Abstract: A driver device for magnetic heads for a magnetic recording and reproduction apparatus. The driver device drives at least one combined head including at least two head members, each head member having a winding coil, and the effective gap width of the combined head is changed by selectively short-circuiting at least one of the winding coils. By switching a connection between the combined head and a record amplifier or a reproduction head amplifier, the effective gap width of the combined head is changed either to a narrow effective gap width for n time speed recording or reproducing or to a wide effective gap width for standard speed recording or reproducing.

Abstract: A circuit for compensating the errors occurring when changing the playing back speed of a double azimuth 4-head VTR includes first and second switches for switching data retrieved by four heads and amplified in response to head switching signals, a comparator for comparing the output signals of the switches, an alternate delay circuit for receiving the head comparing switching signals of the comparator and the head switching signals to delay horizontal synchronization by 2H during performing head switching between fields and not during not performing the head switching, a multiplexer for generating control signals in response to the output signals of the alternate delay circuit and head switching pulses, a third switch for transmitting data in response to the control signals of the multiplexer, a high frequency output unit of a pre-amplifier for receiving the outputs of the third switch, and a time base correction (TBC) circuit for receiving the video signals of the high frequency output unit of the pre-ampli

Abstract: A digital video/audio recording and reproducing apparatus comprising a video signal high-efficiency encoder having a variable reduction rate, an audio signal high-efficiency encoder having a variable reduction rate, and a controller for controlling the reduction rates in both of the high-efficiency encoders. The reduction rates in both of the high-efficiency encoders are controlled in such a manner that the sum of the information amount of the video signal and that of the audio signal, after high-efficiency encoding, is maintained constant. When recording multi-channel audio signals, the reduction rates in both of the high-efficiency encoders are controlled according to the number of audio signal channels to be recorded. The high frequency components of the high-efficiency encoded video and audio signals are recorded at the end portions of recording tracks on a magnetic tape, while the low frequency components thereof are recorded in the central portion of the recording tracks.

Abstract: A noise reduction apparatus wherein a sampled digital data is compared with a first threshold value (t) to average the digital data during a period while the level of low frequency components containing jitter noises is a predetermined threshold level or lower, an averaging operation for the digital data after a predetermined number of sampling points continues if a difference value between previously and presently obtained digital data takes a second threshold value (tp) or lower, the averaged digital data obtained during a predetermined number of rotations of a rotary head is converted into an analog signal, and the analog signal is subtracted from a reproduced signal.

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: In a digital signal magnetic recording/reproducing apparatus, input digital signals of plural channels and a recording current control signal expressing recording current values corresponding to the respective digital signals are time-division mulitplexed and transmitted into a rotary cylinder, and the digital signals and recording current control signal are separated by a circuit built in the rotary cylinder. The recording current for each of the digital signals is controlled depending on the recording current control signal. By time-division multiplexing the input digital signals of plural channels and transmitting the multiplexed signal into the rotary cylinder, the number of channels of the rotary transformer can be reduced. Further, by transmitting the recording current control signal into the rotary cylinder, the recording current of the digitally transmitted signal can be adjusted.

Abstract: A multifunctional control device and method is used to determine a head channel selecting signal for playback heads of a video tape recorder and for controlling a phase shift direction of a video signal according to a desired reproduction mode. The video tape recorder has four heads, a first pair for use during standard play and a second pair for use during super long play. The heads read out recorded video signals and a first switch is connected to the first pair of heads and a second switch is connected to the second pair of heads for selectively providing outputs to corresponding amplifiers, under control of a servo controller. A third switch is connected to the outputs of the amplifiers for providing outputs under control of a microcomputer. The microcomputer controls the servo controller which in turn controls the speed of a drum motor and a capstan motor. The microcomputer also provides a phase shift direction controlling signal.

Abstract: High density recording systems and methods are disclosed which employ a radiation beam to form spot-like recordings in record members such as discs, tapes and cards. The angle, offset or cross-sectional shape of the recording beam can be varied so as to vary the angle, offset or shape of the corresponding recordings in the record member. The recorded information can be electro-optically or magnetically detected and discriminated from each other to provide high density recordings of alphanumeric characters or digital data. Enhanced detection scanning is effected by ultrasonically vibrating the laser or an optical element, such as a prism or mirror receiving the reading light beam, in a manner to cause it to scan back and forth laterally to the record track as a longitudinal scanning movement is effected parallel to the longitudinal axis or centerline of the track. The reflected light is detected, computer processed and analyzed to effect proper detection of the recordings to generate correct data therefrom.

Abstract: In an arrangement for inductive transmission of a data signal to the recording head (9) in a magnetic tape recording device, in which the data signal to be transmitted to the recording head is delayed by a bit period, the undelayed signal and the delayed signal are combined and applied to an inductive transmission arrangement (11, 13). After passage through the inductive transmission arrangement, the combined signal is rectified in a rectifier (21) and then subjected to a DC voltage shift (22). The resultant signal is then amplified (10) and applied to the recording head.

Abstract: A digital audio tape recorder signal processor whose signal processing period is Td performs signal processing for recording 2-channel PCM signals having a sampling frequency of Fs. A circuit is provided for compressing the time-base of 4-channel PCM signals by one-half to form 2-channel time-base-compressed PCM signals in which the first and second channels are time-divided and multiplexed and the third and fourth channels are time-divided and multiplexed, so that when the time-base-compressed PCM signal is supplied to the signal processor, the signal processor is operated with a sampling frequency of 2Fs and the signal processing period is changed to 1/2 Td.

Abstract: A rotary head type magnetic recording and playback apparatus for performing an after recording only to a desired signal area by using a head (1,3) 2,4) having a core width broader than the track width (Tp) of a recorded tape (7), wherein recording heads (1,3) and playback heads (2,4) are provided at every channel (A,B), respectively, the respective heads are arranged at angular intervals of 90 degrees so that the playback heads precede the recording heads in the rotational direction (FC) of a rotary drum (8,9) in a plane of rotation thereof, and the respective heads are offset in the axial direction of the rotational axis of the rotary drum so that the lower edge (R) of each recording head traces the boundary portion between the tracks and the centers of the playback heads trace the central portion of the tracks.

Abstract: A phase-correction circuit comprises an amplifier, comparators, inverters, an S/R flip-flop, a switch and, a pulse width controller. The circuit sets a reference of recording position of a head to a tape and corrects the phase differences between the head, a magnet and a pulse generator, thereby realizing precise drum phase servo action and acquiring excellent audio and video recording and reproducing.

Abstract: A tracking control device comprises a tape driving device for driving a magnetic tap at a predetermined running speed; and a rotary head carrying a magnetic head, for rotating the magnetic head to trace a plurality of record tracks on a magnetic tape driven by the tape driving device, the magnetic head having two gaps which have different azimuth angles from each other, the respective gaps being adapted to be used to trace every other record track. A signal reproducing circuit is connected to the magnetic head, for reproducing as signal supplied from the magnetic head; and a pilot signal detector is connected to the signal reproducing circuit for detecting pilot signals included in the signal reproduced by the signal reproducing circuit, the pilot signals being recorded in record tracks on both sides of the record track which is traced by one of the gaps of the magnetic head, and for outputting pilot-signal detection signals each representing levels of the detected pilot signals.

Abstract: A high density helical scan recording device having write/wide-read heads and RAW/narrow-read heads of different widths to permit an increase in the density of data tracks and to allow backward compatibility for reading and recording conventional density data tracks. The write/wide-read heads are used to record data in tracks of either the conventional density or the high density. The write/wide-read heads are also selected to read conventional density data tracks. The RAW/narrow-read heads have a reduced width that permits reading of data tracks in which greater than two-thirds of each data track has been overlapped by an adjacent data track. The RAW/narrow-read heads are used in a read-after-write (RAW) capacity and are used during a read operation of the high-density data tracks.

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 digital signal reproducing apparatus for reproducing a digital signal from a recording medium on which a digital signal, including coded address data to identify a data block, is recorded includes a reproducing circuit for reproducing the recorded signal, a memory for storing the reproduced signal, an address extracting circuit for taking out the address data from the reproduced signal, a circuit for forming a reference address from the extracted address data, a comparator for comparing the extracted data and the reference address, and a writing circuit for selectively writing the reproduced signal into the memory in response to the output from the comparator.

Abstract: A magnetic tape cassette apparatus is disclosed which has a pair of electromagnetic data transducers mounted to a rotary drum to make up a rotary head assembly for data transfer with the magnetic tape. For electrically connecting each transducer to a recording amplifier circuit and a reproducing amplifier circuit, a transformer is employed which comprises a rotary winding mounted to the rotary drum, and two fixed windings electromagnetically coupled to the rotary winding. The two fixed windings are connected respectively to the recording amplifier circuit and the reproducing amplifier circuit. In another embodiment the transformer comprises one rotary winding and one center tapped fixed winding. The two sections of the fixed winding, electrically divided by the center tap, are connected respectively to the recording amplifier circuit and to the reproducing amplifier circuit.

Abstract: In a magnetic recording and reproducing apparatus, amplitude errors of recording currents respectively supplied to a plurality of rotary magnetic heads are detected, and, in individual periods of sequential scanning of a magnetic recording medium by the plural rotary magnetic heads, the gain of a variable gain amplifier disposed in a signal recording system sequentially supplying an input video signal to the plural rotary magnetic heads is controlled so as to automatically adjust the value of the recording current supplied to each of the rotary magnetic heads.

Abstract: In a recording and reproducing apparatus according to the present invention, a drum unit incorporates a first recording/reproducing control head. A second recording/reproducing control head is disposed within a running path of a magnetic tape. A control signal synchronizing with a record starting point of recording tracks is recorded by the first or second recording/reproducing control head. The second recording/reproducing control head is controlled in accordance with a state where the control signal is recorded or reproduced by the first recording/reproducing control head, thus recording or reproducing the control signal. A deviation in tracking which is caused due to stretching/contraction of the magnetic tape can be effectively avoided. The control signals can be recorded or reproduced more surely than in the prior art.

Abstract: A rotating scan device for use with magnetic storage media, including a rotor, multiple magnetic transducers on the rotor with suitable gaps and orientations for writing or reading electronically modulated signals directly to or from magnetic storage media. The transducers scan in a helical fashion and include video and audio heads. There are means on the rotor for receiving and amplifying the signals read by the magnetic transducers. The rotor has means on it for transferring the amplified read signals from the rotating device. The rotor also has means for receiving write signals, as well as means for driving the magnetic transducers with the write signals. Means are provided for transferring power to the amplifying, transferring, receiving and driving means. Analog switch means are located on the rotor for connecting one of the multiple video head signals to the transferring means, and the analog switch means has a control input.

Abstract: A magnetic recording/reproducing apparatus includes a plurality of heads attached on a rotary drum, a driver for driving the heads and a tape, head switching circuitry for producing one video signal by switching video signals picked up by the plurality of heads, video signal processing circuitry for processing the video signal produced by the head switching circuitry, and head switching point control circuitry for controlling the head switching circuitry so that the point of the head switching by the head switching circuit is included in the horizontal blanking period of the video signal. The head switching is performed within the horizontal blanking period of the video signal, and therefore no skew due to the head switching is generated in the reproduced video image.

Abstract: A rotary digital magnetic recording-reproducing apparatus includes an envelope detecting unit and a one-of-heads jamming detector. The envelope detector receives an RF signal, reproduced through two heads, having first envelopes indicative of a first head and a second envelope indicative of a second head. The envelope detecting unit produces from the RF signal a train of pulses indicative of the first and second envelopes. The one-of-heads jamming detector monitors the train of pulses to output a signal indicative of the trouble or jamming of one of the first and second heads when an envelope corresponding to one of the first and second heads is lost.

Abstract: A circuit used in a camcorder for monitoring the recorded state of a tape during recording by simultaneous playing back of the tape comprising first and second record/playback heads mounted on a head and drum assembly for performing a record and playback of the tape, a second amplifier for amplifying the signals of the first and second heads received via switches to produce chrominance record signals, third and fourth playback only heads mounted on the head and drum assembly between the first and second heads with a given interval for exclusively performing the simultaneous playing back, first and third amplifiers connected with the third and fourth heads via switches for amplifying the video signals picked up by the third and fourth heads, third and fourth switches for respectively connecting the signals of the third and fourth heads to the first and third amplifiers, or the output signals of the first and second heads selected by first and second switches to a second amplifier, and a head switching means fo

Abstract: A method of recording and/or playing back a data signal, in an apparatus in which a tape helically encircles a drum containing a headwheel, and the heads scan oblique tracks on the tape, features reduction of the tape velocity by a factor 1/n where n is a positive integer. Along with the tape velocity change, the static tracking angle between the tape and drum is correspondingly adjusted so that the heads will continue to scan along a standard track pattern or format. The data rate of data signals retrieved from the tape (e.g. high-date rate satellite transmissions) or of incoming data signals can be converted to a different data rate by intermediate steps of writing to a digital memory and reading back at a more desirable data rate.

Abstract: An apparatus for reproducing from a recording medium a frequency-modulated audio signal which has its carrier level in a specific period determined according to the kind of information and for producing the audio signal after processing the reproduced audio signal is arranged to control the signal processing action according to the output of a detecting circuit which detects the level of a difference between the carrier level of the frequency-modulated audio signal obtained in the specific period and the carrier level obtained in a period other than the specific period or detects changes taking place in the carrier level. This arrangement enables the apparatus to process the audio signal appositely to the kind of the frequency-modulated signal thereof without recourse to any additional reproducing circuit solely for this purpose. Further, the apparatus is arranged to prevent any faulty signal processing action by nullifying as necessary the output of the detecting circuit.

Abstract: A magnetic write/read device with use of a rotating drum system in which first and second writing heads are arranged around a rotating drum and the first and second writing heads overwrite first and second tracks on a magnetic tape so that one frame is formed by a pair of the adjacent first and second tracks, the magnetic write/read device comprises first and second reading heads arranged in the rotating drum and corresponding to the first and second writing heads, respectively and the controlling means for controlling each head in sequence so that the first track of the present frame is recorded by the first writing head and then the first and second tracks of the penultimate frame are reproduced by the first and second reading heads, and in turn the second track of the present frame is recorded by the second writing head.

Abstract: A digital magnetic recording/reproducing amplifying apparatus which includes a recording amplifying portion, a first reproducing amplifying portion, a switching portion, and a second reproducing amplifying portion. The apparatus has the advantage of uniform performance by a more simply defined recording current waveform with variable resistance and by performing a two-stage amplification while simultaneously reducing the number of amplifiers by half.

Abstract: The present invention is concerned with a magnetic recording apparatus, such as a video tape recorder, in which the recording circuit, provided with an amplifier connected to a magnetic head, is provided on the side of a rotary head drum. The record control signals for controlling the recording circuit are indicated by serial data and data enable signals indicating the data start and data end points of the serial data. The edge pulses of sync clocks of the serial data are gated by the data enable signals and connected to the serial data, and the transmission mode signals indicating the start and the end of the transmission are further annexed to serial transmission data to form serial control signals, which are then serially transmitted as record control signals from outside of the rotary head drum to the side of the rotary head drum from outside the rotary head drum for simplifying the transmission system for the record control signals.

Abstract: A digital video signal reproducing apparatus adapted for reproduction of a magnetic tape where video data of one field are recorded on a plurality of tracks by a plurality of rotary heads. Playback heads employed for such reproduction are mounted on bimorph bases or the like so that the vertical positions or heights of the playback heads are controllable and, if any of the playback heads is rendered faulty by some reason, the vertical positions thereof are controlled to select the order of the tracks from which the video data are to be reproduced, whereby required correction can be carried out with interfield concealment of the reproduced video data to consequently avert deterioration of the image quality.

Abstract: In an apparatus for digitally recording and reproducing video and audio signals in successive parallel slant record tracks on a record tape; pluralities of recording heads are mounted on a rotary drum at diametrically opposed positions so that one field of a video signal is recorded in a plurality of the tracks scanned by the recording heads as the record tape is advanced at a predetermined speed, a pair of bimorph leaves are mounted at respective opposed positions on the rotary drum, a plurality of reproducing heads are disposed on each of the bimorph leaves to be deflected by the respective bimorph leaf in a direction transverse to the direction along the record tracks when, in a reproducing mode, the tape is advanced at a speed different from the predetermined speed used for recording, and the number of the reproducing heads is greater than, for example, twice, the number of the recording heads for relatively reducing the maximum deflections of the reproducing heads by the bimorph leaves needed to achieve

Abstract: A rotary-head assembly for the storage and retrieval of digital data on and from a series of slanting record tracks on magnetic tape in cassette form or the like, with the capability of monitoring the recording being written on the tape. The rotary-head assembly includes a rotary drum to which there are mounted first and second magnetic read/write heads and first and second magnetic monitor heads. The two read/write heads alternately scan the magnetic tape for creating a series of slanting record tracks on the magnetic tape. For monitoring the data being written by the first and second read/write heads, the first and second monitor heads scan only parts of the widths of the record tracks created by the first and second read/write heads, respectively. The output signals of the monitor heads are therefore less in amplitude than if they scanned the full widths of the record tracks.

Abstract: An apparatus for selectively recording a baseband signal and a MUSE signal on a magnetic tape and for reproducing them at different speeds including: a magnetic head circuit having first and second groups of heads provided separately form each other. Each of the head groups includes four rotary heads for consecutively and helically scanning the tape to record and reproduce the baseband and MUSE signals.

Abstract: A coefficient setting circuit sets, in registers, coefficients corresponding to a position of each magnetic heads on a rotary drum. A counter circuit counts the number of pulses of a first reference clock signal employed as a reference signal for rotational control of the rotary drum. Comparison circuits compare the coefficients, set in registers, with a count value of the counter circuit and outputs reset pulses r1 and r2 when a match is detected between the set coefficients and the count value. In response to these reset pulses r1 and r2, counter circuits are reset to start the counting operation of a second reference clock signal. Consequently, decoders output timing pulses for controlling the timing of recording or reproducing operations for each magnetic head. The coefficients set by coefficient setting circuit are altered in accordance with alterations in the position of each magnetic head or the shape of the rotary drum, resulting in appropriate timing pulses.

Abstract: For reliable playback of digital video signals in slow-motion operation over a wide range of slow-motion speeds, auxiliary playback heads are positioned closely behind normal playback heads and offset by half a track width therefrom. Each of the playback heads have a circuit for regenerating clock and data signals which includes a PLL circuit and all of the PLL circuits have an output for the signal that shows whether the PLL circuit is locked in or not. The lock-in signals are supplied to first address inputs of an ROM which has a principal output showing whether the normal playback heads or the auxiliary playback heads have the larger number of locked-in PLL circuits and the group of playback heads having that larger number of locked-in PLL circuits is selected for having the data and clock signal outputs passed on to playback channels for further processing. The control of the switching circuit is improved by having auxiliary outputs of the ROM fed back to second address inputs thereof.

Abstract: A comparison circuit associated with a video tape recorder having two identical legs (41, 42), one of which (41) is connected to a head of a first type and the other (42) to a head of a second type, the outputs of both being connected to a respective input of a comparison means (56) for selecting in "search" mode the head which presents the highest signal amplitude. Each branch comprises, in series, a high-pass filter (45), a variable gain amplifier (46), a multiplier (47), a low-pass filter (48) and a capacitance amplifier (49).

Abstract: The read/write head buffer provides a buffer memory for each read/write head in the rotating media data storage system to that a seek request from the processor can be handled as soon as the beginning of the requested data record is positioned below the associated read/write head. The data image stored on the rotating media is read from the rotating media by the read/write head and stored in the read/write head buffer independent of the availability of a data communication path to the processor. Thus, the read data operation need not be synchronized with the availability of a data communication path to the processor and the requested data is retrieved from the rotating media as soon as the data record is properly positioned. In no case is the data retrieval time greater than one revolution of the rotating media. The error correction codes written on the rotating media to protect the integrity of the requested data are maintained since they are stored in the read/write head buffer along with the data record.

Abstract: A dual channel helical scan recording system (30) includes a rotating dum (36) having sets of heads (W1, W2) (R1, R2) mounted on its peripheral surface (56). A set of write heads (W1, W2) is situated on an opposite side of the drum (36) from a set of read heads (R1, R2). The write heads (W1, W2) simultaneously write two adjaent tracks (T1, T2), which are read for verification 180 detrees later by corresponding read heads (R1, R2). The heads (W1, W2, R1, R2) are strategically mounted on the drum (36) with respect to angular and axial placement, and have selected head widths and azimuthal angles. Should a block of data (317) written to tape (32) be determined, during readback, to be bad block, that bad block is subsequently rewritten on the tape (32) in the course of writing good blocks and amongst other good blocks. The rewritten block is recorded at a row position on the tape which is sufficiently displaced from the row position of a previous writing to avoid media defects occuring on the tape.

Abstract: Digital audio and video signals are recorded on successive tracks which extend obliquely formed on a video tape, and reproduced therefrom by reproducing heads which are movable in a direction transverse to the tracks by means of a bimorph device so that a plurality of tracks, corresponding to one field video and audio signals, are skipped in a variable tape speed mode. Tracks provided for the audio signal are arranged at opposite ends of the video tracks. In a mode where the head skips one field, the signal amplitude level of the audio signal reproduced from one end portion of the audio tracks is controlled so as to be gradually reduced and a signal amplitude level of the audio signal reproduced from the other end portion of a different field track portion is controlled so as to be gradually increased so that cross-fading thereof is effected.

Abstract: A video signal recording/reproducing apparatus with two groups of rotary heads which respectively include one main head and two auxiliary heads is set forth. The apparatus includes a head switching device for switching one of the two auxiliary heads into operation according to input video signals and a tape speed switching device for switching the running speed of a video tape according to the input video signals. The apparatus permits the video signal recording/reproducing of both video signals having a wide band and a narrow band. The apparatus also defines an effective tape wrap angle wherein the position of head switching is removed from a screen so that the division of images within the screen is avoidable and so that noise bars produced in the boarders of these images do not appear even in the case of special reproduction.

Abstract: In an over-write capable magnetooptical recording method and, more particularly, a bit position recording method, and a recording apparatus used therefor, a laser beam intensity is pulse-modulated between high and low levels according to data to be recorded. The modulated laser beam is radiated on a recording medium under the presence of a bias field. High-level emission time of the laser beam is shortened at the inner portion of the medium, and is prolonged at the outer portion. Low-level intensity of the laser beam is decreased at the inner portion of the medium, and is increased at the outer portion, thereby increasing C/N ratio upon reproduction.

Abstract: In a rotating head type reproducing apparatus of the kind reproducing an information signal using rotating heads from a record bearing medium on which a plurality of pilot signals of different frequencies are recorded in rotation along with the information signal, one in every recording track in a predetermined sequence, the levels of pilot signals reproduced from mutually adjacent tracks by a first rotating head are compared with each other; and the result of comparison is used in detecting the tracking error of a second rotating head which is reproducing the information signal.

Abstract: In an information signal recording apparatus having an m (m.gtoreq.2) number of heads arranged to record, in many parallel tracks on a recording medium, information signals of the m number of channels by simultaneously tracing the surface of the medium while simultaneously forming thereby the m number of tracks, pilot signals of an n number of kinds are recorded in rotation along with the information signals of the m number of channels in such a way as to recur in a cycle of an (n.times.m) number of tracks.

Abstract: In order to reduce the disturbances caused by the head switch in a videotape recorder, in an arrangement for demodulating an FM modulated signal, a fixed value in the hold circuit used for maintaining the fixed value for the signal during the head switch, is selected such that it is situated at a value the interpolated signal would have had during the head switch time interval (T.sub.1) at an instant situated between 0.3 T.sub.1 and 0.8 T.sub.1 in the head switch interval. This may be realized with a delay unit which realizes a delay T.sub.v for which holds: 0.3 T.sub.1 <T.sub.v <0.8 T.sub.1.

Abstract: Two magnetic heads having different azimuth angles are mounted spaced from each other on a cylindrical rotary drum. Data is recorded on a magnetic tape using of the magnetic heads. On the magnetic tape, one track is formed by one of the magnetic heads and another (second) track is formed by another magnetic head. The two tracks form one frame on the tape. The data is recorded in the unit of one frame. When reproducing, the data recorded in one track is read out by one magnetic head, and the data recorded in the other track is read out by the other magnetic head. When reproducing in the normal direction, the data in one frame is first read out on one track and then on the other track. When reproducing in the reverse direction, first the data of the other track is read out, and the data is fed into a delay circuit composed of memory. The delay circuit, after the data of one track is read out and output, outputs the data of the other track.

Abstract: A magnetic recording and reproducing apparatus including a recording head, reproducing heads and reproducing pre-amplifiers each mounted on a rotating cylinder for allowing recording and reproducing operations at the same time, in which two signal channels are defined by first and second double azimuth heads each made up of two reproducing heads and first and second integrated circuits are arranged on the rotating cylinder in close proximity to the first and second double azimuth heads, respectively. Each of the integrated circuits includes two pre-amplifiers corresponding to two reproducing heads of the first or second double azimuth head and selectively outputs one of two amplified reproduced signals from the above pre-amplifiers which is higher in signal level, and a head discrimination signal is added to the output signal.

Abstract: A rotational phase detecting apparatus for a head drum utilizing a video head capable of directly detecting the rotational phase of the head drum for the reproducing signal of the video head without using an additional pulse generating head by disposing a permanent magnet facing the rotational direction of video heads. When video heads pass by the permanent magnet, positive pulses are generated from the video heads and the positive pulse signal of the first video head is applied to a phase detecting signal processing unit via a rotary transformer and the positive pulse signal of the second video head is converted into a negative pulse signal at the rotary transformer and applied to a phase detecting signal processing unit.

Abstract: A reproducing apparatus which is provided with: frequency converting means for performing frequency conversion of the FM regenerative signals respectively from the read heads, on the basis of frequency conversion signals each having a frequency different from the frequency of the carrier; voltage-controlled oscillators for generating the frequency conversion signals, respectively; phase comparators for comparing phases of two FM regenerative signals frequency-converted by the frequency converting means in the overlap period so as to produce a difference signal corresponding to the difference between the phases; switching circuits for feeding the difference signal generated by the phase comparators, into one of the voltage-controlled oscillators generating the frequency conversion signal for frequency conversion of succeedingly reproduced one of the FM regenerative signals in the overlap period; and loop filters for stabilizing a loop system constituted by the aforementioned parts; whereby the phases of two fr

Abstract: Four heads are mounted with 90.degree. spacings between them to a rotary cylinder that rotates by 3/4 turn in each one field period of a video signal. Adjacent pairs of these heads having the 90.degree. spacing have different azimuth angles while opposing pairs of the heads having the 180.degree. spacing have mutually the same azimuth angle. A tape is wound helically in about 3/4 turn on the rotary cylinder and travelled thereon, so that the frequency of a pilot signal for tracking control to be recorded on each track with a video signal by each head is different between the tracks and the same frequency as the frequency of the pilot signal reproduced from the reproduction track in the reproducing mode is used as a reference pilot signal for tracking in the reproducing mode.

Abstract: In a magnetic recording and/or reproducing apparatus of a rotary head type, a magnetic head having two gaps of different azimuth angles is installed on the rotary drum and a switching signal, the polarity of which is inverted every rotation of the rotary drum is generated. The duty of the switching signal is adjusted so as to correspond to a time-difference between the two gaps of the above head. The timings of the recording operation and the reproducing operation to be performed by the magnetic head are controlled on the basis of the above adjusted switching signal.

Abstract: A digital signal recording and playback apparatus having a rotary heads mounted on a rotary drum capable of recording/reproducing a digital signal onto/from a magnetic tape at a tape speed which is N times as much as the standard speed while conforming to the standard track angle and length. The number of the rotary heads are increased from the standard two heads whereas the drum speed is made one half of N times standard speed and the drum diameter is made slightly larger from the standard so that the relative speed between the running tape and the rotating heads becomes equal to the standard in the double tape speed mode, and becomes twice that in the quadruple tape speed mode.