Piezoelectric actuator and information storage apparatus
AssigneeFujitsu Limited
InventorsKazuaki Kurihara, Michinori Kutami
Life of this patent
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Abstract
There are disclosed a piezoelectric actuator which can obtain large displacement at low voltage, which is small-sized and lightweight, and whose manufacture cost is low, and a small-sized lightweight information storage apparatus in which the piezoelectric actuator is incorporated, and which is provided with a small inertia moment during head driving and a high recording density. A piezoelectric actuator 200 includes a center body 200a and two spiral arms 200b, and two arms 200b are entirely in rotation symmetry and nonlinear symmetry.
Claims5
A piezoelectric actuator comprising:
- a piezoelectric layer which is formed of a piezoelectric material of a two-dimensional shape provided with a central portion, and a group of arm portions extended to the outside from the central portion in rotation symmetry and nonlinear symmetry, and which is compressed/extended in an in-layer direction;
- and
- a plurality of electrode layers for holding said piezoelectric layer.
A piezoelectric actuator comprising:
- a driving portion provided with a lamination structure including at least one piezoelectric layer of a piezoelectric material and a plurality of electrode layers for holding the piezoelectric layer, and compressed/extended in a lamination direction of the lamination structure;
- and
- a holding portion for holding a plurality of said driving portions in an arrangement of rotation symmetry and nonlinear symmetry including the lamination direction in a predetermined common plane.
An information storage apparatus comprising:
- a head portion on which a head for performing at least one of information recording and information reproduction with respect to a predetermined information storage medium is mounted;
- an arm portion for holding the head portion in such a manner that the head mounted on said head portion is disposed in the vicinity of or in contact with said information storage medium;
- an arm portion actuator for driving said arm portion to move the head mounted on the head portion held by the arm portion along said information storage medium;
- and
- a head portion actuator for rotating said head portion with respect to said arm portion and centering on a gravity center of the head portion,
- wherein said head portion actuator comprises:
- a piezoelectric layer which is formed of a piezoelectric material of a two-dimensional shape provided with a central portion, and a group of arm portions extended to the outside from the central portion in rotation symmetry and nonlinear symmetry, and which is compressed/extended in an in-layer direction;
- and
- a plurality of electrode layers for holding said piezoelectric layer.
An information storage apparatus comprising:
- a head portion on which a head for performing at least one of information recording and information reproduction with respect to a predetermined information storage medium is mounted;
- an arm portion for holding the head portion in such a manner that the head mounted on said head portion is disposed in the vicinity of or in contact with said information storage medium;
- an arm portion actuator for driving said arm portion to move the head mounted on the head portion held by the arm portion along said information storage medium;
- and
- a head portion actuator for rotating said head portion with respect to said arm portion and centering on a gravity center of the head portion,
- wherein said head portion actuator comprises:
- a driving portion provided with a lamination structure including at least one piezoelectric layer of a piezoelectric material and a plurality of electrode layers for holding the piezoelectric layer, and compressed/extended in a lamination direction of the lamination structure;
- and
- a holding portion for holding a plurality of said driving portions in an arrangement of rotation symmetry and nonlinear symmetry including the lamination direction in a predetermined common plane.
Dependencies are inferred from the claim text.