JP2589625B2 - Hard disk and magnetic head testing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test of a hard disk or a magnetic head used in an actual hard disk drive (hereinafter referred to as an HDD) having a swing arm type magnetic head positioning mechanism. In particular, the present invention relates to a tester called "spin stand" used for such a tester, and more particularly to a tester that enables a test equivalent to a real HDD.

[0002]

2. Description of the Related Art A hard disk and a magnetic head testing machine are provided with a hard disk rotation spindle and a magnetic head positioning mechanism, as in the actual machine. Many of the magnetic head positioning mechanisms of the conventional testing machine are those of the actual machine. Unlike the (swing arm type), the magnetic head is positioned by a direct-acting stage. This is because versatility is considered.

[0003]

However, using a tester for positioning a magnetic head by such a direct-acting stage, a disk or a magnetic head for an actual HDD having a swing arm type magnetic head positioning mechanism is used. When the test is performed, the azimuth angle of the magnetic head changes for each track in the actual machine, whereas the azimuth angle is always constant in the test machine, so that the test under the same conditions as the actual machine cannot be performed.

A change in the azimuth angle of the magnetic head means a change in the slider angle. When the slider angle changes, the flying height of the magnetic head with respect to the disk changes. Further, the change in the flying height of the magnetic head is greatly related to the strength of the signal level for recording and reproducing on the disk. As described above, the conventional simple linear motion stage test machine cannot perform an equivalent test with an actual machine having a swing arm type magnetic head positioning mechanism.

[0005] One method of performing an equivalent test with an actual machine having a swing arm type magnetic head positioning mechanism is to use a test machine having exactly the same mechanism as the actual machine. However, since the arm radius, the position of the pivot axis, and the like are limited, it is difficult to cope with many types, and there is a disadvantage that the versatility required for the testing machine is greatly sacrificed.

Another method is a method of calculating coordinates at which a track position and an azimuth angle are equal to those of an actual machine having a swing arm type positioning mechanism using a stage orthogonal to two axes, and positioning the magnetic head at that point. . However, this method has no problem in theory as an azimuth angle equivalent tester, but since the magnetic head does not move on a straight line, the read / write timing for the index signal changes for each track, and data processing becomes complicated. There is a disadvantage. Also, care must be taken not to interfere with the spindle shaft at the innermost diameter.

In view of such circumstances, the present invention has
An object of the present invention is to provide a simple and versatile hard disk and magnetic head tester that enables a test equivalent to DD.

[0008]

Means for Solving the Problems] Therefore, the present invention is mounted as a magnetic head positioning mechanism, and a linear motion mechanism for linearly moving in the radial direction of the hard magnetic head through the linear motion member, to the linear motion member Slidable arc motion
It has a member, provided with azimuth angle adjusting mechanism for adjusting the azimuth angle by rotating the magnetic head on the linear motion member, the magnetic
The head is mounted directly on the sliding member to secure the magnetic head.
The center of the light / write gap at the center of the arc
On the other hand, a control device that calculates an azimuth angle corresponding to a track position in the actual HDD and controls the azimuth angle adjustment mechanism so as to obtain the same azimuth angle as in the actual HDD according to the track position changed by the linear motion mechanism. Are provided to configure a tester for a hard disk and a magnetic head.

[0009]

In the above configuration, the magnetic head is moved linearly in the radial direction of the hard disk by the linear motion mechanism,
The azimuth angle is adjusted by rotating the magnetic head at each track position. At the time of adjustment, the azimuth angle corresponding to the track position in the actual HDD is calculated. This can be obtained, for example, by inputting in advance the turning radius of the swing arm and the center-to-center distance between the disk and the arm as parameters, and giving the radius of each track of the disk as a variable. Then, based on this, the azimuth angle adjusting mechanism is controlled in the test machine in accordance with the track position changed by the linear motion mechanism, and the same azimuth angle as in the actual HDD is obtained.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show one embodiment of a tester according to the present invention. The testing machine is provided with a spindle 2 for mounting and rotating the hard disk 1.

Further, the tester is provided with a positioning mechanism for the magnetic head 3, which will be described. A translation stage 5 as a translation member is slidably guided in the left-right direction in FIG. A ball screw 6 extending in the guide direction is rotatably supported on the base 4, and the ball screw 6 is screwed to the translation stage 5. One end of the ball screw 6 is connected to an output shaft of a pulse motor 7 that can rotate forward and reverse. Therefore, by rotating the ball screw 6 by the pulse motor 7, the translation stage 5 can be moved in the left-right direction in FIG. 1 and includes the base 4, the translation stage 5, the ball screw 6 and the pulse motor 7. A linear motion mechanism is configured.

A support member 8 is fixed to the front surface of the translation stage 5. A concave arc surface 8a is formed on the front surface of the support member 8, and a ridge 8b extends along the arc surface 8a.
(See FIG. 2). A notch 8c (see FIG. 2) extending in the left-right direction is formed at the center of the ridge 8b. The support member 8 has the concave arc surface 8.
a and the protruding arc surface 9a and the dovetail groove 9 corresponding to the ridge 8b
A gonio stage 9 as a sliding member having b on the rear surface is slidably mounted.

The gonio stage 9 has a dovetail groove 9b.
Worm wheel 10 protruding from the center of
Are formed. A worm gear 11 is rotatably supported inside the notch 8 c of the support member 8 and meshes with the worm wheel 10. One end of the worm gear 11 is connected via a coupling 12 to an output shaft of a pulse motor 13 which can rotate forward and reverse. Therefore, by rotating the worm gear 11 by the pulse motor 13, the gonio stage 9 can be moved in an arc.

A magnetic head mounting portion 14 is provided on the gonio stage 9 and the read / write / write
The magnetic head 3 is mounted in an assembled state such that the center of the gap is located at the center of the arc. Accordingly, an azimuth angle adjustment mechanism is configured to include the support member 8, the gonio stage 9, the worm wheel 10, the worm gear 11, the coupling 12, and the pulse motor 13.

FIG. 3 shows an example of the magnetic head 3. In this example, the suspension 31 and the slider 32 are mounted in a transversal type. Reference numeral 33 denotes a ferrite core, reference numeral 34 denotes a gap, and reference numeral 35 denotes a floating surface taper portion. Here, the pulse motor 7 of the direct acting mechanism and the pulse motor 13 of the azimuth angle adjusting mechanism are controlled by a control device 15 built in the microcomputer.

The control device 15 calculates an azimuth angle corresponding to a track position in the actual HDD and outputs the pulse motor 7
The magnetic head 3 is moved by the pulse motor 13 through the gonio stage 9 so that the same azimuth angle as in the actual HDD is obtained in accordance with the track position changed by the movement of the magnetic head 3 through the linear motion stage 5 by the motor. Rotate around the center of the gap to adjust the azimuth angle.

Next, a method of calculating the azimuth angle according to the track position in the actual HDD will be described. FIG. 4 shows an actual HDD having a general swing arm type magnetic head positioning mechanism. In the figure, 41 is a hard disk, 42 is a spindle, 43 is a magnetic head, 44 is an arm, and 45 is an arm turning axis.

FIG. 5 shows how the azimuth angle changes as the track position changes. In the figure, reference numeral 51 denotes a track, 52 denotes a turning axis, 53 denotes a magnetic head point, and 54 denotes a magnetic head locus. When the track normal and the gap of the magnetic head coincide, the azimuth angle is zero, and FIG. 5 shows that the azimuth angle is θ.

Here, the following relational expression is established from FIG. I ² = R ² + r ² -2R cosΨ (1) θ = 90 ° -Ψ (2) where I is the distance between the center of the disk and the arm, R is the turning radius of the arm, and r is The track radius of the disk, Ψ is the included angle between the track normal and the arm, and θ is the azimuth angle.

The following equations are derived from the equations (1) and (2). θ = 90 ° −cos ⁻¹ ((R ² + r ² −I ² ) / 2Rr) (3) Accordingly, it is possible to calculate the azimuth angle θ of the actual machine in each track using the equation (3). it can. That is, the turning radius R of the arm and the center distance I between the disk and the arm are input in advance as parameters, and the azimuth angle θ can be calculated using the track radius r of the disk as a variable.

Therefore, the control device 15 changes the value of r in accordance with the equation (3) according to the track position which is changed by the movement of the magnetic head 3 via the linear motion stage 5 by the pulse motor 7, The azimuth angle θ in the actual machine is determined, and based on this, the magnetic head 3 is rotated around the center of the gap by the pulse motor 13 via the gonio stage 9 and adjusted to the same azimuth angle θ as in the actual machine.

Assuming that the azimuth angles with respect to the track radii r ₁ and r ₂ of a certain actual machine are θ ₁ and θ ₂ , the conventional test machine uses a biaxial orthogonal stage as shown in FIG. Position. On the other hand, in the method according to the present invention, the magnetic head moves on a straight line as shown in FIG.
There is no need to correct the timing for the index signal.

The tester can be used not only for testing the hard disk and the magnetic head itself but also for a flying height measuring device.

[0024]

As described above, according to the present invention, a test of a hard disk and a magnetic head used in an actual machine having a swing arm type magnetic head positioning mechanism, which is becoming the mainstream in small HDDs at present, is a test equivalent to the actual machine. On the other hand, the tester can be simply and compactly assembled, which is effective in reducing space and cost.

[Brief description of the drawings]

FIG. 1 is a plan view of a main part of a testing machine showing an embodiment of the present invention.

FIG. 2 is a side sectional view of a gonio stage part of FIG. 1;

FIG. 3 shows an example of a magnetic head.

FIG. 4 is a schematic view of a swing arm type magnetic head positioning mechanism.

FIG. 5 is a diagram showing a state in which an azimuth angle changes depending on a track position.

FIG. 6 is a diagram showing an example in which an azimuth angle is adjusted by a two-axis orthogonal stage.

FIG. 7 is a diagram showing an example of performing azimuth angle adjustment according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hard disk 2 Spindle 3 Magnetic head 4 Base 5 Linear stage 6 Ball screw 7 Pulse motor 8 Support member 9 Goniometer stage 10 Worm wheel 11 Worm gear 13 Pulse motor 14 Magnetic head mounting part 15 Control device

Claims (1)

(57) [Claims] 1. A tester, comprising: a hard disk rotation spindle; and a magnetic head positioning mechanism, for testing at least one of a hard disk and a magnetic head used in an actual hard disk drive having a swing arm type magnetic head positioning mechanism. As the magnetic head positioning mechanism, a linear motion mechanism that linearly moves the magnetic head in the radial direction of the hard disk via a linear motion member, and an arc motion attached to the linear motion member.
Has a sliding member that, setting the azimuth angle adjusting mechanism for adjusting the azimuth angle by rotating the magnetic head on the linear motion member
The magnetic head is directly attached to the sliding member,
The center of the read / write gap of the
While being positioned at the center, the azimuth angle adjusting mechanism is calculated so as to obtain the same azimuth angle as in the real hard disk drive according to the track position changed by the linear motion mechanism while calculating the azimuth angle according to the track position in the real hard disk drive. A hard disk and a magnetic head testing machine, comprising a control device for controlling the magnetic head.