form a boronized layer.

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Yao, Japan

Yuji Nagata