JPH04295679A - Levitation-type magnetic head device - Google Patents

Abstract

PURPOSE:To reduce the driving power of a piezoelectric element for a levitation- type magnetic head device. CONSTITUTION:A piezoelectric element 15 is attached to a slider 12 which holds a magnetic head element 11. It is driven at a frequency corresponding to a resonance mode for the slider. The slider is supported by nodes Na, Nb in the resonance mode.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a floating magnetic head device suitable for recording and reproducing hard disks.

0002

2. Description of the Related Art As is well known, in a hard disk drive, when the magnetic disk is stopped, the magnetic head comes into contact with the surface of the magnetic disk, and when the magnetic disk is rotating, the magnetic head slightly floats up and is separated from the magnetic disk. A floating magnetic head device is used in which an air layer is formed between the magnetic heads. Therefore, when starting or stopping the magnetic disk,
The magnetic head sometimes came into contact with the magnetic disk, damaging the disk.

In order to prevent damage to the magnetic disk as described above, it has conventionally been common practice to separate the magnetic head from the disk until the rotation of the magnetic disk stabilizes when starting or stopping the magnetic disk. However, as hard disk drives have become smaller and have larger capacities, the spacing between disks has become narrower, making it mechanically difficult to implement.

In order to solve this problem, the magnetic head can be operated even when the magnetic disk is not rotating by driving a piezoelectric element disposed on the surface facing the disk of the magnetic head device with an appropriate DC voltage or AC voltage. A floating magnetic head device is known that is slightly floating above the magnetic disk surface to prevent sliding contact with the magnetic head when starting or stopping the magnetic disk (Japanese Patent Publication No. 63-4274). (see publication).

[0005] Furthermore, a device in which the piezoelectric element is divided to enable adjustment of the flying height or correction of variations in the flying height in the radial direction of the disk is also disclosed in Utility Model Application Laid-Open No. 2-301 by the present applicant.
It is known from Publication No. 71.

First, with reference to FIG.
A floating magnetic head device according to Japanese Patent No. 30171 will be described. In FIG. 5, 10 indicates the magnetic head device as a whole. 11 is a magnetic head element; 12 is a sled-shaped holding member (slider); the magnetic head element 11 is held by one leg 13 of the slider 12;
4, it faces a magnetic disk (not shown). A pair of piezoelectric elements 15a and 15b are disposed in a recess between the legs 13 and 14 of the slider 12, and are bonded to the slider 12 on the opposite side from the magnetic head element 11.

Although not shown, piezoelectric elements 15a, 15
A pair of electrodes are provided on each of the electrodes b, and a suitable DC voltage or AC voltage is applied thereto to adjust the flying height or correct the variation in the flying height in the radial direction of the disk, as described above. The magnetic head device as described above is coupled to a rotating member (arm) (none of which is shown) via an elastic support piece (flexure) provided on the surface of the slider 12 opposite to the disk. .

[0008]

However, the conventional floating magnetic head device as described above has a problem in that a considerable amount of electric power is required to drive the piezoelectric element. With the increase in capacity as described above, a plurality of floating magnetic head devices are often incorporated into one hard disk drive. In this case, driving power becomes a more important issue.

In view of the above, an object of the present invention is to provide a floating magnetic head device that can reduce the driving power of the piezoelectric element.

0010

[Means for Solving the Problems] The present invention includes a magnetic head element 11, a holding member 12 that holds the magnetic head element and faces a magnetic disk, and a piezoelectric element 15 attached to the holding member. A floating magnetic head device in which a piezoelectric element is driven at a predetermined frequency to vibrate a holding member in a resonance mode, and the holding member is supported at nodes Na and Nb in the resonance mode. be.

[0011]

According to the present invention, the energy required to vibrate the holding member with the required amplitude is reduced, and the driving power of the piezoelectric element is reduced.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a floating magnetic head device according to the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 2 shows the overall structure of an embodiment of the present invention, and FIG. 1 shows the structure of the main parts. In both figures, parts corresponding to those in FIG. 5 described above are given the same reference numerals and redundant explanation will be omitted.

In FIG. 2, 10T indicates the entire magnetic head device of this embodiment. In this embodiment, a rectangular piezoelectric element 15, for example made of ferrite, is mounted with its longitudinal direction parallel to the scanning direction of the disk on the upper surface of the slider 12, made of for example ceramic or ferrite.

16 is a support member, for example, 50μ
It is formed by bending a steel plate with a certain thickness into a U-shape. Notches 16a and 16b corresponding to the piezoelectric elements 15 are provided on both sides of the support member 16, respectively, and both sides of the support member 16 are made perpendicular to the scanning direction of the disk.
The ends 16c, 16d, 16e, 16f are the slider 1
It is fixed to the top surface of 2.

One end 21a of an elastic support piece (flexure) 21 is fixed to the upper surface of the support member 16, and the other end 21b is in contact with the upper surface of the magnetic head device 10T.
is coupled to the arm 22 via the flexure 21.

Next, the operation of one embodiment of the present invention will be explained with reference to FIG. When the magnetic disk is started or stopped, it is driven by an appropriate alternating current voltage, and the piezoelectric element 15 expands and contracts in the longitudinal direction. As shown by chain lines in FIG. 1, the expansion and contraction of the piezoelectric element 15 causes the slider 12 to bend in the scanning direction of the disk and vibrate with both end surfaces in the scanning direction as free ends. In the middle of the slider 12 in the scanning direction, there are nodes Na and Nb with zero amplitude. In other words, the slider 12 vibrates in the scanning direction in a secondary mode.

In this embodiment, each end 1 of the support member 16
As the fixed positions of 6c to 16f, the nodes Na and Nb of the slider 12 as described above are selected, and the frequency of the drive signal is selected to be equal to the natural frequency (resonant frequency) of the secondary vibration mode, for example, about 100 kHz. The slider 12 is caused to resonate.

In this way, by exciting at the resonant frequency of the slider, the driving power required to obtain an amplitude of, for example, about 0.1 μ can be reduced by more than an order of magnitude from the conventional, for example, about 100 mW. can.

Next, another embodiment of the floating magnetic head device according to the present invention will be described with reference to FIGS. 3 and 4.

FIG. 3 shows the overall configuration of another embodiment of the present invention.
The configuration of the main part is shown in FIG. In both figures, parts corresponding to those in FIGS. 1, 2, and 5 are given the same reference numerals, and some explanations will be omitted.

In FIG. 3, 10R indicates the entire magnetic head device of this embodiment. In this embodiment, a rectangular piezoelectric element 15 is attached to the top surface of the slider 12 perpendicular to the scanning direction of the disk, and a support member 16
Each end portion 16c, 16d, 16e, 16f of the support member 16 is fixed to the upper surface of the slider 12 so that both side surfaces thereof are in the scanning direction of the disk. The rest of the configuration is the same as that shown in FIG. 2 above.

Next, the operation of the embodiment shown in FIG. 3 will be explained with reference to FIG. In this embodiment, piezoelectric element 1
5 is perpendicular to the scanning direction of the disk, and as the piezoelectric element 15 expands and contracts, the slider 12 bends in the radial direction of the disk, as shown by the chain line in FIG. It vibrates in secondary mode. Nodes Nc and Nd exist in the radial intermediate portion.

In this embodiment as well, each end 1 of the support member 16
6c to 16f are fixed to the nodes Nc and Nd of the slider 12 as described above, and the frequency of the drive signal is selected to be equal to the natural frequency of the secondary vibration mode, so that the slider 12 resonates and the desired vibration is achieved. The driving power can be significantly reduced.

In each of the above-described embodiments, the vibration of the slider has been explained as being in a secondary mode, but a tertiary or higher vibration mode may be selected. Further, by using a stacked piezoelectric element, a large amplitude can be obtained with a small driving voltage. Furthermore,
When a plurality of floating magnetic head devices are incorporated into one hard disk drive, the piezoelectric elements can be connected in series or in parallel to reduce the number of drive amplifiers used and to downsize the hard disk drive.

[0026]

[Effects of the Invention] As detailed above, according to the present invention,
A piezoelectric element is attached to the slider that holds the magnetic head element, and is driven at a frequency that corresponds to the resonance mode of the slider, and the slider is supported at the nodes of the resonance mode, so that the energy needed to vibrate the slider with the required amplitude is generated. Therefore, a floating magnetic head device is obtained in which the drive power of the piezoelectric element can be reduced.

[Brief explanation of drawings]

[FIG. 1] A side view showing the configuration of essential parts of an embodiment of a floating magnetic head device according to the present invention.

[Fig. 2] A perspective view showing the overall configuration of an embodiment of the present invention.

[Fig. 3] A perspective view showing the overall structure of another embodiment of the floating magnetic head device according to the present invention.

[Fig. 4] A front view showing the configuration of main parts of another embodiment of the present invention.

[Fig. 5] A perspective view showing an example of the configuration of a conventional floating magnetic head device.

[Explanation of symbols]

Claims (1)

[Claims] 1. A floating magnetic head device comprising a magnetic head element, a holding member that holds the magnetic head element and faces a magnetic disk, and a piezoelectric element attached to the holding member, wherein the piezoelectric element is A floating magnetic head device, characterized in that the holding member is driven at a predetermined frequency to vibrate in a resonance mode, and the holding member is supported at a node in the resonance mode.