Patents by Inventor Kunihito Yamanaka

Kunihito Yamanaka 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: 8723393
    Abstract: A SAW device 11 has an IDT which is provided on the principal surface of a quartz crystal substrate 12 having Euler angles (?1.5°???1.5°, 117°???142°, 42.79°?|?|?49.57°) and excites a SAW in a stopband upper end mode, and a pair of reflectors which are arranged on both sides of the IDT. Inter-electrode-finger grooves are recessed between the electrode fingers of the IDT, and inter-conductor-strip grooves are recessed between the conductor strips of the reflectors. The wavelength ? of the SAW and the depth G of the inter-electrode-finger grooves satisfy 0.01??G. An IDT line occupancy ? and the depth G of the inter-electrode-finger grooves satisfy a predetermined relational expression. The IDT line occupancy ? and a reflector line occupancy ?r satisfy the relationship ?<?r. Therefore, an excellent frequency-temperature characteristic and a high Q value in an operation temperature range are realized simultaneously.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: May 13, 2014
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8723396
    Abstract: A SAW device has an IDT which is provided on the principal surface of a quartz crystal sustrate having Euler angles (?1.5°???1.5°, 117°???142°, ?) and excites a SAW in a stopband upper end mode. Inter-electrode-finger grooves 8 are recessed between the electrode fingers of the IDT. When the Euler angle ? is 42.79°?|?|?49.57°, the thickness H of the electrode fingers of the IDT is set to be within 0.055 ?m?H?0.335 ?m, preferably, 0.080 ?m?H?0.335 ?m. When the Euler angle ? is |?|?90°×n (where n=0, 1, 2, 3), and the thickness H of the electrode fingers is set to 0.05 ?m?H?0.20 ?m.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: May 13, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Kunihito Yamanaka, Takuya Owaki, Naohisa Obata
  • Patent number: 8723394
    Abstract: A SAW device has an IDT which is provided in the principal surface of a quartz crystal substrate having Euler angles (?1.5°???1.5°, 117°???142°, |?|?90°×n (where n=0, 1, 2, 3)) and excites a Rayleigh wave (wavelength: ?) in a stopband upper end mode. Inter-electrode-finger grooves are recessed between the electrode fingers of the IDT. The depth G of the inter-electrode-finger grooves is 0.01??G?0.07?, and an electrode finger thickness H and an IDT line occupancy ? satisfy a predetermined relationship. Thus, a frequency-temperature characteristic constantly has an inflection point between a maximum value and a minimum value in an operation temperature range, thereby suppressing a fluctuation in an inflection-point temperature due to a manufacturing variation in the IDT line occupancy ?.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: May 13, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Naohisa Obata, Kunihito Yamanaka
  • Patent number: 8692439
    Abstract: A surface acoustic wave resonator has a quartz crystal substrate having Euler angles of (?=0°, 110°???150°, 88°???92°) and an IDT having a plurality of electrode fingers disposed on the quartz crystal substrate, and using a surface acoustic wave as an excitation wave, a plurality of grooves arranged in a propagation direction of the surface acoustic wave to form stripes is disposed on the quartz crystal substrate, and the electrode fingers are disposed one of between the grooves and inside the grooves.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: April 8, 2014
    Assignee: Seiko Epson Corporation
    Inventors: Takuya Owaki, Kunihito Yamanaka
  • Patent number: 8680743
    Abstract: A SAW device 11 has an IDT which is provided on the principal surface of a quartz crystal substrate 12 having Euler angles (?1.5°???1.5°, 117°???142°, 42.79°?|?|?49.57°) and excites a SAW in a stopband upper end mode, and a pair of reflectors which are arranged on both sides of the IDT. Inter-electrode-finger grooves are recessed between the electrode fingers of the IDT, and inter-conductor-strip grooves are recessed between the conductor strips of the reflectors. The wavelength ? of the SAW and the depth G of the inter-electrode-finger grooves satisfy 0.01??G. An IDT line occupancy ? and the depth G of the inter-electrode-finger grooves satisfy a predetermined relational expression. The IDT line occupancy ? and a reflector line occupancy ?r satisfy the relationship ?<?r. Therefore, an excellent frequency-temperature characteristic and a high Q value in an operation temperature range are realized simultaneously.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: March 25, 2014
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Publication number: 20140055207
    Abstract: A surface acoustic wave resonator includes a quartz crystal substrate with preselected Euler angles, and an IDT that is provided on the quartz crystal substrate, that includes a plurality of electrode fingers, and that excites a stop band upper end mode surface acoustic wave. Inter-electrode finger grooves are provided in the quartz crystal substrate between the electrode fingers in a plan view. When a wavelength of the surface acoustic wave is ?, a first film thickness of the electrode finger is H, and a first depth of the inter-electrode finger groove is G, and when a line occupation rate of convex portions of the quartz crystal substrate disposed between the inter-electrode finger grooves is ?g, and a line occupation rate of the electrode fingers disposed on the convex portions is ?e, the following relationships are satisfied 0.0407??G+H; and ?g>?e.
    Type: Application
    Filed: October 30, 2013
    Publication date: February 27, 2014
    Applicant: Seiko Epson Corporation
    Inventors: Takuya OWAKI, Kunihito YAMANAKA, Keigo IIZAWA, Kenichi HANO
  • Patent number: 8598766
    Abstract: A surface acoustic wave resonator includes a quartz crystal substrate with Euler angles (?1.5°???1.5°, 117°???142°, and 42.79°?|?|?49.57°), and an IDT provided on the quartz crystal substrate that includes a plurality of electrode fingers and excites a stop band upper end mode surface acoustic wave. Inter-electrode finger grooves are provided between the electrode fingers. If a line occupation rate of the convex portions of the quartz crystal substrate disposed between the inter-electrode finger grooves is ?g, and a line occupation rate of the electrode fingers disposed on the convex portions is ?e, ?g>?e and 0.59<?eff<0.73 are satisfied when an effective line occupation rate ?eff of the IDT is an arithmetic mean of the line occupation rate ?g and the line occupation rate ?e.
    Type: Grant
    Filed: December 2, 2011
    Date of Patent: December 3, 2013
    Assignee: Seiko Epson Corporation
    Inventors: Takuya Owaki, Kunihito Yamanaka, Keigo Iizawa, Kenichi Hano
  • Patent number: 8502625
    Abstract: A surface acoustic wave resonator includes: an IDT which is disposed on a quartz crystal substrate with an Euler angle of (?1.5°???1.5°, 117°???142°, 41.9°?|?|?49.57°) and which excites a surface acoustic wave in an upper mode of a stop band; and an inter-electrode-finger groove formed by recessing the quartz crystal substrate between electrode fingers of the IDT, wherein the following expression: 0.01??G where ? represents a wavelength of the surface acoustic wave and G represents a depth of the inter-electrode-finger groove, is satisfied and when a line occupancy of the IDT is ?, the depth of the inter-electrode-finger groove G and the line occupancy ? are set to satisfy the following expression: ?2.5×G/?+0.675????2.5×G/?+0.775.
    Type: Grant
    Filed: October 4, 2012
    Date of Patent: August 6, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8476984
    Abstract: A vibration device includes: a first vibrator having a 3rd-order function temperature characteristic in which a 3rd-order temperature coefficient is ??1, where ?1>0; and a second vibrator which is connected to the first vibrator, and has a 3rd-order function temperature characteristic in which a 3rd-order temperature coefficient is ?2, where ?2>0, wherein a difference between inflection points of the first and second vibrators is equal to or lower than 19° C., and a relationship of 0<|?1|?|2.4?2| is satisfied.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: July 2, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8471434
    Abstract: A surface acoustic wave device includes: a quartz substrate with Euler angles of (?, ?, ?); and an IDT which excites a surface acoustic wave in an upper mode of a stop band; wherein, the Euler angle ? is ?60°???60°, and the Euler angle ? determines the ranges of the Euler angles ? and ?.
    Type: Grant
    Filed: August 18, 2011
    Date of Patent: June 25, 2013
    Assignee: Seiko Epson Corporation
    Inventors: Takuya Owaki, Kunihito Yamanaka
  • Publication number: 20130027144
    Abstract: A SAW device includes a SAW chip formed of a piezoelectric substrate and an IDT formed thereon, a base substrate that supports the SAW chip, and a fixing member that fixes the SAW chip to the base substrate. The SAW chip that forms a cantilever is supported by the base substrate via the fixing member in a position where the IDT does not overlap with the fixing member in a plan view of the SAW chip. The length W of the SAW chip in a y-axis direction and the length D of the fixing member in the y-axis direction satisfy 1<D/W1?1.6. The fixing member bonds the lower surface and side surfaces of the fixed end of the SAW chip to the base substrate.
    Type: Application
    Filed: July 25, 2012
    Publication date: January 31, 2013
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Kunihito YAMANAKA, Naohisa OBATA
  • Patent number: 8358177
    Abstract: It is possible to reduce the size of a surface acoustic wave (SAW) resonator by enhancing a Q value. In a SAW resonator in which an IDT having electrode fingers for exciting SAW is disposed on a crystal substrate, the IDT includes a first region disposed at the center of the IDT and a second region and a third region disposed on both sides of the first region. A frequency is fixed in the first region and a portion in which a frequency gradually decreases as it approaches an edge of the IDT is disposed in the second region and the third region. When the frequency of the first region is Fa, the frequency at an edge of the second region is FbM, and the frequency at an edge of the third region is FcN, the variations in frequency are in the ranges of 0.9815<FbM/Fa<0.9953 and 0.9815<FcN/Fa<0.9953, respectively.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: January 22, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8344815
    Abstract: In a surface acoustic wave resonator in which an IDT having electrode fingers for exciting surface acoustic waves is formed on a crystal substrate, the line occupying ratio causing the maximum electromechanical coupling coefficient and the line occupying ratio causing the maximum reflection of the surface acoustic waves in the IDT are different from each other, the center of the IDT has the line occupying ratio causing an increase in electromechanical coupling coefficient in comparison with the edges of the IDT, and the edges of the IDT have the line occupying ratio causing an increase in reflection of the surface acoustic waves in comparison with the center of the IDT.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: January 1, 2013
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8305162
    Abstract: A surface acoustic wave resonator includes: an IDT which is disposed on a quartz crystal substrate with an Euler angle of (?1.5°???1.5°, 117°???142°, 41.9°?|?|?49.57°) and which excites a surface acoustic wave in an upper mode of a stop band; and an inter-electrode-finger groove formed by recessing the quartz crystal substrate between electrode fingers of the IDT, wherein the following expression: 0.01??G where ? represents a wavelength of the surface acoustic wave and G represents a depth of the inter-electrode-finger groove, is satisfied and when a line occupancy of the IDT is ?, the depth of the inter-electrode-finger groove G and the line occupancy ? are set to satisfy the following expression: ?2.5×G/?+0.675????2.5×G/?+0.775.
    Type: Grant
    Filed: February 25, 2010
    Date of Patent: November 6, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Patent number: 8299680
    Abstract: It is possible to reduce the size of a surface acoustic wave resonator by enhancing the Q value. In a surface acoustic wave resonator in which an IDT having electrode fingers for exciting surface acoustic waves is formed on a crystal substrate, a line occupying ratio is defined as a value obtained by dividing the width of one electrode finger by the distance between the center lines of the gaps between one electrode finger and the electrode fingers adjacent to both sides thereof, and the IDT includes a region formed by gradually changing the line occupying ratio from the center to both edges so that the frequency gradually becomes lower from the center to both edges than the frequency at the center of the IDT.
    Type: Grant
    Filed: October 22, 2009
    Date of Patent: October 30, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Publication number: 20120212301
    Abstract: A SAW resonator which, using a quartz crystal substrate with Euler angles (?1.5°???1.5°, 117°???142°, and 41.9°?|?|?49.57°), includes an IDT that excites a stop band upper end mode SAW, and an inter-electrode finger groove provided between electrode fingers configuring the IDT. When a wavelength of the SAW is ?, a first depth of the inter-electrode finger groove is G, a line occupation rate of the IDT is ?, and an electrode film thickness of the IDT is H, ?, G, ? and H satisfy the relationship of 0<H?0.005?, 0.01??G?0.09?, and 0.18???0.71.
    Type: Application
    Filed: April 30, 2012
    Publication date: August 23, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Kunihito YAMANAKA
  • Publication number: 20120139652
    Abstract: A vibration device includes: a first vibrator having a 3rd-order function temperature characteristic in which a 3rd-order temperature coefficient is ??1, where ?1>0; and a second vibrator which is connected to the first vibrator, and has a 3rd-order function temperature characteristic in which a 3rd-order temperature coefficient is ?2, where ?2>0, wherein a difference between inflection points of the first and second vibrators is equal to or lower than 19° C., and a relationship of 0<|?1|?|2.4?2| is satisfied.
    Type: Application
    Filed: December 6, 2011
    Publication date: June 7, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Kunihito YAMANAKA
  • Publication number: 20120139653
    Abstract: A surface acoustic wave resonator which can realize favorable frequency-temperature characteristics and suppress frequency variations is provided. The surface acoustic wave resonator includes a quartz crystal substrate with Euler angles (?1.5°???1.5°, 117°???142°, and 42.79°?|?|?49.57°), and an IDT that is provided on the quartz crystal substrate, includes a plurality of electrode fingers, and excites a stop band upper end mode surface acoustic wave, wherein inter-electrode finger grooves are provided between the electrode fingers in a plan view, and wherein if a line occupation rate of convex portions of the quartz crystal substrate disposed between the inter-electrode finger grooves is ?g, and a line occupation rate of the electrode fingers disposed on the convex portions is ?e, ?g>?e and 0.59<?eff<0.73 are satisfied in a case where an effective line occupation rate ?eff of the IDT is an arithmetic mean of the line occupation rate ?g and the line occupation rate ?e.
    Type: Application
    Filed: December 2, 2011
    Publication date: June 7, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventors: Takuya OWAKI, Kunihito YAMANAKA, Keigo IIZAWA, Kenichi HANO
  • Patent number: 8188635
    Abstract: A SAW resonator which, using a quartz crystal substrate with Euler angles (?1.5°???1.5°, 117°???142°, and 42.79°?|105|?49.57°, includes an IDT which excites a stop band upper end mode SAW, and grooves hollowed out of the substrate positioned between electrode fingers configuring the IDT, wherein, when the wavelength of the SAW is ? and the depth of the inter-electrode finger grooves is G, ? and G satisfy the relationship of 0.01??G and wherein, when the line occupation rate of the IDT is ?, the groove depth G and line occupation rate ? satisfy the relationships of ?2.0000×G/?+0.7200????2.5000×G/?+0.7775 provided that 0.0100??G?0.0500?, ?3.5898×G/?+0.7995????2.5000+G/?+0.7775 provided that 0.0500?<G?0.0695?.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: May 29, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Kunihito Yamanaka
  • Publication number: 20120105165
    Abstract: A surface acoustic wave resonator includes a piezoelectric substrate and an interdigital transducer (IDT) that includes electrode fingers exciting a surface acoustic wave on the piezoelectric substrate, a first region at a center of the IDT, and a second region and a third region at opposite sides of the IDT. In the IDT, a line occupation rate at which an electromechanical coupling coefficient becomes a maximum is different from the line occupation rate at which reflection of the surface acoustic wave becomes a maximum.
    Type: Application
    Filed: November 29, 2011
    Publication date: May 3, 2012
    Applicant: SEIKO EPSON CORPORATION
    Inventor: Kunihito YAMANAKA