JPH02102432A - Machine for testing durability of magnetic disk medium - Google Patents
Machine for testing durability of magnetic disk mediumInfo
- Publication number
- JPH02102432A JPH02102432A JP63255073A JP25507388A JPH02102432A JP H02102432 A JPH02102432 A JP H02102432A JP 63255073 A JP63255073 A JP 63255073A JP 25507388 A JP25507388 A JP 25507388A JP H02102432 A JPH02102432 A JP H02102432A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic disk
- threshold value
- head
- disk medium
- crash
- 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 claims description 3
- 230000007257 malfunction Effects 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は磁気ディスク媒体耐久性試験機に関し、特に磁
気ディスク媒体を評価する磁気ディスク媒体耐久性試験
機に関するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk medium durability tester, and more particularly to a magnetic disk medium durability tester for evaluating magnetic disk media.
従来、この種の磁気ディスク媒体耐久性試験機は、第２
図に示すように磁気ディスク媒体１を回転すせるスピン
ドルモータ２．磁気ヘッド３を取り付けるヘッドアーム
４を有し、磁気ヘッド３を磁気ディスク媒体１にロード
させた状態でスピンドルモータ電源５をメイマー６で電
源があるサイクルでオン／オフするように操作してスピ
ンドルモータ２の起動／停止により、Ｃｏｎｔａｃｔ−
８ｔａｒｔ ／５ｔｏｐ （以下Ｃ８Ｓと称する）を行
い、これを繰υ返すことによって耐久性を評価する。Conventionally, this type of magnetic disk media durability tester has a second
As shown in the figure, a spindle motor 2 rotates the magnetic disk medium 1. It has a head arm 4 to which a magnetic head 3 is attached, and when the magnetic head 3 is loaded onto the magnetic disk medium 1, the spindle motor power supply 5 is operated by a mamer 6 to turn on/off the power supply cycle. By starting/stopping 2, Contact-
8tart/5top (hereinafter referred to as C8S) is performed and the durability is evaluated by repeating this process.
ヘッドクラッシュの検出には、ヘッドアーム４に取り付
けたＡＥ （Ａｃｏｕｓｔｉｃ Ｅｍｉｓｓｉｏｎ）セ
ンサＩでＣ８Ｓ時に磁気ヘッド３に加わる振動を電気信
号に変換したＡＥ比出力用いる。ヘッドクラッシュ判定
回路８ではこのＡＥ比出力しきい値とを比較し、しきい
値を越えた場合、ヘッドクラッシュと判定し、スピンド
ルモータ電源５を遮断するというものであった。To detect a head crash, an AE (Acoustic Emission) sensor I attached to the head arm 4 uses an AE ratio output that converts vibrations applied to the magnetic head 3 during C8S into an electrical signal. The head crash determination circuit 8 compares this AE specific output threshold value with the threshold value, and if the threshold value is exceeded, a head crash is determined and the spindle motor power supply 5 is shut off.
上述し念従来の磁気ディスク媒体耐久性試験機は、ヘッ
ドクラッシュの検出にＡＥ比出力しきい値との比較とい
う方式を用いているために１回でもＡＥ比出力しきい値
を越えると、クラッシュと判定してしまうので、ノイズ
等による誤動作が多いという問題があった。As mentioned above, conventional magnetic disk media durability testers use a method of comparison with the AE specific output threshold to detect head crashes, so if the AE specific output threshold is exceeded even once, a crash will occur. Therefore, there is a problem in that there are many malfunctions due to noise or the like.
本発明の磁気ディスク媒体耐久性試験機は、従来の試験
機の問題を改善するものであり、ヘッドクラッシュ検出
に１サイクルのＣ３Ｓ期間内でＡＥ比出力しきい値を越
える回数で判定するヘッドクラッシュ判定回路を設けた
ことにある。The magnetic disk media durability tester of the present invention improves the problems of conventional testers, and detects head crashes by determining the number of times the AE specific output threshold is exceeded within the C3S period of one cycle. The reason lies in the provision of a judgment circuit.
第３図はＩＣ８Ｓサイクルの正常時（同図（ａ））ノイ
ズを含む場合（同図（ｂ））及びヘッドクラッシュ時（
同図（Ｃ））のＡＥ比出力波形をスピンドモータの回転
数（同図（ｄ））と対応させて示した図である。Figure 3 shows the IC8S cycle when it is normal ((a) in the same figure), when it includes noise ((b) in the same figure), and when there is a head crash (((b) in the same figure).
It is a diagram showing the AE specific output waveform in (C) in the same figure in correspondence with the rotational speed of the spindle motor ((d) in the same figure).
ノイズは単発的な信号であるが、ヘッドクラッシュ時の
ＡＥ比出力ある程度の出力が連続する信号である。本発
明に係わるヘッドクラッシュ判定回路には、１サイクル
のＣ８Ｓ期間内でしきい値を越える信号が複数個必要で
あるため、ノイズとヘッドクラッシュ時のＡＥ比出力を
容易に区別できる。Although the noise is a one-shot signal, it is a signal that continuously outputs a certain amount of AE ratio output at the time of a head crash. Since the head crash determination circuit according to the present invention requires a plurality of signals that exceed a threshold value within the C8S period of one cycle, it is possible to easily distinguish between noise and the AE ratio output at the time of a head crash.
次に本発明について図面を参照して説明する。 Next, the present invention will be explained with reference to the drawings.
第１図は本発明の磁気ディスク媒体耐久性試験機の一実
施例を示すクラッシュ判定回路のブロック図である。同
図において、ＡＥセンサ７のＡＥ比出力ヘッドクラッシ
ュ判定回路８′に入力されてフィルター９を通シアンブ
１０で増幅され、コンパレーター１１でしきい値と比較
される。ＡＥ比出力しきい値を越え次場合、ワンショッ
ト回路１２から１つのパルスがカウンタ恐１３に出力さ
れる。FIG. 1 is a block diagram of a crash determination circuit showing an embodiment of the magnetic disk medium durability tester of the present invention. In the figure, the AE ratio output of the AE sensor 7 is input to a head crash determination circuit 8', passed through a filter 9, amplified by a amplifier 10, and compared with a threshold value by a comparator 11. When the AE ratio output threshold is exceeded, one pulse is output from the one-shot circuit 12 to the counter 13.
カウンタ１３では、１サイクルのＣ８Ｓ期間内のパルス
数が積算され、コンパレーター１４のしきい値と比較さ
れ、しきい値を越えた場合、クラッシュと判定して第２
図におけるスピンドルモーター電源５を遮断する。The counter 13 integrates the number of pulses within the C8S period of one cycle and compares it with the threshold value of the comparator 14. If the threshold value is exceeded, it is determined that a crash has occurred and a second
The spindle motor power supply 5 in the figure is cut off.
以上説明したように本発明は、磁気ディスク媒体耐久性
試験機のヘッドクラッシュ検出に１サイクルのＣ８Ｓ期
間内でＡＥ比出力しきい値を越える回数で判定する共ク
ラッシュ判定回路を設けたことにより、ノイズによる誤
動作を防ぐことができ、磁気ディスク媒体の耐久性を正
確に評価できる効果がある。As explained above, the present invention provides head crash detection in a magnetic disk media durability tester by providing a co-crash determination circuit that determines the number of times the AE specific output threshold is exceeded within one C8S period of one cycle. This has the effect of preventing malfunctions due to noise and allowing accurate evaluation of the durability of magnetic disk media.
第１図は本発明の一実施例による磁気ディスク媒体耐久
性試験機のヘッドクラッシュ判定回路のブロック図、第
２図は従来の磁気ディスク媒体耐久性試験機の構成を示
す図、第３図（ａ）は正常時のＡＥ比出力波形を示す図
、第３図（ｂ）はノイズを含んだ場合のｋＥ出力の波形
を示す図、第３図（ｃ）はヘッドクラッシュ時のＡＥ比
出力波形を示す図、第３図（ｄ）はスピンドルモータ電
源のオン／オフに対応したスピンドルモータ回転数を示
す図である。
１・・・・磁気ディスク媒体、２・・・・スピンドルモ
ータ、３・・・・磁気ヘッド、４・・・・ヘンドアーム
、５・・・・スピンドルモータ電源、６・・・・タイマ
、７Φ・・・ＡＥセンサ、８′・・・・ヘッドクラッシ
ュ判定回路、９・・・・フィルタ、１０・・・・アンプ
、１１・・・・コンパレータ、１２・・・・ワンショッ
ト回路、１３・・・・カウンタ、１４・・・・コンパレ
ータ。FIG. 1 is a block diagram of a head crash determination circuit of a magnetic disk media durability tester according to an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of a conventional magnetic disk media durability tester, and FIG. a) is a diagram showing the AE specific output waveform during normal conditions, FIG. 3(b) is a diagram showing the kE output waveform when noise is included, and FIG. 3(c) is the AE specific output waveform during a head crash. FIG. 3(d) is a diagram showing the spindle motor rotation speed corresponding to on/off of the spindle motor power supply. 1...Magnetic disk medium, 2...Spindle motor, 3...Magnetic head, 4...Hend arm, 5...Spindle motor power supply, 6...Timer, 7Φ. ...AE sensor, 8'...Head crash determination circuit, 9...Filter, 10...Amplifier, 11...Comparator, 12...One-shot circuit, 13...・Counter, 14... Comparator.
Claims (1)
／ストップ方式により磁気ディスク媒体の耐久性を評価
する磁気ディスク媒体耐久性試験機において、ＡＥセン
サによりヘッドクラッシュを検出するとともに１サイク
ルのコンタクトスタート／ストップ期間内でＡＥセンサ
出力がしきい値を越える回数を判定するヘッドクラッシ
ュ判定回路を設けたことを特徴とする磁気ディスク媒体
耐久性試験機。In a magnetic disk media durability tester that evaluates the durability of a magnetic disk medium using a contact start/stop method between a magnetic disk medium and a magnetic head, an AE sensor detects a head crash, and within one cycle of contact start/stop period. A magnetic disk media durability tester comprising a head crash determination circuit for determining the number of times an AE sensor output exceeds a threshold value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63255073A JPH02102432A (en) | 1988-10-11 | 1988-10-11 | Machine for testing durability of magnetic disk medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63255073A JPH02102432A (en) | 1988-10-11 | 1988-10-11 | Machine for testing durability of magnetic disk medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH02102432A true JPH02102432A (en) | 1990-04-16 |
Family
ID=17273760
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63255073A Pending JPH02102432A (en) | 1988-10-11 | 1988-10-11 | Machine for testing durability of magnetic disk medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02102432A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002211932A (en) * | 2000-11-17 | 2002-07-31 | Carl Zeiss Stiftung | Dissolving equipment for making high uv transmittable glass and method for the same |
| US6822821B2 (en) * | 2001-01-19 | 2004-11-23 | Seagate Technology Llc | Method and apparatus for predicting a head crash in a disc drive |
-
1988
- 1988-10-11 JP JP63255073A patent/JPH02102432A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002211932A (en) * | 2000-11-17 | 2002-07-31 | Carl Zeiss Stiftung | Dissolving equipment for making high uv transmittable glass and method for the same |
| US6822821B2 (en) * | 2001-01-19 | 2004-11-23 | Seagate Technology Llc | Method and apparatus for predicting a head crash in a disc drive |
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