Patents by Inventor Kazuhiro Momata

Kazuhiro Momata has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5181149
    Abstract: A magnetic recording/reproducing head assembly comprising a first magnetic path forming member on which a coil is mounted, a second magnetic path forming member which forms a magnetic path in cooperation with the first magnetic path forming member, and a film laminate formed at a front gap portion between the first magnetic path forming member and the second magnetic path forming member. The film laminate includes a magnetic detecting element for detecting a change in a magnetic field and a soft magnetic film or films. This magnetic head assembly is prepared by forming the film laminate on a head base of the head assembly, bonding a core member to the head base with the film laminate formed thereon, and mounting a coil on the core member.
    Type: Grant
    Filed: September 18, 1989
    Date of Patent: January 19, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Masao Katsumata, Kazuhiro Momata, Kazuyoshi Adachi, Tooru Takeura, Masahiro Kitada, Yoshihisa Kamo, Toshikane Yoshimatsu
  • Patent number: 5032943
    Abstract: A magnetoresistive head including a magnetoresistive element in which the magnetoresistive head has a specifically determined gap length and/or the magnetoresistive element has a specifically determined magnetostriction constant to thereby define a reproduction output vs. operation current characteristic curve of the head. The above-mentioned gap length and/or magnetostriction constant is determined such that a saturation operation current for which a reproduction output of the head is maximum is higher than an operation current with which the head is operative.
    Type: Grant
    Filed: February 23, 1989
    Date of Patent: July 16, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Masao Katsumata, Kazuhiro Momata, Kazuyoshi Adachi, Kousaku Chida
  • Patent number: 4860140
    Abstract: The magnetic head according to the present invention has a ferrite substrate and closure. The ferrite substrate has formed therein a first recess in which a conductive coil is to be deposited, while the ferrite closure has formed therein a second recess enclosing a portion of the conductive coil that is contributed to at least signal transducing. The end of the second recess is disposed in a position related with the depth of the tranducing gap. Since the first recess in which the conductive coil is deposited has no influence on the magnetic transducing efficiency, it can be much freely formed by photolithography or reactive ion etching. Also since the second recess having an influence on the magnetic transducing efficiency can be formed by precision machining, no advanced process control is needed.
    Type: Grant
    Filed: April 7, 1988
    Date of Patent: August 22, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiro Momata, Kousaku Chida, Tooru Takeura, Yukihisa Tsukada
  • Patent number: 4843486
    Abstract: A method of fabricating a multi-element magnetic head core is provided in which a plurality of first grooves are formed in a surface of a magnetic block to form a plurality of magnetic circuits, a plurality of second grooves are formed in this surface in directions perpendicular to the first grooves to separate the magnetic circuits from each other, the first and second grooves are filled with a non-magnetic material, the magnetic block is then cut along lines parallel to the second grooves to obtain a plurality of core blocks, and a third groove is formed in each core block from a side wall thereof to isolate the magnetic circuits completely from each other. According to this method, the number of fabrication steps required for forming a multi-element magnetic head core can be reduced, and moreover a multiplicity of magnetic head cores can be formed at the same time.
    Type: Grant
    Filed: April 3, 1987
    Date of Patent: June 27, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Toshikane Yoshimatsu, Yoshiki Hagiwara, Yoshikazu Tsuji, Kazuhiro Momata
  • Patent number: 4841399
    Abstract: The use of a pure zirconium film as a shunt film in a magnetoresistive head having a permalloy film as a magnetoresistive film and a shunt film for application of a transverse biasing magnetic field serves to improve the heat resistance of the magnetoresistive element and allows an increase in the temperature used in the process for producing a magnetic head.
    Type: Grant
    Filed: December 1, 1986
    Date of Patent: June 20, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Kitada, Noboru Shimizu, Hideo Tanabe, Hitoshi Nakamura, Tetsuo Kobayashi, Tooru Takeura, Kazuhiro Momata
  • Patent number: 4821012
    Abstract: A shunt biased magnetoresistive element includes a sensor part sensitive to an external magnetic field and a pair of leads (electrodes) in contact with the sensor part. The width (W) of the contact between the sensor part and each of the leads is selected to be equal to or larger than the width (L) of the sensor part. The MR element further includes a center tap having a width (W') selected to be two or more times as large as the width (L) of the sensor part, because the quantity of current flowing through the center tap is two times as large as that flowing through each of the end leads.
    Type: Grant
    Filed: July 14, 1987
    Date of Patent: April 11, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yoshihisa Kamo, Kazuhiro Momata
  • Patent number: 4807073
    Abstract: A magnetoresistance type magnetic head, in which a magnetoresistance film is disposed through an insulating film between two soft magnetic bodies, and a signal leadout conductor for the magnetoresistance film is disposed in the insulating film so that its surface is at the same level as that of the insulating film, thereby providing a high-performance magnetoresistance type magnetic head, in which the gap length is small and the resistance of the signal leadout conductor portion is small.
    Type: Grant
    Filed: April 20, 1987
    Date of Patent: February 21, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tooru Takeura, Kazuhiro Momata
  • Patent number: 4802043
    Abstract: The present invention relates to the structure of a magneto-resistive head for reducing the spike noises generated in the head and for increasing the signal to noise ratio when the information is reproduced. In order to achieve the object, an electric conductor layer is disposed at both sides or one side of a magneto-resistive element, and the conductor layer is isolated from the element and connected to a DC potential.
    Type: Grant
    Filed: February 11, 1986
    Date of Patent: January 31, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Naoki Sato, Yoshihisa Kamo, Tooru Takeura, Masao Katsumata, Kazuhiro Momata
  • Patent number: 4796132
    Abstract: Conductor film terminals of a thin film magnetic head are composed of an Au film while lead terminals of a flexible printed circuit board are covered with an Au layer, so that both of these terminals can be bonded by low temperature ultrasonic bonding directly between Au and Au. The reverse surface of the lead terminals of the flexible printed circuit board is bonded and fixed to a flexible polymer resin cover film so that the dimensional accuracy of the bonded terminal portion can be improved.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: January 3, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Yoshinori Dekura, Kazuhiro Momata, Tokiyuki Seto
  • Patent number: 4783711
    Abstract: In a magnetoresistive sensor having a magnetoresistive effect element which is held between two sheets of high permeability magnetic ferrite with insulating layers interposed between them, a ferromagnetic metal film is provided adherently to the high permeability magnetic ferrite between the ferrite and the insulating layer, a rise in temperature of the magnetoresistive effect element thereby being held down and a reproduced waveform being made sharp, and thus the characteristics of the element being improved with the life thereof prolonged.
    Type: Grant
    Filed: June 27, 1986
    Date of Patent: November 8, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Kitada, Hideo Tanabe, Noboru Shimizu, Hitoshi Nakamura, Kazuhiro Momata, Shigeyoshi Kato, Tooru Takeura, Tetsuo Kobayashi
  • Patent number: 4695909
    Abstract: A magnetic head for recording and reproducing information on and from a flexible magnetic recording tape. The active face of tape supporting protrusions formed in the magnetic head is so configured that the contacting area between the supporting protrusion and the recording tape is smaller at both end portions of the protrusion than an intermediate portion thereof as viewed in the direction widthwise of the recording tape, whereby improved contacting state and floating state between the magnetic head and the recording tape can be assured over the whole width of the flexible recording tape.
    Type: Grant
    Filed: November 8, 1984
    Date of Patent: September 22, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiro Momata, Yoshinori Dekura, Tadashi Honzawa, Hiromi Matsushige
  • Patent number: 4600965
    Abstract: In a current driving circuit which supplies a two-terminal load with current to be inverted in accordance with input information, a current driving circuit according to the present invention comprises a load whose one-side terminal has its potential fixed, circuitry to supply a non-fixed side terminal of the load with a direct current, and circuitry to supply the non-fixed side terminal with a current having a magnitude double that of the direct current and a polarity opposite to that of the direct current, while switching it in accordance with input information. Owing to such construction, the number of terminals to be led out from the loads can be reduced, and a load current can be inverted at high speed. In addition, reliability can be enhanced because the assembling process is simplified.
    Type: Grant
    Filed: February 16, 1984
    Date of Patent: July 15, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Naoki Sato, Yoshihisa Kamo, Yasuhiro Katoh, Kazuhiro Momata, Shinichi Arai