Patents by Inventor Toyoji Tabuchi

Toyoji Tabuchi 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: 5438305
    Abstract: A high frequency module is disclosed which comprises a high frequency device in a package, a circuit formed on a flexible substrate in the package, the circuit, the high frequency device and input/output terminals of the package being connected electrically.
    Type: Grant
    Filed: August 3, 1992
    Date of Patent: August 1, 1995
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha, Hitachi Video & Information System, Inc.
    Inventors: Mitsutaka Hikita, Atsushi Sumioka, Takatoshi Akagi, Toyoji Tabuchi, Nobuhiko Shibagaki
  • Patent number: 5422615
    Abstract: In a high frequency circuit device, inductive circuit elements constituting a matching circuit are constructed of so-called helical coils having fine metal wires wound in a hollow solenoid form, which are disposed inside a package in which a high frequency circuit element such as a surface acoustic wave element or the like is mounted. The high frequency circuit device may be utilized in equipment such as wireless communication equipment for reducing the size as well as providing good high frequency characteristics.
    Type: Grant
    Filed: September 14, 1993
    Date of Patent: June 6, 1995
    Assignees: Hitachi, Ltd., Hitachi Video & Information System, Inc.
    Inventors: Nobuhiko Shibagaki, Mitsutaka Hikita, Toyoji Tabuchi, Takatoshi Akagi, Satoshi Wakamori, Tomomi Matsumoto
  • Patent number: 5235234
    Abstract: A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the propagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
    Type: Grant
    Filed: October 31, 1991
    Date of Patent: August 10, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Mitsutaka Hikita, Toyoji Tabuchi, Nobuhiko Shibagaki, Atsushi Isobe, Kazuhito Kurosawa
  • Patent number: 5202652
    Abstract: A surface acoustic wave device is disclosed for use in a communication apparatus where the surface acoustic wave device has a multiple of surface acoustic wave elements with different filter characteristics formed on mutually distinct piezoelectric substrates. The different filter characteristics combine to form filters having desired filter characteristics.
    Type: Grant
    Filed: October 10, 1990
    Date of Patent: April 13, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Toyoji Tabuchi, Mitsutaka Hikita, Nobuhiko Shibagaki, Tetsuya Hirashima
  • Patent number: 5115216
    Abstract: Disclosed is a SAW filter employing a SAW resonator which is constructed of a plurality of pairs of electrode fingers formed on a piezoelectric substrate, and in which a plurality of SAW transmission spaces are included. The SAW transmission spaces do not have the function of exciting a SAW, and they have electric lengths which match the phases of SAWs excited by the resonator. In accordance with frequency characteristics required of the filter, such SAW transmission spaces are introduced into, for example, one of a plurality of SAW resonators located on the electric power input side of the filter.
    Type: Grant
    Filed: April 7, 1989
    Date of Patent: May 19, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Mitsutaka Hikita, Toyoji Tabuchi, Kazuhito Kurosawa, Nobuhiko Shibagaki
  • Patent number: 5087901
    Abstract: At least one electro-acoustic transducer of a first surface acoustic wave device and acousto-electric transducers of a second surface acoustic wave device are arranged symmetrically to the first surface acoustic wave device about a line parallel to a propagating direction of surface acoustic wave and is phase-weighted differently from the remaining transducers having common phase-weighting, to improve an attenuation for stop frequency.
    Type: Grant
    Filed: March 8, 1990
    Date of Patent: February 11, 1992
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhito Kurosawa, Mitsutaka Hikita, Toyoji Tabuchi, Nobuhiko Shibagaki, Tetsuya Hirashima
  • Patent number: 5065065
    Abstract: A surface acoustic wave device comprises a piezoelectric substrate and a plurality of electrode fingers which are located on the piezoelectric substrate along the progagation direction of a surface acoustic wave. The electrode fingers are located on the piezoelectric substrate at a pitch of about 1.5.lambda.o/2 (where a symbol .lambda.o indicates a wavelength of a surface acoustic wave with a frequency equivalent to the center frequency of the surface acoustic wave device). The width of each of the electrode fingers is about 1.5.lambda.o/4. The electrode fingers are located on the substrate so as to be electrically independent of an external circuit and each other.Since the width of electrode fingers is about 1.5.lambda.o/4, the surface acoustic wave device can be produced without fine processing techniques.
    Type: Grant
    Filed: May 21, 1990
    Date of Patent: November 12, 1991
    Assignee: Hitachi, Ltd.
    Inventors: Mitsutaka Hikita, Toyoji Tabuchi, Nobuhiko Shibagaki, Atsushi Isobe, Kazuhito Kurosawa
  • Patent number: 5010269
    Abstract: A SAW resonator includes resonating SAW transducer units formed on a piezoelectric substrate and juxtaposed in a direction of propagation of acoustic waves, and a unidirectionally reflecting SAW transducer unit provided in each end of the juxtaposed resonating SAW transducer units on the substrate. Each resonating SAW transducer unit includes first and second SAW transducers connected in series and/or in parallel with each other.
    Type: Grant
    Filed: December 9, 1988
    Date of Patent: April 23, 1991
    Assignees: Hitachi, Ltd., Hitachi Denshi Kabushiki Kaisha, Hitachi Communication System, Inc.
    Inventors: Mitsutaka Hikita, Atsushi Sumioka, Toyoji Tabuchi, Kazuhito Kurosawa, Tuneo Kinoshita
  • Patent number: 4906885
    Abstract: A surface acoustic wave device has its inter--digital transducers made of a 3--metal alloyed material consisting of aluminum, copper and magnesium.
    Type: Grant
    Filed: September 21, 1988
    Date of Patent: March 6, 1990
    Assignees: Hitachi Denshi Kabushiki Kaisha, Hitachi, Ltd.
    Inventors: Hiroomi Kojima, Toyoji Tabuchi, Mitsutaka Hikita, Kazuhito Kurosawa, Atsushi Sumioka
  • Patent number: 4507581
    Abstract: At least two frequencies, one on the higher frequency side and the other on the lower frequency side of a desired frequency, are selected from a predetermined set of frequencies, and stripe widths corresponding to the selected frequencies are combined to realize a desired average stripe width which is used to form an electrode structure of a SAW device. At least one electrode configuration of the SAW device includes an alternate arrangement of electrode stripe and free area stripe and the alternate arrangement is divided into a predetermined number of plural sections within each of which a ratio of the number of stripes of a first width to the number of stripes of a second width is set to a predetermined value. The electrode configuration can be prepared without resort to a highly precise mask and can permit highly precise setting of the center frequencies.
    Type: Grant
    Filed: September 28, 1983
    Date of Patent: March 26, 1985
    Assignee: Hitachi, Ltd.
    Inventors: Toyoji Tabuchi, Mitsutaka Hikita
  • Patent number: 4255726
    Abstract: A surface acoustic wave filter having transmitting and receiving transducers, coupling transducers, as well as reflecting transducers which are arrayed on a piezo-electric substrate. The coupling transducers are so designed as to function as 3-dB directional couplers in order to obtain frequency characteristics over a wide range without developing ripples.
    Type: Grant
    Filed: March 7, 1979
    Date of Patent: March 10, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Yasuaki Kinoshita, Toyoji Tabuchi
  • Patent number: 4021798
    Abstract: A liquid crystal display panel is composed of a plate of ferroelectric material, a group of electrodes arranged in a first direction on one surface of the plate, a second group of electrodes arranged in a second direction orthogonal to the first direction on a second surface of the plate, dielectric films disposed on the first group of electrodes, intermediate electrodes the main part of which is situated on each of the dielectric films and the side part of which is situated on a second surface of the plate opposite each of the second group of electrodes. A transparent substrate is arranged opposite the second surface of the plate, a third group of electrodes are arranged on the transparent substrate opposite and parallel to each of the second group of electrodes and means is provided for connecting each of the second group of electrodes to each of the third group of electrodes which is opposite to the former, and a liquid crystal is interposed between the transparent substrate and the plate.
    Type: Grant
    Filed: October 14, 1975
    Date of Patent: May 3, 1977
    Assignee: Hitachi, Ltd.
    Inventors: Hiroomi Kojima, Hideo Zama, Sadao Nomura, Toyoji Tabuchi, Ryozo Murata