JP3225510B2 - Magnetic head slider positioning mechanism - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a magnetic head positioning mechanism in a disk device such as a magnetic disk device or an optical disk device.

[0002]

2. Description of the Related Art The recording density of a magnetic disk drive is high BP.
Due to the introduction of I (Bit Per Inch) and high TPI (Track Per Inch), it is increasing at an annual rate of 60% or more. To increase the BPI, it is necessary to reduce the flying height of the head and use MR (Magneto Resist).
ive) Adoption of a magnetic head with high sensitivity such as a head or high-efficiency signal processing technology is required. In order to realize a high TPI, it is important to improve the positioning accuracy of the magnetic head. Becomes For example, 1G
At a recording density of b / in2, the track direction density is 8 kTPI or less, and the track pitch is about 3 to 4 μm, but to achieve a recording density of 10 Gb / in2 or more, the track density is 25 kTPI.
As described above, since the track pitch is 1 μm or less, the positioning accuracy of the magnetic head is required to be 0.1 μm or less (which is 10% of the track pitch).

FIG. 19 shows a conventional example of a magnetic head positioning mechanism (positioner) used in a magnetic disk drive.
This magnetic head positioning mechanism is called a rotary actuator system that drives the magnetic head to rotate in an arc shape, and includes a plurality of holder arms 11 and an arm block (carriage) 13 having a movable coil 12. Is rotatable in the direction of arrow A (see FIG. 19B). A magnetic head supporting mechanism 5 (suspension or HGA: Head Gimbal Assembly) that supports the slider 2 on which the magnetic head 1 is mounted is connected to the tip of the holder arm of the arm block 13 (FIGS. 19C and 19C). d)). Also,
The movable coil 12 installed at the other end of the arm block 13 is combined with an external fixed magnetic circuit 15 to
(Voice Coil Motor), a driving force is generated by applying a predetermined driving current to the movable coil 12, and the magnetic head supporting mechanism 5 is generated.
Is rotated in an arc trajectory in the seek direction (FIG. 19B: arrow A) to position the magnetic head 1 on a target track on the medium. The positioning operation referred to here includes a seek operation (tracking) for moving the magnetic head from an arbitrary track position to a target track position, and a follow operation (following) for keeping the magnetic head on the target track. Divided into

As described above, the conventional magnetic head positioning mechanism simultaneously drives a plurality of magnetic heads with one VCM, so that the positioning accuracy, especially the track following accuracy in following, is not sufficient, and the narrow track of 1 μm or less is used as described above. It is becoming impossible to cope with high TPI equipment that requires pitch. Therefore, research on a two-stage actuator for individually driving each magnetic head independently of carriage driving by the VCM is being conducted. These two-stage actuators can be roughly classified into three types depending on the parts to be individually driven. That is, a head element driving method for individually driving the magnetic head unit (FIG. 2)
0), a slider drive system for individually driving the slider unit (FIG. 21), and an HGA drive system for individually driving the magnetic head support mechanism (HGA) unit (FIGS. 22 and 23).

The head element driving method shown in FIG. 20 employs a micro-machine technology in which an electrostatic drive type linear actuator A2 having a comb-tooth structure is embedded in a slider A1. The yield is poor, and there is a drawback that the shock is easily displaced or destroyed when an impact is applied in the movable direction, so that it has not yet been put to practical use.
In FIG. 20, A3 is a magnetic head, and A4 is a magnetic head support mechanism (suspension).

The slider driving method shown in FIG. 21 has a structure in which a silicon micro-gimbal B1 and a planar electromagnetic driving piggyback microactuator B2 are combined. However, since the coil pattern layer for generating an induced magnetic field cannot be processed thickly. There is a problem that a sufficient driving force cannot be obtained.

Finally, the HGA driving method shown in FIGS. 22 and 23 is based on a force-acceleration type (high) depending on whether the generated force of the HGA driving actuator is proportional to the acceleration or displacement of the magnetic head. Compliance type: Fig. 2
2) and a force-displacement type (high stiffness: FIG. 23).

In the force-acceleration type (high compliance type) two-stage actuator shown in FIG. 22, a type in which a small VCM is constructed at an HGA junction and a magnetic head is rotationally driven by an electromagnetic force is mainstream. A cross-shaped leaf spring C1 and an I-shaped leaf spring (Japanese Patent Application No. 09-260680) are arranged in the bearing portion, and the HGA is rotated by bending the leaf spring by the driving force of the small VCM. In the case of this force-acceleration type two-stage actuator (small VCM type), a large driving stroke can be obtained with a relatively small current, but the rotational rigidity of the bearing spring (cross-shaped spring / I-shaped spring) cannot be increased. There is a problem that an actuator main resonance (axial rotation mode) appears in a low frequency band and the servo band is narrowed. Also, when a digital controller is used, unlike a force-displacement type two-stage actuator to be described later, a sensor for detecting the relative displacement between the first-stage and second-stage actuators is required, which complicates the system. There are also problems.

On the other hand, a force-displacement type (high stiffness type) two-stage actuator shown in FIG. 23 has a piezoelectric element D2 disposed at a joint position between a holder arm D1 and an HGA section D4, and utilizes an HGA section utilizing a piezoelectric effect. D4 is driven, and as shown in FIG.
1 is directly embedded in the tip of the holder arm D
A pair of parallel leaf springs D3 integrally formed at the tip of the pair 1
Are driven by the distortion of the piezoelectric element D2 to drive the HGA unit D4 attached to the tip end.

Recently, as shown in FIG. 24, a small actuator spring 8 is arranged between the holder arm and the HGA, and a pair of piezoelectric elements 16 are fixed thereon to flex the actuator spring 8. On the other hand, a type in which the HGA connected to the end is driven, and a type in which the HGA unit E2 is driven by using the thickness sliding vibration (1.5 mode) of the piezoelectric element E1 as shown in FIG. I have.

[0011]

SUMMARY OF THE INVENTION These force-displacement type 2
The stage actuator has the advantage that the servo system can be easily constructed, high-speed operation is possible, and the rigidity can be designed, so that the servo band can be widened. There is a disadvantage that the movable range is narrowed and the track following performance is limited. In such a case, in order to extend the drive range of the magnetic head, it is necessary to design the actuator spring so that the drive magnification (the drive amount of the magnetic head with respect to the displacement of the piezoelectric element) is increased. The support rigidity is reduced, and the impact resistance and long-term reliability (load / unload durability, etc.) are sacrificed. Further, since the generated force of the piezoelectric element is proportional to the cross-sectional area (and applied voltage) of the element section, it is necessary to increase the thickness of the piezoelectric element in order to obtain a sufficient driving force. The mounting height becomes large, and it becomes difficult to mount between narrow plates.

The present invention has been made based on the above-described circumstances, and an object of the present invention is to provide a magnetic disk drive having a high recording density exceeding 10 Gb / in2, for example, in which a track density of 25 kT
It is an object of the present invention to provide a high-speed and high-precision magnetic head positioning mechanism that can follow a narrow track pitch of PI or more (track pitch of 1 μm or less) and can secure a servo band of 3 kHz or more.

[0013]

A magnetic head positioning mechanism according to the present invention includes a magnetic head support mechanism and a two-stage actuator. The magnetic head support mechanism is configured to support a slider on which a magnetic head is mounted. 2 above
The stage actuator includes a fine actuator unit that displaces the magnetic head support mechanism by a small amount in the seek direction of the magnetic head, and a course actuator unit that displaces the fine actuator unit in the seek direction of the magnetic head by a voice coil motor. The fine actuator section comprises a thin plate-shaped actuator spring for supporting the magnetic head support mechanism and two piezoelectric elements, and a minute amount of the magnetic head support mechanism in a seek direction of the magnetic head. The displacement is
The driving is performed by generating a driving force on the two piezoelectric elements by alternately applying a voltage to the two piezoelectric elements, and elastically bending the actuator spring portion by the driving force. Comprises a first support portion supporting the magnetic head support mechanism, a second support portion supported by the course actuator portion, and a spring portion connecting between the first support portion and the second support portion. The spring part includes a center spring composed of one I-shaped leaf spring and two I-shaped leaf springs.
And a side spring made of a leaf spring of a shape,
The center spring extends in the central axis direction on a central axis in a longitudinal direction of the actuator spring,
The two side springs extend in a direction orthogonal to the central axis at a position sandwiching the central axis. Therefore, by applying a voltage alternately to the two piezoelectric elements, a driving force is generated in the two piezoelectric elements, and the actuator spring section is elastically bent by the driving force, thereby forming the fine actuator section. In this case, the magnetic head supporting mechanism, which is connected to the magnetic head, is minutely driven in the seek direction, and the respective magnetic heads are individually positioned and controlled, whereby a highly accurate track following operation (following) can be performed. Further, the magnetic head positioning mechanism of the present invention includes a magnetic head support mechanism and a two-stage actuator, wherein the magnetic head support mechanism is configured to support a slider on which a magnetic head is mounted, and the two-stage actuator includes a magnetic head. A fine actuator section for displacing the head support mechanism by a minute amount in the seek direction of the magnetic head; and a coarse actuator section for displacing the fine actuator section in the seek direction of the magnetic head by a voice coil motor. The actuator section is a thin plate-shaped actuator for supporting the magnetic head support mechanism.
A minute displacement of the magnetic head supporting mechanism in the seek direction of the magnetic head by applying a voltage to the two piezoelectric elements alternately includes a spring and two piezoelectric elements. The driving force is generated by elastically bending the actuator spring portion by the driving force.
A spring supports the first magnetic head supporting mechanism.
A first support portion, a second support portion supported by the coarse actuator portion, and a spring portion connecting between the first support portion and the second support portion, wherein the spring portion is a single I-shaped A center spring consisting of a leaf spring of
A side spring formed of two I-shaped leaf springs, wherein the center spring extends in the direction of the central axis on the central axis, and the two side springs include:
At a position sandwiching the central axis, the first axis extends in a direction intersecting the central axis such that an interval on the first support portion side is larger than an interval on the second support portion side. Therefore, by applying a voltage alternately to the two piezoelectric elements, a driving force is generated in the two piezoelectric elements, and the actuator spring section is elastically bent by the driving force, thereby forming the fine actuator section. Track driving operation (following) by finely driving the magnetic head support mechanism connected to the motor in the seek direction and controlling the positioning of each magnetic head individually.
It can be performed. Further, the magnetic head positioning mechanism of the present invention includes a magnetic head support mechanism and a two-stage actuator, wherein the magnetic head support mechanism is configured to support a slider on which a magnetic head is mounted, and the two-stage actuator includes a magnetic head. A fine actuator section for displacing the head support mechanism by a small amount in the seek direction of the magnetic head; and a coarse actuator section for displacing the fine actuator section in the seek direction of the magnetic head by a voice coil motor,
The fine actuator section has a thin plate-shaped actuator spring that supports the magnetic head support mechanism and two piezoelectric elements, and the minute displacement of the magnetic head support mechanism in the seek direction of the magnetic head is: The driving is performed by generating a driving force on the two piezoelectric elements by alternately applying a voltage to the two piezoelectric elements, and elastically bending the actuator spring portion by the driving force. A first support portion for supporting the magnetic head support mechanism;
A second support portion supported by the course actuator portion; and a spring portion connecting between the first support portion and the second support portion, wherein the spring portion is formed by two I-shaped leaf springs. A center spring and two side springs formed of two I-shaped leaf springs, and the two side springs are connected to a longitudinal center axis of the actuator spring at a position sandwiching the center axis. The two center springs extend in a direction orthogonal to each other, and the two center springs sandwich the center axis, are closer to the second support portion than the two side springs, and are more centered than the two side springs. It is characterized in that it extends in a direction perpendicular to the central axis at a position close to the axis. Therefore, by alternately applying a voltage to the two piezoelectric elements,
By generating a driving force on the two piezoelectric elements and elastically bending the actuator spring portion by the driving force, the magnetic head supporting mechanism connected to the fine actuator portion is minutely driven in the seek direction,
A highly accurate track following operation (following) can be performed by controlling the positioning of each magnetic head individually.

[0014]

Next, an embodiment of a magnetic head slider positioning mechanism according to the present invention will be described in detail with reference to the drawings. First, a first embodiment will be described with reference to the drawings. 1 (a), (b), (c1),
(C2) is a plan view, a side view, and the like showing the first embodiment.
It is a principal part side view, principal part top view. FIGS. 2A, 2B, and 2C are a plan view, a side view, and a plan view of an actuator spring showing details of the fine actuator unit according to the first embodiment. FIGS. 3A and 3B are perspective views showing the configuration of the first embodiment. FIGS. 4A and 4B are a plan view and a side view showing the structure and operation principle of the actuator spring portion. FIGS. 5A and 5B are plan views showing a driving method using a piezoelectric element. FIG. 6 (a), (b)
(C) is a displacement diagram showing a spring behavior during the operation of the fine actuator. FIG. 7 (a) and (b)
FIG. 3 is a graph (simulation) showing a displacement amount (distortion amount) of a piezoelectric element and a driving distance of a magnetic head, and a characteristic diagram showing vibration characteristics. FIG. 8A is a plan view of the actuator spring according to the first embodiment.

In FIG. 1, the magnetic head positioning mechanism includes a magnetic head support mechanism 5 and a two-stage actuator including a fine actuator section 6 and a course actuator section 7. The fine actuator section 6 is composed of an actuator spring 8 and a piezoelectric element 16, and is attached to a holder arm 11 constituting the course actuator section 7 at a holder arm swaging position 10 (corresponding to a second support section in the claims). Connected. Further, an arm block (carriage) 13 including a plurality of holder arms 11 has a movable coil 12 at one end thereof, and forms a VCM in combination with an externally fixed magnetic circuit (not shown) to form the course actuator section 7. I have.

On the other hand, as shown in FIGS. 2A and 2B,
The magnetic head support mechanism 5 includes a floating or contact type slider 2 on which the magnetic head 1 is mounted, a gimbal spring 3 for supporting the slider 2, and a load beam 4 for applying a pressing force to the slider 2. . The slider 2 is connected to the phi actuator 6 at a suspension caulking position 9 (corresponding to a first support in the claims) with the slider 2 facing the recording medium 26. Further, as shown in FIG. 2C, the actuator spring 8 of the fine actuator section 6 includes two long I-shaped side springs 17 between a suspension caulking position 9 and a holder arm caulking position 10. One short I-shaped center spring 1
8 is provided.

The center spring 18 is located on the center axis of the actuator spring 8 in the longitudinal direction, and the two side springs 17 are located at the center of the actuator spring 8 in the longitudinal direction with the center spring 18 interposed therebetween. They are arranged in series in a direction perpendicular to the axis. At this time, as shown in FIG.
A drive gap 25 is formed between the side spring 17 and the center spring 18 of the spring 8 and the holder arm swaging position 9. Then, as shown in FIG. 3A, a pair of rectangular parallelepiped piezoelectric elements 16 are formed so as to straddle the drive gap 25 so as to extend over the actuator spring 8.
Are arranged in parallel with a direction along the longitudinal axis with respect to the central axis in the longitudinal direction. On the actuator spring 8, each piezoelectric element 16 has a piezoelectric element bonding position 2 indicated by a hatched area in FIG.
1 and 21 (corresponding to the first and second support portions in the claims) are respectively adhered and fixed. here,
The drive gap 25 is formed between the piezoelectric element bonding positions 21 where the piezoelectric element 16 is bonded and fixed.

The actuator spring 8 is made of SUS304
As shown in FIG. 4A, a short I-shaped spring of the center spring 18 forming the actuator spring 8 is formed such that the spring length (Lc) and the spring width (Wc) are substantially equal. And the elongated I-shaped spring of the two side springs 17 has a spring width (Ws1, Ws1).
It is desirable that the spring length (Ls1, Ls2) is set to be sufficiently longer than s2). At this time, the smaller the spring width of the center spring 18 and the side spring 17, the lower the rotational stiffness can be designed, so that the drive loss of the piezoelectric element can be suppressed small. The main resonance cannot be set high. The thickness (ta) of the actuator spring 8 is determined in consideration of the impact resistance (load / unload durability) of the stress applied to the piezoelectric element due to the impact resistance and the warpage caused by the load / unload of the magnetic head support mechanism 5. It is desirable to set the thickness as thick as possible within the range allowed by the mounting. However, if the thickness is too large, the spring widths (Wc, Ws1, Ws) of the center spring 18 and the side spring 17 are set.
2) cannot be processed thinly. For example, when the plate thickness of the actuator spring 8 is set to ta = 200 μm, when the etching process is used, both the center spring 18 and the side spring 17 can be processed only up to the plate thickness of about 200 μm. When processing by wire cutting or the like, the restriction is not applied, but care must be taken because productivity is reduced and costs are increased.

As shown in FIG. 4A, the distance between the end of the center spring 18 on the magnetic head 1 side and the side edge of the side spring 17 on the piezoelectric element 16 side is LD. Then, if the distance LD is reduced to bring the center spring 18 and the side spring 17 closer to each other, the rotational rigidity is reduced and the head drive magnification (the drive amount of the magnetic head with respect to the displacement of the piezoelectric element) is increased. Resonance decreases. Conversely, if the distance LD is increased and the center spring 18 and the side spring 17 are separated, the drive shaft shifts from above the center spring toward the magnetic head, thereby reducing the head drive magnification. However, the actuator main resonance can be designed to be high. That is, by bringing the end of the center spring 18 on the side of the magnetic head 1 and the side edge of the side spring 17 on the side of the piezoelectric element 16 close to each other, the drive magnification of the magnetic head can be set to be large. The main resonance of the actuator can be set high by separating the side edge from the side of the piezoelectric element 16.

On the other hand, as a piezoelectric element used for minute driving of the magnetic head, a vertical effect element, a horizontal effect element, a stacked vertical effect element, or the like can be used. Considering the workability of the electrical connection, the horizontal effect element is easy to use, but if the cost is less restrictive, use a stacked piezoelectric actuator (stacked vertical effect element) that can be used at low voltage. May be. When the lateral effect element is used, the piezoelectric constant d in a state where no stress is applied is obtained by the following equation (1).

[0021]

(Equation 1)

Here, k: electromechanical coupling coefficient, εT: dielectric constant, YE: Young's modulus (N / m 2)

Using this piezoelectric constant d, the generated force is calculated from the electric field and the cross section of the element. At this time, the displacement (strain) of the piezoelectric element is equal to the free length excluding the fixed part (hereinafter referred to as the drive length). If the drive voltage cannot be set high due to circuit limitations because of the proportionality, it is preferable to set the drive length of the piezoelectric element large in order to ensure a sufficiently wide magnetic head movable range. For example, in the case of a transverse effect element using a soft material of a lead titanate or zirconium titanate ceramic material,
The drive displacement (strain) of the piezoelectric element is about 0.05% of the drive length, and when a voltage of 30 V is applied to the piezoelectric element with a drive length of 2 mm,
The displacement (strain) of the piezoelectric element is about 0.16 μm, but when a piezoelectric element having a drive length of 4 mm is used, a displacement of 0.32 μm can be obtained.

The driving length of the piezoelectric element is determined by
A drive gap 25 (Lp: see FIG. 4B) provided at the center of the actuator spring 8. In order to secure a wide drive range of the magnetic head, the drive gap 25 is set within a range where the rigidity of the actuator spring is not reduced. Drive gap 25
Should be set longer. As shown in FIGS. 2 (a), 2 (b) and 2 (c), a pair of such piezoelectric elements 16 is formed, and the longitudinal direction of the piezoelectric element 16 is sandwiched with respect to the central axis of the actuator spring 8 in the longitudinal direction. The (strain direction) is arranged in a direction parallel to the longitudinal center axis of the actuator spring 8. At this time, the connection positions of the respective piezoelectric elements 16 to the actuator spring 8 are located at two positions on the holder arm caulking position side and the suspension caulking position side across the drive gap 25 as shown by the hatched portion in FIG. Prepare each one. Of these, the connection position on the holder arm caulking position side (piezoelectric element bonding position 21) may be any position that does not interfere with the holder arm 11, but the connection position on the suspension caulking position side (piezoelectric element bonding position 21) is the side spring 17 It is desirable to set so as to be located between the center spring 18 and the center spring 18.

An adhesive is used to connect the piezoelectric element 16 and the actuator spring 8. Depending on the wiring method of the piezoelectric element (whether or not the ground is taken to the actuator spring), a conductive adhesive may be used or an insulating adhesive may be used. It depends on whether a natural adhesive is used. In addition, as for the bonding area of the piezoelectric element, when the bonding is performed on the actuator spring as in the first embodiment, the driving force of the piezoelectric element is transmitted to the actuator spring via the adhesive. Therefore, it is desirable that the bonding area be as large as possible. However, if the length of the bonding portion is too long, a sufficient driving length cannot be secured in a limited actuator spring. The length of the bonded portion before and after is appropriately about 20 to 40% of the length of the piezoelectric element.

As described above, the actuator spring 8
The pair of piezoelectric elements 16 connected to D and D in FIG.
The magnetic head support mechanism 5 is minutely moved in the seek direction by alternately driving the center spring 18 of C and rotating the center spring 18 of C, and bending the side springs 17 of A and B in the direction perpendicular to the longitudinal axis of the side springs. It is driven (see FIG. 4A). At this time, the piezoelectric element 16 mounted on the upper part of the actuator spring 8 transmits the driving force to the actuator spring 8 via the adhesive at the piezoelectric element bonding position 21 and the three springs (the center spring 18 and the side spring 17). )
Is displaced (see FIG. 4B).

When a magnetic head is driven by using two piezoelectric elements, two types of driving methods are conceivable. One is a two-sided driving method as shown in FIG. 5A, and the other is a one-sided driving method shown in FIG.
In the case of the double-sided drive method, the same voltage (initial voltage: 15 V in the figure) is applied to both the piezoelectric elements A and B in the neutral state as shown in FIG. As shown in (ii) and (iii) of FIG. 5A, 0 V is applied to one piezoelectric element, and a voltage twice as high as that in neutral (30 V in the figure) is applied to the other piezoelectric element. As a result, it is possible to perform a differential operation in which the piezoelectric element on one side (0 V) is extended and the piezoelectric element on the other side (30 V) is reduced, so that the head drive magnification can be increased. In the case of the one-side drive system, no voltage is applied to the piezoelectric elements 16A and 16B in the neutral state as shown in (i) of FIG.
At the time of driving the head, as shown in (ii) and (iii) in FIG. 5B, a voltage is applied only to the piezoelectric element on the driving side (30 V in the figure), and no voltage is applied to the opposite piezoelectric element. Leave. In this case, only one (drive-side) piezoelectric element is displaced, and the other remains fixed. In the case of such a driving method, the head driving magnification is reduced to about 前 記 compared to the double-sided driving method. However, since there is no need to apply a voltage in a neutral state, an actuator spring using a piezoelectric element in an initial state is used. Impact (initial stress, etc.) and is excellent in workability (productivity) and power saving.

FIG. 6 shows the results of a simulation analysis of the behavior of the actuator spring when the driving force of the piezoelectric element acts on the fine actuator of the first embodiment. SUS304 with a thickness of 200 μm is used for the actuator spring and PZT for the piezoelectric element.
(L × W × t = 2.5mm × 1.0mm × 0.2mm) and 30V
A driving force (80 gf) equivalent to the applied voltage is applied. It can be seen that the displacement of the piezoelectric element causes the side spring to bend around the center spring and drives the magnetic head support mechanism.

FIG. 7A shows the relationship between the driving distance of the magnetic head and the driving displacement of the piezoelectric element when the actuator spring of the first embodiment is used, and the horizontal axis represents the driving displacement of the piezoelectric element. The vertical axis indicates the magnetic head drive distance (μm). FIG. 6B shows the frequency characteristics of the fine actuator section of the present embodiment, where the horizontal axis represents frequency (Hz) and the vertical axis represents gain (d).
B) is shown. All are analysis results by simulation. Compared with the conventional two-stage actuator introduced in FIG. 24 (the type in which the actuator spring is bent by two piezoelectric elements to drive the HGA as in the present embodiment), the two-stage actuator of the present embodiment is a magnetic head. It can be seen that the drive magnification (both evaluated by the double-sided drive method) is large, and at the same time, the actuator main resonance (Sway) can be designed to be high. That is, it is possible to obtain good vibration characteristics in which no resonance peak appears even in a high frequency band.

The conventional two-stage actuator shown in FIG. 24 uses a pair of piezoelectric elements to flex the actuator spring to drive the HGA.
The two-stage actuator of the present invention is common to the two-stage actuator of the present invention, but differs from the two-stage actuator of the present invention in that the piezoelectric element is arranged at right angles to the longitudinal center axis of the actuator spring. In the case of this conventional two-stage actuator, two
Since the piezoelectric elements are arranged vertically, the driving length of the piezoelectric element cannot be larger than the entire width of the actuator spring. Therefore, there is a disadvantage that it is difficult to increase the displacement amount of the piezoelectric element, and the drive range of the magnetic head cannot be widened. On the other hand, in the two-stage actuator of the present invention, a pair of piezoelectric elements are arranged in parallel along the longitudinal direction of the actuator spring. (The length can be increased), so that it is easy to increase the amount of displacement of the piezoelectric element and extend the drive range of the magnetic head.

The actuator spring portion of the conventional two-stage actuator has a pair of side springs arranged in series at right and left ends at right angles to the longitudinal axis of the actuator spring, similarly to the actuator spring of the present invention. Although the center spring is common on the center axis in the longitudinal direction (see FIG. 24), in the two-stage actuator of the present invention, the center spring is extremely shorter (width and length) than the side spring. The difference is that an I-shaped leaf spring is used, and the point of application of the driving force by the piezoelectric element is set closer to the holder arm than the center spring. The two-stage actuator of the present invention
Thus, the rotation axis can be set on the center spring, and the drive magnification of the magnetic head can be increased. Further, the actuator spring structure in which a short I-shaped leaf spring is arranged on the drive shaft can set the out-of-plane rigidity high while keeping the in-plane rotational rigidity small compared to the conventional two-stage actuator, so Out-of-plane motion (e.g., escape in the roll / pitch direction or warpage in the perpendicular direction to the medium) can be reduced to minimize the loss of driving force, and ensure impact resistance and load / unload durability. Has become possible.

Next, a second embodiment will be described with reference to the drawings. FIG. 8A is a plan view of an actuator spring according to the second embodiment. In the first embodiment, the center spring provided on the actuator spring 8 is replaced with the actuator spring 8
And a single short I-shaped leaf spring arranged on the central axis in the longitudinal direction of. On the other hand, in the second embodiment, the center spring 18 extends in the direction parallel to the two side springs 17, that is, in the direction orthogonal to the longitudinal center axis of the actuator spring. It is arranged so that it exists. At this time, the pair of center springs 18 are disposed closer to the holder arm than the side springs 17 (corresponding to a portion closer to the second support portion in the claims), and the length of the actuator spring is longer than the side springs. It is arranged near the central axis in the direction. At this time, the pair of piezoelectric elements 16 are arranged in parallel with respect to the center axis in the longitudinal direction of the actuator spring, and one end of the piezoelectric element bonding position 21 is located between the center spring 18 and the side spring 17. In the second embodiment, since the driving displacement of the piezoelectric element is received by the bending of two side springs, which are long I-shaped leaf springs, and two center springs, which are two short I-shaped leaf springs, HGA support stiffness is significantly increased. Therefore, it is effective when it is desired to suppress actuator resonance up to a high frequency band, or when it is desired to reduce the thickness of the actuator spring while maintaining good frequency characteristics without lowering the out-of-plane rigidity.

Next, a third embodiment will be described with reference to the drawings. FIG. 8B is a plan view of an actuator spring according to the third embodiment. In the first embodiment, the side springs provided on the actuator spring are arranged in series in a direction perpendicular to the central axis in the longitudinal direction of the actuator spring. However, in the third embodiment, the side spring 17 is connected to the HGA side. The pair of piezoelectric elements 16 which are arranged in the shape of a letter "C" that opens toward the holder and that are arranged in parallel with the central axis in the longitudinal direction of the actuator spring being opened toward the holder arm. It is arranged in the shape of a letter. That is, the center spring 18 extends in the direction of the central axis on the central axis, and the two side springs 17 are located at a position sandwiching the central axis at a distance greater than the distance between the second support portions. The first support portion extends in a direction intersecting with the central axis so that the interval on the first support portion side is large. The two piezoelectric elements 16 are arranged such that the distance between the center axis and the actuator spring is greater than the distance between the first support portions and the distance between the second support portions. The driving direction of the element 16 is provided so as to intersect the central axis. Further, the side spring 17 and the piezoelectric element 16 located on the same side with respect to the central axis are arranged such that the extending direction of the side spring 17 and the driving direction of the piezoelectric element 16 intersect at right angles. It is configured.

By arranging the piezoelectric element in such a manner that its driving direction is oblique to the central axis in the longitudinal direction of the actuator spring, the driving length can be made longer, so that the driving of the magnetic head is performed. The range can be expanded. Further, by configuring the extending direction of the side spring 17 and the driving direction of the piezoelectric element 16 to intersect at right angles, the driving force of the piezoelectric element 16 is perpendicular to the bending direction of the leaf spring of the side spring 17. By acting on it, drive loss can be suppressed and the actuator spring can be designed compact.

Next, a fourth embodiment will be described with reference to the drawings. FIGS. 9A, 9B and 9C are perspective views showing a two-stage actuator according to the fourth embodiment. FIGS. 10A and 10B are a perspective view and a side view showing details of a piezoelectric element connecting portion in the fourth embodiment. FIGS. 11A and 11B are a plan view, a side view, and a configuration diagram illustrating the structure of a two-stage actuator according to the fourth embodiment. FIG.
(A) And (b) is a side view explaining the example of connection of the piezoelectric element to the fine actuator part of the two-stage actuator in the fourth embodiment.

As shown in FIGS. 9 to 11, in the fourth embodiment, the actuator spring 8 of the fine actuator 6 is replaced with an upper actuator spring 19 (corresponding to the first spring in the claims), The lower actuator spring 20 (corresponding to a second spring portion in the claims) is formed separately, that is, divided into two upper and lower thin steel plates. Among the actuator springs 8 formed by dividing the upper and lower two thin steel plates, the lower actuator spring 20 includes only one center spring 18 having a short I-shaped leaf spring shape and a longitudinal length of the actuator spring. It is arranged on the central axis of the direction. On the other hand, among the actuator springs 8, only a pair of long I-shaped leaf spring side springs 17 are arranged in series in the upper actuator spring portion 19 in a direction orthogonal to the central axis in the longitudinal direction of the actuator spring. are doing. Then, the upper actuator spring 19 and the lower actuator spring 20 are bonded and joined to form one actuator spring 8.
Is formed, the center spring 18 is formed in the lower stage and the side spring 17 is formed in the upper stage.

In the fourth embodiment, the upper actuator spring 19 is provided with the side spring 17 and
Although the center spring 18 is set in the lower actuator spring 20, the location where the side spring 17 and the center spring 18 are provided may be reversed. An adhesive may be used for joining the upper and lower actuator springs, but laser spot welding used for joining the magnetic head support mechanism may be used. At this time, FIG.
As shown in (a), the plate thickness (t1) of the upper actuator spring 19 and the plate thickness (t
2) is set to be equal, and the thickness (t1 + t2) when one actuator spring is formed by laminating the upper and lower two actuator springs is the thickness (ta) of the first two-stage actuator. ).

As shown in FIG. 10B, the driving clearance (LpL) of the lower actuator spring 20
(Corresponding to the second driving gap in the claims) is shorter than the driving gap (LpU) of the upper actuator spring (corresponding to the first driving gap in the claims) by the bonding length of the piezoelectric element. And the length of the driving gap (LpU) of the upper actuator spring is set to be equal to the length of the piezoelectric element in the driving direction.
For this reason, the pair of driving piezoelectric elements 16 ride on the lower actuator spring so as to straddle the driving gap (LpL), and at the same time, are connected so as to be sandwiched between the driving gaps (LpU) of the upper actuator spring. (Fig. 10
(B)). In other words, a step is formed at each of the first and second support portions by setting one of the first and second drive gaps wider than the other. The fixing of the piezoelectric element 16 to the actuator spring is performed with one end and the other end of the piezoelectric element 16 in the driving direction fitted into the step.

As a result, for example, as shown in FIG. 12 (a), the bonding area of the piezoelectric element 16 can be secured on both the lower surface and the vertical end surface of the element, so that the bonding of the piezoelectric element becomes strong and the adhesive slips. Drive loss can be suppressed, and the thickness of the upper actuator spring (t
Only 1) the mounting height can be kept low. Alternatively, the thickness of the piezoelectric element (t
By increasing (PZT), it is possible to increase the generated force (in proportion to the cross-sectional area of the element) and to increase the rigidity of the fine actuator drive unit, thereby providing a two-stage actuator excellent in impact resistance and reliability. Can be provided.

In the example shown in FIG. 12A, the upper actuator spring and the lower actuator spring have the same plate thickness. In the example shown in FIG. 12B, the upper actuator spring and the lower actuator spring have the same thickness. The thickness of the spring is different, and the thickness (t2) of the lower actuator spring is
It is set to be smaller than the plate thickness (t1) of the spring. Also in this case, the plate thickness (ta) of the actuator spring 8 when the upper and lower actuator springs are bonded to each other is set to be the same as in the first to third embodiments.

Thus, the upper and lower actuator springs 1 of the piezoelectric element 16 in the step formed by making the driving gaps of the upper and lower actuator springs 19 and 20 different from each other as described above.
The joining area (particularly, the vertical end face) at the points 9 and 20 is further increased, so that the loss of driving force can be suppressed and the piezoelectric element itself can be designed to be thicker, so that a sufficiently strong generating force can be obtained. In addition, when the thickness of the piezoelectric element is not changed, the mounting height can be set small, so that mounting between narrow plates is possible. In this case, since the plate thickness (t2) of the lower actuator spring is set to be smaller than the plate thickness (t1) of the upper actuator spring, the rigidity of the lower actuator spring is as shown in FIG. ), The rigidity needs to be adjusted by setting the spring width (Wc) wider, for example, because the thickness is reduced due to the decrease in the plate thickness.

Next, a fifth embodiment will be described with reference to the drawings. (A), (b) and (c) of FIG.
FIG. 21 is a perspective view and a configuration diagram showing a structure of a two-stage actuator according to a fifth embodiment. FIG.
(A), (b) and (c) show the second embodiment of the fifth embodiment.
FIG. 3 is a plan view, a side view, and an explanatory diagram illustrating assembly of the stage actuator. FIGS. 15A, 15B, and 15C are side views illustrating the connection of the piezoelectric element in the two-stage actuator according to the fifth embodiment.

As shown in FIG. 13, the magnetic head supporting mechanism 5 includes a load beam section 4. The load beam part 4 is formed of one sheet of steel,
A, a connecting portion 4B, and a reinforcing plate 23. The load beam part 4 is provided with the center spring part 1 of the actuator spring 8 set in the first embodiment.
It is set so as to overlap (overlap) with the part excluding the part 8 and the side spring part 17. Here, the main body 4A is joined to the first support of the actuator spring 8, the reinforcing plate 23 is joined to the second support of the actuator spring 8, and the connecting part 4B is connected to the main body 4A and the reinforcing plate. 23 are connected. In the example of FIG. 13, the connecting portion 4B extends in a direction perpendicular to the central axis of the actuator spring 8 at two places with the central axis of the actuator spring 8 interposed therebetween.
And the other end is connected to the reinforcing plate 23. At this time, a drive gap (LpS: see FIG. 14B) of the piezoelectric element 16 formed by the load beam 4 (corresponding to a load beam side drive gap in the claims) is formed in the actuator spring 8. Drive gap (L
p: see FIG. 14 (b)).

Thus, when the magnetic head supporting mechanism 5 is joined to the actuator spring 8 by laser spot welding or the like, the driving gap 8 is placed in a state where the actuator spring 8 is on the upper stage and the load beam unit 4 is on the lower stage. The main part 4A of the load beam 4 and a part of the reinforcing plate 23 project from the driving gap 25 (Lp) to form the piezoelectric element bonding position 21. At this time, when the piezoelectric element bonding position 21 is viewed from the side, an L-shaped connection portion is formed by the actuator spring 8 and the steel plate of the load beam 4 (and the reinforcing plate 23) (FIG. 14).
(B)). The driving piezoelectric element 16 is embedded in the L-shaped piezoelectric element bonding position 21, and the bottom surface and the vertical end surface of the element are fixed with an adhesive or the like, whereby the actuator spring 8 (and the load beam 4 joined to the actuator spring 8). And the piezoelectric element 16 are joined. In other words,
The drive gap Lp is provided between the main body 4A and the reinforcing plate 23 at a position corresponding to the drive gap of the actuator spring.
By forming the load beam side driving gap Lps narrower than that, an L-shaped connection portion (step portion) is formed at each of the first and second support portions. The piezoelectric element 16 is fixed to the actuator spring by one end and the other end of the piezoelectric element 16 in the drive direction.
It is performed in a state where it is fitted in the letter-shaped connection part.

The load beam 4 and the reinforcing plate 23 are formed of a single steel plate at first, and the magnetic head supporting mechanism 5 is joined to the actuator spring 8 (assembly).
(At this time, the portion of the reinforcing plate 23 is also
(Joint with the actuator spring 8 in the same way as above.)
Connecting part 4B connecting load beam part 4 and reinforcing plate 23
The processing is easy if the part is cut off (FIG. 14).
(C)).

Thus, also in the fifth embodiment, as in the case of the fourth embodiment, the bonding portion of the piezoelectric element 16 can be secured on both the lower surface and the vertical end surface of the element, so that the bonding is firm. The drive loss due to the slip of the adhesive can be suppressed, and the actuator spring 8
The mounting height (see FIG. 15A) can be reduced by the plate thickness (ta). Alternatively, conversely, by increasing the thickness (tPZT) of the piezoelectric element 16 while keeping the mounting height as it is, it is possible to increase the generated force of the drive unit (see FIG. 15B). Further, as shown in FIG. 15C, it is possible to provide a two-stage actuator excellent in impact resistance and reliability because the thickness of the actuator spring can be increased and the rigidity of the fine actuator drive unit can be increased. Can be. Alternatively, when the thickness of the piezoelectric element is not changed, the mounting height can be set small, so that mounting between narrow plates becomes easy.

Next, a sixth embodiment will be described with reference to the drawings. FIGS. 16 (a), (b) and (c)
It is the perspective view and composition figure showing the structure of the two-stage actuator in a 6th embodiment. FIG. 17 (a),
(B) is a top view and a lineblock diagram showing a two stage actuator of a 6th embodiment. FIGS. 18 (i), (i)
(i) and (iii) are a plan view and a side view illustrating the operation principle of the two-stage actuator of the sixth embodiment.

In FIG. 16, similarly to the fourth embodiment, similarly, the actuator spring 8 is formed of two upper and lower thin steel plates, and the upper actuator spring 19 has a pair of long I-shapes. Are arranged in series in a direction perpendicular to the central axis in the longitudinal direction of the actuator spring. On the other hand, in the lower actuator spring 20, only one short I-shaped center spring 18 is arranged on the central axis in the longitudinal direction of the actuator spring. These upper actuator spring 19 and lower actuator spring 19
The spring 20 is attached and one actuator
A spring 8 is formed. At this time, the center stage 18 is formed in the lower stage, and the side spring 17 is formed in the upper stage.

The upper actuator spring 1
9 is provided with a drive gap 25 as in the fourth embodiment, but no drive gap is set in the lower actuator spring 20. The lower actuator
A pair of sliding modes (1 ··) is provided at a position (corresponding to the position of the second support portion in the claims) closer to the holder arm than the center spring 18 with respect to the longitudinal center axis of the spring 20.
The lower surface (corresponding to the end surface in the claims) of the piezoelectric element 16 driven in (5 modes) is bonded. On the other hand, from the suspension caulking position 9 of the load beam part 4 constituting the magnetic head support mechanism 5 to the rear end, two piezoelectric elements extending toward the holder arm with the longitudinal center axis of the actuator spring interposed therebetween. A space 26 (corresponding to a fixing portion in the claims) is provided. The piezoelectric element bonding space 26 is provided for the lower actuator spring 2.
It is configured so as to face the point 0 at a distance in the thickness direction of the actuator spring. The upper surface of the piezoelectric element 16 (corresponding to the end face in the claims) is bonded to the piezoelectric element bonding space 26 while the piezoelectric element 16 is sandwiched between the piezoelectric element bonding space 26 and the lower actuator spring 20. Is done.

As shown in FIG. 18, the piezoelectric element 16 driven in the sliding mode (1.5 mode) is driven so that the upper surface slides back and forth when the lower surface is fixed and a voltage is applied. 2) Since the projection surface shape is close to a square with a short length and a wide width, it is desirable to secure a sufficient bonding area in the piezoelectric element bonding space 26. Also,
The thickness (tPZT) of the piezoelectric element 16 and the plate thickness (t1) of the upper actuator spring 19 are set to be equal, and the piezoelectric element bonding space 20 of the load beam 4 and the upper surface of the piezoelectric element 16 Note that are within the same plane. Thus, the sliding mode (1.5)
When a two-stage actuator is constructed using a pair of piezoelectric elements driven in the mode (mode), a constant voltage (initial voltage: in FIG. 18 (i)) is applied to both the piezoelectric element A and the piezoelectric element B at the neutral position. 15V)
When the magnetic head is driven, one of the piezoelectric elements is set to 0 V, and the other is set to a voltage twice as high as that in neutral (FIGS. 18 (ii), (ii)
A voltage of 30 V is applied during i) to drive both piezoelectric elements differentially. In such a two-stage actuator, a large bonding area for the piezoelectric element can be ensured, and at the same time, the piezoelectric element is sandwiched between the upper and lower parts and joined, so that the rigidity of the fine actuator driving unit can be designed to be strong.

In a conventional two-stage actuator using the sliding mode (1.5 mode) of the piezoelectric element, FIG.
There is a type driven by using a hinge as shown in FIG.
In this case, a pair of piezoelectric elements are arranged in parallel on the left and right sides of the plate that joins the holder arm tip with the center axis in the longitudinal direction of the holder arm therebetween. To a mounting block having a hinge.

At this time, a magnetic head support mechanism is connected to the mount block. When driving the magnetic head, a pair of left and right piezoelectric elements are alternately arranged in the longitudinal direction of the HGA as shown in FIG. (Sliding), whereby the two hinge portions of the mount block are alternately shifted left and right (in the front-rear direction), and the magnetic head support mechanism is driven to rotate minutely in the seek direction. 2 thin like this
When an HGA is driven by a hinge, the hinge portion must be made as thin as possible in order to increase the drive magnification, and must be disposed as close as possible to the central axis in the longitudinal direction. for that reason,
HG due to insufficient out-of-plane rigidity of fine actuator drive
A can not apply a large pressing load to A
It was difficult to secure impact resistance and load / unload durability.

On the other hand, in the two-stage actuator according to the sixth embodiment, one short I-shaped center spring (rotary drive) is arranged on the actuator center axis, and a pair of long I-shaped center springs are provided at the left and right ends of the actuator. Since the side springs (flexible drive) are arranged, the out-of-plane rigidity can be set high while keeping the in-plane rotational rigidity small. Therefore, it can cope with the high load design of the magnetic head support mechanism,
It is easy to ensure impact resistance and load / unload durability.

Next, a seventh embodiment will be described with reference to the drawings. FIG. 17C is a plan view showing a two-stage actuator according to the seventh embodiment. Seventh
In the two-stage actuator of this embodiment, the piezoelectric element bonding space 27 provided at the rear end of the suspension caulking position of the load beam 4 in the sixth embodiment is used.
To the sub-spacer 24, which is a separate component from the load beam unit 4.
It is provided at the rear end (corresponding to the fixing member in the claims). Therefore, as a procedure for assembling, first, the magnetic head support mechanism 5 (load beam 4) is joined to the actuator spring 8 to which the lower surface of the piezoelectric element 16 is connected, and then the sub-spacer 24 is attached to the load beam 4. Connect to suspension caulking position 9. here,
The sub-spacer 24 is joined to a portion of the main body 4 </ b> A of the load beam 4 opposite to the upper actuator spring 19. At this time, the sub-spacer 24
Of the piezoelectric element bonding space 27 of the piezoelectric element 16
To the upper surface. When spot welding is used to join the magnetic head support mechanism 5 and the actuator spring 8 as in the sixth embodiment, the upper surface of the piezoelectric element 16, the upper actuator spring 19, and the load beam 4 are the same. In order to be on the surface, the bonding between the upper surface of the piezoelectric element 16 and the piezoelectric element bonding space 27 by the adhesive and the spot welding between the upper actuator spring 8 and the load beam 4 must be performed simultaneously, resulting in poor workability.
On the other hand, in the seventh embodiment, the sub-spacer 24 having the piezoelectric element bonding space 27 is prepared, and the assembly of the magnetic head support mechanism 5 to the actuator spring 8 and the joining of the piezoelectric element 16 are performed in separate steps. As a result, workability is improved and assembling accuracy can be improved.

[0055]

According to the magnetic head positioning mechanism of the present invention, a driving force is generated in the two piezoelectric elements by alternately applying a voltage to the two piezoelectric elements, and the actuator spring is driven by the driving force. The magnetic head support mechanism connected to the fine actuator section is finely driven in the seek direction by elastically bending the section, and the individual magnetic heads are individually positioned and controlled, so that a high-precision track following operation (follow-up operation) is performed. Ing)
It can be performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention,
(A) is a plan view, (b) is a side view, (c1) is a side view of a main part, and (c2) is a plan view of a main part.

FIGS. 2A and 2B are diagrams showing details of a fine actuator unit according to the first embodiment, wherein FIG. 2A is a plan view, FIG. 2B is a side view, and FIG. 2C is a plan view of an actuator spring.

FIG. 3 is a perspective view illustrating a configuration of a two-stage actuator according to the first embodiment of the present invention.

4A and 4B are diagrams illustrating a structure and an operation principle of an actuator spring portion according to the first embodiment of the present invention, wherein FIG. 4A is a plan view and FIG. 4B is a side view.

FIG. 5 is a plan view illustrating a method for driving the two-stage actuator according to the first embodiment of the present invention.

FIGS. 6A and 6B are diagrams showing a spring behavior during a fine actuator operation according to the first embodiment of the present invention, wherein FIGS. 6A and 6B are displacement diagrams showing the spring behavior; FIGS.
(C) is an enlarged view of a main part.

FIG. 7 is a graph showing the relationship between the displacement of the piezoelectric element of the two-stage actuator and the driving distance of the magnetic head in the first embodiment of the present invention, and a characteristic diagram showing frequency characteristics.

FIG. 8 shows a second embodiment according to the second and third embodiments of the present invention.
It is a figure which shows a stage actuator, (a) is 2nd.
FIG. 14B is a plan view of a two-stage actuator according to the third embodiment, and FIG. 14B is a plan view of the two-stage actuator according to the third embodiment.

FIG. 9 is a perspective view showing a two-stage actuator according to a fourth embodiment of the present invention.

10A and 10B are diagrams illustrating details of a piezoelectric element connecting portion of a two-stage actuator according to a fourth embodiment of the present invention, where FIG. 10A is a perspective view and FIG. 10B is a side view.

FIGS. 11A and 11B are diagrams illustrating a structure of a two-stage actuator according to a fourth embodiment of the present invention, wherein FIG.
Is a plan view and a side view, and (b) is a configuration diagram.

FIG. 12 is a diagram illustrating a piezoelectric element connection portion of a two-stage actuator according to a fourth embodiment of the present invention;
(A) is a side view which shows an example of a piezoelectric element connection part, (b) is a side view which shows another example.

13A and 13B are diagrams illustrating a configuration of a two-stage actuator according to a fifth embodiment, wherein FIG. 13A is a perspective view illustrating an assembled state, FIG. 13B is a perspective view illustrating a relationship with a piezoelectric element, and FIG. FIG. 3 is a perspective view showing a relationship between an actuator spring and a load beam unit.

14A and 14B are diagrams illustrating a configuration of a two-stage actuator according to a fifth embodiment, wherein FIG. 14A is a plan view and a side view, FIG. 14B is an enlarged side view, and FIG. FIG.

FIGS. 15A and 15B are diagrams illustrating the relationship between the thickness of a piezoelectric element and the mounting height of a two-stage actuator according to a fifth embodiment. FIG.
Side view when the thickness of the spring is the same, (b) is a side view when the thickness of the piezoelectric element is larger than the thickness of the actuator spring, and (c) is when the thickness of the actuator spring and the piezoelectric element are thick and the same. It is a side view.

16A and 16B are diagrams illustrating a configuration of a two-stage actuator according to a sixth embodiment, wherein FIG. 16A is a perspective view illustrating an assembled state, FIG. 16B is a perspective view illustrating a relationship with a piezoelectric element, and FIG. FIG. 3 is a perspective view showing a relationship between an actuator spring and a load beam unit.

FIGS. 17A and 17B are diagrams showing a configuration of a two-stage actuator according to the sixth and seventh embodiments, wherein FIG.
FIG. 14B is a plan view showing a two-stage actuator of the sixth embodiment, FIG. 14B is a configuration diagram showing the two-stage actuator of the sixth embodiment, and FIG. 14C is a side view showing the two-stage actuator of the seventh embodiment. FIG.

FIG. 18 is an explanatory diagram illustrating a method of driving a two-stage actuator according to a sixth embodiment.

FIG. 19 is a plan view, a side view, and an operation view showing a conventional example of a magnetic head positioning mechanism, and a perspective view and a plan view showing a configuration of a magnetic head support mechanism.

FIG. 20 is a perspective view showing a conventional example (a head element driving method) of a two-stage actuator.

FIG. 21 is a perspective view and a plan view showing a conventional example (slider driving method) of a two-stage actuator.

FIG. 22 shows a conventional example of a two-stage actuator (force-
FIGS. 4A and 4B are a perspective view and a plan view illustrating an acceleration-type HGA driving method). FIGS.

FIG. 23 shows a conventional two-stage actuator (force-
It is a top view which shows the displacement type HGA drive system 1).

FIG. 24 shows a conventional example of a two-stage actuator (force-
It is explanatory drawing which shows the displacement type HGA drive system 2).

FIG. 25 shows a conventional two-stage actuator (force-
It is a perspective view which shows the displacement type HGA drive system 3).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic head, 2 ... Slider, 3 ... Gimbal spring, 4 ... Load beam part, 4A ... Body part, 4
B: communication section, 5: magnetic head support mechanism (suspension), 6: fine actuator section, 7: course actuator section, 8: actuator spring, 9: suspension caulking position, 10: holder arm Caulking position, 11 Holder arm, 12 Moving coil, 13 Arm block (carriage), 1
6 ... piezoelectric element, 17 ... side spring, 18 ...
Center spring, 19 Upper actuator spring, 20 Lower actuator spring, 2
1 ... piezoelectric element bonding position, 23 ... reinforcing plate, 24 ... sub-spacer, 25 ... drive gap, 26 ... piezoelectric element bonding space.

Claims (21)

(57) [Claims] 1. A magnetic head supporting mechanism comprising a magnetic head supporting mechanism and a two-stage actuator, wherein the magnetic head supporting mechanism is configured to support a slider on which a magnetic head is mounted. A fine actuator section for displacing the head in a seek direction by a small amount; and a coarse actuator section for displacing the fine actuator section in a seek direction of the magnetic head by a voice coil motor. It has a thin plate-shaped actuator spring supporting the head support mechanism and two piezoelectric elements, and the minute displacement of the magnetic head support mechanism in the seek direction of the magnetic head is alternately applied to the two piezoelectric elements. By applying a voltage, the two piezoelectric elements To generate a driving force is performed by deflecting the actuator spring portion resiliently by the driving force, the actuator spring, the magnetic head supporting
A first support for supporting a holding mechanism, and the course actuator
A second support portion supported by the first support portion and the first support portion.
And a spring portion connecting between the second support portion.
The spring portion is a sensor comprising one I-shaped leaf spring.
Side spring consisting of a spring and two I-shaped leaf springs
And the center spring has a front side.
On the longitudinal center axis of the actuator spring
The two side springs extending in the center axis direction;
Is a direction orthogonal to the central axis at a position sandwiching the central axis.
A magnetic head positioning mechanism, wherein the magnetic head positioning mechanism extends . Wherein said piezoelectric element is a magnetic head positioning mechanism according to claim 1, characterized in that it is arranged such that the driving direction is a direction parallel with the central axis. 3. A magnetic head support mechanism and a two-stage actuator.
And a magnetic head supporting mechanism , wherein the magnetic head supporting mechanism has a magnetic head mounted thereon.
The two-stage actuator is configured to support a magnetic head support mechanism.
Of the magnetic head in the seek direction of the magnetic head.
In-actuator section and the fine actuator
Of the magnetic head by a voice coil motor.
And a course actuator that displaces
Made, the fine actuator portion, said magnetic head supporting
A thin plate-shaped actuator spring supporting the mechanism
A seek direction of the magnetic head of the magnetic head supporting mechanism , comprising two piezoelectric elements ;
A small amount of displacement is applied to the two piezoelectric elements alternately.
When applied, a driving force is generated in the two piezoelectric elements.
And the actuator spring is driven by the driving force.
The actuator spring is elastically bent so that the actuator spring is supported by the magnetic head support.
A first support for supporting a holding mechanism, and the course actuator
A second support portion supported by the first support portion and the first support portion.
And a spring portion connecting between the second support portion.
The spring portion is a sensor comprising one I-shaped leaf spring.
Side spring consisting of a spring and two I-shaped leaf springs
And the center spring has a front side.
Extending in the direction of the central axis on the central axis;
The second spring is provided at a position sandwiching the center shaft.
The interval on the first support portion side is larger than the interval on the holding portion side.
A magnetic head positioning mechanism extending in a direction intersecting the central axis . 4. The two piezoelectric elements are located on the actuator spring and sandwich the center axis,
The driving direction of the piezoelectric element is provided so as to intersect with the central axis so that an interval on the second support portion side is larger than an interval on the first support portion side. 3. The magnetic head positioning mechanism according to 3 . 5. The side spring and the piezoelectric element located on the same side with respect to the central axis such that an extending direction of the side spring and a driving direction of the piezoelectric element intersect at right angles. The magnetic head positioning mechanism according to claim 4 , wherein the magnetic head positioning mechanism is configured. 6. The I-shaped leaf spring constituting the center spring has a spring length substantially equal to the spring width, and the I-shaped leaf spring constituting the side spring has a length smaller than the spring width. The magnetic head positioning mechanism according to any one of claims 1 to 5 , wherein the spring length is configured to be sufficiently long. 7. A magnetic head support mechanism and a two-stage actuator.
And a magnetic head supporting mechanism , wherein the magnetic head supporting mechanism has a magnetic head mounted thereon.
The two-stage actuator is configured to support a magnetic head support mechanism.
Of the magnetic head in the seek direction of the magnetic head.
In-actuator section and the fine actuator
Of the magnetic head by a voice coil motor.
And a course actuator that displaces
Made, the fine actuator portion, said magnetic head supporting
A thin plate-shaped actuator spring supporting the mechanism
A seek direction of the magnetic head of the magnetic head supporting mechanism , comprising two piezoelectric elements ;
A small amount of displacement is applied to the two piezoelectric elements alternately.
When applied, a driving force is generated in the two piezoelectric elements.
And the actuator spring is driven by the driving force.
The actuator spring is elastically bent so that the actuator spring is supported by the magnetic head support.
A first support for supporting a holding mechanism, and the course actuator
A second support portion supported by the first support portion and the first support portion.
And a spring portion connecting between the second support portion.
The spring portion is a sensor comprising two I-shaped leaf springs.
Side spring consisting of a spring and two I-shaped leaf springs
And the two side springs
Is the actuator
Extend in a direction perpendicular to the longitudinal central axis of the ring,
The two center springs sandwich the central axis, and
Closer to the second support portion than the two side springs,
And the center axis is more than the two side springs.
A magnetic head positioning mechanism, wherein the magnetic head positioning mechanism extends in a direction perpendicular to the central axis at a close location . 8. The magnetic head positioning mechanism according to claim 7, wherein the driving direction of the piezoelectric element is parallel to the central axis. 9. The two piezoelectric elements are disposed on the actuator spring at a position sandwiching a central axis of the actuator spring, one end is fixed to a position of the first support portion, and the other end is the other end. A drive gap for driving the piezoelectric element is formed between the first support portion and the second support portion, the drive gap being fixed to a second support portion. Any one of claims 1 to 8
2. The magnetic head positioning mechanism according to claim 1. 10. The actuator spring,
A first spring portion and a second spring portion which are joined in a state of being overlapped in a thickness direction, and one of the first and second spring portions is provided with the side spring, and the other is provided with the side spring; either that center spring is provided in claim 1 to 8, characterized 1
Item 7. A magnetic head positioning mechanism according to Item 1. 11. The two piezoelectric elements are disposed on the actuator spring at a position sandwiching the central axis of the actuator spring, and one end of the piezoelectric element in the driving direction is located at the position of the first support. The other end of the piezoelectric element in the driving direction is fixed to the location of the second support, and the piezoelectric element is driven between the location of the first support and the location of the second support. 11. The magnetic head positioning mechanism according to claim 10, wherein a driving gap is formed for performing the operation. 12. The drive gap comprises a first drive gap provided in the first spring portion and a second drive gap provided in the second spring portion.
One of the driving gaps is set wider than the other to form a step at each of the first and second support portions, and the fixing of the piezoelectric element to the actuator spring is performed in the driving direction of the piezoelectric element. 12. The magnetic head positioning mechanism according to claim 11, wherein said one end and the other end are fitted in said stepped portion. 13. The magnetic head support mechanism includes a load beam portion having one end holding the magnetic head and the other end joined to the actuator spring in a state of being overlapped in a thickness direction. The beam part includes a main body part joined to the first support part, a reinforcing plate part joined to the second support part, and a connecting part connecting the main body part and the reinforcing plate part. The part is configured to be cut after the main body part and the first support part are joined and the reinforcing plate part and the second support part are joined. Any one of 1 to 8 , 10
Item 7. A magnetic head positioning mechanism according to Item 1. 14. The contact portion, the one end connected to the main body, according to claim 13, wherein the other end to the reinforcing plate portion and a support member connected I type Magnetic head positioning mechanism. 15. The two piezoelectric elements are disposed on the actuator spring at a position sandwiching the central axis of the actuator spring, and one end of the piezoelectric element in the driving direction is located at the position of the first support. The other end of the piezoelectric element in the driving direction is fixed to the location of the second support, and the piezoelectric element is driven between the location of the first support and the location of the second support. 15. The magnetic head positioning mechanism according to claim 13, wherein a driving gap is formed for performing the operation. 16. A load beam side drive gap narrower than the drive gap is formed between the main body portion and the reinforcing plate portion at a location corresponding to the drive gap of the actuator spring. A step is formed at each of the second support portions, and the piezoelectric element is fixed to the actuator spring in a state where one end and the other end of the piezoelectric element in the driving direction are fitted into the step. 16. The magnetic head positioning mechanism according to claim 15, wherein: 17. The actuator according to claim 17, wherein the magnetic head support mechanism includes a load beam part having one end holding the magnetic head and the other end joined to the actuator spring in a state of being overlapped in a thickness direction. The spring comprises a thin plate-shaped first spring portion and a second spring portion joined in a state of being overlapped in the thickness direction, wherein the first spring portion is provided with the side spring, and the second spring portion is provided with the side spring. the magnetic head positioning mechanism of any one claim 1 to 8, characterized in that said center spring is provided. 18. The actuator body according to claim 18, wherein the load beam portion includes a main body portion joined to the first support portion on the first spring portion side, a portion of the second support portion on the second spring side, and a portion of the actuator spring. And two fixing portions facing each other with a predetermined interval in the thickness direction, wherein the two fixing portions are
The piezoelectric element is disposed at a position sandwiching a longitudinal center axis of the actuator spring, and the piezoelectric element is configured to be driven to slide in a direction orthogonal to a thickness direction of the actuator spring, and the piezoelectric elements slide with each other. The two driving end faces are the second end faces facing the fixed portion.
18. The magnetic head positioning according to claim 17 , wherein the magnetic head positioning is fixed to the second support portion and the fixed portion while being sandwiched between the support portion and the fixed portion. mechanism. 19. The load beam part includes a main body part joined to the first support part on the first spring part side, and is fixed to a position of the main body part opposite to the first spring part side. And a fixing member including two fixing portions facing each other at a predetermined distance in the thickness direction of the actuator spring from a portion of the second support portion on the second spring side, and the two fixing portions are The piezoelectric element is disposed at a position sandwiching a longitudinal center axis of the actuator spring, and the piezoelectric element is configured to be driven to slide in a direction orthogonal to a thickness direction of the actuator spring, and the piezoelectric elements slide with each other. The two end faces to be driven are sandwiched between the portion of the second support portion facing the fixed portion and the fixed portion, and the portion of the second support portion and the portion of the fixed portion are sandwiched between the fixed portion and the fixed portion. 18. The magnetic head positioning mechanism according to claim 17 , wherein the magnetic head positioning mechanism is fixed to each position. 20. The coarse actuator section supports a plurality of fine actuator sections, and the displacement of the fine actuator section in the seek direction by the coarse actuator section collectively includes the plurality of fine actuator sections. 20. The magnetic head positioning mechanism according to claim 1 , wherein the magnetic head positioning mechanism is configured to perform the operation. 21. The two piezoelectric elements are disposed on the actuator spring at a position sandwiching a longitudinal center axis of the actuator spring, and one end is fixed to a position of the first support portion. An end is fixed to the location of the second support, and a drive gap for driving the piezoelectric element is formed between the location of the first support and the location of the second support. Claim 1, characterized in that :
8. The magnetic head positioning mechanism according to 3 or 7 .