Patents by Inventor Taku Okamoto

Taku Okamoto 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: 11964710
    Abstract: A crawler type traveling body includes a drive wheel, an in-wheel motor incorporated in the drive wheel, a plurality of rotating wheels disposed below the drive wheel, a crawler, and a tensioner. The crawler is wound around the drive wheel and the rotating wheels and configured to be rotated by the drive wheel. The tensioner is coupled to a drive shaft of the in-wheel motor and configured to press the drive wheel against the crawler and apply tension to the crawler.
    Type: Grant
    Filed: January 25, 2021
    Date of Patent: April 23, 2024
    Assignee: Ricoh Company, Ltd.
    Inventors: Eichi Koizumi, Hiroshi Shimura, Ryota Yamashina, Taku Kitahara, Hiroshi Okamoto
  • Publication number: 20230324329
    Abstract: A casing of a gas sensor having a reference gas space therein includes: an outer tube into which an end portion of a sensor element protrudes; and a seal member fit into an end portion of the outer tube to seal the reference gas space, the sensor element includes: a first electrode lead portion including a first electrode lead to electrically connect an outside and at least one inner electrode and a first lead insulating layer covering the first electrode lead; and a second electrode lead portion including a second electrode lead that can electrically connect the outside and a measurement electrode and a second lead insulating layer covering the second electrode lead, and A/B < 1.00, where A (cm-1) is diffusion resistance of the first electrode lead portion, B (cm-1) is diffusion resistance of the second electrode lead portion.
    Type: Application
    Filed: March 17, 2023
    Publication date: October 12, 2023
    Inventors: Yusuke WATANABE, Taku OKAMOTO
  • Publication number: 20230324327
    Abstract: A controller of a gas sensor includes: a concentration identification part identifying a concentration of a predetermined gas component based on a measurement pump current flowing between a measurement electrode and an out-of-space pump electrode in accordance with the concentration of the predetermined gas component due to application of a predetermined pump voltage; and a correction processing part correcting the concentration of the predetermined gas component identified by the concentration identification part, the correction processing part corrects the concentration of the predetermined gas component based on a correlation identified in advance between an offset current value as a magnitude of the measurement pump current when a measurement gas not containing the predetermined gas component flows or a normalized value of the offset current value and output fluctuations of the measurement pump current at startup of the gas sensor.
    Type: Application
    Filed: January 26, 2023
    Publication date: October 12, 2023
    Inventors: Yusuke WATANABE, Taku OKAMOTO
  • Publication number: 20230314367
    Abstract: A sensor element includes first to third chambers communicating sequentially from a gas inlet, voltages are intermittently applied across inner electrodes facing the respective chambers and a reference pump electrode to perform pumping of oxygen between a measurement gas and the reference pump electrode being in contact with a reference gas, thereby to reduce H2O and CO2 in the measurement gas into H2 and CO in the first chamber, to oxidize H2 into H2O in the second chamber, to oxidize CO into CO2 in the third chamber, and to identify a concentration of H2O and a concentration of CO2 based on a pumping-in current at the time when electromotive force between an inner electrode and the reference pump electrode during non-application of a voltage is maintained at a target value.
    Type: Application
    Filed: March 21, 2023
    Publication date: October 5, 2023
    Inventors: Yuichiro KONDO, Taku OKAMOTO
  • Publication number: 20230296553
    Abstract: A casing of a gas sensor having a reference gas space therein includes: an outer tube into which an end portion of a sensor element protrudes; and a seal member fit into an end portion of the outer tube to seal the reference gas space, the sensor element includes: a first electrode lead portion including a first electrode lead to electrically connect an outside and at least one out-of-space pump electrode and a first lead insulating layer covering the first electrode lead; and a second electrode lead portion including a second electrode lead that can electrically connect the outside and a measurement electrode and a second lead insulating layer covering the second electrode lead, and A/B<1.00, where A (cm?1) is diffusion resistance of the first electrode lead portion, B (cm?1) is diffusion resistance of the second electrode lead portion.
    Type: Application
    Filed: March 14, 2023
    Publication date: September 21, 2023
    Inventors: Yusuke WATANABE, Taku OKAMOTO
  • Patent number: 11680926
    Abstract: A gas sensor includes a sensor element including an element body, a first electrode, a second electrode, and a heater; a voltage acquisition section that acquires a voltage between the first electrode and the second electrode; a heater power supply; an external common lead that serves as both at least part of an electric circuit used to acquire the voltage by providing electrical continuity between the first electrode and the voltage acquisition section and at least part of an electric circuit used to supply an electric power from the heater power supply to the heater and that is disposed outside the sensor element; and a correction section that derives a value of a voltage drop in the external common lead in accordance with a heater current and that corrects the voltage acquired by the voltage acquisition section in accordance with the derived value of the voltage drop.
    Type: Grant
    Filed: February 9, 2021
    Date of Patent: June 20, 2023
    Assignee: NGK INSULATORS, LTD.
    Inventors: Taku Okamoto, Yuichiro Kondo, Osamu Nakasone
  • Patent number: 11668670
    Abstract: A gas sensor includes a main pump cell, a storage unit that stores information about a zero point in a first correspondence relationship, where the first correspondence relationship is a linear correspondence relationship between the oxygen concentration in a measurement-object gas and the main pump current, an oxygen-concentration-detecting unit that detects the oxygen concentration in a measurement-object gas, based on a measured value p of the main pump current and the information about the zero point, and a measured-value-obtaining unit that performs a second control process and that obtains a measured value b1 at a measurement point B1 at which a known value of the oxygen concentration and the main pump current are relevant to each other with a measurement timing. The oxygen-concentration-detecting unit makes zero point correction such that a divergence of the zero point from the first correspondence relationship is corrected based on the measured value b1.
    Type: Grant
    Filed: January 7, 2021
    Date of Patent: June 6, 2023
    Assignee: NGK INSULATORS, LTD.
    Inventors: Daichi Ichikawa, Taku Okamoto
  • Publication number: 20220299464
    Abstract: A gas sensor includes a sensor element and a pump cell controller. During a normal operation time of the sensor element, the pump cell controller executes a normal time measurement pump control process of pumping out the oxygen in a measurement chamber by controlling a measurement pump cell so that voltage for measurement reaches a normal time target value. At the start-up time of the sensor element, the pump cell controller executes a start-up time measurement pump control process of pumping out the oxygen in the measurement chamber by controlling the measurement pump cell so that the voltage for measurement reaches a start-up time target value higher than the normal time target value. When determining that the oxygen concentration in the measurement chamber is stabilized, the pump cell controller makes switching from the start-up time measurement pump control process to the normal time measurement pump control process.
    Type: Application
    Filed: May 26, 2022
    Publication date: September 22, 2022
    Inventors: Taku OKAMOTO, Soichiro YOSHIDA, Ryo HASHIKAWA
  • Publication number: 20220283114
    Abstract: A gas sensor includes a sensor element and a pump cell controller. The pump cell controller performs a normal time control process after a heater control process is started, the normal time control process including a main pump control process, an auxiliary pump control process of controlling an auxiliary pump cell so that a voltage for auxiliary pump reaches a target value, and a normal time measurement pump control process of pumping out oxygen in a measurement chamber by controlling the measurement pump cell so that a measurement voltage reaches a normal time target value. In an early stage of the normal time control process, the pump cell controller performs a correction process of correcting the target value of the voltage for auxiliary pump to a value higher than a target value in a period after the early stage.
    Type: Application
    Filed: May 26, 2022
    Publication date: September 8, 2022
    Inventors: Taku OKAMOTO, Soichiro YOSHIDA, Ryo HASHIKAWA
  • Patent number: 11391690
    Abstract: A sensor element used to detect, using a limiting current method, the specific gas concentration in a rich-atmosphere measurement-object gas. The sensor element includes a layered body in which a measurement-object gas distribution portion is provided, an adjustment pump cell that has an adjustment pump electrode arranged in an oxygen concentration adjustment space in the measurement-object gas distribution portion. The adjustment pump electrode contains Pt and Au, and a Au/Pt ratio (=the area of a portion where Au is exposed/the area of a portion where Pt is exposed) measured using X-ray photoelectron spectroscopy (XPS) is greater than or equal to 0.3 but not greater than 0.63.
    Type: Grant
    Filed: December 3, 2019
    Date of Patent: July 19, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventors: Taku Okamoto, Nobukazu Ikoma, Osamu Nakasone
  • Patent number: 11378542
    Abstract: A gas sensor detects the concentration of a specific gas on the basis of a pump current that flows when oxygen is pumped out from a measurement chamber, so that an oxygen concentration in the measurement chamber becomes a predetermined low concentration, the oxygen that is pumped out being oxygen that is generated when the specific gas is reduced in measurement chamber in a case where the specific gas is an oxide or being oxygen that is generated when a gas obtained as a result of conversion of the specific gas to an oxide is reduced in the measurement chamber in a case where the specific gas is a non-oxide. Further, the gas sensor corrects the pump current or the concentration of the specific gas on the basis of the oxygen concentration of the measurement-object gas when the measurement-object gas is in a rich atmosphere.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: July 5, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventors: Osamu Nakasone, Taku Okamoto, Nobukazu Ikoma
  • Patent number: 11378543
    Abstract: A gas sensor includes an element body, an inner main pump electrode, an inner auxiliary pump electrode, an inner preliminary pump electrode, a measurement electrode, a reference electrode, a measurement voltage detection device, a specific gas concentration detection device. The inner preliminary pump electrode, the inner main pump electrode, the inner auxiliary pump electrode and the measurement electrode include each contain a noble metal having catalytic activity. At least one of the inner preliminary pump electrode and the inner main pump electrode contains no noble metal having a catalytic activity suppression ability, the catalytic activity suppression ability being an ability to suppress the catalytic activity of the noble metal having the catalytic activity from being exhibited to the specific gas. The inner auxiliary pump electrode contains a noble metal having the catalytic activity suppression ability.
    Type: Grant
    Filed: June 26, 2019
    Date of Patent: July 5, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventors: Kunihiko Nakagaki, Taku Okamoto, Osamu Nakasone, Nobukazu Ikoma
  • Publication number: 20220178869
    Abstract: A gas sensor includes a sensor element including an element body, a measurement pump cell being configured to pump out oxygen from surroundings of an inner measurement electrode to surroundings of an outer measurement electrode, and a measurement voltage detection sensor cell that detects a measurement voltage between a reference electrode and the inner measurement electrode, and a pump cell controller that executes a normal time measurement pump control process of pumping out oxygen in the measurement chamber during a normal operation time of the sensor element so that the measurement voltage reaches a normal time target value, and executes a start-up time measurement pump control process of pumping out oxygen in the measurement chamber at a start-up time of the sensor element earlier than the normal operation time so that the measurement voltage reaches a start-up time target value higher than the normal time target value.
    Type: Application
    Filed: November 22, 2021
    Publication date: June 9, 2022
    Inventors: Taku OKAMOTO, Soichiro YOSHIDA, Ryo HASHIKAWA
  • Patent number: 11333055
    Abstract: A catalyst deterioration diagnosis method is a method for a system. The system includes a stepped transmission or a continuously variable transmission connected to an internal combustion engine, a catalyst into which an exhaust gas from the internal combustion engine is introduced, and a gas sensor having sensitivity to ammonia that outputs a detection value corresponding to a component of an exhaust gas that has passed through the catalyst. The catalyst deterioration diagnosis method includes the following steps. Monitoring of temporary increase of a detection value of the gas sensor is started, and thereby a temporarily increased amount of the detection value of the gas sensor is acquired. The monitoring is started when upshifting of the stepped transmission or pseudo-upshifting of the continuously variable transmission is performed. Whether or not the temporarily increased amount is larger than a threshold amount is determined.
    Type: Grant
    Filed: August 29, 2019
    Date of Patent: May 17, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventors: Taku Okamoto, Osamu Nakasone
  • Publication number: 20220113280
    Abstract: A gas sensor includes an element body, an adjustment pump cell, a preliminary pump cell, a measurement electrode, a reference electrode, a specific gas concentration detection device. The element body provides a measurement-object gas flow section to allow a measurement-object gas to be introduced into and flow through the measurement-object gas flow section. The adjustment pump cell adjusts an oxygen concentration of an oxygen concentration adjustment chamber in the measurement-object gas flow section. The preliminary pump cell pumps oxygen into a preliminary chamber to prevent the measurement-object gas in a low-oxygen atmosphere from reaching the oxygen concentration adjustment chamber, the preliminary chamber being provided upstream of the oxygen concentration adjustment chamber in the measurement-object gas flow section.
    Type: Application
    Filed: December 22, 2021
    Publication date: April 14, 2022
    Inventors: Kunihiko NAKAGAKI, Taku OKAMOTO, Osamu NAKASONE, Nobukazu IKOMA
  • Publication number: 20220107287
    Abstract: Provided is a sensor element and a gas sensor capable of suppressing a disadvantage resulting from the structure of a diffusion control unit while suppressing the influence of a dynamic pressure resulting from an operation of an engine. A sensor element is used to measure the concentration of a predetermined gas component in a measurement target gas. The sensor element includes an oxygen ion-conductive solid electrolyte. A gas introduction opening is formed at one end portion in the long side direction of the sensor element. An internal cavity is formed inside the sensor element. A diffusion control unit is formed between the gas introduction opening and the internal cavity. The diffusion control unit includes first and second diffusion control units that are arranged along the long side direction. The first diffusion control unit includes a first opening portion. The second diffusion control unit includes a second opening portion.
    Type: Application
    Filed: September 28, 2021
    Publication date: April 7, 2022
    Inventors: Taku OKAMOTO, Yuichiro KONDO
  • Patent number: 11293894
    Abstract: A gas sensor includes a structural body made up from a solid electrolyte that exhibits oxygen ion conductivity, a gas introduction port formed in the structural body, a preliminary chamber communicating with the gas introduction port and equipped with a preliminary pump electrode, a main chamber communicating with the preliminary chamber and equipped with a main pump electrode, and a measurement chamber communicating with the main chamber and equipped with a measurement electrode. In the gas sensor, at least a surface of the preliminary pump electrode is made of a material which exhibits a low activity with respect to a reaction between ammonia and oxygen.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: April 5, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventors: Kunihiko Nakagaki, Taku Okamoto, Nobukazu Ikoma
  • Patent number: 11293893
    Abstract: In a gas sensor configured to measure the concentrations of a plurality of components in the presence of oxygen, in the interior of a structural body made from an oxygen ion conductive solid electrolyte, a preliminary chamber having a mixed potential electrode, an oxygen concentration adjustment chamber having a main pump electrode, and a measurement chamber having a measurement electrode are formed in a manner communicating in this order. While oxygen within the gas to be measured is being discharged by the main pump electrode and the measurement electrode, the NH3 concentration within the gas to be measured is measured by a mixed potential V0 of the mixed potential electrode.
    Type: Grant
    Filed: June 12, 2019
    Date of Patent: April 5, 2022
    Assignee: NGK INSULATORS, LTD.
    Inventor: Taku Okamoto
  • Patent number: 11174807
    Abstract: In a method of performing active control between a lean operation state and a rich operation state on a vehicle engine including a three way catalyst in an exhaust path, on a downstream side with respect to the three way catalyst in the exhaust path, a limited current type NOx sensor having NH3 interference and also capable of detecting a change in an oxygen concentration on the downstream side is disposed, and an operation state of the vehicle engine is switched between a lean operation state and a rich operation state at a timing when a detection of a change in an oxygen concentration in an exhaust air flowing out from the three way catalyst or a detection of NOx or NH3 is performed first by the NOx sensor.
    Type: Grant
    Filed: August 6, 2020
    Date of Patent: November 16, 2021
    Assignee: NGK INSULATORS, LTD.
    Inventors: Taku Okamoto, Osamu Nakasone
  • Publication number: 20210270768
    Abstract: A gas sensor includes a sensor element including an element body, a first electrode, a second electrode, and a heater; a voltage acquisition section that acquires a voltage between the first electrode and the second electrode; a heater power supply; an external common lead that serves as both at least part of an electric circuit used to acquire the voltage by providing electrical continuity between the first electrode and the voltage acquisition section and at least part of an electric circuit used to supply an electric power from the heater power supply to the heater and that is disposed outside the sensor element; and a correction section that derives a value of a voltage drop in the external common lead in accordance with a heater current and that corrects the voltage acquired by the voltage acquisition section in accordance with the derived value of the voltage drop.
    Type: Application
    Filed: February 9, 2021
    Publication date: September 2, 2021
    Inventors: Taku OKAMOTO, Yuichiro KONDO, Osamu NAKASONE