| 摘要 |
PROBLEM TO BE SOLVED: To provide a case-encapsulated piezoelectric actuator wherein dimension change due to temperature change is eliminated when the case-encapsulated piezoelectric actuator is used in a wide temperature range, and displacement which is caused by applying a voltage can be transmitted without loss. SOLUTION: In a laminated piezoelectric ceramics, a laminate is formed wherein lamination is so performed that at least three piezoelectric ceramic layers and at least two internal electrode layers are arranged. Insulator layers are so formed on a side surface of the laminate that the internal electrodes are made opposite electrode every other layer. For another way, a part of the internal electrodes is not formed, and a part of the piezoelectric ceramics is made insulator layers. External electrodes are formed on the insulator layers. The laminated piezoelectric ceramics is encapsulated in an enclosed case, and a piezoelectric actuator is formed. In the piezoelectric actuator, the sum of <coefficient of linear expansion×length in a laminating direction> of the laminated piezoelectric ceramics and displacement due to thermal expansion which is <coefficient of linear expansion×length> of members arranged at both ends in a displacement direction of the laminated piezoelectric ceramics is nearly zero. COPYRIGHT: (C)2003,JPO
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