Patents by Inventor Kenzaburou Iijima

Kenzaburou Iijima 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: 4879674
    Abstract: For reliable and stable detection of the movement of a mobile body, a pair of filters for performing specified and different calculations are interposed between an analog-digital (A/D) converter and a digital phase locked circuit. The calculations carried out by the filters are selectively utilized either alone or in combination to minimize noise present after A/D conversion.
    Type: Grant
    Filed: January 14, 1988
    Date of Patent: November 7, 1989
    Assignee: Yamaha Corporation
    Inventors: Kenzaburou Iijima, Yoshinori Hayashi
  • Patent number: 4855740
    Abstract: In construction of a keyboard for word processors and computer machines, character patterns of different key arrangement modes are stored in different memories for selective read-out so that any key arrangement mode chosen by an operator should be visually indicated on keys, thereby enabling use of a keyboard in various modes.
    Type: Grant
    Filed: September 25, 1987
    Date of Patent: August 8, 1989
    Assignee: Yamaha Corporation
    Inventors: Toshihiro Muramatsu, Kenzaburou Iijima, Yoshinori Hayashi
  • Patent number: 4851752
    Abstract: In construction of a peripheral-magnetization type magnetic encoder having a rotary spindle and a magnetic head, a resin housing is formed by insert moulding so as to embrace the spindle leaving a slight tubular clearance to allow free axial rotation of the spindle, thereby providing direct, simple and stable support to the rotary spindle for enhanced precision in direction.
    Type: Grant
    Filed: March 15, 1988
    Date of Patent: July 25, 1989
    Assignee: Yamaha Corporation
    Inventors: Seiya Nishimura, Mitsuo Yamaguchi, Kenzaburou Iijima
  • Patent number: 4847879
    Abstract: In construction of a digital phase locked loop for detection of the angular displacement of a mobile object depending on input signals from an encoder, is provided a bit number control circuit so that working bit numbers of A/D converters and a counter in the loop are automatically reduced as the frequency of the input signals rise and, in accordance with such reduction in working bit number, a function generating ROM of a smaller bit number is selected from a group of function generating ROMs of different bit numbers for supply of address data to multipliers connected to the A/D converters, thereby the signal processing speed of the loop is significantly raised to face up to current speed-up in the mobile object displacement.
    Type: Grant
    Filed: March 2, 1988
    Date of Patent: July 11, 1989
    Assignee: Yamaha Corporation
    Inventors: Kenzaburou Iijima, Yoshinori Hayashi, Makoto Suzuki, Atsushi Uchiyama
  • Patent number: 4811254
    Abstract: An absolute displacement detector utilizing two sensors and a code bearing track having domains arranged such that relative movement between the sensors and the track produces two signals in phase quadrature which are processed with digital circuitry to provide displacement data indicated by a multiple bit digital word whose higher bits indicate number of domains passed and whose lower bits indicate position within a domain.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: March 7, 1989
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventors: Kenzaburou Iijima, Yuoshinori Hayashi, Terumoto Nonaka, Akira Usui
  • Patent number: 4806860
    Abstract: A magnetoresistive detection head for detecting relative displacement of a magnetic recording medium relative to the detection head includes two sets of magnetoresistive elements which change their respective resistances in response to changes in the intensity of a magnetic field generated by the magnetic recording medium during the relative displacement. The magnetoresistive elements are overlapped and spaced relative to each other by a specified space lag in the direction of the relative displacement. One set of magnetoresistive elements produce a sine output and the other a cosine output. The overlapping and precise spacing of the elements aligns the phases of the signal envelopes of the sine and cosine outputs, reducing reading errors when physical warps appear on the magnetic recording medium.
    Type: Grant
    Filed: June 9, 1987
    Date of Patent: February 21, 1989
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventors: Kenzaburou Iijima, Yoshinori Hayashi, Terumoto Nonaka, Katsuyuki Yokoi, Seiya Nishimura
  • Patent number: 4782329
    Abstract: In construction of a displacement detector for an encoder provided with a phase locked loop connected to a detection head facing a scale of the encoder, use of a signal switching circuit allows optimum selection of signals used for generation of a system output signal depending on the speed of the relative movement between the detection head and the scale, thereby assuring generation of the system output signal at high degree of dissolution at any speed of the relative movement. Further, additional use of a parallel/serial converting unit assures high reliability in transmission of the system output signal to external systems.
    Type: Grant
    Filed: April 30, 1987
    Date of Patent: November 1, 1988
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventors: Kenzaburou Iijima, Yoshinori Hayashi
  • Patent number: 4768119
    Abstract: A non-contact detection head which compensates for variation and the spacing between a detection head and a circular recording medium. The recording medium has a magnetized pattern recorded along the periphery thereof, and is mounted on a central rotary shaft. A detection head is spaced from and faces the recorded pattern on the recording medium and generates an output as a function of the recorded pattern. In one embodiment, pneumatic means is provided for preventing fluctuations in the clearance between the recording medium and the detection head from influencing the output of the detection head. In a second embodiment, a mechanical arrangement is provided to achieve this result. In a third embodiment, an electrical circuit is provided to compensate for fluctuations in the clearance between the recording medium and the detection head.
    Type: Grant
    Filed: March 3, 1987
    Date of Patent: August 30, 1988
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventors: Kenzaburou Iijima, Kazuo Kurahashi, Yoshinori Hayashi
  • Patent number: 4683013
    Abstract: In production of a shadow mask for a color cathode ray tube from spinodal decomposition type magnet alloys, application of two staged agings before shaping successfully avoids thermal deformation of the product.
    Type: Grant
    Filed: November 12, 1985
    Date of Patent: July 28, 1987
    Assignee: Nippon Gakki Seizo Kabushiki Kaisha
    Inventors: Kenzaburou Iijima, Yoshinori Hayashi