Abstract: A printed circuit fluxgate sensor for use in magnetic gradient detection devices and the like includes a highly magnetically saturable core formed as a flat, closed loop that is bonded between two planar substrate members. An excitation coil is formed on the outer surfaces of the substrate members by masking and etching a layer of a conductive metal in a pattern of tracks that extend across the core. Each track end is connected through a metal plated bore hole through the substrates from one track end to the next adjacent track end on the opposite substrate to form a current path circling the core in a toroidal fashion. Indicia are provided on the sensor that define the mechanical axis and the magnetic axis of the sensor.

Abstract: A magnetic field detection circuit comprises a magnetic impedance device, a detection coil wound around or arranged close to the impedance device, an electric current application circuit for applying a pulse-shaped high frequency electric current substantially equally swinging to the positive side and the negative side to the magnetic impedance device, and a detection circuit for detecting a voltage generated in the detection coil in response to rises and falls of the applied pulse-shaped electric current and outputting a signal corresponding to the intensity of the external magnetic field on the basis of the outcome of the detection. The magnetic field detection circuit can provide nil-point setting on a stable basis by means of a simple circuit arrangement at low cost.

Abstract: A gradiometer integrating pickup coils comprises pickup coils 11Xp, 11Xn magnetically connected to a SQUID through associated input coils 2, and pickup coils 11Yp, 11Yn magnetically connected to a SQUID through associated input coils 2, respectively. Two superconducting loops are connected in series to each of the SQUIDs, when viewed from Josephson junctions 5. The input coils 2 form superconducting closed loops together with the pickup coils 11Xp, 11Xn, 11Yp, 11Yn associated therewith. The SQUIDs are respectively connected to form an 8-figured shape as a whole such that currents flow in two superconducting loops of each SQUID in opposite directions to each other, with respect to the application of a uniform field, in order to reduce environmental magnetic field noise.

Abstract: A magnetic impedance element including a substrate made of a non-magnetic material, a thin-film magnetic core formed on said substrate, and first and second electrodes disposed on both ends of said thin-film magnetic core in a longitudinal direction thereof, characterized in that said thin-film magnetic core is formed by laminating a plurality of magnetic films through non-magnetic thin-films.

Abstract: An electric current sensor which includes a pair of magnetic detectors arranged near a signal line, flowing through which is an electric current to be detected. Additionally, a differential amplifier is included for differentially amplifying two signals obtained by the paired magnetic detectors, detecting a magnetic field from the electric current flowing through the signal line, and outputting a detection signal for the detected electric current. The paired magnetic detectors are arranged adjacent to each other along a first straight line and sandwiching between them a second straight line. The first straight line is perpendicular to but spaced from the signal line, and the second straight line crosses perpendicularly to both the first straight line and the signal line. The paired magnetic detectors have the same magnetic field detecting direction, which may be parallel or inclined relative to the second straight line.

Abstract: A fluxgate sensor is integrated in a printed circuit board. The fluxgate sensor has two bar-type(or rectangular-ring shaped) soft magnetic cores to form a closed magnetic path on a printed circuit board and an excitation coil in the form of a metal film is wound around the two bar-type soft magnetic cores either in a united structure that winds the two bar-type soft magnetic cores altogether, or in a separated structure that winds the two bar-type soft magnetic cores respectively, both in a pattern of number ‘8’. A pick-up coil is mounted on the excitation coil, either winding the two bars altogether, or respectively, in a solenoid pattern. The fluxgate sensor integrated in the printed circuit board can be mass-produced at a cheap manufacturing cost. The fluxgate sensor also can be made compact-sized, and at the same time, is capable of forming a closed-magnetic path.

Abstract: A fluxgate sensor is integrated in a semiconductor substrate. The fluxgate sensor has two bar type soft magnetic cores, or a rectangular-ring type soft magnetic core to form a closed magnetic path on the semiconductor substrate, with an excitation coil formed of a metal layer either of the united structure winding the two bar-type cores or two longer sides of the rectangular-ring type core altogether and substantially in a number ‘8’ pattern, or of a separated structure winding the two bar type cores or two longer sides of the rectangular-ring type core, respectively, in a number ‘8’ pattern.

Abstract: A weak-magnetic field sensor using printed circuit board manufacturing technique and a method of manufacturing the same which detects earth magnetism to obtain positional information is disclosed. The sensor comprises a magnetic layer patterned in a certain shape; a first stacked board stacked on a lower surface of the magnetic layer and formed with a first driving pattern; a second stacked board stacked on an upper surface of the magnetic layer and formed with a second driving pattern, the first and second driving patterns being electrically connected to each other; a third lower stacked board stacked on a lower surface of the first stacked board and formed with a first pickup pattern; and a third upper stacked board stacked on an upper surface of the second stacked board and formed with a second pickup pattern, the third lower and upper stacked boards being electrically connected to each other.

Abstract: The present invention is a two-dimensional magnetic sensor, comprising two miniaturized MI elements and an integrated circuit, which boasts a wide magnetic field measurability range, low power consumption, and an extremely small size, which is suitable for use as an electronic compass in, for instance, mobile devices like mobile phones.

Abstract: A magnetic force microscopy (MFM) probe has an elongated probe tip with a planar surface onto which a uniformly thick magnetic film is formed. The magnetic film may comprise either a seed layer, an exchanged coupled ferromagnetic/anti-ferromagnetic double layer, and a capping layer, or a seed layer, an antiferromagnetic layer, a synthetic triple layer consisting of a thin non-magnetic layer sandwiched by two ferromagnets, and a capping layer. The multiple layers are annealed below the Neel temperature of the anti-ferromagnetic layer and field cooled to establish an unidirectional exchange bias along the tip surface. The coated portion of the tip is made sufficiently long so that the interaction between the tip and sample mainly happens at the bottom end of the tip.

Abstract: A magnetic sensor comprises a thin-film-like magnetic tunnel effect element (magnetoresistive effect element) 11. A coil 21 is disposed in a plane under the magnetic tunnel effect element 11 and parallel to a thin-planar film surface of the element. The coil 21 is a double spiral type coil which includes a first spiral conductor portion 21-1 and a second spiral conductor portion 21-2. The magnetic tunnel effect element 11 is disposed between a spiral center P1 of the first conductor portion 21-1 and a spiral center P2 of the second conductor portion 21-2 in a plan view. The first and second conductor portions 21-1 and 21-2 are connected such that electric currents in the same direction pass through a part of the first conductor portion 21-1 that overlaps the magnetic tunnel effect element 11 in a plan view and through a part of the second conductor portion 21-2 that overlaps the magnetic tunnel effect element 11 in a plan view.

Abstract: A magnetic sensor device has a magnetic sensor having a magnetic material whose threshold frequency is changed by a magnetic field to be detected, and the device has the so-called electromagnetically-coupled current path which is affected by the magnetic material in order to electrically detect the threshold frequency of the magnetic material. The current path is connected to an oscillator circuit, which is set so that its oscillation frequency is changed by a change in the threshold frequency of the magnetic sensor. In the magnetic sensor device, the magnetic field to be detected causes a change in the oscillation frequency of the oscillator circuit, and the change in the frequency is extracted as a magnetic field detection signal.

Abstract: In a high-frequency impedance type magnetic head having high impedance and capable of efficiently detecting a change in impedance, an electrically conductive metal film is sandwiched between two soft magnetic films, and the two soft magnetic films form a portion of a magnetic path. The thickness of one soft magnetic film is smaller than the thickness of the other soft magnetic film. The electrically conductive metal thin film has a pair of electrodes at respective ends thereof, to which are connected an oscillator for applying a high frequency carrier signal to the electrodes and a high frequency amplifier having a demodulator circuit. Further, an electrically conductive metal film winding is provided, and a DC current is applied to the electrically conductive metal film winding at the time of reproduction, while on the other hand, a signal current is applied to the electrically conductive metal film winding at the time of recording.

Abstract: A transpinnor-based magnetometer is provided having four resistive elements exhibiting GMR in a bridge configuration. A bias current is applied to the bridge, yielding an output if the bridge is unbalanced due to changes in the GMR resistors. An oscillating magnetic field is applied inductively to the GMR resistors alternately driving them between saturated magnetic states. The drive conductors are physically arranged so that an external magnetic field will oppose the applied field in two resistors and aid the applied field in the other two. The output is nonzero only when the sum of the applied field and external field exceeds the GMR coercivity in one pair of GMR films and not the other. The frequency of the output signal can be varied by switching the polarity of the bias current and controlling the phase with respect to the drive current.

Abstract: A magnetic detection element of the present invention for detecting a strength of an external magnetic field, comprises a magnetic thin film formed on a single non-magnetic substrate, a circuit that applies a high-frequency current to the magnetic thin film, and a spiral type planar coil that is stacked on the magnetic thin film through an insulating layer, wherein the magnetic thin film is formed in a longitudinal shape and magnetic anisotropy is given so that direction of easy magnetization axis is orthogonal to a longitudinal direction of the longitudinal shape.

Abstract: There is provided a thin-film magnetic field sensor, which has a simple structure and a high detecting sensitivity, and reduces measurement errors due to temperature variation or the like. In the thin-film magnetic field sensor according to the present invention, two arms of a bridge circuit are formed of an element 5 having a giant-magneto-resistant thin-film, and soft magnetic thin-films disposed one on either side thereof, with electrical terminals, and an element 10 having a giant-magneto-resistant thin-film, and conductive films disposed one on either side thereof, with electrical terminals. The electrical resistance value of the element 10 has sensitivity relative to the magnetic field, such that it is substantially zero when the magnetic field is small, but it changes equally to the element 5 due to causes other than the magnetic field.

Abstract: A seed layer is formed with a Cr layer in which the direction of a crystal face in at least one crystal grain is oriented in a different direction from the direction of an equivalent crystal face in another crystal grain. Consequently, wettability of the seed layer can be markedly improved and the unidirectional exchange bias magnetic field in a pinned magnetic layer can be increased while permitting the surface of each layer on the seed layer to have good lubricity.

Abstract: The invention relates to an assembly for measuring a magnetic field, comprising at least a first layer assembly (8) and at least a second layer assembly (10), whereby the first layer assembly (8) and the second layer assembly (10) have a hard magnetic layer (16), a layer (18) which acts as a tunnel barrier and lies adjacent to the hard magnetic layer and a soft magnetic layer (20) which lies adjacent to the layer (18) which acts as a tunnel barrier. The layer assemblies (8, 10) are located in a bridge circuit for determining the electric resistance. The invention is characterized in that the second layer assembly (10) also has an electrically conductive anti-ferromagnetic layer (22) lying adjacent to the soft magnetic layer (20), or an electrically conductive artificial anti-ferromagnet lying adjacent to said soft magnetic layer (20). The invention also relates to a method for producing the inventive assembly.

Abstract: A magnetic impedance element including a substrate made of a non-magnetic material, a thin-film magnetic core formed on said substrate, and first and second electrodes disposed on both ends of said thin-film magnetic core in a longitudinal direction thereof, characterized in that said thin-film magnetic core is formed by laminating a plurality of magnetic films through non-magnetic thin-films.

Abstract: A magnetic field probe includes a substrate and a conductive layer provided on the substrate. The conductive layer has a coil, lead wires, and pads. The coil has at least one turn and outputs a signal indicative of a magnetic field from a device under test in a vicinity of the magnetic field probe. The lead wires extend from the coil to the pads, the signal from the coil being transmitted to the pads through the lead wires. An isolating layer of a dielectric material is provided on the lead wires to protect the lead wires between the coil and the pads in the conductive layer. A shielding layer of a conductive material is provided on the isolating layer to protect the isolating layer. The shielding layer prevents distortion of the magnetic field at the lead wires in conjunction with the isolating layer.

Abstract: A method and apparatus for sensing a presence of a magnetic field and/or a magnitude of a magnetic flux density of the magnetic field. A direct-current voltage is applied across a first layer of a conductive material, so that a direct current flows in a first direction through the first layer. A second layer of a piezoelectric material is integrated with or positioned adjacent or abutting the first layer. The first layer and the second layer are exposed to or positioned within a magnetic field. A Lorentz force is thus caused, preferably in a direction which is generally perpendicular to the first direction of the direct current and a second direction of the magnetic field to deflect the piezoelectric material thereby causing an output voltage in response to the Lorentz force. A magnetic flux density can be calculated as a function of the piezoelectric output.

Abstract: A magnetic sensor is constructed to be capable of detecting the change of tunnel current due to co-tunneling effect at a high S/N ratio by using a tunneling magneto-resistive element having a first magnetic layer of a soft magnetic material formed on a flat substrate, first and second tunnel barrier layers formed on the first magnetic layer, magnetic particles of a ferromagnetic material provided between the first and second tunnel barrier layers, and a second magnetic layer of a soft magnetic material formed on the second tunnel barrier layer so as to create tunneling junctions.

Abstract: A magnetic detector which includes a first thin-layer element and a second thin-layer element made of magnetic material with magnetic anisotropy in the plane possessing, in this plane, two easy axes of magnetization. A coercive field of one of the first and second thin-layer elements has a value different from that of the other thin-layer element. The two thin-layer elements have elongated and mutually parallel shapes perpendicular to their direction of easy magnetization in the absence of a magnetic field. The width of these thin-layer elements is such that it obliges at least one of the thin-layer elements to have its magnetization oriented along the length of the thin-layer element when there is no external magnetic field. Such a magnetic field sensor may find particular application to the measurement of magnetic fields.

Abstract: A magnetic impedance element including a substrate made of a non-magnetic material, a thin-film magnetic core formed on said substrate, and first and second electrodes disposed on both ends of said thin-film magnetic core in a longitudinal direction thereof, characterized in that said thin-film magnetic core is formed by laminating a plurality of magnetic films through non-magnetic thin-films.

Abstract: Here is disclosed a MI element made of thin film magnetic material utilizing a magnetic impedance effect comprising a substrate, first and second magnetic materials successively laminated on a surface of the substrate each in the form of thin film wherein the first magnetic material has its axis of easy magnetization Jm1 declined at an angle of &agr;° and the second magnetic material has its axis of easy magnetization Jm2 declined at an angle of −&agr;° with respect to a reference line Oo which is a direction corresponding to a path of high frequency current Iac so that the axes of easy magnetization of the first and second magnetic materials may intersect each other. Such MI element made of thin film magnetic material obtains linear magnetic field sensor characteristics exhibiting a remarkably large variation of impedance in response to a relatively low external magnetic field without any demand for bias magnetic field.

Abstract: A high sensitivity magnetic field sensor is described. The sensing element is a stress-sensitive, negative-magnetostriction, melt-extracted amorphous wire, in which a strong magneto-impendance effect develops when the wire is connected to conventional electronic circuitry, which can be an impedance-meter. An a.c. current is provided to the wire and its relative change in impedance is measured. Simultaneously, the wire is submitted to a longitudinal d.c. magnetic field, H. A saturating d.c. field pulse is also applied to this wire at the beginning of the operating cycle. Tensile stress is further generated in the wire by pulling one end of the wire with a given force. This stress can be fine-tuned for sensitivity and bias with the help of a suitable mechanism. All these elements are packaged in a rugged non-magnetic enclosure, which permits easy and reliable connection of the sensor to said conventional electronic circuitry.

Abstract: In a magnetic impedance element in which an element body is formed of a magnetic thin film formed on a non-magnetic substrate, and when a high-frequency current is supplied to the magnetic thin film, an impedance between both ends of the magnetic thin film changes in accordance with an external magnetic field, the magnetic thin film is formed in a slender zigzag pattern obtained by folding a straight line in parallel several times, and an easy axis of magnetization of the magnetic thin film is so set as to be directed along the longitudinal direction of the pattern. Also, assuming that a thickness of the magnetic thin film is T, a line width of the pattern is W, and a length of the pattern is L, T is in a range of 1 to 5 &mgr;m, and L/(W×T) is in a range of 10 to 400×106 m−1.

Abstract: A GMI sensor for determining spin rate of a rotating body within an external magnetic field is presented. The sensor comprises an oscillator generating an AC drive signal at an oscillator output terminal. A voltage divider circuit includes a first terminal AC coupled to the oscillator output terminal through a coupling capacitor, and a second terminal electrically connected to a reference ground. The voltage divider circuit further includes a GMI fiber having a GMI junction terminal. The fiber is disposed in fixed relation to the rotating body such that impedance of the fiber is modulated by the external magnetic field to provide a modulated drive signal at the GMI junction terminal. A signal processing circuit is electrically connected to the GMI junction terminal to processes the modulated drive signal and provide an output signal indicative of the spin rate of the rotating body.

Abstract: A differential spiral magnetic field sensing device is constructed such that two soft magnetic film cores are arranged parallel to each other, each soft magnetic film core is divided into several parts in a detection axial direction to reduce anti-magnetic field components, the differential excitation coil, the magnetic flux variation detecting coil and the zero magnetic field detecting coil are laminated and wound turn by turn around the soft magnetic film cores, and there is no induced voltage waveform to the magnetic flux variation detecting coil without external magnetic field. Also, in order to minimize the leaked magnetic field components of the soft magnetic film cores, the soft magnetic film cores are sandwiched to form closed magnetic paths, and the differential excitation coil, the magnetic flux variation detecting coil and the zero magnetic field detecting coil are spirally laminated around the sandwiched soft magnetic film cores.

Abstract: The present invention is directed to a magnetic thin-film device whose operating frequency band ranges from several millihertz (MHz) to several gigahertz (GHz) and which is used as an inductor for a switching power supply, a noise filter, a reception circuit for receiving a quasi-microwave and a magnetic sensor. In this device, uniaxial magnetic anisotropy is guided to a magnetic layer, and the magnetic layer is sandwiched between dielectric layers to form a propagation path of electromagnetic wave. A microstrip line is provided on the top surface of the propagation path, while an insulative underlying substrate is formed on the bottom surface thereof with a lower grounded conductor interposed therebetween. Thus, the wavelength of the propagation path can be shortened to miniaturize the device. The device is rapidly improved in characteristics and miniaturized further, resulting in reduction in manufacturing costs.

Abstract: A differential solenoidal magnetic field sensing device is a magnetic field sensor fabricated on a microscopic scale and is constructed by two soft magnetic film cores laminated on a semiconductor substrate, an excitation of the soft magnetic film cores, and a magnetic flux variation detecting coil formed of a spirally wound metal film pattern. Since two soft magnetic film cores constitutes closed magnetic paths, leakage of magnetic flux can be minimized. Also, the magnetic sensing device is a differential type sensor, the combination of driving signals can be offset.

Abstract: A biaxial flux gate type magnetic sensor has a core which is made of a magnetic thin film in the shape of a loop, patterned upper and lower electrically conductive thin-film layers respectively above and below this core each with an insulating layer in between, and electrically conductive connecting members each extending between and electrically connecting these upper and lower electrically conductive layers. These upper and lower electrically conductive layers are patterned and the contact portions connect them such that they together provide an excitation coil and four detection coils. These coils are each formed so as to be wound helically and uniformly around and along a circumferential direction of the loop-shaped core by passing both inside and outside the loop. The loop is of a shape which is symmetrical with respect to two mutually perpendicular directions and is divided into four mutually symmetric sections.

Abstract: A triplate stripline on a multilayer circuit board includes an inner conductor sandwiched between two ground patterns having a finite pattern width that is 10 times the pattern width of said inner conductor or less. The two ground patterns are short-circuited on opposite transverse ends thereof by a plurality of vias disposed in a longitudinal direction which is a signal transmitting direction of the stripline. An adjacent stripline is of the same structure as the triplate stripline. Each of the striplines has a cross-sectional shape in which one inner conductor is surrounded by the two ground patterns and the vias on the opposite sides. The inner conductor is thus prevented from suffering ambient electromagnetic noise and electromagnetic interference such as crosstalk or the like.

Abstract: A high-sensitivity magnetic sensor capable of detecting a nonequilibrium spin, uses an almost-spin-polarized ferromagnetic oxide in a high-quality trilayer arrangement including an intermediate layer made of a conductive nonmagnetic oxide not reacting with a ferromagnetic metallic oxide and having a lattice matching between a spin injection layer and a spin detection layer.

Abstract: In a magnetic sensor having soft magnetic metallic elements disposed in opposite sides of a bridge circuit for sensing an external magnetic field by using a phenomenon where a skin depth of the soft magnetic metallic elements changes in dependence on a strength of the external magnetic field, each of the soft magnetic metallic elements is formed in a zigzag shape having parallel sections extending in a direction of the external magnetic field. The soft magnetic metallic element may have a multi-layer structure where soft magnetic layers are laminated with a non-magnetic insulator layer interposed therebetween.

Abstract: The present invention provides a magnetic-field sensor using a magnetic substance. In the magnetic-field sensor, a transmission-line element constituted of a conductor layer, dielectric layer and a magnetic layer is inserted in a feedback circuit of a phase-shift type oscillation circuit using an open-loop operational amplifier as an amplifier. An output of the operational amplifier is fed back to an input thereof through the transmission-line element. Thus, a variation in oscillation frequency depending upon the intensity of an external magnetic field is detected as an output of the sensor.

Abstract: In a magnetic detecting element utilizing a magnetic impedance effect, a high-permeability magnetic film is formed on a non-magnetic substrate and has magnetic anisotropy in a predetermined direction in the plane of the magnetic film. A high-frequency current is applied across two point in a direction perpendicular to the direction of the magnetic anisotropy, and a change in impedance generated between the two points is converted into an electric signal to obtain an output.

Abstract: A shielded magnetic head includes a magnetically shielded gap and first to fourth conductive magnetic films disposed in the gap. The first to fourth conductive magnetic films, each extending parallel to a tip face of a magnetic head to be opposed to a magnetic recording medium, are aligned at a distance from one another in a direction perpendicular to the tip face so as to be away from the tip face in ascending order and connected to one another so as to form a bridge circuit. The distance between the first conductive magnetic film and the tip face is set so that a signal magnetic field from the magnetic recording medium is applied to the first conductive magnetic film. By canceling impedance components that do not vary depending on a magnetic field, the shielded magnetic head detects only impedance components that vary depending on a signal magnetic field.

Abstract: A magnetic field sensor has a first conductor, a first insulating film, a second conductor, a second insulating film and a third conductor. The first conductor is composed of a “C-shaped” portion, which is formed in a C-like shape, and a linear portion, which is connected to one side of the “C-shaped” portion which is opposite to a gap of the “C-shaped” portion. The first insulating film is formed on the first conductor and has a hole in a predetermined position. The second conductor is formed in a ladle-like shape, and is formed on the first insulating film such that its one side corresponding to the front end of the ladle overlaps with a straight line, through which an outer edge of one end and an outer edge of the other end of the “C-shaped” portion.

Abstract: A magnetic sensor for detecting magnetic fields deriving from a magnetic body to detect any magnetic body on a non-magnetic body by moving relative to the non-magnetic body in prescribed relative moving directions along the surface of the non-magnetic body includes a magnetizing magnet in which a line connecting the N and S poles thereof is a direction substantially orthogonal to, and of which one pole is arranged either in contact with or in proximity to, the surface of the non-magnetic body; and a magnetism detecting element having two magnetic detectors arranged along a magnetic field detecting direction, the magnetic field detecting direction being orthogonal to the relative moving directions in a surface parallel to the surface of the non-magnetic body, wherein the magnetic body is magnetized by the magnetizing magnet along with the movement relative to the non-magnetic body, and magnetic fields according to the quantity of the magnetized part of the magnetic body are differentially detected by the two m

Abstract: A magnetic field detection device that detects two components of an external magnetic field. The device uses the magneto-impedance effect in ferromagnetic amorphous wire. A detection coil wrapped around the amorphous wire detects the magnetic flux change of the amorphous wire, which is proportional to the external magnetic field. The sensitivity of the device is increased due to circuitry that extracts the initial output pulse. It is also increased with the use of negative feedback and with the comparison of differential outputs. The two sets of detection elements are placed orthogonally for greatest sensitivity. Resin molding is employed for easy handling. This detection device can be used as part of a compass.

Abstract: Sensors, systems and methods for measuring magnetic field strengths in both AC and DC magnetic fields by using CMR material in tunable, radio-frequency LC oscillators are disclosed.

Abstract: A magnetic sensor (31) comprises an insulator substrate (37) having first and second surfaces opposite to each other, a soft magnetic element having first and second ends opposite to each other and mounted on the first surface of the insulator substrate, and a conductor mounted on the second surface of the insulator substrate, and an output port coupled to the first and the second ends of the soft magnetic element for deriving an impedance of the soft magnetic element between the first and the second ends. The impedance changes in dependence upon a magnetic field strength applied to the soft magnetic element. In the magnetic sensor (31), the soft magnetic element is a soft magnetic wire (33). The conductor is a ground conductor (35) to be grounded. The magnetic sensor may further comprise a short-circuiting conductor (39) connecting the first end of the soft magnetic wire with the ground conductor while the output port is coupled to the short-circuiting conductor and the second end of the soft magnetic wire.

Abstract: A tire (12) used includes a steel belt in its outer circumferential portion. A magnetic sensor (14) including a pair of magnetic detection elements (18A, 18B), which are arranged so that their magnetic detection directions become parallel to each other or series each other, is set in the vicinity of a rear tire (12) in a trunk room of a vehicle (10). Changes in magnetic field upon revolution of the tire (12) are differentially detected by the magnetic detection elements (18A, 18B), and the revolution of the tire (12) is detected on the basis of the differentially detected output waveform. Among a plurality of peaks present in the differentially detected output waveform, a peak, the potential difference from the immediately preceding peak of which is equal to or larger than a predetermined threshold value, is detected as an effective peak, which is effective for tire revolution detection, and the revolution speed of the tire is calculated by detecting the number of effective peaks.

Abstract: A magnet layer or antiferromagnetic thin film layer composed of a thin film serving as a bias magnetic field applying member is provided at both ends of a magnetic thin film having a magneto-impedance effect so that a bias magnetic field Hbi is applied to the magnetic thin film layer in parallel with the direction of application of an external magnetic field Hex to the magnetic thin film layer. As the magnetic thin film layer, a soft magnetic material having the composition ColTamHfn, FehRiOl, (Co1-vTv)xMyOzXw, T100-d-e-f-gXdMeZfQg or T100-p-q-f-gSipAlqMeZfQg is used.

Abstract: A magneto-impedance element comprises an alloy composed of at least one of Fe, Co and Ni. The alloy has a mixed texture of an amorphous phase and a fine crystalline phase having an average crystal grain size of 50 nm or less. The magneto-impedance element shows a change in impedance in response to an external magnetic field by applying an alternating current. The magneto-impedance element is applied to an azimuth sensor, an autocanceler, or a magnetic head.

Abstract: A tire (12) used includes a steel belt in its outer circumferential portion. A magnetic sensor (14) including a pair of magnetic detection elements (18A, 18B), which are arranged so that their magnetic detection directions become parallel to each other or series each other, is set in the vicinity of a rear tire (12) in a trunk room of a vehicle (10). Changes in magnetic field upon revolution of the tire (12) are differentially detected by the magnetic detection elements (18A, 18B), and the revolution of the tire (12) is detected on the basis of the differentially detected output waveform. Among a plurality of peaks present in the differentially detected output waveform, a peak, the potential difference from the immediately preceding peak of which is equal to or larger than a predetermined threshold value, is detected as an effective peak, which is effective for tire revolution detection, and the revolution speed of the tire is calculated by detecting the number of effective peaks.

Abstract: A magnetic sensor includes: an oscillating circuit for allowing an a.c. magnetic field into a magnetic impedance element made of a ferromagnetic substance, having first and second electrodes on both ends thereof in a longitudinal direction thereof and having a structure in which a bias coil and a negative feedback coil are wound around the ferromagnetic substance through an insulator; a detecting circuit for detecting an a.c. voltage of the magnetic impedance element due to a change in the impedance of the magnetic impedance element which is caused by an applied external magnetic field; a peak holding circuit for holding the peak value of the output voltage of the detecting circuit; and an amplifying circuit for differentially amplifying the output of the peak holding circuit.

Abstract: A magnetic field sensor which includes a planar thin-film element made of a crystalline magnetoresistive material exhibiting resistivity anisotropy in a plane, having a first and a second easy axis of magnetization. The planar thin-film element has electrical connections allowing a first electrical measurement current to flow through the planar thin-film element in a first direction, as well as two other electrical connections allowing a voltage to be measured in a second direction transverse to the first direction. The two easy axes of magnetization have comparable magnetization values.

Abstract: A magnetic sensor includes a bobbin having one surface provided with a toroidal groove, and a toroidal inductor accommodated in the groove. The toroidal inductor has a toroidal core and an excitation coil wound on the toroidal core. The excitation coil has a conductive pattern of a plurality of thin-film linear conductors individually extending in a radial direction on a surface of the bobbin and on inner side and bottom surfaces of the toroidal groove with a predetermined angular space, a toroidal core received in the groove, and a plurality of connecting wires each of which is bridged over the toroidal groove and toroidal core to interconnect an inner end of one of the thin-film linear conductors and an outer end of a next adjacent one of the thin-film linear conductors. The conductive pattern and the connecting wires form the excitation coil wound around the toroidal core. Thus, the toroidal inductor is formed in the toroidal groove.