Patents Assigned to Fujitsu Media Devices Limited
  • Piezoelectric thin-film resonator and filter using the same
    Patent number: 7211931
    Abstract: A piezoelectric thin-film resonator includes a substrate, a lower electrode arranged on the substrate, a piezoelectric film arranged on the lower electrode, and an upper electrode arranged on the piezoelectric film. A region in which the upper electrode overlaps with the lower electrode through the piezoelectric film has an elliptical shape, and a condition such that 1<a/b<1.9 is satisfied where a is a main axis of the elliptical shape, and b is a sub axis thereof.
    Type: Grant
    Filed: October 18, 2004
    Date of Patent: May 1, 2007
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Tokihiro Nishihara, Tsuyoshi Yokoyama, Takeshi Sakashita, Masafumi Iwaki, Tsutomu Miyashita
  • Bonded substrate, surface acoustic wave chip, and surface acoustic wave device
    Patent number: 7208859
    Abstract: A bonded substrate includes a lithium tantalate substrate and a sapphire substrate to which the lithium tantalate substrate is bonded, a bonded interface of the lithium tantalate and the sapphire substrate includes a bonded region in an amorphous state having a thickness of 0.3 nm to 2.5 nm. The bonded region in the amorphous state is formed by activating at least one of the lithium tantalate substrate and the sapphire substrate in the bonded interface with neutralized atom beams, ion beams or plasma of inert gas or oxygen. It is possible to bond the piezoelectric substrate to the supporting substrate having different lattice constants without the high-temperature thermal treatment and realize the bonded substrate having an excellent bonding strength and being less warped.
    Type: Grant
    Filed: March 2, 2005
    Date of Patent: April 24, 2007
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Michio Miura, Masanori Ueda, Shunichi Aikawa, Toru Uemura, Kunihisa Wada, Naoyuki Mishima
  • Method of packaging electronic parts
    Patent number: 7200924
    Abstract: A method of fabricating electronic parts includes the steps of: mounting electronic elements in regular cavities that are two-dimensionally arranged on a baseboard on which dummy cavities are provided so as to surround the regular cavities, and covering a top of the baseboard with a resin sheet.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: April 10, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventor: Shingo Masuko
  • Surface acoustic wave device and method of manufacturing the same
    Patent number: 7202590
    Abstract: A surface acoustic wave device includes: a piezoelectric substrate that has two or more resonators formed on a surface; and a supporting substrate that is joined to another surface of the piezoelectric substrate. In this surface acoustic wave device, at least two of the resonators have exciting portions that overlap each other in the direction of propagating surface acoustic waves, and at least a part of the piezoelectric substrate is removed or modified to have different properties between at least one pair of overlapping resonators among the resonators having the overlapping portions.
    Type: Grant
    Filed: May 7, 2004
    Date of Patent: April 10, 2007
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Takashi Matsuda, Michio Miura, Yoshio Satoh, Masanori Ueda
  • Elastic wave apparatus
    Patent number: 7190241
    Abstract: A surface acoustic wave apparatus is configured to avoid destruction from static electricity. The surface acoustic wave apparatus includes a piezoelectric substrate; a surface acoustic wave element having at least one interdigital electrode made up of a conductive film on the piezoelectric substrate; and a thin film electrically connected between terminals connecting to electrode fingers of the interdigital electrode, the thin film showing varistor characteristics formed on the piezoelectric substrate.
    Type: Grant
    Filed: May 27, 2005
    Date of Patent: March 13, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventors: Yasuo Ebata, Osamu Kawachi
  • Angular velocity sensor
    Patent number: 7188525
    Abstract: An angular velocity sensor is provided that includes a frame, an oscillator and torsion bars that connect the oscillator to the frame. The frame, the oscillator and the torsion bar are formed integral with each other by etching a material substrate in the thickness direction of the substrate. The oscillator, configured in the form of an H, includes a support, two first arms and two second arms. These arms extend from the support in an arm-extending direction perpendicular to the thickness direction of the substrate. The oscillator includes a mounting surface that is provided with a piezoelectric driver for generating in-plane oscillation of the oscillator, and with a piezoelectric detector for detecting out-of-plane oscillation of the oscillator.
    Type: Grant
    Filed: April 22, 2002
    Date of Patent: March 13, 2007
    Assignees: Fujitsu Limited, Fujitsu Media Devices Limited
    Inventors: Atsushi Machida, Suguru Warashina, Hiroshi Ishikawa, Tsutomu Miyashita, Yoshio Satoh
  • Surface acoustic wave device, package for the device, and method of fabricating the device
    Patent number: 7180228
    Abstract: A surface acoustic wave device includes a surface acoustic wave chip having a piezoelectric substrate on which comb-like electrodes and electrode pads are formed, and a package housing the surface acoustic wave chip, a first surface of the package including an opening of the cavity being wider than a second surface of the package opposite to the first surface.
    Type: Grant
    Filed: June 15, 2004
    Date of Patent: February 20, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventors: Shingo Masuko, Naoyuki Mishima, Masao Irikura
  • Surface acoustic wave device
    Patent number: 7180388
    Abstract: The present invention provides a surface acoustic wave device that allows a plurality of surface acoustic wave filters to be formed on a single chip and permits greater miniaturization. The surface acoustic wave device comprises a piezoelectric substrate, a first surface acoustic wave resonator formed on the piezoelectric substrate, and a second surface acoustic wave resonator formed on the piezoelectric substrate in the surface acoustic wave propagation direction of the first surface acoustic wave resonator. The positions in which the first and second surface acoustic wave resonators are formed on the piezoelectric substrate are in an at least partially overlapping relationship in a surface acoustic wave propagation region that is defined by virtually extending the respective openings of the first and second surface acoustic wave resonators.
    Type: Grant
    Filed: January 6, 2005
    Date of Patent: February 20, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventors: Satoru Matsuda, Osamu Kawachi
  • Surface acoustic wave device and method of producing the same
    Patent number: 7176599
    Abstract: A surface acoustic wave device includes: interdigital transducers; first electrode pads that are connected to the interdigital transducers through wire patterns; and a piezoelectric substrate on which the interdigital transducers, the first electrode pads, and the wire patterns, are formed. In this surface acoustic wave device, at least one of the first electrode pads is not connected to a ground pattern, and the piezoelectric substrate has a conductivity in the range of 10?12/?·cm to 10?6/?·cm.
    Type: Grant
    Filed: June 4, 2004
    Date of Patent: February 13, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventors: Osamu Kawachi, Yoshiro Fujiwara
  • Surface acoustic wave device with a thicker partial bus bar area and optimal bus bar to electrode tip gap
    Patent number: 7170371
    Abstract: Efficient transverse energy confinement, and provision of a surface acoustic wave filter having preferable characteristics of both insertion loss and shape factor are obtained. In the surface acoustic wave filter, electrode fingers of one comb electrode are laid in a state of being inserted to the electrode fingers of the other comb electrode, and a thick film thicker than each plurality of electrode fingers is produced in a partial area of the bus bar, and a tip gap is provided between the top of each plurality of electrode fingers and the end face of the opposed bus bar, with a distance therebetween set not greater than 0.2? (where, ? is one period of the comb electrode).
    Type: Grant
    Filed: April 14, 2004
    Date of Patent: January 30, 2007
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Masanori Ueda, Osamu Kawachi, Shogo Inoue, Jun Tsutsumi, Takashi Matsuda, Yoshio Satoh
  • Surface acoustic wave device having reflectors with both open and shorted electrodes
    Patent number: 7157991
    Abstract: A surface acoustic wave device for implementing an attenuation characteristic outside of the pass band and the narrow band characteristics, preferably for use as a filter. The surface acoustic wave device includes a piezoelectric substrate, interdigital transducers formed on the piezoelectric substrate, and first and second reflectors disposed on the sides of the interdigital transducers. Each of the first and second reflectors includes an open electrode block with a plurality of electrically independent electrode fingers, and a short electrode block with a plurality of electrode fingers of which both ends are electrically shorted.
    Type: Grant
    Filed: December 29, 2003
    Date of Patent: January 2, 2007
    Assignee: Fujitsu Media Devices Limited
    Inventors: Osamu Kawachi, Takuya Abe, Yasufumi Kaneda, Motoyuki Tajima
  • Surface acoustic wave filter and duplexer including the same
    Patent number: 7154359
    Abstract: A surface acoustic wave filter includes: an input interdigital transducer and an output interdigital transducer that are formed on a piezoelectric substrate; a capacitance that is provided between the input terminal of the input interdigital transducer and the output terminal of the output interdigital transducer; a first common ground terminal that connects the ground terminal of the input interdigital transducer and the ground terminal of the output interdigital transducer; and an inductance that is provided between the first common ground terminal and a ground.
    Type: Grant
    Filed: May 20, 2004
    Date of Patent: December 26, 2006
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Shogo Inoue, Jun Tsutsumi, Takashi Matsuda, Masanori Ueda
  • Filter using piezoelectric material
    Patent number: 7154360
    Abstract: A filter includes a piezoelectric substrate, and interdigital transducers (IDTs) that are formed on the piezoelectric substrate. At least one of the IDTs has a main electrode finger pattern that is weighted. The IDT having the main electrode finger pattern also has a sub electrode finger pattern that is connected in parallel to the main electrode finger pattern, and generates a surface acoustic wave that cancels a surface acoustic wave caused by leakage electric fields generated in the main electrode finger pattern.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: December 26, 2006
    Assignee: Fujitsu Media Devices Limited
    Inventors: Koichi Wada, Satoshi Ichikawa, Hirotada Wachi, Tohru Takezaki, Tsuyoshi Oura, Toshifumi Tanaka, Satoshi Orito
  • Filter chip and filter device
    Patent number: 7145417
    Abstract: A filter chip includes multiple series-arm resonators arranged in series arms of a ladder arrangement, and multiple parallel-arm resonators arranged in parallel arms of the ladder arrangement. A common line is connected to first electrodes of at least two parallel-arm resonators among the multiple parallel-arm resonators. Second electrodes of said at least two parallel-arm resonators are connected to associated series-arm resonators among the multiple series-arm resonators.
    Type: Grant
    Filed: March 27, 2003
    Date of Patent: December 5, 2006
    Assignees: Fujitsu Limited, Fujitsu Media Devices Limited
    Inventors: Rei Kimachi, Tokihiro Nishihara, Takeshi Sakashita, Tsuyoshi Yokoyama, Tsutomu Miyashita
  • Branching filter having both saw ladder and dual mode filters, and electronic apparatus using the branching filter
    Patent number: 7135944
    Abstract: A duplexer includes two surface acoustic wave filter having different band center frequencies, and a phase matching circuit that matches the phases of the two surface acoustic wave filters to each other. In this duplexer, one of the two surface acoustic wave filters is a ladder type surface acoustic wave filter, while the other one of the two surface acoustic wave filters includes two or more dual-mode type surface acoustic wave filters that are connected in parallel.
    Type: Grant
    Filed: October 17, 2002
    Date of Patent: November 14, 2006
    Assignees: Fujitsu Media Devices Limited, Fujitsu Limited
    Inventors: Yasuhide Iwamoto, Shogo Inoue, Osamu Ikata, Jun Tsutsumi
  • Surface acoustic wave device
    Patent number: 7102462
    Abstract: The present invention permits further miniaturization and shortening of a surface acoustic wave device while avoiding the influence of the surface acoustic wave device on the inductance value and performance index (Q value) of the spiral inductor. The chip on which the spiral inductor is formed is flip-chip mounted in a package together with another surface acoustic wave device chip. The package is provided with a hermetically sealed lid. A conductor pattern is formed on a face of the package that opposes the spiral inductor. Further, the overlap between the region of the spiral inductor and the conductor pattern is 7% or less.
    Type: Grant
    Filed: December 30, 2004
    Date of Patent: September 5, 2006
    Assignee: Fujitsu Media Devices Limited
    Inventors: Noriaki Taniguchi, Osamu Furukawa, Toshihiko Murata, Osamu Kawachi
  • Angular velocity sensor
    Patent number: 7096733
    Abstract: An angular velocity sensor includes a stem and a vibrator that is supported by the stem. The vibrator is inclined to a mounting surface of the stem. The angle of inclination of the vibrator to the mounting surface is adjustable. For this reason, the angular velocity sensor also includes a holding member that holds the vibrator. This holding member is elastically deformable. A single material may be folded to shape the holding member.
    Type: Grant
    Filed: November 29, 2004
    Date of Patent: August 29, 2006
    Assignee: Fujitsu Media Devices Limited
    Inventors: Kazuhiro Ohta, Masanori Yachi, Katsuhiko Takahashi
  • Micromirror unit and method of making the same
    Patent number: 7099066
    Abstract: A method is provided for making a micromirror unit which includes a frame, a mirror forming base, and bridges connecting the frame to the mirror forming base. The method includes the following steps. First, a first mask pattern is formed on a substrate for masking portions of the substrate which are processed into the frame and the mirror forming base. Then, a second mask pattern is formed on the substrate for masking portions of the substrate which are processed into the bridges. Then, the substrate is subjected to a first etching process with the first and the second mask patterns present as masking means. Then, the second mask pattern is removed selectively. Then, the substrate is subjected to a second etching process with the first mask pattern present as masking means. Finally, the first mask pattern is removed.
    Type: Grant
    Filed: March 18, 2005
    Date of Patent: August 29, 2006
    Assignees: Fujitsu Limited, Fujitsu Media Devices Limited
    Inventors: Osamu Tsuboi, Satoshi Ueda, Yoshihiro Mizuno, Ippei Sawaki, Fumio Yamagishi
  • PLL circuit, communication apparatus equipped with PLL circuit, and frequency adjustment method
    Patent number: 7095286
    Abstract: A PLL circuit includes a voltage-controlled oscillator having a control voltage terminal, a charge pump, a loop filter having an output coupled with the control voltage terminal via the loop filter, and a part for connecting any point on a route from an output terminal of the charge pump to the control voltage terminal to ground and disconnecting said point from the ground after a frequency of the voltage-controlled oscillator is adjusted.
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: August 22, 2006
    Assignee: Fujitsu Media Devices Limited
    Inventor: Yasushi Fukuda
  • Acceleration sensor
    Patent number: 7093489
    Abstract: A piezoelectric vibrator 2 that generates an electric charge according to a stress and a weight 1 provided on the piezoelectric vibrator 2 are included. The piezoelectric vibrator 2 has multiple pairs of sensing electrodes 3a and 3b, and 4a and 4b, and the sensing electrodes 3a and 3b, and 4a and 4b are respectively connected in parallel so that capacitances Cd1 and Cd2 made of the sensing electrodes may be connected in parallel. It is thus possible to double the charge sensitivity with keeping the voltage sensitivity.
    Type: Grant
    Filed: February 14, 2005
    Date of Patent: August 22, 2006
    Assignee: Fujitsu Media Devices Limited
    Inventors: Hiroshi Tanaka, Masanori Yachi