Patents by Inventor Toshinari Maeda

Toshinari Maeda 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: 11422511
    Abstract: An electronic watch with a two-coil stepper motor including: a magnetized rotor; a stator including: first and second stator magnetic-pole portions, which are formed so as to oppose to each other through the rotor; and a third stator magnetic-pole portion, which is formed between the first stator magnetic-pole portion and the second stator magnetic-pole portion so as to face the rotor; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; and a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; and a high-speed drive pulse generation circuit configured to output a drive pulse for driving the rotor to the coil A or the coil B, and wherein the rotor is rotationally driven in increments of 360° due to a drive pulse train formed of the plurality of drive pulses.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: August 23, 2022
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Yu Takyoh, Toshiaki Fukushima, Toshinari Maeda, Daisuke Iri, Daisuke Matsuoh, Masatoshi Nishida
  • Patent number: 11303225
    Abstract: Provided is a small-sized electrostatic motor having a rotor capable of starting reliably to rotate forward. The electrostatic motor includes a rotor rotatable around a rotating shaft, charged portions formed radially around the rotating shaft on upper and lower surfaces of the rotor, first and second stators disposed to sandwich the rotor therebetween, and first sets and second sets of fixed electrodes respectively formed radially around the rotating shaft on the surfaces of the first and second stators facing the rotor and selectively energized according to drive pulses to rotate the rotor by electrostatic force generated between the charged portions and the fixed electrodes. The average number of sets of fixed electrodes simultaneously energized in one cycle of the drive pulses out of the first sets and second sets of fixed electrodes is equal to the average of the numbers of first sets and second sets of fixed electrodes.
    Type: Grant
    Filed: March 22, 2018
    Date of Patent: April 12, 2022
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Toshinari Maeda, Akira Izumi
  • Publication number: 20220026853
    Abstract: Provided is a wristwatch, including: an exterior case including a back cover; a moisture absorbent sheet to be provided on an inner surface of the back cover; and a holding sheet configured to adhere to the inner surface of the back cover around the moisture absorbent sheet and cover an edge of the moisture absorbent sheet, to thereby hold the moisture absorbent sheet such that the moisture absorbent sheet is allowed to absorb moisture.
    Type: Application
    Filed: October 18, 2019
    Publication date: January 27, 2022
    Inventors: Masato TAKAHASHI, Toshinari MAEDA, Makoto WATANABE, Yudai HOSHI
  • Patent number: 11101748
    Abstract: Provided is a method of manufacturing an electrostatic induction transducer, the method including: providing a conductive substrate; providing a first electret material film on a first surface of the conductive substrate; providing a second electret material film on a second surface of the conductive substrate; forming a through hole that penetrates the conductive substrate, the first electret material film, and the second electret material film; mounting a supported member being conductive to the conductive substrate while allowing the conductive substrate to move in an in-plane direction; and applying charges to the first electret material film and the second electret material film by a charging process.
    Type: Grant
    Filed: October 29, 2019
    Date of Patent: August 24, 2021
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Toshinari Maeda, Makoto Watanabe, Yasuo Kitajima, Izumi Yamamoto
  • Patent number: 11086273
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including: a rotor; a stator including first, second, and third stator magnetic-pole portions; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; a drive pulse generation circuit configured to output a drive pulse; a detection pulse generation circuit configured to output a detection pulse for detecting counter-electromotive currents generated in the coil A and the coil B; and a rotation detection circuit configured to receive a detection signal generated due to the detection pulse as input to determine whether or not the rotor has rotated.
    Type: Grant
    Filed: September 24, 2019
    Date of Patent: August 10, 2021
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Yu Takyoh, Toshiaki Fukushima, Toshinari Maeda, Daisuke Iri, Daisuke Matsuoh
  • Publication number: 20200333749
    Abstract: An electronic watch with a two-coil stepper motor including: a magnetized rotor; a stator including: first and second stator magnetic-pole portions, which are formed so as to oppose to each other through the rotor; and a third stator magnetic-pole portion, which is formed between the first stator magnetic-pole portion and the second stator magnetic-pole portion so as to face the rotor; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; and a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; and a high-speed drive pulse generation circuit configured to output a drive pulse for driving the rotor to the coil A or the coil B, and wherein the rotor is rotationally driven in increments of 360° due to a drive pulse train formed of the plurality of drive pulses.
    Type: Application
    Filed: June 29, 2020
    Publication date: October 22, 2020
    Inventors: Yu TAKYOH, Toshiaki FUKUSHIMA, Toshinari MAEDA, Daisuke IRI, Daisuke MATSUOH, Masatoshi NISHIDA
  • Patent number: 10754299
    Abstract: An electronic watch with a two-coil stepper motor including: a magnetized rotor; a stator including: first and second stator magnetic-pole portions, which are formed so as to oppose to each other through the rotor; and a third stator magnetic-pole portion, which is formed between the first stator magnetic-pole portion and the second stator magnetic-pole portion so as to face the rotor; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; and a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; and a high-speed drive pulse generation circuit configured to output a drive pulse for driving the rotor to the coil A or the coil B, and wherein the rotor is rotationally driven in increments of 360° due to a drive pulse train formed of the plurality of drive pulses.
    Type: Grant
    Filed: February 15, 2017
    Date of Patent: August 25, 2020
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Yu Takyoh, Toshiaki Fukushima, Toshinari Maeda, Daisuke Iri, Daisuke Matsuoh, Masatoshi Nishida
  • Publication number: 20200144937
    Abstract: Provided is a method of manufacturing an electrostatic induction transducer, the method including: providing a conductive substrate; providing a first electret material film on a first surface of the conductive substrate; providing a second electret material film on a second surface of the conductive substrate; forming a through hole that penetrates the conductive substrate, the first electret material film, and the second electret material film; mounting a supported member being conductive to the conductive substrate while allowing the conductive substrate to move in an in-plane direction; and applying charges to the first electret material film and the second electret material film by a charging process.
    Type: Application
    Filed: October 29, 2019
    Publication date: May 7, 2020
    Inventors: Toshinari MAEDA, Makoto WATANABE, Yasuo KITAJIMA, Izumi YAMAMOTO
  • Publication number: 20200081404
    Abstract: An electronic watch includes a power source, an electrostatic motor including a rotor in which a plurality of electret films are arranged in a rotational direction and a plurality of fixed electrodes arranged in the rotational direction at positions facing the rotor, a hand rotating in conjunction with the rotation of the rotor, and a motor control circuit controlling the electrostatic motor. The motor control circuit selectively executes a hand movement mode for rotating the hand and a stop mode for keeping the hand stationary. In the stop mode, the motor control circuit keeps the rotor stationary through electrostatic forces exerted on the electret films from the fixed electrodes with the polarities of the fixed electrodes maintained.
    Type: Application
    Filed: September 6, 2019
    Publication date: March 12, 2020
    Applicant: CITIZEN WATCH CO., LTD.
    Inventors: Toshinari MAEDA, Shogo KIMURA
  • Publication number: 20200076327
    Abstract: Provided is a small-sized electrostatic motor having a rotor capable of starting reliably to rotate forward. The electrostatic motor includes a rotor rotatable around a rotating shaft, charged portions formed radially around the rotating shaft on upper and lower surfaces of the rotor, first and second stators disposed to sandwich the rotor therebetween, and first sets and second sets of fixed electrodes respectively formed radially around the rotating shaft on the surfaces of the first and second stators facing the rotor and selectively energized according to drive pulses to rotate the rotor by electrostatic force generated between the charged portions and the fixed electrodes. The average number of sets of fixed electrodes simultaneously energized in one cycle of the drive pulses out of the first sets and second sets of fixed electrodes is equal to the average of the numbers of first sets and second sets of fixed electrodes.
    Type: Application
    Filed: March 22, 2018
    Publication date: March 5, 2020
    Inventors: Toshinari MAEDA, Akira IZUMI
  • Patent number: 10545459
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including: a rotor; a stator including first, second, and third stator magnetic-pole portions; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; a drive pulse generation circuit configured to output a drive pulse; a detection pulse generation circuit configured to output a detection pulse for detecting counter-electromotive currents generated in the coil A and the coil B; and a rotation detection circuit configured to receive a detection signal generated due to the detection pulse as input to determine whether or not the rotor has rotated.
    Type: Grant
    Filed: September 9, 2016
    Date of Patent: January 28, 2020
    Assignee: Citizen Watch Co., LTD.
    Inventors: Yu Takyoh, Toshiaki Fukushima, Toshinari Maeda, Daisuke Iri, Daisuke Matsuoh
  • Publication number: 20200019124
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including: a rotor; a stator including first, second, and third stator magnetic-pole portions; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; a drive pulse generation circuit configured to output a drive pulse; a detection pulse generation circuit configured to output a detection pulse for detecting counter-electromotive currents generated in the coil A and the coil B; and a rotation detection circuit configured to receive a detection signal generated due to the detection pulse as input to determine whether or not the rotor has rotated.
    Type: Application
    Filed: September 24, 2019
    Publication date: January 16, 2020
    Inventors: Yu TAKYOH, Toshiaki FUKUSHIMA, Toshinari MAEDA, Daisuke IRI, Daisuke MATSUOH
  • Publication number: 20190041804
    Abstract: An electronic watch with a two-coil stepper motor including: a magnetized rotor; a stator including: first and second stator magnetic-pole portions, which are formed so as to oppose to each other through the rotor; and a third stator magnetic-pole portion, which is formed between the first stator magnetic-pole portion and the second stator magnetic-pole portion so as to face the rotor; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; and a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; and a high-speed drive pulse generation circuit configured to output a drive pulse for driving the rotor to the coil A or the coil B, and wherein the rotor is rotationally driven in increments of 360° due to a drive pulse train formed of the plurality of drive pulses.
    Type: Application
    Filed: February 15, 2017
    Publication date: February 7, 2019
    Inventors: Yu TAKYOH, Toshiaki FUKUSHIMA, Toshinari MAEDA, Daisuke IRI, Daisuke MATSUOH, Masatoshi NISHIDA
  • Patent number: 10197972
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including a rotor that is magnetized to an N-pole and an S-pole, first, second, and third stator magnetic-pole portions, a coil A, and a coil B. The drive circuit includes a drive pulse generation circuit configured to output a drive pulse (SP) for driving the coil A and the coil B, a detection pulse generation circuit configured to output a detection pulse (CP) to the coil A and the coil B in order to detect counter-electromotive currents generated in the coil A and the coil B along with a movement of the rotor after the rotor is driven based on the drive pulse, and a detection circuit configured to receive a detection signal (CS) generated based on the detection pulse as input, to thereby detect the movement of the rotor. At least one of the detection pulse to the coil A or the detection pulse to the coil B is output.
    Type: Grant
    Filed: December 24, 2015
    Date of Patent: February 5, 2019
    Assignee: CITIZEN WATCH CO., LTD.
    Inventors: Toshiaki Fukushima, Toshinari Maeda, Yu Takyoh, Daisuke Iri
  • Publication number: 20180246471
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including: a rotor; a stator including first, second, and third stator magnetic-pole portions; a coil A to be magnetically coupled to the first stator magnetic-pole portion and the third stator magnetic-pole portion; a coil B to be magnetically coupled to the second stator magnetic-pole portion and the third stator magnetic-pole portion; a drive pulse generation circuit configured to output a drive pulse; a detection pulse generation circuit configured to output a detection pulse for detecting counter-electromotive currents generated in the coil A and the coil B; and a rotation detection circuit configured to receive a detection signal generated due to the detection pulse as input to determine whether or not the rotor has rotated.
    Type: Application
    Filed: September 9, 2016
    Publication date: August 30, 2018
    Inventors: Yu TAKYOH, Toshiaki FUKUSHIMA, Toshinari MAEDA, Daisuke IRI, Daisuke MATSUOH
  • Publication number: 20170357216
    Abstract: Provided is a drive circuit for a two-coil stepper motor, including a rotor that is magnetized to an N-pole and an S-pole, first, second, and third stator magnetic-pole portions, a coil A, and a coil B. The drive circuit includes a drive pulse generation circuit configured to output a drive pulse (SP) for driving the coil A and the coil B, a detection pulse generation circuit configured to output a detection pulse (CP) to the coil A and the coil B in order to detect counter-electromotive currents generated in the coil A and the coil B along with a movement of the rotor after the rotor is driven based on the drive pulse, and a detection circuit configured to receive a detection signal (CS) generated based on the detection pulse as input, to thereby detect the movement of the rotor. At least one of the detection pulse to the coil A or the detection pulse to the coil B is output.
    Type: Application
    Filed: December 24, 2015
    Publication date: December 14, 2017
    Inventors: Toshiaki FUKUSHIMA, Toshinari MAEDA, Yu TAKYOH, Daisuke IRI
  • Patent number: 9529330
    Abstract: An oscillating stepping motor can reduce a required rotational angle of a rotor to drive a star wheel, reduce idle driving, cut the loss of energy required for the driving, reduce power consumption even in high-frequency driving, and stably operate. Two star wheels are located so that the tooth tips thereof are not engaged with each other. A rotor shaft includes a rotor pinion having two feed teeth at a certain aperture angle. One of the feed teeth feeds one of the driving wheels by oscillation of the rotor in one direction and the other of the feed teeth feeds the other of the driving wheels by the oscillation of the rotor in the other. The rotor then oscillates within a certain angle range, thereby sequentially rotating output gears in a certain direction by a certain angle.
    Type: Grant
    Filed: September 1, 2011
    Date of Patent: December 27, 2016
    Assignee: CITIZEN HOLDINGS CO., LTD.
    Inventors: Toshiaki Fukushima, Akira Shiota, Toshinari Maeda
  • Patent number: 8841875
    Abstract: Provided is an electronic watch capable of, even if an indicating hand having a large moment of inertia is used, accurately determining success and failure of rotation. The electronic watch detects rotation by using a first detection mode determination circuit (12) and a second detection mode determination circuit (13). In the electronic watch, a timing counter (14) for measuring a time after an output of a normal drive pulse is followed by a detection pulse selection circuit (151) provided as changing means for changing a width or a frequency of a detection pulse in accordance with an output time of the detection pulse. The detection pulse detects the rotation and simultaneously serves as an electromagnetic brake for a rotor (10). The electromagnetic brake for the rotor (10) is controlled by changing the width or the frequency of the detection pulse in a predetermined period, thereby achieving an accurate rotation detection.
    Type: Grant
    Filed: October 6, 2010
    Date of Patent: September 23, 2014
    Assignees: Citizen Holdings Co., Ltd., Citizen Watch Co., Ltd
    Inventors: Yu Takyo, Toshiaki Fukushima, Akira Shiota, Toshinari Maeda, Nobuaki Suzuki
  • Publication number: 20130162060
    Abstract: An oscillating stepping motor can reduce a required rotational angle of a rotor to drive a star wheel, reduce idle driving, cut the loss of energy required for the driving, reduce power consumption even in high-frequency driving, and stably operate. Two star wheels are located so that the tooth tips thereof are not engaged with each other. A rotor shaft includes a rotor pinion having two feed teeth at a certain aperture angle. One of the feed teeth feeds one of the driving wheels by oscillation of the rotor in one direction and the other of the feed teeth feeds the other of the driving wheels by the oscillation of the rotor in the other. The rotor then oscillates within a certain angle range, thereby sequentially rotating output gears in a certain direction by a certain angle.
    Type: Application
    Filed: September 1, 2011
    Publication date: June 27, 2013
    Inventors: Toshiaki Fukushima, Akira Shiota, Toshinari Maeda
  • Publication number: 20120204640
    Abstract: Provided is an electronic watch capable of, even if an indicating hand having a large moment of inertia is used, accurately determining success and failure of rotation. The electronic watch detects rotation by using a first detection mode determination circuit (12) and a second detection mode determination circuit (13). In the electronic watch, a timing counter (14) for measuring a time after an output of a normal drive pulse is followed by a detection pulse selection circuit (151) provided as changing means for changing a width or a frequency of a detection pulse in accordance with an output time of the detection pulse. The detection pulse detects the rotation and simultaneously serves as an electromagnetic brake for a rotor (10). The electromagnetic brake for the rotor (10) is controlled by changing the width or the frequency of the detection pulse in a predetermined period, thereby achieving an accurate rotation detection.
    Type: Application
    Filed: October 6, 2010
    Publication date: August 16, 2012
    Applicants: CITIZEN WATCH CO., LTD, CITIZEN HOLDINGS CO., LTD.
    Inventors: Yu Takyo, Toshiaki Fukushima, Akira Shiota, Toshinari Maeda, Nobuaki Suzuki