| 摘要 |
<p>The piezoelectric device according to the invention is provided with a rectangular crystal piece having driving electrodes on front and back main faces thereof, and a base member having two electrode pads near one short side of the crystal piece. The crystal piece is supported on the base member by first and second support portions near one short side thereof, and by an auxiliary support portion on the other short side thereof. A position of the auxiliary support portion relative to the other short side, where L is a distance between two short sides, and H is a distance from the other short side to a peripheral edge of the auxiliary support portion nearest to the other short side, is set to a position at which the distance H stays in a range of distances in which a maximum tensile stress acting on the auxiliary support portion and a maximum von Mises stress of the crystal piece are respectively within predetermined ranges of stress values. For a better resistance to impact, the position of the auxiliary support portion is set to a position at which a value of (H2+D)/L expressed in percentage is equal to or smaller than 20%, where H2 is a value included in the range of distances H in which these stresses are both maximized.</p> |
