Abstract: This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formulaG.sub.d .ltoreq.0.13 P.sub.T B.sub.s (.lambda.+4.3)-2.1.The magnetic disk rotation means rotate the magnetic disk at a speed of 24 m per second or more.

Abstract: In a magneto-optical recording apparatus, a magnetic head is employed so as to perform vertical, or perpendicular magnetic recording. The magnetic head is constructed of a slider and a plurality of magnetic cores symmetrically positioned with respect to an axis of a magnetic recording medium. Each of the magnetic cores includes a main core, a return path core, and a gap.

Abstract: A thin film magnetic head includes an upper magnetic layer comprising a first yoke, a portion of which is divided into front and rear sections and which is provided near the divided sections with a magneto-resistive element, a second yoke provided adjacent to the opposite ends of the first yoke in a widthwise direction of a recording track and a third yoke provided between the first yoke and the second yoke and having a larger magnetic reluctance than those of the first and second yokes. In the above constitution, the first, second and third yokes can be mainly used in recording to record in an area of a large width on the recording medium, and only the first yoke can be used in reproducing to reproduce in an area of a small width on the recording medium, so that the reproducing output is not reduced when the recording medium experiences a running deviation.

Abstract: A method of flux conduction comprising providing a structure with anisotropy not purely in the transverse in-plane direction such that flux spreading into the transverse in-plane direction can occur by rotation.This method of flux conduction is used in magnetic devices having coupled magnetic layers or coupled magnetic domains. Devices disclosed which utilize this method can function as a magnetic recording head, bubble memory, magnetic field structure, magnetic field sensor, transformer, laminated magnetic memory element or magnetic shield.

Abstract: The magnetic head has poles at each intersection of the matrix of wires. These poles connect the pads of the same column of pads, a gap being defined between the pads of the same intersection of wires and being parallel to the data wire.

Abstract: One aspect of the invention is a method of flux conduction comprising providing a structure with anisotropy not purely in the transverse in-plane direction such that flux spreading into the transverse in-plane direction can occur by rotation. Apparatus includes a thin film magnetic recording device having at least one pole with two magnetic layers and capable of conducting signal flux, a first of the magnetic layers having domains oriented in a first direction, a second of said magnetic layers having domains oriented in a second distinct direction, the layers coupled to each other such that signal flux can flow therebetween. Method of making and various embodiments disclosed.

Abstract: An MR head includes two substantially identical MR elements, separated by an insulating layer which has shorting stubs at its ends for electrically shorting the MR elements. A current applied to the MR elements splits into two currents that flow in the same direction through the substantially identical MR elements, to provide mutual bias and to serve as sense currents for detecting change in element resistance. The MR elements are biased to operate in a magnetically unsaturated mode. This results in a "bootstrapping" of short wavelength signals that effectively amplifies the reproduced signal over a broad region of the signal spectrum when the linear spacing between the MR elements is in the range of from one half to one times the half-wavelength of signals recorded on a magnetic recording medium.

Abstract: A magnetic head affixed to the underside of a carrier body mounted at the periphery of a head-wheel for scanning oblique tracks on a magnetic tape is provided with shielding of ferrite, mu-metal or amorphous iron, to reduce magnetic crosstalk. The shielding surrounds the part of the magnetic head that projects beyond the head carrier body except for a small portion near the polished surface that needs to be left uncovered to avoid interfering aerodynamically with the contact of the magnetic head with a magnetic tape. One piece of the shielding is of rectilinear shallow U-shaped profile, forming a pocket for the magnetic head below the carrier body and extends beyond the tip of the carrier body, where the second piece of shielding material completes an annular shielding ring around the end of the magnetic head. This shielding is particularly useful for an after-check playback head used during recording to check on the quality of the recorded signals.

Abstract: A magnetic head employs a gap of magnetic material between two poles. The magnetic material of the gap has a saturation value less than the saturation value of the poles. When the gap material is not saturated, the magnetic field remains contained within this gap.

Abstract: A self-aligning configuration for establishing precisely where each of any number of tracks is to be recorded on a magnetic tape, utilizes therefor a photosensitive element (of perhaps even coarser structure than that of a given track), the signal output of which constitutes a measure of the location of the track(s). Thereafter, tracking control, say during playback, is pursuant to such signal, which is memorized.

Abstract: In a magnetic head for use in recording and/or reproducing information for a magnetic recording medium, the magnetic head comprising a magnetic core and a non-magnetic slider member, the slider member having a principal surface to face the magnetic recording medium when information recording and/or reproducing are effected for the magnetic recording medium, the non-magnetic slider member is made of a ceramic material essentially consisting of ZrO.sub.2 in order to improve durability and wear-resistance. The ceramic material can contain 27-70% Al.sub.2 O.sub.3 on a base of weight ratio while the balance is substantially ZrO.sub.2. The ZrO.sub.2 can be partially replaced by at least one selected from a group of Y.sub.2 O.sub.3, CaO, and MgO, within a range of 2-17% on a base of molecular ratio.

Abstract: A yoke type thin-film magneto-resistive heat includes a magneto-resistive element that detects the magnetic field generated in the magnetic recording medium as resistance changes, a yoke, that leads magnetic flux from the head gap to the above mentioned magneto-resistive element, a DC magnetic field application system, that applies a desirable weak magnetic field to the above mentioned longitudinal direction of the magneto-resistive element, and a conductor, that applies a desirable bias magnetic field to the above mentioned magneto-resistive element in the strip width direction. The easy axis of magnetization of the magneto-resistive element is inclined in a range of 20.degree.-40.degree. to the mentioned longitudinal direction of the magneto-resistive element, so that, anisotropic angle dispersion conditions are relaxed, at the same time, by applying a desirable bias magnetic field to the magneto-resistive element in the strip width direction.

Abstract: An information storage device includes a magnetic recording medium, preferably supported upon a rotating disk, an electromagnetic writing device that writes magnetic patterns into the recording medium, and a superconducting quantum interference device (SQUID) that reads the magnetic patterns in the recording medium, the writing device and the SQUID preferably being mounted upon a read/write head. The SQUID as operated in its superconducting state is a highly sensitive and directional detector of the magnetic state of the recording medium, permitting it to be spaced relatively distantly from the recording medium yet read the state of small areas of the medium. Use of high temperature superconductors in the SQUID permits practical construction of the information storage device. The read/write head may support a plurality of write devices, and an array of SQUIDs can be utilized so that little or no relative movement of the read/write head is required to read and write from all tracks of the disk.

Abstract: A thin-film optical function element, including a substrate formed of a dielectric material, a first optical waveguide consisting of a thin film of a dielectric material formed on the substrate, and a second optical waveguide consisting of another thin film of another dielectric material formed on the substrate. The first optical waveguide has a substantially same propagation constant with respect to two different modes which have field patterns whose vibrating directions are perpendicular to each other. The second optical waveguide is optically coupled to the first optical waveguide, and is adapted to pass therethrough only one of the two different modes.

Abstract: A vertical recording magnetic head is disposed for movement close to or into sliding contact with a vertical recorded magnetic medium for purpose of magnetic recording and playback. To prevent the influences of external magnetic field upon a recording or reproduced magnetic field, a main magnetic pole of the head is surrounded by a block of a magnetizable material which exhibits a high permeability, which serves as a magnetic shield.

Abstract: In a method of manufacturing a thin film magnetic head having aligned top and bottom pole tip pieces, a sacrificial mask protects the upper pole tip while the exposed non-aligned portions of the gap material and lower pole tip are removed. The sacrificial mask is deposited using a self alignment technique.

Abstract: A thin film magnetic read/write head is electrically grounded. The pole pieces or core of the thin film head is electrically connected to the base substrate of the thin film head. Electrical connection is through a conductive stud extending through a base coat layer and sandwiched between the core and the base substrate of the thin film magnetic read/write head.

Abstract: A magnetic head assembly having a transverse guiding surface which is highly resistant to being abraded by a recording medium for reading and recording magnetically recorded information on the recording medium including a transducer having a transducing element on one end thereof and conductive leads extending from a different end thereof, a substrate formed of a mixture of Aluminum Oxide and Titanium Carbide ("Al.sub.2 O.sub.3 --TiC") having a medium contacting surface and a supporting surface extending substantially perpendicular therefrom wherein the substrate has the transducer rigidly affixed to the substrate supporting surface with the transducing element positioned adjacent the substrate contacting surface, a spacer formed of Al.sub.2 O.sub.

Abstract: A thin magnetic head having a structure which makes it possible to significantly reduce the thickness of the head. First and second nonmagnetic metal plates 2 are fixedly attached to respective opposite sides of two core blocks 1. The intermediate metal plates and core blocks are sandwiched between and fixedly soldered to connecting metal plates 6, to thereby integrate the two core blocks with one another.

Abstract: An arrangement for detecting bank notes having magnetic properties, comprising transport means (11) for transporting documents past a magnetic detector (12-14). The object of the invention is to increase the possibility and the reliability of distinguishing bank notes which are not genuine from genuine bank notes and bank notes of a given denomination/kind from bank notes of another denomination/kind.The detector includes a permanent magnet (12) and a magnetic circuit (13) having detector means (14) for detecting changes in the magnetic field through the magnetic circuit (13). The output side of the detecting means (14) is connected to a signal processing means (20) for generating signals in response to the magnetic properties of bank notes transported through the arrangement.The magnetic circuit (13) includes an air gap (131) which is located closely adjacent the bank note transport path (0--0).

Abstract: An improved form of magnetic erase head is provided which utilizes, in a magnetic erase head, leading and trailing "terminators", which suppress stray fields emanating from leading and trailing magnets.

Abstract: A grooved magnetic substrate including an alumina film layer having a Knopp hardness of 600 kg/mm.sup.2 to 1200 kg/mm.sup.2 charged in at least one groove formed in a surface of a magnetic substrate. The magnetic substrate may be Mn-Zn or Ni--Zn base ferrite. The alumina film layer is formed by sputtering.

Abstract: A reader for a disk-shaped carrier with Wiegand wires is described which manages with only two permanent magnets (1, 2). The variation of the magnetic field needed for detecting the Wiegand wires is effected by flux concentrating pieces (3, 4, 7) attached to the permanent magnets (1, 2). In order to be able to read the carrier with the Wiegand wires without change when it is inserted into the reader rotated by 180.degree. round its longitudinal axis coinciding with the direction of insertion (14), the flux concentrating pieces (3, 4, 7) are arranged symmetrically with respect to the longitudinal axis (14) which is a two-fold axis of symmetry. To pick-up the Wiegand pulses, two E-shaped soft magnetic cores (9) are provided which carry on their center leg an electrical sensor winding (17). The free ends of the legs of the E-shaped cores (9) face one another and are also arranged symmetrically with respect to the longitudinal axis (14).

Abstract: An improved method of manufacturing a thin film magnetic head, which includes the steps of forming an electrically conductive material coil layer on a substrate of a magnetic material, applying onto the electrically conductive material coil layer, an insulation layer of SiO.sub.2, Si.sub.3 N.sub.4, Al.sub.2 O.sub.3 and the like by sputtering, plasma chemical vapor deposition process, etc., and further forming a coating layer of SiO.sub.2 on the insulation layer by spin-coating process for flattening the upper surface of the insulation layer.

Abstract: A recording or reproducing apparatus includes a recording or reproducing head for recording or reproducing information in sliding contact with a rotating flexible disc, and a stabilizer member disposed opposite to the head with the disc put between them. On the stabilizer member, a groove is formed for recessing the moving of the head at the position facing the disc, and on both sides of the groove or on the downstream side in the rotating direction of the disc, a slant is formed for generating positive pressure in the direction of pressing the head to the facing disc. The groove and the slant are formed in conformity with the deformation of the disc due to the sliding contact with the disc.

Abstract: An iron-aluminum-silicon (Fe-Al-Si) series magnetic alloy magnetic head is described. The magnetic head is filled between front gap forming surfaces (the front gap facing a magnetic tape) of a pair of Fe-Al-Si core pieces with non-magnetic ceramic films formed on the respective front gap forming surfaces and a glass film formed therebetween, and between rear gap forming surfaces for junction with an Ag-Cu-In series alloy film.

Abstract: Techniques are described for securing a magnetic head to a support carrier for the head in a magnetic storage device (e.g., a tape drive apparatus or disk drive apparatus). One such technique involves temporarily supporting a magnetic head on a fixture which is adapted to cooperate with openings on the magnetic head to orient the head in a predetermined alignment attitude so that the head may be permanently mounted in the magnetic storage device. In another embodiment the fixture may be part of the magnetic storage device itself. There are also provided various embodiments of magnetic heads having openings for accessing a planar interface between the halves of a magnetic core within the head. By accessing this interface the magnetic head may be aligned in a predetermined alignment attitude.

Abstract: An integrated structure is provided for magnetic recording which utilizes a silicon wafer having two parallel faces which are crystal planes of orientation 100. One face is designed so as to constitute a displacement plane when used as a read and write device in a magnetic support. The magnetic head has a horizontal structure and is integrated into the silicon wafer in the face having the displacement plane. An electronic circuit is integrated in the silicon wafer in one of the two faces and connections are provided between the magnetic head and the electronic circuit.

Abstract: A method of making a thin-film magnetic head having a multi-turn structure includes forming a lower magnetic layer on a substrate, and successively forming a first insulating layer and a first conductive layer over the lower magnetic layer. Then, a first coil patterned mask is formed on the first conductive layer, and an ion beam is applied onto a structure formed by the foregoing steps. The ion beam simultaneously etches the first insulating layer and first conductive layer so that a first coil patterned double-layer is formed. Then, a second insulating layer is formed followed by an upper magnetic layer, over the first coil patterned double-layer. Thus, a magnetic gap is formed between the lower and upper magnetic layers defined by the thickness of the second insulating layer.

Abstract: A thin film magnetic head comprising a thin film magnetic head structure and a protective plate thereon such as glass or the like has an improved bonding interlayer between them. The interlayer is formed by fusing together registered solder areas which have been preformed respectively on the mirror image positions of the upper surface of the head structure and the lower surface of the protective plate.

Abstract: In a magnetic head of perpendicular magnetization type having main and sub magnetic poles arranged at both sides of a recording medium, a nonmagnetic supporter holding a high permeability magnetic thin layer of the main magnetic pole is formed by a polycrystalline sintered body substantially composed of titanium carbide and alumina. This polycrystalline sintered product well matches with a recording medium having a cobalt-chromium alloy layer so that the recording medium does not wear for a long time of use, and therefore, so that the contact surface of the main magnetic pole is hardly damaged. The same sintered body may also be used for the sub magnetic pole arranged to be in contact with the recording medium. Some structural improvements are also provided so that undesirable influence due to an adhesive layer adjacent to the magnetic thin layer is removed. One or more additional thin layers may be provided for reducing crosstalk between adjacent tracks.

Abstract: A magnetic head integrally assembled with a step-up transformer. The magnetic head portion is formed on a lower substrate by a thin film technology and the number of turns of the signal winding is 1 or a value near 1. The transformer portion mainly comprises a transformer magnetic circuit which is formed by the lower substrate and upper substrate. A one-turn primary coil of a thin film formed over the lower substrate and a secondary coil by a bulk wire are arranged so as to couple inductively with each other through the transformer magnetic circuit. The signal winding and the primary coil winding are formed by the same thin film process. The head portion and the transformer portion thus are arranged very closely and hence coupled with very little transfer loss of signal.

Abstract: A grooved magnetic substrate including an alumina film layer having a Knoop hardness of 600 kg/mm.sup.2 to 1200 kg/mm.sup.2 charged in at least one groove formed in a surface of a magnetic substrate. The magnetic substrate may be Mn-Zn or NiZn base ferrite. The alumina film layer is formed by sputtering.

Abstract: The present invention relates to a magnetic head, which can form guard bands on a magnetic recording medium and which is especially suitable for magnetic discs, and a fabrication process thereof. The magnetic core of the present invention includes a recording and reproduction head core (31) and an erasure head core (32) which is integrally joined in series to the head core (31) for forming guard bands. Magnetic circuits are constructed of metallic magnetic materials (34), (34'), (35) and (35') formed on non-magnetic members (33) and (33'). As a result, a recording medium having high coercive forces can be recorded while the track width is reduced and the fabrication is facilitated with a high accuracy.

Abstract: An improved thin film magnetoresistive (MR) sensor uses an alloy comprising Fe, Mn and Cr as an antiferromagnetic layer to provide a longitudinal exchange bias in the ferromagnetic MR layer. Sufficient exchange biasing is provided and the FeMnCr layer exhibits excellent corrosion resistance.

Abstract: A thin-film, cross-field, closed-flux, anisotropic electromagnetic field device for recording images on and reading them from magnetic media, such as a magnetic disk, tape or drum. The device is characterized by two orthogonally related conductors which couple electromagnetically with magnetic coupling structure. One portion of such structure substantially completely surrounds one of the conductors relative to the direction of current flow therein, this portion being anisotropic, and having an easy axis of magnetization that parallels such current flow. With the device in use, this easy axis is intended for operative coupling alignment normally relative to the recording surface in the selected recording medium.

Abstract: Techniques are described for securing a magnetic head to a support carrier for the head in a magnetic storage device (e.g., a tape drive apparatus or disk drive apparatus). One such technique involves temporarily supporting a magnetic head on a fixture which is adapted to cooperate with openings on the magnetic head to orient the head in a predetermined alignment attitude so that the head may be permanently mounted in the magnetic storage device. In another embodiment the fixture may be part of the magnetic storage device itself. There are also provided various embodiments of magnetic heads having openings for accessing a planar interface between the halves of a magnetic core within the head. By accessing this interface the magnetic head may be aligned in a predetermined alignment attitude.

Abstract: A probe head for vertical recording includes a U-shaped member partially surrounding the probe and a coil supported by the U-shaped member. When the coil is energized, flux from the probe is focused to the region between the legs of the U-shaped member to greatly increase flux gradient during a write operation.

Abstract: In a magnetic head of perpendicular magnetization type having main and sub magnetic poles arranged at both sides of a recording medium, a nonmagnetic supporter holding a high permeability magnetic thin layer of the main magnetic pole is formed by a polycrystalline sintered body substantially composed of titanium carbide and alumina. This polycrystalline sintered product well matches with a recording medium having a cobalt-chromium alloy layer so that the recording medium does not wear for a long time of use, and therefore, so that the contact surface of the main magnetic pole is hardly damaged. The same sintered body may also be used for the sub magnetic pole arranged to be in contact with the recording medium. Some structural improvements are also provided so that undesirable influence due to an adhesive layer adjacent to the magnetic thin layer is removed. One or more additional thin layers may be provided for reducing crosstalk between adjacent tracks.

Abstract: A pulse generating unit in which a Wiegand wire module is contained within two soft iron ferromagnetic members which act as shunts in that they collect, conduct and guide flux incident on the pulse generating unit toward an air gap between the two shunt elements. the air gap is approximately at the center of the Wiegand wire module. Cylindrical cavities in these two shunt elements shield the ends of the Wiegand wire thereby minimizing the incidence of external flux on the Wiegand wire. Saturation of the flux at the air gap between the two shunts causes leakage of flux to be available to switch the state of the Wiegand wire.

Abstract: In a magnetic head having magnetic cores for performing recording and/or reproducing and erasing of information onto and/or from and from a magnetic recording medium and a slider for supporting the cores, a member for shielding the magnetic cores magnetically is provided in the slider. When accessing information by sandwiching a magnetic recording medium between the two opposing portions of a pair of the magnetic heads, crosstalk is reduced between the magnetic cores and thus recording and/or reproducing errors are prevented. The reliability of the magnetic head is improved.

Abstract: An inductive pulse generator for converting a rotary movement into a frequency proportional therewith. The pulse generator includes a measuring wheel (1) provided with poles (3) of magnetic material evenly distributed over the circumference of the measuring wheel. The pulse generator further includes a stator (4) provided with a magnetic core (6) with plate-shaped pole shoes (10) in a coil carrier (8) out of which end portions (12) of the pole shoes (10) project. The end portions (12) face the measuring wheel (1). A coil (7) surrounds the magnet core (6), at which coil (7) a pulsating voltage can be picked off with a frequency proportional to the number of revolutions of the measuring wheel (1), outside the area of the pole shoe (10) end portions (12) facing the measuring wheel (1). The thickness of the pole shoes (10) is increased by additional magnetic material (11) so as to increase the pulsating voltage which can be picked off at the coil (7).

Abstract: A magnetic head device for use with a disc-shaped magnetic recording medium, for example, includes a thin-film magnetic recording and reproducing head and a biasing magnetic head mounted in a positioning member for applying a magnetic field to the magnetic recording medium in a signal recording mode. The biasing magnetic head is positioned in confronting relation to the thin-film magnetic recording and reproducing head with the magnetic recording medium interposed therebetween.

Abstract: Slant gap magnetic heads, comprised of back-to-back wedges, are produced by an inventive procedure: Bars of discrete coil-wound thin-film heads--which bars are, cross-sectionally, L-shaped--are stacked with respect to each other. By dicing through the stack of bars at an angle commensurate with the degree of gap-slant, discrete slant gap head structures are produced. With minimal contouring/lapping, such head structures may be finished for use in recording equipment that records chevron-like alternating skewed information tracks.

Abstract: A thin layer magnetic head comprising a ceramic substrate consisting essentially of 100 parts by weight of a ceramic material and 0.05 to 5 parts by weight of at least one compound from the group consisting of silicon oxide and iron oxide.

Abstract: An apparatus for reproducing a signal recorded, in the form of a perpendicular signal magnetization, on a perpendicular magnetic recording layer backed with a high permeability layer of a magnetic recording medium. A thin-film magnetic material is disposed to face the recording layer so that an enlarged magnetized region is formed in the high permeability layer, which includes the position at which the magnetic material faces the recording layer. In this region, magnetic variation occurs in response to the signal magnetization of the recording layer at the position the magnetic material faces the recording layer. A detecting member such as a coil is disposed in the proximity of the magnetic material so as to be magnetically coupled to the enlarged magnetized region of the high permeability layer. The detecting member is used as a tuning element of a tuning circuit supplied with high frequency energy.

Abstract: A thin magnetic film is deposited over a nonmagnetic or piezoelectric substrate. When a shock wave is propagated through this substrate from its one end to the other end, the permeability of the thin magnetic film is locally increased and a portion or region having a high permeability also travels from one end to the other end of the thin magnetic film in unison with the shock wave. A magnetic core with a signal winding is disposed and magnetically coupled with the thin magnetic film. The signal can be recorded or reproduced while the recording medium is scanned.

Abstract: An electrical lapping guide resistor for measuring the lapping distance in a process for manufacturing thin film magnetic transducers. Final throat height is measured with an electrical lapping guide resistor which provides a linear change in resistance versus lapping distance. The lapping guide resistor is configured in a shape such that the effective length of the resistors increases as the effective width decreases. In a preferred embodiment of the invention, the resistor includes first and second converging edges which extend from a rearward edge parallel to the final throat height toward the lapping surface. Conductors are disposed along the converging edges. Measurements of the change in lapping distance are effected by measuring the distance between the conductors.

Abstract: A non-magnetic part bonded to a magnetic core portion made of Ni-Zn ferrite in a magnetic head assembly which is made of a ceramic material comprised of 30 to 50 volume % of TiO.sub.2 and 70 to 50 volume % of Ba.sub.2 Ti.sub.9 O.sub.20 and BaAl.sub.2 Ti.sub.5 O.sub.14 wherein the volume ratio of Ba.sub.2 Ti.sub.9 O.sub.20 to the total volume of Ba.sub.2 Ti.sub.9 O.sub.20 and BaAl.sub.2 Ti.sub.5 O.sub.14 is 0.05 to 0.5.

Abstract: In a magnetic head which utilizes the magnetoresistive effect of a ferromagnetic thin film, it is possible to realize a magnetoresistive effect type thin film magnetic head with favorable secondary distortion characteristics by forming on at least one surface of the ferromagnetic thin film, a grating forming an angle larger than 60.degree. and smaller than 80.degree. with respect to the direction of the electric current flowing through the thin film. By setting the grating into more than two different directions, a magnetic head capable of functioning at a still smaller distortion is presented.