Showing papers on "Magnetic tape published in 1983"

Calculation of anomalous scattering factors at arbitrary wavelengths

Abstract: A Fortran program and photoelectric cross section data file are available for calculating anomalous scattering factors at arbitrary X-ray wavelengths. The two files can be obtained by sending a blank magnetic tape to the author along with instructions for preferred tape format.

Magnetic recording medium

Abstract: PURPOSE:To use various types of magnetic recording media with high interchangeability for various types of recording devices, by recording previously magnetic characteristic information at a part of a magnetic recording medium. CONSTITUTION:A format contains a magnetic tape 1 itself, a part 2 where the bias current and the equalizer time are recorded as the magnetic characteristic information, and an unrecorded part 3 which can be used by a user. It is ideal to record the magnetic characteristic information by converting the bias current into a coefficient since the absolute current value of the bias current differs by magnetic heads. For a magnetic disk 4, the optimum recording current coefficient is recorded as the magnetic characteristic information at a part of the most outer circumference of an encoder and on the basis of the format. A magnetic head 7 functions as a magnetic sensor which reads the magnetic characteristic information of the disk 4 and also serves as a reading/writing head which can function as a writing head to record the data on a magnetic disk 5. An amplifier 8 converts the signal which read the magnetic characteristic information through a magnetic head 7 into the pulse signal.

Rotary head assembly

Abstract: In a rotary head assembly which has a stationary cylinder (21) with a fixed cylindrical part, and a rotatable rotary member (19) of a diameter substantially equal to that of the cylinder (21) which is arranged with a very small gap on the same shaft as the cylinder (21) and holds a magnetic head (29) so that a magnetic tape is helically wound and fed thereon, a pump-out type of spiral group (20) is formed on part or all of the periphery of either of the surfaces of the opposed rotary unit formed between the cylinder (21) and the rotary member (19), a floating force due to pneumatic pressure is generated, not only on the rotary cylinder, but also on the stationary cylinder so that the feeding of the magnetic tape is stable and smooth, thereby basically eliminating the phenomena of tape flutter and adhesion, and also tape damage or cylinder wear due to friction

Magnetic recording medium

Abstract: PURPOSE:To increase greatly the recording density of a data recorder/reproducer, by using a staircase wave generating circuit to convert a digital data into a staircase wave having a modulated period and then to record it to a recording medium. CONSTITUTION:The staircase waves of different periods in accordance with 1 or 0 of the signal at a terminal Q which is obtained by latching a data signal (a) by a latching circuit 11. In other words, the half period T of the staircase wave is short and long when the data (a) is set at 0 and 1 respectively. Then the staircase wave is recorded on a magnetic tape 3 by a tape recorder 7. In the reproduction mode, an output signal (c) is supplied to a buffer 14 of a comparator 5. At the same time, the top or bottom point of the signal (c) is held by the values of a diode and a capacitor. Then the amplitude center potential of the signal emerges at a capacitor C4 through a resistance. An operational amplifier 15 compares the signal with its amplitude center to extract a square wave (d) which has a short period to a signal 0 and a long period to a signal 1 respectively. Thus, the recording density is greatly increased.

Magnetic tape drive with adaptive servo

Abstract: An improved drive for a magnetic data storage tape is described which features direct coupling of the tape from a machine to a file reel without interposition of vacuum buffers or spring loaded tension control devices. Control of the current supplied to motors driving the file and machine reels is performed by a microprocessor in response to information derived during an initialization routine performed at first mounting of a reel of tape upon the drive and in response to continuously generated velocity information generated by tachometers on the motor shaft. The absolute position of the tape can at all times be known to the microprocessor and the tension of the tape can be controlled by control of the supply of current to the motors. In a preferred embodiment, a solid state buffer memory is provided to accept data from a host computer during the time the tape drive comes up to speed. By use of the initialization routine to determine motor losses, windage, brush and bearing wear, and the moment of inertia of the motor/reel systems, and the instantaneous tachometer data, direct sensing of tape tension can be avoided, thus eliminating mechanical parts in favor of sophisticated electronic control means.

Digital data error correction method and apparatus

Abstract: Controller circuitry for a serially-recording magnetic tape drive which is capable of correcting writing errors by rewriting the portions of the data which have been erroneously recorded. Write circuitry in the controller breaks a conventional data record up into one or more blockettes, each of which is assigned a unique sequential blockette number which is recorded on the tape along with the data. After each blockette has been serially recorded sequentially by blockette number on the tape, it is immediately read to check whether it has been properly recorded on the tape. If the blockette has been recorded improperly, the read process directs the write circuitry to rerecord the blockette information at the tape position then under the write head. The recorded blockettes may be out of sequential order since the rerecorded blockette may be located several blockettes after its initial erroneous writing. The data is placed back in sequential order by the read process. As blockettes are read from the tape, they are placed in a buffer memory in the controller. The read circuitry then transfers the data to the host computer system in the order specified by the blockette number and therefore reconstructs the data even if blockettes have been rewritten out of sequence.

Personal electrocardiology recorder

Abstract: A personal electrocardiology recorder having body electrodes for detecting heart action signals, an amplifier, a signal converter for converting the detected signals into signals recordable on magnetic tape, and a tape recorder, wherein the body electrodes are disposed directly on the tape recorder casing, the measuring and reference electrodes being disposed on a first wall and the earthing electrode being disposed on a wall other than the first wall, and wherein a microphone for recording a spoken description of the symptoms is provided. The recorder can be carried permanently by patients and can be switched on during the occurrence of corresponding symptoms for recording a diagnostically relevant ECG phase.

Device for positioning a magnetic head to various tracks of a magnetic tape

Abstract: A device for positioning a magnetic head into an operative position relative to a multi-track magnetic tape in a magnetic tape recorder. A magnetic head is disposed at one end of a magnetic head carrier while the opposite end of the head carrier is axially and laterally moveably mounted on a shaft attached to the tape recorder housing frame. A motor-driven worm gear engages a worm wheel mounted in an axially displaceable manner along the shaft. A spring mounted on the shaft urges the head carrier against the worm wheel so that upon rotation of the worm, the worm wheel is displaced along the shaft and moves the magnetic head perpendicularly to the running direction of the magnetic tape. A stop member is positioned adjacent the head carrier to prevent rotation of the head carrier during rotation of the worm wheel. In certain embodiments, the head carrier is pivotally mounted on the shaft in order to selectively pivot the magnetic head away from the operational working area thereof. The magnetic head carrier is seated in a bearing plate formed of a resilient material and on the shaft. After releasing the fastening of the bearing plate at one end thereof, the magnetic head and magnetic head carrier can be readily replaced by another magnetic head and carrier and precisely positioned by reattaching the bearing plate over the shaft.

Method and apparatus for a magnetic recording/reproducing

Abstract: A helical scan type magnetic tape recording/reproducing apparatus for recording/reproducing information, for example, a large amount of time-compressed audio PCM signals on a plurality of information tracks disposed in parallel to the direction of the tape running. Each of the time-compressed audio PCM signals are recorded with one of four frequencies of a pilot signal on a selected information track, and each of the time-compressed audio PCM signals recorded on the information tracks can be selectively reproduced from the corresponding information track. The apparatus includes a circuit for generating a plurality of track indicating pulses which respectively correspond to the information tracks and are phase-locked to the rotation of the rotating heads, and a circuit for selecting one of the track indicating pulses, which is supplied to control time compressing/expanding of an audio signal.

Apparatus for recording additional video signals in a helical scan operation

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.

System for regulating data transfer operations

Abstract: A magnetic Tape Peripheral Controller (data link processor 20t) is used to manage data transfer between a peripheral tape unit (TCU 5ot) and a main host computer (10) A buffer memory (22) in the peripheral controller (20t) is provided with a status counter unit (34c) to monitor the amount of data-in-transit which momentarily resides in the buffer (22) The status counter unit (34c) provides output signals to the peripheral-controller (20t) to elicit action calling for more data from the peripheral tape unit (50tc) or from the host computer (22) or to indicate that the amount of data in the buffer memory was loaded before the main host computer responded to allow the acceptance of it

Method and apparatus for compensating for tape jitter during recording and reproducing of a video signal and PCM audio signal

Abstract: Apparatus for recording and reproducing an information signal comprised of a video signal and an audio signal in a plurality of successive tracks on a magnetic tape, includes a recording section comprised of a PCM processor which converts the audio signal to a PCM audio signal and compresses the same, a dummy signal generator for compensating for tape jitter by generating a dummy signal and supplying the same to the PCM processor where the dummy signal is added both before and after each portion of the compressed PCM audio signal to be recorded in an overscan section of each track, and a magnetic head assembly which records the video signal in a main section of each track and each portion of the compressed PCM audio signal and dummy signal added thereto in the overscan section of each track; and a reproducing section comprised of a magnetic head assembly which scans the tracks to reproduce the information signal recorded therein, a switch assembly which separates the video signal reproduced from the main section of each track and the PCM audio signal reproduced from the overscan section of each track; a PCM processor which converts the PCM audio signal to the original analog audio signal and a timing signal generator for compensating for tape jitter by enabling the PCM processor only during a period slightly greater than the period of the PCM audio signal recorded in the overscan section of each track.

Variable speed playback controller for a video tape recorder

Abstract: A magnetic tape transport controller for a magnetic recording and reproducing apparatus in which a pilot signal for tracking control having four different frequencies is recorded on a magnetic tape by a rotary magnetic head and the magnetic tape is transported in a playback mode at a different tape speed than that in a recording mode. The tape transport controller has means for detecting an amplitude change of a specific one of signals derived by frequency-converting a reproduced pilot signal and controlling the tape speed such that the frequency of the amplitude change is maintained at a predetermined frequency. It also has a phase control loop to control the tape speed such that a phase of the specific signal coincides with a phase of a reference signal. In the playback mode in which the tape is transported at the different speed than that in the recording mode, frequencies of a local pilot signal used to frequency-convert the reproduced pilot signal are switched in the opposite order to that of the switching of the frequencies in the recording mode. A detection circuit which detects a difference between two frequency converted signals of different frequencies and amplifies the difference inverts a polarity of an output signal for each track switching in a standard speed playback mode and does not invert the polarity in a variable speed playback mode.

Apparatus for threading magnetic tape in a magnetic tape transport

Abstract: Apparatus for threading cartridge magnetic tape over a predetermined data processing path to a takeup reel. A cam track is provided in a cover over the path. The track has a beginning point for positioning a longitudinal cam member into engagement with a leader block exposed through an opening in the cartridge. The track terminates over the takeup reel rotational axis. A bifurcated linkage member is connected at one end to said longitudinal cam member, and to a drive motor. Rotation of the linkage member positions the longitudinal cam member between ends of the track engaging the leader block and threading it through the path and into a slot on the takeup reel.

Automatic tape threading system for use in a tape transport system

Abstract: A small, high performance magnetic tape transport system for use in recording and reproducing data is adapted to receive a cartridge in which a single supply reel for the magnetic tape medium and the magnetic tape are carried. The cartridge is capable of being easily loaded into the transport system for recording (writing) and reproducing (reading), and is also easily ejected from the system for storage or replacement. A driving mechanism for the reel in the cartridge and a permanent take-up reel or hub are carried by the transport. The separate cartridge driving mechanism and take-up hub are each driven by their own separate motor system. In the embodiment disclosed, means are taught for automatic threading of the tape using a semi-rigid leader having a coupling portion attached to the take-up hub, the to-be-threaded tape including a complimentary coupling portion. The transport system defines a specific path for the leader to follow from the take-up hub so that it will reach and automatically couple with the tape and then be rewound on the take-up hub. However, a different path is followed by the tape.

Magnetic recording/reproducing apparatus

Abstract: A magnetic recording/reproducing apparatus for sequentially recording each of four pilot signals of different frequencies on each video track to be multiplexed with a video signal and reproducing the video signal and the pilot signals at which time the pilot signals are separated from the video signal and used as a tracking signal to control the transport speed of the magnetic tape, wherein upon reproduction the levels of the pilot signals reproduced from the right and left adjacent video tracks are detected and one of the reproduced pilot signals from the right and left adjacent tracks is controlled in its level so that the tape travelling speed is controlled to make the center of the video head scan the same position on the track as upon recording

Magnetic recording and reproducing apparatus

Abstract: A magnetic recording and reproducing apparatus comprises a drive mechanism for running an endless magnetic tape of less than 300 m at a higher speed than 5 meters per second; a restricting member interlocking with the roll of said rapidly moving endless magnetic tape wound on a reel to apply a force against a centrifugal force generated on the tape roll so as to prevent it from being shaken unnecessarily; and a stationary magnetic head so arranged that the head is stational in a tape running direction and intermittently movable in a tape width direction to record frequency-modulated video signals in, and reproducing said signals from, the magnetic tape.

Magnetic tape recorder

Abstract: In an exemplary embodiment a cassette provided with the magnetic tape is inserted in a longitudinal direction into an insertion channel. During and/or after the insertion of the cassette, a magnetic head carrier provided with a magnetic head is pivoted from an idle position into an operating position in which the magnetic head contacts the magnetic tape. The pivotal movement is effected by a lever linked to the magnetic head carrier. The lever is actuated by a connecting rod which is linked to a cover for closing the insertion channel. The movement of the lever by the connecting rod ensues via a rotatably mounted swivel arm. When the cover for the insertion channel is opened, the magnetic head is pivoted back into its idle position and the cassette is simultaneously partially ejected from the magnetic tape recorder by the swivel arm.

Recording and reproducing apparatus for a video tape recorder

Abstract: In a video tape recorder of the two-head helical scan system, a wrap angle of a magnetic tape (7) around a rotary head mechanism is set to more than 180°, e.g. about 220°, and an overlap recording section is provided in a recording track. A time compressed audio signal and a pilot signal for the tracking control are recorded in the overlap recording section. A frequency modulated luminance signal, low-frequency converted carrier color signal, frequency modulated audio signal, and pilot signal are mixed, and this mixed signal is recorded in another section of the recording track. Regulator means (34; 264, 271; 340) is provided to conjointly set the recording current levels of the low-frequency converted carrier color signal, frequency modulated audio signal, and pilot signal which are mixed to the frequency modulated luminance signal and recorded. The recording current levels of the time compressed audio signal and the frequency modulated luminance signal are respectively and individually set. When different kinds of magnetic tapes (e.g. metal powder tape and metal evaporated tape) are used, a level switching circuit (352) is provided to switch the recording level of the signal of which the low-frequency converted carrier color signal, frequency modulated audio signal and pilot signal were mixed in accordance with the kinds of tapes.

Apparatus for decoding video address code signals

Abstract: Apparatus for decoding digitally-coded address signals embedded in video signals recorded on magnetic tape is disclosed The apparatus can properly decode the address signals at both slow and fast tape speeds and utilizes a variable-frequency oscillator to generate timing signals for decoding the digitally-coded address The address signals encoded on the magnetic tape normally include an error code which can be detected by conventional error checking circuitry and used to check whether the address signals have been correctly received The oscillator frequency is adjusted in accordance with an error signal generated by the error checking circuitry until error-free detection of the address signals is achieved

Seismic data transcription system

Abstract: A transcriber system for receiving previously recorded data in a first medium and outputting the data in a second medium, and which includes at least one input device for receiving the data in the first medium, an output device for outputting the data in the second medium, a control and processing device which controls the input and output devices for a selected mode of transcription and in one embodiment, for selected processing of the data in the field. In one embodiment, the transcriber system receives seismic data from tape cartridges and/or solid state memory devices and outputs the seismic data onto a magnetic tape for later processing and analysis or transmission to a remote facility via a satellite link. The transcription system can include a printer/plotter for analysis of different seismic data recording and processing arrangements in the field.

A locking device for a cover of magnetic tape cartridge

Abstract: A locking device for a cover of a magnetic tape cartridge (3) for locking a pivotable cover (4) for covering magnetic tape inlet and outlet ports (16 and 17) of the magnetic tape cartridge, including a projection (70) formed on an arm (67) for pivotally supporting the pivotable cover which is engageable with an engaging claw section (74) of a locking member (73) which further includes an operation section (75) and a resilient section (76) The locking member is pivotally supported on a magnetic tape cartridge case (3) and urged by the biasing force of the resilient section to bring the engaging claw section into engagement with the projection The operation section of the locking member is located in a position in which it is capable of cooperating with an unlocking pin moved from three directions, to thereby give latitude to the process for loading a magnetic tape cartridge on a magnetic recording and reproducing apparatus

Magnetic tape cartridge with increased data track packing density

Abstract: A digital magnetic recording tape cartridge has a housing that permits use of greater than 1/4-inch wide tape which, in turn, increases data recording packing density over standard 1/4-inch tape cartridges. The tape cartridge is the belt-driven type having a flexible elastic endless belt that applies tension to tape on the supply and take-up reels to move the tape. Rotation of a driving roller causes the belt to drive the tape reels and move the tape between the reels. A magnetic head of the tape transport engages an exposed portion of the tape in the cartridge for reading or writing data on the tape. In a preferred embodiment, the tape is 1/2-inch wide. The number of data tracks is substantially increased by the wider 1/2-inch tape. The cartridge housing has a base plate with a stepped on recesses that accommodates the wider 1/2-inch tape and the wider supply and take-up reels, tape guide rollers, and tape guide pins. The cartridge has flanges along both sides of recessed grooves in the sides of the cartridge that permit the cartridge to be inserted into a tape drive capable of interchangeably receiving the 1/2-inch tape cartridge of this invention or the standard 1/4-inch tape cartridge.

Method of identifying magnetic tape as tape for journal

Abstract: In the on-line system, information called journal indicative of the hysteresis of process are written in turn in magnetic tape. At each process, journal information is added with information indicative of journal and the date on which the journal information was written. At the time of system resuming process after system down, the information added to journal at each process is read in order that the magnetic tape being read is decided to have recorded thereon the journal to be used for the system resuming process.

Magnetic storage device

Abstract: PURPOSE:To detect defective recording quickly, by providing a reproducing head on the same track near a pair of recording heads of a helical scanning type magnetic tape device and comparing a recorded signal stored in a storage section with a reproduction signal. CONSTITUTION:The recording heads 5, 7 and reproducing heads 6, 8 in contact on the same track near the heads 5, 7 are provided in the interval of 180 deg. on a helical cylinder. A signal from a bus line 11 is interfaced 12 and stored in an RAM17, an encoded 13 recording signal is amplified 14 and recorded on a magnetic tape with the head 5 or 7. The head 6 or 8 reproduces a signal just recorded with a small delay and amplifies 15 and decodes 16 it to a coincidence detection circuit 18. The circuit 18 compares the data of the RAM17 with the data of the decoder 16 for one track's share and an effective signal X is outputted when they are coincident. In case of dissidence, an ineffective signal Y is outputted and recorded again with the data in the RAM17. Thus, the recording with high reliability is executed easily.

Video signal reproducing device

Abstract: A video signal reproducing device includes a magnetic head for reproducing the video signal recorded in slant tracks on a magnetic tape, a transport mechanism for driving the tape at a controllably varied speed, and a tracking control circuit for supplying tracking control signals to the magnetic head whereby the head tracks the recorded video signal. The device further includes a system control circuit for controlling the transport mechanism to drive the tape at a selected playback speed, and a display connected to the system control circuit for indicating a relationship between the predetermined duration and a duration of the reproduced video signal as played back with the tape driven at the selected playback speed.

Digital tape transport for selectively recording in either a parallel or serial mode

Abstract: A magnetic tape transport for recording digital data. The tape transport is selectively operable in either a parallel write mode for recording concurrently along multiple tracks in a standard format or a high density serial write mode for recording along one track at a time, the multiple tracks being recorded in sequence in a serpentine format. The transport uses standard multitrack read and write heads with each head having N transducers, where N is a positive integer greater than 1, supplemented by an additional multitrack read head or write head with N/2 transducers for N even or (N-1)/2 transducers for N odd, so that for either direction of tape movement, the tape will first pass a write head and then a read head. When moving in a first direction (forward) the tape will move past the write head and then past the first read head. When moving in a second (reverse) direction, the tape will move past the write head and then past the second read head, thus permitting data to be read for verification after writing for either direction of tape movement. When operating in the high density serial mode, the heads are selectively enabled to serially record data along a single track at a time with the tracks being serially recorded in a serpentine format, i.e., in a forward direction along track one, a reverse direction along track two, a forward direction along track three, etc.

Video tape recorder

Abstract: A video tape recorder includes a cylinder provided to rotate about its axis. A magnetic tape moves along a portion of the cylinder surface such that the cylinder surface obliquely traverses the magnetic tape. At least one pair of magnetic heads are mounted on the cylinder surface for recording and reproducing video signal on the tape, and another pair of magnetic heads are mounted on the cylinder for recording and reproducing audio signal on the tape.

Block counter system to monitor data transfer

Abstract: A system is disclosed which is usable to monitor data-being-transferred in terms of blocks (512 bytes or 256 words) wherein the data-being-transferred is temporarily stored in a RAM buffer memory. Thus, data blocks being transferred from a main host computer to a peripheral terminal unit (as a magnetic tape unit) via a Tape Control Unit (TCU) can be monitored to indicate, at certain intervals, the balance of data residing in the buffer memory during moments between cycles where data has been shifted into and/or shifted out of the buffer memory.