Actuator and magnetic head device

Abstract

An actuator includes a piezoelectric bimorph including a pair of piezoelectric elements and an intermediate electrode provided between the piezoelectric elements, a conductive fastening member for fastening fixed ends of the piezoelectric elements to a base having a ground potential, and a contact member to which a predetermined voltage is applied. The contact member is in contact with the intermediate electrode.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an actuator according to an embodiment of the present invention, and FIG. 1B is a perspective view of the principal part of the actuator;

FIG. 2 is a perspective view of an actuator according to another embodiment of the present invention;

FIG. 3 is a perspective view of an actuator according to a further embodiment of the present invention;

FIG. 4 is a perspective view of an actuator according to a still further embodiment of the present invention;

FIG. 5 is a perspective view of an actuator according to a still further embodiment of the present invention;

FIG. 6 is a perspective view of an actuator according to a still further embodiment of the present invention;

FIG. 7 is a perspective view of the principal part showing a state in which the actuator shown in FIG. 4 is mounted on a rotary drum;

FIG. 8 is a perspective view showing a state in which a plurality of actuators according to any of the embodiments are mounted on the rotary drum;

FIG. 9 is a side view of the principal part of a linear-type magnetic head device to which any of the embodiments of the invention is applied;

FIG. 10 is a perspective view of a known rotary drum;

FIG. 11 is an explanatory view showing the arrangement of a magnetic tape and a rotary drum in a known magnetic head device;

FIG. 12 is an explanatory view of tracks provided on the magnetic tape;

FIG. 13 is an explanatory view showing the arrangement of the magnetic tape and a magnetic head in the known magnetic head device;

FIG. 14 is an explanatory view showing track offset on the magnetic tape;

FIG. 15 is a sectional side view of an example of a known actuator;

FIG. 16 is an explanatory view showing displacement of the known actuator;

FIG. 17 is a perspective view of an example of a magnetic head device including the known actuator;

FIGS. 18A(a) and 18B(a) are explanatory views showing polarizing directions in driving methods for a piezoelectric bimorph, and FIGS. 18A(b) and 18B(b) are equivalent circuit diagrams of driving power sources.

FIG. 19 is an amplitude-voltage characteristic view in the driving methods for the piezoelectric bimorph; and

FIG. 20 is a perspective view of another embodiment of a known actuator.

Claims

1. An actuator comprising: a piezoelectric bimorph including a pair of piezoelectric elements, and an intermediate electrode provided between the piezoelectric elements;a conductive fastening member for fastening fixed ends of the piezoelectric elements to a base having a ground potential; anda contact member to which a predetermined voltage is applied, the contact member being in contact with the intermediate electrode.

2. The actuator according to claim 1, wherein a head chip having a magnetic head is bonded to a movable end of at least one of the piezoelectric elements.

3. The actuator according to claim 1, wherein the base is a rotary drum.

4. The actuator according to claim 1, wherein the base is a magnetic head body opposing a linear tape on which recording and reproduction are performed in a linear manner.

5. A magnetic head device comprising an actuator, wherein the actuator includes: a piezoelectric bimorph including a pair of piezoelectric elements, and an intermediate electrode provided between the piezoelectric elements;a conductive fastening member for fastening fixed ends of the piezoelectric elements to a base having a ground potential; anda contact member to which a predetermined voltage is applied, the contact member being in contact with the intermediate electrode.