Abstract: A magnetic head including a shielded MR element which incorporates a low reluctance path between the shields to reduce interference picked up by inductive reading of the shields. The low reluctance path is provided outside a conductive loop of material which includes the MR element and its associated leads. The low reluctance path may include a magnetic short between the two shields.

Abstract: A spin valve device containing a chromium or chromium and aluminum antiferromagnetic layer, which acts as a pinning layer for a magnetoresistive ferromagnetic layer, by exchange coupling. The antiferromagnetic layer has a tunable Neel temperature and anisotropy constant, and is corrosion resistant.

Abstract: A silicon dioxide passivation film highly resistant to humidity is formed to prevent the deterioration of the magnetic effects, to increase the resistance variation rate and to reduce the internal stresses of the ferromagnetic metal film of the MR element. After forming the ferromagnetic metal film, the silicon dioxide film is formed by a TEOS-O.sub.3 -based atmospheric pressure CVD method in a state where the substrate temperature is kept at or below 350.degree. C. The silicon dioxide film is not doped with phosphorus and sits thickness is kept within 1 .mu.m. On the other hand, apart from the above-described structure, the silicon dioxide film may as well consist of two layers, one doped with and the other not doped with phosphorus. Another method used to form the silicon dioxide film is an HMDS-O.sub.3 -based atmospheric pressure CVD method. As film formation is thereby possible at a substrate temperature of not more than 300.degree. C.

Abstract: The invention provides a magnetoresistance effects film including (a) at least two thin magnetic films deposited on a substrate, (b) at least one thin nonmagnetic film interposed between the thin magnetic films, and (c) a thin antiferromagnetic film disposed adjacent to one of the thin magnetic films between which the thin nonmagnetic film is interposed. A bias magnetic field of one of the thin magnetic films induced by the thin antiferromagnetic film has an intensity Hr greater than a coercivity H.sub.C2 of the other of the thin magnetic films which is remote from the thin antiferromagnetic film (Hr>H.sub.C2). The thin antiferromagnetic film has a superlattice structure composed of at least two of NiO, Ni.sub.x Co.sub.1-x O (x=0.1-0.9) and CoO. A ratio of Ni relative to Co in the number of atoms in the superlattice structure is set equal to or greater than 1.0.

Abstract: A method of manufacturing a magnetic field sensor having a stacked structure of:an exchange-biasing layer (2) comprising nickel oxide on a substrate (1) anda magnetic layer (3) which is exchange-biased with the exchange-biasing layer (2),whereby at least the exchange-biasing layer (2) is provided by sputter deposition using a sputter gas which comprises Ne and/or He. The magnetic layer (3) preferably comprises permalloy. In a particular embodiment, the magnetic layer (3) is separated from a second magnetic layer (5) by an interposed non-magnetic layer (4), so as to form a spin-valve trilayer.

Abstract: A position sensor comprising a scale structure 7 having magnetic poles positioned with a predetermined distance alternatively magnetized poles one to another, at least two magnetic sensing elements M11 and M12 having a resistance variable in response to the magnetic field of the scale structure, and external connecting terminals 14, 15, and 16 are connected for applying a voltage and for producing an output signal from the intermediate terminal. The terminals each is formed to have a width in the direction in parallel to the magnetic field being 2m times the pole width (m=1, 2, 3, . . . ) of the scale structure, thereby the terminals being prevented from the effect of resistance variation by the magnetic field to provide a position information with an increased accuracy.

Abstract: A magnetic field sensor is described that has a 0.25-0.6 micrometer thick magnetically active layer of very high electron mobility that consists essentially of epitaxial indium antimonide. The indium antimonide layer is disposed on a 0.03-1.0 micrometer thick buffer layer of In.sub.1-x Al.sub.x Sb, where "x" is about 0.01-0.2, that is substantially lattice-matched to the indium antimonide active layer.

Abstract: The magnetoresistive effect element in accordance with the invention has several aspects. For instance, the magnetoresistive effect element includes an artificial lattice multilayered structure composed of a thin magnetic layer and a non-magnetic layer at least once successively deposited, and a bias field applying device for applying a bias magnetic field to the artificial lattice multilayered structure so that an orientation of residual magnetization of one of the thin magnetic layers having a greater coercive force than that of an adjacent thin magnetic layer, is the same as an orientation of a bias magnetic field to be applied to the artificial lattice multilayered structure. The magnetoresistive effect element provides enhanced regenerated outputs and also improves the symmetry of regenerated waveforms.

Abstract: A magnetoresistance effect element according to the present invention comprises magnetic multilayer film having a non-magnetic metal layer, a ferromagnetic layer formed on one surface of the non-magnetic metal layer, a soft magnetic layer formed on the other surface of the non-magnetic metal layer, and a pinning layer which is formed on the ferromagnetic layer to pin a direction of magnetization of the ferromagnetic layer, wherein the ferromagnetic layer and the pinning layer are coupled to each other with epitaxial growth.

Abstract: A magnetoresistance effect film is disclosed. This magnetoresistance effect film comprises a substrate, at least two ferromagnetic thin films stacked one over the other on the substrate with a non-magnetic thin film interposed therebetween, and an antiferromagnetic thin film arranged adjacent to one of the ferromagnetic thin films. The antiferromagnetic thin film is a superlattice formed of at least two oxide antiferromagnetic materials selected from NiO, Ni.sub.x Co.sub.1-x O (0.1.ltoreq.x.ltoreq.0.9) and C.sub.o O. A biasing magnetic field Hr applied to the one ferromagnetic thin film located adjacent the antiferromagnetic thin film is greater than coercive magnetic force Hc2 of the other ferromagnetic thin film.

Abstract: A magnetoresistive spin valve sensor is described. Such a sensor is also known as a GMR sensor or giant magnetoresistive sensor. The layers (24, 26, 28) of the sensor are mounted on a substrate (20) having steps or terraces on one of its face. The steps or terraces on the substrate's surface cooperate with one or more of the ferromagnetic layers (24, 28) of the sensor to determine the layers' magnetic properties. Specifically, the thickness of one or more of the sensor's layers can be set above or below a critical thickness which determines whether the easy direction of uniaxial magnetization of a layer of that particular material is fixed or "pinned". If pinned, the layer has a high coercive field. Thus, the new device avoids a biasing layer to pin any of the magnetic layers. Preferably the easy axes of the first two ferromagnetic layers (24, 28) are set at 90.degree. to one another in the zero applied field condition by appropriate choice of layer thickness.

Abstract: The measurement of rotary position angle is done using magnetoresistive elements having a combined output which is a linear output that is not affected by a wide range of operating conditions. The magnetoresistive elements are placed on the surface of a cylindrical rod whose axis is perpendicular to the flux lines of a uniform magnetic field.

Abstract: An article that uses a magnetoresistive material comprising one or more CrO.sub.2 grains having an insulating material, advantageously Cr.sub.2 O.sub.3, along at least a portion of the grain boundary or boundaries, the magnetoresistive article advantageously exhibiting a magnetoresistance ratio greater than 12% at 5K and 20 kOe.

Abstract: Information is recorded by applying weak and strong magnetic fields to a giant magnetoresistive medium having a pair of ferromagnetic layers, a nonmagnetic interlayer, and an antiferromagnetic layer. The medium preferably has a magnesium-oxide base layer, and may also have an electrode layer. The weak magnetic field magnetizes the ferromagnetic layers in the antiparallel state. The strong magnetic field magnetizes the ferromagnetic layers in the parallel state, which has lower electrical resistance than the antiparallel state. The recorded information is reproduced by detecting the electrical resistance of the medium, either between two electrodes contacting the surface of the medium, or between the electrode layer in the medium and an electrode contacting the surface of the medium.

Abstract: A magnetoresistance effect device of the invention includes: a substrate; and a multilayer structure formed on the substrate. The multilayer structure includes a hard magnetic film, a soft magnetic film, and a non-magnetic metal film for separating the hard magnetic film from the soft magnetic film. The magnetization curve of the hard magnetic film has a good square feature, and the direction of a magnetization easy axis of the hard magnetic film substantially agrees to the direction of a magnetic field to be detected.

Abstract: The present invention provides a colossal magnetoresistant sensor, and in particular a colossal magnetoresistant sensor capable of responding to the low fields emanating from the recording media. The recording media typically emanates a low field on the order of 20 Oe which is insufficient to result in a significant change in resistance in a CMR layer of material. The colossal magnetoresistant sensor is comprised of a first magnetic layer; a colossal magnetoresistant layer and a second magnetic layer, where the colossal magnetoresistant layer is positioned between the first magnetic layer and a second magnetic layer. The first and second magnetic layers surrounding the colossal magnetoresistant layer control the field through and therefore the resistance of the CMR layer.

Abstract: A magnetoresistance effect element is provided with a magnetoresistance effect film (MR film) formed of alternative laminations of magnetic layers (for example, soft magnetic layers such as Fe--Ni--Co alloy layers) which are coupled anti-ferromagnetically with each other between adjacent magnetic layers and non-magnetic layers (for example, non-magnetic layers such as Cu layers) and provided with a bias soft magnetic layer (for example, SAL layer) for application of a bias magnetic filed to the magnetoresistance effect film, where the anisotropic magnetic field (Hk) in the plane of the bias medium layer is 5 Oe.ltoreq.Hk.ltoreq.15 Oe.

Abstract: A magnetoresistive device has an alloy film, including a ferromagnetic substance and a non-magnetic substance which is not soluble in solid phase in the ferromagnetic substance or is in a eutectic relation with the ferromagentic substance. The ferromagnetic substance forms grains in the non-magnetic substance, and the grains preferably have anisotropic shapes. The non-magnetic substance is conducting. The alloy film is composed of a plurality of alloy film stripes. Alternatively the magneto-resistive device includes a non-magnetic layer arranged between first and second magnetic layers, wherein the non-magnetic layer has 10 to 50 weight percent of grains of a magnetic substance dispersed therein.

Abstract: The invention provides a sensing device capable of outputting a correct signal precisely corresponding to a particular position (angle) of, for example a protruding or recessed portion of a rotating member made of a magnetic material.

Abstract: A tri-layer thin film magnetoresistive device using doped perovskite manganate thin films as ferromagnetic elements, wherein a current is transported through the tri-layer structure, is disclosed. A large magnetoresistance change of about a factor of two is obtained in a low magnetic field, less than 150 Oe, which is close to the coercivity of the material of the elements. This device demonstrates that low-field spin-dependent transport in the manganates can be accomplished and that the magnitude of the resulting magnetoresistance is suitable for magnetoresistive field sensor applications.

Abstract: A current limiter with a controllable resistance which assumes a low value during rated service and a high value during a short-circuit disconnect. The current limiter includes a thermoplastic resistive member between two flat, metallic electrodes. Each of the flat metallic electrodes has a surface profile on the side facing the thermoplastic resistive member. The resistive member has a surface profile complementary to the surface profile on the adjacent surfaces of the flat electrodes. The flat electrodes and the resistive member are thereby inseparably connected, with the flat electrodes and the resistive member being pressed together by a pressure force. The interlocking of the surfaces results in an especially rapid readjustment of the limiter resistance from its high-resistance state during a short-circuit disconnect back to the low-resistance state during rated service.

Abstract: A disk drive system having a spin valve (SV) magnetoresistive (MR) sensor having four leads, two leads for providing sense current to an SV element and two leads for providing current to an asperity compensation layer (ACL). The SV element as well as the hard bias layers are electrically insulated from the ACL by an antiferromagnetic layer made of an insulating material. The voltages developed across the SV element (voltages due to the presence of thermal asperities and voltages due to the presence of data fields) and the ACL (voltages due to the presence of thermal asperities) are applied to the inputs of a differential amplifier for substantial elimination of the thermal asperity signal.

Abstract: A method for maximizing the interfacial properties of magnetoresistive sensors, such as spin valve and GMR sensors used in storage devices, comprises selecting the materials for ferromagnetic layers and for electrically conductive spacers that are interposed between the ferromagnetic layers. The electronegativities of the selected materials are substantially matched so that an absolute value of the differences in electronegativities is minimized. The conductive spacer material provides a relatively low resistivity and a large mean free path. The sensors experience greater chemical and thermal stability, are corrosion resistant, and realize an increased signal output.

Abstract: The invention provides a sensing device capable of outputting a high-accuracy signal precisely corresponding to a particular position (angle) of a rotating member made of a magnetic material without being disturbed by external noise. The sensing device includes: a magnet for generating a magnetic field; a rotating member made of a magnetic material, for changing the magnetic field generated by the magnet, the rotating member being disposed a predetermined distance apart from the magnet; and a giant magnetoresistance device whose resistance changes in response to the change in the magnetic field caused by the rotating member of magnetic material, wherein the size L.sub.3 of the magnetic field sensing plane of the giant magnetoresistance device is set to a value less than the smallest value of the dimensions L.sub.1 and L.sub.2 of the protruding and recessed portions of the rotating member of magnetic material, that is, the size L.sub.

Abstract: In a magnetoresistance multilayer film comprising at least two magnetic layers on a substrate, with a nonmagnetic layer intervening between the magnetic layers, each interface between the magnetic layer and the nonmagnetic layer is corrugated in both X and Y directions of a substrate major surface. The corrugations of the interface are formed by providing the substrate surface with a multiplicity of asperities distributed in both X and Y directions and depositing magnetic layers and nonmagnetic layers thereon. The film shows a linear rise of MR change in an applied magnetic field within a very low range of 0 to about 40 Oe.

Abstract: In a magnetoresistance effect device that has leads, a magnetic gap layer, and a magnetic shield layer that are laminated on a magnetoresistance effect film, an insulation film is formed on a main surface at the edge portions of the leads (namely, on a non-tapered surface). Thus, a film quality deteriorated region of the magnetic gap layer is spaced apart from an electric field concentrated portion. In addition, the insulation film has a mask layer on a conductor layer formed on the magnetoresistance effect film. When a pair of leads are formed by the ion-milling process, a magnetic gap layer is formed with the mask layer on the non-tapered surface of the leads. Thus, since an insulation film is formed at the edge portions of the leads, the lower corner portion of the magnetic gap layer becomes an edge portion of the insulation film. In this portion, the deterioration of the film quality is inevitable. However, the electric field concentrated portion is still the edge portions of the leads.

Abstract: A magnetoresistance effect element comprises a magnetic body obtained by dispersing magnetic metal particles containing at least one magnetic element selected from the group consisting of Fe, Co, and Ni in a semiconductor matrix.

Abstract: Magnetic thin films 2 and 3 are stacked on a substrate 4 with a nonmagnetic thin film 1 interposed therebetween. An antiferromagnetic thin film 5 is arranged adjacent to one magnetic thin film 3. The inequality Hc.sub.2 <Hr is satisfied between a bias magnetic field Hr of the antiferromagnetic thin film 5 and coercive force Hc.sub.2 of the other magnetic thin film 2. At least a part of the antiferromagnetic thin film 5 comprises NiMn of an fct structure. Alternatively, the antiferromagnetic thin film 5 comprises a two-layer structure composed of a CoO layer deposited on a NiO layer to a thickness between 10 and 40 angstroms.

Abstract: Magnetoresistive elements according to this invention comprise magnetically soft material in close proximity to the magnetoresistive material, exemplarily a perovskite manganite. The combination results in magnetic field "amplification", with large resistance changes attainable at relatively low applied fields. The invention exemplarily is embodied in magnetic sensors, e.g., magnetoresistive read/write heads.

Abstract: A spin valve sensor and a method of fabricating the same are disclosed. The spin valve sensor includes a first layer of ferromagnetic material and a second layer of ferromagnetic material, with the second layer of ferromagnetic material having a thickness of less than about 100 .ANG.. A first layer of non-ferromagnetic conducting material is positioned between the first and second layers of ferromagnetic material. A NiMn pinning layer is positioned adjacent to the second layer of ferromagnetic material such that the pinning layer is in contact with the second layer of ferromagnetic material, wherein the NiMn pinning layer has a thickness of less than about 200 .ANG. and provides a pinning field for pinning a magnetization of the second layer of ferromagnetic material in a first direction.

Abstract: An apparatus for detecting precise angular positions of a rotating object. Two magnetoresistors (MRs) are positioned adjacent a target wheel attached to the rotating object, the target wheel having at least one element of finite length. Each MR is responsive to the passage of at least one of the elements as the target wheel is rotated, generating an analog signal with signal transitions between two voltage levels at the passage of the element's leading and trailing edges. The MRs are positioned relative to the elements such that their signals are phase shifted with respect to one another, resulting in time overlapping signals which intersect at a precise angular positions of the target wheel.

Abstract: An apparatus and method for reading an information signal from a magnetic storage medium using a magnetoresistive (MR) element, modifying the signal such that a thermal component of the signal representing a thermal response of the MR element is degraded, and altering the modified signal to produce a restored thermal signal substantially representative of the thermal component of the signal read from the storage medium. The information signal induced in the MR element is communicated from the MR element to an arm electronics (AE) module having a highpass filtering behavior. The AE module passes content of the information signal other than the thermal component content, thereby degrading the thermal component of the information signal. An inverse filter, implemented using an infinite impulse response (IIR) filter, receives the highpass filtered signal from the AE module and produces a restored thermal signal substantially representative of the thermal component of the information signal.

Abstract: A magnetic sensing structure includes a spin valve sensor having a pinned magnetic layer and a free magnetic layer, the direction of magnetization of the free layer varying as a function of the magnetic field applied to the structure. A multilayered magnetic keeper structure is provided to cancel the magnetostatic field from the pinned layer to provide an ideal bias profile for the structure in the absence of an applied magnetic field. Longitudinal magnetic bias may be applied to the spin valve sensor through a contiguous junction magnetic structure adjacent to the keeper structure and spin valve sensor.

Abstract: A giant magnetoresistive material film includes at least two ferromagnetic layers of a NiFe alloy or NiFeCo alloy, which are formed on a substrate through a nonmagnetic layer of Au, Ag, Cu or Cr, wherein magnetization of at lest one of the ferromagnetic layers is pinned by a coercive force increasing layer of .alpha.-Fe.sub.2 O.sub.3 provided adjacent thereto and having a thickness of 200 to 1000 .ANG. so as to increase coercive force of the ferromagnetic layer, and the other ferromagnetic layer has free magnetization so as to produce a change in resistance at a low magnetic field. The present invention also provides a method of producing the giant magnetoresistive material film and a magnetic head provided with the giant magnetoresistive material film.

Abstract: A magnetoelectric transducer is proposed using the GMR effect which operates stably even in a wider range of magnetic field, and over a wider temperature range, than currently available. Upon a substrate 5 there are formed a first magnetic layer 1, a non magnetic layer 3, a second magnetic layer 2, and a rare earth--transition metal alloy layer 4. The second magnetic layer 2 and the rare earth--transition metal alloy layer undergo exchange coupling. The axes of easy magnetization of the second magnetic layer 2 and the rare earth--transition metal alloy layer 4 lie along the surfaces of these layers. The composition of the rare earth--transition metal alloy layer 4 exhibits rare earth dominance at room temperature. The main component of the non magnetic layer 3 is Cu, and the thickness of this layer 3 is at least 1.5 nm.

Abstract: A magnetoresistive element includes a substrate, a magnetoresistive film arranged on the substrate and prepared from a non-magnetic conductive metal film containing grains consisting of a ferromagnetic metal atom or a ferromagnetic metal alloy dispersed therein so that the grain concentration is varied along the film thickness direction, a pair of current feeding electrodes arranged on the magnetoresistive film, and a pair of voltage reading electrodes arranged on the magnetoresistive film.

Abstract: A magnetic multilayer film having magnetoresistance (MR) is prepared by depositing at least two magnetic thin films having different coercive forces while interposing a non-magnetic thin film therebetween. A first magnetic thin film having a lower coercive force has a squareness ratio SQ.sub.1 and a thickness t.sub.1, a second magnetic thin film having a higher coercive force has a squareness ratio SQ.sub.2 and a thickness t.sub.2, and the non-magnetic thin film has a thickness t.sub.3. A first form of the invention requires 4 .ANG..ltoreq.t.sub.2 <30 .ANG., 20 .ANG.<t.sub.1 .ltoreq.200 .ANG., t.sub.1 >t.sub.2, t.sub.3 .ltoreq.200 .ANG., 0.7.ltoreq.SQ.sub.1 .ltoreq.1.0, and 0.1.ltoreq.SQ.sub.2 .ltoreq.0.8, thereby achieving a magnetic multilayer film which shows a great MR ratio of several percents under an external magnetic field of several Oe, an excellent rise across zero magnetic field and heat resistance. A second form of the invention requires 4 .ANG.<t.sub.2 <20 .ANG., 5 .ANG.<t.sub.

Abstract: An MR sensor having a nearly symmetric read sensitivity across the sensor by using permanent magnet boundary control. The sensor's MR element is patterned to eliminate portions of the MR element between the electrical contacts which contribute to undesired read sensitivity. The MR element is maintained in a single domain state using abutting permanent magnets electrically isolated from the MR element.

Abstract: A method of making an MR sensor having a nearly symmetric read sensitivity across the sensor by using permanent magnet boundary control. The sensor's MR element is patterned to eliminate portions of the MR element between the electrical contacts which contribute to undesired read sensitivity. The MR element is maintained in a single domain state using abutting permanent magnets electrically isolated from the MR element.

Abstract: A magnetoelectric conversion device comprises a magnetic recording medium magnetized with a repetitive signal in N and S poles that occur alternately at certain intervals and wherein said repetitive signal has a predetermined wavelength .lambda.. A magnetic sensor, facing said magnetic recording medium. The magnetic sensor changes its resistivity according to the magnetic flux of said magnetic signals. The magnetic sensor has a first current path and a second current path connected in series and forming at least one interconnect. An output terminal is connected to each interconnect. A terminal of a power source is connected to both ends of each current path. Each of the current paths comprises two unitary segments and a plurality of magnetic resistor elements formed by turning a magnetic resistance strip n times (where n is an integer of 0 and greater). The first current path comprises a third unitary segment and a fourth unitary segment. The third unitary segment comprises a magnetic resistance element.

Abstract: A magnetic field sensor having a plurality of interconnected magnetoresistive magnetic field sensing structures with at least one thereof having a permeable material mass adjacent thereto to shield it from externally applied magnetic fields. Another has a shunting structure adjacent a side thereof to remove a fraction of externally applied magnetic fields from affecting same.

Abstract: A tunneling ferrimagnetic magnetoresistive sensor that has a .DELTA.R/R greater than that of known magnetoresistive sensors, and that, with appropriate electrode materials, can undergo a substantial change in resistance in response to a magnetic field in the intensity range of 10s of Oe, which is typical of the intensity of the magnetic fields encountered in magnetic recording media such as discs and tapes. The tunneling ferrimagnetic magnetoresistive sensor is composed of a stack of thin-film layers that include a layer of a ferrimagnetic material, a layer of a magnetic material, and a layer of an insulator interposed between the layer of the ferrimagnetic material and the layer of the magnetic material. The ferrimagnetic material is conductive. The magnetic material is also conductive and has a coercivity substantially different from that of the ferrimagnetic material.

Abstract: The invention relates to a current sensor or transducer (10) for measuring the current flowing through an electric conductor (11), comprising a magnetoresistive tape (12) surrounding the conductor and whose ends (13, 14) are to be connected to a device for measuring said current, characterized in that the tape (12) is shaped like a tube with an axis centred on the conductor and in that it is formed with a multilayer, metallic, magnetic structure, whose layers constitute the same number of stacked elementary tubes concentric to said axis.

Abstract: A spin valve magnetoresistive sensor includes a substrate and a layered structure formed on the substrate. The layered structure includes a pair of thin film layers of ferromagnetic material separated from each other by a nonmagnetic spacer. The direction of magnetization of one of the thin film layers is pinned by a first permanent magnet layer. A second permanent magnet layer is located adjacent to the other of the thin film layers for longitudinal biasing purposes. The first permanent magnet layer has significantly higher coercivity than the second permanent magnet layer.

Abstract: A giant magnetoresistive dual spin valve sensor employs at least one magnetic biasing layer located adjacent to an antiferromagnetic layer in the spin valve structure which includes two pinned ferromagnetic layers. The antiferromagnetic layer simultaneously pins the biasing layer and the ferromagnetic layer nearest the antiferromagnetic layer. This structure eliminates the bias point offset present in prior dual spin valve sensors.

Abstract: A method for determining through a test structure a longitudinal magnetic exchange field within a patterned exchange biased magnetoresistive (MR) sensor element. To practice the method, there is first provided a substrate. Formed upon the substrate is a patterned magnetoresistive (MR) layer which has a projected length upon the substrate and a projected width upon the substrate. There is formed at a pair of separated locations over the patterned magnetoresistive (MR) layer a pair of patterned conductor lead layers. The pair of patterned conductor lead layers is separated by a track width of the patterned magnetoresistive (MR) layer, where the track width is smaller than the projected width.

Abstract: A magnetic information detecting apparatus is disclosed including a recording medium in which magnetic information is recorded and a magnetic field detection unit for detecting the magnetic information, the magnetic field detection unit having its magnetic field detecting section formed of a magnetoresistive element or a Hall element, the magnetic field detecting section surrounding peripheries of the recording medium. The recording medium has a substantially circular cross section. The magnetoresistive element has a structure of an artificial multilayer film formed by alternately stacking a conductor layer and a magnetic layer. The magnetic field detection unit has a soft magnetic body for conducting a magnetic field to the magnetic field detecting section.

Abstract: A multi-function switch includes a casing, a key top member, two magnets, two magnetic detectors and a micro-computer. The key top member is mounted on the casing to permit both liner movement and rotational movement in a plane parallel with a bottom face of the casing. The two magnets are arranged on the key top member to be apart from each other at a predetermined distance. The two magnetic detectors are arranged on the casing to face the magnets' respectively, at respective neutral positions in the liner movement and rotational movement. The micro-computer detects a ratio of respective voltages generated from the magnetic detectors and further processes the obtained ratio as a desired operational signal.

Abstract: The invention concerns a magneto-resistive magnetic sensor comprising a magneto-resistive element, the resistance of which varies as a function of the applied magnetic field and two pole pieces that collect the magnetic field to be detected so as to concentrate it in the magneto-resistive element, each pole piece being positioned to partially overlap the magneto-resistive element, a current I passing through this magneto-resistive element, wherein the zones of the magneto-resistive element that are overlapped by pole pieces are cut out such that the current that passes through the magneto-resistive element is located in a zone in the air gap between the two pole pieces.

Abstract: In the present invention, electrons flow through a free or excitable magnet, or reflect from it, to make its magnetization respond. To accomplish this, the spin vectors of the flowing electrons are preferentially polarized by an auxiliary ferromagnet, whose moment orientation is fixed. The electrons flow between the fixed and free ferromagnets through a non-magnetic metallic spacer which is thick enough to make the static inter-magnetic exchange coupling negligible. While transmitting thru or reflecting from the free ferromagnet, the spins of the moving electrons interact by quantum-mechanical exchange with the local, permanently present, spontaneously-polarized electron spins of the free magnet. This interaction causes a transfer of vectorial angular momentum between the several metallic layers in the device which causes the magnetization vector of the free magnet to change its direction continually with time. Thus excited, the magnetization vector will precess about its original axis.