Servo-type vibration detector and vibration control device

A servo-type vibration detector comprising:

• a fixed member;
• a movable member provided to be movable in a predetermined direction with respect to the fixed member, the movable member being configured to allow a magnetic flux to flow inside the movable member;
• an elastic member supporting the fixed member such that the movable member is disposed with a void portion interposed therebetween;
• a displacement detecting unit detecting displacement of the movable member in the predetermined direction;
• and
• a drive means configured to generate an electromagnetic force for returning the movable member to an origin position when the displacement detecting unit detects a relative displacement of the movable member from the origin position,
• wherein
• the displacement detecting unit includes
• a movable-side electrode member having two electrode surfaces provided on the movable member, and
• a fixed-side electrode member having two electrode surfaces provided on the fixed member,
• two sets of electrostatic capacitance sensors are configured by a combination in which each electrode surface of the movable-side electrode member and each electrode surface of the fixed-side electrode member face each other, and
• the movable-side electrode member and the fixed-side electrode member are arranged such that a gap between electrode surfaces of each of the two sets of electrostatic capacitance sensors changes in opposite phases by movement of the movable member in a predetermined direction, and a difference between output signals of the two sets of electrostatic capacitance sensors is taken to configure a differential sensor.

A servo-type vibration detector comprising:

• a fixed member;
• a movable member provided to be movable in a predetermined direction with respect to the fixed member, the movable member being configured to allow a magnetic flux to flow inside the movable member;
• an elastic member supporting the fixed member such that the movable member is disposed with a void portion interposed therebetween;
• a displacement detecting unit detecting displacement of the movable member in the predetermined direction;
• and
• a drive means configured to generate an electromagnetic force for returning the movable member to an origin position when the displacement detecting unit detects a relative displacement of the movable member from the origin position,
• wherein
• an attractive force generation unit A is configured to form an electromagnet by forming a fixed-side yoke material provided to penetrate a coil, a movable-side yoke material disposed with an open end of the fixed-side yoke material and a void, and a closed loop magnetic circuit with the fixed-side yoke material, the void portion, and the movable-side yoke material to attract the movable member including the movable-side yoke material to the coil side, and
• an attractive force generation unit B that generates a force in a direction opposite to force of the attractive force generation unit A is arranged with the movable member interposed therebetween, and a current flowing through the coil is controlled to constitute the drive means by a Maxwell stress that moves the movable member in an axial direction.