Abstract: An apparatus having a magnetic head assembly including a plurality of arms each arm having a magnetic head fixed to a nose portion thereof and a magnetic disk unit having a plurality of magnetic disks mounted on a rotating shaft. The spacing between adjacent magnetic disks being set at a value corresponding to the thicknesses of the magnetic heads fixed to two of the arms, plus the thickness of the two arms, plus a rotating gap of the magnetic heads, plus a space of 0.1 mm or less. Further included is a disk height measuring device and a head measuring device for measuring the heights of the disks and the magnetic heads. An expansion device expands the spacing between the adjacent arms. The spacing between the adjacent arms being expanded an appropriate amount to provide optimal operation of the magnetic disk apparatus.

Abstract: An FM signal which is partly missing zero crossing points is supplied to an input terminal, to which a second polarity discriminating circuit and a lower side band suppressing circuit followed by a first polarity discriminating circuit are coupled together. A pulse extracting circuit receives the outputs of the first polarity discriminating circuit and a second polarity discriminating circuit to produce pulses corresponding only to portions of the FM signal at which the zero crossing points are absent. The pulses thus obtained are subsequently combined in a waveform reforming circuits with the FM signal from the input terminal, thereby permitting the FM signal to regain the zero crossing points.

Abstract: In a magnetic disk apparatus according to the present invention, a slider has a sliding surface and a reflecting surface. The height of the reflecting surface from the magnetic disk is greater than that of the sliding surface from the disk, when the slider flies above the disk, so that there exists a minute difference in level between the sliding surface and the reflecting surface. The flying height of the sliding surface of the slider from the magnetic disk is measured. When the magnetic disk is rotated, the slider flies from the disk. In this state, a reference flying height, i.e., the flying height of the reflecting surface from the magnetic disk is measured by the optical interference process. Then, the minute difference is substracted from the measured reference flying height to obtain the flying height of the sliding surface of the slider from the magnetic disk. According to the invention, even if the minimum flying height of the sliding surface of the slider is shorter than 0.

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: A magnetic disc cartridge has a lifter supported by a wall of the disc cartridge. The lifter has a riser for pressing a liner or liners against a disc sheet rotatably supported in the disc cartridge. The pressing force B/A of the riser is at least 0.6, where A equals the pressing force of the riser which is measured at ordinary temperature and humidity during an initial period when the lifter is combined with the cartridge, and B is the pressing force of the riser which is measured at ordinary temperature and humidity after the cartridge has been held at a temperature of 60.degree. C. and a humidity of 80% for seventy-two hours.

Abstract: A cassette changer for automatically inserting and discharging (changing) tape cassettes for a magnetic recording-reproduction apparatus of the front loading type, such as a video tape recorder. The cassette changer has a cassette discharge path for discharging a cassette along a slope when the cassette is ejected from the cassette inlet-outlet opening of the apparatus after recording or reproduction, a cassette insertion path intersecting the discharge path in front of the opening for guiding a new cassette along a horizontal plane into the opening for recording or reproduction, and a separator disposed at the intersection for alternately opening the paths for the discharge and insertion of the cassette.

Abstract: A magnetoresistance type magnetic head, in which a magnetoresistance film is disposed through an insulating film between two soft magnetic bodies, and a signal leadout conductor for the magnetoresistance film is disposed in the insulating film so that its surface is at the same level as that of the insulating film, thereby providing a high-performance magnetoresistance type magnetic head, in which the gap length is small and the resistance of the signal leadout conductor portion is small.

Abstract: A coupling device for the transmission of an axial movement from a lift generator to a rotatable, axially movable body, composed of: a component creating a pressure-transmitting contact between the lift generator and the body; and a device including a magnet producing a magnetic field which creates a magnetic attraction force between the lift generator and the body.

Abstract: A magnetic tape cassette having two symmetrical sides and which includes a cassette body having shaft-receiving holes formed respectively in right and left walls of the cassette body in such a manner that the holes are elongated in the front-to-rear direction of the cassette body. A substantially U-shaped guard panel is provided having rotary shafts on both ends engaged with the elongated holes so that the guard panel can be swung about the rotary shafts. A spring is connected between the cassette body and the guard panel to urge the latter to close the opening formed in the front wall of the cassette body.

Abstract: A memory apparatus suitable for storing data for a high resolution bit mapped display includes large capacity (e.g. 64-k) semiconductor random access memory circuits in which to reduce the effective access time the circuits are operated and addressed in a repeating cycle including in succession reading from two or more addresses in sequence having the same row address component (i.e. in page mode), for example for the display, and writing into or reading from a randomly selected address.

Abstract: A tape recorder comprises transfer mechanism which is operatively connected to a power switch and transfers a head support lever to a position where a magnetic head is in contact with a tape upon shifting of the power switch to its "ON" position. The power switch has "ON", "OFF", and "EJECT" positions in order, and, when set in the "EJECT" position, rocks a rockable eject lever for cassette ejection.

Abstract: An improved "floppy cartridge" is described comprising a jacket especially adapted for containing a pack of flexible disks, this jacket accommodating convenient insertion and withdrawal of the disk pack, while also permitting rotation and associated partitioning of the pack, as well as head-insertion and transducing on a selected disk--all with the pack kept contained within the jacket.

Abstract: A control apparatus for controlling a microcassette tape transport of one motor type includes a first designation means (106) for designating a constant speed transport mode, a rewind mode, and a fast forward mode; a second designation means (124) for designation a direction of the motor rotation; a third designating means (122) for designating a direction of the tape transport. In order to effect the control of a tape transport on the basis of the combination of designations by the first, second and third designation means, the apparatus further includes a first memory means (301) which operates, e.g.

Abstract: An improved charged coupled device time base corrector system to compensate for a change in the phase or frequency of input video signals, as occurs in the playback of a video tape recorder, by changing the nominal delay through the corrector, comprising, in combination, an input feedback circuit and an output feedback circuit. The input feedback circuit includes two cascaded infinite gain circuits, an infinite gain phase detector followed by an infinite gain voltage amplifier which gives an error voltage that controls the frequency of the voltage controlled oscillator (VCO) utilized to control the system delay. The output servo loop always adapts itself to the input error voltage. The VCO is thereby driven at a rate of change of its frequency proportional to the incoming error signal. .

Abstract: The present invention relates to a rotary head assembly for a magnetic recording and reproducing device such as VTR. A stationary center shaft is mounted on the side of a stationary cylinder while a rotary sleeve which is fitted over said stationary center shaft for rotation about the axis thereof is disposed on the side of a rotary cylinder. A lubricating oil is injected between the rotary sleeve and the stationary center shaft so that a space between the cylinders may be utilized so as to provide a hydraulic bearing portion. Thus, the rotary head assembly may be made compact in size and to a higher degree of accuracy. In addition, the thrust load carrying point of the hydraulic bearing portion is located on the side of the rotary cylinder, and the portion adjacent to the thrust load carrying point has a sealing arrangement or construction so as to prevent the leakage of lubricating oil and to stabilize the rotation of the rotary cylinder.

Abstract: In accordance with the present invention there is provided an electrographic recording apparatus for recording on an electrostatic charge retentive record medium and a driver circuit suitable for use therein. The apparatus comprises a plurality of recording electrodes mounted in close proximity to the record medium. A plurality of complementary electrodes are mounted in electrical cooperative relationship with the recording electrodes. Improved driver circuits are provided for applying a voltage to the electrodes. The driver comprises a current branch to which the electrode is connected. A current control is provided for supplying a current through the current branch, which current biases diodes to force the electrode to a reference potential. The current further charges an electrical storage element. To apply a high voltage to an electrode, the current control blocks the current flow. The potential stored in the storage element which causes a base-emitter current flow to forward bias the transistor.

Abstract: Apparatus for receiving a transmission including message signals each preceded by a recording device selection component and recording each message signal on a recording device identified by the selection component. The apparatus includes a plurality of recording devices, means for identifying the recording device selected by the selection component and for actuating the recording device to record the next succeeding message signal.

Abstract: An enclosed-type magnetic disc recording and/or reproducing apparatus according to this invention, having a pressure chamber to enclose a bearing unit of a flange rotating along with a magnetic disc, introduces an air pressure at a high-pressure portion, created by an air flow produced by rotation of the magnetic disc and the flange, into the pressure chamber so as to raise the pressure within the pressure chamber to a level higher than 1 atm., thereby preventing the lubricant evaporated from the bearing member from sticking to the magnetic disc or head to lower the faculty thereof.

Abstract: An improved automatic reverse apparatus for a magnetic tape recorder/player of the type which employs a magnetic tape contained in a cassette provided with first and second channels. The apparatus further includes a magnetic head with head channels adapted to contact and selectively record or reproduce each of the tape channels. A pair of reels are provided for winding and rewinding the tape and a pair of capstans and pinch rollers are utilized for alternatively transferring the tape in the forward and reverse directions between the reels. The apparatus includes an operating lever which can be moved and set at two different positions to effect reversal of tape direction and switching between tape channels. A mechanical signal is generated when the tape has been fully wound upon one of the reels which in turn causes reciprocating movement of an actuator mechanism. The latter movement causes the operating lever to swing to either its first or second position.

Abstract: A disc recorder includes a rotating recording disc and a transducer carriage which is transversely movable with respect to the axis of rotation of the rotating disc. The transducer carriage includes a mounting surface which is substantially perpendicular to the rotating disc and substantially parallel to the direction of movement of the carriage. A transducer holding plate is positioned adjacent and parallel to the mounting surface and a parallel motion linkage attaches the holding plate to the carriage. The linkage confines the motion of the transducer holding plate in a plane parallel to the mounting surface to motion which is substantially perpendicular to the rotating disc. A spring is provided biasing the holding plate against the mounting surface and biasing the holding plate toward the rotating disc. The transducer is positioned on the holding plate such that it coacts with the rotating disc. Friction reducing pads may be positioned between the mounting surface and the transducer holding plate.