To enable a piezoelectric sensor to also detect rotational accelerations without being affected by environmental conditions, such as the temperature, etc., by dividing one of the electrodes provided on both surfaces of the sensor into two parts near its center and providing mechanical-electrical conversion elements on both sides of a support.
In a piezoelectric sensor 100, a bimorph type beam formed by sticking two piezoelectric bodies to each other so that their directions of polarization may become opposite to each other is supported by means of a support 3 at the center. Cantilevers are formed on both sides of the support 3 by forming electrodes 2a and 2b separately from each other on one side face of the support 3 and an electrode 2c all over the opposite surface of the support 3. Since the beam is of a bimorph type, the flexural oscillation of the beam resulting from an acceleration can be converted into an electric signal and fetched from the electrodes. Therefore, it can be said that the element 100 is constituted by arranging mechanical-electrical conversion elements 1a and 1b on a straight line with the support 3 at the center and the elements 1a and 1b are connected to an acceleration discriminating means through a signal detecting means. The acceleration discriminating means discriminates whether an acceleration is a translational acceleration or rotational acceleration by detecting the signs of the output signals of the elements 1a and 1b.
| JP2003102183 | PIEZOELECTRIC ELEMENT CONTROL DEVICE |
| JPH11233843 | PIEZOELECTRIC BIMORPH LAMINATED ACTUATOR |
| JPH01107679 | ULTRASONIC MOTOR |
KOIKE TAKAFUMI
TOMITA YOSHIHIRO
KAWASAKI OSAMU
