JP2000173202A - Head positioning mechanism to actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head positioning mechanism of actuators devised to reduce the packaging height of the actuators of a two stage type for exactly positioning a disk device accompanying an increase in the recording density of a disk, to enable the packaging in a narrow space and to make possible to assure the necessary generating power of piezoelectric elements. SOLUTION: This head positioning mechanism is the actuators of the two stage type consisting of the sub-actuator part 10 for microdriving of a head supporting mechanism by the piezoelectric elements and the main actuator part 1 for driving an access arm 2 mounted with the sub-actuator part, in which the sub-actuator part is composed of an actuator spring 11 consisting of one steel sheet and a pair of the piezoelectric elements 12a and 12b and the part of the actuator spring for mounting a pair of the piezoelectric elements is formed thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a positioning mechanism for an actuator for a recording / reproducing head in a disk device such as a magnetic disk device and an optical disk device.

[0002]

2. Description of the Related Art In recent years, in a magnetic disk drive or the like, the recording density in the radial direction (track direction) of the disk has been increasing with the increase in the recording density on the disk, and a head (recording / recording) It is necessary to position the magnetic head or optical head for reproduction more accurately. Therefore, conventionally, in the actuator of the head, a main actuator section for moving the head with respect to a target track of the disk, and a head after the movement,
There has been proposed a head positioning mechanism including a sub-actuator section that finely moves on a target track and realizes accurate tracking.

FIGS. 3 and 4 show a conventional example of this head positioning mechanism. The head positioning mechanism is connected to an access arm 2 attached to a general swing type main actuator unit 1, a sub-actuator unit 10 for accurately following a target track, and a sub-actuator unit 10. The sub-actuator unit 10 is attached to the access arm 2 driven by the main actuator unit 1. The sub-actuator section 10 includes one actuator spring 11 and a pair of piezoelectric elements 12a and 12b bonded on the actuator spring 10.

In order to position the head on the target track, the head is first moved to the target track by the main actuator part 1 and then the sub-actuator section 10 is moved.
By applying a drive voltage to the pair of piezoelectric elements 12a and 12b and displacing them in opposite directions, the head support mechanism 3 is slightly swung right and left to accurately follow the target track.

[0005]

However, in the conventional head positioning mechanism as described above, the actuator
Since the piezoelectric elements 12a and 12b are bonded on the spring 11, the thicker the piezoelectric element is, the thicker the sub-actuator portion is at that portion. Anyway,
Since the generated force of the piezoelectric element is proportional to the cross-sectional area of the portion, it is necessary to increase the thickness of the piezoelectric element in order to obtain a sufficient driving force. In this case, a two-stage actuator (2 It is said that the head is positioned between two disks, and the target track is accessed by swinging), so that the mounting height increases, and mounting in a narrow space (a gap between two disks) becomes difficult. There was a problem.

That is, since the piezoelectric elements 12a and 12b are bonded on the actuator spring 11, the access arm 2 must be thickened so that the piezoelectric elements 12a and 12b do not interfere with each other.
The interval of b must be widened.

The present invention has been made based on the above circumstances. It is an object of the present invention to provide a two-stage type actuator for accurate positioning in a disk drive along with an increase in the recording density of a disk. It is an object of the present invention to provide a head positioning mechanism for an actuator, in which the mounting height is reduced and mounting in a narrow space is enabled, and the device is devised so as to secure a necessary generation force of a piezoelectric element.

[0008]

Therefore, a head positioning mechanism according to the present invention comprises a sub-actuator section for finely driving a head support mechanism by a piezoelectric element and a main actuator section for driving an access arm on which the sub-actuator section is mounted. Wherein the sub-actuator portion is constituted by an actuator spring made of a single steel plate and the pair of piezoelectric elements, and the portion of the actuator spring to which the pair of piezoelectric elements is attached is thinned. The configuration is as follows.

Therefore, even if a sufficient thickness is secured on the piezoelectric element so that the required generating force can be obtained, the head supporting mechanism can be formed by thinning the mounting portion of the actuator spring for bonding the piezoelectric element. Since the entire mounting height can be reduced, mounting in a narrow space (inter-disk space) is possible as a two-stage actuator.

[0010]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. Referring to FIGS. 1 and 2, here, a general two-stage type actuator includes an access arm 2 attached to a main actuator unit 1 and a sub-actuator unit 10 for accurately following a target track. , Sub-actuator section 10
The sub-actuator section 10 is attached to the access arm 2.

The sub-actuator section 10 is composed of one actuator spring 11 and a pair of piezoelectric elements 12a and 12b adhered on the actuator spring 10.
The mounting portion 13 of the piezoelectric element, which is a portion to which the piezoelectric elements 12a and 12b are bonded, is attached in the thickness direction of the actuator spring 11 by a method such as chemical etching.
Work up to approximately half the thickness. At this time, the size of the piezoelectric element mounting portion 13 is determined in consideration of the variation in the size of the bonded piezoelectric elements 12a and 12b.

The head support mechanism 3 is supported on the distal end side of the sub-actuator section 10 and connected at its base end to one end of the pair of piezoelectric elements 12a and 12b. The elements 12a and 12b are connected to the thinned portion 13 at the other end.

In such a configuration, the piezoelectric elements 12a, 1
2b, the mounting portion of the actuator spring 11 is thinned in the plate thickness direction, and the piezoelectric elements 12a, 12
Since b is bonded, the piezoelectric elements 12a and 12b hardly interfere with each other, and it is not necessary to make the access arm 2 thick, so that the space between the disks 20a and 20b can be maintained at a required small value.

[0014]

The head positioning mechanism according to the present invention is of a two-stage type comprising a sub-actuator for finely driving the head support mechanism by a piezoelectric element and a main actuator for driving an access arm on which the sub-actuator is mounted. In the actuator, the sub-actuator section is constituted by an actuator spring made of a single steel plate and a pair of piezoelectric elements, and the pair of piezoelectric elements is attached to the sub-actuator section so that the actuator spring portion is thinned. As a result, the mounting height of the entire head support mechanism can be reduced, and mounting in a narrow space between the disks is possible.

[Brief description of the drawings]

FIG. 1 is a plan view showing an embodiment of the present invention.

FIG. 2 is also a side view.

FIG. 3 is a plan view of a conventional head positioning mechanism.

FIG. 4 is also a side view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Main actuator part 2 Access arm 3 Head support mechanism 10 Sub actuator part 11 Actuator spring 12a, 12b Piezoelectric element 13 Piezoelectric element mounting part 20a, 20b Disk

Claims (2)

[Claims] 1. A two-stage type actuator comprising: a sub-actuator for finely driving a head support mechanism by a piezoelectric element; and a main actuator for driving an access arm on which the sub-actuator is mounted. A head comprising: an actuator spring made of a single steel plate; and a pair of piezoelectric elements, wherein a portion of the actuator spring for mounting the pair of piezoelectric elements is formed thin. Positioning mechanism. 2. The head support mechanism is supported at a distal end side of a sub-actuator part, and is connected to one end of the pair of piezoelectric elements at a base end thereof. The head positioning mechanism according to claim 1, wherein an end is connected to the thinned portion.