Sony Corporation

Takuji Shibata

Akio Takada

Tadayuki Honda

Norio Saito

Hideo Suyama

Moriaki Abe

Mamoru Sasaki

Yutaka Soda

Hiroaki Narisawa

Kenichiro Tsunewaki

Tadao Suzuki

Takashi Watanabe

Jin Sato

Tetsuo Sekiya

Munekatsu Fukuyama

Shuichi Haga

Koji Fukumoto

Kenji Yazawa

Yoshihiro Kanno

Yukio Kondo

A magnetic reluctance effect magnetic head in which a forward side electrode is stacked on at least the surface of a magnetic reluctance effect element facing a magnetic recording medium, and in which an upper magnetic pole is stacked on the forward side electrode for facing the magnetic reluctance effect element. A connecting length L1 between the magnetic reluctance effect element and the forward side electrode is shorter than a facing length L2 over which the upper magnetic pole and the magnetic reluctance effect element face each other via a magnetic gap G. The upper magnetic pole and the magnetic reluctance effect element have an area in which the upper magnetic pole and the magnetic reluctance effect element face each other over a distance g2 larger than a magnetic gap length g1 of the magnetic gap G. The upper magnetic pole may be formed to be progressively spaced apart from the magnetic reluctance effect element by being angled 30.degree. relative to the magnetic reluctance effect element, and the distance g2 may be progressively increased. With the magnetic reluctance effect magnetic head, the playback output may be improved and the magnetic head may be reduced in size and in the power consumption.

Magnetic reluctance effect magnetic head with the connection length of

A magneto-resistive effect type magnetic head employing a spin valve film in which the direction of magnetization of a free layer is constant even in the absence of an external magnetic field to assure magnetic stability. The magneto-resistive effect type magnetic head includes a magneto-resistive effect film of a planar substantially rectangular configuration, having its longitudinal direction substantially perpendicular to a magnetic recording medium sliding surface, a first electrode connected to a longitudinal end of the magneto-resistive effect film, a second electrode connected to the other longitudinal end of the magneto-resistive effect film and hard magnetic films arranged on both ends along the width of the magneto-resistive effect film. The magneto-resistive effect film is made up of at least a first ferromagnetic layer, a non-magnetic layer, a second ferromagnetic layer and an anti-ferromagnetic layer, layered together. The hard magnetic films has an electrical resistance larger than that of the magneto-resistive effect film.

Magneto-resistive effect magnetic head

The present invention provides a high quality magnetoresistance effect type magnetic head having an increased reproduction output and capable of applying a uniform bias magnetic field to a magnetoresistance effect layer without increasing an impedance. The magnetoresistance effect type magnetic head according to the present invention includes: a magnetic layer 11 magnetized approximately in a vertical direction to a plane 14 opposing to a magnetic recording medium; a non-magnetic insulation layer 12 formed on the magnetic layer 11; and a magnetoresistance effect layer 13 formed on the non-magnetic insulation layer 12 and exhibiting the magnetoresistance effect. In the longitudinal type magnetoresistance effect type magnetic head according to the present, the detection current supplied to a magnetoresistance element is prevented from flowing into a hard magnetic film to lower the head reproduction output.

Magnetoresistance effect type magnetic head

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 thin-film magnetic head in which magnetic stability of a magnetoresistance effect film is improved for further stabilizing the playback output. The thin-film magnetic head includes a magnetoresistance effect stabilizing layer 11 having a hard magnetic member 11d and a soft magnetic member 11e, a non-magnetic insulating layer 12 layered on the magnetoresistance effect stabilizing layer 11, a magnetoresistance effect layer 13 layered on the non-magnetic insulating layer 12 and a pair of electrodes connected on both ends of the magnetoresistance effect layer 13. Under the effect of the hard magnetic member 11d, the magnetoresistance effect layer 13 is reduced in coercivity and, under the effect of the soft magnetic member 11e, the magnetic filed which proves to be the saturation flex density is increased.

Thin-film magnetic head with MR element hard and soft magnetic films

A thin-film magnetic head improves magnetic stability of a magnetoresistance effect film 13 for further stabilizing the playback output. The thin-film magnetic head has a magnetoresistance effect stabilizing layer 11, a non-magnetic layer 12 and a magnetoresistance effect layer 13 exhibiting the magnetoresistance effect. The magnetoresistance effect stabilizing layer 11 has a hard magnetic film and a soft magnetic film. The magnetoresistance effect stabilizing layer 11 has a non-magnetic film 11c of a non-magnetic material in at least a partial area between a hard magnetic film 11b and a soft magnetic film 11d. In the thin-film magnetic head, there is produced a stable magnetostatic coupling action between the magnetoresistance effect stabilizing layer 11 and the magnetoresistance effect layer 13 for increasing the magnetic stability of the magnetoresistance effect layer 13 operating as a magnetically sensitive portion.

Thin-film magnetic head having magnetic resistance effect stabilizing

A magneto-resistance effect-type magnetic head according to the present invention can generate a high reproduction output by increasing a quantity of magnetic flux passing across an effective magneto-sensitive zone of a magneto-resistance effect element, while maintaining its inherent functions as a means for preventing unnecessary magnetic flux from entering the MR element or as a recording pole. The magneto-resistance effect-type magnetic head for reproducing signals from a magnetic recording medium, includes a magneto-resistance effect element, upper and lower magnetic layers between which the magneto-resistance effect element is interposed, and a low-permeability magnetic layer provided on at least one of surfaces of the upper and lower magnetic layers which surfaces are opposed to the magneto-resistance effect element, the low-permeability magnetic layer having a magnetic permeability not more than half of a magnetic permeability of the upper or lower magnetic layer.

Magneto-resistance effect-type magnetic head

A depth sensor for detecting a depth, when grinding the magnetic head in order to set the depth of the magnetic head to a predetermined length including an analog sensor having a resistor whose resistance changed continuously by being ground together with the magnetic head when grinding the magnetic head in a depth direction and for detecting the depth from said continuously changed resistance, and a digital sensor having a resistor whose resistance is changed non-continuously by being ground together with the magnetic head when grinding the magnetic head in the depth direction and for detecting the depth from the non-continuously changed resistance.

Depth sensor which detects grinding depth by means of change and

A magnetoresistance effect thin-film magnetic head superior in magnetic stability and capable of developing a high playback power. The thin-film magnetic head has a magnetoresistance effect stabilizing layer 11 inclusive a diamagnetic film or a hard magnetic film, a non-magnetic insulating layer 12 and a magnetoresistance effect layer 13 inclusive of a magnetoresistance effect film, layered together to form a magnetoresistance effect element 3. The thin-film magnetic head also has a non-magnetic insulating layer 4 arranged on a lateral surface of the magnetoresistance effect element 3 and a pair of electrodes connected to the magnetoresistance effect layer 13 on both ends of the upper surface of the magneto-resistance effect element 3. The playback signals are detected by the magnetoresistance effect of the magnetoresistance effect layer 13.

Thin-film magnetic head

A magneto-resistance effect type thin-film magnetic head for detecting reproduced signals by the magneto-resistance effect, which is suitable for detecting reproduced signals by magneto-resistance effects, is disclosed. The thin-film magnetic head includes a two-layered magneto-resistance effect element made up of a first magneto-resistance effect film and a second magneto-resistance effect film of substantially the same width as the first magneto-resistance effect film, layered with a non-magnetic insulating film in-between. Since the magneto-static coupling is produced between the first and second MR films, the magnetic state between the first and second MR films is stabilized. The film thickness contributing to the playback output can be reduced as in the case of a single-layer magnetic head constituted by a single-layer MR film for realizing a high playback output.

Thin film magnetic head and method for producing same

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 magnetoresistance-effect thin film head including a substrate, a magnetic field sensing element provided on the substrate, an electrode layer having portions respectively extending from the opposite ends of the magnetic field sensing element to apply a sense current to the magnetic field sensing element so that the sense current will flow in the direction of a signal magnetic field, an insulating layer formed over the magnetic field sensing element, a bias magnetic field creating conductor formed on the insulating layer so as to extend across the magnetic field sensing element, and a magnetic shielding layer shielding the magnetic field sensing element. At least a portion of the electrode layer and a portion of the bias magnetic field creating conductor are included in a conductive pattern.

Magnetoresistance effect thin film head with interconnected electrode

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.

Growing community of inventors

Miyagi, Japan

Takuji Shibata