Patents by Inventor Hirotaka Oikawa

Hirotaka Oikawa 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: 11920951
    Abstract: Provided is a photoelectric sensor capable of being securely joined to a housing while being sufficiently resistant to dirt. A housing 12 of a photoelectric sensor 10 has an opening 121 which allows passage of at least one of light from a light projecting unit 14 and light to a light receiving unit 16, and is provided with a cover lens 50 which covers the opening 121 and is optically transmissive. The cover lens 50 is joined to an edge portion 121a of the housing 12 defining the opening 121. An outer surface 51 of the cover lens 50 is provided with antifouling coating 61. An inner surface 52 of the cover lens 50 has a joint portion 52a which is in contact with the edge portion 121a and is not provided with the antifouling coating 61.
    Type: Grant
    Filed: February 28, 2020
    Date of Patent: March 5, 2024
    Assignee: OMRON Corporation
    Inventors: Jumpei Nakamura, Hirotaka Nakashima, Kazunari Komai, Takahiro Oikawa
  • Patent number: 10001183
    Abstract: A brake apparatus comprising: a caliper having a piston configured to move a brake pad to be pressed on a disc rotor rotating with a wheel; a thrust retaining mechanism located in the caliper to thrust the piston and maintain braking force exerted by the thrust piston; an electric motor mounted on the caliper to operate the thrust retaining mechanism; and a controller configured to apply electric current to the electric motor in response to an application command or a release command, thereby perform control according to the commands, wherein the controller, upon receiving a release command, configured to operate the electric motor to reduce braking force exerted by the piston by performing current maintenance control which continuously applies electric current to the electric motor and switching control which successively switches between a larger and a smaller amount of electric current applied to the electric motor.
    Type: Grant
    Filed: July 30, 2015
    Date of Patent: June 19, 2018
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Kimio Nishino, Kenichiro Matsubara, Wataru Yokoyama, Tatsuro Kobune, Hirotaka Oikawa
  • Patent number: 9731693
    Abstract: A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor.
    Type: Grant
    Filed: September 23, 2013
    Date of Patent: August 15, 2017
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu Sakashita, Hirotaka Oikawa
  • Patent number: 9475472
    Abstract: A brake system includes a brake apparatus. This brake apparatus is configured to keep a vehicle braked by an electric mechanism in response to a parking brake request signal, and brake the vehicle by supply of a hydraulic pressure from a hydraulic source in response to an operation performed on a brake pedal. The brake system further includes a controller configured to drive the electric mechanism until a target pressing force is acquired to establish a brake holding state in response to the parking brake request signal. The controller is configured to change the target pressing force according to a change in a hydraulic pressure in the brake apparatus after starting driving the electric mechanism in response to the parking brake request signal.
    Type: Grant
    Filed: August 26, 2014
    Date of Patent: October 25, 2016
    Assignee: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu Sakashita, Hirotaka Oikawa, Kimio Nishino
  • Publication number: 20160032995
    Abstract: A brake apparatus comprising: a caliper having a piston configured to move a brake pad to be pressed on a disc rotor rotating with a wheel; a thrust retaining mechanism located in the caliper to thrust the piston and maintain braking force exerted by the thrust piston; an electric motor mounted on the caliper to operate the thrust retaining mechanism; and a controller configured to apply electric current to the electric motor in response to an application command or a release command, thereby perform control according to the commands, wherein the controller, upon receiving a release command, configured to operate the electric motor to reduce braking force exerted by the piston by performing current maintenance control which continuously applies electric current to the electric motor and switching control which successively switches between a larger and a smaller amount of electric current applied to the electric motor.
    Type: Application
    Filed: July 30, 2015
    Publication date: February 4, 2016
    Inventors: Kimio NISHINO, Kenichiro MATSUBARA, Wataru YOKOYAMA, Tatsuro KOBUNE, Hirotaka OIKAWA
  • Patent number: 8985284
    Abstract: There is provided a disk brake that can hold a required thrust force and maintain a stop state of a vehicle without increasing complexity in the disk brake even if the disk brake is operated in a high temperature state of a brake pad and then a temperature of the brake pad is reduced. In the disk brake 1, an electric motor 8 is driven to thrust a piston 6, the piston 6 presses the brake pad 5 against a disk rotor 2, and the piston 6 is held in the pressed position, the electric motor 8 is re-driven after a predetermined time from a start of holding of the piston 6, and a driving condition of the electric motor 8 after re-driving is determined based on a change in value of a current supplied to the electric motor 8 by the re-driving.
    Type: Grant
    Filed: October 5, 2011
    Date of Patent: March 24, 2015
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Takahiro Ito, Kenichiro Matsubara, Hirotaka Oikawa
  • Publication number: 20150061365
    Abstract: A brake system includes a brake apparatus. This brake apparatus is configured to keep a vehicle braked by an electric mechanism in response to a parking brake request signal, and brake the vehicle by supply of a hydraulic pressure from a hydraulic source in response to an operation performed on a brake pedal. The brake system further includes a controller configured to drive the electric mechanism until a target pressing force is acquired to establish a brake holding state in response to the parking brake request signal. The controller is configured to change the target pressing force according to a change in a hydraulic pressure in the brake apparatus after starting driving the electric mechanism in response to the parking brake request signal.
    Type: Application
    Filed: August 26, 2014
    Publication date: March 5, 2015
    Inventors: Takayasu SAKASHITA, Hirotaka OIKAWA, Kimio NISHINO
  • Patent number: 8972140
    Abstract: A disc brake apparatus, in which, at the time of a parking brake release operation, a control unit configured to control driving of an electric motor drives the electric motor so as to cause a piston holding mechanism to stop holding a piston, detects separation of a brake pad from a disk, and then stops driving the electric motor after driving the electric motor by a predetermined amount based on a current value of the electric motor.
    Type: Grant
    Filed: March 15, 2013
    Date of Patent: March 3, 2015
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Tomoyuki Kotake, Hirotaka Oikawa
  • Patent number: 8833526
    Abstract: An electric brake apparatus compares an estimated thrust force corresponding to a predetermined rotational position of an electric motor, which is calculated from an electric current/thrust force conversion function, with a reference thrust force based on a rotational position/thrust force table indicating a relationship between the rotational position of the electric motor and a thrust force of a piston to correct and update the electric current/thrust force conversion function, thereby maintaining a predetermined control accuracy despite wear of a brake pad and other changes over time.
    Type: Grant
    Filed: January 30, 2012
    Date of Patent: September 16, 2014
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Daisuke Goto, Hirotaka Oikawa, Takuya Usui
  • Patent number: 8784833
    Abstract: Transplacental enzyme replacement therapy (ERT) is disclosed for deficiency of a polypeptide such as a tissue-nonspecific alkaline phosphatase (TNSALP) by administering a pharmaceutical composition that comprises a water-soluble TNSALP portion, e.g., C-terminus-truncated TNSALP peptide-bonded to an IgG1 antibody Fc portion, to a pregnant animal whose fetus or embryo is in need of such therapy. Also contemplated is a method for treating a metabolic disorder, such as HPP, in a fetus or embryo where a fusion protein that comprises a Fc fragment of an IgG1 antibody peptide-bonded to TNSALP is administered to a pregnant mother. The protein crosses the placenta of the mother and enters the fetal blood stream. The protein is taken up into fetal tissue such that the TNSALP restores normal metabolic activity in the fetus.
    Type: Grant
    Filed: January 17, 2011
    Date of Patent: July 22, 2014
    Assignee: Saint Louis University
    Inventors: William S. Sly, Jeffrey H. Grubb, Shunjl Tomatsu, Adriana Maria Monta{umlaut over (n)}o Suarez, Hirotaka Oikawa
  • Publication number: 20140095042
    Abstract: A disk brake apparatus includes a piston thrust mechanism disposed in a caliper and including a thrust member configured to thrust a piston by an electric motor, and a piston holding mechanism configured to hold the thrust piston. When the piston holding mechanism release the holding of the thrust piston, the controller acquires a hydraulic pressure supplied to the caliper. If the hydraulic pressure is a predetermined value or higher, the controller determines whether a thrust force generated by the electric motor is released based on a time period from issue of an instruction to release the holding of the piston and a start of driving of the electric motor. If the hydraulic pressure is lower than the predetermined value, the controller determines whether the thrust force generated by the electric motor is released based on a change status of a current for driving the electric motor.
    Type: Application
    Filed: September 23, 2013
    Publication date: April 3, 2014
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Takayasu SAKASHITA, Hirotaka OIKAWA
  • Patent number: 8676409
    Abstract: Even when a rigidity table stored in a RAM at the time of a start of a brake operation does not coincide with an actual rigidity characteristic of an electric caliper which changes according to brake conditions including how often and how long a brake operation is applied, it is possible to reduce a deviation between a pressing force instruction value and a generated pressing force by updating the characteristic of the relation between a pressing force instruction value and rotational position each time an estimated thrust force value is calculated during one brake operation. It is possible to steadily keep followability to a pressing force instruction according to an actual state of the rigidity characteristic of the electric caliper, thereby ensuring generation of an appropriate brake force.
    Type: Grant
    Filed: March 23, 2011
    Date of Patent: March 18, 2014
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Hiroki Takeda, Hirotaka Oikawa, Junichi Ikeda, Daisuke Goto
  • Publication number: 20130261917
    Abstract: The present invention provides a disc brake apparatus, in which, at the time of a parking brake release operation, a control unit configured to control driving of an electric motor drives the electric motor so as to cause a piston holding mechanism to stop holding a piston, detects separation of a brake pad from a disk, and then stops driving the electric motor after driving the electric motor by a predetermined amount based on a current value of the electric motor.
    Type: Application
    Filed: March 15, 2013
    Publication date: October 3, 2013
    Applicant: HITACHI AUTOMOTIVE SYSTEMS, LTD.
    Inventors: Tomoyuki KOTAKE, Hirotaka OIKAWA
  • Patent number: 8408660
    Abstract: A disc brake apparatus including a disc brake having a parking brake mechanism operated by an electric motor as a drive source to mechanically hold a piston in a braking position even after the hydraulic pressure is released; and a controller for supplying a predetermined amount of hydraulic pressure from a hydraulic control unit to caliper caliper, based on a parking-brake indicating signal from a parking brake switch and for operating the parking brake mechanism. In a case in which a brake pedal is being operated when a parking-brake indicating signal is input, the parking brake mechanism is operated in a state in which a hydraulic pressure in the caliper is at a predetermined pressure, after the operation of the brake pedal is finished, so as to reduce a hydraulic pressure required for a release of a brake pedal.
    Type: Grant
    Filed: August 28, 2007
    Date of Patent: April 2, 2013
    Assignee: Hitachi, Ltd.
    Inventors: Hirotaka Oikawa, Takuya Obata
  • Patent number: 8272699
    Abstract: A brake apparatus is provided that can make a ratio between a front wheel braking force and a rear wheel braking force that is actually generated into an arbitrary ratio.
    Type: Grant
    Filed: August 14, 2009
    Date of Patent: September 25, 2012
    Assignee: Hitachi Automotive Systems, Ltd.
    Inventors: Shinya Imura, Kenichiro Matsubara, Hirotaka Oikawa
  • Patent number: 8239100
    Abstract: An electric braking apparatus which first moves a piston in a detaching direction or passes a current to move the piston in the detaching direction in order to detect a pad contacting position. Furthermore, while the piston moves in the detaching direction, pad non-contact judgment is performed. After a pad non-contact state is confirmed, the piston is moved in a pressing direction to detect the pad contacting position. When the piston does not move in the detaching direction, it is judged that a parking brake has an ON-state, and it is waited until a host system instructs parking brake release.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: August 7, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Kentarou Ueno, Mitsuhide Sasaki, Hirotaka Oikawa, Tohma Yamaguchi, Hiroki Takeda
  • Publication number: 20120193177
    Abstract: The present invention provides an electric brake apparatus capable of maintaining predetermined control accuracy despite wear of a brake pad and other changes over time. The electric brake apparatus compares an estimated thrust force corresponding to a predetermined rotational position of an electric motor, which is calculated from an electric current/thrust force conversion function, with a reference thrust force based on a rotational position/thrust force table indicating a relationship between the rotational position of the electric motor and a thrust force of a piston to correct and update the electric current/thrust force conversion function, thereby maintaining predetermined control accuracy despite wear of the brake pad and other changes over time.
    Type: Application
    Filed: January 30, 2012
    Publication date: August 2, 2012
    Inventors: Daisuke Goto, Hirotaka Oikawa, Takuya Usui
  • Publication number: 20120085599
    Abstract: There is provided a disk brake that can hold a required thrust force and maintain a stop state of a vehicle without increasing complexity in the disk brake even if the disk brake is operated in a high temperature state of a brake pad and then a temperature of the brake pad is reduced. In the disk brake 1, an electric motor 8 is driven to thrust a piston 6, the piston 6 presses the brake pad 5 against a disk rotor 2, and the piston 6 is held in the pressed position, the electric motor 8 is re-driven after a predetermined time from a start of holding of the piston 6, and a driving condition of the electric motor 8 after re-driving is determined based on a change in value of a current supplied to the electric motor 8 by the re-driving.
    Type: Application
    Filed: October 5, 2011
    Publication date: April 12, 2012
    Applicant: Hitachi Automotive Systems, Ltd.
    Inventors: Takahiro ITO, Kenichiro Matsubara, Hirotaka Oikawa
  • Patent number: 8096122
    Abstract: An electric booster according to the present invention comprises a booster piston disposed around an input piston so as to movable relative to the input piston. The booster piston and input piston also serve as a primacy piston of a tandem master cylinder. A brake fluid pressure is generated in the tandem master cylinder by an input thrust force provided from a brake pedal to the input piston and a booster thrust force provided from the electronic actuator to the booster piston. In this electric booster, a slide hole is formed through the secondary piston of the tamed master cylinder in the axial direction therefore, and a rod member is slidably disposed through the slide hole. When the fluid pressure is not increased in the primary pressure chamber, due to the fluid pressure in the secondary pressure chamber, the rod member comes to abut against the input piston, and a reactive force in the secondary pressure chamber is returned to the brake pedal.
    Type: Grant
    Filed: December 22, 2008
    Date of Patent: January 17, 2012
    Assignee: Hitachi, Ltd.
    Inventors: Junichi Ikeda, Hirotaka Oikawa, Takayuki Ohno
  • Publication number: 20110300143
    Abstract: The invention contemplates transplacental enzyme replacement therapy (ERT) for deficiency of a polypeptide such as a tissue-nonspecific alkaline phosphatase (TNSALP) by administering a before-described pharmaceutical composition to a pregnant animal whose fetus or embryo is in need of such therapy. The fusion protein of such a composition comprises a water-soluble TNSALP portion, e.g., C-terminus-truncated TNSALP peptide-bonded to an IgG1 antibody Fc portion. The invention also contemplates a method for treating a metabolic disorder, such as HPP, in a fetus or embryo were a protein is administered to a pregnant mother. The fusion protein comprises a Fc fragment of an IgG1 antibody peptide-bonded to TNSALP. The protein crosses the placenta of the mother and enters the fetal blood stream. The protein is taken up into fetal tissue such that the TNSALP restores normal metabolic activity in the fetus.
    Type: Application
    Filed: January 17, 2011
    Publication date: December 8, 2011
    Applicant: SAINT LOUIS UNIVERSITY
    Inventors: William S. Sly, Jeffrey H. Grubb, Shunji Tomatsu, Adriana Maria MontaƱo Suarez, Hirotaka Oikawa