Matsushita Electric Industrial Co., Ltd.

Other

Toshio Fukazawa

Yuji Nagata

Kumiko Wada

Satoru Mitani

Yoshihiro Tosaki

Masaya Sakaguci

Tsuguhiro Korenaga

Shinji Uchida

Masaya Sakaguchi

Hiroyasu Tsuji

Terumi Yanagi

Norimoto Nouchi

Toshihiro Kuriyama

Yuji Matsuda

Shogo Nasu

Akira Ahagon

Shougo Nasu

Yoshihiro Tozaki

Norimoto Nochi

A thin film head comprising a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer; and a pair of the right and the left laminated longitudinal biasing layers, each of the layers containing a hard magnetic layer, a nonmagnetic layer and a soft magnetic layer provided on said free magnetic layer of GMR element. Said hard magnetic layer and said soft magnetic layer are antiferromagnetically exchange-coupled via said nonmagnetic layer, and said hard magnetic layer and said free magnetic layer locating next to said hard magnetic layer are ferromagnetically coupled. The present invention contains also a method for manufacturing the thin film head.

Method for manufacturing thin film head

A magnetoresistive thin film head comprises a magnetoresistive element including an antiferromagnetic layer, a pinned layer, a nonmagnetic conductive layer and a free magnetic layer, and a pair of the right and the left laminated transverse biasing layers, each including a nonmagnetic layer, a ferromagnetic layer and an antiferromagnetic layer, provided on the free magnetic layer constituting said magnetoresistive element. The layer thickness of said nonmagnetic layer has been established to a certain specific value so that magnetizing direction in said free magnetic layer opposing to the ferromagnetic layer via said nonmagnetic layer assumes a direction that is opposite to that of said ferromagnetic layer.

Method for manufacturing a thin film head

In accordance with the present invention, in a magnetic recording medium for perpendicular magnetic recording, a recording characteristic which is not inferior to that of double-layer medium and a resolution of reproduction which is not inferior to that of single layer medium are provided. On a non-magnetic substrate, a soft magnetic layer for increasing a perpendicular component of recording magnetic field in a perpendicular magnetic recording layer is formed. A non-magnetic layer for suppressing extension of signal magnetic field loop from recording magnetization in the perpendicular magnetic recording layer is formed on the soft magnetic layer. The perpendicular magnetic recording layer is formed on the non-magnetic layer. The non-magnetic layer has a thickness required to effectively reduce the signal magnetic field loop. The required thickness exceeds 20 nm.

Perpendicular magnetic recording medium and apparatus including a soft magnetic layer, an at least 20 nm thick non-magnetic layer, and a 50-90 nm gap length

A thin film head includes a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer, a free magnetic layer, and a pair of the right and the left laminated longitudinal biasing layers. Each of the biasing layers contains a high coercivity ferromagnetic layer, a nonmagnetic layer and a low coercivity ferromagnetic layer provided on the free magnetic layer of the GMR element. The high coercivity ferromagnetic layer and low coercivity ferromagnetic layer are antiferromagnetically exchange-coupled via the nonmagnetic layer, and the high coercivity ferromagnetic layer and free magnetic layer located next to the high coercivity ferromagnetic layer are ferromagnetically coupled.

MR thin film head with longitudinal-biasing multi-layers of antiferromagnetically-coupled high and low coercivity layers

A magnetoresistive thin film head comprises a magnetoresistive element including an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer, and a pair of the right and the left laminated transverse biasing layers, each including a nonmagnetic layer, a ferromagnetic layer and an antiferromagnetic layer, provided on the free magnetic layer constituting said magnetoresistive element. The layer thickness of said nonmagnetic layer has been established to a certain specific value so that magnetizing direction in said free magnetic layer opposing to the ferromagnetic layer via said nonmagnetic layer assumes a direction that is opposite to that of said ferromagnetic layer.

Thin film head with transverse biasing layers

This invention provides a light absorber which can be used for optical equipment like optical-disk equipment and a liquid crystal display. The light absorber has a layered structure including a light absorbing layer and a transparent layer. The light absorbing layer absorbs a reflected light from the inside of the absorber as well as incident light into the absorber while the transparent layer helps attenuate the reflected light by interference of light. One of the light absorbing layers which is thicker than others may work as a shading layer for the incident light.

Light absorber and optical equipment

A prism and an optical pickup employing such prism includes a parallel prism having a polarization beam splitter film and a reflection film. The polarization beam splitter film is formed on an angled plane of a glass material having an approximate parallelogram cross-section, and consists of a multi-layer film of a composite film made of Si and SiO.sub.2-x (x&lt;0.5) and multiple layers of multiple dielectric films. The reflection film is formed on an angled plane of the same glass material approximately parallel to the angled plane on which the polarization beam splitter film is formed, and consists of a multi-layer film of a composite film made of metal Si and oxide SiO.sub.2-x (x&lt;0.5) as a high refractive film and multiple layers of multiple dielectric films as a relatively low refractive film.

Composite prism and optical pickup using the same

In an integrated thin film magnetic head, a write pole or inductive head I.sub.h includes first and second magnetic cores magnetically coupled to form a magnetic circuit and a coil formed between the first and second magnetic cores. An MR element read pole or MR head MR.sub.h includes first and second yokes, an MR element and a bias conductor for applying a biasing magnetic field on the MR device, and the first magnetic core or the second magnetic core constitutes the second yoke.

Integrated thin film magnetic head

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

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.

Growing community of inventors

Kyoto, Japan

Toshio Fukazawa