JP2002124048A - Disk head actuator device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a disk head actuator device which is high in the displacement of a laminated piezoelectric element, can avert the problem of strength and is high in the accuracy of displacement. SOLUTION: This device has a main actuator for largely displacing a timing head and an actuator for finely adjusting a head position. An ultrasonic motor 9 is used as an auxiliary drive source for fine adjustment. The timing head 1 is moved in the circumferential direction of a disk by the ultrasonic motor 9.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk recording / reproducing apparatus such as a hard disk drive or an optical disk for moving a head for recording / reproducing data in a radial direction of the disk to position the head at a target position. The present invention relates to a head actuator device.

[0002]

2. Description of the Related Art Small hard disk drive (HDD)
Are used as built-in external storage devices of notebook personal computers. In recent years, there has been an increasing demand for a small-sized and large-capacity HDD with the improvement in the performance of personal computers. In order to increase the storage capacity of the HDD, it is necessary to increase the track density and the linear recording density of the disk as a recording medium to increase the recording density of the disk.
With the increase in the recording density, a technique of positioning the head at a target position (track) to be accessed on the disk with high accuracy becomes important. Similar positioning technology is also required for optical disks.

As such a positioning technique, there is a method including a main actuator section for largely displacing and an auxiliary actuator section as an auxiliary drive source for performing fine adjustment.

A voice coil motor is used for the main actuator, and a method using two laminated piezoelectric elements is used as a sub-actuator. Examples of using two laminated piezoelectric elements are disclosed in Japanese Patent Application No. 1-49585 (see FIG. 3) and Japanese Patent Application No. 1-253523 (see FIGS. 4 (a) and 4 (b)). Technology (hereinafter, referred to as first and second conventional technologies, respectively), and papers published in the Journal of the Japan Society of Applied Magnetics, Vol. 18, No. 4, (1994) P863-868 (see FIG. 5). (Hereinafter, referred to as a third conventional technique) is known.

[0005] Here, the names of the constituent elements in FIGS. 3 to 5 will be described. 3 and 4, reference numeral 1 denotes a head on which a magnetic or optical module is mounted, 2 denotes a head support spring mechanism, 3a and 3b denote cutout structures, 4a and 4b denote laminated piezoelectric elements, 5 denotes a center member, and 6 denotes an access arm. Is shown.
In FIG. 4B, reference numeral 7 denotes a slit, and 8 denotes a punched round hole. In FIG. 5, 9 indicates a head mount, and 10 indicates a hinge.

In any of the above-described prior arts, the position of the head on which the magnetic or optical module is mounted is finely adjusted by alternately expanding and contracting the laminated piezoelectric elements. Fine adjustment of the head position requires a displacement on the order of μm, and the higher the recording density, the higher the positioning accuracy. Also, as a disk head actuator device,
From the demand for miniaturization of HDDs and optical disk devices, it is desired that the HDDs and optical disks be as small as possible and have sufficient strength to support the head.

That is, in a disk head actuator device that supports a head on which a magnetic or optical module for reading / writing data from / on a recording medium is mounted, an auxiliary drive source for finely adjusting the head position has conventionally been used. This is a method using a laminated piezoelectric element as noted.

[0008]

However, when a laminated piezoelectric element is used, there are some problems to be solved as follows.

First, since the displacement of the laminated piezoelectric element is small,
In order to obtain a sufficient displacement, it is necessary to increase the number of layers or provide a displacement enlarging mechanism. For example, the first prior art described above (the technology disclosed in Japanese Patent Application No. 1-49585) and the second prior art described above (Japanese Patent Application No. 1-2031).
523) has a structure in which the number of layers must be increased in order to obtain a displacement on the order of μm, although not mentioned in the text of the patent.
Increasing the number of layers leads to an increase in the size of the element.

In the third prior art (the technique disclosed in a paper published in Journal of the Japan Society of Applied Magnetics, Vol. 18, No. 4), an eight-fold displacement magnifying mechanism is provided. However, providing the displacement enlarging mechanism leads to an increase in the size of the disk head actuator device. Therefore, high-speed operation is hindered due to an increase in weight.

Second, since the element is easily bent, it is difficult to secure the strength of the actuator device. In particular, as the head actuator arm becomes smaller, the laminated piezoelectric element is also required to be smaller and thinner, and sufficient strength cannot be obtained with the element alone. In the first and second prior arts described above, the structure is such that the strength is maintained by the center member 5.
Since the center member itself has a low spring property, it is necessary to perform a difficult process such as introducing a cutout structure or making a slit and a punched round hole in the center member so as not to hinder the displacement of the laminated piezoelectric element.

Third, when manufacturing a laminated piezoelectric element,
Displacement of the element varies due to variation in cutting, which leads to variation in alignment when used as auxiliary driving means. As the recording density increases, the accuracy of alignment is required, and the influence of variations in elements increases.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a disk head actuator device in which the displacement of a laminated piezoelectric element is large, the problem of strength can be avoided, and the displacement accuracy is high. .

[0014]

SUMMARY OF THE INVENTION The present invention has been devised in order to solve the above-mentioned problems, and has a head for recording and reproducing a disk mounted thereon, and is moved in a radial direction of the disk to be positioned at a target. Head actuator device for a disk recording / reproducing apparatus for driving, comprising: a main drive source for driving a head in a range from an inner circumference to an outer circumference of a disk; and an auxiliary drive source for finely adjusting a position on the disk. In the device, a disk head actuator device is configured by using an ultrasonic motor as an auxiliary drive source.

[0015]

In the disk head actuator device,
By using an ultrasonic motor as the auxiliary driving means, a sufficient head displacement can be produced without providing a displacement enlarging mechanism.

The problem that the element in the laminated piezoelectric element is easily bent can be solved, and the problem of securing the strength of the actuator device can be solved.

Further, in the manufacturing process of the laminated piezoelectric element,
The problem of variation in displacement due to variation in cutting can also be solved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a disk head actuator device according to the present invention will be described below with reference to the drawings. FIG. 1 shows a structure of a disk head actuator device according to an embodiment of the present invention. FIG. 1 is a top view of the disk actuator device. Reference numeral 1 denotes a head on which a magnetic or optical module is mounted, 2 denotes a head supporting spring mechanism, 9 denotes an ultrasonic motor, and 10 denotes a voice coil motor as a main drive source. Voice coil motor 1
The position is set to be large at 0, and fine adjustment is performed by the ultrasonic motor 9.

FIG. 2 is a schematic view of the peripheral portion of the ultrasonic motor. 11a is the rotor of the ultrasonic motor, and 11b is the stator. The ultrasonic motor includes a rotating rotor 11a and a vibrating stator 11b. Stator 1
Numeral 1b is made of an elastic material such as phosphor bronze, and polarized piezoelectric ceramics (not shown) is attached to a lower portion with an adhesive. Aluminum was used for the rotor 11a. The rotor 11a may also be made of a lightweight aluminum alloy. The rotor 11a is bonded to a head support spring mechanism (not shown). The access arm, the rotor, the stator, and the head support spring mechanism are continuously connected through rivets.

When a voltage is applied to the piezoelectric ceramics, the stator vibrates to generate a traveling wave. Accordingly, the rotor 11
a rotates in the direction opposite to the traveling wave. In order to invert the voltage in the opposite direction, the phase of the voltage may be inverted. The piezoelectric ceramic causes the stator 11b to vibrate and the rotor 11a to rotate minutely to move the head on which the magnetic or optical module is mounted.

[0021]

As described above, according to the present invention, it is possible to provide a disk head actuator device capable of finely adjusting the magnetic head positioning. Further, it has become possible to avoid the problem of deflection of the element and the variation in displacement due to the variation in bending due to the variation in cutting, which are problems in the disk head actuator device using the laminated piezoelectric element.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a disk head actuator device according to an embodiment of the present invention.

FIG. 2 is a schematic view of a portion around an ultrasonic motor of the disk head actuator device of FIG. 1;

FIG. 3 is a schematic view of a conventional disk head actuator device.

4A and 4B are diagrams showing another conventional example, in which FIG. 4A is a schematic view of a disk head actuator device, and FIG. 4B is an enlarged view around a central member.

FIG. 5 is a schematic view of another conventional disk head actuator device.

[Description of Signs] 1 Magnetic head 2 Head support spring mechanism 3a, 3b Notch structure 4a, 4b Laminated piezoelectric element 5 Center member 6 Access arm 7 Slit 8 Punched round hole 9 Head mount 10 Hinge 11a Rotor 11b Stator

Continued on the front page F term (reference) 5D042 LA01 MA15 5D059 AA01 BA01 CA08 DA19 EA08 5D096 NN03 NN07 5H680 BB03 BB13 BB16 BB20 CC07 DD14 DD24 DD37 DD53 DD65 GG18 GG20 GG25

Claims (7)

[Claims] 1. A disk head actuator device of a disk recording / reproducing apparatus for mounting a head for recording / reproducing a disk, moving the head in a radial direction of the disk, and positioning the disk at a target, wherein the head is moved from an inner periphery of the disk. A disk head actuator device having a main drive source for driving a range up to an outer periphery and an auxiliary drive source for finely adjusting a position on a disk, wherein an ultrasonic motor is used as an auxiliary drive source. . 2. The disk head actuator device according to claim 1, wherein said ultrasonic motor comprises a rotating rotor and a vibrating stator. 3. The stator is made of an elastic body, and polarized piezoelectric ceramics is adhered to a lower portion thereof with an adhesive, and the rotor is made of a lightweight material and is adhered to a head supporting spring mechanism. 3. The disk head actuator device according to claim 2, wherein: 4. When a voltage is applied to the piezoelectric ceramics, the stator vibrates to generate a traveling wave, and the rotor rotates minutely in a direction opposite to the traveling wave, whereby the magnetic or optical module is mounted. 4. The disk head actuator device according to claim 3, wherein the disk drive moves. 5. The disk head actuator device according to claim 3, wherein said elastic body is phosphor bronze. 6. The disk head actuator device according to claim 3, wherein the material of the rotor is aluminum. 7. The disk head actuator device according to claim 3, wherein the material of the rotor is an aluminum-based alloy.