Abstract: In a system for recording and reproducing digital signals on a magnetic tape using a rotary head, in which the signals are recorded as a series of slanted tracks without guard bands, pilot signals that control tracking alignment of a playback head are recorded at particular positions in a specific pilot signal record region, independent of the information signal record region. Position detecting signals having various recording lengths are also recorded in the pilot signal region in such a manner that the start position of each position detecting signal corresponds substantially to the center portion of the pilot signal on an adjacent track.

Abstract: In an apparatus for reproducing signals recorded in a plurality of slant tracks on a recording medium by a rotary head, the signals in the tracks contain a digital information signal in a first predetermined area on the slant tracks and a tracking control signal including a tracking pilot signal and an erase signal in a second predetermined area. When the recorded tracks are reproduced by a rotary playback head having a tracing width greater than the track width, the pilot signals from the adjacent tracks will be detected and compared in level. A tracking signal for controlling the tracking alignment of the rotary playback head is generated in response to the level comparison. The level of the tracking signal is adjusted in response to the level of the tracking control signal.

Abstract: A method of recording a digital audio signal in association with a digital video signal which is to be recorded in oblique tracks on a magnetic tape using a rotary head the rotational frequency of which is locked to the digital video signal, comprises the steps of assembling incoming audio data words which correspond to successive samples of an audio signal into groups nominally of N audio data words where N is the number of audio samples corresponding to the digital video signal to be recorded in one oblique track, allowing the number of audio data words in each group to vary preferably over the range N-1 to N+1 to maintain synchronism of the audio signal with the rotational frequency of the rotary head, coding the audio data words into error-correcting blocks for recording by the rotary head, and associating with each error-correcting block a status code for use on reproduction and which indicates whether the number of audio data words in the corresponding group is N-1, or N+1.

Abstract: In a system for recording and reproducing digital signals on a magnetic tape by using a rotary head, in which signals are recorded as a series of slanted tracks without guard bands, a pilot signal that controls tracking alignment of a playback head is recorded at a particular position in a specific pilot signal record region, independent from the information signal record region. The pilot signal is arranged at first predetermined positions separated from the ends of the slanted tracks in the pilot signal record region on every other one of the slanted tracks and at second predetermined positions separated from the ends of the slanted tracks in the pilot signal record region on the alternate ones of the slanted tracks. An erase signal can also be recorded in the pilot signal record region such that a start position of the erase signal corresponds substantially to a center portion of the pilot signal on the adjacent track.

Abstract: The present invention provides a pancake duplicator for sequentially recording multiple copies of program material on a pancake reel of blank recording tape. The apparatus and method disclosed facilitate and economize the commercial preparation of large numbers of video tape copies of program material. The apparatus includes a video tape drive unit capable of handling large reels or pancakes of raw, unrecorded video tape and transferring the tape past a video recording head to a takeup spool whereby many copies of a particular program are recorded on the pancake. In an alternate form, the recording functions are performed by a conventional recording device using an integrated tape drive capable of transporting tape from a pancake past the recording head to a takeup spool at the appropriate rate.

Abstract: A perpendicular magnetic recording method for recording two kinds of signals on a magnetic recording medium which has perpendicular magnetic anisotropy, recording the first kind of signal on the recording medium with a linear recording density higher than 30 kBPI, and then recording the second kind of signal on that recording track on which the first kind of signal has been recorded, with a linear recording density which is 15 or more kBPI lower than that of the previously-recorded signal, whereby two kinds of signals can be recorded on the same recording medium in such a way that they are superimposed on one another. These two kinds of signals are detected at the same time by one magnetic head and frequency-separated by a reproduced signals processing circuit which is provided with high and low pass filters.

Abstract: A system and method for effecting high density magnetic recordings on magnetic record members such as tape, cards, discs and drums coated with magnetic recoding material. A plurality of different recordings may be provided as overlapping domains or arrays of domains along a single select magnetic record track, thus doubling or additionally multiplying the total amount of information which may be recorded along each record track of a multiple track record member. In one form, one or more magnetic transducers mounted on a common support, may be pivotally driven to variably align their pole pieces and recording or reproduction gaps with a select record track of a record member to provide respective recordings, the domains of each of which are differently aligned from the domains of the others, permitting such different recordings to overlap along the same length of the same track and to be discretely detected by suitably aligned pickups.

Abstract: A method of making a linearity standard magnetic tape includes the steps of providing a rotary magnetic head assembly including a pair of magnetic heads having gaps with different azimuth angles, respectively, and for recording slant tracks alternately on a magnetic tape, a circuit for supplying a first pilot signal of low frequency and a linearity standard signal of high frequency to one of the magnetic heads, and a circuit for supplying a second pilot signal of low frequency and a bias signal of higher frequency than that of the linearity standard signal to the other of the magnetic heads such that the bias signal is outside the recording or reproducing range of the heads and/or the tape.

Abstract: A PCM type record-playback system converts an analog primary signal into a digital signal by sampling and quantizing it and concurrently records it on a magnetic tape with a secondary signal for showing the tape position. The primary and secondary signals are recorded on the same track in a time-divided manner so that recording can be effected with a small number of magnetic heads and the tracks on the magnetic tape can be effectively utilized.

Abstract: A tape position data recording and reproduction method whereby the start points of all programs recorded on the tape can readily be determined merely by playing the tape for a very short time in the reproduction mode. Position data related to a present program and position data related to all subsequent programs are repeatedly recorded at predetermined positions in digital data recording tracks, which are provided as extensions of the tracks containing the video signal. Once the numerical value indicative of the start position of the desired program has been determined, the tape can readily be advanced to that point.

Abstract: A video signal recording apparatus of the type that records a coded audio signal through time division relative to a video signal at one extended end of each of oblique tracks formed on a magnetic tape by helical scanning. The apparatus comprises a circuit for recording a coded video signal in the track region where a coded audio signal is recorded, and a circuit for recording identification data to discriminate between the coded audio signal and the coded video signal on the magnetic tape or recording control data thereon to control playback modes of the recorded signals.

Abstract: In a video tape recorder of a helical scan type, a low frequency index signal and a high frequency signal are simultaneously applied to a full erase head (FE) with the high frequency signal acting as a bias prior to the recording of a video program. After the index signal has been recorded, the application of the high frequency signal is continued to erase a prerecorded material. The high frequency biasing prevents the index signal from interfering with the video signal during playback.

Abstract: In recording an analog signal using two recording heads equally-spaced on a rotating drum, a magnetic tape is wrapped about a guide drum over an angular extent of 90.degree., so that there are recording periods when a head is tracing the tape and periods when no head is tracing the tape. The analog signal to be recorded is converted to a pulse-code-modulated (PCM) digital signal in real-time periods which are longer than the recording periods during which a head traces the tape. The PCM signals are time-base compressed to be slightly less than the rotary head contact interval and additional data such as parity data and cyclic redundancy check codes are added to the PCM signals to form a composite signal, which is written back into a memory system.

Abstract: Apparatus for controlling the speed of advancement of a magnetic tape in a video tape recordor (VTR) of the type including a rotary magnetic head assembly for recording and reproducing an information signal with respect to a plurality of record tracks extending obliquely on a magnetic tape, comprises a recording section including a control signal generator which generates a control signal, a pilot signal generator which generates a pilot signal having a predetermined frequency, an AM modulator which amplitude modulates the pilot signal by the control signal to produce a superimposed or amplitude-modulated signal which is recorded in a control track on the magnetic tape by a fixed magnetic head; and a reproducing section including the fixed magnetic head for reproducing the superimposed signal recorded in the control track on the magnetic tape, a limiter circuit for detecting the pilot signal from the reproduced superimposed signal, an FM detector for detecting a frequency fluctuated component of the detected

Abstract: In a video tape recorder having at least one rotary magnetic head for recording and reproducing a video signal on a magnetic recording tape, a control signal which will be used for controlling the rotation of the rotary head and the movement of the tape is recorded via a stationary head located at a preceding point from the rotary head. The gap of the stationary head extends in the transverse direction of the tape so as to cover the entire or nearly entire width of the tape. Thus, the control signal is recorded on the magnetic tape throughout the entire or nearly entire width thereof, preventing undesirable dropout. By supplying the stationary head with a high frequency erasing current together with the control signal, the stationary head may function not only as a control signal recording head but also as an erase head.

Abstract: An apparatus for processing an audio stereo signal having left and right channels, for use with a video tape recorder having a monoral audio head comprises an analog switch assembly having an electronically controlled switch for each audio channel. A line connects the audio switch assembly to the monoral audio head and control equipment is connected to a video signal terminal of the VTR or video tape recorder. The control equipment utilizes a horizontal sync or synchronization pulse to produce a pair of complementary control pulses. The horizontal sync pulse is processed in a pulse multiplier to step up the frequency to at least twice and preferably about four times the highest audio signal frequency. By alternately controlling the electronically controllable switches to provide a sample of first one and then the other channel, a composite stereo signal can be recorded and then reproduced using the monoral audio head.

Abstract: A method and apparatus are disclosed for enabling the continuous monitoring of recording circuit performance and the automatic optimization of the recording process in a rotary head recorder having a plurality of recording heads. A calibration signal is recorded by each recording head onto the overlap area of a moving magnetic tape medium. A fixed monitor head subsequently detects components of the recorded signal, the magnitudes of which are squared and retained in sample and hold units. The sampled and held values are periodically used to construct an outputted value commensurate with recording circuit performance. Optimization is accomplished by varying the recording drive level of a recording head about a predetermined point during a series of successive overlap periods. A DC error voltage is derived from the respective outputs resulting from such variation, and used to shift the recording drive level of that head towards a point of optimum playback output.

Abstract: The invention provides for the recording of an audio message and subsequent playback thereof and includes a facility for establishing whether the playback message is an authentic reproduction of the original message. The facility is obtained by producing a first data signal indicative of the audio message and recording it together with the audio message and producing a second data signal indicative of the playback message, and comparing the first and the second data signals to establish that the playback is an authentic reproduction of the original message if parity exists between the data signals.

Abstract: A method of recording and reproducing audio signals and corresponding visual signals in parallel tracks extending in the longitudinal direction on a magnetic tape, includes the steps of recording the audio signals in first and second primary tracks on opposite sides of the tape in the widthwise direction thereof; and alternately recording a first visual information signal corresponding to the audio signal in the first primary tracks and a second visual information signal corresponding to the audio signal in the second primary tracks in a single secondary track positioned in the center of the tape in the widthwise direction thereof, the first visual information signal being recorded in first information blocks in the secondary track and the second visual information signal being recorded in second information blocks in the secondary track in an alternating relation with the first information blocks such that only the first visual information signal is reproduced when reproducing the audio signal from the first

Abstract: A servo system provides track following servo information from a buried servo layer disposed under the data recording layer, using the same transducer for simultaneously reading the servo information and writing data. To prevent the voltage generated in the transducer while writing data from masking out the servo information, a dummy voltage having the same magnitude as the transducer voltage is connected so that it cancels the write data voltage in the head.

Abstract: A recorder apparatus comprises a modulator, arranged to be fed with a carrier signal of a frequency at the low end of the audio spectrum (e.g. 80 Hz), for pulse modulating said signal with serialized data corresponding to a time code. A voltage controlled amplifier is connected to the output from the modulator and controlled by an amplitude detector in a separate audio component channel. A mixer is arranged to mix the output from the voltage controlled amplifier and the second audio component channel for feeding to a record head. A play back apparatus which may be integral with the recorder apparatus comprises a low pass filter and a high pass filter arranged to be fed with signals from a read head. A decoder is connected to receive signals from the low pass filter via demodulator to provide time-code signals for a utilization device. The high pass filter is connected to a normal audio channel.

Abstract: The present invention relates to a method and device for associating auxiliary information with principal information, and to a device for monitoring the reproduction of principal information recorded on a track, whereby the auxiliary information is coded in an auxiliary signal of limited frequency and superposed on the principal signal, to be recorded in said track. The device comprises a detection circuit connected at the output of the reader head to detect an auxiliary signal associated with the principal information and occupying a limited range of frequencies and a recording device for recording the auxiliary information. The invention is more particularly applied to the monitoring of the public reproduction of recordings.

Abstract: A single gap transducer simultaneously senses recorded control or servo signals and records data signals. A magnetic medium used with this invention is preferably a single coating magnetic medium. During recording, the recording signal is appropriately subtracted from the readback signal for removing write signal effects on the readback signal. The servo signals are preferably deeply recorded into the magnetic coating whereas the data signals are preferably recorded in an outer surface portion of the magnetic coating.

Abstract: Apparatus for recording and play back of radar video employs a conventional TV video recorder. A multiplexer accepts radar timing signals, synchro data definitive of azimuth, a 60 Hz. reference as well as radar video and formats the signals for recording. A demultiplexer accepts video signals formatted as above, from the conventional video recorder and reformats the signals to drive a conventional PPI display. The video recorder is unmodified so conventional TV video can also be recorded or played back, interspersed, if desired, with the radar video.

Abstract: A first signal to be stabilized in a magnetic record member is recorded via a head having a given maximal gap length and pole pieces of high saturation induction. After the first signal is recorded, the magnetic record member is surface erased for stabilizing the just recorded signal. In a preferred form, the surface erasing is performed by AC erasing via a transducer having a gap length less than said maximal gap length. The pole pieces of the erasing head need not have the high saturation induction of the first mentioned head. After such stabilization, signals can be easily recorded and recovered from the magnetic record member by using transducers with gap lengths less than such given maximal gap length and using the normal ferrite heads having a lower saturation induction than the first mentioned heads. The first signal can be advantageously employed as a position indicating signal in a magnetic record member, such as a storage disk or tape.

Abstract: A system for recording segmented video fields with segment identification codes includes circuitry to encode each segment of a given odd or even field with a different identification code. Further, each corresponding segment of all the other odd or even fields is likewise encoded with the same identification code. Thus, the first segment of any odd or even field has the same identification code which is different from any other identification code appearing for any other segment in any other odd or even field. The same applies to the second and all other segments.

Abstract: Rapid simultaneous multiple access information storage and retrieval system including multiple simultaneously available audio dictation inputs and multiple simultaneously available audio outputs, an array of magnetic recording and playback instruments, and a controller operating under computer command for multiplexing the interchange of audio signals between inputs and outputs on the one hand and the magnetic recorder storage means on the other and at the same time for generating control signals to and from the input and output terminals.

Abstract: A magnetizable anisotropic material layer having a pattern of regions of differently aligned material has an initial pattern of remanent magnetization, when manufactured by applying directional magnetic fields. This pattern is not easily restored, and is generally impossible to restore, after demagnetization or remagnetization. By preserving the residual pattern and selectively removing it in use by the application of a magnetic field, a security feature is provided. A secure document system using such a feature is provided.

Abstract: A PCM recording apparatus is disclosed in which digitized left and right channel sample signals each having error detecting bits and a signal indicative of a correlation such as sum or difference of the two samples are recorded on a record medium in a predetermined arrangement, and an error in coding is detected from the correlation signal.

Abstract: The invention relates to magnetic recording. A method of superposing a modifiable magnetic code on a fixed bar code magnetizes the bars in two different directions by means of a write head. There is the provision for synchronising the application of write signals to the write head with the passage of the bars of the bar code and the system may include a bar code reading head which reads a code moved by a conveyor belt and which causes an image of the bar code to be stored in a shift register with each bar and each space of the bar code being represented by several successive 1's or 0's. The write head then includes a read winding which triggers (via) reading of the image, and the image is gated into a code generator that writes when an image bar is present thereby writing magnetically onto the real bars of the bar code.

Abstract: Apparatus is disclosed for long-term ambulatory monitoring of blood pressure by an auscultation method, employing a pressurizable cuff and requiring no intervention by the patient. Heartbeats are sensed by ECG electrodes, and a microphone is used to sense the Korotkow sounds as the pressure in the cuff is varied. The presence or absence of a Korotkow sound within a preset interval following each heartbeat is used in determining when the cuff pressure equals the systolic and diastolic pressures. Those pressures are determined in each cycle of operation and are recorded on a continuously-running portable tape recorder, along with the ECG signals. In each cycle of operation, the initial pressure to which the cuff is inflated is based on the systolic pressure measured in the immediately preceding cycle. The pressure in the inflated cuff is thereafter stepped downward in small discrete decrements triggered by successive heartbeats during the measurement phase of each cycle.

Abstract: Wide band measured data signals are recorded synchronously with television signals by time and/or frequency multiplexing techniques. Measured data signals are scanned by a multiplexer, converted to digital form, and temporarily stored. Signals from the store together with auxiliary information signals are converted from parallel to serial form and suitably coded for multiplexing. For time multiplexing, the picture may be limited to square form to increase the bandwidth available for the serial information signals. With either form of multiplexing, helical scan magnetic tape recording is preferably employed. Playback circuits effect separation of picture from information signals through a discriminator for time multiplexed signals and through a filter for frequency multiplexed signals. Provision is made for insertion of special lines in the television picture and for the retrieval thereof on playback.

Abstract: A multitrack recorder is disclosed in which each of a plurality of parallel data signals is mixed with an additional signal corresponding to a digital code indicative of the real time at which the data is received. Each of the mixed signals is then conventionally recorded on a separate track of a suitable record medium. The recorder includes a circuit which shifts the phase of the recorded data signals with respect to each other, while keeping the phase of all recorded time signals in phase with each other. Upon playback, the signals from all tracks are added together. The out-of-phase data signals from each track tend to negate each other and the in-phase time related signals reinforce each other, thus becoming readily detectable. Preferably, the digital time related signals are encoded as two frequencies, both of which are below the band width of the data signals, such that frequency filters may also be employed to enhance the recovery of the time code.

Abstract: Overlapping, minute regions of magnetization in a recording medium, which are produced during recording and cause distortion of the played back signal, are reduced by encoding the signal in a pulse signal. The time between pulses is varied according to the amplitude of the signal to be recorded, and when this pulse signal is recorded, the minute regions are reduced to elemental size. Thus they overlap less and do not distort the reproduced signal by offsetting the zero level.

Abstract: The invention relates to a magnetic coding method. It is characterized by e superposing of a first binary message at a given frequency and a binary message at double frequency in space phase. Application to credit cards with a magnetic track.

Abstract: A method and a video tape recorder apparatus having an encoder for serially pulse width modulating each of the normal frame-reference pulses with a bit of an elapsed record time signal and for recording the signal onto the frame-reference track of a video tape and a decoder for, during playback of the tape, extracting from the reproduced signal the frame-reference pulses and the elapsed record time signal and for generating therefrom a frame count signal.

Abstract: A video recording disk is adapted to be rotated at a uniform angular velocity and to have bit positions of substantially equal length along a track, and the longer outer tracks are given more storage positions than the shorter inner tracks. Variable numbers of frames are located on each track revolution, depending on the data capacity of the track. Frames are divided into data units that correspond to a few horizontal lines, and frames on the same track are interlaced so that the data units of each frame are distributed evenly around the track revolution. The associated record player has simplified data storage requirements, particularly for freeze frame display of the television picture and for playing disks that hold video information in a data compression format.

Abstract: A magnetic audio tape comprises at least two tracks in one direction of advance of the tape. Each of the tracks has pre-recorded sections at sufficient intervals therebetween, with the recorded sections of one of the tracks being staggered with respect to the recorded sections of the other track in such a manner that all of the recorded sections of the tracks are not opposite to each other in the transverse direction of the tape. Each of the recorded sounds in the recorded sections of one track is closely related as a learning aid to the recorded sound of the staggered adjacent recorded section of the other track.

Abstract: This invention relates to a system that permits a video tape recorder to simultaneously record a plurality of independently occurring events. The system causes the events to be multiplexed before they are recorded and a coded signal to be recorded on the tape so that when the tape is played back, the events may be demultiplexed in the same order that they were recorded.

Abstract: Information is recorded on a magneto-optic medium having a predominant proportion of preferred domain orientations with a substantial component normal to a recording surface thereof, by using a fringe field component from a magnetic-head. At least one magnetic head is utilized and such head is passed over the medium in a predefined track pattern which incorporates substantial overlapping of adjacent track portions. With such overlapping, only a residual portion of a track as originally laid down remains unerased in the final recording, and such residual portion is narrow in relation to head width. A high-resolution optical playback device is then preferably employed to extract the recorded information from the compact residual track.

Abstract: A system for retrievably providing a video display of a pictorial information message on a video display device from video information stored, such as on a video tape, in a plurality of frames, unique pictorial information being stored in each frame for display thereof in response to a request therefor, the frames each including a plurality of segments with one displayable pictorial information message being contained in each segment, the selected segment being retrievable for individual display of only this requested pictorial information containing frame segment. The video tape storage media in addition to the video track upon which the pictorial information is stored, contains an audio track having unique frame identification code information stored thereon for providing a frame location signal which is utilized to retrieve the frame.

Abstract: A system comprising a playback unit and an associated long-playing record on which sound information is recorded in a time division multiplex code on several tracks. Upon reproduction the same track is scanned n times with the aid of a beam of light before this beam of light is directed to the next track. With the aid of a sampling gate the pulses comprising the sound information in time division multiplex code and associated with a first sound channel are sampled with the aid of said sampling gate while during a second revolution pulses from a second sound channel etc. are sampled.In order to operate this sampling gate in synchronism with the scanning of said pulses the playback unit comprises first synchronizing means responding to pulses also comprising the sound information. Furthermore, at the commencement of each track, starting pulses are provided to which second synchronizing means respond.

Abstract: This abstract describes a system for the field recording of seismic data in which a plurality of geophone outputs are connected to an array terminal. Each geophone is connected to a fixed gain differential amplifier. A shifting function is produced which is added to the amplified geophone signal to form a sum signal which goes to an axis crossing coder, (AXC). On a first command from an array controller in a distant recording unit, the AXC is commanded to produce axis-crossing-coded pulses of the instantaneous sum signals. These pulses are stored in a parallel-to-serial converter inside the array terminal. On a second command from the array controller the converter reads out as a train of serial bits, the pulses stored in the converter. This train of single bit signals is transmitted to the array controller by a single pair of conductors, and stored on a magnetic recording means.

Abstract: Apparatus for multiplexing a large number of digital signals onto a few aog channels using a level code encoded multiplexer. Each digital signal to be multiplexed is assigned a unique reference level to represent a logical "one", with all digital inputs assigned the same zero ground as a base line for a logical "zero".

Abstract: A method and means for filtering and intensifying signal components of a desired predetermined period of repetition wherein a plurality of recording heads in tandem arrangement are provided, adjacent recording heads being equally spaced from each other. A magnetic tape is drawn past the recording heads at a constant velocity. The recurring signal component of desired period of repetition is delivered to the recording heads simultaneously and in such a way that the portion of the magnetic tape upon which each individual recording of the desired signal component is made by each recording head reaches the next recording head simultaneously with the next such signal component. As a result the amplitude of the desired signal component is increased on the magnetic tape and the amplitude of all other periods of repetition is relatively reduced. The summated signal can be reproduced by means of a playback head and an appropriate readout means.