Abstract: A tracking system for positioning a light spot onto a magneto-optic disc having a beam guide track preformatted thereon, includes a main light beam and two auxiliary light beams, and a circuit for switching between a low frequency component of a tracking error signal, detected by respective auxiliary light beam detectors, and a tracking error signal detected by a main light beam detector.

Abstract: In a waveform equalizer of the present invention, first and second Hilbert-transform signals are formed from a parallel-reproduced signal, and a desired signal is obtained from these signals by an operational amplifier. The waveform equalizer includes a reflecting section having a plurality of resistors, and a switching section for selecting one of the resistors in accordance with a control signal. Therefore, the waveform equalizer can process a plurality of reproduced signals which have different ratios of the longitudinal signal component to the perpendicular signal component without being affected by inphase noise.

Abstract: An optical storage system has an information containing film of a material which has a crystallization temperature between 100.degree. C. and 400.degree. C. and can be switched between the amorphous and the crystalline states. Both the amorphous and crystalline states are substantially a single phase where the stoichiometric ratio of the material remains unchanged. Spots on the film is heated with a circular laser beam with a controlled pulse duration and intensity to melt the material in the spots. The spots are quenched at one rate to produce the amorphous state, and in a second revolution of the disk, at a different rate to produce the crystalline state.

Abstract: The invention relates to a tape transport mechanism in which two reels are respectively driven by different motors, thereby transporting a magnetic tape from one reel to another reel by passing through the portion of a read/write head without any variation in tension. At the initial stage to transport the magnetic tape, an acceleration time from a stop state of the tape until a tape speed reaches a reference speed and an average tension deviation to be applied to the magnetic tape during this time are obtained. Correction values to correct variations in run characteristics of two reel drive systems are calculated by use of the acceleration time and the average tension deviation. Upon next and the subsequent magnetic tape transport, currents to be supplied to the motors to drive two reels are controlled by use of the drive current command values corrected by those correction values.

Abstract: In a data playback system in which multiple disks are stored in a magazine, a first random number is generated to select one of the disks believed to be present in the magazine, or temporarily, on the turntable. A disk fetch is attempted and it is determined from the success of the fetch whether or not the disk is present. If not, a memory is updated to eliminate such disk from a catalog and disk selection is repeated. Then a table of contents is read, either from the disk or from a previously written random access memory. A second random number selects a block of data on the selected disk for playback. If the table of contents is stored in random access memory, it is completed as the information becomes available. Then the process is repeated for other randomly selected disks and data blocks.

Abstract: An amplifier for voltage biasing and amplifying the signals produced by a magnetic sensor is provided. Electrically, the resistance of the sensor is disposed between the bases of a differential pair comprising the input stage of the amplifier. Constant bias voltage for the sensor is provided independently of sensor resistance. DC feedback to the input stage balances current flow in both paths of the differential input stage to correct for DC offset arising in the output from input stage emitter resistor. The amplified signal, representing .DELTA.R.sub.h /R.sub.h, is sensed as a voltage across the magnetoresistive sensor, where .DELTA.R.sub.h is the change in steady-state resistance, R.sub.h, of the sensor.

Abstract: In an information signal recording and reproducing apparatus arranged to record in rotation pilot signals of a plurality of kinds having different frequencies, one in each of recording tracks along with an information signal on a recording medium and to reproduce the information signal from the recording medium, the relative positions of a rotary head which is reproducing the information signal and the recording medium are controlled by using the pilot signals reproduced by the rotary head and reference signals of a plurality of kinds which are of different frequencies corresponding respectively to the pilot signals of the plurality of kinds and are generated in rotation; and the generating sequence of these reference signals is changed by skipping a given number of reference signals according to signals reproduced by a rotary erase head during a reproducing operation.

Abstract: An optical recording/reproducing apparatus includes a pickup with a laser light source, an objective lens and lens drive coil for moving the optical axis of the laser beam transmitted through objective lens, a carriage drive voice-coil motor for moving a carriage with the pickup mounted thereon to move the laser beam transmitted through the objective lens, and tracking apparatus for operating both the lens drive coil and the carriage drive voice-coil motor. The tracking apparatus includes a lens servo stable detecting device for detecting that the laser beam from the objective lens has reached a desired track, apparatus for turning on a servo control loop with the lens drive coil in response to a tracking instruction, and apparatus for turning on a servo control loop with the carriage drive voice-coil motor in response to a detection output from the lens servo stable detecting device.

Abstract: A reproducing apparatus for magneto-optical discs has a moving head portion and a fixed head portion. Light reflected from the disc is divided into two parallel light beam components having different planes of polarization. These light beam components are transmitted to corresponding light intensity detectors of the fixed head portion. The outputs of the detectors are unaffected by movement of the movable head portion relative to the fixed head portion radially of the disc and are unaffected by movement of the movable head portion in other directions due to inaccuracies in the slider mechanism that moves the movable head portion radially.

Abstract: The information recorded in the data carrier in the form of a locally variable electric polarization is scanned and selected by means of an electron beam. For this purpose, the secondary electrons produced on the surface of the data carrier are used. The data carrier is simultaneously either periodically heated by radiating electromagnetic waves or charged with ultrasonics. Potential fluctuations of equal frequency thereby arise on the surface of the data carrier dependent on local polarization, which fluctuations result in a modulation of the secondary electrons. The secondary electron flow thus receives information via the polarization conditions stored in the data carrier. To recover this information, the secondary electron flow is frequency-selectively amplified and electronically evaluated according to amount and/or phase. A polyvinylidene flouride film (PVDF) is preferably used as data carrier.

Abstract: A telephone answering device with an amplication feature during outgoing message has a blank portion for a couple of seconds between first outgoing message and second outgoing message. If a calling party speaks his name during the blank portion, his voice is amplified in the region of the device to be answered by any people around it. If the calling party does not speak his name, however, a second outgoing message will be produced after the blank portion. After a beep tone, the calling party can leave his message on the incoming message tape.

Abstract: A disk data storage subsystem includes a head and disk assembly. A plurality of sectors in data tracks include a servo portion containing a prerecorded pattern of a plurality of repeating, time staggered, non-phase-coherent bursts, each burst having a predetermined integral fraction radial offset relative to the other bursts.

Abstract: A data transfer apparatus for use with a replaceable disklike record medium such as a flexible magnetic disk having data storage tracks thereon, comprising a disk drive motor for imparting rotation to the record medium, and a head transport motor for transporting a transducer head or heads radially of the record medium so as to enable the transducer head or heads to access the individual data storage tracks on the record medium for data transfer therewith. Also included is a control and drive circuit for controllably energizing the head transport motor. When the record medium is not loaded in the apparatus, the control and drive circuit holds the supply voltage of the head transport motor zero, or lwoer than its normal operating voltage for head transportation, for saving power.

Abstract: A tracking control system is capable of simplification of tracking operations for a recording and/or reproduction apparatus, such as VTR. The tracking control system employs an up-switch and a down-switch for increasing and decreasing tracking control or adjustment magnitude. This simplifies tracking operations to be performed by the user. The tracking control system additionally facilites with the feature of instantly setting the tracking control system at a predetermined position. Instant setting operation is performed by operating the up-switch and down-switch simultaneously.

Abstract: A magneto-optical recording disk has a transparent resinous substrate with a pre-groove, and a metallic recording layer formed above the substrate. A transparent adhesive layer is provided between the substrate and the recording layer, for allowing a laser beam to pass therethrough, and for causing the recording layer to be tightly adhered to the substrate to thereby prevent the recording layer from being peeled off from the substrate. The adhesive layer is comprised of a fluorine resin material.

Abstract: A control system for positioning a head in a magnetic disk device. The control system including a stepping motor, an index timing sensor for indicating the starting point of a data track, a rectifier for rectifying the servo position information, and a envelope detector for detecting the envelope of the rectified servo information. The servo position information is recorded in at least two data tracks and is formed in a staggered, offset pattern. The outside and inside tracks can serve as reference tracks for use in predicting the expected position of an intermediate track between the reference tracks by the use of linear interpolation.

Abstract: A data transfer apparatus for use with a replaceable disklike record medium such as a flexible magnetic disk having data storage tracks thereon, comprising a disk drive motor for imparting rotation to the record medium, and a head transport motor for transporting a transducer head or heads radially of the record medium so as to enable the transducer head or heads to access the individual data storage tracks on the record medium for data transfer therewith. Also included is a control and drive circuit for controllably energizing the head transport motor. When the disk drive motor is out of rotation, the control and drive circuit holds the supply voltage of the head transport motor zero, or lower than its normal operating voltage for head transportation, for saving power.

Abstract: An apparatus for storing and releasing information contains at least one reading device for reading codings arranged upon, or associated with, saleable goods. Also provided is a storage unit for storing information and a corresponding output unit. The apparatus offers to users, in department stores or the like and directly and reliably, specific information concerning products to be sold. The data processing unit comprises a programmable coding unit by means of which, on the one hand, address signals for the information and, on the other hand, associated codings are stored. By use of a reading device, and through the coding unit, the desired information is called upon from the storage unit and is made accessible on the output unit.

Abstract: A digital signal reproducing apparatus in which the frequency of a basic clock signal generated from a clock generator having a fixed oscillation frequency is divided to produce a clock signal used for processing a digital signal, and, when the transmission speed of the digital signal is changed, the frequency division ratio is also changed to produce a clock signal synchronous with the digital signal transmitted at the changed transmission speed.

Abstract: In an optical information reproducing apparatus for reproducing an information recorded on a recording surface of a disc-shaped record medium and which includes an optical pick up device mounted on a tiltable optical block and having a laser beam source for generating a laser beam and a photo detector for detecting the reflected beam from the recording surface and for reading the recorded information, a skew error detector mounted on the tiltable optical block for detecting skewing of the record medium and a skew error corrector controlled by the output of the skew error detector for controlling the optical block so that an optical axis of the pick up device is maintained perpendicular to the recording surface; the skew error detector includes diffused light source, a divided photo detector and a lens, the light source and the divided photo detector being arranged symmetrically with respect to an axis parallel with the optical axis of the optical pick up device, the light irradiated from the diffused light so