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US 11,081,638 B2Granted
Piezoelectric element, vibrator, vibration wave motor, optical apparatus, and electronic apparatus
AssigneeCanon Kabushiki Kaisha
InventorsJumpei Hayashi, Makoto Kubota, Shinya Koyama, Tatsuo Furuta, Kanako Oshima
Life of this patent
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Abstract
A piezoelectric element includes a piezoelectric material layer and an electrode layer, wherein the piezoelectric material layer and the electrode layer are stacked on top of each other, the piezoelectric material layer includes a barium titanate-based material, and two coercive fields Ec1 and Ec2 of the piezoelectric element have the same sign and satisfy (|Ec2|−|Ec1|)≥8 kV/cm.
Claims14
A vibrator comprising:
- a piezoelectric element including a piezoelectric material and an electrode;
- a first elastic member and a second elastic member configured to sandwich the piezoelectric element;
- and
- a shaft configured to penetrate the piezoelectric element and the first and the second elastic members,
- wherein the piezoelectric material includes a barium titanate-based material,
- wherein two coercive fields Ec1 and Ec2 of the piezoelectric element have the same sign and satisfy (|Ec2|−|Ec1|)≥8 kV/cm;
- wherein a content of lead of the piezoelectric material is 1000 parts per million or less, and
- wherein pressure torque by which the first elastic member and the second elastic member are configured to be fastened each other is 2 kgf·m or more and 4 kgf·m or less.
5 more elements
Dependencies are inferred from the claim text.