Sony Corporation

Hideo Suyama

Shigeyoshi Imakoshi

Yutaka Soda

Tetsuo Sekiya

Takuji Shibata

Norio Saito

Munekatsu Fukuyama

Mamoru Sasaki

Akio Takada

Yasuhiro Iida

Kenichiro Tsunewaki

Hiroyuki Uchida

Hiroaki Yada

Shuichi Haga

Tomio Kobayashi

Hiroshi Takino

Masana Ugaji

Masayuki Nakayama

Yutaka Souda

Nobuhiro Sugawara

Jin Sato

Kazuo Kurihara

Junkichi Sugita

Toru Katakura

Shigenori Yamaoka

Iwao Abe

Sadaaki Sakurai

Yoshihisa Kawamura

Toshio Aizawa

Noboru Wakabayashi

Toshinaga Endo

Akinobu Kusuhara

Kietsu Iwabuchi

Chizuru Ohshima

Mikiya Kurosu

Shigeyoshi Imakoshi, Deceased

Nobuhiro Terada

Takeyuki Fuse

Fumi Sugawara

Zenkichi Nakamura

A geomagnetic direction sensor has a plurality of magnetic cores for converging terrestrial magnetism arranged circumferentially with pre-set gaps, and magneto-resistive effect devices in the gaps so as to lie substantially at right angles to the direction of the magnetic field in the gaps. The geomagnetic direction sensor has at least a pair of magneto-resistive effect devices lying substantially at right angles to each other. The magnetic core is formed of a magnetic material having soft magnetic properties. The current is supplied to the excitation coils placed around the magnetic core for applying a bias magnetic field to the magneto-resistive effect devices. Another set of magneto-resistive effect devices are connected in series with the magneto-resistive effect devices arranged within the gap so as to be substantially parallel to the direction of the magnetic field.

Geomagnetic direction sensor

In a magnetoresistance thin film magnetic head, a bias conductor and a magnetoresistive magnetic sensing section are electrically connected to each other in series. Further, the bias conductor (7) is formed in such a pattern as to have a width and distance from a magnetic recording medium facing surface which become larger as it is away from a portion transversing the magnetoresistive magnetic sensing section.

Magnetoresistance thin film magnetic head having reduced terminal count;

A magneto-resistance effect magnetic head having a uniform bias distribution and adapted for avoiding shorting between a magneto-resistance device and a bias conductor wherein a magneto-resistance device 5 and a bias conductor 6 for applying a bias magnetic field to the magneto-resistance device 5 are interposed between a lower shielding magnetic member 1 and an upper shielding magnetic member 2. The bias conductor is embedded in a groove formed in the shielding magnetic member provided on the opposite side of forward and rear electrodes with respect to the magneto-resistance effect device.

Magneto-resistance effect head with insulated bias conductor embedded in

A magneto-resistance effect type magnetic head having high output can be obtained as a reproduction head for a rotating drum type VTR by only providing a conventional rotary transformer with a rotor and a stator for supplying a bias current without a need for a special mechanism for transmitting a direct current. There is provided a magneto-resistance effect type magnetic head device to be mounted on a rotating drum having a bias conductor and a sense conductor, including a rotary transformer connected to the bias and sense conductors wherein an alternating current having a frequency lower than the frequency of a recording signal is applied to at least one of stator channels facing rotor channels of the rotary transformer. A current is applied to at least either the bias conductor or sense conductor at the stator side of the rotary transformer to produce a non-direct current at a terminal on the rotor side of the rotary transformer connected to the magneto-resistance effect type magnetic head only in a time zone when the magneto-resistance effect type magnetic head is not required to reproduce the recording signal and to produce a direct current at a terminal on the rotor side in a time zone when the recording signal must be reproduced.

Magneto-resistive effect type magnetic head device

A magneto-resistive effect thin-film magnetic head including a magnetic layer exhibiting a magneto-resistive effect, the magnetic layer having a longitudinal axis and two ends positioned at opposite ends of the longitudinal axis, and a flux guide layer of a high magnetic permeability soft magnetic material formed at an overlapping one end of the magnetic layer, the flux guide layer having two opposite ends longitudinally aligned with the longitudinal axis of the magnetic layer. On overlapping both ends of the flux guide layer, there are formed separate hard fills operating as permanent magnets.

Magneto-resistive effect thin-film magnetic head

Magneto-resistance effect type magnetic head device

A composite thin film recording/reproducing head comprises, in an integral laminate construction: a magneto-resistance effect thin film reproducing head having a magnetoresistance effect element; and an inductive thin film recording head. The track width of the magnetoresistance effect thin film reproducing head is greater than that of the inductive thin film recording head. The reproducing output of the composite thin film recording/reproducing head can be enhanced without entailing increase in reproducing output noise and the variation of the reproducing output can be suppressed, so that the composite thin film recording/reproducing head has improved reproducing output characteristics.

Composite thin film recording/reproducing head with MR reproducing head

A magneto-resistance/inductive integrated composite magnetic head which has a stabilized reproduction output and is high in reliability. The magnetic head comprises a composite magnetic head including a magneto-resistance effect type head and an inductive type head integrated with each other and a recording coil, and an electric circuit for supplying, after recording, the recording coil of the composite magnetic head with an electric current which attenuates in a fashion of an alternating current from a value of a recording current or a value around or higher than such value of a recording current to another value in the proximity of the zero level.

Magnetic recording and reproducing apparatus having magneto-resistance

A magnetoresistance effect type thin film head (A) constructed in a manner that a magnetoresistance effect element, that is, an MR element (1) is disposed perpendicularly to a head surface a, and among two electrodes (2a) and (2b) led out from both ends of the MR element (1), the one electrode (2a) is exposed to the head surface a but the other electrode (2b) is not exposed to the head surface a, wherein the one electrode (2a) exposed to the head surface a is connected to a ground voltage Vss, thereby decreasing the change in voltage difference between the electrode (2a) of the MR element (1) and a disc surface b to prevent the electrical breakdown of the thin film head (A).

Magnetoresistance effect type thin film head

A magneto-resistance effect type magnetic head incorporates a grounded conductive layer, a second thin film magnetic core and an MR sensing part, the conductive layer being located near the thin film magnetic core, the layer and the core being electrically connected. The conductive layer is further connected electrically to an electrode of the MR sensing part, the electrode facing an air bearing surface. This setup protects the MR sensing part from static electricity destruction, thus providing a magneto-resistance effect type magnetic head of high reliability.

Magneto-resistance effect magnetic head with static electricity

A magneto-resistance effect type thin film magnetic head which does not produce significant Barkhausen noises and has stabilized characteristics even where the track width is smaller than, for example, 10 .mu.m. The magnetic head comprises a base member, a lower layer thin film magnetic core and an upper layer thin film magnetic core layered on the base member in such a manner that a magnetic gap is formed between front ends thereof, the gap being open to an opposing face of the magnetic head which is in contact with or opposed to a magnetic record medium, and a magneto-resistance effect magnetic sensing section disposed in the magnetic gap between the lower and upper layer thin film magnetic cores. The front end of the lower layer thin film magnetic core which defines the magnetic gap has a width selected to be smaller than the width of the front end of the upper layer thin film magnetic core which defines the magnetic gap so as to define a track width of the magnetic gap.

Specific core structure in a magneto-resistance head

A magnetoresistance effect type thin film magnetic head comprising an MR element with electrodes provided at a fore end and a rear end thereof in the direction to confront a magnetic recording medium, wherein the electrode at the fore end of such MR element is electrically connected to a shielding magnetic layer to thereby eliminate any electrical instability at the fore end of the MR element, hence averting the characteristic instability in a playback mode while minimizing the unsteady generation of noise. The thin film magnetic head further comprises a first conductor having a great capacity and disposed in the proximity of the MR element, and a second conductor having a capacity smaller than that of the first conductor and connected to the fore-end electrode of the MR element. Such first and second conductors are connected to respective ground potentials independently of each other, thereby averting breakdown of the magnetic head that may otherwise be caused by the static charge generated due to the rotation of the magnetic recording medium during the operation.

Magnetoresistance effect type thin film magnetic head with noise

A MR magnetic head with a sensing element which comprises a plurality of superposed magnetic layers which have a magnetoresistance effect in at least one and a nonmagnetic intermediate layer sandwiched between the magnetic layers, and a sensing current is fed so as to flow in the sensing element in the same direction as a signal magnetic field which is applied to the element. Each of the magnetic layers is formed so as to have an easy axis of magnetization which is substantially perpendicular to the signal magnetic field or to have an isotropic magnetic characteristic in the magnetic film plane, which eliminates Barkhausen noise.

Magnetic transducer head utilizing magnetoresistance effect

A yoke type magnetic transducer head utilizing a magnetoresistance effect in which a magnetoresistance effect sensing portion is provided so as to magnetically couple a cut-away portion in a magnetic circuit including an operation gap and a magnetic yoke having in its one portion the cut-away portion and in which a first bias magnetic field is applied to the magnetoresistance effect sensing portion by a first magnetic flux that is generated when a current is flowed through the magnetoresistance effect sensing portion, or when a current is flowed through both the magnetoresistance effect sensing portion and a bias conductor, which includes a hard magnetic layer for generating a second magnetic flux by which a second bias magnetic field is applied to the magnetoresistance effect sensing portion and for passing through the magnetic yoke a magnetic flux which cancels at least a part of the first magnetic flux which passes through the magnetic yoke.

Flux cancelling yoke type magnetic transducer head

A combination magnetic transducer head apparatus which can easily achieve initial formatting of data tracks of a rotating magnetic recording medium such as a hard disk without using a specific separate initial formatting system. The apparatus comprises a magnetic head for initial formatting, another magnetic head for servo control and a magnetic recording and playback head all mounted on a head slider. In the apparatus, at least one track is first recorded on a magnetic disk by the magnetic head for initial formatting and then another track is recorded by the magnetic recording and playback head while the first track is scanned by the magnetic head for servo control whereafter such a series of operations are repeated until completion of recording of all tracks required.

Magnetic transducer combination with formatting, data, and servo heads

Growing community of inventors

Miyagi, Japan

Hideo Suyama