JPH0352177A - Method for evaluating characteristic of magnetic disk head - Google Patents
Method for evaluating characteristic of magnetic disk headInfo
- Publication number
- JPH0352177A JPH0352177A JP18607189A JP18607189A JPH0352177A JP H0352177 A JPH0352177 A JP H0352177A JP 18607189 A JP18607189 A JP 18607189A JP 18607189 A JP18607189 A JP 18607189A JP H0352177 A JPH0352177 A JP H0352177A
- Authority
- JP
- Japan
- Prior art keywords
- head
- magnetic disk
- medium
- vibration
- vacuum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims description 18
- 238000012360 testing method Methods 0.000 claims abstract description 7
- 238000001514 detection method Methods 0.000 claims abstract description 5
- 238000007667 floating Methods 0.000 claims abstract description 5
- 238000012544 monitoring process Methods 0.000 claims abstract description 3
- 230000002093 peripheral effect Effects 0.000 abstract description 4
- 230000003247 decreasing effect Effects 0.000 abstract 1
- 238000011156 evaluation Methods 0.000 description 5
- 230000001133 acceleration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000005339 levitation Methods 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000012795 verification Methods 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔概 要〕
磁気ディスク装置の信頼性に関与する磁気ディスクヘッ
ドの浮上．摺動特性の評価方法に関し、実機の媒体を使
用しかつ実機の周速でヘッドの浮上，摺動特性を評価し
て装置の信頼性向上に役立たせるようにすることを目的
とし、
回転する媒体上に磁気ディスクヘッドを浮上させ、次第
に周囲環境の空気圧を低下させて行く過程において、前
記磁気ディスクヘッドの振動を圧電素子により検出し、
この検出信号をモニターして該磁気ディスクヘッドの浮
上、摺動特性を評価するようにした構或とする。[Detailed Description of the Invention] [Summary] The levitation of a magnetic disk head is related to the reliability of a magnetic disk device. Regarding the evaluation method of sliding characteristics, the purpose of this study is to evaluate the flying and sliding characteristics of the head using the actual media and at the circumferential speed of the actual device, which will be useful for improving the reliability of the device. In the process of floating the magnetic disk head above and gradually lowering the air pressure of the surrounding environment, detecting the vibration of the magnetic disk head with a piezoelectric element,
The detection signal is monitored to evaluate the flying and sliding characteristics of the magnetic disk head.
本発明は磁気ディスク装置の信頼性に関与する磁気ディ
スクヘッドの浮上，摺動特性の評価方法．に関するもの
である。The present invention is a method for evaluating the flying and sliding characteristics of magnetic disk heads, which are involved in the reliability of magnetic disk drives. It is related to.
磁気ディスク装置の信頼性に関与する従来の磁気ディス
クヘッド評価方法としては、浮上バランスの測定や、磁
気ディスクヘッドを支持するヘッドアーム加振によるヘ
ッド振動の周波数及び加速度の測定等（前者の方法）が
挙げられる。Conventional methods for evaluating magnetic disk heads that are related to the reliability of magnetic disk drives include measuring the flying balance and measuring the frequency and acceleration of head vibrations caused by excitation of the head arm that supports the magnetic disk head (the former method). can be mentioned.
また、ＣＳＳ （コンタクトスタートストップ）時のヘ
ッドの振動を圧電素子の出力で評価する方法（後者の方
法）も知られている。Furthermore, a method (the latter method) is also known in which head vibration during CSS (contact start/stop) is evaluated using the output of a piezoelectric element.
しかし、前者の方法は、いずれもガラス円板を使用した
ものであって実機の媒体は使用できず、また後者の方法
は、ある周速に達するとヘッドが浮上してしまうため、
ヘッドが浮上する周速以上の領域では評価できない。However, the former method uses a glass disk and cannot use the actual media, and the latter method causes the head to float when it reaches a certain circumferential speed.
Evaluation cannot be made in the region above the circumferential speed at which the head flies.
本発明は実機の媒体を使用しかつ実機の周速でヘッドの
浮上、摺動特性を試験して装置の信頼性向上に役立たせ
ることのできる磁気ディスクヘッドの特性評価方法を提
供することを目的としている。An object of the present invention is to provide a method for evaluating the characteristics of a magnetic disk head that can be useful for improving the reliability of the device by testing the flying and sliding characteristics of the head using the actual media and at the peripheral speed of the actual device. It is said that
上述の目的を達戒するため、本発明では、回転する媒体
上に磁気ディスクヘッドを浮上させ、次第に周囲環境の
空気圧を低下させて行く過程において、前記磁気ディス
クヘッドの振動を圧電素子により検出し、この検出信号
をモニターして該磁気ディスクヘッドの浮上，摺動特性
を評価するようにした構戒とする。In order to achieve the above-mentioned object, the present invention detects vibrations of the magnetic disk head using a piezoelectric element in the process of floating the magnetic disk head above a rotating medium and gradually lowering the air pressure of the surrounding environment. This detection signal is monitored to evaluate the flying and sliding characteristics of the magnetic disk head.
以下、図面に関連して本発明の実施例を説明する。 Embodiments of the invention will be described below with reference to the drawings.
第１図は本発明の磁気ディスクヘッドの特性評価方法を
実施するための試験器の構造概要説明図で、図中、１は
図示しない駆動源により駆動されるスピンドル２に支持
されて回転する媒体、３はジンバル等の弾性体４により
片持状に支持されて媒体１に対向する磁気ディスクヘッ
ド（以下ヘッドと略称する）、５はヘッド３の振動を検
出する圧電素子で、これらの各部材は、真空ポンプ６に
接続する真空容器７内に配置されている．真空容器７に
は真空計８が取り付けられている。また、９は圧電素子
５に接続する増幅器、１０は増幅器９に接続するＲＭＳ
計（入力電圧を実効値に換算するもの）、１１はＲＭＳ
計１０及び真空計８に接続するＸ−Ｙレコーダで、これ
らは真空容器７外に配置されている。FIG. 1 is a schematic structural diagram of a tester for carrying out the magnetic disk head characteristic evaluation method of the present invention. In the figure, 1 indicates a rotating medium supported by a spindle 2 driven by a drive source (not shown). , 3 is a magnetic disk head (hereinafter referred to as head) supported in a cantilevered manner by an elastic body 4 such as a gimbal and faces the medium 1; 5 is a piezoelectric element for detecting vibrations of the head 3; is arranged in a vacuum container 7 connected to a vacuum pump 6. A vacuum gauge 8 is attached to the vacuum container 7. Further, 9 is an amplifier connected to the piezoelectric element 5, and 10 is an RMS connected to the amplifier 9.
meter (converts input voltage to effective value), 11 is RMS
This is an X-Y recorder connected to the gauge 10 and the vacuum gauge 8, which are placed outside the vacuum container 7.
このような構或の装置によるヘッド特性評価は次の手順
で行われる。Head characteristic evaluation using an apparatus having such a structure is performed in the following procedure.
試験に際しては、媒体１を回転させ、真空容器７内を次
第に減圧して行く。これにより、媒体１とヘッド３を次
第に接触させて行くが、この接触は、減圧による空気流
の減少により実現されるものである。この過程において
、ヘッド３の振動を圧電素子５により検出し、その検出
信号を増幅器９により増幅した後、ＲＭＳ計で電圧をＲ
ＭＳ値（実効値）に変えてＸ−Ｙレコーダ１ｌの例えば
Ｙ軸に入力する。一方、真空計８は真空度を電圧に変換
してＸ−Ｙレコーダｌ１の例えばＸ軸に入力する。During the test, the medium 1 is rotated and the pressure inside the vacuum container 7 is gradually reduced. As a result, the medium 1 and the head 3 are brought into contact gradually, and this contact is achieved by reducing the air flow due to the reduced pressure. In this process, the vibration of the head 3 is detected by the piezoelectric element 5, the detection signal is amplified by the amplifier 9, and then the voltage is measured by the RMS meter.
The value is changed to an MS value (effective value) and input to, for example, the Y axis of the X-Y recorder 1l. On the other hand, the vacuum gauge 8 converts the degree of vacuum into voltage and inputs it to, for example, the X axis of the X-Y recorder l1.
？上の手順により信号出力の真空度に対する変化をモニ
ターすることにより、実機の媒体及び周速でヘッドの振
動解析を行うことが可能である。? By monitoring the change in signal output with respect to the degree of vacuum using the above procedure, it is possible to analyze head vibration using the actual medium and circumferential speed of the machine.
なお、増幅器９による増幅後に、信号をオシロスコープ
で観察することも可能であり、また、ＦＦＴ （Ｆａｓ
ｔ Ｆｏｕｒｉｅｒ Ｔｒａｎｓｆｏｒｍ）やスベク
トラムアナライザにより振動周波数、加速度の解析も可
能である．
上記手順による試験結果の一例を第２図に示す。Note that it is also possible to observe the signal with an oscilloscope after amplification by the amplifier 9, and it is also possible to observe the signal with an oscilloscope.
It is also possible to analyze vibration frequency and acceleration using a tFourier Transform) or a spectrum analyzer. An example of the test results according to the above procedure is shown in FIG.
この場合の媒体は外径５吋のメタルスバンタを施したも
ので、ヘッドはＭｎ−Ｚｎフェライトである。In this case, the medium was coated with a metal banter having an outer diameter of 5 inches, and the head was made of Mn--Zn ferrite.
ここで、同一仕様のヘッドを上記手順で試験し、真空度
５０Ｔｏｒｒにおける出力信号が０．５〜０． ８■。Here, a head with the same specifications was tested according to the above procedure, and the output signal at a vacuum level of 50 Torr was 0.5 to 0. 8■.
，のもの（第２図のもの）と０．１〜０．４ｖ■，のち
のを選び出した。そして、これらのヘッドを実機に組み
入れ、ＭＴ Ｂ Ｆ （Ｍｅａｎ Ｔｉｍｅ Ｂｅｔｗ
ｅｅｎＦａｉｌｕｒｅ ：平均故障間隔）検証をした結
果は次の通りであった。但し、媒体は外径５吋のメタル
ディスクで、ヘッド位置は媒体中心より６０間の位置に
セットされ、ヘッド支持弾性体によるヘッド？ね圧は９
．２（ｇ）である。, (the one shown in Figure 2) and 0.1 to 0.4 V, later were selected. Then, by incorporating these heads into the actual machine, MT B F (Mean Time Between
eenFailure: mean time between failures) The results of the verification were as follows. However, the medium is a metal disk with an outer diameter of 5 inches, the head position is set at a position 60 degrees from the center of the medium, and the head is supported by an elastic body. Negative pressure is 9
．． 2(g).
０． ５〜０．８■■，の場合のＭＴＢＦ時間；３０，
０００ （ Ｈ ）
０．１〜０．４ＶＲＭＳの場合のＭＴＢＦ時間；５０，
０００ （ Ｈ ）
この結果に明らかなように、減圧過程においてヘッド、
媒体が摺動し始めるときの圧電素子からの出力と装置の
信頼性は密接な関係にある。すなわち、本発明により、
装置の信頼性を格段に向上させる評価方法が得られる。0. MTBF time for 5 to 0.8 ■■; 30,
000 (H) MTBF time for 0.1-0.4 VRMS; 50,
000 (H) As is clear from this result, during the depressurization process, the head,
The output from the piezoelectric element when the medium begins to slide and the reliability of the device are closely related. That is, according to the present invention,
An evaluation method that significantly improves the reliability of the device can be obtained.
以上述べたように、本発明によれば、実機の媒体を使用
しかつ実機の周速でヘッドの浮上，摺動特性を評価する
ことができ、装置の信頼性向上に役立たせることが可能
である。As described above, according to the present invention, the flying and sliding characteristics of the head can be evaluated using the actual media and at the peripheral speed of the actual machine, which can be useful for improving the reliability of the device. be.
第１図は本発明の実施例の磁気ディスクヘッドの特性評
価用試験機の構造概要説明図、第２図は第１図の装置に
よる試験結果を示すグラフで、
図中、
１は媒体、
３は磁気ディスクヘッ
５は圧電素子である，
ド、FIG. 1 is a structural schematic explanatory diagram of a testing machine for evaluating characteristics of a magnetic disk head according to an embodiment of the present invention, and FIG. 2 is a graph showing the test results by the apparatus shown in FIG. 1. In the figure, 1 is a medium, 3 The magnetic disk head 5 is a piezoelectric element.
Claims (1)
上させ、次第に周囲環境の空気圧を低下させて行く過程
において、 前記磁気ディスクヘッド（３）の振動を圧電素子（５）
により検出し、この検出信号をモニターして該磁気ディ
スクヘッド（３）の浮上、摺動特性を試験することを特
徴とする磁気ディスクヘッドの特性評価方法。[Claims] In the process of floating a magnetic disk head (3) above a rotating medium (1) and gradually lowering the air pressure of the surrounding environment, vibrations of the magnetic disk head (3) are transmitted to a piezoelectric element ( 5)
A method for evaluating characteristics of a magnetic disk head, comprising: detecting the magnetic disk head (3) by detecting the magnetic disk head (3), and monitoring the detection signal to test the flying and sliding characteristics of the magnetic disk head (3).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18607189A JPH0352177A (en) | 1989-07-20 | 1989-07-20 | Method for evaluating characteristic of magnetic disk head |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP18607189A JPH0352177A (en) | 1989-07-20 | 1989-07-20 | Method for evaluating characteristic of magnetic disk head |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0352177A true JPH0352177A (en) | 1991-03-06 |
Family
ID=16181880
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP18607189A Pending JPH0352177A (en) | 1989-07-20 | 1989-07-20 | Method for evaluating characteristic of magnetic disk head |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0352177A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5824920A (en) * | 1995-10-27 | 1998-10-20 | Fujitsu Limited | Apparatus for evaluating magnetic recording medium |
-
1989
- 1989-07-20 JP JP18607189A patent/JPH0352177A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5824920A (en) * | 1995-10-27 | 1998-10-20 | Fujitsu Limited | Apparatus for evaluating magnetic recording medium |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5351543A (en) | Crack detection using resonant ultrasound spectroscopy | |
| US3924456A (en) | Methods and apparatus for detecting the presence of cracks in a workpiece by the use of stress waves emitted therefrom | |
| JP3408817B2 (en) | FM detection of slider / disk interface | |
| EP0655623B1 (en) | Relative resonant frequency shifts to detect cracks | |
| US7924020B2 (en) | Free-state modal frequency response testing | |
| US6092412A (en) | Glide height test signal processor and method using increased high frequency components | |
| US5545989A (en) | Non-destructive in-situ landing velocity determination of magnetic rigid disk drives using back EMF from the spindle motor during shutdown | |
| US6330827B1 (en) | Resonant nonlinear ultrasound spectroscopy | |
| Yeack-Scranton | Novel piezoelectric transducers to monitor head-disk interactions | |
| US5824920A (en) | Apparatus for evaluating magnetic recording medium | |
| US6105432A (en) | Contact tester | |
| Jeong et al. | Natural frequencies of sliders and transducers used to detect slider-disk contacts | |
| JPS63208756A (en) | Quick acoustic radiation inspection method of pressure vessel | |
| JPH0352177A (en) | Method for evaluating characteristic of magnetic disk head | |
| US7043376B2 (en) | Vibration measurement apparatus and method | |
| US3456484A (en) | Transducer calibration system | |
| Grabec et al. | A comparison of high-performance acoustic emission transducers | |
| US5668690A (en) | Method and apparatus for lifetime prediction of gas lubricated interfaces in data storage devices | |
| JP3538557B2 (en) | Contact inspection device | |
| US4455871A (en) | Method and apparatus for the non-destructive measurement of the response pressure of reversible rupture discs | |
| Kishigami et al. | An experimental investigation of contact characteristics between a slider and medium using the electrical resistance method | |
| JPH03100430A (en) | Leakage inspecting device for tank | |
| McMillan et al. | Investigation of slider take-off velocity using the acoustic emission frequency spectrum | |
| JP2682508B2 (en) | Magnetic head tester device | |
| KR100765407B1 (en) | Active vibrometer system with analyzer |