Flux Gate Patents (Class 360/111)
  • Patent number: 4819097
    Abstract: An audio signal recording/reproducing system is used in a time-lapse video tape recording device for time-lapse recording a video signal on a magnetic tape at predetermined time intervals. The audio signal recording/reproducing system comprises a memory which stores an audio signal and time-compresses the stored audio signal to output it as the time-compressed audio signal at one field period, and a magnetic head for recording the one-field period audio signal on the magnetic tape. Each of the audio signal recording tracks recorded on the magnetic tape is arranged between two adjacent video signal recording tracks. The audio signal recorded on the magnetic tape is read out by the magnetic head and stored in the memory again. The audio signal stored in the memory is expanded in its time-base to be reproduced as continuous sound.
    Type: Grant
    Filed: May 10, 1988
    Date of Patent: April 4, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Nobuo Azuma, Masaru Takahashi, Akira Shibata, Katsumi Mikamo
  • Patent number: 4783703
    Abstract: In a field/frame conversion system in which a field signal recorded on a track of a recording medium is repeatedly reproduced, a field signal delayed by 1/2 horizontal scanning duration and a directly provided field signal are alternately selected by a switch at each vertical scanning duration, and one of the field signals is formed by an arithmetic mean of a signal delayed by 1 horizontal scanning duration and a directly provided signal, to provide a frame signal, a flicker preventing circuit device in a field/frame conversion comprises a circuit provided in a front stage of an arithmetic mean circuit of the field/frame conversion system for bringing a gamma value of the field signal to 1, and a gamma circuit provided in a rear stage of the arithmetic mean circuit for returning the gamma value of the field signal to its original value.
    Type: Grant
    Filed: March 31, 1986
    Date of Patent: November 8, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventors: Makoto Murakoshi, Hitoshi Hirobe, Hiromasa Hino
  • Patent number: 4783704
    Abstract: The skip-field video recorder of the invention maintains the temporal sampling rate of the original incoming video signal by including information from both the odd and even video fields of each frame in a single composite recorded video field. During playback, an odd and an even video field are synthesized from the single composite recorded video field to generate a complete video frame.
    Type: Grant
    Filed: December 10, 1986
    Date of Patent: November 8, 1988
    Assignee: Eastman Kodak Company
    Inventor: David L. Funston
  • Patent number: 4774599
    Abstract: By employing field store memories, a skip-field video recorder records odd and even fields of different frames and then plays back full frames reconstructed from the recorded odd and even fields, thus achieving maximum vertical resolution in the playback video image.
    Type: Grant
    Filed: January 2, 1987
    Date of Patent: September 27, 1988
    Assignee: Eastman Kodak Company
    Inventor: Hans-Peter Baumeister
  • Patent number: 4774597
    Abstract: Two pairs of opposing magnetic heads mounted in quadrature on a rotary drum simultaneously receive two independent video channels, one channel being quadrature-delayed with respect to the other. The heads simultaneously record the two video channels in adjacent tracks on a video tape moving at twice the normal linear tape speed. To playback one of the two simultaneously recorded video channels, the two pairs of heads retrace their respective recorded tracks while the video tape moves at twice normal linear speed, but only one opposing head pair is connected to playback circuitry. In an alternative embodiment, the tape moves at standard speed while the heads skip-field record the two quadrature-delayed video channels.
    Type: Grant
    Filed: July 28, 1986
    Date of Patent: September 27, 1988
    Assignee: Eastman Kodak Company
    Inventor: Donald M. Harvey
  • Patent number: 4758900
    Abstract: A field/frame signal conversion method in a magnetic picture recording for use in an electronic still camera and the like is disclosed which prevents the lowering of a SN ratio of a field signal and the occurrence of flicker caused by delaying the field signal. In the field/frame signal conversion method, an operation of delaying the field signal for the field/frame signal conversion as well as for an arithmetic mean operation, performed for the purpose of preventing the occurrence of the V jitter caused by the field/frame signal conversion, is carried out in the frequency modulated condition of the field signal. Then the arithmetic mean operation is performed after the field signal is frequency demodulated and before it is de-emphasized.
    Type: Grant
    Filed: July 15, 1986
    Date of Patent: July 19, 1988
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Yasuhito Kobayashi
  • Patent number: 4758901
    Abstract: In a skip-field video recorder, the audio signal of every field is continuously recorded. The audio signal of each skipped video field is stored in an audio field store memory and then unloaded during the recording of the next (unskipped) video field. The unloaded audio signal is multiplexed with the current incoming audio signal and recorded therewith. Alternatively, the audio signals of both the skipped field and the unskipped field may be compressed and recorded in an extended portion of each video tape track.
    Type: Grant
    Filed: October 28, 1986
    Date of Patent: July 19, 1988
    Assignee: Eastman Kodak Company
    Inventor: Robert R. Eckenbrecht
  • Patent number: 4751598
    Abstract: A thin-film, cross-field, closed-flux, anisotropic electromagnetic field device for recording images on and reading them from magnetic media, such as a magnetic disk, tape or drum. The device is characterized by two orthogonally related conductors which couple electromagnetically with magnetic coupling structure. One portion of such structure substantially completely surrounds one of the conductors relative to the direction of current flow therein, this portion being anisotropic, and having an easy axis of magnetization that parallels such current flow. With the device in use, this easy axis is intended for operative coupling alignment normally relative to the recording surface in the selected recording medium.
    Type: Grant
    Filed: February 1, 1985
    Date of Patent: June 14, 1988
    Assignee: Censtor Corporation
    Inventor: Harold J. Hamilton
  • Patent number: 4721864
    Abstract: An inductive pulse generator for converting a rotary movement into a frequency proportional therewith. The pulse generator includes a measuring wheel (1) provided with poles (3) of magnetic material evenly distributed over the circumference of the measuring wheel. The pulse generator further includes a stator (4) provided with a magnetic core (6) with plate-shaped pole shoes (10) in a coil carrier (8) out of which end portions (12) of the pole shoes (10) project. The end portions (12) face the measuring wheel (1). A coil (7) surrounds the magnet core (6), at which coil (7) a pulsating voltage can be picked off with a frequency proportional to the number of revolutions of the measuring wheel (1), outside the area of the pole shoe (10) end portions (12) facing the measuring wheel (1). The thickness of the pole shoes (10) is increased by additional magnetic material (11) so as to increase the pulsating voltage which can be picked off at the coil (7).
    Type: Grant
    Filed: December 5, 1986
    Date of Patent: January 26, 1988
    Assignee: Alfred Teves GmbH & Co. OHG
    Inventor: Andre Goossens
  • Patent number: 4707733
    Abstract: An information recording disc has a connecting region formed between a parallel program recorded region containing a plurality of parallel information programs and a single program recorded region containing a single information program which is to be reproduced after one of the parallel information programs is reproduced.
    Type: Grant
    Filed: March 25, 1985
    Date of Patent: November 17, 1987
    Assignee: Victor Company of Japan, Ltd.
    Inventors: Tatsuya Shinyagaito, Terumasa Kuramoto, Toyotaka Machida, Kikuji Saito, Shunichi Shichijo, Tooru Yamagishi, Kazuyoshi Ishii, Yoshinao Kobayashi, Atsumi Hirata
  • Patent number: 4680657
    Abstract: A magnetically recorded signal on a magnetic recording medium is reproduced in response to a magnetic field produced thereby by applying a DC biasing magnetic field along the magnetic path of the core of a coil-supporting magnetic head, and adding a high-frequency magnetic field of a small amplitude to the DC biasing magnetic field. The DC biasing magnetic field is produced by passing a DC biasing current through a DC biasing coil on the core, and the high-frequency magnetic field is produced by passing a high-frequency current through another coil on the core.
    Type: Grant
    Filed: September 5, 1985
    Date of Patent: July 14, 1987
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Hiroichi Naito
  • Patent number: 4658319
    Abstract: A time lapse video recorder includes auto monitoring circuitry for ensuring that proper recordings are being made. During the time between intermittent recording of fields by the time lapse recorder, the recorder is switched to a read mode of operation and the previously recorded field is monitored. If the monitored signal is of improper amplitude or frequency, an error detector activates an alarm. The invention may also be used with non-time lapse recorders to enable the quality of a recording to be checked without requiring rewinding of tape.
    Type: Grant
    Filed: October 18, 1984
    Date of Patent: April 14, 1987
    Assignee: Odetics, Inc.
    Inventors: Robert R. Tripp, Charles H. Watts
  • Patent number: 4641202
    Abstract: A video signal reproducing apparatus having a driving mechanism for driving a magnetic tape on which a video signal is recorded as succeeding video tracks and a transducing head device for reproducing the video signal from the succeeding video tracks mounted on a cylindrical drum around which the magnetic tape is wrapped, the transducing head device having a bimorph plate and a transducing head mounted thereon is disclosed.
    Type: Grant
    Filed: September 4, 1984
    Date of Patent: February 3, 1987
    Assignee: Sony Corporation
    Inventors: Yoshiyuki Nakamura, Tetsuro Kato, Norio Ebihara
  • Patent number: 4635152
    Abstract: A magnetic playback apparatus using ferromagnetic resonance of a magnetic material provided with a magnetic anisotropy to develop an anisotropic magnetic field. The magnetic material is disposed at a position influenced by a magnetic field resulting from a signal recorded on the magnetic recording medium. The magnetic material is coupled with a high frequency circuit to be supplied with a high frequency magnetic field. The high frequency characteristics of the magnetic material greatly vary depending on a ferromagnetic resonance. A ferromagnetic resonance magnetic field is set up, allowing for the magnitude of an anisotropic magnetic field and the frequency of the high frequency magnetic field, so that a great variation in the high frequency characteristics due to the ferromagnetic resonance may be obtained according to the signal magnetic field.
    Type: Grant
    Filed: July 24, 1984
    Date of Patent: January 6, 1987
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hitoshi Iwasaki, Shu Chiba, Norikazu Sawazaki
  • Patent number: 4626910
    Abstract: In a field signal-frame signal conversion system including means for applying a delayed field signal delayed by 1/2 of one horizontal scanning period and a thru field signal, which is the same as the above field signal but not delayed, and switching means for alternately selecting the field signals at a time interval of one vertical scanning period to provide a frame signal, a circuit for preventing appearance of flicker attributable to the field signal-frame signal conversion, said circuit comprising a synchronizing signal separating circuit separating a synchronizing signal from the frame signal appearing at the output of said switching means, a sampling pulse generating circuit generating, in response to the application of the separated synchronizing signal, a sampling pulse signal synchronous with the change points from the sync tip level to the pedestal level and having a pulse width equal to or smaller than that of the serrating pulses, a sample and hold circuit operating in response to the sampling pul
    Type: Grant
    Filed: December 11, 1984
    Date of Patent: December 2, 1986
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Keiichi Kawamura
  • Patent number: 4609950
    Abstract: A magnetic recording head apparatus includes: a magnetic head body opposing a travelling magnetic tape; a tuning circuit having the head body as a variable inductance element; a high-frequency signal source for generating a high-frequency signal; and a detector connected to the tuning circuit. The inductance of the head body is changed in accordance with a change in the magnetic signal field applied from the magnetic tape. The high-frequency signal is amplitude-modulated in accordance with the high-frequency signal. A peak or envelope waveform of the modulated high-frequency signal is detected by a detector, thereby obtaining a reproduced information signal.
    Type: Grant
    Filed: March 22, 1983
    Date of Patent: September 2, 1986
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Shu Chiba, Norikazu Sawazaki
  • Patent number: 4593332
    Abstract: A capacitance element includes as an interelectrode substance a magnetic body for detecting a magnetic field formed by a magnetic recording medium. A tuned circuit includes the capacitance element as a tuning element and receives a signal from a high-frequency oscillator. The magnetic characteristics of the magnetic body change with changes in the magnetic field formed by the magnetic recording medium. The high-frequency signal output from the tuned circuit changes with changes in the magnetic characteristics of the magnetic body. A detecting circuit detects the changes in the high-frequency signal output so as to reproduce signals recorded on the magnetic recording medium.
    Type: Grant
    Filed: April 14, 1983
    Date of Patent: June 3, 1986
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Junichi Akiyama, Shu Chiba, Norikazu Sawazaki
  • Patent number: 4496995
    Abstract: In a fast frame recorder having (1) a video camera adapted to produce signals corresponding to a variety of frame rates, (2) a variable speed tape recorder adapted to down-convert the frame rate of the camera signals to a reference frame rate by appropriately reducing the recorder tape speed to a reference speed, and (3) a display monitor adapted to receive the reference frame rate signals, the camera thereof may be adjusted for various scene and frame rate conditions without need to record the camera frame rate signals (for purposes of signal down-conversion). This is, in accordance with the invention, achieved by selecting a certain line (or lines) from each frame of the camera output signal, and applying such selected lines directly to the display monitor. Skipping from line to line in the camera output signal has the effect of down-converting the frame rate of the camera output signal as required.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: January 29, 1985
    Assignee: Eastman Kodak Company
    Inventors: Joseph H. Colles, James A. Bixby
  • Patent number: 4464691
    Abstract: A magnetic head includes a magnetic body, at least the permeability or high frequency loss of which is changed with changes of the record magnetic field on a magnetic tape, and a coil. A high frequency signal is supplied to a tuned circuit, which includes the coil and a capacitor, and a signal corresponding to the record magnetic field is taken out through the detection of the changes of the voltage of the high frequency signal supplied to the tuned circuit.
    Type: Grant
    Filed: August 5, 1981
    Date of Patent: August 7, 1984
    Assignee: Tokyo Shibaura Denki Kabushiki Kaisha
    Inventors: Norikazu Sawazaki, Shu Chiba
  • Patent number: 4423450
    Abstract: An improved recording and read head particularly suited for use with perpendicular recording techniques. The recording head can be fabricated either as a single head or as a multitrack array. If fabricated as a multitrack array, the head includes a plurality of main poles spaced closely to one another and a common long flux closing pole which completes a magnetic circuit between the main poles and the recording medium. Each main pole of the head array is individually addressable with a purpose of recording or reading by means of a flux gate arrangement. The flux gate may be utilized so that the head operates either in a conventional fashion by detecting the rate of change of induced flux or by detecting the magnitude of the induced flux.
    Type: Grant
    Filed: May 6, 1981
    Date of Patent: December 27, 1983
    Assignee: Censtor Corporation
    Inventor: Harold J. Hamilton
  • Patent number: 4388657
    Abstract: In a VTR of the type having information recorded in adjacent tracks disposed angularly across the direction of tape travel, a search mode playback arrangement is incorporated having a pair of transducer gaps which are alternately enabled to continuously pickup coherent information while the playback arrangement scans across adjacent tracks during a search mode.
    Type: Grant
    Filed: November 25, 1980
    Date of Patent: June 14, 1983
    Assignee: RCA Corporation
    Inventors: Lee V. Hedlund, Donald G. Herzog, Franz L. Putzrath
  • Patent number: 4376954
    Abstract: Selected fields of a redundant field slow motion video tape reproduced video signal are stored in a memory at a given clock rate and recovered from the memory at a clock rate inversely proportional to the number of times each field is repeated so as to produce a non-redundant video output signal of reduced bandwidth yet processing the full informational content of the original video signal. The original signal normally exhibits an ordered color field sequence but is subject to anomalous variations from time to time which causes anomalous variation of the chrominance-burst phase relationship of the video output signal.
    Type: Grant
    Filed: December 11, 1980
    Date of Patent: March 15, 1983
    Assignee: RCA Corporation
    Inventor: Michael D. Ross
  • Patent number: 4309702
    Abstract: Apparatus for detecting the displacement of a member having a magnetic scale on which are provided calibrating signals of a predetermined wavelength. First and second magnetic heads are disposed to reproduce the calibrating signals from the magnetic scale; and these heads also are energized with pulse signals, whereby each of the magnetic heads produces a balanced modulated pulse signal derived from the reproduced calibrating signal and the energizing pulse signal supplied thereto. The balanced modulated pulse signals from the two heads are added to obtain a phase modulated pulse signal. A predetermined higher harmonic of the phase modulated pulse signal is selected; and predetermined increments of phase shift in the selected higher harmonic of the phase modulated pulse signal are detected so as to produce output pulse signals representing corresponding increments of displacement.
    Type: Grant
    Filed: February 23, 1979
    Date of Patent: January 5, 1982
    Assignee: Sony Corporation
    Inventors: Katsutoshi Mibu, Hikaru Kitsunezaki
  • Patent number: 4182987
    Abstract: A flux-sensitive magnetic head employs, at its back part, a structure having a thin single domain magnetic film coated thereon. A coil wraps around the coated structure, and a direct current is passed through the coil, thereby to apply a hard axis magnetic bias to the film. Signal flux appearing at the head front gap asserts a magnetic force along the hard axis of the film. Contrary to what would be expected, the signal flux causes the inductance of the coil to vary. Such inductance variation may be conveniently detected by (1) connecting the variable inductor into a tank circuit, (2) applying a high frequency ac ripple to the "hard axis" dc bias, and (3) measuring the "hard axis" detuning experienced by the tank circuit.
    Type: Grant
    Filed: August 28, 1978
    Date of Patent: January 8, 1980
    Assignee: Eastman Kodak Company
    Inventor: Charles R. Moeller
  • Patent number: 4164770
    Abstract: A flux sensitive magnetic head is disclosed wherein a thin single domain magnetic film coated on a non-conductor bridges the head gap. A magnetic bias is applied to the hard axis of the film; and flux entering the gap causes the resistivity of the film to vary about a resistance reference established by the bias. The resistance variation is converted to a useful signal corresponding to the flux entering the gap.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: August 14, 1979
    Assignee: Eastman Technology, Inc.
    Inventor: Frederick J. Jeffers
  • Patent number: 4137554
    Abstract: A flux-sensitive magnetic head employs at its back part a wire having a thin single-domain magnetic film coated thereon. A sense coil wraps around the coated wire, and, in response to current passed through the coated wire, develops a voltage proportional to the flux in the head front gap.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: January 30, 1979
    Assignee: Eastman Technology Inc.
    Inventor: Richard J. McClure
  • Patent number: 4136371
    Abstract: A flux-sensitive magnetic head employs, at its back part, a structure having a thin single domain magnetic film coated thereon. A coil wraps around the coated structure, and a direct current is passed through the coil, thereby to apply a hard axis magnetic bias to the film. Signal flux appearing at the head front gap asserts a magnetic force along the hard axis of the film. Contrary to what would be expected, the signal flux causes the inductance of the coil to vary. Such inductance variation may be conveniently detected by (1) connecting the variable inductor into a tank circuit, (2) applying a high frequency ac ripple to the "hard axis" dc bias, and (3) measuring the "hard axis" detuning experienced by the tank circuit.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: January 23, 1979
    Assignee: Eastman Technology, Inc.
    Inventor: Charles R. Moeller
  • Patent number: 4136370
    Abstract: In a magnetic head of the type having a thin film magnetically-coated electrically-conductive wire bridging the windowed back section of the head, excitation currents are applied to the wire within the windowed head section.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: January 23, 1979
    Assignee: Eastman Technology, Inc.
    Inventor: Charles R. Moeller
  • Patent number: 4123790
    Abstract: The source of anomalies in the performance characteristics of a magnetic head employing a sense wire having a thin film coated thereon and a coil coupled therewith is explained. Solution to the problem anomalies centers around use of a mandril for the coil.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: October 31, 1978
    Assignee: Eastman Technology, Inc.
    Inventors: Charles R. Moeller, Frederick J. Jeffers
  • Patent number: 4120011
    Abstract: A flux-sensitive magnetic head employs, at its back part, a structure having a thin single domain magnetic film coated thereon. A first coil wraps around the coated structure; and a second coil wraps around one pole of the head. A direct current is passed through the second coil, thereby to apply an easy axis magnetic bias to the film. By appropriately contouring the back gap of the head, signal flux appearing at the head front gap asserts a differential magnetic force to the easy axis of the film, thereby causing the inductance of the first coil to vary detectably.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: October 10, 1978
    Assignee: Eastman Kodak Company
    Inventor: Frederick John Kolb, Jr.
  • Patent number: RE31078
    Abstract: A helical scan video tape recorder suitable for slow and fast motion modes of operation is disclosed. A plurality of video fields are recorded in each video track extending across the video tape such that the burst of noise produced when the magnetic head crosses over the guard band between separate video tracks during the slow or fast mode of operation of the video recorder is encountered in only one of the field regions in the video track. This burst of noise is utilized to control the television monitor circuit so that the video field region which is free of noise is reproduced on the monitor while the video field region which contains the noise is blanked out from the monitor. As the noise progresses from one field region to the succeeding field region in the video track, means is provided for automatically switching to display of the noise-free field region.
    Type: Grant
    Filed: April 13, 1979
    Date of Patent: November 9, 1982
    Assignee: Video Logic Corporation
    Inventor: Richard J. Segerstrom