JP3338359B2 - Storage device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a storage device, and more particularly, to a storage device capable of realizing high-speed and high-resolution access.

[0002]

2. Description of the Related Art A conventional storage device, for example, a magnetic disk device 700 (HDD) as shown in FIG.
Floating head mechanism 7 provided with magnetic head 702 at the tip of
03, a carriage 705 which is supported by the swing shaft 704 and on which the floating head mechanism 703 is mounted, and a VCM (Voice Coil Moter) 7 provided on the opposite side of the magnetic head 702.
06. The swing shaft 704 is configured by a rolling bearing. By energizing the VCM 706, the magnetic head 702 swings about the swing shaft 704. The magnetic head 702 includes a rotating magnetic disk 70.
7 surface.

[0003] At present, the recording density per unit area in a storage device is increasing at an accelerating rate. Until now, the increase in recording density has been about 25% per year, but in recent years it has reached about 60%. Accordingly, a head positioning mechanism that enables high-speed and high-resolution access is required. In response to these requirements, for example, a technique for reducing the translational force acting on the pivot shaft by using two VCMs, a technique using a two-stage actuator for coarse movement and fine movement, and the like have been developed.

[0004]

However, in realizing high-speed and high-resolution access, the conventional storage device 700 has a problem in that the entire device vibrates due to a seek reaction force, and seek time is increased. .

Further, since the movement of the ball of the bearing used for the swing shaft 704 is different between reciprocation, there is a problem that a non-linear behavior occurs and affects positioning accuracy. These problems are obstacles to realizing high-speed and high-resolution access of the storage device.

[0006] These problems occur not only in the magnetic disk device 700 but also in the optical disk device.
For example, in a magneto-optical disk device 800 as shown in FIG. 7, a driving mechanism 803 including a magnetic circuit 801 and a driving coil 802 and a guide mechanism 806 including a rail 804 and a rolling bearing 805 form an optical head positioning mechanism 807. With this configuration, the vibration of the entire apparatus due to the seek reaction force cannot be prevented. Further, since the drive mechanism 803 and the guide mechanism 806 are required, there is a problem that the size of the apparatus becomes large.

It is an object of the present invention to provide a compact storage device capable of realizing high-speed and high-resolution access.

[0008]

In order to achieve the above object, a storage device according to a first aspect of the present invention has a storage medium and a plurality of beam portions which are fixed at one end and free at the other end. A drive unit provided with a piezoelectric body for each unit; and a head unit located on the drive unit so as to be in contact with the beam unit and acquiring data recorded in the storage medium.

When a piezoelectric body is provided on the beam and a voltage is applied to the piezoelectric body, the beam vibrates. The vibrated beam portion comes into contact with the head portion, and the head portion moves due to a lateral component force. If such a beam is provided in both directions, the head can be moved in both directions. A voltage having a resonance frequency is applied to the beam. The moving speed and the resolution are determined by such conditions as the frequency and the amplitude of the beam. In this configuration, only the head portion is directly moved.

Next, a storage device according to a second aspect of the present invention has a storage medium and a plurality of beam portions having one end fixed and the other end free and bidirectionally, and an arc-shaped drive in which a piezoelectric body is provided for each beam portion. Unit, a head unit for acquiring data recorded on the storage medium, and having substantially the same length as the arc radius of the driving unit, one end of which is fixed to the center of the arc, and the head unit is provided at the other end. And a suspension arm for applying a load to the head.

The head section moves on the drive section by the action of the beam section. The head section draws an arc with the radius of the suspension arm. The suspension arm applies a load to the head. On the other hand, the head unit obtains a floating force by rotating the storage medium. Due to the balance between the load weight and the levitation force, a levitation gap is generated between the storage medium and the head unit.

A storage device according to a third aspect of the present invention comprises a storage medium, a head for obtaining data recorded on the storage medium, and a plurality of beams fixed at one end and free at the other end. And a drive unit having a guide unit for guiding the head unit while providing a piezoelectric body for each of the beam units.

The head is moved by the action of the beam while being guided by the guide. The shape of the guide portion may be a curve or a straight line. Further, the guide portion may be formed in a groove shape and the head portion may be loosely fitted, or the guide portion may be formed like a dovetail groove to restrain the head portion. It does not matter whether the head unit and the storage medium are in contact or not.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. The present invention is not limited by the embodiment.

(First Embodiment) FIG. 1 is a schematic assembly diagram showing a magnetic disk drive according to a first embodiment of the present invention. The magnetic disk device 100 includes a magnetic disk 11
And a positioning mechanism 2 for positioning the magnetic head 21. The spindle mechanism 1 and the positioning mechanism 2 are incorporated in a base (not shown).

The spindle mechanism 1 has a structure in which a magnetic disk 11 is bolted to a rotating shaft 12 of a DC motor incorporated in a base. The magnetic disk 1 may be either one in which a magnetic recording layer is formed by applying an oxide on the disk base surface or one in which a magnetic material is sputtered. It is preferable that the magnetic layer of the magnetic disk 1 be thin and have high coercive force, and that the magnetic material particles be fine and the surface be uniform.

In the positioning mechanism 2, a suspension arm 22 for holding the magnetic head 21 and a support arm 23 for supporting the suspension arm 22 constitute a flying head mechanism. The support arm 23 is provided on the ring body 24. The ring body 24 is provided with an arc-shaped drive unit 25. The radius of the arc is equal to the length of the suspension arm 22. As the magnetic head 21, any of a ferrite head, a MIG (Metal In Gap) head, a thin film head, and an MR (Magneto Resistive) head may be used. MR head is suitable for high recording density.

The drive section 25 has a structure in which a plurality of beams 26 which are fixed at one end and are free at the other end are formed in each direction of the support 27, and a piezoelectric element 28 is attached to the back surface of these beams 26. The wiring 29 is formed on the back surface of the support 27.
The power supply 4 supplies power to the piezoelectric element 28 via the wiring 29. The seek / following control unit 5
Controls the supply voltage based on a servo signal from the magnetic head 21. The magnetic head 21 includes a support 27
Is located in contact with the upper surface of the beam portion. The magnetic head 2
Although 1 also contacts the magnetic disk 11, it floats by air film lubrication when the magnetic disk rotates, so that it mainly comes into contact with the beam side.

The driving section 25 is manufactured by using a photofabrication technique such as etching. By using a non-machining process, deformation, stress, and mechanical stress generated at the time of working formation can be eliminated, and function and reproducibility are stabilized. A metal material such as stainless steel and beryllium copper, which has excellent spring properties and can be processed with high precision by a process, a silicon-based material, or a composite material thereof is used as a structural material of the driving unit 25.

The piezoelectric element 28 is a material exhibiting a characteristic that a stress or displacement is generated according to an applied voltage, a resonance phenomenon is generated according to the frequency of the applied voltage, and a voltage is generated according to the applied pressure. . In the piezoelectric element 28 of this example,
A thin film lead zircon titanate having a high piezoelectric constant is used.
Further, barium titanate, lithium niobate, lead zirconate titanate, or the like may be used. Also, instead of these piezoelectric ceramics, a functionally graded material or lithium niobate can be used.

The lower surface of the magnetic head 21 (on the drive unit side)
Is provided with a sliding portion (not shown). In the sliding part,
Use a material that has a large friction coefficient, has excellent wear resistance, and can maintain a stable friction coefficient. For example, the sliding portion is subjected to an oxide film treatment. Further, in the sliding portion, a cellulosic fiber,
A carbon fiber, a composite material of whisker and phenol resin, or a composite material of polyimide resin and polyamide resin may be used.

The piezoelectric element 28 spread on the beam 26
Is formed by a thin film forming process. This is because it is suitable for mass production. In addition, because the size of the beam portion 26 is small, the manufacture is easy. Note that the beam 26 and the piezoelectric element 28 may be integrated by bonding. The bonding interface at this time must be very thin and hard, tough, and have a small resistance value near the resonance frequency after bonding. For example, a polymer adhesive represented by hot melt and epoxy resin is used as the adhesive.

The beam 26 is formed of one piezoelectric element 2
8 is a unimorph type, but a bimorph type using two piezoelectric elements or a multimorph type using four or more piezoelectric elements may be used. Further, the shape of the beam portion 26 is not limited to a simple beam shape as shown in FIG. For example, a peak or a protrusion may be provided at the tip of the beam, or a shape having a constriction may be provided.

Next, the operation of the storage device 100 will be described. First, the operating principle of each beam unit is shown in FIG.
By applying a drive voltage of a specific frequency to the piezoelectric element 28, the piezoelectric element 28 expands and contracts in the direction of arrow A in the figure.
Due to this expansion and contraction, the beam 26 vibrates in the direction of arrow B in the figure.
When the beam 26 vibrates, the tip 26 a of the beam 26 comes into contact with the magnetic head 21. The contact direction is the magnetic head 21
The magnetic head 21 is moved by the force component Ch in the lateral direction because it is not perpendicular to the direction but in the direction indicated by the arrow C in the figure. Further, the specific frequency is matched with a natural frequency according to the size and shape of the beam portion 26. This is because the maximum amplitude of the beam portion can be obtained by setting the frequency near the resonance frequency.

Next, the operation of the driving section will be described.
As shown in FIG. 3, the magnetic head 21 is moved by vibrating the plurality of beams 26. One beam part 26
When r is vibrated, the magnetic head 21 moves inward. When the beam 26l on the other side is vibrated, the magnetic head 21 moves outward. Magnetic head 2
1 is supported by the suspension arm 22, but since the suspension arm 22 has high elasticity, the suspension arm 22 can be moved in an arc around the root of the suspension arm 22. The seek and following operations of the magnetic head 21 are controlled by a seek / following control unit 5.

(Embodiment 2) FIG. 4 is a perspective view showing a positioning mechanism of a storage device according to Embodiment 2 of the present invention. In the positioning mechanism 202 of the storage device according to the second embodiment, the magnetic head 221 is moved along the guide portion 222 without using the suspension arm as in the first embodiment.
To move. The guide portions 222 are provided on both sides of the support 223. A plurality of beams 224 are formed on the support 223 in both directions.
4, a piezoelectric element 225 is spread on each of the driving units 226.
Is composed. The drive section 226 is provided so as to project from the ring body 227. The guide portion 222 is formed together with the support 223 by using a photofabrication technique such as etching. The height of the guide portion 222 is set slightly lower than the height of the magnetic head 221. The magnetic disk, power supply, and other components are the same as the storage device 1 according to the first embodiment.
Since it is almost the same as 00, the description is omitted. In such a configuration, the magnetic head 221 may be levitated from a magnetic disk (not shown), or may be in a pseudo contact or contact state. The storage device according to the second embodiment has a simple configuration and is easy to manufacture.

(Embodiment 3) FIG. 5 is a schematic perspective view showing a configuration of a positioning mechanism of a storage device according to Embodiment 3 of the present invention. This storage device is a magneto-optical disk device, and an optical head 403 having an objective lens 402 is attached to a movable portion 401. The movable unit 401 is a driving unit 4
04, and the sliding direction is regulated by the guide portion 405. A plurality of beams 406 are provided bidirectionally on the upper surface of the driving unit 404. Each of the beam portions 406 is provided with a piezoelectric element 407. Piezoelectric element 4
07 receives power supply from a power supply (not shown). The guide 405 is formed integrally with the case 408, and an optical system 409 is installed at an end of the case 408.

At the time of recording, a laser beam emitted from the optical system 409 enters through the window 410 of the movable unit 401,
The light is refracted by a prism (not shown) provided in the movable portion 401. Then, the light is converged by the objective lens 402 and irradiated on the magneto-optical disk 411. On the magneto-optical disk 411, the magnetic pole is inverted by the heat of the laser beam, and information is recorded. On the other hand, at the time of reproduction, the laser beam irradiated by the same route is introduced again into the optical system 409. Since the vibrating surface of the laser reflected light rotates due to the Kerr effect in the magnetic pole reversal portion, the rotation angle is measured to reproduce the information.

A voltage is applied to the piezoelectric element 407 to
By vibrating 6, the optical head 401 is moved. The operation principle of each beam unit is as described in the first embodiment. Power is supplied to the piezoelectric element 407r on one side to
When 06r is vibrated, the optical head 401 moves inward. When the piezoelectric element 407l on the other side is energized to vibrate the beam portion 4061, the optical head 401 moves outward. The optical head 401 includes the guide unit 40
Move along 5. Further, the frequency of the voltage applied to the piezoelectric element 407 is matched with the natural frequency according to the size and shape of the beam portion 406.

[0030]

As described above, the storage device of the present invention (Claim 1) has a storage medium and a plurality of beams, one end of which is fixed and the other end is free, in each direction. A drive unit provided with a body, and a head unit located on the drive unit so as to contact the beam unit and acquiring data recorded on the storage medium, and the head unit is directly moved. So the seek reaction decreases. Also, no rolling bearing is required. For this reason, high-speed and high-resolution access becomes possible. Further, since no VCM or the like is required, the device becomes compact.

Next, a storage device according to the present invention (Claim 2)
Has a storage medium, a plurality of beam portions that are fixed at one end and free at the other end, bidirectionally, an arc-shaped drive unit provided with a piezoelectric body for each of the beam portions, and data recorded on the storage medium. A head section to be obtained, and a suspension arm having substantially the same length as the arc radius of the driving section, one end of which is fixed to the center of the arc, and the other end provided with the head section to apply a load to the head section. Since the head is moved directly, the seek reaction force is reduced. Further, the head portion is swung by the suspension arm without requiring a rolling bearing. For this reason, high-speed and high-resolution access becomes possible. Further, since no VCM or the like is required, the device becomes compact.

Next, a storage device according to the present invention (claim 3)
Has a storage medium, a head unit for acquiring data recorded on the storage medium, a plurality of beam portions fixed at one end and free at the other end, and a piezoelectric body is provided for each beam portion, A drive unit having a guide unit for guiding the head unit, and the head unit is directly moved, so that the seek reaction force is reduced. Further, the head portion is merely guided by the guide portion without using a rolling bearing. For this reason, high-speed and high-resolution access becomes possible. Further, since no VCM or the like is required, the device becomes compact.

[Brief description of the drawings]

FIG. 1 is a schematic assembly diagram showing a magnetic disk drive according to Embodiment 1 of the present invention.

FIG. 2 is an explanatory view showing the operation principle of each beam unit.

FIG. 3 is an explanatory diagram illustrating an operation of a driving unit.

FIG. 4 is a perspective view showing a positioning mechanism of a storage device according to Embodiment 2 of the present invention.

FIG. 5 is a schematic perspective view illustrating a configuration of a positioning mechanism of a storage device according to Embodiment 3 of the present invention.

FIG. 6 is a perspective view showing the structure of a conventional magnetic disk drive.

FIG. 7 is a perspective view showing the structure of a conventional magneto-optical disk device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 magnetic disk drive 1 spindle mechanism 11 magnetic disk 12 rotating shaft 2 positioning mechanism 21 magnetic head 22 suspension arm 23 support arm 24 ring body 25 drive unit 26 beam unit 27 support unit 28 piezoelectric element 29 wiring

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoko Suzuki 1-8-1 Nakase, Mihama-ku, Chiba-shi, Chiba Seiko Instruments Inc. (56) References JP-A 1-312223 (JP, A) JP-A 10 -31871 (JP, A) JP-A-3-1422763 (JP, A) JP-A-6-277624 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 21/02 601 H02N 2/00 H01L 41/09

Claims (3)

(57) [Claims] 1. A drive unit having a storage medium, a plurality of beam portions fixed at one end and free at the other end, and a driving unit provided with a piezoelectric body for each of the beam portions; and a head portion for acquiring data located on part is recorded in the storage medium, the beam which vibrates by applying a voltage to the piezoelectric element
The head contacts the head and the head
A storage device wherein the storage unit moves . 2. A storage medium, a plurality of beam portions having one end fixed and the other end free and having a bidirectional shape, an arc-shaped drive unit provided with a piezoelectric body for each of the beam portions, A head unit for acquiring certain data; a suspension arm having substantially the same length as the arc radius of the drive unit, one end of which is fixed to the center of the arc, and the other end provided with the head unit for applying a load to the head unit. with the door, said beam vibrates by applying a voltage to the piezoelectric element
The head contacts the head and the head
A storage device wherein the storage unit moves . 3. A storage medium, a head unit for acquiring data recorded on the storage medium, and a plurality of beam portions having one end fixed and the other end free, and a piezoelectric body is provided for each beam portion. the beam which oscillates together, and a drive unit having a guide portion for guiding the head portion, by applying a voltage to the piezoelectric element provided
The head contacts the head and the head
A storage device wherein the storage unit moves .