Patent ID: 6218770
Filing Date: 2001-04-17
Classification: H03H

Abstract:
A piezoelectric element, comprising:a piezoelectric member;means for driving said piezoelectric member; andat least one interdigital electrode including at least two comb-shaped electrodes and provided on at least one polished surface of said piezoelectric member; whereinsaid piezoelectric member is polarized and said piezoelectric element is adapted to uniformly vibrate in a stiffened mode and thereby expand and contract in a longitudinal direction thereof when said means for driving said piezoelectric member applies an electric filed between said at least two comb-shaped electrodes, and a distance between two electrode fingers of said at least two comb-shaped electrodes of said at least one interdigital electrode located at an approximate center portion of said piezoelectric member is larger than a distance between another two electrode fingers of said at least two comb-shaped electrodes of said at least one interdigital electrode located at an end portion of said piezoelectric member.