| US 7,564,173 B2 | ||
| Piezoelectric actuator device for ultrasonic motor | ||
| Masahiko Namerikawa, Seto (Japan); Masayuki Uetani, Kasugai (Japan); Hideki Shimizu, Ohbu (Japan); Tomohiro Yamada, Komaki (Japan); and Nobuo Takahashi, Kasugai (Japan) | ||
| Assigned to NGK Insulators, Ltd., Nagoya-shi (Japan) | ||
| Filed on Aug. 21, 2007, as Appl. No. 11/842,233. | ||
| Claims priority of provisional application 60/839475, filed on Aug. 23, 2006. | ||
| Claims priority of provisional application 60/864434, filed on Nov. 06, 2006. | ||
| Claims priority of provisional application 60/867418, filed on Nov. 28, 2006. | ||
| Prior Publication US 2008/0048526 A1, Feb. 28, 2008 | ||
| Int. Cl. H01L 41/083 (2006.01) | ||
| U.S. Cl. 310—328 [310/366] | 7 Claims |
| 1. An ultrasonic motor piezoelectric actuator element using a primary longitudinal mode and a secondary bending mode, said
ultrasonic motor piezoelectri c actuator element comprising:
a stacked piezoelectric element in which piezoelectric layers and electrode layers are stacked alternately in such a manner
that the electrode layers divide the piezoelectric layers into two approximately equal portions;
wherein a piezoelectric inactive region is formed from a surface portion to a center portion in a thickness direction of the
stacked piezoelectric element.
|