Abstract: A magnetic head is manufactured by depositing a layer of spacer material onto the facing surfaces of the magnetic cores; the thickness of each layer being approximately one-half the length of the intended gap and the thicknesses of both layers together being approximately equal to the thickness (length) of the gap. A layer of bonding glass is deposited onto the surfaces of the spacer layers and the cores are pressed together at an elevated temperature to fuse the glass layers and extrude most of the glass.

Abstract: In a magnetic erasing head having a first gap and a second gap formed respectively between ferrite cores, one or more magnetic material layers (Fe-layers) are arranged in the gaps respectively, and the magnetic material layers have the magnetic flux density (B.sub.10) of more than 5000 gauss, the permeability of more than 5000 and the thickness of 5.mu. to 30.mu..

Abstract: A magnetic head assembly includes read/write pole elements having tip structure flush with slide surfaces on separate mounts, the latter mounting erase poles having ends at opposite sides of the read/write pole tip structure. Separate coils may be located about the erase poles; and notches may be located in the mounts at opposite sides of the read/write pole elements to provide a controlled throat dimension.

Abstract: A construction of a multi-track read and write head assembly is disclosed in which conductive shielding elements are interconnected with low resistance conductive paths by means of electrically conductive layers plated onto the shielding elements.

Abstract: A track servoing system is disclosed which is particularly useful with floppy disk memories. The system improves the positioning accuracy of a read/write head during a reading operation through the use of tunnel erase heads as read heads. The tunnel erase heads are positioned on either side of the read/write head and their outputs are differentially measured to provide direction and magnitude information to servo positioning electronics. The invention is particularly reliable in reading eccentric variations in data tracks caused by environment, i.e., humidity, temperature, etc.

Abstract: A single magnetic head assembly having vertically stacked separate units of recording and playback cores is comprised of a first unit of at least one recording cores, and a second unit of at least one playback core which is located in stacked positional relationship relative to the first unit. These units of cores are arranged to be jointly shifted vertically to meet the required track of the magnetic tape when used, to thereby utilize that particular unit of cores optimum for recording or playback, as desired.

Abstract: High track density multitrack magnetic heads are batch-fabricated from a stack of wafers which are photolithographically processed to provide lands and grooves on the wafers. Thin magnetic films are deposited in the grooves; and coils respectively inductively cooperative with the films are photolithographically formed about the films, the lands serving both to provide track-to-track spacing and to protect the magnetic films from magnetostriction-producing stress.

Abstract: A magnetic head assembly for cooperating with a relatively moving medium, on which servo information and data information is recorded, and for reading and/or writing on said medium and for erasing said medium is fabricated so that the effect of pickup interference or unwanted signals during playback is reduced. The magnetic head assembly incorporates a geometry which shifts the signal envelope of the interfering signal so that it is in phase with the signal envelope of the desired signal. The preferred geometry is to dimension the head core so that the distance between two gaps or between a single gap and the edge of the core is equal to the distance between the servo tracks on said medium. Additionally, the gap of the head has a gap null occurring at the frequency of the interfering signal.

Abstract: An arrangement for recording information on a magnetic record carrier, having at least one magnetic recording head which incorporates an electromagnet having a core, wherein said arrangement includes a magnetic shunt, said magnetic shunt and the magnetic core of the electromagnet being adapted to be arranged on either side of said record carrier and close thereto, so as to form a closed magnetic circuit in which the magnetic flux is substantially perpendicular to the surface of the carrier, the said core having a recording pole and a flux-closing pole and the cross-section of the recording pole being smaller than that of the flux-closing pole.

Abstract: In a magnetic head having a tape contact face, a non-ferromagnetic unitary housing has a cavity for receiving a coil and has a slot for receiving at least one C-core of the magnetic circuit. The slot extends in a side face of the housing and debouches at one end into the cavity and at the other end into the tape contact face.

Abstract: A data storage retrieval system includes a magnetic circuit read head which comprises first and second pole members. Located and positioned between the poles is a pickup means which comprises a magnetic member having a pickup coil associated therewith. The member as positioned between the poles is located at a point which provides zero output across the coil when the poles are excited by a source of alternating potential. A magnetic material which may be positioned on an information carrying card is positioned such that it affects the flux lines between one of the poles and said pickup means. This position of the magnetic member serves to provide a signal across the coil indicative of a binary one or a zero.

Abstract: Apparatus for reproducing magnetically recorded information comprise first and second reproduce heads for reproducing magnetically recorded information from a magnetic recording channel alternatively at first and second tape speeds. These reproduce heads include spaced pairs of matching pole pieces defining air gaps, and spacer elements between these pairs of matching pole pieces. The pole pieces and spacer elements are bonded into a solid unit by a bonding material filling the air gaps and bonding the pole pieces in each pair, the spaced pairs and the spacer elements to each other. Magnetic yokes are magnetically coupled to the bonded pole pieces and electromagnetic windings are magnetically coupled to the yokes.

Abstract: A composite magnetic head including a record/playback gap and an erase gap comprises a straight central core, a pair of arcuate lateral cores having their ends disposed in opposing relationship with the opposite ends of the central core disposed therebetween, each of the lateral cores being formed with a bobbin carrying portion at its one end which extends in a direction perpendicular to the length of the central core, a bobbin having a central flange and a pair of flanges at the opposite ends, the central flange being formed with an opening for receiving the central core and the bobbin being formed with a slot extending through the entire length of the bobbin including the flanges at the opposite ends for receiving the lateral cores, the slot extending in a direction perpendicular to the opening which receives the central core, and a pair of coils disposed between the central flange and the respective end flanges, the central core and the lateral cores forming a record/playback gap and an erase head at their

Abstract: A transducer core having a magnetic core defining a non-magnetic gap and being integrally joined with a superposed composite body. The composite body has a nonmagnetic front portion spanning the nonmagnetic gap and a contiguous magnetic back portion. The superposed core and body are provided with overlapping grooves forming a window adapted to receive transducer windings.A method of manufacturing a magnetic transducer is provided wherein two complementary blocks of magnetic material are bonded together to define a nonmagnetic gap therebetween. A confronting surface of one of the blocks is grooved prior to bonding. The resulting magnetic block is sliced into a plurality of magnetic cores. A second magnetic block is provided with a longitudinal groove along one side thereof which side is bonded to a nonmagnetic block. The resulting composite block is sliced into a plurality of composite bodies, each comprising a nonmagnetic front portion and a magnetic back portion.

Abstract: A head chip having a track width of a gap smaller than a thickness of a core enables a high density recording of a video signal. The track width of the gap is machined before a bulk is sliced into individual head chips to save manufacturing time and enhance yield. An efficient machining of the track width is achieved using a plurality of hard metal wires such as piano wires spanned on rollers each having a plurality of precisely spaced grooves thereon and reciprocating the metal wires while dropping grinding liquid thereon. In this manner, the occurrence of chipping of core material is minimized or the size of chipping, if any, is minimized.

Abstract: A magnetic head or transducer assembly for cooperating with a relatively moving magnetic medium and for reading and/or writing a track of magnetic information on the medium and for erasing the edges of the track and old information adjacent to the edges of a newly written track. The head comprises a central magnetic core with a gap on an active face of the head assembly and with a read/write coil on the magnetic core and comprises a pair of additional, erase magnetic cores on opposite sides of the central magnetic core and forming a pair of erase gaps on the active face of the head assembly. A single erase coil is disposed on opposite legs of the erase cores, and an L-shaped side bar completes the erase magnetic circuit for both of the erase cores and lies on one end of the erase coil and provides an air gap between it and the ends of each of these erase core legs so as to cause the action of the two erase gaps to be equal in their erasing action.

Abstract: A magnetic head for use with a tape recorder or the like comprises a core having a gap and which has a non-magnetic material of a similar mechanical property as the core material bonded to the periphery or part thereof, thereby preventing a foul-up of the head surface with dusts and avoiding damage to the magnetic tape; the foul-up or the damage occurs when the periphery of the core is filled with a layer of synthetic resin adhesive.

Abstract: Magnetic ink characters on a document 1A are sensed by a single gap magnetic reading head which employs a segmented linear array having adjoining magnetic sensing elements. Each sensing element is a C-shaped laminated core with the reading head comprising an array of contiguously aligned cores where the core gaps are on an axis perpendicular to a document travel path. A pickoff coil encircles the vertical member of one arm of each laminated core and pickoff coils for juxtapositioned sensing elements are staggered on either side of the core gap so that no two coils are immediately adjacent. A chrome over copper plate about the core gaps is employed to improve the read head wear life and narrow the side-view angle of the sensing elements. The resolution and signal to noise ratio of the sensing element responses thereby is improved.

Abstract: A bias conductor layer for a bias current path extends through the gaps of a plurality of unit thin-film magnetic heads, which are placed side by side over signal conductor layers. A spacer layer is provided between upper and lower magnetic material layers and extends over the area including the gaps formed between the bias conductor layer and the signal conductor layers, and an additional thickness of spacer material is provided at the gaps so that the distance between the upper and lower magnetic material layers is increased and therefore magnetic short-circuiting is avoided.

Abstract: A thin-film magnetic head having improved playback properties in which the gap-bounding core parts overlap each other laterally while enclosing a layer having a gap and in which a first core part has the shape of a closed loop and is bridged in the center by a second core part. The parts of the first core part on either side of the bridge are provided with identical coils, while the first core part at the area of the overlap is divided centrally by an extra gap. Upon playing back, the difference signals of the coils then provides an indication as regards the position relative to the track.

Abstract: In a magnetic head comprising a write-in excitation core and a read-out excitation core having a narrower track width than that of the write-in excitation core and forming a closed magnetic circuit with a gap interposed between the two cores, a non-magnetic spacer having thickness 1.5 to 5 times as great as the width of the gap is disposed at one or each end of the read-out excitation core with respect to the widthwise direction of the track thereof, and a dummy core is disposed adjacent to the read-out excitation core with the non-magnetic spacer interposed therebetween to form a closed magnetic circuit with the gap interposed between the dummy core and the write-in excitation core.

Abstract: The front face of a multitrack magnetic head has a stack of track defining pole pairs and spacers between the pole pairs of adjacent tracks. The spacers are slotted, and shields reside in the slots. A chamfer runs longitudinally of the stack. Embracing opposite sides of the stack and parallel to the chamfer, are non-magnetic wing parts, such parts being part of a surround used in the manufacture of the front face. Bonding glass, in the form of a unitary "lattice" fills the chamfer, and the spacings between the ceramic and shields, and the wing parts and stack.The method for forming the head employs a surround having a depth greater than the depth of the stack, thereby forming a basin for accepting the bonding glass.

Abstract: A multi-element magnetic head having a plurality of magnetic heads, in which a common electrode common to the coils of the individual heads is provided. By this construction the number of electrodes is reduced and also the area required for contact between leads from an external circuit and electrodes are reduced. Thus, it is made possible to reduce the head pitch of the magnetic heads.

Abstract: A transducer particularly for use with magnetic record disks and composed of cores having transducing gaps therein adapted to contact or be in near contact with a record disk at the gaps an composed also of outriggers on the sides of the cores for increasing the surface area of the transducer adapted to contact or be in near contact with a record disk. The cores are of ferrite and have windings thereon, and the outriggers are of ceramic, both the ferrite and ceramic being nonconductive electrically. One of the outriggers is provided with a plating of electrically conductive material on a side surface with the plating being coterminous with the surface of the outrigger adapted to contact the record disk or be in near contact with it, and a ground lead is connected with the plating so as to ground any electrostatic charge on the surface of the disk.

Abstract: Magnetic head positioning and playback apparatus is provided for use with a helical scan tape recorder to accurately position a playback head with respect to a magnetic track. The playback head has a split face portion dividing the playback gap substantially in half. Reproduce signals from the corresponding portions are simultaneously processed to provide an indication of positional error and summed to provide a playback signal. In one form, by differencing the reproduce signals from the corresponding portions and by multiplying the difference and sum signals together, a usable correction signal is provided to a servo circuit for simultaneously centering the head on the track while reproducing a playback signal -- this being accomplished without the use of a separate control track.

Abstract: A narrow track width magnetic head can be formed using an integrated circuit formation techniques such as evaporation plating, chemical etching, etc. But, there has been such a problem that it is difficult to provide a center tap in a conventional thin film magnetic head structure including coils of four or more turns. A magnetic head according to the present invention comprising a coil divided into two sections by the center tap, the electrostatic capacitance of each section being substantially the same. The coil may be formed into a precise pattern with ease by photoetching technique. A plurality of sets of conductive films insulated from one another are provided crossing a magnetic core, each set consisting of two conductive films of the same pattern. The alternating layers of the conductive films are connected on the backward of a magnetic gap to provide the two sections of the coil.

Abstract: In the manufacture of a transducer head, a plurality of elongated slots are formed in a non-magnetic substrate to receive magnetic cores having a transducing gap. A sealing composition bonds the cores in the slots and the cores are then laser trimmed to predetermined widths and at predetermined core-to-core spacings.

Abstract: The invention provides a structure for a read-only integrated magnetic head which, without any recourse to a shield, ensures or at least enables the elimination from the read-out signal transferred from the head to the external circuits it must feed, any component which might be due to the application of spurious electromagnetic fields to the surface comprised by the flat conductor winding coil and to the surface intervening between the output leads of said coil up to the rear edge of the substrate which carries the integrated magnetic head.An additional flat conductor winding coil is provided over the read-out coil. Said two coils register but they are mutually magnetically decoupled, by means for instance of an intervening non-magnetic dielectric layer of appropriate thickness.

Abstract: A recording head array for magnetic printing machines comprises a flat sheet pole spaced from a line of magnetic pin poles. Spaces between image elements recorded by adjacent poles are thereby reduced. The sheet pole may be magnetized to provide a direct current bias field.

Abstract: A plurality of thin-film transducer chips are mounted on a flying head. The head is mounted adjacent a magnetic storage medium having a plurality of closely spaced tracks. Each of the transducer chips has a transducer adjacent a corresponding one of each of the tracks of the storage medium so that a plurality of transducers may be used for reading or writing on each of the tracks. A specially designed write transducer may be used to write on each track and another specially designed read transducer may be used to read from each track.

Abstract: A multitrack recording head having a pair of ferrite combs whose teeth are separated at their tips by nonmagnetic gap spacers and whose bases are in abutting relationship. Each tooth of one comb has a wire coil for electrically transmitting signals to or from each track of the head.

Abstract: A multi-tracks magnetic head has a first conductor utilized as the bias winding, and a second conductor as the winding for the signal to be recorded. Only the first conductors of the respective unit magnetic heads are connected in series.By making use of the multi-track magnetic head constructed in this way, electrical power consumption by the amplifiers supplying the recording currents to drive all the composing unit magnetic heads is minimized, and the magnetic cross-talk between the unit magnetic heads is reduced.

Abstract: Apparatus for increasing the density of data tracks on the recording surfaces of a disc memory of the type having at least one pre-recorded servo track which is continuously read by a servo head whose output signal changes with its position relative the track and is constantly adjusted to maintain a predetermined servo head output signal condition, without increasing the number of servo tracks in the memory. The improvement comprises a servo head having a plurality of flux paths, each passing through a signal winding, and having adjacent read gaps arranged and spaced such that by successively employing one or another of the read gaps to sense a servo track, the number of data tracks can be increased by an integer multiple.

Abstract: A multi-channel dual-gap magnetic head. The head has a plurality of magnetic head tips which are separated magnetically from each other by non-magnetic materials, and each having two magnetic gaps. A plurality of magnetic back cores are connected to said magnetic head tips, and a plurality of windings are wound on the respective back cores. The corresponding magnetic gaps in the head tips are aligned in two straight lines which are parallel to each other and perpendicular to the direction of tape movement of the tape for a recording and reproducing device. The magnetic gaps aligned in one straight line have at least two different gap widths for carrying out different functions from among the functions of recording, playback and erasing.

Abstract: In a thin film magnetic writing head structure, a high permeability layer is arranged parallel to the lateral face of a pole piece which is situated in the downstream direction of movement of the magnetic record carrier under the head airgap. Said high permeability layer is magnetostatically de-coupled from the pole piece. This arrangement guides the zero magnetic field lines from the head along the frontal plane of the pole piece and along the lateral face of said piece, thereby drastically reducing the action of de-magnetizing components of the writing flux on the record.

Abstract: A magnetic recording and reproducing head is provided for use in cassette applications. The head comprises a pair of tracks and is constructed such that the reading gap assigned to the first track is aligned with the recording and erasing gap assigned to the other track, the tracks being arranged reciprocally.

Abstract: A magnetic head assembly and the method of manufacture therefor comprising a generally cylindrical housing having a tapered portion at one end thereof terminating in a circular aperture having an inner diameter, a circular slider body having an outer diameter slightly less than the inner diameter, a media engaging surface and an internal surface and being disposed within the circular aperture and affixed to the housing. The body also includes a first elongated slot disposed along a first diameter and extending through the body, a second slot disposed along a second diameter normal to the first diameter and extending into the body from the internal surface, and a central aperture extending through the body at the intersection of the first and second slots. A read/write transducer has a pair of read/write pole pieces which are separated to provide a read/write gap and which extend into the first slot with the read/write gap positioned with the central aperture.

Abstract: A document positioning device is provided having a document holder or carrier which is driven by a stepper motor to position a document clamped therein for printing thereon. A row of light sources, e.g. light emitting diodes (LEDs) are pre-positioned and spaced along the path of travel of the document holder so that each source corresponds to a line to be printed on the document. A photosensor is mounted on the document holder for scanning the LEDs. The LED is lit for the selected line to be printed and the stepper motor moves the document holder, scanning the LEDs until coincidence occurs, stopping the motor. A memory is coupled to the motor control circuit of the stepper motor which is activated on coincidence to force the motor control circuit into the proper output for a selected line. For manual operation the LEDs are continually cycled, and the document holder manually moved to the selected line with the power to the motor off.

Abstract: A real time conversational student response teaching apparatus comprising a magnetic storage medium, such as a tape, having a plurality of audio tracks having audio information stored thereon for selective playback therefrom. The storage medium contains information stored on each track in a plurality of reproducible information segments, each of which comprises a complete message which is reproducible directly in response to the selection of the track upon which the segments are stored. One of the tracks, preferably a centrally located track having a greater track width than the others, contains interrogatory messages and associated multiple choice selectible responses to a particular interrogatory message while a plurality of the other tracks contain responsive messages related in real time and content to the interrogatory messages in a conversational real time environment.

Abstract: A credit card reader is described which includes two magnetic readout heads whose gaps are spaced from each other a distance equal to one half the distance between adjacent, uniformly spaced bits of binary coded information. The coded data is recorded on a linear length of the credit card. The two similar sets of signals are extracted, one delayed relative to the other, as the heads scan the data. Decoding circuitry is described which provides information corresponding to the recorded data independently of the relative speed at which the credit card is moved or is swept past the readout heads.

Abstract: The present invention relates to a magnetic recording head and specifically the back bar of a multi-channel magnetic recording head for use in high performance multitrack disc files. Crosstalk is substantially reduced by incorporating a specially shaped back bar, such as a back bar having an L-shaped cross section to enclose and reduce the crosscoupling fringing fields from the back gaps. In addition, the use of an epoxy with a magnetic filler material is included to further reduce the back gap fringing fields. The above-mentioned techniques when used in combination with a limited dimension intertrack shield can greatly reduce the crosstalk between cores of a high track density flying head.

Abstract: Described is a magnetic transducer head assembly provided with a wear indicator to produce an indication when the head wear has proceeded to a predetermined point. For this purpose, the magnetic shield of the head includes a portion aligned with the pole faces of the head and which portion is subject to wear with the pole faces, such that the electrical continuity of the magnetic shield is interrupted upon the occurrence of a predetermined amount of wear of the pole faces. The magnetic shield further includes terminals for connection to an electrical device to test the electrical continuity of the shield portion, and thereby to provide an indication of the occurrence of the predetermined amount of wear.