Patents by Inventor Akihiro Fukuzawa

Akihiro Fukuzawa 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: 20170104473
    Abstract: A oscillator includes a substrate having a first surface and a second surface, a first wiring layer and a second wiring layer disposed respectively on the first and second surfaces, and a plurality of through holes electrically connecting the first and second wiring layers to each other, a resonator disposed above the first surface of the substrate, and having a resonator element, a pair of electrodes sandwiching the resonator element, and a pair of terminals adapted to electrically connect the pair of electrodes to the first electrode layer, and at least one semiconductor device disposed on the second surface of the substrate, adapted to generate an oscillation signal, and having first and second terminals electrically connected respectively to the pair of terminals of the resonator via the second wiring layer and the first wiring layer, and a third terminal supplied with a digital control signal, wherein a distance between each of the first and second terminals and the pair of terminals of the resonator is
    Type: Application
    Filed: October 6, 2016
    Publication date: April 13, 2017
    Inventor: Akihiro FUKUZAWA
  • Patent number: 9559718
    Abstract: A D/A conversion circuit includes a plurality of resistors that are formed on a semiconductor substrate and that are connected in series to each other and a plurality of switches that are connected to the plurality of resistors, respectively, in which the plurality of resistors are configured using resistive element and a plurality of contacts that are provided to the resistive element, in which the plurality of switches are arranged side by side along a first direction when the semiconductor substrate is viewed from above, in which distances in the first direction between the plurality of contacts are equal to each other, and in which lengths in a second direction that is perpendicular to the first direction, of the plurality of resistors are unequal to each other.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: January 31, 2017
    Assignee: Seiko Epson Corporation
    Inventor: Akihiro Fukuzawa
  • Patent number: 9537448
    Abstract: An oscillator includes: an oscillation circuit whose oscillation frequency changes based on a voltage that is applied to a variable capacitance element; and a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, in which the voltage that is generated by the voltage generation unit changes nonlinearly with respect to a change in the control signal such that a change in the oscillation frequency with respect to the change in the control signal is adjusted to come close to be linear.
    Type: Grant
    Filed: February 2, 2016
    Date of Patent: January 3, 2017
    Assignee: Seiko Epson Corporation
    Inventor: Akihiro Fukuzawa
  • Patent number: 9438167
    Abstract: An oscillation circuit includes: an oscillation unit which includes a first terminal and a second terminal connected to a resonator, a third terminal, a fourth terminal to which at least one of a power supply potential and a signal for inspecting the resonator is applied, a first switching unit which switches modes of electrical connection between the first terminal and the third terminal, and a second switching unit which switches modes of electrical connection between the second terminal and the fourth terminal.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: September 6, 2016
    Assignee: Seiko Epson Corporation
    Inventors: Yosuke Itasaka, Masayuki Ishikawa, Takehiro Yamamoto, Akihiro Fukuzawa
  • Publication number: 20160226447
    Abstract: An oscillator includes an input terminal, an oscillation circuit section configured to cause a resonator to resonate to output an oscillator signal, a digital input section to which a signal for controlling an oscillation frequency of the oscillation circuit section is input via the input terminal, and a first bias circuit section including a constant current source configured to supply a reference current to the digital input section.
    Type: Application
    Filed: February 3, 2016
    Publication date: August 4, 2016
    Inventor: Akihiro FUKUZAWA
  • Publication number: 20160226510
    Abstract: A D/A conversion circuit includes a plurality of resistors that are formed on a semiconductor substrate and that are connected in series to each other and a plurality of switches that are connected to the plurality of resistors, respectively, in which the plurality of resistors are configured using resistive element and a plurality of contacts that are provided to the resistive element, in which the plurality of switches are arranged side by side along a first direction when the semiconductor substrate is viewed from above, in which distances in the first direction between the plurality of contacts are equal to each other, and in which lengths in a second direction that is perpendicular to the first direction, of the plurality of resistors are unequal to each other.
    Type: Application
    Filed: February 2, 2016
    Publication date: August 4, 2016
    Inventor: Akihiro FUKUZAWA
  • Publication number: 20160226446
    Abstract: An oscillator includes: an oscillation circuit whose oscillation frequency changes based on a voltage that is applied to a variable capacitance element; and a voltage generation unit that generates the voltage which is applied to the variable capacitance element based on a control signal, in which the voltage that is generated by the voltage generation unit changes nonlinearly with respect to a change in the control signal such that a change in the oscillation frequency with respect to the change in the control signal is adjusted to come close to be linear.
    Type: Application
    Filed: February 2, 2016
    Publication date: August 4, 2016
    Inventor: Akihiro FUKUZAWA
  • Publication number: 20160211853
    Abstract: An oscillator includes a control voltage generator that generates a control voltage between a first reference voltage and a second reference voltage with a digital signal, and a voltage controlled oscillation circuit that outputs a signal at a frequency in response to the control voltage. The control voltage generator includes a first D/A conversion circuit of resistor voltage-dividing type that generates a voltage between the first reference voltage and the second reference voltage.
    Type: Application
    Filed: January 13, 2016
    Publication date: July 21, 2016
    Inventor: Akihiro FUKUZAWA
  • Patent number: 9312812
    Abstract: An oscillation circuit includes a terminal XO which is connected to one end of a resonator, a terminal XI which is connected to the other end of the resonator, an oscillation unit which is electrically connected to the terminal XO and the terminal XI, a control voltage generation circuit, and a switch. The oscillation unit includes a variable capacitive element having one end which is connected to the terminal XO or the terminal XI. The switch controls electrical connection between the other end of the variable capacitive element and an output terminal of the control voltage generation circuit.
    Type: Grant
    Filed: October 29, 2014
    Date of Patent: April 12, 2016
    Assignee: Seiko Epson Corporation
    Inventors: Yosuke Itasaka, Masayuki Ishikawa, Takehiro Yamamoto, Akihiro Fukuzawa
  • Patent number: 9246469
    Abstract: A manufacturing method of an oscillator is a manufacturing method of an oscillator which includes a vibrator and a semiconductor circuit device including an oscillation part connected to the vibrator and a control part to switch an operation mode between a normal mode in which the oscillation part performs an oscillation operation and an inspection mode in which characteristics of the vibrator are inspected, and the manufacturing method includes preparing the semiconductor circuit device in which the operation mode is set to the inspection mode, connecting the semiconductor circuit device and the vibrator electrically, and inspecting the characteristics of the vibrator which is in a state electrically connected to the semiconductor circuit device.
    Type: Grant
    Filed: November 10, 2014
    Date of Patent: January 26, 2016
    Assignee: Seiko Epson Corporation
    Inventors: Masayuki Ishikawa, Yosuke Itasaka, Takehiro Yamamoto, Akihiro Fukuzawa
  • Publication number: 20150180443
    Abstract: An IC for heating includes a semiconductor substrate on which a diffusion layer is formed; a first pad and a first via that apply a power voltage to the diffusion layer; and a second pad and a second via that apply a ground voltage to the diffusion layer. The vias overlap with an area on which the diffusion layer is formed in a plan view, the first pad overlaps with the first via in a plan view, and the second pad overlaps with the second via in a plan view. The current flowing through the first pad and the first via, the second pad and the second via, and the diffusion layer flows between an upper surface of the first pad and a lower surface of the first via, and a lower surface of the second via and an upper surface of the second pad.
    Type: Application
    Filed: December 16, 2014
    Publication date: June 25, 2015
    Inventors: Kenji HAYASHI, Akihiro FUKUZAWA
  • Publication number: 20150180444
    Abstract: An IC for heating includes a semiconductor, substrate on which a diffusion layer is formed; a first pad that applies a power source voltage to the diffusion layer; and a second pad that applies a ground voltage to the diffusion layer. A semiconductor substrate includes slits such that the slits intersect a virtual straight line connecting the pads when the semiconductor substrate is seen in a plan view.
    Type: Application
    Filed: December 18, 2014
    Publication date: June 25, 2015
    Inventors: Kenji HAYASHI, Akihiro FUKUZAWA
  • Publication number: 20150130547
    Abstract: A manufacturing method of an oscillator is a manufacturing method of an oscillator which includes a vibrator and a semiconductor circuit device including an oscillation part connected to the vibrator and a control part to switch an operation mode between a normal mode in which the oscillation part performs an oscillation operation and an inspection mode in which characteristics of the vibrator are inspected, and the manufacturing method includes preparing the semiconductor circuit device in which the operation mode is set to the inspection mode, connecting the semiconductor circuit device and the vibrator electrically, and inspecting the characteristics of the vibrator which is in a state electrically connected to the semiconductor circuit device.
    Type: Application
    Filed: November 10, 2014
    Publication date: May 14, 2015
    Inventors: Masayuki ISHIKAWA, Yosuke ITASAKA, Takehiro YAMAMOTO, Akihiro FUKUZAWA
  • Publication number: 20150116045
    Abstract: An oscillation circuit includes a terminal XO, a terminal XI, an oscillation unit, and a voltage generation circuit that generates a first voltage and a second voltage. The oscillation unit includes a variable capacitive element connected to the terminal XO or the terminal XI. In a first mode, a signal having a first amplitude is applied between the terminal XO and the terminal XI, and a first voltage is applied to the other end of the variable capacitive element. In a second mode, a signal having a second amplitude larger than an amplitude of the signal having the first amplitude is applied between the terminal XO and the terminal XI, a second voltage is applied to the other end of the variable capacitive element, and a voltage applied to the both ends of the variable capacitive element is lower than the maximum rated voltage of the variable capacitive element.
    Type: Application
    Filed: October 29, 2014
    Publication date: April 30, 2015
    Inventors: Yosuke ITASAKA, Masayuki ISHIKAWA, Takehiro YAMAMATO, Akihiro FUKUZAWA
  • Publication number: 20150116044
    Abstract: An oscillation circuit includes: an oscillation unit which includes a first terminal and a second terminal connected to a resonator, a third terminal, a fourth terminal to which at least one of a power supply potential and a signal for inspecting the resonator is applied, a first switching unit which switches modes of electrical connection between the first terminal and the third terminal, and a second switching unit which switches modes of electrical connection between the second terminal and the fourth terminal.
    Type: Application
    Filed: October 29, 2014
    Publication date: April 30, 2015
    Inventors: Yosuke ITASAKA, Masayuki ISHIKAWA, Takehiro YAMAMOTO, Akihiro FUKUZAWA
  • Publication number: 20150116043
    Abstract: An oscillation circuit includes a terminal XO which is connected to one end of a resonator, a terminal XI which is connected to the other end of the resonator, an oscillation unit which is electrically connected to the terminal XO and the terminal XI, a control voltage generation circuit, and a switch. The oscillation unit includes a variable capacitive element having one end which is connected to the terminal XO or the terminal XI. The switch controls electrical connection between the other end of the variable capacitive element and an output terminal of the control voltage generation circuit.
    Type: Application
    Filed: October 29, 2014
    Publication date: April 30, 2015
    Inventors: Yosuke ITASAKA, Masayuki ISHIKAWA, Takehiro YAMAMOTO, Akihiro FUKUZAWA
  • Patent number: 8098098
    Abstract: An amplifier circuit includes an amplifier section that includes a P-type differential section, an N-type differential section, and an output section, an offset adjustment section that adjusts an offset of the amplifier section, a first offset adjustment register that stores a first offset adjustment value for the P-type differential section, a second offset adjustment register that stores a second offset adjustment value for the N-type differential section, and a control section that sets the first offset adjustment value in the offset adjustment section in a first operation mode in which the P-type differential section operates, and sets the second offset adjustment value in the offset adjustment section in a second operation mode in which the N-type differential section operates.
    Type: Grant
    Filed: March 29, 2010
    Date of Patent: January 17, 2012
    Assignee: Seiko Epson Corporation
    Inventor: Akihiro Fukuzawa
  • Patent number: 7924202
    Abstract: An integrated circuit device includes an amplifier circuit that includes first to Nth amplifiers that are cascaded and receives an input signal, an A/D converter that performs an A/D conversion process on a signal amplified by the amplifier circuit, first to Nth D/A converters that are provided corresponding to the first to Nth amplifiers and used to perform an offset adjustment of the first to Nth amplifiers, and a control circuit that sets an offset adjustment of the first to Nth amplifiers using the first to Nth D/A converters and a gain adjustment of the first to Nth amplifiers.
    Type: Grant
    Filed: February 20, 2009
    Date of Patent: April 12, 2011
    Assignee: Seiko Epson Corporation
    Inventors: Akihiro Fukuzawa, Satoru Ito, Nobuyuki Imai
  • Patent number: 7870786
    Abstract: A detection device includes a detection circuit and a reference voltage supply circuit. The detection circuit includes an amplifier circuit, a synchronous detection circuit, and a filter section. The reference voltage supply circuit includes a first supply circuit which includes a reference-voltage first-type operational amplifier and supplies an analog reference voltage to the amplifier circuit, and a second supply circuit which includes a reference-voltage second-type operational amplifier and supplies the analog reference voltage to the filter section.
    Type: Grant
    Filed: November 8, 2007
    Date of Patent: January 18, 2011
    Assignee: Seiko Epson Corporation
    Inventor: Akihiro Fukuzawa
  • Patent number: 7859351
    Abstract: An oscillation driver circuit includes a current-voltage converter which converts a current value of an oscillation signal in an oscillation loop into a voltage value, and a comparator which outputs a signal corresponding to the result of comparison between the output signal from the current-voltage converter and a given reference signal. The comparator has an output current limiting function. The oscillation driver circuit causes the vibrator to produce driving vibrations based on the output from the comparator.
    Type: Grant
    Filed: September 7, 2007
    Date of Patent: December 28, 2010
    Assignee: Seiko Epson Corporation
    Inventors: Masahiro Kanai, Eitaro Otsuka, Naoki Yoshida, Akihiro Fukuzawa