Patents by Inventor Takamitsu Kubota

Takamitsu Kubota 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: 7583078
    Abstract: A method of correcting temperature characteristic of a rotation angle detecting device that includes a permanent magnet, a magnetic core, a Hall element that rotates relative to the permanent magnet when a rotating object rotates to provide an output signal. The method includes a step of setting temperature correction values for correcting a temperature characteristic of the rotation angle detecting device according to magnetic flux density. The magnetic flux density is divided into a plurality of grade ranges and the temperature correction values are respectively set for the grade ranges.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: September 1, 2009
    Assignee: DENSO Corporation
    Inventors: Takamitsu Kubota, Yoshiyuki Kono, Tomohiro Ito
  • Publication number: 20090091312
    Abstract: A displacement measuring device includes a stationary magnetic member for providing an accommodation space and a first and second magnetic circuits, a movable magnetic member disposed in the accommodation space to move in its longitudinal direction, a magnetic sensor for sensing magnetic flux flowing in the first and second magnetic circuits. The stationary member includes a sensor supporting member disposed in line with an axis of symmetry, a pair of yoke members axisymmetrically disposed at opposite sides of the sensor supporting member, a pair of permanent magnets each of which is disposed between one of the yoke members and the sensor supporting member. The permanent magnets are polarized so that magnetic flux flows in one of the magnetic circuits opposite in direction to magnetic flux flowing in the other magnetic circuit. The magnetic sensor is disposed on the sensor supporting member to confront the moving magnetic member at a first air gap.
    Type: Application
    Filed: September 25, 2008
    Publication date: April 9, 2009
    Applicant: DENSO CORPORATION
    Inventors: Tomohiro Ito, Takamitsu Kubota, Yoshiyuki Kono
  • Publication number: 20090066322
    Abstract: A linear displacement detection apparatus is configured to convert a linear displacement of a shaft into a rotary displacement of a sensor rotor of a rotary displacement sensor so as to detect the linear displacement. A sensor lever is fixed to the sensor rotor and rotatable about an axis of the sensor rotor. A sensor rod is located closer to the shaft than the sensor lever and configured to transmit the linear displacement of the shaft to the sensor lever. A bearing member is located closer to the shaft than the sensor rod and configured to release rocking of the shaft.
    Type: Application
    Filed: September 10, 2008
    Publication date: March 12, 2009
    Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroyuki SHINTANI, Hisataka Okado, Yoshiyuki Kono, Takashi Kawashima, Takamitsu Kubota, Shinji Ikeda
  • Publication number: 20070126419
    Abstract: A method of correcting temperature characteristic of a rotation angle detecting device that includes a permanent magnet, a magnetic core, a Hall element that rotates relative to the permanent magnet when a rotating object rotates to provide an output signal. The method includes a step of setting temperature correction values for correcting a temperature characteristic of the rotation angle detecting device according to magnetic flux density. The magnetic flux density is divided into a plurality of grade ranges and the temperature correction values are respectively set for the grade ranges.
    Type: Application
    Filed: November 29, 2006
    Publication date: June 7, 2007
    Applicant: DENSO CORPORATION
    Inventors: Takamitsu Kubota, Yoshiyuki Kono, Tomohiro Ito
  • Patent number: 7161349
    Abstract: In a magnetic rotation angle sensor for detecting a rotation angle of a detection target, a yoke covers outer circumferences of a magnet and a Hall device. One of the magnet and the magnetic flux density detection device rotates together with the detection target. The Hall IC is radially shifted from a rotation center of the detection target. The magnetic flux density detection device has a detection surface that is in parallel to one of a tangential direction and a normal direction of a turning circle. The magnet is magnetized in the one of the tangential direction and the normal direction of the turning circle.
    Type: Grant
    Filed: May 12, 2006
    Date of Patent: January 9, 2007
    Assignee: Denso Corporation
    Inventors: Tomohiro Itoh, Takamitsu Kubota, Yoshiyuki Kono
  • Publication number: 20060261804
    Abstract: In a magnetic rotation angle sensor for detecting a rotation angle of a detection target, a yoke covers outer circumferences of a magnet and a Hall device. One of the magnet and the magnetic flux density detection device rotates together with the detection target. The Hall IC is radially shifted from a rotation center of the detection target. The magnetic flux density detection device has a detection surface that is in parallel to one of a tangential direction and a normal direction of a turning circle. The magnet is magnetized in the one of the tangential direction and the normal direction of the turning circle.
    Type: Application
    Filed: May 12, 2006
    Publication date: November 23, 2006
    Applicant: DENSO CORPORATION
    Inventors: Tomohiro Itoh, Takamitsu Kubota, Yoshiyuki Kono
  • Patent number: 6845649
    Abstract: A method for calibrating a rotation angle sensor having a magnet, a magnetic detector disposed in a magnetic field of the magnet for outputting a detected value indicative of a direction of the magnetic field that varies in accordance with a rotation angle of a rotatable member, and an output circuit which transforms the detected value to an output value in accordance with a transforming characteristic and outputs the output value, the method entailing: assembling the magnet, the magnetic detector and the output circuit to a device that has the rotatable member; rotating the rotatable member to a predetermined reference angle; measuring the detected value or the output value as a measured value when the rotatable member is at the reference angle; and setting the transforming characteristic based on the measured value so that the output circuit outputs a reference output value at the reference angle.
    Type: Grant
    Filed: June 7, 2002
    Date of Patent: January 25, 2005
    Assignee: Denso Corporation
    Inventors: Takamitsu Kubota, Naoyuki Kamiya, Hirofumi Hagio, Takashi Hamaoka
  • Patent number: 6819102
    Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: November 16, 2004
    Assignee: Denso Corporation
    Inventors: Hirofumi Hagio, Takashi Hamaoka, Yoshiyuki Kono, Takamitsu Kubota, Tomokazu Kondo
  • Publication number: 20040135574
    Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.
    Type: Application
    Filed: December 18, 2003
    Publication date: July 15, 2004
    Applicant: DENSO CORPORATION
    Inventors: Hirofumi Hagio, Takashi Hamaoka, Yoshiyuki Kono, Takamitsu Kubota, Tomokazu Kondo
  • Patent number: 6756780
    Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: June 29, 2004
    Assignee: Denso Corporation
    Inventors: Hirofumi Hagio, Takashi Hamaoka, Yoshiyuki Kono, Takamitsu Kubota, Tomokazu Kondo
  • Patent number: 6502544
    Abstract: If outputs of a couple of Hall ICs constituting a throttle valve position sensor are within an operating range of throttle valve position, and if a relationship between the outputs are within a predetermined error range, both the Hall ICs are determined to be normal. In contrast, if the outputs are equal to an upper clamp voltage or a lower clamp voltage, and if a relationship between the outputs is out of the predetermined error range, at least one of the Hall ICs is determined to be abnormal. Furthermore, if the outputs are within a failure reference voltage range, it is determined that there is an abnormality between the throttle valve position sensor and an ECU. In this way, abnormalities in the sensor and abnormalities between the sensor and the ECU can also be detected.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: January 7, 2003
    Assignee: Denso Corporation
    Inventors: Takamitsu Kubota, Naoyuki Kamiya, Hirofumi Hagio, Takashi Hamaoka
  • Patent number: 6499461
    Abstract: Hall ICs constituting a redundant throttle valve position sensor are used to measure a rotational angle value indicative of a position of a throttle valve and a temperature value indicative of an ambient temperature change, which is continuously monitored, around the Hall ICs. The rotational angle value measured by the Hall ICs is appropriately adjusted based on the measure temperature value of its own, and a throttle valve position is determined in an externally connected ECU based on the adjusted angle value. In addition, the temperature value measured by one Hall IC is inputted to the ECU. In the ECU, various control values, such as a resistance value of an electric motor, can be appropriately adjusted based on the measured temperature value.
    Type: Grant
    Filed: December 18, 2000
    Date of Patent: December 31, 2002
    Assignee: Denso Corporation
    Inventors: Takamitsu Kubota, Naoyuki Kamiya, Hirofumi Hagio, Takashi Hamaoka
  • Patent number: 6498479
    Abstract: The rotational angle of a rotatable object (such as the throttle valve of an automobile engine) is accurately detected by a rotational angle detector having a magnetic sensor placed in a magnetic field, the direction of which varies according to the rotational angle. The magnetic sensor generates an output that varies sinusoidally according to rotational angle. The sinusoidal output is converted into a signal that is proportional to the rotational angle under arc-sine or arc-cosine transformation. The converted signal correctly represents the rotational angle in a wide angle range. The sensor element and the circuit for converting the sensor output into the proportional output signal may be built in a single-chip integrated circuit to simplify detector structure.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: December 24, 2002
    Assignee: Denso Corporation
    Inventors: Takashi Hamaoka, Takamitsu Kubota
  • Patent number: 6483296
    Abstract: An angular position detection apparatus, which can improve a detection accuracy of the angular position by improving a linearity of an output characteristic with respect to an angular position detection apparatus, and to downsize an outer size thereof. A permanent magnet is fixed to a side surface of a rotor core, which integrally rotates with a detection target object. An inner surface of a cylindrical portion of the rotor core is closely confronted with an outer surface of a stator core. Thus, the angular position detection apparatus is formed as a radial gap type in which magnetic flux is gone through an air gap G1 between the cylindrical portion and the stator core along a radial direction. A magnetic flux detection gap portion is formed at a center portion of the stator core so as to go through toward a diametral direction. A Hall IC is arranged in the magnetic flux detection gap portion. The permanent magnet is magnetized so that lines of magnetic force therein are parallel with each other.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: November 19, 2002
    Assignee: Denso Corporation
    Inventors: Takashi Hamaoka, Takamitsu Kubota, Kunio Nanba, Akira Shimazu, Kunio Tanaka
  • Publication number: 20020166362
    Abstract: A method for calibrating a rotation angle sensor having a magnet, a magnetic detector disposed in a magnetic field of the magnet for outputting a detected value indicative of a direction of the magnetic field that varies in accordance with a rotation angle of a rotatable member, and an output circuit which transforms the detected value to an output value in accordance with a transforming characteristic and outputs the output value, the method entailing: assembling the magnet, the magnetic detector and the output circuit to a device that has the rotatable member; rotating the rotatable member to a predetermined reference angle; measuring the detected value or the output value as a measured value when the rotatable member is at the reference angle; and setting the transforming characteristic based on the measured value so that the output circuit outputs a reference output value at the reference angle.
    Type: Application
    Filed: June 7, 2002
    Publication date: November 14, 2002
    Applicant: Denso Corporation
    Inventors: Takamitsu Kubota, Naoyuki Kamiya, Hirofumi Hagio, Takashi Hamaoka
  • Patent number: 6476600
    Abstract: A compact and high-accuracy angular position measuring device is provided which has magnets installed in a rotor core and a magnetic sensor installed in a stator core. The magnetic sensor produces an output indicative of an angular position of the rotor core as a function of a change in density of magnetic flux produced by the magnets. The magnets are so arranged in the rotor core that the same poles are opposed magnetically to produce a repellent force in magnetic fields of the magnets, thereby causing the magnetic flux to go to the magnetic sensor through the rotor core. This eliminates the need for an air gap between the stator core and the poles of the magnets which is formed in a conventional device, thus allowing the device to be reduced in size and an error in output of the device to be decreased.
    Type: Grant
    Filed: January 26, 2001
    Date of Patent: November 5, 2002
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Kono, Takashi Hamaoka, Takamitsu Kubota, Takuya Fukitsuke, Tetsuya Aoki
  • Publication number: 20020130656
    Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.
    Type: Application
    Filed: May 9, 2002
    Publication date: September 19, 2002
    Applicant: DENSO CORPORATION
    Inventors: Hirofumi Hagio, Takashi Hamaoka, Yoshiyuki Kono, Takamitsu Kubota, Tomokazu Kondo
  • Patent number: 6448762
    Abstract: A rotation-angle-detection device includes a main housing, a resinous cover for covering an opening of the main housing, a permanent magnet disposed at the main housing to be rotatable in response to rotation of a throttle valve, and a magnetic sensor. The cover is longer in longitudinal direction than in lateral direction, and the magnetic sensor is fixed to the resinous cover. The magnetic sensor is disposed so that the detection direction and the longitudinal direction of the cover cross each other at a right angle.
    Type: Grant
    Filed: October 24, 2000
    Date of Patent: September 10, 2002
    Assignee: Denso Corporation
    Inventors: Yoshiyuki Kono, Takashi Hamaoka, Takamitsu Kubota, Katsuya Torii, Kunio Tanaka
  • Patent number: 6407543
    Abstract: Non-contact type Hall ICs detecting an rotation angle of a throttle valve, a stator core strengthening a magnetic field around the Hall ICs, a lead frame connecting the Hall ICs to an outside ECU are integrated in a sensor cover by resin molding. Thus, the Hall ICs, the stator core, and the lead frame are accurately positioned in the sensor cover. As a result, the Hall ICs are accurately positioned with respect to a permanent magnet disposed in a shaft side of the throttle valve, thereby improving an accuracy of detecting the rotation angle of the throttle valve.
    Type: Grant
    Filed: October 13, 2000
    Date of Patent: June 18, 2002
    Assignee: Denso Corporation
    Inventors: Hirofumi Hagio, Takashi Hamaoka, Yoshiyuki Kono, Takamitsu Kubota, Tomokazu Kondo
  • Patent number: 6356073
    Abstract: A stator core has a detecting portion located on a center of a gap penetrating the stator core in a diametric direction and a Hall IC arranged in the detecting portion. Large gap portions each having a distance G3 wider than a distance G2 of the detecting portion are formed on both sides of the detecting portion. Therefore, a magnetic flux passing through the stator core is concentrated into the detecting portion, and the magnetic flux density passing through the Hall IC is increased. As a result, an output of the Hall IC is increased. The large gap portion is formed to narrower a distance G4 on an outer side of the stator core, and the distance G4 is wider than an air gap G1 between the permanent magnet and the stator core.
    Type: Grant
    Filed: June 19, 2000
    Date of Patent: March 12, 2002
    Assignee: Denso Corporation
    Inventors: Takashi Hamaoka, Takamitsu Kubota, Yoshiyuki Kono