Abstract: A rotary head magnetic tape apparatus, in which a take-up reel is driven in a controlled manner so that the detected tape running speed is equal to a reference tape running speed corresponding to preset tape speed data, and the rotary drum is driven in a controlled manner so that the detected drum rotating speed is equal to a reference drum rotating speed associated with the preset tape speed data, such that the speed of a track the magnetic tape relative to the magnetic head provided on the rotary drum may be accurately maintained.
Abstract: Apparatus is provided for switching between recording and playback modes of a tape recorder having a single input/output jack to which an output plug for an earphone, a headphone or the like, or an input plug for a microphone or the like can be connected. The jack is compatible with two channels. When a remote-control unit having a remote-control switch and connected to an input/output transducer is connected to the jack, one channel is used as an input channel for a remote-control signal, and the other channel is used as an input/output channel for an audio signal. In another embodiment, the tape recorder has a control circuit for discriminating between insertion of a 1-channel plug and insertion of a 2-channel plug into the 2-channel jack to control the operation of switches included in this tape recorder.
Abstract: A mechanical variation of a voice coil motor and an electrical variation of a servo loop are corrected, thereby performing a head positioning control of a high accuracy. When a measurement mode is set, a zero-cross frequency f.sub.0 at which a gain of open loop characteristics of the servo loop is set to 0 dB (gain =1) is known. By adding the frequency f.sub.0 to the servo loop, an open loop gain G.sub.OP is obtained. A correction coefficient K to set the open loop gain into an ideal value 0 dB (gain=1) is obtained as K=1/G.sub.OP and is stored into a correction table. In the ordinary access, a drive signal of an actuator is corrected by a correction coefficient K read out with reference to the correction table in accordance with the present cylinder position and the corrected drive signal is sent to the actuator.
Abstract: A VTR has heads adapted for reading out a video signal, a PCM audio signal, and an FM audio signal, respectively, from a magnetic tape, and a signal detecting circuit operable to detect which of the video, PCM and FM signals are recorded on the magnetic tape and to provide a signal indicative thereof to a system control circuit which controls a switching circuit for selectively connecting FM and PCM audio demodulating circuits with a signal output line, so that the video signal and the PCM audio signal or the video signal and the FM audio signal are output to be reproduced. The VTR further includes a recording system adapted to record a video signal, a PCM audio signal, and an FM audio signal in respective magnetic layers of a magnetic tape which are at different depths relative to the surface of the magnetic tape in accordance with a predetermined recording current relationship used for recording the video, FM audio and PCM audio signals so as to improve the S/N ratio of each signal when reproduced.
Abstract: A disk drive in which the radial alignment, track zero alignment, index to data timing, write current, asymmetry and threshold dropout can be electronically adjusted. A plurality of programs stored in random access memory run a plurality of adjustment procedures used to control the electronic adjustment functions of the disk drive. An alignment disk read by the disk drive provides alignment data for the radial, track zero and index to data alignment procedures. A microstepper circuit in the disk drive allows the read/write heads to be moved in discrete steps of approximately 1/126 of the track pitch for electronically adjusting the radial and track zero parameters. The index to data alignment is set by generating and storing an artifical index offset value. The write current and asymmetry adjustment procedures utilize digital to analog convertors (DACS) to vary the voltage supplied to the read/write heads. The threshold dropout procedure utilizes a DAC to control the output of a pulse detector.
July 13, 1990
Date of Patent:
July 26, 1994
Gregory M. Galloway
Gregory M. Galloway, Titus E. Davis, Roger O. Williams
Abstract: A video signal recording/reproducing apparatus is provided a rotary drum, recording and reproducing heads. Synchronous separation units separate vertical synchronous signals from input and reproduced signals. A memory stores a time difference which represents an elapsed time between when the recording and reproducing heads pass a given location. The time difference stored in the memory is used to control the rotation of the rotary drum.
Abstract: A process is provided for compensating for offset in the actuator current of the servo system of a disc drive. A typical disc drive includes a power amplifier providing actuator current to the actuator coil of the drive. A sensing resistor is responsive to the actuator current to provide a feedback signal representative of the magnitude of the actuator current, the feedback signal being provided to the power mechanism to derive the actual actuator current. By the present technique, offset in the actuator current is compensated by operating the transducer to move at predetermined constant velocities (for example, the maximum velocities) in first and second opposite directions across the surface of the disc and by measuring the resulting actual velocities. The feedback signal is adjusted based upon any difference between the actual velocities measured in the first and second directions.
Abstract: A series of longitudinal tape movement and lateral tape head movement operations are performed to collect data by which the physical format or cartridge type and also the magnetic format are simultaneously determined. The tape format detection system works during the load point seeking sequence and it is therefore able to determine the tape format type while the tape head is being positioned for use. Both longitudinally spaced and laterally spaced format identification fingerprints can be detected and analyzed.
Abstract: A cassette autochanger for automatically supplying and selectively reproducing a plurality of cassettes (C) having programs recorded therein comprises a plurality of recording/reproducing devices (3), a plurality of cassette storage locations (5, 6), a cassette transporter (4, 9) for transporting the cassettes (C) between the locations (5, 6) and the devices (3), a first detector (23) for detecting any one of the programs that is recorded in one only of the cassettes (C) , a second detector (23) for detecting two of the devices (3) which are available for use, and a dubbing controller (24) for controlling the two detected devices (3) so that such one of the programs is automatically dubbed on to another cassette (C) using the two detected devices (3).
Abstract: A video signal is recorded in successive tracks on a recording medium together with a pilot signal, the latter having a frequency that changes cyclically with a different one of at least four frequencies in successive tracks. A field detector detects sequential fields in the frames of the video signal, and rotation of the usual rotary transducers is servo-controlled in response to the detected sequence of fields and a pulse that is generated as the transducers rotate to represent the rotational phase of those transducers. A pilot signal generator generates the pilot signal with an initial frequency determined by an initial field in the detected field sequence, and with this frequency changing as a function of the detected sequential fields.
Abstract: A recording head arrangement is disclosed which may be employed in a video signal recording and/or reproducing device in which a video tape is helically wound on a drum carrying recording heads for recording and/or reproducing a video signal. The video signal is divided for representing upper and lower half images on a screen. The recording head arrangement includes first and second heads mounted on the drum adjacent each other. The first and second heads have the same azimuth angle which is inclined in a first direction with respect to a direction perpendicular to the head advancing direction. Third and fourth heads are mounted on the drum 180 degrees spaced from the first and second heads, respectively. The third and fourth heads have the same azimuth angle which is inclined in a second direction, opposite to the first direction.
Abstract: An automatic tracking method for detecting an optimized, accurate tracking level in a video tape recorder system to automatically sustain picture quality monitors a variation of the tracking level to continually detect a highest tracking level. Tracking data corresponding to the highest tracking level is set as output tracking data, to continually sustain optimized tracking.
Abstract: The lubricant film for a near contact magnetic recording device is maintained by a closed loop servo control for a recirculating lubricant supply system. A reservoir closely overlies the disk data surface and includes a heater for controlling the temperature difference between the reservoir and the disk surface. Decreasing the heater current reduces the film thickness and increasing the heater current increases the film thickness. A wick system gathers lubricant from within the disk enclosure, which may have been spun off the disk or condensed from the lubricant laden atmosphere and returns the lubricant by capillary action to the reservoir. Further, the reservoir includes two portions which are independently controllable. The first overlies the data band of the disk and the second overlies the start/stop zone and the head when the latter is not operational and parked at the nonoperating location.
December 30, 1992
Date of Patent:
May 3, 1994
International Business Machines Corporation
Thomas A. Gregory, James A. Hagan, Christopher G. Keller
Abstract: In a multi-disk system, index equivalent signals from a plurality of disk units are identified, and an average phase value of each disk unit is calculated from the identified signals so that each disk unit can synchronize its rotation phase according to the result of calculation and the index signal thereof in order to eliminate the need for a master index for the synchronization of rotation speed and rotation phase.
Abstract: An apparatus in which an information signal recorded on a tape-like recording medium formed with a number of tracks in accordance with a first or second recording mode in which the number of recording tracks per unit time differ, is reproduced from the tape-like recording medium by reproducing assembly including first and second reproducing heads.
Abstract: A rotary head type recording apparatus having a rotary head which is arranged to record signals on a tape-shaped recording medium by tracing the medium; a transport device for longitudinally moving the tape-shaped recording medium; a recording circuit which is arranged to cause a recording signal to be recorded on the recording medium by supplying the recording signal to the rotary head; a recording control circuit which controls the start and stop of signal recording by the recording circuit; and a transport control circuit which controls the start and stop of the recording medium moving action of the transport device. The operation timing of the recording control circuit is arranged to be substantially identical to that of the transport control circuit.
Abstract: A tape player includes a changeover mechanism for shifting the position of a tape travel direction changeover member in response to the reciprocating movement of a rewind pushbutton actuator, a head channel selector switch connected to the changeover mechanism via a resilient connecting mechanism and shiftable in response to the shifting operation of the changeover mechanism, silence detecting for detecting a blank interval between recordings on a magnetic tape and producing a silence interval detection signal upon detection of the blank interval, a latch mechanism for releasably holding the rewind pushbutton actuator in its advanced position, the latch mechanism being responsive to the silence interval detection signal for releasing the rewind pushbutton actuator, and blocking member for blocking the shifting operation of the head channel selector switch during the forward movement of the rewind pushbutton actuator.
Abstract: A zoom lens camera records an image to be photographed. A zoom switch is operated to drive a zoom lens of the camera. The zoom lens is driven in response to the operation of the zoom switch, and is controlled so that the zoom lens and the image recorder are alternately activated when the operation of the zoom lens and the operation of the image recorder are simultaneously instructed.
Abstract: A magnetic recording and reproduction apparatus includes a rotary drum to be driven to rotate, a first head provided on the rotary drum, a second head provided on the rotary drum so as to be set in an enable state when the first head is in a disable state, first and second amplifying circuits connected to the first and second heads, respectively, and capable of being set in an enable or disable state by a selection signal, a rotary transformer commonly coupled to the first and second amplifying circuits, and a selection signal generating portion for supplying a selection signal to the first and second amplifying circuits in synchronism with rotation of the rotary drum.
Abstract: A video recording and playback device with a built-in video camera includes an outer case having the same profile as that of a tape cassette that can be inserted into an exiting stationary video tape recorder.
December 19, 1989
Date of Patent:
December 28, 1993
Matsushita Electric Industrial Co., Ltd.