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: In a magnetic disk memory comprising a disk pack hub seated at both sides in ball bearings in a housing, the ball bearings are tensed in the actual direction relative to one another in order to achieve a play-free hub guidance. To this end, at least one housing wall is resiliently designed in the direction of the hub axis and flexes upon the application of a restraining force. Before integration into a completed memory unit, the spacings of the inner rings of the ball bearings, tightly seated on the hub shaft, and of the bearing locations in the housing which accept the outer rings with an interference fit, deviate slightly from one another.

Abstract: A loading and ejection mechanism includes an inversion gear rotated by a motor in the opposite directions, an eject plate having a rack engageable with the inversion gear, and a mechanism to bring the rack into engagement with the inversion gear, so that the eject plate is moved back and forth by rotation of the inversion gear during loading and ejection so as to move a pack guide up and down and move an eject arm back and forth.

Abstract: A tape loading/unloading arrangement for use in a magnetic recording and/or reproducing apparatus, such as an 8 mm video cassette recorder, includes a pair of tape guides which pull a portion of a tape out of a tape cassette so as to extend it around a tilted guide cylinder. An improvement is made to the tape guide which comprises a support plate, an upright post perpendicularly mounted on the support plate, a slanted post mounted on the support plate adjacent the upright post for movement closely adjacent a surface of the guide cylinder, and an auxiliary post movably mounted on the support plate and adapted to be located, during the movement of the support plate between home- and operating-positions, in front of a common tangent face to the upright post and the slanted post, which common tangent face is located on the side of said upright and slanted posts facing the operating-position, but is located, when the support plate terminates at the operating-position, behind the common tangent face.

Abstract: In a magnetic head for perpendicular magnetization recording of a main magnetic pole exited type, a high permeability magnetic thin layer is held at its top portion by nonmagnetic supporter and the thin layer is closed by a first high permeability block. The thus constructed main magnetic pole is surrounded by a second high permeability block, and a third high permeability block is located in facing relation to the main magnetic pole and second high permeability material. This magnetic head has high recording and reproducing efficiency and well-shielded from external magnetic field. Some structural improvements are also provided so that leakage of magnetic flux, disconnection and short circuit of a coil are avoided.

Abstract: A core of a soft-magnetic material with a comparatively low saturation magnetization has layers of a soft-magnetic material with a higher saturation magnetization on the gap-bounding faces. To compensate for the uneven frequency response cause by the non-magnetic transition zones between the material of the core and the layers of soft-magnetic material, the layers of soft-magnetic material on the gap-bounding faces have different thicknesses.

Abstract: Tape-to-head compliance in a bidirectional magnetic tape drive is substantially improved in both directions by pivotally mounting the pressure pads. Friction between the moving tape and the pressure pads causes the pads to rotate slightly, the leading portions of the pressure pads thereby exerting greater pressure on the tape than the trailing portions.

Abstract: A magnetic disk storage device capable of avoiding the occurrence of vibration of magnetic disks and off-track of magnetic heads with respect to the magnetic disks, including an inner shroud enclosing a disk assembly composed of a multiplicity of magnetic disks stacked in superposed relation with spacers being interposed therebetween and formed at its outer peripheral wall with first ports for inserting access arms therethrough and at its top above a spindle supporting the disk assembly with a second port, a cylindrical filter for removing dust from air flowing through the second port of the inner shroud into the interior thereof, and a dust cover enclosing the inner shroud, actuators and filter. The provision of the inner shroud is conductive to prevention of development of turbulent air flow in the vicinity of the magnetic disks.

Abstract: A disc cassette comprising an information disc has a slot 10 for the passage of a recording and/or reproducing head and a central opening 9 for the passage of a drive spindle. On the outside it carries a closing cover which is movable towards an operational position and which has a slot 12 which aligns with the slot 10 in the envelope in the operational position of the closing cover. The closing cover 11 extends further than the central opening 9 in the major wall to cover this opening in the closing position of the closing cover and has a further opening 13 which overlaps the central opening in the envelope of the disc cassette in said operational position to allow the passage of drive spindle of a drive apparatus. Preferably the closing cover and the envelope cooperate with each other near the central opening to retain the closing cover against undesired displacements away from the enclosure.

Abstract: A magnetic head mounting device of a magnetic recording apparatus including a carriage, a first magnetic head supported by the carriage, a head arm supported by the carriage for movement in a vertical direction, and a second magnetic head supported by the head arm and disposed in spaced juxtaposed relation to the first magnetic head, wherein both or one of the first magnetic head and second magnetic head is mounted on the carriage or head arm through a gimbal. The gimbal includes a head mounting section for mounting the first magnetic head or second magnetic head thereto, and a supported section disposed outwardly of the head mounting section and partly supported by projections located at the carriage or head arm, the head mounting section and supported section being partly connected together through a plurality of connections.

Abstract: A magnetic disc memory device comprises a rotatable member, a stationary member for supporting the rotatable member, dynamic pressure bearing provided between the stationary member and the rotatable member, a plurality of information recording magnetic discs mounted in axially spaced apart relationship on the outer peripheral portion of the rotatable member, an annular rotor provided on the outer peripheral portion of the rotatable member in axially spaced apart relationship with the magnetic discs, an annular stator secured to the stationary member and radially facing the annular rotor, the stator and the rotor together constituting an electric motor, and a case secured to the stationary member and surrounding the magnetic discs, the rotatable member, the rotor and the stator to protect them from extraneous influence.

Abstract: A cassette cover opening mechanism has a cassette cover opening member for opening the cassette cover of a tape cassette when the cassette is loaded in a video tape recorder. The opening member has a first abutment portion and a second abutment portion. The first portion abuts against the lower edge of a front plate of the cassette cover to pivot the cover during a first half of the movement of a cassette holder from its first position to its second position. The second portion abuts against the lower edge of one of side plates of the cassette cover to further pivot the cover during a latter half of the movement of the cassette holder.

Abstract: A rotary encoder comprises a case containing a rotary brush setting plate and an idler gear which is associated with an inside gear formed on the brush setting plate and a reduction gear contained in the case and connected to a driving shaft penetrating the case. Brushes on the rotary brush setting plate rotatingly slide on the plural pulse producing conductive patterns formed on inside surface of the case, thereby to effect switching in plural modes as the shaft revolves.

Abstract: An automatic tape loading type recording and/or reproducing apparatus comprises a guide drum having one or a plurality of recording and/or reproducing heads for recording and/or reproducing a signal on and/or from a tape, first and second loading members which relatively enter within a tape cassette which is loaded into the apparatus, a first loading mechanism for moving the first loading member over a short distance so as to draw the tape out of the loaded tape cassette and wrap the tape around a peripheral surface of the guide drum, a second loading mechanism comprising a rotatable loading ring mechanism which is disposed to encircle the guide drum, for moving the second loading member along the peripheral surface of the guide drum in a direction opposite to the moving direction of the first loading member so as to draw the tape out of the loaded tape cassette and wrap the tape around the peripheral surface of the guide drum, and a control mechanism for controlling an operating timing of the first loading m

Abstract: Given a medium comprised of a vertically recordable underlying region of a magnetic material and a cooperating overlying region of horizontally recordable material, the invention calls for the pre-recording of such tracking information, in the underlying region, that between adjacent tracks there occurs a vertically disposed flux reversal in the underlying region, each such track being approximately the width of a playback core disposed to read data recorded in the overlying region. Deposited on the side face of the playback core, in accordance with the invention, is a magneto-resistive element. So long as the playback core is on-track, the magneto-resistive element "sees" equal vertical fields on either side of the track edge; but should the playback core start to mistrack, the magneto-resistive element will see vertical flux of one or another polarity.

Abstract: In a recording and reproducing device for a magnetic disc, including a carriage supporting a magnetic head, an engaging piece secured to the carriage, and a screw threaded shaft engaging with the engaging piece for causing a linear shift of the carriage, the screw threaded shaft is formed with a plurality of groove portions. Each of the groove portions has a substantially linear groove bottom of a leading angle substantially equal to 0.degree.. The groove portions are arranged in an equally spaced apart relation around the surface of the shaft so that the portions are mutually displaced in the axial direction of the shaft by a predetermined distance, and that when these are connected together, a kind of helical groove is formed around the surface of the shaft. To be cooperative with the helical groove, the engaging piece is provided with a linear projecting end portion engageable with each of the groove portions.

Abstract: A flexible disk device, in which a handle member is manually operated to move a holding asembly which either holds a flexible disk in an operating position or releases the disk, for removal. A cam selectively couples a pair of magnetic heads simultaneously to engage the disk and to hold them in position. The cam also decouples the heads from the disk. The cam may comprise first and second cam sections, which are reversibly rotatable on both sides of the disk when it is held in an operating position, respectively. In this event, it is preferred to make a head withdrawing assembly to forcibly rotate the cam to withdraw the heads from the coupled state whenever the handle member is actuated to release the disk. The head withdrawing assembly may comprise a protrusion attached to the cam and an arm attached to the handle member which do not engage each other to leave the cam freely and reversibly rotatable when the disk is held in position.

Abstract: A magnetic recording/reproducing unit comprises a magnetic head for recording or reproducing information on or from a magnetic recording medium, a pushing member provided opposite the magnetic head via the magnetic recording medium for pushing the magnetic recording medium to the magnetic head, a housing for accommodating the magnetic head, and an elastic member arranged between the magnetic head and the housing for elastically supporting the magnetic head. Even if the pushing member collides with the magnetic head via the magnetic recording medium in the recording or reproducing mode, the shock of the collision is absorbed and a spacing loss between the magnetic head and the magnetic recording medium is suppressed.

Abstract: A magnetic head retaining device, comprising a support member carrying a magnetic head which contacts a magnetic recording medium such as a magnetic card moving in one direction relative thereto and at least a pair of support holes provided downstream and upstream to the magnetic head on an imaginary line passing through the magnetic head in parallel to the direction of the motion of the magnetic recording medium and a mounting member having at least a pair of legs inserted through the corresponding support holes and a spring portion for biasing the legs downwards. Each of the legs is provided with a step for restricting the upward motion of the supporting member. By forming the mounting member out of a single plate, the device may have the flexibility required for achieving an intimate contact between the magnetic head and the magnetic medium and the rigidity required for accurately positioning the magnetic head.

Abstract: A hub holder which pushes the center hub of a magnetic disc to a reference surface for setting is associated with a cassette guide for guiding a magnetic disc cassette to a recording/reproducing position at which information is recorded or reproduced to or from the magnetic disc, so that the hub holder's displacement can be amplified by a required degree. An upper dust-proof door and a lower dust-proof door are swingably disposed at the cassette insertion opening of a magnetic disc unit, and they are normally so biased that they close the cassette insertion opening dust-tightly. When they are closed, one of them abuts against the other. Thus, the magnetic disc unit is compact in size and light in weight, easily clamps the center hub of the magnetic disc, and is closed in a completely dust tight manner.