JP2002123919A - Head carriage mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a head carriage mechanism capable of reducing the measuring error of a disk by reducing a positioning error due to yawing. SOLUTION: This mechanism is provided with a moving base, and a head support arm including a magnetic head assembly one end of which is attached to the moving base, and having a magnetic head at the other end. In this case, the moving axial center direction of the moving base substantially passes through the rotational center of a disk, and the head support arm has a shape for positioning a magnetic head in the moving axial center direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head carriage mechanism, and more particularly to a magnetic disk tester or a magnetic head tester using a high-density recording magnetic head using a low-flying thin-film head to reduce a positioning error due to yawing. Thus, the present invention relates to a head carriage mechanism that can reduce measurement errors of a tester and is particularly effective for measuring off-track characteristics of an MR head.

[0002]

2. Description of the Related Art In a conventional magnetic disk tester or magnetic head tester (hereinafter referred to as a "tester"), a magnetic head for accessing a hard magnetic disk is supported on a moving table of a head carriage by a head supporting arm on one side via a supporting spring. That is, the magnetic disk is loaded in a so-called overhang state to access the magnetic disk. In particular, data is recorded at a very high density on a disk that reads / writes using an MR head, a GMR head, and a TMR head (a tunnel MR head) (hereinafter, these heads are represented by MR heads). The number of tracks is 1000-2000 or more,
A high-speed and high-precision seek (access) of each magnetic head is performed on each track. The MR head is integrated with an inductive head for writing and is integrated as one magnetic head, so that an offset occurs in the MR head with respect to a writing track of the inductive head. Correction is required. Therefore, in a magnetic head using an MR head, the off-track characteristic of the MR head is measured, and the offset amount of the MR head with respect to the inductive head is measured. However, this requires a positional reproducibility on the order of nm at the head gap position. Is done.

[0003]

When a magnetic head accesses a magnetic disk, a head carriage (moving table) is used.
When the carriage is stopped, the magnetic head supported in an overhang state via the support spring when the carriage is stopped causes yawing (vibration shaking the head left and right), causing a head gap displacement in the track width direction. Causes a measurement error. FIG. 2 is a schematic diagram of a head carriage mechanism in a conventional tester. 10 is a magnetic disk 2
0 is a head carriage mechanism for loading the magnetic head to a position on a track on the magnetic disk 20 by loading the magnetic head on the magnetic disk 20. Numeral 11 denotes the movable table, numeral 12 denotes a support on the bearing side, numeral 13 denotes a bearing, numeral 14 denotes a head support arm, numeral 15 denotes a magnetic head assembly, numeral 16 denotes a piezo actuator, and numeral 17 denotes a return spring. The magnetic head assembly 15 includes a head support spring 15a and a magnetic head 15.
b etc.

The head carriage mechanism 10 drives the piezo actuator 16 in accordance with the positioning target position to drive the moving table 11 forward, and the yaw at the time of head positioning causes a vibration shown by a dotted line. D
Is the positioning error in the track width direction at this time. The retreat is performed by the return spring 17, and there is a similar yawing. The head support arm 14 is usually formed of a straight, plate-like aluminum plate, and the axis of the moving table 11 in the moving direction is set to coincide with the rotation center O of the magnetic disk 20. Due to such a relationship, the gap position of the magnetic head 15b is not on the moving axis Ao of the moving table 11, but is usually located on the left side as shown in the figure. Therefore, the error of the movement of the movable base 11 due to the yawing and the error of the head gap position appear as an error in the track width direction as it is. Since the measurement accuracy of the tester greatly depends on the positioning error D of the head carriage mechanism in the disk track width direction (radial direction of the disk), reducing this error D is indispensable for improving the performance of the tester. As the recording density of the magnetic head increases, an error D due to yawing becomes a problem, and this limits the improvement of the measurement accuracy particularly in the off-track measurement of the MR head. For example, even if the same magnetic head is repeatedly measured about 30 times, the offset amount has no reproducibility, and the measured value varies, and high-precision measurement on the order of nm is impossible. The purpose of this invention is
In order to solve such problems of the prior art,
An object of the present invention is to provide a head carriage mechanism capable of reducing a measurement error of a tester by reducing a positioning error due to yawing.

[0005]

A feature of the head carriage mechanism of the present invention for achieving the above object is that a head carriage for loading a magnetic head on a magnetic disk and positioning the magnetic head on a track on the magnetic disk. A moving table, and a head support arm having a magnetic head assembly having one end attached to the moving table and a magnetic head at the other end. The moving axis of the moving table is aligned with the rotation center of the magnetic disk. And the head support arm has a shape for positioning the magnetic head in the direction of the axis of movement.

[0006]

As described above, according to the present invention, the head support arm has a shape for positioning the magnetic head on a line connecting the rotation center of the magnetic disk and the moving axis of the moving table. Therefore, even if yawing occurs at the time of positioning, the amount of displacement of the head gap in the width direction of the trunk can be reduced. As a result, the measurement error of the tester can be reduced by reducing the positioning error due to the yawing.

[0007]

FIG. 1 is a block diagram showing an embodiment to which a head carriage mechanism according to the present invention is applied. The same components as those in FIG. 2 are denoted by the same reference numerals. As shown in FIG.
The head carriage mechanism 1 is a head support arm 1 shown in FIG.
In place of the head support arm 4, the head support arm 2 is bent in a crank shape. Other components are the same as those in FIG. The head support arm 2 has a front end 3 to which the magnetic head assembly 15 is fixed, the magnetic head 15 b, the moving head axis Ao of the moving table 11 and the magnetic disk 20.
In particular, the head gap is substantially equal to the magnetic disk 20.
Is bent so that it is offset by the distance L between the distal end 3 of the head support arm 2 and the moving axis Ao so as to be located on the moving axis Ao passing through the center O of the head. This allows
The error amount D1 due to yawing generated when driving and positioning the piezo actuator 16 satisfies D1 <D, which is smaller than in the case of FIG. The reason is that the distance from the center O ′ of the movable base 11 to the magnetic head 15b is different from that in FIG.
This is because the yaw angle occurs from the moving axis Ao because the yaw occurs with reference to the center O ′.

For example, if yawing occurs for one second, the amount of overhang from the center of the moving table 11 is 100 m.
m, when the head skew angle is zero degree at a position of a radius of 20 mm of the magnetic disk 20, the positioning error in the width direction is reduced to about 1/1000 in comparison with the embodiment of FIG. 1 and the conventional technique of FIG. Can be reduced. As a result, the measurement accuracy in the off-track measurement of the MR head is improved, and even if the same magnetic head is measured about 30 times, n
Measurement can be performed with an accuracy on the order of m.

As described above, in the embodiment, the head supporting arm has a crank shape, but this shape is not limited to the crank shape.

[0010]

As described above, according to the present invention, the head support arm has a shape for positioning the magnetic head on a line connecting the center of rotation of the magnetic disk and the center of movement of the moving table. In addition, even if yawing occurs during positioning, the amount of displacement of the head gap in the width direction of the trunk can be reduced. As a result, the measurement error of the tester can be reduced by reducing the positioning error due to the yawing.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment to which a head carriage mechanism of the present invention is applied.

FIG. 2 is a schematic diagram of a head carriage mechanism in a conventional tester.

[Explanation of symbols]

1, 10: Head carriage mechanism, 2, 14: Head support arm, 11: Moving table, 12: Bearing-side support, 1
3 ... Bearing, 15 ... Magnetic head assembly, 15
a: head support spring, 15b: magnetic head, 16: piezo actuator, 17: return spring, 20: magnetic disk.

Claims (2)

[Claims] 1. A head carriage mechanism for loading a magnetic head onto a magnetic disk and positioning the magnetic head on a track on the magnetic disk, comprising: a moving table; one end attached to the moving table and the magnetic head A magnetic head assembly having a fixed head support arm, wherein the direction of the axis of movement of the moving table substantially passes through the center of rotation of the magnetic disk, and the direction of the axis of the head support arm is set in the direction of the axis of the movement axis. A head carriage mechanism having a shape for positioning the magnetic head. 2. The head carriage mechanism according to claim 1, wherein said head support arm has a crank shape and is incorporated in a magnetic disk head tester or a magnetic disk tester.