Patents by Inventor Yoshifumi Nakajima

Yoshifumi Nakajima 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: 8246485
    Abstract: A golf club shaft has a more attractive appearance than a coating of plating and also achieves a rustproofing effect within the shaft, while avoiding the problem of an increase in weight and processing of effluents associated with plated shafts. The golf club shaft has a shaft body, a covering film formed by chemical treatment of an outside surface and an inside surface of the shaft body, a coating film layer formed by electric painting on the covering film of at least the outside surface; and a pigment layer, in which a polarizing powder is dispersed, which is coated on the coating film layer.
    Type: Grant
    Filed: December 10, 2009
    Date of Patent: August 21, 2012
    Assignee: Bridgestone Sports Co., Ltd.
    Inventors: Toshimitsu Miura, Yoshifumi Nakajima
  • Publication number: 20120129624
    Abstract: A golf club grip having a double construction includes a cylindrical inside layer part made of a first rubber having a first hardness, and a cylindrical outside layer part made of a second rubber having a second hardness lower than the first hardness, which part covers the cylindrical inside layer part. The cylindrical inside layer part has a length 1 to 4 cm longer than the length of a half of the entire length of the grip. The cylindrical inside layer part is provided with a plurality of longitudinal projecting strips formed on the outer peripheral surface thereof, and the plurality of longitudinal projecting strips extend from the proximal end side of the cylindrical inside layer part to a portion of 70 to 80% of the entire length of the cylindrical inside layer part along the axis line direction of the cylindrical inside layer part, and are formed at fixed intervals in the circumferential direction.
    Type: Application
    Filed: September 22, 2011
    Publication date: May 24, 2012
    Applicant: BRIDGESTONE SPORTS CO., LTD
    Inventors: Hiromasa ITO, Yoshifumi NAKAJIMA, Tadahiro TAKECHI
  • Publication number: 20110065526
    Abstract: A golf club shaft has a function of attenuating the vibration of the shaft at the time of impact and also having a function of stabilizing the struck ball. A shaft has an inner bias layer having a fiber direction that was inclined with respect the shaft axial direction and an outer bias layer having a fiber direction that is inclined with respect to the shaft axial direction in a direction opposite from that of the inner bias layer laminated as a fiber-reinforced resin layer, and a vibration-damping material sheet layer having a vertical-direction length of about 110 mm to about 150 mm disposed between the inner bias layer and the outer bias layer, with region of the position of the end of the grip attachment location as the rear end in the vertical direction.
    Type: Application
    Filed: August 19, 2010
    Publication date: March 17, 2011
    Applicant: BRIDGESTONE SPORTS CO., LTD.
    Inventor: Yoshifumi Nakajima
  • Publication number: 20110028232
    Abstract: A golf club includes a shaft in which a brightness of a color of the shaft from a grip side toward a head side is changed from darkness to brightness in a plurality of stages.
    Type: Application
    Filed: July 30, 2010
    Publication date: February 3, 2011
    Applicant: BRIDGESTONE SPORTS CO., LTD.
    Inventors: Yoshifumi NAKAJIMA, Takaharu TAKECHI, Tomoe WATANABE, Daisuke HORII
  • Publication number: 20100267464
    Abstract: A golf club shaft has a more attractive appearance than a coating of plating and also achieves a rustproofing effect within the shaft, while avoiding the problem of an increase in weight and processing of effluents associated with plated shafts. The golf club shaft has a shaft body, a covering film formed by chemical treatment of an outside surface and an inside surface of the shaft body, a coating film layer formed by electric painting on the covering film of at least the outside surface; and a pigment layer, in which a polarizing powder is dispersed, which is coated on the coating film layer.
    Type: Application
    Filed: December 10, 2009
    Publication date: October 21, 2010
    Applicant: BRIDGESTONE SPORTS CO., LTD.
    Inventors: Toshimitsu MIURA, Yoshifumi Nakajima
  • Patent number: 7338386
    Abstract: A light-weighted golf club shaft, which can stabilize the swing orbit of a club head during a swing and can allow a player to swing a golf club easily and to have a consistent shot pattern, is provided. The golf club shaft has a length of 42 to 48 inches and a weight of 35 to 50 grams. A center of gravity of the shaft is located within 46.0 to 49.0% of its entire length from its tip end and a torque to the tip-end of the shaft ranges between 3.0 and 4.5 degrees. The shaft may comprise a longitudinal layer and a biased layer. The biased layer may comprise carbon fibers having a modulus of elasticity of not less than 40 t/mm2. The ratio of the number of turns of prepreg sheets for the biased layer in the tip-end portion to that in the butt-end portion of the shaft may range between 3:1 and 3:2.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: March 4, 2008
    Assignee: Bridgestone Sports Co., Ltd.
    Inventor: Yoshifumi Nakajima
  • Publication number: 20070117647
    Abstract: A light-weighted golf club shaft, which can stabilize the swing orbit of a club head during a swing and can allow a player to swing a golf club easily and to have a consistent shot pattern, is provided. The golf club shaft has a length of 42 to 48 inches and a weight of 35 to 50 grams. A center of gravity of the shaft is located within 46.0 to 49.0% of its entire length from its tip end and a torque to the tip-end of the shaft ranges between 3.0 and 4.5 degrees. The shaft may comprise a longitudinal layer and a biased layer. The biased layer may comprise carbon fibers having a modulus of elasticity of not less than 40 t/mm2. The ratio of the number of turns of prepreg sheets for the biased layer in the tip-end portion to that in the butt-end portion of the shaft may range between 3:1 and 3:2.
    Type: Application
    Filed: February 28, 2006
    Publication date: May 24, 2007
    Inventor: Yoshifumi Nakajima
  • Patent number: 7029402
    Abstract: A golf club shaft tip diameter adjuster attached to a tip portion of a golf club shaft for adjusting a diameter of the shaft tip portion. The golf club shaft tip diameter adjuster is formed into a cylindrical tubular body out of fiber reinforced resin. A slit is defined to separate the tip diameter adjuster in the lengthwise direction thereof.
    Type: Grant
    Filed: January 16, 2003
    Date of Patent: April 18, 2006
    Assignee: Bridgestone Sports Co., Ltd.
    Inventor: Yoshifumi Nakajima
  • Patent number: 6801091
    Abstract: An oscillator controller which optimizes key circuit parameters of an excitation circuit according to the operating condition of a discharge lamp. An excitation circuit energizes a discharge lamp to produce a light beam for pumping atoms, as part of a mechanism of atomic resonance detection. The operation of the excitation circuit is monitored by a start-up voltage monitor, which asserts a voltage monitoring signal when the excitation circuit's start-up voltage is reached. A light amount monitor receives a resonance detection signal from a light sensing device to check the amount of light before and after the discharge lamp lights up. The resultant light amount monitoring signal indicates this information. Based on the two monitoring signals, a bias voltage selector selects an appropriate bias voltage that varies circuit parameters of the excitation circuit.
    Type: Grant
    Filed: December 10, 2002
    Date of Patent: October 5, 2004
    Assignee: Fujitsu Limited
    Inventors: Ken Atsumi, Hideyuki Matsuura, Yoshifumi Nakajima, Yoshito Koyama
  • Publication number: 20030162605
    Abstract: A golf club shaft tip diameter adjuster attached to a tip portion of a golf club shaft for adjusting a diameter of the shaft tip portion. The golf club shaft tip diameter adjuster is formed into a cylindrical tubular body out of fiber reinforced resin. A slit is defined to separate the tip diameter adjuster in the lengthwise direction thereof.
    Type: Application
    Filed: January 16, 2003
    Publication date: August 28, 2003
    Applicant: BRIDGESTONE SPORTS CO., LTD.
    Inventor: Yoshifumi Nakajima
  • Publication number: 20030146797
    Abstract: An oscillator controller which optimizes key circuit parameters of an excitation circuit according to the operating condition of a discharge lamp. An excitation circuit energizes a discharge lamp to produce a light beam for pumping atoms, as part of a mechanism of atomic resonance detection. The operation of the excitation circuit is monitored by a start-up voltage monitor, which asserts a voltage monitoring signal when the excitation circuit's start-up voltage is reached. A light amount monitor receives a resonance detection signal from a light sensing device to check the amount of light before and after the discharge lamp lights up. The resultant light amount monitoring signal indicates this information. Based on the two monitoring signals, a bias voltage selector selects an appropriate bias voltage that varies circuit parameters of the excitation circuit.
    Type: Application
    Filed: December 10, 2002
    Publication date: August 7, 2003
    Inventors: Ken Atsumi, Hideyuki Matsuura, Yoshifumi Nakajima, Yoshito Koyama
  • Patent number: 6570455
    Abstract: A rubidium atom oscillator is not influenced by a circumference noise or the like, and is excellent in the short-term stability and the phase noise characteristic. A crystal oscillator oscillates a fixed frequency as an atomic resonance frequency. A direct digital synthesizer inputs an output of the crystal oscillator as a system clock and also inputs tuned data corresponding to an error signal generated according to a resonance frequency so as to carry out a variable control of an output frequency. A frequency synthesizer synthesizes and multiplies an output of the direct digital synthesizer and applies a phase modulation with a low-frequency signal. An atomic resonator inputs an output of the frequency synthesizer and detects an error signal with respect to a resonance frequency of rubidium atoms. A tuned-data generating circuit inputs the error signal from the atomic resonator so as to generate the tuned data corresponding to the error signal.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: May 27, 2003
    Assignee: Fujitsu Limited
    Inventors: Ken Atsumi, Hideyuki Matsuura, Yoshifumi Nakajima, Yoshito Koyama
  • Publication number: 20020125959
    Abstract: A rubidium atom oscillator is not influenced by a circumference noise or the like, and is excellent in the short-term stability and the phase noise characteristic. A crystal oscillator oscillates a fixed frequency as an atomic resonance frequency. A direct digital synthesizer inputs an output of the crystal oscillator as a system clock and also inputs tuned data corresponding to an error signal generated according to a resonance frequency so as to carry out a variable control of an output frequency. A frequency synthesizer synthesizes and multiplies an output of the direct digital synthesizer and applies a phase modulation with a low-frequency signal. An atomic resonator inputs an output of the frequency synthesizer and detects an error signal with respect to a resonance frequency of rubidium atoms. A tuned-data generating circuit inputs the error signal from the atomic resonator so as to generate the tuned data corresponding to the error signal.
    Type: Application
    Filed: September 27, 2001
    Publication date: September 12, 2002
    Inventors: Ken Atsumi, Hideyuki Matsuura, Yoshifumi Nakajima, Yoshito Koyama
  • Patent number: 6300841
    Abstract: In an atomic oscillator, a high-frequency converting circuit converts the output of a standard oscillator into a high frequency signal such that the frequency of the high frequency signal multiplied by a low natural number equals an atomic resonant frequency signal. The high frequency signal is then multiplied by a low natural number in an active, low-natural-number multiplier circuit to convert the output frequency of the standard oscillator into a resonant frequency to be input to the atomic oscillator. The result is that, without using a passive, high-natural-number multiplier circuit, such as a varactor diode, which is expensive, it is possible to convert the output frequency of the standard oscillator into a resonant frequency signal of a rubidium atom, thus downsizing the circuits of the atomic oscillator and reducing the term and cost of manufacture.
    Type: Grant
    Filed: March 28, 2000
    Date of Patent: October 9, 2001
    Assignee: Fujitsu Limited
    Inventors: Ken Atsumi, Hideyuki Matsuura, Yoshifumi Nakajima, Yoshito Koyama, Koji Nakamuta, Minoru Sakai
  • Patent number: 5751193
    Abstract: A rubidium atomic oscillator includes a voltage-controlled oscillator (VCO) producing a first microwave signal for an output, and a light source producing pumping light of which the wavelength is externally controlled. The oscillator further includes a division part for dividing the pumping light into a first light and a second light, a wavelength shift part changing a wavelength of the second light to produce a third light, and a cavity resonator, oscillated by a second microwave signal, which absorbs the first light and the third light, the cavity resonator having a resonance cell filled with a rubidium gas. In an electrical control part, the second microwave signal is produced based on the first microwave signal from the VCO, a level of the first light passed through the cavity resonator is detected, and a frequency of the VCO is controlled so that the first light is maximally absorbed in the cavity resonator.
    Type: Grant
    Filed: April 26, 1996
    Date of Patent: May 12, 1998
    Assignee: Fujitsu Limited
    Inventors: Yoshifumi Nakajima, Yoshito Koyama
  • Patent number: 5712597
    Abstract: A rubidium atom oscillator has an increased allowable temperature range in which a frequency fluctuation due to change in the ambient temperature is suppressed. The frequency is stabilized in an increased temperature range as compared to the conventional rubidium atom oscillator. The rubidium atom oscillator oscillates a microwave having a predetermined stable frequency by using an optical pumping effect of rubidium gas. A rubidium lamp radiates a resonance light. A cavity resonator accommodates a gas cell containing rubidium gas and a photodetector detecting an amount of the resonance light passing through the gas cell. It is determined whether or not an ambient temperature of the cavity resonator is within a predetermined temperature range between a lower-limit temperature and an upper-limit temperature. A temperature correction signal is generated based on the determination. A current determined by the temperature correction signal is supplied to a coil surrounding the cavity resonator.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: January 27, 1998
    Assignee: Fujitsu Limited
    Inventors: Ken Atsumi, Yoshifumi Nakajima, Yoshito Koyama
  • Patent number: 5063568
    Abstract: A wavelength stabilized light source includes a laser diode which emits a laser beam of a wavelength of 1.56 .mu.m. A second-harmonic generator generates a second-harmonic light of the laser beam. The second-harmonic light enters a resonator which includes a resonance cell in which .sup.87 Rb atoms are filled. A phase-modulated microwave is irradiated on said resonator. The reasonator outputs a double resonance signal when the wavelength of the second-harmonic light is equal to a resonance wavelength of .sup.87 Rb and the frequency of the microwave is equal to a transition frequency of .sup.87 Rb. A first control circuit controls the microwave so that the frequency of the microwave is equal to the transition frequency. A second control circuit controls the laser diode so that the wavelength of the second-harmonic light is equal to the resonance wavelength of .sup.87 Rb. Thereby, the wavelength of the emitted laser beam is stabilized at 1.56 .mu.m.
    Type: Grant
    Filed: May 4, 1990
    Date of Patent: November 5, 1991
    Assignee: Fujitsu Limited
    Inventors: Kazuharu Chiba, Yoshifumi Nakajima, Hideo Sumiyoshi
  • Patent number: 4914403
    Abstract: A cesium oscillator includes a cesium beam tube, and an oscillator circuit which generates an oscillation signal of a frequency to be supplied to the cesium beam tube. A frequency control circuit including a sweep circuit and a feedback loop circuit continuously varies the frequency of the oscillation signal. The frequency of the oscillation signal is continuously varied two times when the frequency of the oscillation signal is to be adjusted. A hold circuit holds the highest signal level of the resonance signal supplied from the cesium beam tube when the frequency control circuit continuously varies the frequency of the oscillation signal first. A control circuit controls the frequency control circuit so as to stop continuously varying the frequency when a signal level of the resonance signal obtained by continuously varying the frequency of the oscillation signal by the frequency control circuit for the second time becomes equal to the highest signal level held by the hold circuit.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: April 3, 1990
    Assignee: Fujitsu Limited
    Inventors: Yoshifumi Nakajima, Kazuharu Chiba, Hideo Sumiyoshi