Patents by Inventor Hirofumi Kawashima

Hirofumi Kawashima 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).

  • Publication number: 20110062832
    Abstract: A quartz crystal unit comprising a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase and having a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, an electrode being disposed on each of two of side surfaces of each of the first and second quartz crystal tuning fork tines so that the electrode disposed on each of two of the side surfaces of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the electrode disposed on each of two of the side surfaces of the second quartz crystal tuning fork tine, a motional capacitance C1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator being greater than a motional capacitance C2 of a second overtone mode of vibration thereof.
    Type: Application
    Filed: November 10, 2010
    Publication date: March 17, 2011
    Inventor: Hirofumi Kawashima
  • Publication number: 20100308699
    Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least one quartz crystal oscillator. Also, the at least one oscillator comprises a quartz crystal oscillating circuit comprising an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a length-extensional mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.
    Type: Application
    Filed: July 22, 2010
    Publication date: December 9, 2010
    Inventor: Hirofumi Kawashima
  • Publication number: 20100308698
    Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least one quartz crystal oscillator. Also, the at least one oscillator comprises a quartz crystal oscillating circuit comprising an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a length-extensional mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.
    Type: Application
    Filed: July 22, 2010
    Publication date: December 9, 2010
    Inventor: Hirofumi Kawashima
  • Patent number: 7845063
    Abstract: A method for manufacturing a quartz crystal unit comprises forming a quartz crystal tuning fork resonator that is capable of vibrating in a flexural mode of an inverse phase and that has a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base. An electrode is disposed on each of two of side surfaces of each of the first and second quartz crystal tuning fork tines so that the electrodes of the first quartz crystal tuning fork tine have an electrical polarity opposite to an electrical polarity of the electrodes of the second quartz crystal tuning fork tine, a motional capacitance C1 of a fundamental mode of vibration of the quartz crystal tuning fork resonator being greater than a motional capacitance C2 of a second overtone mode of vibration thereof.
    Type: Grant
    Filed: February 14, 2008
    Date of Patent: December 7, 2010
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Publication number: 20100301958
    Abstract: A unit comprising a quartz crystal resonator vibratable in a flexural mode and having a base portion including a length less than 0.5 mm, and first and second vibrational arms connected to the base portion, at least one groove being formed in each of two of opposite main surfaces of each of the first and second vibrational arms, and an electrode being disposed on a surface of the at least one groove formed in each of the two of the opposite main surfaces of each of the first and second vibrational arms so that the electrode disposed on the surface of the at least one groove formed in each of the two of the opposite main surfaces of the first vibrational arm has an electrical polarity opposite to an electrical polarity of the electrode disposed on the surface of the at least one groove formed in each of the two of the opposite main surfaces of the second vibrational arm.
    Type: Application
    Filed: June 8, 2010
    Publication date: December 2, 2010
    Inventor: Hirofumi Kawashima
  • Patent number: 7779530
    Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least one quartz crystal oscillator. Also, the at least one oscillator comprises a quartz crystal oscillating circuit comprising an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a length-extensional mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: August 24, 2010
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Patent number: 7768179
    Abstract: A quartz crystal unit comprising a case having an interior space and a mounting portion in the interior space, and a quartz crystal resonator having a base portion and first and second vibrational arms, the quartz crystal resonator being vibratable in a flexural mode, a capacitance ratio r1 of a fundamental mode of vibration of the quartz crystal resonator being less than a capacitance ratio r2 of a second overtone mode of vibration thereof, a mounting arm protruding from the base portion and extending in a common direction with at least one of the first and second vibrational arms, the mounting arm being mounted on the mounting portion of the case, an electrode being disposed on a surface of the mounting arm and a surface in the interior space of the case, the electrode disposed on the surface of the mounting arm being connected to the electrode disposed on the surface in the interior space of the case.
    Type: Grant
    Filed: March 6, 2008
    Date of Patent: August 3, 2010
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Patent number: 7723904
    Abstract: An electronic apparatus comprises a display portion and at least one oscillating circuit comprising an amplifier, at least one resistor, a plurality of capacitors, and a unit having a case and a resonator. The resonator is vibratable in a flexural mode and has first and second vibrational arms, and at least one groove is formed in at least one of opposite main surfaces of each of the first and second vibrational arms, and at least one mounting arm protrudes from the base portion and extends in a common direction with at least one of the first and second vibrational arms. An output signal of the at least one oscillating circuit comprising the resonator is a clock signal for use in operation of the electronic apparatus to display time information at the display portion.
    Type: Grant
    Filed: January 17, 2008
    Date of Patent: May 25, 2010
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Publication number: 20100117492
    Abstract: In a unit comprising a quartz crystal resonator, a case having a mounting portion, and a lid connected to the case, the quartz crystal resonator having a base portion, and first and second vibrational arms connected to the base portion, at least one groove being formed in at least one of opposite main surfaces of each of the first and second vibrational arms, at least one mounting arm being connected to the base portion having a length L1 less than 0.5 mm and extending in a common direction with at least one of the first and second vibrational arms, the at least one mounting arm being mounted on the mounting portion of the case.
    Type: Application
    Filed: January 14, 2010
    Publication date: May 13, 2010
    Inventor: Hirofumi Kawashima
  • Publication number: 20090261923
    Abstract: A quartz crystal unit has a quartz crystal tuning fork resonator that is capable of vibrating in a flexural mode and that has a quartz crystal tuning fork base, and first and second quartz crystal tuning fork tines. The quartz crystal tuning fork resonator is mounted on a mounting portion of the case after which the oscillation frequency of the quartz crystal tuning fork resonator is adjusted. The quartz crystal unit comprising the quartz crystal tuning fork resonator has a series resistance R1 of a fundamental mode of vibration less than a series resistance R2 of a second overtone mode of vibration. At least one groove is formed in at least one of opposite main surfaces of each of the first and second quartz crystal tuning fork tines so that a width of the at least one groove is greater than a distance in the width direction of the at least one groove measured from an outer edge of the at least one groove to an outer edge of the corresponding one of the first and second quartz crystal tuning fork tines.
    Type: Application
    Filed: June 25, 2009
    Publication date: October 22, 2009
    Inventor: Hirofumi Kawashima
  • Publication number: 20090257320
    Abstract: An electronic apparatus comprises a display portion and at least one oscillating circuit comprising an amplifier, at least one resistor, a plurality of capacitors, and a unit having a case and a resonator. The resonator is vibratable in a flexural mode and has first and second vibrational arms, and at least one groove is formed in at least one of opposite main surfaces of each of the first and second vibrational arms, and at least one mounting arm protrudes from the base portion and extends in a common direction with at least one of the first and second vibrational arms. An output signal of the at least one oscillating circuit comprising the resonator is a clock signal for use in operation of the electronic apparatus to display time information at the display portion.
    Type: Application
    Filed: January 17, 2008
    Publication date: October 15, 2009
    Inventor: Hirofumi Kawashima
  • Publication number: 20090201061
    Abstract: A method for manufacturing a quartz crystal unit comprises the steps of forming a quartz crystal tuning fork resonator vibratable in a flexural mode of an inverse phase and having a quartz crystal tuning fork base and first and second quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, forming at least one groove having at least three stepped portions in at least one of opposite main surfaces of each of first and second quartz crystal tuning fork tines, disposing an electrode on a surface of one of the at least three stepped portions of the at least one groove and an electrode on one of opposite side surfaces of each of the first and second quartz crystal tuning fork tines, mounting the quartz crystal tuning fork resonator on a mounting portion of a case, and connecting a lid to the case to cover an open end of the case, wherein the step of forming the quartz crystal tuning fork base and the first and second quartz crystal tuning fork tines is performed before the step of formin
    Type: Application
    Filed: April 16, 2009
    Publication date: August 13, 2009
    Inventor: Hirofumi Kawashima
  • Publication number: 20090201062
    Abstract: A method for manufacturing a quartz crystal unit comprises the steps of adjusting an oscillation frequency of a quartz crystal tuning fork resonator that is vibratable in a flexural mode of an inverse phrase and that has first and second quartz crystal tuning fork tines, forming at least one groove in each of two of opposite main surfaces of each of first and second quartz crystal tuning fork tines, disposing an electrode on a surface of the at least one groove formed in each of two of the opposite main surfaces and each of two of opposite side surfaces of each of the first and second quartz crystal tuning fork tines so that the electrodes of the grooves of the first quartz crystal tuning fork tine are connected to the electrodes of the side surfaces of the second quartz crystal tuning fork tine and the electrodes of the grooves of the second quartz crystal tuning fork tine are connected to the electrodes of the side surfaces of the first quartz crystal tuning fork tine, the quartz crystal tuning fork resonat
    Type: Application
    Filed: April 16, 2009
    Publication date: August 13, 2009
    Inventor: Hirofumi Kawashima
  • Patent number: 7564326
    Abstract: An electronic apparatus comprises at least one quartz crystal oscillator comprised of a quartz crystal oscillating circuit having a quartz crystal resonator, an amplifier, at least one resistor, and capacitors. The quartz crystal resonator comprises a quartz crystal tuning fork resonator having a quartz crystal tuning fork base, quartz crystal tuning fork tines connected to the quartz crystal tuning fork base, and at least one groove formed in at least one of opposite main surfaces of the quartz crystal tuning fork tines. A length of the at least one groove formed in at least one of the opposite main surfaces of the quartz crystal tuning fork tines is within a range of 40% to 80% of a length of the quartz crystal tuning fork tines.
    Type: Grant
    Filed: June 25, 2007
    Date of Patent: July 21, 2009
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Patent number: 7536768
    Abstract: In a method for manufacturing quartz crystal unit, a quartz crystal oscillator and an electronic apparatus, the method comprises the steps of forming at least triple and in different steps a quartz crystal tuning fork resonator having a frequency of oscillation of a fundamental mode of vibration, the quartz crystal tuning fork resonator having a quartz crystal tuning fork base and first and second quartz crystal tuning fork tines each connected to the quartz crystal tuning fork base, each of the first and second quartz crystal tuning fork tines having a first main surface and a second main surface opposite the first main surface, and a first side surface and a second side surface opposite the first side surface; providing a case having a mounting portion and an open end; providing a lid for covering the open end of the case; mounting the quartz crystal tuning fork resonator on the mounting portion of the case; and connecting the lid to the case to cover the open end thereof.
    Type: Grant
    Filed: August 5, 2005
    Date of Patent: May 26, 2009
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Patent number: 7528682
    Abstract: In an electronic apparatus comprising a digital display portion and first and second oscillators comprising first and second oscillating circuits, each of the first and second oscillating circuits having a resonator, an amplifier, a plurality of capacitors, and at least one resistor, a mode of vibration of the resonator of the first oscillating circuit being the same as that of the resonator of the second oscillating circuit, an output signal being output from each of the first and second oscillating circuits, the output signal of one of the first and second oscillating circuits being a clock signal for use in operation of the electronic apparatus to display time information at the digital display portion.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: May 5, 2009
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima
  • Publication number: 20090102327
    Abstract: A quartz crystal unit comprising a case having an interior space and a mounting portion in the interior space, and a quartz crystal resonator having a base portion and first and second vibrational arms, the quartz crystal resonator being vibratable in a flexural mode, a capacitance ratio r1 of a fundamental mode of vibration of the quartz crystal resonator being less than a capacitance ratio r2 of a second overtone mode of vibration thereof, a mounting arm protruding from the base portion and extending in a common direction with at least one of the first and second vibrational arms, the mounting arm being mounted on the mounting portion of the case, an electrode being disposed on a surface of the mounting arm and a surface in the interior space of the case, the electrode disposed on the surface of the mounting arm being connected to the electrode disposed on the surface in the interior space of the case.
    Type: Application
    Filed: March 6, 2008
    Publication date: April 23, 2009
    Inventor: Hirofumi Kawashima
  • Publication number: 20090038131
    Abstract: A quartz crystal unit comprises a quartz crystal tuning fork resonator capable of vibrating in a flexural mode of an inverse phase and having at least one groove having at least one stepped portion formed in at least one of opposite main surfaces of each of first and second quartz crystal tuning fork tines. An electrode is disposed on the at least one stepped portion of the at least one groove so that the electrode of the first quartz crystal tuning fork tine has an electrical polarity opposite to an electrical polarity of the electrode of the second quartz crystal tuning fork tine. The quartz crystal unit comprising the quartz crystal tuning fork resonator has a capacitance ratio r1 of a fundamental mode of vibration less than a capacitance ratio r2 of a second overtone mode of vibration.
    Type: Application
    Filed: October 2, 2008
    Publication date: February 12, 2009
    Inventor: Hirofumi Kawashima
  • Publication number: 20080284281
    Abstract: The electronic apparatus comprises a display portion and a quartz crystal oscillator at least, and said electronic apparatus comprises at least one quartz crystal oscillator. Also, the at least one oscillator comprises a quartz crystal oscillating circuit comprising an amplification circuit and a feedback circuit. The feedback circuit is constructed by a flexural mode, quartz crystal tuning fork resonator or a length-extensional mode quartz crystal resonator and for example, the quartz crystal tuning fork resonator comprising tuning fork tines and tuning fork base that are formed integrally, is shown with novel shape and electrode construction. Also, the quartz crystal tuning fork resonator, capable of vibrating in a fundamental mode and having a high frequency stability can be provided with a small series resistance and a high quality factor, even when the tuning fork resonator is miniaturized.
    Type: Application
    Filed: January 17, 2008
    Publication date: November 20, 2008
    Inventor: Hirofumi Kawashima
  • Patent number: RE41671
    Abstract: A quartz crystal tuning fork resonator has quartz crystal tuning fork tines for undergoing vibration in an inverse phase. Each of the quartz crystal tuning fork tines has a first main surface and a second main surface opposite the first main surface, each of the first and second main surfaces having a central linear portion. The quartz crystal tuning fork tines extend from a quartz crystal tuning fork base. At least one groove is formed in the central linear portion of each of the first and second main surfaces of each of the quartz crystal tuning fork tines. A width of the groove in the central linear portion of one of the first and second main surfaces of each of the quartz crystal tuning fork tines is greater than or equal to a distance in the width direction of the groove measured from an outer edge of the groove to an outer edge of the tuning fork tine.
    Type: Grant
    Filed: June 14, 2007
    Date of Patent: September 14, 2010
    Assignee: Piedek Technical Laboratory
    Inventor: Hirofumi Kawashima