JPH02102432A - Machine for testing durability of magnetic disk medium - Google Patents

Machine for testing durability of magnetic disk medium

Info

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
Application number
JP63255073A
Other languages
Japanese (ja)
Inventor
Mitsuhiro Taki
充博 滝
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP63255073A priority Critical patent/JPH02102432A/en
Publication of JPH02102432A publication Critical patent/JPH02102432A/en
Pending legal-status Critical Current

Links

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  • Manufacturing Of Magnetic Record Carriers (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

PURPOSE:To prevent the malfunction by noises and to exactly evaluate the durability of a magnetic disk medium by providing a head crash deciding circuit which makes decision by the number of the times when an acoustic emission output exceeds the threshold value within a contact start/stop period of one cycle. CONSTITUTION:The AE output of an acoustic emission (AE) sensor 7 is inputted to the head crash deciding circuit 8, is passed through a filter 9, is amplified by an amplifier 10 and is compared with the threshold value in a comparator 11. One pulse is outputted from a one-shot circuit 12 when the AE output exceeds the threshold value. The number of pulses in the contact start/stop period of one cycle is integrated in a counter 13 and is compared with the threshold value of a comparator 14. The crash is decided when the number of pulses exceeds the threshold value. A power source 5 of a spindle motor is then turned off. The noises and the AE output at the time of the head crash are easily discriminated in this way.

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.

〔従来の技術〕[Conventional technology]

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.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

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.

〔課題を解決するための手段〕[Means to solve the problem]

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.

〔作 用〕[For production]

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.

〔実施例〕〔Example〕

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.

〔発明の効果〕〔Effect of the invention〕

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.

【図面の簡単な説明】[Brief explanation of drawings]

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)

【特許請求の範囲】[Claims] 磁気ディスク媒体と磁気ヘッドとのコンタクトスタート
/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.
JP63255073A 1988-10-11 1988-10-11 Machine for testing durability of magnetic disk medium Pending JPH02102432A (en)

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)

* Cited by examiner, † Cited by third party
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

Cited By (2)

* Cited by examiner, † Cited by third party
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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