Patents by Inventor Junichiro Yamakawa
Junichiro Yamakawa 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).
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Patent number: 9320684Abstract: The present invention discloses a dental restorative material comprising 10-50 mass % of (A) a polymerizable monomer, 5-80 mass % of (B) an organic-inorganic composite filler which is prepared by dispersing an inorganic fine filler having an average particle diameter of 1 ?m or smaller in an organic matrix and has an average particle diameter of 5.0-50 ?m, and 10-60 mass % of (C) a third component, i.e., an inorganic filler having an average particle diameter of 1.1-5.0 ?m, wherein the absolute value of the difference between the refractive index [nC] of the inorganic filler (C) and the refractive index [nB] of the organic-inorganic composite filler (B) (i.e., |nC?nB|) is 0.005-0.07 at 32° C. and the absolute value of the difference between the refractive index [nA] of the cured product of the polymerizable monomer (A) and the refractive index [nC] of the inorganic filler (C) (i.e., |nA?nC|) is 0.005-0.05 at 32° C.Type: GrantFiled: June 22, 2012Date of Patent: April 26, 2016Assignee: TOKUYAMA DENTAL CORPORATIONInventors: Nobuyuki Isizaka, Tatsuya Yamazaki, Junichiro Yamakawa
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Publication number: 20140206792Abstract: The present invention discloses a dental restorative material comprising 10-50 mass % of (A) a polymerizable monomer, 5-80 mass % of (B) an organic-inorganic composite filler which is prepared by dispersing an inorganic fine filler having an average particle diameter of 1 ?m or smaller in an organic matrix and has an average particle diameter of 5.0-50 ?m, and 10-60 mass % of (C) a third component, i.e., an inorganic filler having an average particle diameter of 1.1-5.0 ?m, wherein the absolute value of the difference between the refractive index [nC] of the inorganic filler (C) and the refractive index [nB] of the organic-inorganic composite filler (B) (i.e., |nC?nB|) is 0.005-0.07 at 32° C. and the absolute value of the difference between the refractive index [nA] of the cured product of the polymerizable monomer (A) and the refractive index [nC] of the inorganic filler (C) (i.e., |nA?nC|) is 0.005-0.05 at 32° C.Type: ApplicationFiled: June 22, 2012Publication date: July 24, 2014Applicant: TOKUYAMA DENTAL CORPORATIONInventors: Nobuyuki Ishizaka, Tatsuya Yamazaki, Junichiro Yamakawa
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Patent number: 8547183Abstract: There is provided a voltage controlled oscillator that is compact and can be manufactured at low cost. The voltage controlled oscillator is structured to include: a resonance part including a variable capacitance element and an inductance element, the variable capacitance element having a capacitance that varies according to a control voltage for frequency control input from an external part, and a series resonant frequency of the resonance part being adjusted according to the capacitance; an amplifying part amplifying a frequency signal from the resonance part; and a feedback part including a capacitance element for feedback and feeding the frequency signal amplified by the amplifying part back to the resonance part to form an oscillation loop together with the amplifying part and the resonance part, wherein the amplifying part is provided in an integrated circuit chip, and the resonance part and the capacitance element for feedback are formed as circuit components separate from the integrated circuit chip.Type: GrantFiled: September 29, 2010Date of Patent: October 1, 2013Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Junichiro Yamakawa, Kazuo Akaike, Mikio Takano, Hiroshi Hoshigami, Kenji Kawahata, Kietsu Saito, Yasushi Yamamoto, Tatsunori Onzuka, Toshimasa Tsuda, Susumu Yoshimoto
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Patent number: 8416028Abstract: To provide a voltage controlled oscillator having small size and capable of obtaining a low phase noise characteristic over a large span of adjustable range of frequency. A quartz crystal having a characteristic (dielectric loss tangent: tan ?) better than that of fluorocarbon resin, LTCC or the like conventionally used as a substrate of a resonance part, and on which a fine pattern of metal film can be formed through a photolithography method, is used as a quartz-crystal substrate, and a conductive line is formed on the quartz-crystal substrate to form an inductance element in the resonance part. Accordingly, since the resonance part having a high Q value can be formed, it is possible to obtain a voltage controlled oscillator having small size and low loss over a wide frequency range.Type: GrantFiled: September 28, 2010Date of Patent: April 9, 2013Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Junichiro Yamakawa, Kazuo Akaike, Tatsunori Onzuka, Toshimasa Tsuda, Mikio Takano, Yasushi Yamamoto, Susumu Yoshimoto
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Patent number: 8283989Abstract: There is provided a voltage controlled oscillator using a Colpitts circuit capable of suppressing deterioration (decrease) in variable range (adjustable range) of an output frequency due to the influence of an inductance component on a conductive line, which connects a connection point between two capacitors of a feedback part and an emitter of a transistor. In a VCO using a Colpitts circuit, with respect to capacitors 22, 23 of a feedback part 2, a first feedback capacitance element (capacitor) 22 is disposed so as to directly couple a terminal for base (connection part 7) and a terminal for emitter on a base substrate 5, to which a terminal part 8 (T1) extending from a base of a transistor 21 and a terminal part 8 (T2) extending from an emitter of the transistor 21 are fitted, respectively, and a second feedback capacitance element (capacitor) 23 is disposed so as to directly couple the terminal for emitter and the terminal for grounding (ground electrode 51).Type: GrantFiled: September 28, 2010Date of Patent: October 9, 2012Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Tatsunori Onzuka, Junichiro Yamakawa, Toshimasa Tsuda, Kenji Kawahata, Hiroshi Hoshigami
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Patent number: 8277731Abstract: To shorten the time required for an oscillation frequency to stabilize in a sensing device sensing a substance to be sensed by using the fact that a natural frequency of a piezoelectric resonator changes when the substance to be sensed is adsorbed by an adsorption layer formed on the piezoelectric resonator. A sensing device includes: an oscillator circuit 4 oscillating a quartz-crystal resonator 12; and an intense excitation circuit that is formed by the oscillator circuit 4 including a series circuit of a resistor 52 and a third transistor 53 of PNP type and that intensely excites the quartz-crystal resonator 12 connected to the oscillator circuit 4 for a period of time preset by a one-shot circuit 22 by supplying the quartz-crystal resonator 12 with high power equal to or more than twice regular power supplied at the time of the measurement of the substance to be sensed, to stabilize the oscillation of the quartz-crystal resonator 12.Type: GrantFiled: April 14, 2010Date of Patent: October 2, 2012Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Tomoya Yorita, Junichiro Yamakawa, Shigenori Watanabe, Mitsuaki Koyama
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Patent number: 8176773Abstract: To provide a piezoelectric sensor in which a first electrode for measurement and a second electrode for reference are provided apart from each other on one surface side of a piezoelectric piece and a common electrode is provided on an opposite surface side so as to face the first and second electrodes. A piezoelectric sensor includes: a first electrode for measurement and a second electrode for reference provided apart from each other on one surface side of a piezoelectric piece; a common electrode provided on an opposite surface side of the piezoelectric piece commonly for the first electrode and the second electrode to face the first electrode and the second electrode; and an adsorption layer formed on an area, of the common electrode, to which the first electrode is faced across the piezoelectric piece, to adsorb a substance to be sensed.Type: GrantFiled: May 19, 2009Date of Patent: May 15, 2012Assignee: Nihon Dempa Kogyo Co., Ltd.Inventors: Junichiro Yamakawa, Kazuo Akaike, Takeru Mutoh, Hiroyuki Kukita
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Publication number: 20120038425Abstract: A resonance part of a voltage controlled oscillator (VCO) includes variable capacitance elements where an electrostatic capacitance changes in order to adjust a resonance frequency and an inductance element, and a transistor of grounded emitter type amplifies a frequency signal inputted from the resonance part to a base terminal. A feedback part includes capacitance elements for feedback, and feedbacks a frequency signal outputted from an emitter terminal of the transistor to the transistor via the base terminal. Besides, base bleeder resistances for adjusting a bias voltage to be applied to the base terminal and the transistor are formed in a common integrated circuit, and an emitter resistance is provided outside the integrated circuit as a resistance element being a different body in order to adjust an operating point of the transistor.Type: ApplicationFiled: August 4, 2011Publication date: February 16, 2012Applicant: Nihon Dempa Kohyo Co., Ltd.Inventor: Junichiro Yamakawa
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Patent number: 8111110Abstract: A low-noise voltage controlled oscillator is provided, to improve a phase noise characteristic and widen a frequency variable range. The low-noise voltage controlled oscillator is configured so that an oscillation element and a capacitor 2 are connected in series between a collector C and an emitter E of a transistor 1, capacitors 3 and 4 are connected in series between the collector C and the emitter E, an electrical potential between the capacitors 3 and 4 is applied to a base B of the transistor 1; a one-port circuit 6 is provided between the collector C and the capacitor 4; and a capacitor for correction 5 is connected in parallel with the capacitors 3 and 4. The one-port circuit 6 includes a tuned circuit provided with a variable capacitor adjusting a capacity thereof smaller and an inductor adjusting a value of inductance larger so as to set a value of impedance relatively large.Type: GrantFiled: September 22, 2009Date of Patent: February 7, 2012Assignee: Nihon Dempa Kogyo Co., LtdInventors: Junichiro Yamakawa, Kazuo Akaike, Takashi Nakaoka, Mikio Takano, Yuichiro Arai
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Patent number: 7924106Abstract: To provide an oscillation module which is able to improve an input level by passing signals in a main signal band while removing near noise and far noise. An oscillation module is provided with an OCXO, an amplifier, and a noise elimination filter. The noise elimination filter includes: a BPF passing a signal in the main signal band and eliminating far noise with respect to the main signal band; an L-BEF eliminating near noise in a low frequency band with respect to the main signal band; and an H-BEF eliminating near noise in a high frequency band with respect to the main signal band. Each filter is configured with a crystal filter.Type: GrantFiled: December 23, 2008Date of Patent: April 12, 2011Assignee: Nihon Dempa Kogyo Co., LtdInventors: Naoto Inouchi, Kazuo Akaike, Junichiro Yamakawa, Masazumi Kubota
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Publication number: 20110080223Abstract: There is provided a voltage controlled oscillator that is compact and can be manufactured at low cost. The voltage controlled oscillator is structured to include: a resonance part including a variable capacitance element and an inductance element, the variable capacitance element having a capacitance that varies according to a control voltage for frequency control input from an external part, and a series resonant frequency of the resonance part being adjusted according to the capacitance; an amplifying part amplifying a frequency signal from the resonance part; and a feedback part including a capacitance element for feedback and feeding the frequency signal amplified by the amplifying part back to the resonance part to form an oscillation loop together with the amplifying part and the resonance part, wherein the amplifying part is provided in an integrated circuit chip, and the resonance part and the capacitance element for feedback are formed as circuit components separate from the integrated circuit chip.Type: ApplicationFiled: September 29, 2010Publication date: April 7, 2011Applicant: NIHON DEMPA KOGYO CO., LTD.Inventors: Junichiro Yamakawa, Kazuo Akaike, Mikio Takano, Hiroshi Hoshigami, Kenji Kawahata, Kietsu Saito, Yasushi Yamamoto, Tatsunori Onzuka, Toshimasa Tsuda, Susumu Yoshimoto
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Publication number: 20110080222Abstract: There is provided a voltage controlled oscillator using a Colpitts circuit capable of suppressing deterioration (decrease) in variable range (adjustable range) of an output frequency due to the influence of an inductance component on a conductive line, which connects a connection point between two capacitors of a feedback part and an emitter of a transistor. In a VCO using a Colpitts circuit, with respect to capacitors 22, 23 of a feedback part 2, a first feedback capacitance element (capacitor) 22 is disposed so as to directly couple a terminal for base (connection part 7) and a terminal for emitter on a base substrate 5, to which a terminal part 8 (T1) extending from a base of a transistor 21 and a terminal part 8 (T2) extending from an emitter of the transistor 21 are fitted, respectively, and a second feedback capacitance element (capacitor) 23 is disposed so as to directly couple the terminal for emitter and the terminal for grounding (ground electrode 51).Type: ApplicationFiled: September 28, 2010Publication date: April 7, 2011Applicant: NIHON DEMPA KOGYO CO., LTD.Inventors: Tatsunori Onzuka, Junichiro Yamakawa, Toshimasa Tsuda, Kenji Kawahata, Hiroshi Hoshigami
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Publication number: 20110080226Abstract: To provide a voltage controlled oscillator having small size and capable of obtaining a low phase noise characteristic over a large span of adjustable range of frequency. A quartz crystal having a characteristic (dielectric loss tangent: tan ?) better than that of fluorocarbon resin, LTCC or the like conventionally used as a substrate of a resonance part 1, and on which a fine pattern of metal film can be formed through a photolithography method, is used as a quartz-crystal substrate 10, and a conductive line is formed on the quartz-crystal substrate 10 to form an inductance element 11 in the resonance part 1. Accordingly, since the resonance part 1 having a high Q value can be formed, it is possible to obtain a voltage controlled oscillator having small size and low loss over a wide frequency band.Type: ApplicationFiled: September 28, 2010Publication date: April 7, 2011Applicant: NIHON DEMPA KOGYO CO., LTD.Inventors: Junichiro Yamakawa, Kazuo Akaike, Tatsunori Onzuka, Toshimasa Tsuda, Mikio Takano, Yasushi Yamamoto, Susumu Yoshimoto
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Publication number: 20100266451Abstract: To shorten the time required for an oscillation frequency to stabilize in a sensing device sensing a substance to be sensed by using the fact that a natural frequency of a piezoelectric resonator changes when the substance to be sensed is adsorbed by an adsorption layer formed on the piezoelectric resonator. A sensing device includes: an oscillator circuit 4 oscillating a quartz-crystal resonator 12; and an intense excitation circuit that is formed by the oscillator circuit 4 including a series circuit of a resistor 52 and a third transistor 53 of PNP type and that intensely excites the quartz-crystal resonator 12 connected to the oscillator circuit 4 for a period of time preset by a one-shot circuit 22 by supplying the quartz-crystal resonator 12 with high power equal to or more than twice regular power supplied at the time of the measurement of the substance to be sensed, to stabilize the oscillation of the quartz-crystal resonator 12.Type: ApplicationFiled: April 14, 2010Publication date: October 21, 2010Applicant: NIHON DEMPA KOGYO CO., LTD.Inventors: Tomoya Yorita, Junichiro Yamakawa, Shigenori Watanabe, Mitsuaki Koyama
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Publication number: 20100073101Abstract: A low-noise voltage controlled oscillator is provided, to improve a phase noise characteristic and widen a frequency variable range. The low-noise voltage controlled oscillator is configured so that an oscillation element and a capacitor 2 are connected in series between a collector C and an emitter E of a transistor 1, capacitors 3 and 4 are connected in series between the collector C and the emitter E, an electrical potential between the capacitors 3 and 4 is applied to a base B of the transistor 1; a one-port circuit 6 is provided between the collector C and the capacitor 4; and a capacitor for correction 5 is connected in parallel with the capacitors 3 and 4. The one-port circuit 6 includes a tuned circuit provided with a variable capacitor adjusting a capacity thereof smaller and an inductor adjusting a value of inductance larger so as to set a value of impedance relatively large.Type: ApplicationFiled: September 22, 2009Publication date: March 25, 2010Inventors: Junichiro Yamakawa, Kazuo Akaike, Takashi Nakaoka, Mikio Takano, Yuichiro Arai
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Publication number: 20090288488Abstract: To provide a piezoelectric sensor in which a first electrode for measurement and a second electrode for reference are provided apart from each other on one surface side of a piezoelectric piece and a common electrode is provided on the other surface side so as to face the first and second electrodes, and which achieves highly reliable oscillation by reducing the influence of electrical coupling between the first electrode and the second electrode. A piezoelectric sensor includes: a first electrode for measurement and a second electrode for reference provided apart from each other on one surface side of a piezoelectric piece; a common electrode provided on the other surface side of the piezoelectric piece commonly for the first electrode and the second electrode to face the first electrode and the second electrode; and an adsorption layer formed on an area, of the common electrode, to which the first electrode is projected, to adsorb a substance to be sensed.Type: ApplicationFiled: May 19, 2009Publication date: November 26, 2009Inventors: Junichiro Yamakawa, Kazuo Akaike, Takeru Mutoh, Hiroyuki Kukita
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Publication number: 20090174488Abstract: To provide an oscillation module which is able to improve an input level by passing signals in a main signal band while removing near noise and far noise. An oscillation module is provided with an OCXO, an amplifier, and a noise elimination filter. The noise elimination filter includes: a BPF passing a signal in the main signal band and eliminating far noise with respect to the main signal band; an L-BEF eliminating near noise in a low frequency band with respect to the main signal band; and an H-BEF eliminating near noise in a high frequency band with respect to the main signal band. Each filter is configured with a crystal filter.Type: ApplicationFiled: December 23, 2008Publication date: July 9, 2009Inventors: Naoto Inouchi, Kazuo Akaike, Junichiro Yamakawa, Masazumi Kubota
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Patent number: 7375588Abstract: A transmission amplifier for amplifying a signal to be transmitted includes an amplifying unit that is warmed efficiently when the temperature is low. In a constitution in which an amplifying unit amplifies a signal, a temperature detecting means detects temperature. Amplifying-unit-self-heating-facilitation control means perform control for facilitating self-heating by the amplifying unit when temperature detected by the temperature detecting means is lower than a predetermined threshold value, or equal to or lower than the predetermined threshold value. The amplifying-unit-self-heating-facilitation control means perform, for example, bias control for the amplifying unit as the control for facilitating self-heating by the amplifying unit.Type: GrantFiled: March 23, 2004Date of Patent: May 20, 2008Assignee: Hitachi Kokusai Electric Inc.Inventors: Junichiro Yamakawa, Junya Dosaka
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Publication number: 20060214730Abstract: In a transmission amplifier for amplifying a signal to be transmitted, an amplifying unit is warmed efficiently when temperature is low. In a constitution in which an amplifying unit 1 amplifies a signal, temperature detecting means 4 detects temperature. Amplifying-unit-self-heating-facilitation control means 2 and 5 perform control for facilitating self-heating by the amplifying unit 1 when temperature detected by the temperature detecting means 4 is lower than a predetermined threshold value or equal to or lower than the predetermined threshold value. The amplifying-unit-self-heating-facilitation control means 2 and 5 perform, for example, bias control for the amplifying unit 1 as the control for facilitating self-heating by the amplifying unit 1.Type: ApplicationFiled: March 23, 2004Publication date: September 28, 2006Inventors: Junichiro Yamakawa, Junya Dosaka
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Patent number: 6933327Abstract: A dental polymerizable and curable composition that can be used as a dental composite restorative featuring excellent handling property at the time of filling, a small contraction upon polymerization, a high bending strength, excellent surface smoothness and wear resistance, and a very good matching of color tone to the natural tooth after restored.Type: GrantFiled: August 16, 2001Date of Patent: August 23, 2005Assignee: Tokuyama CorporationInventors: Junichiro Yamakawa, Hideki Kazama