Patents by Inventor Koji Sewaki

Koji Sewaki 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: 8185308
    Abstract: Angular velocity correcting devices, angular velocity correcting methods, and navigation devices are disclosed. In some implementations, a first sensor sensitivity correcting method for considering variation of sensor sensitivity due to an oblique angle of an angular velocity detecting sensor with respect to a horizontal plane and a sensitivity error of the angular velocity detecting sensor and correcting the sensor sensitivity is enabled. A second sensor sensitivity correcting method for considering the variation of the sensor sensitivity due to the oblique angle of the angular velocity detecting sensor with respect to the horizontal plane without considering the sensitivity error and correcting the sensor sensitivity is enabled. The sensitivity error is calculated on the basis of a ratio of the sensor sensitivity obtained by the first sensor sensitivity correcting method to the sensor sensitivity obtained by the second sensor sensitivity correcting method.
    Type: Grant
    Filed: November 11, 2008
    Date of Patent: May 22, 2012
    Assignee: Alpine Electronics Inc.
    Inventors: Takayuki Watanabe, Kotaro Wakamatsu, Takehiko Sakagami, Koji Sewaki
  • Patent number: 8131418
    Abstract: Minimum and maximum values of an angular velocity signal output from a gyro while a vehicle is stationary are detected. A range of the angular velocity signal is set that is used to determine when the vehicle is stationary. When the angular velocity signal output from the gyro exceeds the range, the vehicle starts to move, offset values calculated within a set time from a movement start detection time are discarded, and an average angular velocity signal having been calculated and stored the set time before, is output as the offset value. Thus, even when the vehicle does not have a vehicle speed sensor, the stopping and starting of the movement of the vehicle can be accurately detected using the output signal from the gyro and the accurate offset value can be output.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: March 6, 2012
    Assignee: Alpine Electronics, Inc.
    Inventor: Koji Sewaki
  • Patent number: 7859434
    Abstract: The present invention provides a navigation device in which the accuracy of placement of a displayed vehicle position mark is improved at an intersection with a small angle. The navigation device weights coefficients of road candidates for consistent matching, in determining the optimal road from a plurality of matching road candidates. Accordingly, a fluctuating display of the vehicle position mark on an incorrect road at an intersection with a small angle is prevented.
    Type: Grant
    Filed: May 21, 2008
    Date of Patent: December 28, 2010
    Assignee: Alpine Electronics, Inc.
    Inventor: Koji Sewaki
  • Publication number: 20090150075
    Abstract: Angular velocity correcting devices, angular velocity correcting methods, and navigation devices are disclosed. In some implementations, a first sensor sensitivity correcting method for considering variation of sensor sensitivity due to an oblique angle of an angular velocity detecting sensor with respect to a horizontal plane and a sensitivity error of the angular velocity detecting sensor and correcting the sensor sensitivity is enabled. A second sensor sensitivity correcting method for considering the variation of the sensor sensitivity due to the oblique angle of the angular velocity detecting sensor with respect to the horizontal plane without considering the sensitivity error and correcting the sensor sensitivity is enabled. The sensitivity error is calculated on the basis of a ratio of the sensor sensitivity obtained by the first sensor sensitivity correcting method to the sensor sensitivity obtained by the second sensor sensitivity correcting method.
    Type: Application
    Filed: November 11, 2008
    Publication date: June 11, 2009
    Inventors: Takayuki Watanabe, Kotaro Wakamatsu, Takehiko Sakagami, Koji Sewaki
  • Publication number: 20080316060
    Abstract: The present invention provides a navigation device in which the accuracy of placement of a displayed vehicle position mark is improved at an intersection with a small angle. The navigation device weights coefficients of road candidates for consistent matching, in determining the optimal road from a plurality of matching road candidates. Accordingly, a fluctuating display of the vehicle position mark on an incorrect road at an intersection with a small angle is prevented.
    Type: Application
    Filed: May 21, 2008
    Publication date: December 25, 2008
    Inventor: Koji Sewaki
  • Publication number: 20080027601
    Abstract: Minimum and maximum values of an angular velocity signal output from a gyro while a vehicle is stationary are detected. A range of the angular velocity signal is set that is used to determine when the vehicle is stationary. When the angular velocity signal output from the gyro exceeds the range, the vehicle starts to move, offset values calculated within a set time from a movement start detection time are discarded, and an average angular velocity signal having been calculated and stored the set time before, is output as the offset value. Thus, even when the vehicle does not have a vehicle speed sensor, the stopping and starting of the movement of the vehicle can be accurately detected using the output signal from the gyro and the accurate offset value can be output.
    Type: Application
    Filed: June 1, 2007
    Publication date: January 31, 2008
    Inventor: Koji Sewaki