Patents Assigned to Yoshiro Tomikawa
  • Patent number: 5708320
    Abstract: A vibratory gyroscope including an elongated vibrator having a central (neutral) axis (Y-axis), a drive unit for deforming the first direction such that the vibrator vibrates in a first (X) direction, an added mass attached to the vibrator at a position offset from the central axis in a second (Z) direction, and a detector formed on the vibrator. Rotation of the vibratory gyroscope about the second (Z) direction during vibration in the second direction causes Coriolis force to acting on the added mass in a direction parallel to the central axis. Because the added mass is offset from the central axis, a resulting vibration in the second (Z) direction is produced, which is detected by the detector. With this arrangement, the central axis of the vibrator is placed in parallel with the surface of rotation of the rotating system. Thus, rotations about two or three axes in each direction can be detected in such a manner that noise generation is prevented.
    Type: Grant
    Filed: October 27, 1995
    Date of Patent: January 13, 1998
    Assignees: Alps Electric Co., Ltd, Yoshiro Tomikawa
    Inventors: Kazumasa Ohnishi, Akira Satoh, Yoshiro Tomikawa
  • Patent number: 5691595
    Abstract: A vibratory gyroscope including a planar elastic vibrator having vibrator piezoelectric material layers formed on both the front and back sides. The vibrator includes a base portion and three parallel elastic pieces extending from the base portion such that the a center elastic piece is located between two side elastic pieces. Electrode layers are formed over the piezoelectric material layers which cause both the side elastic pieces and the center elastic piece to vibrate in a plane, such that the vibrations of the center elastic piece are 180.degree. out-of-phase with the side elastic pieces. When the thus-vibrated vibrator is rotated, the elastic pieces are vibrated in directions parallel to the plane due to the Coriolis force. These deformations are detected as voltage changes across the piezoelectric material layers, and the voltage changes are used to determinate the angular velocity of the vibrator.
    Type: Grant
    Filed: September 20, 1995
    Date of Patent: November 25, 1997
    Assignees: Alps Electric Co., Ltd., Yoshiro Tomikawa
    Inventors: Yoshiro Tomikawa, Kazumasa Ohnishi, Akira Satoh
  • Patent number: 5451828
    Abstract: A vibratory gyroscope, including a vibrator, which has three elastic arms separated by two slits, a driving means for generating vibration in at least one elastic arm, and a detecting means for detecting a component of vibration in a direction, which intersects with the direction of the vibration generated in an elastic arm due to Coriolis force when the vibrator rotates.
    Type: Grant
    Filed: July 22, 1994
    Date of Patent: September 19, 1995
    Assignees: Alps Electric Co., Ltd., Yoshiro Tomikawa
    Inventors: Yoshiro Tomikawa, Kazumasa Ohnishi