Hitachi, Ltd.

Hitachi Metals, Ltd.

Research Development Corporation of Japan

Hitachi Maxell, Limited

Hitachi Denshi Kabushiki Kaisha

Hitachi Research Dev. Corp.

Mitsuhiro Kudo

Noriyuki Kumasaka

Shigekazu Otomo

Hideo Fujiwara

Takeo Yamashita

Noritoshi Saito

Yoshihiro Shiroishi

Kazuo Shiiki

Shinji Takayama

Kiminari Shinagawa

Takeshi Kimura

Teizo Tamura

Yasunobu Ogata

Nobuyuki Sugishita

Yoshizo Sawada

Nobuo Kobayashi

Hiroshi Yamaguchi

Hitoshi Nakamura

Yoshio Homma

Masao Mitani

Ushio Kawabe

Isamu Yuito

Noboru Shimizu

Yoshinobu Tarutani

Juichi Morikawa

Yoshihiro Hamakawa

Tsutomu Iimura

Hideo Zama

Atsushi Saiki

Sadanori Taguchi

Takeshi Tottori

Osamu Inagoya

Masahide Suenaga

Mitsuo Abe

Takayuki Kobayashi

Yasuo Tsukuda

Minoru Yamano

Masashi Hayashi

Teizou Tamura

Hirotomo Ogihara

Yoshio Aoki

Akira Usui

Kiyoshi Ishihara

Juiti Morikawa

Shigeo Aoki

An amorphous magnetic alloy of Co-Nb-Zr system contains Co, Nb and Zr and has a composition which falls, in terms of atomic percent, within the region defined by straight lines connecting, in a ternary composition diagram assuming the total of contents of these three elements to be 100, a point (81% Co, 14% Nb, 5 Zr), a point (88% Co, 9% Nb, 3% Zr), a point (86.5% Co, 12.5% Nb, 1% Zr) and a point (81% Co, 18% Nb, 1% Zr). Disclosed also is a magnetic head having a core at least a part of which is constituted by this amorphous magnetic alloy. This magnetic head, when used in combination with a metal powder tape having a high coercive force, provides a remarkably increased recording-reproducing output.

Amorphous magnetic alloy of Co-Nb-Zr system and magnetic head made from

Magnetic head having an integrated recording and playback head and an

A ferromagnetic material is composed of an iron alloy which contains 2 to 12% by weight of silicon and 5 to 25% by weight of at least one element selected from the group consisting of ruthenium, rhodium, palladium, iridium, platinum, gold and silver. This ferromagnetic material exhibits a high saturation flux density and good corrosion resistance. Excellent magnetic characteristics are obtained by a multilayered film which is obtained by alternatingly laminating the above ferromagnetic material and a spacer layer composed of other material. Further, a markedly increased recording density is exhibited by a magnetic head for perpendicular magnetic recording, when the end of the main pole is composed of the ferromagnetic material.

Ferromagnetic material and a magnetic head using the same material

A multilayered ferromagnetic amorphous alloy film is constituted by a plurality of main ferromagnetic material alloy films of a ferromagnetic amorphous alloy laminated one upon another with a spacer ferromagnetic material layer interposed therebetween, the spacer ferromagnetic material layer being of a ferromagnetic material different from the ferromagnetic alloy. Also disclosed is a magnetic head employing the above-described multilayered film for, at least, a portion of a core thereof. The multilayered film has excellent magnetic characteristics and is easily patterned.

Multilayered ferromagnetic amorphous alloy film and magnetic head

The invention discloses a magnetic recording and reproducing system using a composite magnetic head whose surface facing a magnetic recording medium is composed primarily of a ferromagnetic metal and a high permeability ferrite single crystal, and which has a region close to a gap and composed of the ferromagnetic metal, wherein the composite magnetic head is arranged in such a fashion that the {110} plane of the high permeability ferrite single crystal is made to substantially coincide with a plane forming a principal magnetic circuit of the composite magnetic head, that the &lt;100&gt; direction lying inside the {110} plane is inclined at an angle of from 15.degree. to 75.degree. with respect to a direction perpendicular to the surface facing the magnetic recording medium, and that the magnetic recording medium travels in a direction which is relatively the same as, and parallel to, a vector formed by projecting a vector extending from the inside to the outside of the surface facing the magnetic recording medium in the &lt;100&gt; direction, on the surface facing the magnetic recording medium. This magnetic recording and reproducing system can remarkably reduce the step occurring on the surface facing the magnetic recording medium due to wear caused by the travel of the recording medium, and can reduce any output deterioration and fluctuation resulting from the step.

Magnetic recording and reproducing system with composite magnetic head

A magnetic head having a pair of core halves each combined through a magnetic gap, each of the core halves comprising a core base having slanted side surfaces on the side opposing to the magnetic gap and a magnetic thin layer formed on the surfaces of the core base on the side opposing the magnetic gap with magnetic material of high saturation magnetic flux density, the minimum value of the sum of products of vertical cross sectional areas of the respective magnetic paths of each of the core halves except for the path of the magnetic gap and the respective saturation magnetic flux densities of the respective parts is greater than the product of the area of the magnetic gap and the saturation magnetic flux density of the magnetic thin layer.

Magnetic head to effect high density magnetic recording

Amorphous alloys having high strength, high hardness, high crystallization temperature, high saturation magnetic induction, low coercive force, high magnetic permeability and particularly low deterioration of magnetic properties with lapse of time, have a composition formula of

Amorphous alloys

There is provided a structure of a composite type magnetic head and its manufacturing method. The composite type magnetic head comprises: two high permeability ferrite blocks with projections having nearly edged sections formed thereon; magnetic films having a high saturation flux density deposited on the side faces of the projections, the magnetic films confronting each other via a functional gap near front ends of said projections; guard films deposited over the magnetic films comprising a non-magnetic material; and non-magnetic materials filled on the guard films up to side face of the coil. This magnetic head exhibits excellent recording and reproducing characteristics. The contour effect is negligibly small. The reaction between the magnetic film and the non-magnetic material is prevented by the guard film.

Composite type magnetic head for recording and reproducing high

A magnetic film structure comprises at least one magnetic film unit wherein a plurality of main magnetic films of 0.05 to 0.5 .mu.m thickness made of a magnetic alloy containing iron or cobalt as principal constituent and having a high saturation magnetic induction of 10,000 gauss or more and a magnetostriction of 10.sup.-6 or less are laminated through intermediate magnetic films made of a magnetic material such as a nickel and iron alloy or amorphous magnetic alloy different from that of the main magnetic film and being so thin that the influence of coercive force of the intermediate magnetic film does not come out. A plurality of the magnetic film units are also laminated through non-magnetic insulating films. The magnetic film structure has high saturation magnetic induction and low coercive force.

Magnetic film structure

A magnetic recording and reproducing apparatus comprises a magnetic head having magnetic cores in which at least portions thereof in the vicinity of a gap are made of M.sub.n -Z.sub.n ferrite single crystal and planes of the magnetic cores forming a principal magnetic circuit are formed by {110} planes of the ferrite and &lt;100&gt; directions contained in the {110} planes are inclined to a surface facing a magnetic recording medium, and means for relatively moving the magnetic recording medium in an opposite and parallel direction to a projection vector on said surface facing said recording medium, of a vector directed from a site far from the surface facing the magnetic recording medium to a site near said surface in the &lt;100&gt; direction projected on the surface facing the magnetic recording medium. The present magnetic recording and reproducing apparatus exhibits both high wear resistance and excellent read/write characteristic.

Magnetic recording and reproducing apparatus

A magnetic head core and a method of fabricating same, wherein a magnetic circuit is constituted by a pair of magnetic films having a V-shaped cross section which face each other at each protrudent section through the gap material. The cross-sectional portion of the V-shaped film is exposed to the surface facing the magnetic recording medium. The protrusions of the magnetic film pair have tip planes parallel to each other and substantially perpendicular to the moving direction of the magnetic recording medium. The tip plane has a width defined by the line of intersection between the plane and the surface facing the magnetic recording medium in correspondence to the recording track width. At least one of the magnetic films has a window for winding an excitation coil. The magnetic film is formed on the non-magnetic protection member having a V-shaped protrusion. The magnetic head has superior recording and reproducing characteristics in a wide frequency band with less rubbing noise, high wear-resistivity and high productivity, and operates without the pseudo gap effect. The magnetic head core is fabricated through the steps of forming a coil winding groove in the gap forming plane of a non-magnetic core block, forming a number of parallel grooves perpendicularly to the winding groove so that a number of V-shaped protrusions are produced, forming a magnetic film on the surface of the protrusions, forming a gap plane after the magnetic film has been coated with non-magnetic material, and splitting the block and then combining the two core blocks to complete a magnetic head core.

Magnetic head and method of fabricating same

Herein disclosed is a thin film magnetic head which is so constructed that a conductor layer arranged in a non-magnetic insulating layer isolating two magnetic poles and adapted to form a coil of plural turns has a height made larger than the width and gap thereof. A method of fabricating that head includes the step of forming a non-magnetic insulating layer, the step of etching the insulating layer by using a mask layer formed thereover as a mask, the step of depositing a metal for providing a conductor layer, the step of removing the mask layer together with the metal thereover, and the step forming a coating of a non-magnetic insulating layer thereover, thereby to form the conductor layer. The head thus fabricated has its magnetic recording and reproducing characteristics improved.

Thin film magnetic head and fabricating method thereof

A magnetic head having a magnetic core formed by facing a pair of magnetic substances through a working gap at a head section confronting a magnetic recording medium is disclosed in which at least one of the magnetic substances has magnetic anisotropy, and an angle .alpha. (in a C-shaped core half) and/or an angle .alpha.' (in an I-shaped core half) between a core surface confronting the magnetic recording medium and a direction having a maximum magnetic permeability in a main magnetic circuit plane of the magnetic substance having magnetic anisotropy is made larger than an orientation angle of the above direction for making minimum the magnetic reluctance of the main magnetic circuit of the magnetic core by .beta. (for .alpha.) and/or .beta.' (for .alpha.') to improve the recording/reproducing characteristic of the magnetic head, where .beta. is given by a formula ##EQU1## is equal to or less than 25.degree., D indicates a depth of the working gap, L* indicates an effective length of an oblique part for forming the working gap, and min [a, b] indicates the smaller of a and b.

Magnetic head

A magnetic head which uses single crystal Mn-Zn ferrite containing up to 7% by weight of SnO.sub.2 occluded therein without being allowed to separate and which has such a construction that glass having a contraction rate lower than that of ferrite is filled in the narrowed portion near the gap, the plane forming the principal magnetic circuit of the core is allowed to coincide with the {110} plane of the ferrite and an angle .theta. between the &lt;100&gt; direction inside the {110} plane of the ferrite and the gap-forming plane is from 5.degree. to 40.degree. or 85.degree. to 120.degree.. The magnetic head having such a construction has a reduced modulation noise and extremely excellent write-and-read characteristics.

Amorphous alloy for magnetic head core represented by the general formula, (Fe.sub.x Co.sub.1-x).sub.a Cr.sub.b Si.sub.c -B.sub.1-a-b-c, where the value of x is 0.04-0.07, the value of a is 0.73-0.75, the value of b is 0.005-0.03, and the value of c is 0.02-0.06. The present amorphous alloy has high permeability, high saturation flux density, low magnetostriction, and low magnetic after-effect at the same time, and has distinguished characteristics for magnetic head core.

Amorphous alloy for magnetic head core

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Tokyo, Japan

Mitsuhiro Kudo