Mitsubishi Kasei Corporation

Kasei Optonix, Ltd.

Tetsuhiko Nishimura

Yukio Chida

Yasuo Oguri

Takahiro Choda

Takashi Akiba

Swapan K Basu

Shoko Inoue

Hitoshi Aihara

Junji Sato

Takashi Ichihara

Piezoelectric element and method for driving the same

The present invention relates to a piezoelectric ceramic composition for actuator which is a composition comprising a basic composition containing lead, lanthanum, alkali earth metals, zirconium, titanium and oxygen in the formulation represented by the following general formula (I): ##EQU1## where A represents one or more element(s) selected from the group consisting of Ba, Ca and Sr; 0&lt;x.ltoreq.0.07; 0.40.ltoreq.y.ltoreq.0.65; and 0&lt;m.ltoreq.0.15, wherein the ceramic composition containing, relative to the basic composition, one or more element(s) selected from the group consisting of iron, aluminum, manganese, indium and tellurium in an amount of 0.02 to 0.3% by weight in terms of Fe.sub.2 O.sub.3 or Al.sub.2 O.sub.3, 0.02 to 0.2% by weight in terms of MnO.sub.2 and 0.02 to 0.5% by weight in terms of In.sub.2 O.sub.3 or TeO.sub.2. The composition according to the present invention is higher in piezoelectric strain constant and in Curie point, so that the element can be used over a wide range of temperature. This makes the composition useful as the material for piezoelectric actuators, contributing to various industrial application fields.

Piezoelectric ceramic composition for actuator

A piezoelectric ceramic composition for actuators, composed of lead, lanthanum, zirconium, titanium, magnesium, zinc, niobium, manganese, chromium and oxygen atoms, which contains manganese in an amount of at most 1.5% by weight as calculated as Mn.sub.2 O and chromium in an amount of at most 0.5% by weight as calculated as Cr.sub.2 O.sub.3, relative to a main component composition of the formula (I):

Piezoelectric ceramic composition for actuators

The present invention relates to a piezoelectric ceramic composition for an actuator which is a ceramic composition comprising a main component represented by the formula: Pb.sub.(1-x) La.sub.x [Zr.sub.y Ti.sub.(1-y) ].sub.(1-x/4) O.sub.3 and, as a sub component, antinomy in an amount of more than 0.05% by weight and less than 3.0% by weight in terms of anitmony pentoxide relative to the main component. The piezoelectric ceramic composition of the present invention has a high electromechanical coupling factor, a high piezoelectric strain constant and a high Curie point, and is particularly excellent as a material for a piezoelectric actuator.

A piezoelectric actuator comprising a longitudinal effect-type laminated piezoelectric element composed of piezoelectric ceramic sheets laminated in their thickness direction, and a supporting member fixed to one side in the longitudinal direction of the element and being bending and capable of constraining expansion of the element.

Piezoelectric actuator

A piezoelectric ceramic composition for actuators, which consists essentially of a composite of perovskite compounds represented by the formula

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Zama, Japan

Tetsuhiko Nishimura