JPH02282911A - Effective gap range finding method for magnetic head - Google Patents

Effective gap range finding method for magnetic head

Info

Publication number
JPH02282911A
JPH02282911A JP10523689A JP10523689A JPH02282911A JP H02282911 A JPH02282911 A JP H02282911A JP 10523689 A JP10523689 A JP 10523689A JP 10523689 A JP10523689 A JP 10523689A JP H02282911 A JPH02282911 A JP H02282911A
Authority
JP
Japan
Prior art keywords
recording
frequency
magnetic head
floppy disk
effective gap
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
JP10523689A
Other languages
Japanese (ja)
Inventor
Norio Miyauchi
則雄 宮内
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.)
Citizen Watch Co Ltd
Original Assignee
Citizen Watch Co Ltd
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 Citizen Watch Co Ltd filed Critical Citizen Watch Co Ltd
Priority to JP10523689A priority Critical patent/JPH02282911A/en
Publication of JPH02282911A publication Critical patent/JPH02282911A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To improve accuracy by setting a recording frequency equal to a frequency when a magnetic head is used in a floppy disk drive, performing recording and reproduction by varying a rotational frequency, and finding the effective gap range of the magnetic head from the rotational frequency of a floppy disk in which the minimum reproducing output can be obtained. CONSTITUTION:The recording frequency is fixed at the frequency when the magnetic head 101 is used in the floppy disk drive, and the recording and repro duction are performed at every varying of the rotational frequency of the floppy disk 102 by a rotational frequency setting circuit 104, and the effective gap range is found from the rotational frequency of the floppy disk 102 in which the minimum reproducing output can be obtained based on a prescribed equation. In such a manner, the rising of a recording current can be accelerated, and measurement with high accuracy can be easily performed.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明はフレキシブルディスクを用いた磁気記憶装置用
磁気ヘッドの実効ギャップ長測定方法の改良に関するも
のである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an improvement in a method for measuring the effective gap length of a magnetic head for a magnetic storage device using a flexible disk.

〔従来の技術〕[Conventional technology]

近年、フレキシブルディスクを用いた磁気記憶装置の高
記憶容量化が進展し、これらの装置に使用される磁気ヘ
ッドの記録、再生ギャップ長はサブミクロンの領域に入
ってきており、前記の磁気ヘッドの実効ギャップ長を精
度よく測定できる測定方法が望まれている。
In recent years, the storage capacity of magnetic storage devices using flexible disks has increased, and the recording and reproducing gap lengths of the magnetic heads used in these devices have entered the submicron range. A measurement method that can accurately measure the effective gap length is desired.

従来、この種の磁気ヘッドの実効ギャップ長の測定に用
いられる測定方法は、第7図に示されるように、磁気ヘ
ッド201と情報の記録、再生に使われるフロッピーデ
ィスク202とフロッピーディスクを回転するスピンス
タンド206とスピンスタンドの回転周波数を設定する
回転周波数設定回路204と記録周波数をもつ記録信号
を発生するオシレータ209と前記フロッピーディスク
202に前記磁気へクド201によって情報を記録する
ために使われる記録回路208と前記磁気ヘッド201
の再生出力を増幅する再生回路205と再生画、路の出
力から記録周波数成分を取り出すスペクトロアナライザ
206と前記記録周波数の設定、制御及び前記スペクト
ロアナライザ206の出力の前記記録周波数特性から前
記磁気ヘッドの実効ギャップ長を求めるコンピュータ2
07の構成からなっている。
Conventionally, the measuring method used to measure the effective gap length of this type of magnetic head is to rotate a magnetic head 201, a floppy disk 202 used for recording and reproducing information, and a floppy disk, as shown in FIG. A spinstand 206, a rotational frequency setting circuit 204 that sets the rotational frequency of the spinstand, an oscillator 209 that generates a recording signal having a recording frequency, and an oscillator 209 that is used to record information on the floppy disk 202 by the magnetic head 201. Recording circuit 208 and the magnetic head 201
A reproduction circuit 205 that amplifies the reproduction output of the reproduced image, a spectro analyzer 206 that extracts the recording frequency component from the output of the reproduced image, and a spectro analyzer 206 that sets and controls the recording frequency and determines the characteristics of the magnetic head from the recording frequency characteristics of the output of the spectro analyzer 206. Computer 2 to find effective gap length
It consists of 07 configurations.

ここで、フロッピーディスク202の回転周波数は、当
該磁気ヘッド201がフロッピーディスクドライブで使
用されるときのフロッピーディスク2020回転周波数
に回転周波数設定回路204で設定される。
Here, the rotation frequency of the floppy disk 202 is set by the rotation frequency setting circuit 204 to the rotation frequency of the floppy disk 2020 when the magnetic head 201 is used in a floppy disk drive.

第8図は従来の実効ギャップ長測定方法の一例のフロー
チャート図であり、測定は次の手順で行う。まず、当該
磁気ヘッドが搭載されるフロッピーディスクドライブの
フロッピーディスクの回転周波数を設定して、コンビエ
ータによって設定された記録周波数をもつ記録信号をオ
シレータによってIEし、フロッピーディスクへの記録
、再生を行ない、再生出力からスペクトルアナライザに
よって記録周波数成分のみを取出し、前記記録周波数成
分をディジタル化しコンピュータのメモリへ取込む。再
生出力が極小となる記録周波数が求まるまで、前記の記
録周波数の設定、記録、再生、をくりかえす。再生出力
が極小となる記録周波数が求まれば、以下に示す関係式
を使いコンピュータによって当該磁気ヘッドの実効ギャ
ップ長を求める。前記のフロッピーディスクの回転周波
数と再生出力が極小となる記録周波数から、再生出力の
極小となるフロッピーディスクのメディア上へ記録され
た連続磁化反転パターンの波長を次式(1)により求め
る。
FIG. 8 is a flowchart of an example of a conventional effective gap length measuring method, and the measurement is performed in the following steps. First, the rotational frequency of the floppy disk of the floppy disk drive in which the magnetic head is mounted is set, and a recording signal having the recording frequency set by the combiator is IE'd by the oscillator to perform recording and reproduction on the floppy disk. A spectrum analyzer extracts only the recording frequency component from the reproduced output, digitizes the recording frequency component, and imports it into the memory of the computer. The above-mentioned recording frequency setting, recording, and reproduction are repeated until the recording frequency at which the reproduction output becomes minimum is determined. Once the recording frequency at which the reproduction output is minimum is determined, the effective gap length of the magnetic head is determined by a computer using the relational expression shown below. From the rotational frequency of the floppy disk and the recording frequency at which the reproduction output becomes minimum, the wavelength of the continuous magnetization reversal pattern recorded on the floppy disk medium at which the reproduction output becomes minimum is determined by the following equation (1).

/l m= 2 x r f r / fmix   
      −−−(1)ここで、rは当該磁気ヘッド
の記録、再生ギャップ部のフロッピーディスクの中心か
らの距離、frはフロッピーディスクの回転周波数、f
min。
/l m= 2 x r f r / fmix
--- (1) Here, r is the distance from the center of the floppy disk to the recording/reproducing gap of the magnetic head, fr is the rotational frequency of the floppy disk, f
min.

λ朋はそれぞれ再生出力の極小となる記録周波数、フロ
ッピーディスクのメディア上の連続磁化反転パターン波
長である。
λ is the recording frequency at which the reproduction output is minimum, and the continuous magnetization reversal pattern wavelength on the floppy disk medium.

また、実効ギャップ長g i t rとAmとの間には
、記録、再生に関する相反定理を適用した記録、再生の
線型理論から、 got t ”0.89Xλmin         
−(2)との関係式があり、上記の(1)、(2)式か
ら、実効ギャップ長は、 g e r t ”0.89X2πr f r/ f7
     ・=(3)と求まる。ここで、0.89は相
反定理を適用した記録、再生の線型理論から導出される
係数である。
Furthermore, from the linear theory of recording and reproduction applying the reciprocity theorem regarding recording and reproduction, the effective gap length g i tr and Am are determined as got t ”0.89Xλmin
- (2), and from the above equations (1) and (2), the effective gap length is g e r t ”0.89X2πr f r/ f7
・=(3) is found. Here, 0.89 is a coefficient derived from the linear theory of recording and reproduction applying the reciprocity theorem.

第9図は、従来のフロッピー磁気ヘッドの実効ギャップ
測定方法で、記録周波数を変えるごとに記録、再生を行
ない、再生出力データをとったときの、前記再生出力の
記録周波数特性の概念図である。
FIG. 9 is a conceptual diagram of the recording frequency characteristics of the reproduction output when recording and reproduction are performed each time the recording frequency is changed and reproduction output data is taken using the conventional method of measuring the effective gap of a floppy magnetic head. .

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

しかしながら、従来の磁気ヘッドの実効ギャップ長測定
方法では、第4図(a)に示す、フロッピーディスクド
ライブでの記録周波数の場合、記録電流は十分早(立上
がるが、一方、第4図(b)に示す再生出力が極小とな
る付近の記録周波数の場合、磁気ヘッドの記録コイルの
インダクタンスのために記録電流の立上がりがおくれ、
設定電流にならないうちに2つの記録コイルの記録電流
切り換え時間がきてしまうという現象が発生していた。
However, in the conventional method for measuring the effective gap length of a magnetic head, at the recording frequency of a floppy disk drive shown in FIG. 4(a), the recording current rises sufficiently early (rises); ), the rise of the recording current is delayed due to the inductance of the recording coil of the magnetic head.
A phenomenon occurred in which the recording current switching time for the two recording coils came before the set current was reached.

その結果、上記の記録周波数付近ではフロッピーディス
クのメディアへ記録された連続磁化反転パターンの磁化
反転が十分メディアの深部まで達しないことによって、
再生出力が不十分で、再生出力対ノイズ比(S/N )
を十分とれず、前記波長から求めた実効ギャップ長の測
定精度が悪いという課題があった。
As a result, near the above recording frequency, the magnetization reversal of the continuous magnetization reversal pattern recorded on the floppy disk medium does not reach deep enough into the medium.
Insufficient playback output, playback output to noise ratio (S/N)
There was a problem in that the measurement accuracy of the effective gap length obtained from the wavelength was poor.

本発明は、上記課題に対してなされたもので、磁気ヘッ
ドの実効ギャップ長を十分な精度で測定できる磁気ヘッ
ドの実効ギャップ長測定方法を提供することを目的とし
ている。
The present invention has been made to address the above-mentioned problems, and an object of the present invention is to provide a method for measuring the effective gap length of a magnetic head that can measure the effective gap length of a magnetic head with sufficient accuracy.

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

本発明は、記録周波数は当該磁気ヘッドがフロッピーデ
ィスクドライブに搭載されて使用されるときの記録周波
数に設定、固定し、一方、スピンドルスタンドの回転周
波数設定回路をコンピュータで制御し、フロッピーディ
スクの回転周波数を可変にし、また、記録周波数を中心
周波数にもつ狭帯域フィルタ106、狭帯域フィルタの
出力をアナログ−ディジタルに変換するA−D変換器1
07を設け、記録周波数を当該磁気ヘッドがフロッピー
ディスクドライブで使われるときの記録周波数に等しく
シ、フロッピーディスクの回転周波数を変えるごとに記
録、再生を行ない、再生出力の啄小となるフロッピーデ
ィスクの回転周波数から磁気ヘッドの実効ギャップ長測
定することにある。
In the present invention, the recording frequency is set and fixed at the recording frequency when the magnetic head is installed in a floppy disk drive and used, and the rotation frequency setting circuit of the spindle stand is controlled by a computer to rotate the floppy disk. A narrowband filter 106 whose frequency is variable and whose center frequency is the recording frequency, and an A-D converter 1 which converts the output of the narrowband filter from analog to digital.
07, the recording frequency is set equal to the recording frequency when the magnetic head is used in a floppy disk drive, recording and reproduction are performed each time the rotational frequency of the floppy disk is changed, and the output of the floppy disk becomes smaller. The purpose is to measure the effective gap length of a magnetic head from the rotational frequency.

〔実施例〕〔Example〕

第1図は本発明になる磁気ヘッドの実効ギャップ長測定
方法を示す回路ブロック図であり、磁気ヘッド101と
コンピュータ108の制御による回転周波数設定回路1
04によって回転周波数を設定される、フロッピーディ
スク102を回転するスピンスタンド106と記録周波
数を固定したオシレータ110と記録回路109と再生
回路105、狭帯域フィルタ106、A−D変換器10
7、コンピュータ108の構成からなっている。
FIG. 1 is a circuit block diagram showing a method for measuring the effective gap length of a magnetic head according to the present invention, and shows a rotation frequency setting circuit 1 controlled by a magnetic head 101 and a computer 108.
04, a spinstand 106 that rotates a floppy disk 102, an oscillator 110 with a fixed recording frequency, a recording circuit 109, a reproducing circuit 105, a narrowband filter 106, and an A-D converter 10.
7. Consists of the configuration of a computer 108.

ここで、記録周波数は、当該磁気ヘッドがフロッピーデ
ィスクドライブで使用されるときの記録周波数に設定、
固定されており、フロッピーディスクの回転周波数を変
えるごとに記録、再生を行い、再生出力の極小となるフ
ロッピーディスクの回転周波数から下記の関係式(4)
にもとづき実効ギャップ長を求めることができる。
Here, the recording frequency is set to the recording frequency when the magnetic head is used in a floppy disk drive.
The rotational frequency of the floppy disk is fixed, and recording and playback are performed each time the rotational frequency of the floppy disk is changed. From the rotational frequency of the floppy disk at which the playback output becomes minimum, the following relational expression (4) is obtained.
Based on this, the effective gap length can be determined.

g e t t =0.89 X 2πr f rmi
n/ f    −(4)ここで、gaffは実効ギャ
ップ長、0.89は相反定理を適用した記録、再生の線
型理論から導出される係数、rは、当該フロッピー磁気
ヘッドの記録、再生ギャップ部のフロッピーディスク中
心からの距離、frminは再生出力の極小となるフロ
ッピーディスクの回転周波数、fは記録周波数である。
g e t t =0.89 X 2πr f rmi
n/f - (4) where gaff is the effective gap length, 0.89 is a coefficient derived from the linear theory of recording and reproduction applying the reciprocity theorem, and r is the recording and reproduction gap portion of the floppy magnetic head. is the distance from the center of the floppy disk, frmin is the rotational frequency of the floppy disk at which the playback output is minimum, and f is the recording frequency.

第3図は、本発明になるフロッピー磁気ヘッドの実効ギ
ャップ長測定方法で、回転周波数を変えるごとに、記録
再生を行ない、再生出力データをとったときの、前記再
生出力の回転周波数特性の概念図である。
FIG. 3 shows the method for measuring the effective gap length of a floppy magnetic head according to the present invention, and the concept of the rotational frequency characteristics of the reproduction output when recording and reproduction are performed each time the rotational frequency is changed and reproduction output data is taken. It is a diagram.

第5図は、本発明(実線)、従来(破線)のフロッピー
磁気ヘッドの実効ギャップ長の測定方法による、再生出
力/ノイズのメディア上の連続磁化反転パターンの記録
波長λ特性の模式図である。
FIG. 5 is a schematic diagram of the recording wavelength λ characteristics of continuous magnetization reversal patterns on the media of reproduction output/noise by the method of measuring the effective gap length of a floppy magnetic head according to the present invention (solid line) and the conventional method (broken line). .

本発明の測定方法によるフロッピー磁気ヘッドの再生出
力は従来のそれにくらべて大きくとれることから、再生
出力が極小となるメディア上の連続磁化反転パターンの
記録波長の測定精度は、再生出力/ノイズのOdB レ
ベルでくらべてみると、本発明の測定方法での前記記録
波長の測定精度は、従来のそれにくらべ数倍よ(なって
いる。
Since the reproduction output of the floppy magnetic head using the measurement method of the present invention can be larger than that of the conventional one, the measurement accuracy of the recording wavelength of the continuous magnetization reversal pattern on the media where the reproduction output is minimal is OdB of the reproduction output/noise. Comparing the levels, the measurement accuracy of the recording wavelength using the measurement method of the present invention is several times higher than that of the conventional method.

第6図は本発明になるフロッピー磁気ヘッドの実効ギャ
ップ長測定方法を使用して測定した実測例で、3.5.
2MB用フロッピー磁気ヘッドの再生出力のメディア上
の連続磁化反転パターンの記録波長特性である。実効ギ
ャップ長は、0.91±0.02μと求まり、十分な測
定精度であると考えられる。ちなみに記録周波数は25
0 kHzである。
FIG. 6 shows an example of actual measurement using the method for measuring the effective gap length of a floppy magnetic head according to the present invention.
This is the recording wavelength characteristic of a continuous magnetization reversal pattern on the medium of the reproduction output of a 2MB floppy magnetic head. The effective gap length was found to be 0.91±0.02μ, which is considered to have sufficient measurement accuracy. By the way, the recording frequency is 25
It is 0 kHz.

〔発明の効果〕〔Effect of the invention〕

以上の詳細な説明によって示されたように、本発明にな
るフロッピー磁気ヘッドの実効ギャップ長測定方法では
、上記磁気ヘッドの実効ギャップ長の測定を、上記磁気
ヘッドがフロッピーディスクドライブに使われるときの
記録周波数で行えるので、記録電流の立上がりを改善す
るために、実用の磁気ヘッドにくらべて記録コイルの巻
数を1/3タ一ン程度に少なくした磁気ヘッドを特別に
用意したり、またスペクトルアナライザ等の高価な測定
器を使用することなく、上記磁気ヘッドの実効ギャップ
長を測定で鰺、実効ギャップ長の電子顕微鏡等で測定し
てギャップ長からの増加分を調べることができるので、
ギヤツブ部形成のためのガラス接合条件へのフィードバ
ックを容易ならしむる効果を有している。
As shown in the above detailed explanation, in the method for measuring the effective gap length of a floppy magnetic head according to the present invention, the effective gap length of the magnetic head is measured when the magnetic head is used in a floppy disk drive. Since it can be performed at the recording frequency, in order to improve the rise of the recording current, we have specially prepared a magnetic head with the number of turns of the recording coil reduced to about 1/3 of that of a practical magnetic head, and a spectrum analyzer. The effective gap length of the magnetic head can be measured using an electron microscope, etc., and the increase from the gap length can be investigated without using expensive measuring instruments such as
This has the effect of facilitating feedback to the glass bonding conditions for forming the gear part.

更に、ハードディスクドライブ用磁気へクド、ビデオ用
磁気ヘッド等に対しても本発明は適用でき、フロッピー
磁気ヘッドと同様に、ギヤツブ部形成のためのガラス接
合条件へのフィードバックを容易ならしむる効果を有し
ている。
Furthermore, the present invention can also be applied to magnetic heads for hard disk drives, magnetic heads for video, etc., and has the effect of facilitating feedback to the glass bonding conditions for forming gear parts, similar to floppy magnetic heads. have.

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

第1図は本発明になる一実施例を示す実効ギャップ測定
方法の回路ブロック図、第2図は本発明になる一実施例
を示す実効ギャップ長測定方法のフローチャート図、第
3図は本発明の測定したときの再生出力対ディスク回転
周波数特性の概念図、第4図(al、 (b)は磁気ヘ
ッドの記録コイルに流れる記録電流の時間依存性を示す
グラフ、第5図は本発明(実線)、従来(破線)の実効
ギャップ長の測定方法による、再生出力/ノイズのメデ
ィア上の連続磁化反転パターンの記録波長λ特性の模式
図、第6図は本発明の測定した実測例を示すグラフであ
り、第7図は従来の実効ギャップ測定方法の一例の回路
ブロック図、第8図は従来の実効ギヤツブ測定方法の一
例のフローチャート図、第9図は従来の測定したときの
再生出力対記録周波数特性の概念図である。 第1閃 第3図 第4図 (a) 第5図 0.70 0,90 1+o  t、30−。 メチで−ヒの鏝」兜δ良化反転パターンの言8釧す支畏
八第6図 第7図
FIG. 1 is a circuit block diagram of an effective gap measuring method showing an embodiment of the present invention, FIG. 2 is a flowchart of an effective gap length measuring method showing an embodiment of the present invention, and FIG. 3 is a circuit block diagram of an effective gap measuring method showing an embodiment of the present invention. 4(a) and 4(b) are graphs showing the time dependence of the recording current flowing through the recording coil of the magnetic head, and FIG. Figure 6 shows an actual measurement example measured by the present invention. Fig. 7 is a circuit block diagram of an example of a conventional effective gap measurement method, Fig. 8 is a flowchart of an example of a conventional effective gear measurement method, and Fig. 9 shows a reproduction output vs. when measured using the conventional method. This is a conceptual diagram of the recording frequency characteristics. Figure 1, Figure 3, Figure 4 (a) Figure 5, 0.70 0,90 1+o t, 30-. Figure 8, Figure 6, Figure 7

Claims (1)

【特許請求の範囲】[Claims] フレキシブルディスクを用いた磁気記憶装置用磁気ヘッ
ドの実効ギャップ長測定方法において、磁気ヘッドの記
録周波数は通常使用時の記録周波数に設定し、フレキシ
ブルディスクは回転周波数を可変可能にし、前記回転周
波数の変化に応じて前記フレキシブルディスクへの記録
・再生を行い、上記回転周波数と記録周波数から再生出
力が極小なる記録された連続磁化反転パターンの波長を
求め、該波長から演算処理して実効ギャップ長を測定す
ることを特徴とする磁気ヘッドの実効ギャップ長測定方
法。
In a method for measuring the effective gap length of a magnetic head for a magnetic storage device using a flexible disk, the recording frequency of the magnetic head is set to the recording frequency during normal use, the rotational frequency of the flexible disk is made variable, and the rotational frequency is changed. Recording and reproduction are performed on the flexible disk according to the rotational frequency and the recording frequency, and the wavelength of the recorded continuous magnetization reversal pattern at which the reproduction output is minimal is determined from the rotational frequency and the recording frequency, and the effective gap length is measured by performing arithmetic processing from the wavelength. A method for measuring an effective gap length of a magnetic head, characterized in that:
JP10523689A 1989-04-25 1989-04-25 Effective gap range finding method for magnetic head Pending JPH02282911A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10523689A JPH02282911A (en) 1989-04-25 1989-04-25 Effective gap range finding method for magnetic head

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10523689A JPH02282911A (en) 1989-04-25 1989-04-25 Effective gap range finding method for magnetic head

Publications (1)

Publication Number Publication Date
JPH02282911A true JPH02282911A (en) 1990-11-20

Family

ID=14402018

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10523689A Pending JPH02282911A (en) 1989-04-25 1989-04-25 Effective gap range finding method for magnetic head

Country Status (1)

Country Link
JP (1) JPH02282911A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4963221A (en) * 1986-09-29 1990-10-16 Kabushiki Kaisha Meiki Seisakusho Hot press including cam rod penetrating top platen

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4963221A (en) * 1986-09-29 1990-10-16 Kabushiki Kaisha Meiki Seisakusho Hot press including cam rod penetrating top platen

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