JPH0620415A - Head positioning mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] A head positioning mechanism for positioning a head mounted via a head support spring to a head arm that is reciprocally moved by a linear actuator and a rotary actuator in the radial direction of a disk. An object of the present invention is to provide a head positioning mechanism that enables high-speed positioning. In the vicinity of a head support spring mounting portion of a head arm 1, at least a substantially rectangular through hole 1a having two sides substantially along the axis of the head arm 1 and two sides substantially orthogonal to the axis of the head arm is provided. The base end portion of the head support spring 3 is attached to one of the two sides that are provided at one location and substantially orthogonal to the axis of the head arm 1, and the cutouts 1c and 1d are provided on at least one side of the through hole 1a. The cutouts 1c and 1d are configured so that the laminated piezoelectric actuators 4 and 5 using the vertical effect are press-fitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head positioning mechanism for positioning a head mounted on a head arm which is reciprocally moved by a linear actuator and a rotary actuator in a disk radial direction via a head support spring.

In recent years, with the increase in track density in magnetic disk devices, there has been a demand for a head positioning mechanism that holds down the amount of off-track.

[0003]

2. Description of the Related Art Generally, a head positioning control method in a magnetic disk device is roughly classified into a method of performing open loop control using a step motor or the like as a head positioning actuator, and a voice coil motor (VC).
There is a method of performing closed loop control using M) or the like.

In the open loop control system, the structure of the actuator and its control circuit are simple, but the positioning of the head during data read / write shifts in the radial direction of the disk due to thermal deformation or the like, so-called off-track. It is difficult to increase the track density because it cannot be corrected.

On the other hand, in the closed loop control system, since the head is positioned by the servo information recorded in advance on the disk, a higher track density can be achieved.

[0006]

By the way, in the closed loop control system of the type in which a plurality of magnetic heads are arranged on one surface of the disk, the area used by one of the magnetic heads or the HDA is conventionally used. In the case of the type with multiple actuators (head disk assembly), servo information is written on one disk surface for each actuator, and the servo surface is used to control the positioning of the magnetic head, and the other surfaces are used as data. The servo method of the servo surface used as the recording surface was the mainstream. However, in the case of this method, when the spindle on the disk side, the shaft on the actuator side, or the like relatively tilts or locally deforms due to thermal deformation of these supporting structures during data read / write, the data head and the associated data head are interlocked. There is a problem that the recording density cannot always be easily increased because the servo head may be off-track due to the deviation between the data surface and the servo surface.

Therefore, in order to increase the recording density, the actuator is required to have a function of positioning the head at high speed and with high accuracy with respect to the disk.

Generally, the access operation by the actuator is performed by a coarse (coarse) mode for moving the head to a target track of the disk at a high speed and a fine (fine) mode for causing the head to follow the target track. .

An actuator operating in the coarse mode is required to be able to generate a large acceleration over the entire movement stroke of the head. Therefore, the propulsive force per supplied drive current is increased, and the actuator of the movable part is increased. It is necessary to obtain a large acceleration by reducing the mass.

On the other hand, in the fine mode, the operating distance of the head is short and a large acceleration is not required, but a wide control band and a structure with high rigidity are required to perform highly accurate positioning.

Of course, even in the coarse mode, since it is not a completely open control, it is necessary to have high rigidity, but a wider control band than that in the fine mode is not required, and vibration occurs in the fine mode following the coarse mode. It should be a level that does not leave the like.

Further, in the coarse mode which requires a large output, it is necessary to flow as large a current as possible in both directions. Therefore, the power amplifier for driving this is composed of an H-bridge circuit and the direction of the current is switched by switching. I often change. Therefore, in such an amplifier, there is a problem that it becomes difficult to control a very small displacement in the fine mode due to the dead band and the like.

The present invention has been made in view of the above problems, and an object thereof is to provide a head positioning mechanism capable of positioning the head with high accuracy and at high speed.

[0014]

FIG. 1 is a view for explaining the principle of the invention of claim 1, (a) is a plan view, (b) is a front view, and FIG. 2 is the principle of the invention of claim 5. (A) is a plan view and (b) is a front view.

First, in FIG. 1, 1 is a head arm which is reciprocally moved in the disk radial direction by a linear actuator (not shown), and 2 is a head which is attached to the head arm 1 via a head support spring 3.

In the vicinity of the mounting portion of the head support spring 3 of the head arm 1, a substantially rectangular through hole 1a having two sides substantially along the axis of the head arm 1 and two sides substantially orthogonal to the axis of the head arm 1 is formed. At least one place is provided. In addition,
In this principle diagram, two substantially rectangular through holes 1a are provided.

The base end portion of the head support spring 3 is attached to one of the two sides of the through hole 1a substantially orthogonal to the axis of the head arm 1, and the through hole 1a is cut at least on one side. Notches 1c and 1d are provided.

Then, the laminated piezoelectric actuators 4, 5 using the vertical effect are press-fitted into the notches 1c, 1d.

In FIG. 2, 6 is a head arm that is reciprocated by a rotary actuator (not shown) in the disk radial direction, and 7 is a head that is attached to the head arm 6 via a head support spring 8.

In the vicinity of the mounting portion of the head support spring 8 of the head arm 6, a substantially rectangular through hole 6a having two sides substantially along the axis of the head arm 6 and two sides substantially orthogonal to the axis of the head arm 6 is formed. Is provided.

The base end of the head support spring 8 is attached to one of the two sides of the through hole 6a which are substantially orthogonal to the axis of the head arm 6.

Then, on two sides of the through hole 6a substantially along the head arm, there are provided laminated piezoelectric actuators 9 and 10 using the lateral effect.

[0023]

In the head positioning mechanism of the first aspect of the invention, when the laminated piezoelectric actuators 4, 5 using the vertical effect are applied, the laminated piezoelectric actuators 4, 5 are applied.
Expands and contracts according to the applied voltage, and the head support spring 3 also rotates according to the applied voltage. By this rotation, the head 2 is moved and the head 2 is positioned.

In the head positioning mechanism of the fifth aspect of the invention, the laminated piezoelectric actuator 9 using the lateral effect,
When 10 is applied respectively, the laminated piezoelectric actuators 9 and 10 expand and contract according to the applied voltage, and the head support spring 8
Also rotates according to the applied voltage. By this rotation, the head 7 moves, and the head 7 is positioned.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. 3A and 3B are views for explaining an essential part of the first embodiment of the present invention. FIG. 3A is a plan view, FIG. 3B is a front view, and FIG. 4 is a magnetic disk provided with the head positioning mechanism shown in FIG. 6 is a plan view of the apparatus, FIG. 5 is a front sectional view of FIG.
FIG. 3A is a diagram illustrating a main part of a second embodiment of the present invention, in which FIG.
Is a plan view, (b) is a front view, FIG. 7 is a view for explaining a main part of a third embodiment of the present invention, (a) is a plan view, (b) is a front view, and FIG. 8 is the present invention. 4A is a plan view, FIG. 9B is a front view, and FIG. 9 is a plan configuration diagram of a magnetic disk device provided with the head positioning mechanism shown in FIG. FIG. 10 is a front cross-sectional configuration diagram in FIG. 9, and FIG. 11 is a diagram illustrating a main part of a fifth embodiment of the present invention.
(A) is a plan view, (b) is a front view, FIG. 12 is a diagram for explaining an essential part of a sixth embodiment of the present invention, (a) is a plan view,
FIG. 13B is a front view, and FIG. 13 is a diagram illustrating a seventh embodiment of the present invention.

First, the first aspect of the present invention will be described with reference to FIGS.
An example will be described. In the figure, a shaft 24 is rotatably attached to the bottom surface and the top surface of an enclosure 21 that seals the magnetic disk device via bearings 22 and 23. This shaft 24 has a spacer 2
A plurality of discs 26 (in this embodiment, 7
It is attached. On the other hand, a spindle motor 27 that rotationally drives the shaft 24 at high speed (for example, 3600 rpm) is attached to the outer surface of the bottom surface of the enclosure 21.

On the other hand, a linear actuator 28 is provided on the bottom surface of the enclosure 21 so as to be movable in the radial direction of the disk 26 (the arrow direction in FIGS. 4 and 5).
Is provided. The linear actuator 28 includes a plurality of head arms 32 extending in the direction between the disks 26.
(6 in this embodiment) are formed. A head 34 that reads / writes data from / to each disk 26 is attached to the tip of the head arm 32 via a head support spring 33.

Next, the head positioning mechanism of the disk device of this embodiment will be described with reference to FIG.

A substantially rectangular hole 40 is formed at the tip of the head arm 32. The hole 40 has a first side 40a, a second side 40b, which are substantially along the axis of the head arm 32,
And a third side 40 that is substantially orthogonal to the axis of the head arm 32.
c and the fourth side 40d, and the head support spring 3 is provided on the third side 40c which is the side on the tip end side of the head arm 32.
3 is attached.

The notch 4 is formed on the second side 40b.
0e is formed, and the laminated piezoelectric actuator 41 using the vertical effect is press-fitted into the notch 40e.

A vent portion 40f is formed on the first side 40a. Next, the operation of the above configuration will be described. The disk 26 is rotationally driven by a spindle motor 27. When the linear actuator 28 is moved in the arrow direction, each head 34 moves to a desired track on each disk 26, and data reading / writing is performed.

By the way, in such a magnetic disk device, each head 34 is affected by temperature, aging, and the like.
A relative positional deviation (off-track) occurs between the disk and each disk 26. If there is such a displacement,
A voltage corresponding to the displacement is applied to the laminated piezoelectric actuator 41. By applying to the laminated piezoelectric actuator 41, the laminated piezoelectric actuator 41 expands and contracts in the axial direction of the head arm 32. On the other hand, the bent portion 40f is formed on the first side 40a, and the bending rigidity is weakened. Therefore, when the laminated piezoelectric actuator 41 contracts, the first side 40a bends, and each head 34 can be positioned.

According to the above construction, by adjusting each head arm 32, each head 34 can be positioned with high accuracy and at high speed.

Next, a second embodiment of the present invention will be described with reference to FIG. The only difference between this embodiment and the first embodiment described above is the head positioning mechanism, and the other parts are the same, so a description of the other parts will be omitted. In the figure, a substantially rectangular hole 50 is formed at the tip of the head arm 32. The hole 50 includes a first side 50a and a second side 50b that are substantially along the axis of the head arm 32, and a third side 50c and a fourth side 50 that are substantially orthogonal to the axis of the head arm 32.
The head support spring 33 is attached to the third side 50c, which is a side of the head arm 32 on the side of the tip portion of the head arm 32.

The notch 5 is formed on the fourth side 50d.
0e is formed, and the laminated piezoelectric actuator 51 using the vertical effect is press-fitted into the notch 50e.

Next, the operation of the above configuration will be described. When the position of the head is adjusted, a voltage corresponding to the displacement is applied to the laminated piezoelectric actuator 51. By applying the voltage to the laminated piezoelectric actuator 51, the laminated piezoelectric actuator 51 expands and contracts in the direction orthogonal to the axial direction of the head arm 32. By this expansion and contraction, the first side 50 of the hole 50
The distance between a and the second side 50b is opened or narrowed, and each head arm 32 moves in the direction of the arrow in FIG. 6 to position each head 34.

According to the above construction, each head 34 can be positioned with high accuracy and at high speed.

Next, a third embodiment of the present invention will be described with reference to FIG. The only difference between this embodiment and the first and second embodiments described above is the head positioning mechanism, and the other parts are the same, so a description of the other parts will be omitted. In FIG. 7, a substantially rectangular hole 61 is formed at the tip of the head arm 60.
And 62 are bored along the axial direction of the head arm 60.

The hole 61 has a first side 61a and a second side 61b that are substantially along the axis of the head arm 60, and a third side 61c and a fourth side 61d that are substantially orthogonal to the axis of the head arm 60.
And the third side which is the side on the tip end side of the head arm 60.
A head support spring 33, to which the head 34 is attached at the tip, is attached to the side 61c.

Similarly, the hole 62 is defined by the head arm 60.
A first side 62a, a second side 62b, which are substantially along the axis of
The head 34 is attached to the tip of the third side 62c, which is a side on the tip end side of the head arm 60, which is composed of a third side 62c and a fourth side 62d that are substantially orthogonal to the axis of the head arm 60. A head support spring 33 is attached.

A notch 61e is formed on the second side 61b of the hole 61, and a laminated piezoelectric actuator 63 using the vertical effect is press-fitted into the notch 61e. Further, a vent portion 61f is formed on the first side 61a.

Similarly, a notch 62e is formed on the first side 62a of the hole 62, and a laminated piezoelectric actuator 64 using the vertical effect is press-fitted into the notch 62e. Further, a vent portion 62f is formed on the second side 62b.

To correct the displacement of the head 34, a voltage corresponding to the displacement is applied to the laminated piezoelectric actuators 63 and 64. Multilayer piezoelectric actuator 63, 6
4 is applied to the laminated piezoelectric actuator 6
3, 64 expand and contract in the axial direction of the head arm 60. On the other hand, the bent portions 61f and 62f have weak bending rigidity. Therefore, when the laminated piezoelectric actuators 63 and 64 contract, the bent portions 61f and 62f bend,
Positioning of each head 34 can be performed.

According to the above construction, by adjusting the position of each head arm 60, each head 34 can be moved with high accuracy.
Moreover, positioning can be performed at high speed.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. The same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted. In the figure, a shaft 70 is attached to the bottom surface and the top surface of the enclosure 21. The rotary actuator 7 is attached to the shaft 70 via bearings 71 and 72.
3 is rotatably mounted. The actuator 73 is formed with a plurality of head arms 74 (six in this embodiment) extending in the direction between the disks 26. At the tip of the head arm 74, the head support spring 3
Read / write data to / from each disk 26 via
A head 34 for writing is attached.

A magnetic circuit 75 is disposed on the bottom surface of the enclosure 21 and at the back of the rotary actuator 73. The rotary actuator 73 has a coil 7 disposed in the magnetic gap of the magnetic circuit 75.
6 is attached. A moving coil type force motor (VCM; voice coil motor) is formed by the magnetic circuit 75 and the coil 76.
By applying an electric current to the coil 6, thrust is generated in the coil 76, and the rotary actuator 73 is rotationally driven with respect to the shaft 70.

Next, the head positioning mechanism of the disk device of this embodiment will be described with reference to FIG.

A substantially rectangular hole 80 is formed at the tip of the head arm 74. The hole 80 has a first side 80a, a second side 80b, which are substantially along the axis of the head arm 74,
And a third side 80 that is substantially orthogonal to the axis of the head arm 74.
c and the fourth side 80d, and the head support spring 3 is provided on the third side 80c which is the side on the tip end side of the head arm 74.
3 is attached.

Then, the first side 40a and the second side 40
Stacked piezoelectric actuators 81 and 82 using the lateral effect are attached to the side surface of b. Further, the head arm 7 is provided on the side surface portions of the first side 40a and the second side 40b.
A plurality of slits 83 extending in a direction substantially perpendicular to the axis of No. 4 are provided.

Next, the operation of the above configuration will be described. The disk 26 is rotationally driven by a spindle motor 27. When the rotary actuator 73 is rotationally driven, each head 34 moves to a desired track on each disk 26, and data reading / writing is performed.

When the position of the head 34 is adjusted, a voltage corresponding to the displacement is applied to the laminated piezoelectric actuators 81 and 82. By applying to the laminated piezoelectric actuators 81 and 82, the laminated piezoelectric actuators 81 and 8
2 extends and contracts in the axial direction of the head arm 74. On the other hand, the first
Since the slits 83 are formed on the sides 80a and 80b, the first side 80a and the second side 80b can be expanded and contracted in the axial direction of the head arm 74. Therefore,
By expanding and contracting the laminated piezoelectric actuators 81 and 82, the first side 80a and the second side 80b expand and contract, respectively, and each head 34 can be positioned.

According to the above arrangement, each head 34 can be positioned with high accuracy and at high speed.

Next, a fifth embodiment of the present invention will be described with reference to FIG. In this embodiment, the same parts as those in the fourth embodiment are designated by the same reference numerals, and their description will be omitted. In the figure, the first side 80a of the hole 80 of the head arm 74,
The upper and lower surfaces of the second side 80b are laminated piezoelectric actuators 85, 86, 87, 88 using the lateral effect, respectively.
(The laminated piezoelectric actuator 88 is not shown) is attached.

Next, the operation of the above configuration will be described. When the position of the head 34 is adjusted, a voltage corresponding to the displacement is applied to the laminated piezoelectric actuators 85 to 88. By applying to the laminated piezoelectric actuators 85 to 88,
The laminated piezoelectric actuators 85 to 87 are the head arm 7
4, the first and second sides 80a and 80b also expand and contract by the expansion and contraction of the laminated piezoelectric actuators 85 to 88, so that each head 34 can be positioned.

According to the above configuration, the twist of each head arm 74 can be corrected, and the offset correction can be performed for each head 34.

Next, a sixth embodiment of the present invention will be described with reference to FIG. This embodiment is the first side 80 of the fifth embodiment.
a, slits 90 extending in the other surface direction are provided on the upper surface and the lower surface of the second side 80b.

According to this configuration, the first side 80a and the second side 80a
Since the slit 90 is provided on the side 80b, the first side 80a and the second side 80b are more easily expanded and contracted in the axial direction of the head arm 74 than in the fifth embodiment. Therefore, the same effect as that of the fifth embodiment can be obtained, and the head arm 74 can be expanded and contracted with less energy.

Next, a seventh embodiment of the present invention will be described with reference to FIG. The head arms of the first to sixth embodiments use the in-line type head support spring mechanism, but in the present embodiment, the head arm using the dog leg type head support spring mechanism will be described. .

In the figure, a substantially rectangular hole 91 is formed at the tip of the head arm 90. This hole 91
Is composed of a first side 91a, a second side 91b that is substantially along the axis of the head arm 90, and a third side 91c and a fourth side 91d that are substantially orthogonal to the axis of the head arm 90. A dog leg type head support spring 92 having a head 93 attached to the tip is attached to a third side 91c which is the tip side of the.

Then, the first side 91a and the second side 91
Multilayer piezoelectric actuators 94 and 95 using the lateral effect are attached to the side surface of b.

When the position of the head 34 is adjusted, a voltage corresponding to the displacement is applied to the laminated piezoelectric actuators 94 and 95. By applying to the laminated piezoelectric actuators 94 and 95, the laminated piezoelectric actuators 94 and 9
5 extends and contracts in the axial direction of the head arm 90. When the laminated piezoelectric actuators 94 and 95 expand and contract, the first
The side 90a and the second side 90b can be expanded and contracted to position each head 93.

According to the above construction, each head 93 can be positioned with high accuracy and at high speed.

[0063]

As described above, according to the present invention, it is possible to realize the head positioning mechanism capable of positioning the head with high accuracy and at high speed.

[Brief description of drawings]

FIG. 1 is a principle diagram of the invention of claim 1;

FIG. 2 is a principle view of the invention of claim 5;

FIG. 3 is a diagram illustrating a main part of the first embodiment of the present invention,
(A) is a plan view and (b) is a front view.

4 is a plan configuration diagram of a magnetic disk device provided with the head positioning mechanism shown in FIG. 3. FIG.

5 is a front cross-sectional configuration diagram in FIG.

FIG. 6 is a diagram illustrating a main part of a second embodiment of the present invention,
(A) is a plan view and (b) is a front view.

FIG. 7 is a diagram illustrating a main part of a third embodiment of the present invention,
(A) is a plan view and (b) is a front view.

FIG. 8 is a diagram illustrating a main part of a fourth embodiment of the present invention.

FIG. 9 is a plan configuration diagram of a magnetic disk device provided with the head positioning mechanism shown in FIG.

10 is a front cross-sectional configuration diagram in FIG.

11A and 11B are views for explaining a main part of a fifth embodiment of the present invention, in which FIG. 11A is a plan view and FIG. 11B is a front view.

12A and 12B are views for explaining a main part of a sixth embodiment of the present invention, in which FIG. 12A is a plan view and FIG. 12B is a front view.

FIG. 13 is a diagram illustrating a seventh embodiment of the present invention.

[Explanation of symbols]

 1,6 head arm 1a, 6a through hole 2,7 head 3,8 head support spring 4,5,9,10 laminated piezoelectric actuator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihiro Arikawa 5400, Omori, Higashine, Higashine, Higashine, Yamagata Prefecture 2 Yamagata Fujitsu Limited

Claims (9)

[Claims] 1. A head positioning mechanism for positioning a head (2) mounted on a head arm (1) reciprocally moved by a linear actuator in a disk radial direction via a head support spring (3), said head comprising: In the vicinity of the head support spring mounting portion of the arm (1), a substantially rectangular through hole (1a) having two sides substantially along the axis of the head arm (1) and two sides substantially orthogonal to the axis of the head arm (1a). ) Is provided at least at one place, and one of the two sides substantially orthogonal to the axis of the head arm (1) is provided.
A base end portion of the head support spring (3) is attached to the side, and a cutout (1) is formed on at least one side of the through hole (1a).
c, 1d), and a stacked piezoelectric actuator (4, 5) using a vertical effect is press-fitted into the notch (1c, 1d). 2. The through hole is provided at two places through the shaft of the head arm, and the notch is provided at each of outer sides of the two through holes along the axis of the head arm. The head positioning mechanism according to claim 1, wherein a piezoelectric actuator is press-fitted into these notches. 3. The through hole is provided at one place in the vicinity of a head support spring of the head arm, and one of two sides of the through hole along the axis of the head arm has a notch and the other side. 2. The head positioning mechanism according to claim 1, wherein a vent portion is provided in the notch, and a piezoelectric actuator is press-fitted into the notch. 4. The through hole is provided at one location near the head support spring of the head arm, and the side of the through hole that is substantially orthogonal to the axis of the head arm is not attached to the head arm support spring. The head positioning mechanism according to claim 1, wherein a notch is provided, and a piezoelectric actuator is press-fitted into the notch. 5. A head positioning mechanism for positioning a head (7) mounted on a head arm (6) reciprocally moved by a rotary actuator in the disk radial direction via a head support spring (8), Near the head support spring mounting portion of the arm (6), a substantially rectangular through hole (6a) having two sides substantially along the axis of the head arm (6) and two sides substantially orthogonal to the axis of the head arm (6a). ) Is provided, and the base end portion (8) of the head support spring is attached to one of the two sides substantially orthogonal to the axis of the head arm, and the base end portion (8) is attached to the two sides substantially along the head arm (6). A head positioning mechanism comprising a laminated piezoelectric actuator (9, 10) using the effect. 6. The head positioning mechanism according to claim 5, wherein the piezoelectric actuator is provided on side surfaces of two sides substantially along the axis of the head arm. 7. The head positioning mechanism according to claim 6, wherein a side surface portion substantially along the axis of the head arm is provided with a slit extending in a direction substantially perpendicular to the axis of the head arm. 8. The head positioning mechanism according to claim 5, wherein the piezoelectric actuator is provided on an upper surface portion and a lower surface portion of two sides substantially along the axis of the head arm. 9. The positioning of the head according to claim 8, wherein slits are formed on the upper surface and the lower surface of the two sides substantially along the head arm so as to extend in the other surface direction. mechanism.