JPH11203637A - Device for inspecting contact - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence of vibration of an arm on the detection of the contact between a slider and a disk, and to make the evaluating system hardly influenced by the mounting of an AE(acoustic elastic wave) sensor, which is a vibration detecting element, and further to attain the highly accurate evaluation of the influence given to the disk side by the contact. SOLUTION: The device is at least provided with a spindle 2 for rotating the disk while holding it, the slider 4 mounted with a head for recording to and/or reproducing from the disk 1, the arm 5 moved in the prescribed direction in the state of supporting the slider 4, the AE sensor 101 for detecting the contact between the slider 4 and disk 1, and a spring 11 and a brush 12 as a signal transmitting means for transmitting an output signal of the AE sensor 101. The AE sensor 101 is mounted on the disk 1 or the spindle 2, and the contact between the slider 4 and the disk 1 is inspected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slider and disk contact inspection apparatus used for evaluating mechanical characteristics and tribological characteristics of a disk drive slider and disk.

[0002]

2. Description of the Related Art For example, in a magnetic disk device for magnetically recording and / or reproducing information as a disk device, a slider on which a magnetic head is mounted is floated at substantially constant intervals on a recording / reproducing surface of a magnetic disk. Recording and reproducing information.

In the development and manufacture of such a magnetic disk drive, in order to guarantee the mechanical characteristics and tribological characteristics of the slider and the magnetic disk,
Various inspection devices are used. A contact inspection device between a slider and a magnetic disk is one of them.

As a device for inspecting the contact between a slider and a magnetic disk, a technique described in Japanese Patent Application Laid-Open No. Hei 8-297816 is known. FIG. 5 shows an example of a conventional device for inspecting contact between a slider and a magnetic disk. A magnetic disk 1 as a recording medium, a spindle 2 for holding and rotating the magnetic disk 1, a spindle drive circuit 3 as a spindle driving means for driving the spindle 2, and a magnetic head for recording and reproducing on the magnetic disk 1 (not shown) 4), and an arm 5 supporting the slider 4
A voice coil motor 6 as an actuator for moving the arm 5 and moving the slider 4 attached to the arm 5 in the radial direction of the magnetic disk 1, an actuator driving circuit 7 as driving means for the voice coil motor 6, An AE (acoustic elastic wave) sensor 100 as a micro-vibration detecting element mounted on the arm 5 and an AE sensor 1
00, a high-band amplifier 8 as a signal amplifying means for amplifying the output signal, a filter 9 for extracting a frequency component necessary for contact inspection from the output signal of the high-band amplifier 8, and a display for displaying the output signal of the filter 9. And an oscilloscope 10 as a means.

The operation will be described below. The magnetic disk 1 is rotated at a high speed, for example, at 5,400 rpm by the spindle 2. The slider 4 has an air bearing surface on the surface facing the recording / reproducing surface of the magnetic disk 1.
Float at substantially constant intervals. Voice coil motor 6
Moves the slider 5 in the radial direction of the magnetic disk 1 by moving the arm 5. As described above, the slider 4 normally floats with respect to the magnetic disk 1. That is, the slider 4 and the magnetic disk 1 are in a non-contact state. However, the slider 4 often comes into contact with the magnetic disk 1 due to the start and stop of the rotation of the magnetic disk 1, the adhesion of dust to the slider 4, and the shape defect of the slider 4 and the magnetic disk 1.

In the conventional example shown in FIG. 5, an AE sensor 100 as a micro vibration detecting element is mounted on an arm 5, and an AE generated by contact between the slider 4 and the magnetic disk 1, that is, an acoustic elastic wave is detected. I do. The detected output signal from the AE sensor 100 is amplified by the high-band amplifier 8 to a level that can be observed. Further, the noise component is removed by the filter 9 and the oscilloscope 1
Observed at 0. AE observed with oscilloscope 10
From the waveform of the output signal of the sensor 100, the strength of the contact, the duration of the contact, and the like can be evaluated.

[0007]

In the above-described contact inspection apparatus, the AE sensor 100 is mounted on the arm 5, and therefore, the AE sensor 100 is generated near the contact point due to the contact between the slider 4 and the magnetic disk 1. In addition to the AE signal, the vibration of the arm 5 is also superimposed and detected by the AE sensor 100. Therefore, the actual AE signal and arm 5
It was impossible to separate the signal from the signal due to the vibration of the sample, and it was difficult to improve the accuracy of the measurement. Further, by mounting the AE sensor 100 on the arm 5, the inertia of the arm 5 changes, and a difference occurs between the AE sensor 100 and an actual system in which the AE sensor 100 is not mounted. Further, the AE sensor 10
Since 0 is mounted on the slider 4 side, it is difficult to evaluate the influence of the contact on the magnetic disk 1 side with high accuracy.

SUMMARY OF THE INVENTION Accordingly, the problem to be solved by the present invention is to reduce the influence of the vibration of the arm on the detection of the contact between the slider and the magnetic disk, and to affect the system to be evaluated by mounting the micro vibration detecting element. Not to be
It is another object of the present invention to be able to evaluate the influence on the magnetic disk side due to contact with high accuracy.

[0009]

SUMMARY OF THE INVENTION The present invention provides a holding mechanism for holding and rotating a disk, a slider on which a head for recording and / or reproducing data on and from the disk is mounted, and a slider supporting the slider in a predetermined direction. At least an arm to be moved, a vibration detecting element for detecting contact between the slider and the disk, and signal transmission means for transmitting an output signal of the vibration detecting element. In addition, the vibration detection element is mounted on the disk, and as a contact inspection apparatus, it is not necessary to mount a vibration detection element on both arms, and therefore, the vibration of both arms is reduced. The influence on the contact detection between the sliders and the disks and the influence on the system to be evaluated by the vibration detecting element are reduced. It is possible to detect the contact with the disk side to solve the above problem by which enables to evaluate the effect of the disk side is subjected to high precision by contact.

[0010]

According to the first aspect of the present invention, there is provided a holding mechanism for holding and rotating a disk, a slider having a head for recording and / or reproducing data on and from the disk, and a state in which the slider is supported. An arm moved in a predetermined direction, a vibration detecting element for detecting contact between the slider and the disk, and signal transmitting means for transmitting an output signal of the vibration detecting element. In addition to inspecting the contact with the disk, the vibration detecting element is mounted on the disk, so that it is not necessary to mount the vibration detecting element on the arm side. The influence on detection and the influence on the system to be evaluated by the vibration detection element are reduced. Further, since the contact can be detected on the disk side, it is possible to evaluate with high accuracy the influence on the disk side due to the contact.

According to a second aspect of the present invention, there is provided a holding mechanism for holding and rotating a disk, a slider having a magnetic head for performing recording and / or reproduction on the disk,
An arm that is moved in a predetermined direction while supporting the slider, a vibration detecting element that detects a contact between the slider and the disk, and a signal transmitting unit that transmits an output signal of the vibration detecting element. By inspecting the contact between the slider and the disk and mounting the vibration detecting element on the holding mechanism, the same effect as in the first embodiment can be obtained.

The invention according to claim 4 is characterized in that the signal transmission means is fixed to the holding mechanism and rotates with the rotation of the holding mechanism, and the fixed body rotates with the rotation of the holding mechanism. Since the output signal of the vibration detection element is transmitted through the contact between the rotating conductor and the contact conductor, the signal from the vibration detection element can be transmitted reliably.

According to a sixth aspect of the present invention, the signal transmitting means is fixed to the holding mechanism, rotates with the rotation of the holding mechanism, and transmits a signal in the air. A signal receiver that receives the converted signal, and transmits the output signal of the vibration detection element via non-contact transmission and reception between the signal transmitter and the signal receiver. Disappears,
The contact detection accuracy is improved.

According to the present invention, since the vibration detecting element is an AE sensor, it can detect minute vibration with high sensitivity.

According to the ninth aspect of the present invention, since a fluid bearing is used for the bearing portion of the holding mechanism, no noise is generated due to the bearing because the fluid bearing is not in contact, and the contact detection accuracy is improved.

According to a tenth aspect of the present invention, there is provided a holding mechanism for holding and rotating a disk, a slider on which a head for recording and / or reproducing data on and from the disk is mounted, and a slider supporting the slider in a predetermined direction. An arm to be moved, a first vibration detection element for detecting contact between the slider and the disk, a second vibration detection element mounted on the disk or the holding mechanism, and a first vibration detection element. First signal amplification means for amplifying the output signal;
First effective value calculating means for calculating an effective value from the signal amplified by the first signal amplifying means; and determining whether or not the output of the first effective value calculating means has exceeded a predetermined value. A signal processing circuit for outputting an output signal of the second vibration detection element, a second signal amplifying means for amplifying the output signal extracted by the signal transmission means, Second effective value calculating means for calculating an effective value from the signal amplified by the second signal amplifying means;
A second signal processing circuit for judging whether or not the output of the effective value calculation means has exceeded a predetermined value and outputting the result; and detecting the contact between the slider and the disk from the output results of the two signal processing circuits. Since the configuration is provided with the contact determination means for determining, it is possible to obtain an effect that it is possible to detect the contact between the slider and the disk with higher accuracy than before.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1) FIG. 1 shows an embodiment according to the present invention. In FIG. 1, portions corresponding to those in FIG. 5 are denoted by the same reference numerals, and detailed description of the portions corresponding to the same reference numerals is omitted. In FIG. 1, 1 is a magnetic disk as a recording medium disk, 2 is a spindle as an example of a holding mechanism for holding and rotating the magnetic disk 1, 3 is a spindle driving means for driving the spindle, and 4 is a magnetic disk drive. A slider on which a magnetic head for performing recording and / or reproduction is mounted;
, 6 is a voice coil motor as an actuator for moving the scribe 4 in the radial direction of the magnetic disk 1, 7 is an actuator drive circuit as a driving means of the voice coil motor, and 8 is an output signal of the AW sensor 101. A high-bandwidth amplifier as a signal amplifying means,
Reference numeral 9 denotes a filter for extracting a frequency component necessary for contact inspection from an output signal of the high-band amplifier 8, 10 denotes an oscilloscope as display means for displaying an output signal of the filter, 101
Denotes an AE sensor as a vibration detecting element mounted on the arm 5.

Reference numeral 11 denotes a slip ring as an example of a rotating conductor, and reference numeral 12 denotes a brush as an example of a contact conductor.

More specifically, the magnetic disk 1
Is fixed to the spindle 2 by, for example, screwing. A DC servomotor is used as a motor for the spindle 2, and the magnetic disk 1 can be driven at a constant rotation speed from 0 rpm to 10,000 rpm or more. A fluid bearing is used for a bearing portion of the spindle 2. A slider 4 on which a magnetic head (not shown) is mounted is attached to the arm 5. Slider 4
An air bearing surface is formed on the surface of the magnetic disk 1 facing the recording / reproducing surface by machining or etching. The air bearing surface of the slider 4 is, for example, 30 Nm by the arm 5 on the recording / reproducing surface of the magnetic disk 1.
It is pressed with a constant load. Slider 4
As the magnetic disk 1 rotates, pressure is generated on the air bearing surface and the magnetic disk 1 flies above the magnetic disk 1.
The arm 5 is attached to a voice coil motor 6 as an actuator.
Rotate around the axis. Thus, the slider 4 attached to the arm 5 moves in the radial direction of the magnetic disk 1. On the recording / reproducing surface of the magnetic disk 1, an AE sensor 101 as a micro vibration detecting element is mounted. Here, when the slider 4 comes into contact with the magnetic disk 1 for some reason, AE, that is, an acoustic elastic wave is generated at the contact point. The AE sensor 101 converts the AE, that is, the acoustic elastic wave into an electric signal.

The output signal of the AE sensor 101 is guided to a slip ring 11 and a brush 12 as signal transmission means and taken out. The output signal of the AE sensor 101 taken out is amplified by the high-band amplifier 8 to a detectable level. Amplified AE sensor 10
From the output signal from 1, only the frequency to be observed by the filter 9 is extracted. And the AE that passed through filter 9
An output signal from the sensor 101 is observed by an oscilloscope 10 as a display. From the signal waveform observed by the oscilloscope 10, the strength of contact between the slider 4 and the magnetic disk 1, the duration of contact, and the like can be known.
Here, the case where the AE sensor is used as the minute vibration detecting element has been described, but any element that can detect minute vibration due to the contact between the slider 4 and the magnetic disk 1 may be used, and an acceleration sensor, a strain gauge, or the like may be used. . A
Although the case where only one E sensor is used has been described, a plurality of AE sensors may be mounted on the magnetic disk 1. In the present embodiment, an example in which a fluid bearing is used as the bearing portion of the spindle 2 has been described. However, when a contact-type bearing such as a ball bearing is used, the vibration is also reduced by the AE sensor 1.
01, and the S / N of contact detection between the slider 4 and the magnetic disk 1 is deteriorated. Therefore, the bearing is not limited to the fluid bearing as long as the S / N can be sufficiently secured.

As described above, in the first embodiment, the AE of the AE sensor 101 generated in the vicinity of the contact point between the scribe 4 and the magnetic disk 1 due to the contact between the scribe 4 and the magnetic disk 1.
The signal is guided to the slip ring 11 and the brush 12 and is taken out. In this case, since the output signal of the AE sensor 101 does not include a signal component due to the influence of the vibration of the arm 5, the influence of the AE sensor 101 on the detection of the contact between the scribe 4 and the magnetic disk 1 is reduced. The effect on the magnetic disk 1 due to the contact can be evaluated with high accuracy.

(Embodiment 2) FIG. 2 shows Embodiment 2 according to the present invention. A description of the same configuration as in the first embodiment will be omitted. In the first embodiment, the AE sensor 101, which is a micro vibration detecting element, is mounted on the magnetic disk 1. In the second embodiment, the AE sensor 102, which is a micro vibration detecting element, is mounted on the spindle 2 which is a holding mechanism. ing. With such a configuration, even when the magnetic disk 1 is replaced, the above-described evaluation can be performed with high accuracy without removing the AE sensor 102, and work efficiency can be improved. Become. In addition, there is no fear of damaging the magnetic disk 1 by attaching the AE sensor 102 to the magnetic disk 1.

(Third Embodiment) FIG. 3 shows a third embodiment according to the present invention. A description of the same configuration as in the first embodiment will be omitted. In the first embodiment, the output signal from the AE sensor 101 mounted on the magnetic disk 1 is
Although the slip ring 11 and the brush 12 are used as signal transmitting means and are taken out to the outside, in the third embodiment, the AE sensor 1 mounted on the magnetic disk 1 is used.
A signal transmitting means 03, which is capable of transmitting signals in a non-contact manner, is fixed to the spindle 2 and rotates together with the rotating operation of the spindle 2 and transmits a signal in the air; A fixed transformer 13b is used as an example of a signal receiver that receives a signal. When the slip ring and the brush are used, the AE sensor detects not only the signal due to the contact between the slider 4 and the magnetic disk 1 but also the vibration due to the sliding contact between the slip ring and the brush. However, there is a problem in that the metal is deteriorated. Embodiment 3
As described above, by using the rotary transformer 13a and the fixed transformer 13b facing the rotary transformer 13a as signal transmission means, the output signal of the AE sensor 103 can be transmitted in a non-contact manner. S / N of contact detection is improved.

(Embodiment 4) FIG. 4 shows Embodiment 4 according to the present invention. A description of the same configuration as in the first embodiment will be omitted. An AE sensor 105 serving as a first minute vibration detecting element is mounted on the arm 5. When the slider 4 comes into contact with the magnetic disk 1 for some reason, AE, that is, an acoustic elastic wave is generated at the contact point. The AE sensor 105 converts the AE, that is, the acoustic elastic wave into an electric signal. The output signal of the AE sensor 105 is amplified by the high band amplifier 13 to a detectable level. The amplified output signal from the AE sensor 105 is guided to an effective value calculation circuit 14 which is a first effective value calculation means. When the signal from the AE sensor 105 calculated by the first effective signal processing circuit 14 exceeds a predetermined value by the first signal processing circuit 14, the output signal from the effective value calculating circuit 14 is HI (5V). ) Is output. Otherwise, LOW (0
V).

An AE sensor 104 serving as a second minute vibration detecting element is mounted on the magnetic disk 1. A
The output signal of the E sensor 104 is guided to the slip ring 11 and the brush 12 as signal transmission means and taken out. The output signal of the AE sensor 104 taken out is amplified by the high-band amplifier 16 to a detectable level. The amplified output signal from the AE sensor 104 is guided to an effective value calculation circuit 17 which is a second effective value calculation means. The output signal from the effective value calculation circuit 17 outputs HI (5 V) at the TTL level when the effective value signal calculated by the effective value calculation circuit 17 exceeds a certain value by the second signal processing circuit 18. It is supposed to. Otherwise, it is LOW (0 V). The output signal of the signal processing circuit 15 and the output signal of the signal processing circuit 18 are guided to a contact determination circuit 19 serving as contact determination means, and the logical product of the respective output signals is obtained. Is determined to have come into contact with. According to the fourth embodiment, since the contact is determined on both the slider 4 side and the disk 1 side, the accuracy of the contact inspection is improved.

[0027]

As described above, according to the present invention, by mounting the vibration detecting element on the disk or the holding mechanism, the influence of the vibration of the arm on the detection of the contact between the slider and the disk and the system for evaluating the vibration detecting element are evaluated. The effect on the disk side is reduced, and the contact can be detected on the disk side, which makes it possible to evaluate the effect of the contact on the disk side with high accuracy.Furthermore, the vibration detection on both the slider side and the disk side The effect that the detection accuracy is improved by mounting the element and detecting the contact with both is obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a contact inspection device according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing a contact inspection device according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing a contact inspection device according to a third embodiment of the present invention.

FIG. 4 is a block diagram showing a contact inspection device according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional contact inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk 2 Spindle 3 Spindle drive means 4 Slider 5 Arm 6 Actuator 7 Actuator drive means 8 Signal amplifying means 9 Filter 10 Display means 11 Slip ring 12 Brush 101-105 AE sensor

Claims (10)

[Claims] 1. A holding mechanism for holding and rotating a disk, a slider on which a head for recording and / or reproducing data on and from the disk is mounted, an arm moved in a predetermined direction while supporting the slider, and the slider A vibration detection element for detecting contact between the disk and the disk; and a signal transmission unit for transmitting an output signal of the vibration detection element. A contact inspection device, wherein an element is mounted on the disk. 2. A holding mechanism for holding and rotating a disk, a slider having a magnetic head for recording and / or reproducing data on and from the disk, an arm which is moved in a predetermined direction while supporting the slider, and A vibration detecting element for detecting a contact between the slider and the disk; and a signal transmitting means for transmitting an output signal of the vibration detecting element. A contact inspection device, wherein a detection element is mounted on the holding mechanism. 3. The contact inspection device according to claim 1, wherein a plurality of vibration detection elements are provided, and at least one vibration detection element is a vibration detection element that detects the contact. 4. A rotating conductor fixed to the holding mechanism and rotating with the rotation of the holding mechanism, and a contact conductor contacting the fixed body rotating with the rotation of the holding mechanism. The contact inspection device according to any one of claims 1 to 3, wherein an output signal of the vibration detection element is transmitted through a contact between the rotating conductor and a contact conductor. 5. The rotating conductor is a slip ring,
The contact inspection device according to claim 4, wherein the contact conductor is a brush. 6. A signal transmitter fixed to the holding mechanism, rotating with the rotation of the holding mechanism and transmitting a signal in the air, and receiving the signal converted by the signal transmitter. 4. The signal receiving device according to claim 1, further comprising a signal receiver, wherein the output signal of the vibration detecting element is transmitted through non-contact transmission and reception between the signal transmitter and the signal receiver. Contact inspection equipment. 7. The contact inspection device according to claim 6, wherein the signal transmitter is a rotary transformer, and the signal receiver is a fixed transformer. 8. The contact inspection device according to claim 8, wherein said vibration detecting element is an AE sensor. 9. The contact inspection device according to claim 1, wherein a fluid bearing is used for a bearing portion of the holding mechanism. 10. A holding mechanism for holding and rotating a disk, a slider having a head for recording and / or reproducing data on and from the disk, an arm that is moved in a predetermined direction while supporting the slider, and the slider. A first vibration detecting element for detecting contact between the disk and the disk, a second vibration detecting element mounted on the disk or the holding mechanism, and a first amplifying an output signal of the first vibration detecting element. Signal amplifying means, first effective value calculating means for calculating an effective value from the signal amplified by the first signal amplifying means, and whether or not the output of the first effective value calculating means has exceeded a certain value. A first signal processing circuit for judging whether or not the signal is output, a signal transmitting unit for extracting an output signal of the second vibration detecting element, and an output signal extracted by the signal transmitting unit. A second signal amplifying means, a second effective value calculating means for calculating an effective value from the signal amplified by the second signal amplifying means, and an output of the second effective value calculating means which is a constant value. A second signal processing circuit that determines whether or not the signal has exceeded the threshold value and outputs the result; and contact determination means that determines contact between the slider and the disk from output results of the two signal processing circuits. Contact inspection device characterized by the above-mentioned.