Ultrasonic actuator

An ultrasonic actuator, comprising:

• a piezoelectric element;
• and
• a flexible cable electrically connected to the piezoelectric element, wherein
• the piezoelectric element includes
• a plurality of generally rectangular piezoelectric layers,
• a power supply electrode provided on a principal surface of at least one of the plurality of piezoelectric layers,
• a counter electrode provided to face the power supply electrode with the piezoelectric layer interposed therebetween,
• a power supply external electrode provided on one of external surfaces of the piezoelectric element which is perpendicular to the principal surface of the piezoelectric layer, and which is parallel to short sides of the principal surface, the power supply external electrode being electrically coupled to the power supply electrode, and
• a counter external electrode provided on one of the external surfaces of the piezoelectric element which is perpendicular to the principal surface of the piezoelectric layer, and which is parallel to the short sides of the principal surface, the counter external electrode being electrically coupled to the counter electrode,
• the flexible cable includes
• a power supply conductive member electrically connected to the power supply external electrode, and
• a counter conductive member electrically connected to the counter external electrode,
• the power supply electrode includes
• a first power supply electrode provided on the principal surface of the at least one of the plurality of piezoelectric layers, and
• a second power supply electrode provided on the principal surface which has the first power supply electrode thereon or on a principal surface of another one of the piezoelectric layers which is different from the principal surface that has the first power supply electrode thereon, the second power supply electrode being not electrically coupled to the first power supply electrode,
• the power supply external electrode includes
• a first power supply external electrode provided on the one of the external surfaces of the piezoelectric element which is perpendicular to the principal surface of the piezoelectric layer, and which is parallel to the short sides of the principal surface, the first power supply external electrode being electrically coupled to the first power supply electrode, and
• a second power supply external electrode provided on the one of the external surfaces of the piezoelectric element which is perpendicular to the principal surface of the piezoelectric layer, and which is parallel to the short sides of the principal surface, the second power supply external electrode being electrically coupled to the second power supply electrode,
• the power supply conductive member includes
• a first power supply conductive member electrically connected to the first power supply external electrode,
• a second power supply conductive member electrically connected to the second power supply external electrode,
• the first power supply external electrode and the second power supply external electrode are provided on one of two external surfaces of the piezoelectric element which are perpendicular to the principal surface of the piezoelectric layer, and which are parallel to the short sides of the principal surface, and are not provided on the other one of the two external surfaces, and
• the counter external electrode is provided on the other one of the two external surfaces of the piezoelectric element which are perpendicular to the principal surface of the piezoelectric layer, and which are parallel to the short sides of the principal surface, and is not provided on the one of the two external surfaces.