Patent ID: 9407173
Filing Date: 2016-08-02
CPC Classification: B06B,H01L,H02N

Claim Text:
1. A piezoelectric actuator for an ultrasonic motor, comprising: a plate-shaped body formed of a piezoelectric material; a first electrode having a pinwheel wing shape formed on one of upper and lower surfaces of the plate-shaped body and operable in a torsional vibration mode by varying lengths of the electrode wings from a central point of the piezoelectric actuator; a plurality of second electrodes formed between the pinwheel wings to be separated from the first electrode; a third electrode formed on a surface opposite the surface on which the first electrode and the plurality of second electrodes are formed; and a side groove formed in a circular shape along a side surface of the plate-shaped body, wherein one of the first electrode and the plurality of second electrode is connected to an input voltage, wherein an electrode of the first electrode and the plurality of seconds electrodes to which the input voltage is not connected, and wherein the third electrode is connected to a common ground.