JPH11297011A - Magnetic head positioning device and magnetic disk drive using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the magnetic head positioning device which enables fast and accurate tracking control, track jump control, etc., without causing vibration and the magnetic disk drive with high recording density. SOLUTION: This positioning device is provided on a fixation side so that magnets 12a and 12b are divided into two magnetized areas along and the N poles and S poles are paired across a rotary shaft 11 at equal distances. Further, a coil 13 is provided on a rotation side while surrounding the rotary shaft 11 so as to face the N poles and S poles. A couple of forces are generated with a force F generated through the interaction between the current I flowing to the coil 13 and magnetic fields of magnetic flux density B by the magnets 12a and 12b and an actuator 1 is rotated to position a magnetic head. The rotation side of the actuator 1 is supported on the fixation side rotatably by a hinge spring 18 formed of a leaf spring member.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head positioning device suitable for large-capacity, high-density recording and excellent in tracking and track jump control, and a magnetic disk drive using the same.

[0002]

2. Description of the Related Art A conventional magnetic disk device (so-called hard disk device) will be described with reference to FIGS. Here, FIG. 8 shows a configuration of a general magnetic disk drive, and FIG. 9 is a diagram for explaining a rotating force of a magnetic head positioning device used in the magnetic disk drive shown in FIG. FIG. 10 is a diagram for explaining the generation of vibration on the rotation axis of the magnetic head positioning device shown in FIG. In the following, the “magnetic head positioning device” is referred to as an “actuator”.

Conventionally, a magnetic disk drive 30 shown in FIG.
Is well known. The magnetic disk drive 30 includes a spindle motor 32 mounted on a housing 31.
And the disk 3 attached to the spindle motor 32
3 and a rotary actuator 34 and the like.
Rotate in the direction shown by 3.

The rotary actuator 34 of the magnetic disk drive 30 has a slider 35 on which a magnetic head (not shown) is mounted, and a spring 35 which mounts the slider 35 at the tip and presses the slider 35 toward the disk 33 with a predetermined load. , An arm 37 that supports the suspension 36 and has a specified actuator length, and a yoke 3
8, a driving unit including a magnet 39 and a coil 40, and is fixed to the housing 31 via a rotating shaft 41. In FIG. 8, the coil 40 is provided on the rotating side.

As shown in FIG. 9, the rotary actuator 34 is rotated by a force F generated by an interaction between a current flowing through the coil 40 and a magnetic field having a magnetic flux density B formed by the yoke 38 and the magnet 39. It rotates around 41. The magnetic field is formed so that one side of the coil 40 generating the force F is directed from the back surface to the front surface of the paper, and the other side is directed from the front surface to the back surface of the paper. As a result, a rotational force in the same direction is generated on each side corresponding to the direction of the current I, and the arm 37 is rotated by the rotational force, and the magnetic head mounted on the slider 35 is moved to the track of the disk 33 by the track. The information is written by positioning at the position, and the reproduction is performed.

By the way, in recent years, higher recording density has progressed,
That is, the track width and the track pitch are narrowed, and it has become difficult to apply tracking servo with the above-described conventional rotary actuator. That is, the lubricating grease of the bearing used for the rotary shaft of the rotary actuator is required for accurate tracing of the track, jumping to the adjacent track, and high-speed operation with a small amplitude required for stabilization. This is because the viscous resistance of the rotary actuator, the weight of the rotary actuator, the moment of inertia, and the like have a large effect.

[0007] In addition to the rotational force, the coil 40 generates a force acting on the rotary shaft of the rotary actuator so as to tilt the rotary shaft, thereby causing a change in the direction of the current I for positioning the magnetic head. Corresponding vibration is occurring.

The generation of this vibration will be described with reference to FIG. The coil 40 has a side including the point Pa and a side including the point Pb.
In the side including the point a, the surface goes from the back side to the front side, and in the side including the point Pb, the side goes from the front side to the back side. Also, it is assumed that the extension lines of the two sides intersect at a point O1, and that the rotation shaft 41 of the rotary actuator is provided at a point O2 closer to the coil 40 than the point O1.

In this state, when a current I in the direction indicated by the arrow flows through the coil 40, a force Fa1 is generated at the point Pa in the direction perpendicular to the side on the paper. This force Fa1 is a force Fa2 for rotating the rotary shaft 41 at the point O2.
And a force Fa3 on a line segment Pa-O2 perpendicular to the force Fa2. Similarly, a force Fb1 is generated at the point Pb, which is decomposed into a force Fb2 and a force Fb3. Force Fa
The force Fa3 and the force Fb3 become a resultant force Fc at the point O2, and the force Fa3 and the force Fb3 act as a resultant force at the point O2. When the current I is in the opposite direction, the resultant force Fc is also directed in the opposite direction, and eventually, vibration synchronized with the current I that changes for positioning the magnetic head is generated on the rotating shaft 41. The same applies to the force generated at any point on the side, and these are combined to generate a large vibration force.

When the rotary shaft 41 is provided at the point O1 where the extension lines of the two sides of the coil intersect, the line segment Pa-O
1 and the coil on the line segment Pb-O1 can surely obtain only rotational force, but since the coil 40 actually has a width, the coil 40 has a width, so that the coil 40 has a width on the line segment Pa-O1 and the line segment Pb-O1. The force generated in the portion that is not above includes the component that generates the above-described vibration, and the generation of the vibration cannot be avoided. This vibration made it difficult to control precise tracing of tracks, jumps to adjacent tracks, and stabilization. Further, when the rotating shaft 41 is provided at the point O1,
The moment of inertia is increased as compared with the case where it is provided at the point O2, and the response is reduced.

[0011]

SUMMARY OF THE INVENTION Accordingly, the present invention is directed to a magnetic disk drive with a high recording density, which eliminates a vibration component acting on a rotating shaft of a rotary actuator and acting to tilt the rotating shaft, thereby achieving high-speed operation. It is an object of the present invention to provide a magnetic head positioning device that enables accurate and accurate track tracing and track jumping, and a magnetic disk device using the same.

[0012]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above problems, and has a magnetic head for recording and reproducing information on an information recording medium mounted on a rotating side. In a magnetic head positioning device mounted on a fixed side via a rotating shaft, a coil is arranged around the rotating shaft on the rotating side on one of the rotating side and the fixed side, and on the other, A magnetic head positioning device includes a plurality of magnets that generate a couple around the rotation axis so as to coincide with sides of the coil that oppose each other across the rotation axis.

[0013] A coil is arranged on one of the rotating side and the fixed side so as to surround the rotating shaft on the rotating side, and is opposed to the other one with the rotating axis of the coil interposed therebetween. A magnetic head using a leaf spring-like member as support means for providing a plurality of magnets that generate couples about the rotation axis in alignment with the sides and rotatably supporting the rotating side to the fixed side. Construct a positioning device.

A two-stage magnetic head positioning device comprising a first-stage coarse-movement rotating mechanism and a second-stage fine-movement rotating mechanism equipped with a magnetic head,
The second-stage rotating mechanism rotates the magnetic head to one of the rotating side of the second-stage rotating mechanism and the rotating side of the first-stage rotating mechanism. A coil is disposed around the second-stage rotation axis to be formed, and the other side is aligned with the opposite side of the coil with the second-stage rotation axis interposed therebetween. A plurality of magnets for generating a force are provided, and a magnetic head positioning using a leaf spring-like member as a support means for rotatably supporting the second stage rotating side to the first stage rotating side. Configure the device.

A two-stage magnetic head positioning device comprising a first-stage coarse rotation mechanism and a second-stage fine-movement rotation mechanism equipped with a magnetic head,
The second-stage rotating mechanism rotates the magnetic head to one of the rotating side of the second-stage rotating mechanism and the rotating side of the first-stage rotating mechanism. A coil is disposed around the second-stage rotation axis to be formed, and the other side is aligned with the opposite side of the coil with the second-stage rotation axis interposed therebetween. A plurality of magnets for generating a force are provided, and the first-stage rotating mechanism is provided on one of a rotating side and a fixed side of the first-stage rotating mechanism.
A coil is arranged around the first-stage rotation axis for rotating the magnetic head, and the other is aligned with the opposite side of the coil across the first-stage rotation axis, Along with providing a plurality of magnets that generate couples around the rotation axis,
A magnetic head positioning device using a leaf spring-like member as a supporting means for rotatably supporting the second stage rotating side to the first stage rotating side is constituted.

Further, a magnetic disk drive is constituted by using any one of the magnetic head positioning devices described above, thereby solving the above-mentioned problems.

According to the arrangement and configuration of the coils and magnets described above, a vibration generated on the rotating shaft is reduced, and a magnetic head positioning device having a small moment of inertia is formed. Accordingly, high-speed and accurate track tracing and track jumping of the magnetic head can be performed.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head positioning device according to the present invention is of a rotary type, and a driving force is obtained by a couple generating mechanism symmetrically formed around a rotation axis. It features high-speed response by reducing the moment and improved accuracy of tracking control of the magnetic head by reducing the vibration generated on the rotating shaft. In addition, high-speed response, high reliability, and high recording are achieved by using this magnetic head positioning device. A magnetic disk device having an excellent density is constituted.

Next, an embodiment of the present invention will be described in detail. In the drawings to be referred to, the X-axis direction is the track jump (seek) direction, the Y-axis direction is the arm longitudinal direction, and the Z-axis direction is the axial direction of the rotation axis.

<First Embodiment> A first embodiment will be described with reference to FIGS. Here, FIG. 1 is a perspective view showing a configuration of a first embodiment according to the present invention, and FIG. 2 is a diagram showing a configuration of a driving unit of this embodiment. FIG. 3 shows a structure of a hinge spring used in the present invention.
FIG. 4 is a perspective view showing an example, and FIG. 4 is a view for explaining the operation of the hinge spring shown in FIG.

The actuator 1 according to the first embodiment shown in FIG. 1 includes a rotating shaft 11, magnets 12a and 12b provided on a fixed side, a coil 13 provided around the rotating shaft 11, and a coil 13. A base plate 14 fixedly attached to the rotating shaft 11, an arm 15 having a predetermined length attached to the base plate 14, a suspension 16 attached to the arm 15, and a slider mounted with a magnetic head attached to the tip of the suspension 16 17 and a hinge spring 18 for rotatably supporting a movable portion formed by these components on a fixed side.

The base plate 14 is opposed across the rotating shaft 11 so as to balance the rotational moments before and after the rotating shaft 11, that is, to correspond to the rotating moment formed by the arm 15, the suspension 16 and the like. It has a shape protruding to the side.

Each of the magnets 12a and 12b is divided into two magnetized regions in the longitudinal direction, and the magnetic field is magnetized in the direction toward the upper surface and the lower surface. That is, in one region, the upper surface is an N pole and the lower surface is an S pole, and in the other region, the upper surface is an S pole and the lower surface is an N pole. Further, the magnets 12a and 12b are arranged such that the N pole and the S pole are paired. Therefore, the direction of the magnetic field on the coil 13 is below the N pole of the magnets 12a and 12b (that is, the S pole is
Is facing upward), and downward on the lower side of the S pole (that is, the N pole faces the coil 13). The magnets 12a and 12b are arranged at equal distances on both sides of the rotating shaft 11.

The generation of a force when the current I flows through the coil 13 in the state described above will be described. As shown in FIG. 2, the force F generated on the coil 13 at the position facing the magnet 12a and the force F generated on the coil 13 at the position facing the magnet 12b have the same magnitude and are in opposite directions. The position where it occurs is a position symmetrical with respect to the rotation axis 11. Therefore, these forces form a couple with the rotating shaft 11 interposed therebetween, and the other components of the force, that is, the forces that generate vibration as described in the related art are canceled out and do not exist. Due to this couple, the turning side to which the coil 13 is fixed turns in the direction shown by the arrow R11, and when the direction of the current I is reversed, it turns in the direction opposite to the arrow R11.

Next, the hinge spring 18 shown in FIG. 3 will be described. The hinge spring 18 that connects the fixed side and the rotation side of the actuator is provided on two sides in the X-axis direction of the rectangular movable surface 18a that is perpendicular to the Z axis and fixed to the base plate 14, and the movable surface 18a. A spring portion 18b that rises in the Z-axis direction, and two fixing surfaces 18c that are perpendicular to the Z-axis and extend in the X-axis direction from a predetermined height of the spring portion 18b. The connection portion 18c is provided with a slit 18d of a predetermined length. At the center of each of the fixing surfaces 18c, there is provided a hole 18e used when attaching to the arm 15.

The operation of the above-described hinge spring 18 will be described with reference to FIG. FIG. 4A shows a stationary state where no force is applied. When the force F is applied to form a couple as described above, as shown in FIG.
The movable surface 18a deforms the spring portion 18b and is turned in the direction indicated by the arrow R11. When current flows in the opposite direction, the movable surface 1
8a rotates in the direction opposite to the direction of the arrow R11, and when the current stops, the movable surface 18a returns to the initial position by the action of the spring portion 18b. Therefore, the rotation of the arm 15, the suspension 16, and the slider 17 fixed to the movable surface 18a is controlled, and the magnetic head mounted on the slider 17 can be positioned.

<Second Embodiment> Next, as a second embodiment, an embodiment comprising a first-stage driving unit for coarse movement and a second-stage driving unit for fine movement equipped with a magnetic head. The magnetic head positioning device will be described with reference to FIGS. FIG. 5 is a perspective view showing the configuration of a fine movement drive unit used in the second embodiment, and FIGS. 6 and 7 are perspective views of an actuator according to the second embodiment.

First, the second-stage fine movement driving section 4 shown in FIG. 5 will be described. The configuration of the fine movement drive unit 4 is substantially the same as that of the actuator 1 described in the first embodiment.
As shown in FIG. 5, the rotating shaft 21 and magnets 22a and 22 provided on the rotating side of a coarse movement driving unit described in detail later.
b, a coil 23 provided around the rotating shaft 21 for generating a rotating power, a base plate 24 to which the coil 23 is fixed and attached to the rotating shaft 21,
, A slider 17 mounted with a magnetic head, mounted on the tip of the suspension 16, and a hinge spring 28 that rotatably supports a component made of these components on a rotary portion of a coarse drive unit. It is configured.

The base plate 24 projects to the opposite side with respect to the rotary shaft 21 so as to balance the rotational moment before and after the rotary shaft 21, that is, to correspond to the rotational moment formed by the suspension 16 and the like. Shape. The hinge spring 28 has the same shape as the above-mentioned hinge spring 18 and has the same function.

As shown in FIG. 5, each of the magnets 22a and 22b is divided into two magnetized regions in the longitudinal direction, and the magnetic field is magnetized in the direction toward the upper surface and the lower surface. That is, in one region, the upper surface is an N pole and the lower surface is an S pole, and in the other region, the upper surface is an S pole and the lower surface is an N pole. Further, the magnets 22a and 22b are arranged such that the N pole and the S pole are paired. Therefore, the direction of the magnetic field on the coil 23 is below the N pole of the magnet 22a and the magnet 22b (that is,
(The south pole is opposed to the coil 23).
The lower side of the south pole (that is, the north pole faces the coil 23)
Then it is downward. Further, the magnets 22a and 22b are arranged at equal distances on both sides of the rotating shaft 21.

When the current I is applied to the coil 23 in the above-described state, the coil 2 at the position facing the magnet 22a
3 and the force F generated in the coil 23 at the position facing the magnet 22b are the same and opposite in direction, and the generated positions are symmetrical with respect to the rotating shaft 21. Become. Therefore, these forces form a couple with the rotating shaft 21 interposed therebetween, and the force generating vibration is canceled out and does not exist. By this couple, the turning side to which the coil 23 is fixed turns in the direction indicated by the arrow R2 in accordance with the direction of the current I.

Next, a second embodiment, which is a combination of the fine movement drive section 4 and the coarse movement drive section 2 described above, will be described.
The actuators 2 and 3 in the stages will be described.

First, the two-stage actuator 2 shown in FIG. 6 will be described. The coarse drive section 5 has substantially the same drive configuration and operation as the actuator 1 described in the first embodiment. That is, the current I flowing through the coil 13 of the coarse driving unit 5 and the magnetic flux density B generated by the magnets 12a and 12b
The arm 15 rotates in the direction indicated by the arrow R1 around the rotating shaft 11 by the force of the interaction with the magnetic field, thereby positioning the magnetic head near a desired track on the disk at a high speed.

The fine movement drive unit 4 described above is provided at the end of the arm 15 of the coarse movement drive unit 5 to constitute the two-stage actuator 2. The magnets 22 a and 22 b of the fine movement drive unit 4 are fixed to the tip of the arm 15, and the fine movement drive unit 4 is screwed through a hinge spring 28.
And the like. When a current is applied to the coil 23, a couple is generated across the rotating shaft 21 by the action of the magnetic field generated by the magnets 22a and 22b, and the coil 23 rotates in the direction indicated by the arrow R2. The fine drive unit 4 has a small moment of inertia and can perform high-speed and high-precision position control. The combined operation with the coarse drive unit 5 enables high-speed and high-precision positioning of the magnetic head to a position far away. Will be able to do that.

Next, the two-stage actuator 3 shown in FIG. 7 will be described. The rotary actuator described in the conventional example is used as the coarse driving unit 6. Coil 40
Of the arm 1 around the rotation axis 11 due to interaction with a magnetic field by a magnet (not shown).
5 rotates in the direction indicated by arrow R1 to position the magnetic head near a desired track on the disk at a high speed.

The fine movement drive unit 4 described above is provided at the tip of the arm 15 of the coarse movement drive unit 6 to constitute the two-stage actuator 3. The magnets 22 a and 22 b of the fine movement drive unit 4 are fixed to the tip of the arm 15, and the fine movement drive unit 4 is screwed through a hinge spring 28.
And the like. When a current is applied to the coil 23, a couple is generated across the rotating shaft 21 by the action of the magnetic field generated by the magnets 22a and 22b, and the coil 23 rotates in the direction indicated by the arrow R2. The fine movement drive unit 4 has a small moment of inertia and can perform high-speed and high-precision position control. The combined operation with the coarse movement drive unit 6 enables high-speed and high-precision positioning of the magnetic head to a position far away. Will be able to do that.

Although the rotary actuator described in the conventional example is used as the coarse movement drive unit 6 of the actuator 3, the fine and accurate positioning of the magnetic head is performed by the fine movement drive unit 4. There is little possibility that vibration will occur, and this is not a problem in practical use.

According to the first and second embodiments described above, since the hinge spring made of a leaf spring-like member is used to attach the rotating portion, free rotation can be performed by utilizing its elastic deformation. In this case, the problem of delay in response due to backlash of the bearing and the problem of the return to the origin when the bearing is used is solved.
In addition to this, the moment of inertia of the rotating part can be reduced, the positioning control of the magnetic head can be performed with high speed and high accuracy, and the recording density of the magnetic disk can be increased.

Further, according to the magnetic head positioning apparatus of the second embodiment, the coarse movement drive unit is moved for a long distance from the inner peripheral side to the outer peripheral side of the disk, or about 3 to 5 μm corresponding to the conventional track jump. Used for relatively large movement of
On the other hand, since the fine movement drive unit is used for positioning the magnetic head with high precision, the positioning control of the magnetic head can be performed at higher speed and with higher precision, and the recording density of the magnetic disk can be further increased.

Furthermore, since the ability to trace a track is improved, it is possible to reduce the occurrence of errors during recording and reproduction of information, and to provide a highly reliable magnetic disk device having a high recording capacity.

The method for fixing the base plate to the arm is not limited to screwing, and other fixing means may be used.

The hinge spring is not limited to the above-mentioned shape, but may be any shape having the same function.

Also, a base plate, a suspension,
The hinge spring may be an integral member instead of a separate component.

Further, the actuator of the present invention may be sandwiched from both sides of the disc to record and reproduce on both sides of the disc.

Further, it is needless to say that the actuator of the present invention may be stacked in a plurality of stages and used for a magnetic disk device having an extremely large capacity.

[0046]

As is apparent from the above description, the present invention relates to a magnetic head positioning apparatus which enables high-speed and high-accuracy tracking control, track jump control, and the like in a magnetic disk with a high recording density. By using the magnetic head positioning device, it is possible to realize a magnetic disk device having a high recording capacity.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a first embodiment according to the present invention.

FIG. 2 is a diagram illustrating a configuration of a driving unit according to the first embodiment.

FIG. 3 is a perspective view showing an example of a structure of a hinge spring used in the present invention.

FIG. 4 is a view for explaining the operation of the hinge spring shown in FIG. 3;

FIG. 5 is a perspective view showing a configuration of a fine movement actuator used in a second embodiment according to the present invention.

FIG. 6 is a perspective view of an actuator according to a second embodiment.

FIG. 7 is a perspective view of an actuator according to a second embodiment.

FIG. 8 is a perspective view showing a configuration of a general magnetic disk drive.

FIG. 9 is a diagram for explaining the rotational force of the actuator of the magnetic disk device shown in FIG. 8;

FIG. 10 is a diagram for describing generation of vibration on a rotation axis of an actuator.

[Explanation of symbols]

1, 2, 3 ... actuator, 4 ... fine movement drive, 5,
6 ... Coarse movement drive unit, 11, 21, 41 ... Rotating shaft, 12
a, 22a, 12b, 22b, 39 ... magnet, 1
3, 23, 40 ... coil, 14, 24 ... base plate, 15, 37 ... arm, 16, 36 ... suspension, 17, 35 ... slider, 18, 28 ... hinge spring, 18a ... movable surface, 18b ... spring part, 18c ... Fixing surface, 18d: slit, 18e: hole, 25: screw, 30
… Magnetic disk device, 31… housing, 32… spindle motor, 33… disk, 34… rotary actuator,
38 ... Yoke

Claims (8)

[Claims] 1. A magnetic head positioning device in which a magnetic head for recording and reproducing information on an information recording medium is mounted on a rotating side, and the rotating side is mounted on a fixed side via a rotating shaft. A coil is disposed on one of the moving side and the fixed side so as to surround the rotation axis on the rotation side, and the other side is aligned with the opposite side of the coil with the rotation axis interposed therebetween. A magnetic head positioning device comprising a plurality of magnets for generating a couple around an axis. 2. A magnetic head positioning device, wherein a magnetic head for recording and reproducing information on an information recording medium is mounted on a rotating side, and the rotating side is mounted on a fixed side via a rotating shaft. A coil is disposed on one of the moving side and the fixed side so as to surround the rotation axis on the rotation side, and the other side is aligned with the opposite side of the coil with the rotation axis interposed therebetween. A magnetic head positioning apparatus, comprising: a plurality of magnets for generating couples about a shaft; and a leaf spring-like member used as a support means for rotatably supporting the rotating side to the fixed side. 3. A magnetic head positioning device in which a magnetic head for recording and reproducing information on an information recording medium is mounted on a rotating side, and the rotating side is mounted on a fixed side via a rotating shaft. The head positioning device includes a first-stage coarse rotation mechanism and a second-stage fine movement rotation mechanism equipped with a magnetic head. The second-stage rotation mechanism Is the second-stage rotating shaft for rotating the magnetic head to one of the rotating side of the second-stage rotating mechanism or the rotating side of the first-stage rotating mechanism. , And a plurality of magnets are provided on the other side so as to coincide with the opposite sides of the coil with respect to the second-stage rotation axis and generate couples around the rotation axis. And a supporting means for rotatably supporting the second stage rotating side to the first stage rotating side. Magnetic head positioning device which is characterized by using a spring-like member. 4. A magnetic head positioning device in which a magnetic head for recording and reproducing information on an information recording medium is mounted on a rotating side and the rotating side is mounted on a fixed side via a rotating shaft. The head positioning device includes a first-stage coarse rotation mechanism and a second-stage fine movement rotation mechanism equipped with a magnetic head. The second-stage rotation mechanism Is the second-stage rotating shaft for rotating the magnetic head to one of the rotating side of the second-stage rotating mechanism or the rotating side of the first-stage rotating mechanism. And a plurality of magnets are provided on the other side so as to coincide with the opposite side of the coil with respect to the second-stage rotation axis and generate a couple around the rotation axis. Further, the first-stage rotating mechanism may be either a rotating side or a fixed side of the first-stage rotating mechanism. On one side, a coil is provided so as to surround the first-stage rotation axis for rotating the magnetic head, and on the other side, an opposite side of the coil with the first-stage rotation axis interposed therebetween. And a plurality of magnets for generating couples around the rotation axis, and as a support means for rotatably supporting the second stage rotation side to the first stage rotation side. A magnetic head positioning device using a leaf spring-like member. 5. A magnetic disk drive comprising the magnetic head positioning device according to claim 1. 6. A magnetic disk drive comprising the magnetic head positioning device according to claim 2. 7. A magnetic disk drive comprising the magnetic head positioning device according to claim 3. 8. A magnetic disk drive comprising the magnetic head positioning device according to claim 4.