JP2001291234A - Magnetic disk testing method - Google Patents
Magnetic disk testing methodInfo
- Publication number
- JP2001291234A JP2001291234A JP2000103174A JP2000103174A JP2001291234A JP 2001291234 A JP2001291234 A JP 2001291234A JP 2000103174 A JP2000103174 A JP 2000103174A JP 2000103174 A JP2000103174 A JP 2000103174A JP 2001291234 A JP2001291234 A JP 2001291234A
- Authority
- JP
- Japan
- Prior art keywords
- frequency
- master disk
- adhesion
- recording medium
- signal
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/86—Re-recording, i.e. transcribing information from one magnetisable record carrier on to one or more similar or dissimilar record carriers
- G11B5/865—Re-recording, i.e. transcribing information from one magnetisable record carrier on to one or more similar or dissimilar record carriers by contact "printing"
Landscapes
- Manufacturing Of Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、マスターディス
クから磁気転写方式によりサーボ信号が書き込まれる記
録メディア（磁気ディスク）の試験方法に関する。The present invention relates to a test method for a recording medium (magnetic disk) on which servo signals are written from a master disk by a magnetic transfer method.
【０００２】[0002]
【従来の技術】サーボ信号を書き込むサーボライト方式
の従来例について、図７から図１０を参照して説明す
る。まず、図7のようにメディア磁性層の上面に長手方
向の磁化を与える磁石３Ａを置き、メディア１を一方向
に磁化する（初期磁化）。その後、図8のようにメディ
ア１の磁性層上にマスターディスク４を密着させ、その
上方から初期磁化とは逆向きの磁界を与える磁石３Ｂを
置き、メディア１とマスターディスク４または磁石３Ｂ
を回転させて、メディア１に磁界を与える（転写）。2. Description of the Related Art A conventional example of a servo write method for writing a servo signal will be described with reference to FIGS. First, as shown in FIG. 7, a magnet 3A for giving magnetization in the longitudinal direction is placed on the upper surface of the medium magnetic layer, and the medium 1 is magnetized in one direction (initial magnetization). Then, as shown in FIG. 8, the master disk 4 is brought into close contact with the magnetic layer of the medium 1, and a magnet 3B for applying a magnetic field in a direction opposite to the initial magnetization is placed from above, and the medium 1 and the master disk 4 or the magnet 3B are placed.
To apply a magnetic field to the medium 1 (transfer).
【０００３】その際、図９に示すように、マスターディ
スク４上に生成されている軟磁性層パターン５に磁束が
集中することにより、軟磁性層パターン５の直下は転写
磁界の影響を受けず、初期磁化がそのまま保存される。
一方、軟磁性層パターン５のない部分の直下の磁性層
は、軟磁性層のエッジからもれる磁束の影響により、初
期磁化とは逆方向に磁化される。これにより、マスター
ディスク４上の軟磁性層パターン５に対応した磁気パタ
ーンが、メディア１に磁気転写されることになる。書き
込まれた磁気パターンから再生信号ヘッドにより、サー
ボ信号（サーボバースト信号または単にバーストとも言
う）が再生される。At this time, as shown in FIG. 9, since the magnetic flux concentrates on the soft magnetic layer pattern 5 generated on the master disk 4, the area immediately below the soft magnetic layer pattern 5 is not affected by the transfer magnetic field. , The initial magnetization is preserved as it is.
On the other hand, the magnetic layer immediately below the portion without the soft magnetic layer pattern 5 is magnetized in the direction opposite to the initial magnetization due to the influence of the magnetic flux leaking from the edge of the soft magnetic layer. As a result, a magnetic pattern corresponding to the soft magnetic layer pattern 5 on the master disk 4 is magnetically transferred to the medium 1. A servo signal (also called a servo burst signal or simply a burst) is reproduced from the written magnetic pattern by a reproduction signal head.
【０００４】以上の転写プロセスでは、メディア１とマ
スターディスク４の密着手段として真空吸着を利用して
いる。この吸着が不充分な状態のまま転写を行なうと、
磁気パターンが充分転写されず、サーボバースト信号の
振幅が図１０のように低下する。なお、密着不良の要因
としては、 １）マスターディスクまたは記録メディアに、サブミク
ロン（極微少）ないしミクロンサイズのパーティクルが
付着し、マスターディスクと記録メディアとの密着を阻
害するケース。 ２）マスターディスクと記録メディアとの真空吸着が完
了する前に、磁石が近接するケース。 などが考えられ、要因によっても密着不良の程度が異な
る。例えば、サブミクロンサイズパーティクルの場合
は、ミクロンサイズパーティクルに比べて密着不良の程
度は軽微である。[0004] In the above transfer process, vacuum suction is used as a means for adhering the medium 1 and the master disk 4. If transfer is performed while this adsorption is insufficient,
The magnetic pattern is not sufficiently transferred, and the amplitude of the servo burst signal decreases as shown in FIG. The causes of the poor adhesion are as follows: 1) A case where submicron (micro) particles or micron-sized particles adhere to the master disk or the recording medium and hinder the adhesion between the master disk and the recording medium. 2) A case in which a magnet approaches before vacuum suction between the master disk and the recording medium is completed. And the like, and the degree of poor adhesion varies depending on the factors. For example, in the case of submicron sized particles, the degree of poor adhesion is smaller than that of micron sized particles.
【０００５】[0005]
【発明が解決しようとする課題】このように、メディア
とマスターディスクとの吸着が不充分な状態のまま転写
を行なうと、メディアの記録層は飽和磁化に到達せず、
サーボ信号パターンを充分に書きこむことができない
が、密着不良の程度が分かれば、その要因を解明する手
だてとして有用となる。したがって、この発明の課題
は、書き込まれたサーボ信号を用いて密着不良の程度を
簡単に検出できるようにし、信頼性を向上させることに
ある。As described above, if the transfer is performed while the adsorption between the medium and the master disk is insufficient, the recording layer of the medium does not reach the saturation magnetization,
Although the servo signal pattern cannot be sufficiently written, if the degree of the adhesion failure is known, it becomes useful as a means for elucidating the cause. Therefore, an object of the present invention is to make it possible to easily detect the degree of adhesion failure using a written servo signal and to improve reliability.
【０００６】[0006]
【課題を解決するための手段】このような課題を解決す
るため、請求項１の発明では、表面に軟磁性層からなる
サーボパターンを有するマスターディスクと、予め一方
向に初期磁化された記録メディアとを、前記マスターデ
ィスクの軟磁性層パターンと記録メディアの磁性層とが
相対するように密着させ、マスターディスク上方から初
期磁化と逆向きの磁界をかけて記録メディアにサーボ信
号を書き込むに当たり、前記マスターディスクから記録
メディアに書き込むサーボ信号の一部に、サーボ信号と
は異なる周波数の信号を含めて書き込みを行ない、書き
込まれた各周波数信号の平均振幅に基づき密着の程度を
判断することを特徴とする。この請求項１の発明では、
前記周波数信号の高周波部分の平均振幅が減少し、低周
波部分の平均振幅が減少しないときは軽微な密着不良と
判断し、低周波から高周波まで平均振幅が減少するとき
は重度の密着不良と判断することができる（請求項２の
発明）。In order to solve such a problem, according to the first aspect of the present invention, there is provided a master disk having a servo pattern formed of a soft magnetic layer on a surface thereof, and a recording medium which is initially magnetized in one direction in advance. Are brought into close contact with each other so that the soft magnetic layer pattern of the master disk and the magnetic layer of the recording medium are opposed to each other, and when writing a servo signal to the recording medium by applying a magnetic field opposite to the initial magnetization from above the master disk, A part of the servo signal to be written from the master disk to the recording medium is written including a signal with a frequency different from the servo signal, and the degree of adhesion is determined based on the average amplitude of each written frequency signal. I do. In the invention of claim 1,
When the average amplitude of the high-frequency portion of the frequency signal decreases and the average amplitude of the low-frequency portion does not decrease, it is determined that the adhesion is slight, and when the average amplitude decreases from low to high frequencies, it is determined that the adhesion is severe. (The invention of claim 2).
【０００７】請求項３の発明では、表面に軟磁性層から
なるサーボパターンを有するマスターディスクと、予め
一方向に初期磁化された記録メディアとを、前記マスタ
ーディスクの軟磁性層パターンと記録メディアの磁性層
とが相対するように密着させ、マスターディスク上方か
ら初期磁化と逆向きの磁界をかけて記録メディアにサー
ボ信号を書き込むに当たり、前記マスターディスクから
記録メディアに書き込むサーボ信号の一部に、サーボ信
号とは異なる周波数の信号を含めて書き込みを行ない、
書き込まれた各周波数信号のＦＦＴ解析を行ない、各周
波数信号のパワースペクトラムに基づき密着の程度を判
断することを特徴とする。この請求項３の発明では、前
記周波数信号の高周波部のパワースペクトラムが減少
し、低周波部のパワースペクトラムが減少しないときは
軽微な密着不良と判断し、低周波数から高周波数までパ
ワースペクトラムが減少するときは重度の密着不良と判
断することができる（請求項４の発明）。According to a third aspect of the present invention, a master disk having a servo pattern formed of a soft magnetic layer on the surface thereof, and a recording medium preliminarily magnetized in one direction are combined with the soft magnetic layer pattern of the master disk and the recording medium. When writing a servo signal to a recording medium by applying a magnetic field in the direction opposite to the initial magnetization from above the master disk, a part of the servo signal to be written from the master disk to the recording medium includes a servo layer. Write including the signal of the frequency different from the signal,
The FFT analysis of each written frequency signal is performed, and the degree of adhesion is determined based on the power spectrum of each frequency signal. According to the third aspect of the present invention, when the power spectrum of the high frequency part of the frequency signal decreases and the power spectrum of the low frequency part does not decrease, it is determined that the adhesion is slight, and the power spectrum decreases from the low frequency to the high frequency. If so, it can be determined that the adhesion is severely poor (the invention of claim 4).
【０００８】[0008]
【発明の実施の形態】図１はこの発明の実施の形態を説
明するための説明図である。これは、マスターディスク
４に形成される軟磁性層パターン例を示し、従来のサー
ボ信号に対応する波長の短いパターン１０と、その約２
倍の波長のパターン１１を形成した例である。なお、従
来のサーボ信号に対応する波長の短いパターンに対し、
これより波長の短いパターンを形成するようにしても良
い。図２はこの発明による転写態様説明図である。同図
からも明らかなように、波長の長いパターン１１の方
が、波長の短いパターン１０に比べて、長手方向の磁束
がメディア１の深い位置まで到達することがわかる。つ
まり、密着不良発生時には、マスターディスク４と記録
メディア１の磁性層２との距離は正常密着時より開いて
いるが、波長の短いパターン１０の直下の磁性層に比
べ、波長の長いパターン１１の直下の磁性層の方が磁化
させ易いことになる。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory diagram for explaining an embodiment of the present invention. This shows an example of a soft magnetic layer pattern formed on the master disk 4, in which a short-wavelength pattern 10 corresponding to a conventional servo signal and its approximately 2
This is an example in which a double wavelength pattern 11 is formed. For short-wavelength patterns corresponding to conventional servo signals,
A pattern having a shorter wavelength may be formed. FIG. 2 is an explanatory view of a transfer mode according to the present invention. As can be seen from the drawing, it is understood that the magnetic flux in the longitudinal direction reaches the deep position of the medium 1 in the long wavelength pattern 11 as compared with the short wavelength pattern 10. That is, when poor adhesion occurs, the distance between the master disk 4 and the magnetic layer 2 of the recording medium 1 is wider than in normal adhesion, but the pattern 11 having a longer wavelength is compared with the magnetic layer immediately below the pattern 10 having a shorter wavelength. The magnetic layer immediately below is easier to magnetize.
【０００９】図３はこの発明による第１の密着不良検出
方法を示すフローチャートである。これは、以上のよう
に波長の短いパターン１０で書き込まれたバースト信号
Ａと、波長の長いパターン１１で書き込まれたバースト
信号Ｂを、記録メディア１から読み出して信号Ａの平均
振幅ＶAと、信号Ｂの平均振幅ＶBとを検出し（，参
照）、その各々をしきい値と比較して両方ともしきい値
以上のときは正常（，参照）、ＶAのみがしきい値
以下のときは軽微な密着不良（，参照）、両方とも
しきい値以下のときは重度の密着不良（，参照）と
判断するものである。FIG. 3 is a flow chart showing a first method of detecting poor adhesion according to the present invention. This is because, as described above, the burst signal A written with the short-wavelength pattern 10 and the burst signal B written with the long-wavelength pattern 11 are read from the recording medium 1 and the average amplitude VA of the signal A is obtained. detecting an average amplitude V B of the signal B (see), normal when the above both by comparing each of the threshold threshold (see), only V a is below the threshold In this case, it is determined that the adhesion is slight (refer to reference), and when both are lower than the threshold value, it is determined that the adhesion is severe (see reference).
【００１０】図４はこの発明による密着不良時（軽微）
の転写態様説明図、図５はこの発明による密着不良時
（重度）の転写態様説明図である。すなわち、図４では
波長の短い部分で磁化状態が不良となっていて、バース
ト信号Ａのレベルが低下している状態（軽微な密着不良
状態）が示されており、図５では波長の短い部分，長い
部分とも磁化状態は不良となっていて、バースト信号
Ａ，Ｂのレベルがともに低下している状態（重度の密着
不良状態）が示されている。FIG. 4 shows a state of poor adhesion (slight) according to the present invention.
FIG. 5 is an explanatory view of a transfer mode at the time of poor adhesion (severe) according to the present invention. That is, FIG. 4 shows a state in which the magnetization state is defective in a short wavelength portion and the level of the burst signal A is reduced (a slight adhesion failure state), and FIG. 5 shows a short wavelength portion. , The magnetized state is defective in all the long parts, and the state where both the levels of the burst signals A and B are lowered (a state of severe adhesion failure) is shown.
【００１１】図６はこの発明による第２の密着不良検出
方法を示すフローチャートである。図３ではサーボ信号
の平均振幅に着目したが、ここでは書き込まれたサーボ
信号Ａ，ＢのＦＦＴ（高速フーリエ変換）解析を行な
い、サーボ信号Ａのスペクトラム（周波数毎の強度）Ｓ
Aと、サーボ信号Ｂのスペクトラム（周波数毎の強度）
ＳBとを求め、その各々をしきい値と比較して両方とも
しきい値以上のときは正常（，参照）、ＳAのみが
しきい値以下のときは軽微な密着不良（，参照）、
両方ともしきい値以下のときは重度の密着不良（，
参照）と判断するものである。なお、ＦＦＴ技術は良く
知られているので、詳細は省略する。FIG. 6 is a flow chart showing a second method for detecting poor adhesion according to the present invention. Although FIG. 3 focuses on the average amplitude of the servo signal, here, FFT (Fast Fourier Transform) analysis of the written servo signals A and B is performed, and the spectrum (intensity for each frequency) S of the servo signal A is calculated.
A and spectrum of servo signal B (intensity for each frequency)
Seeking and S B, normal when the above both by comparing each of the threshold threshold (see), the minor adhesion failure when only S A is less than the threshold value (see) ,
If both are below the threshold, severe poor adhesion (,
Reference). Since the FFT technique is well known, the details are omitted.
【００１２】[0012]
【発明の効果】この発明によれば、磁気ディスクに書き
込まれたサーボ信号から、密着不良の程度を簡単に判断
することができ、密着転写方式の信頼性を高めることが
可能となる利点が得られる。According to the present invention, the degree of adhesion failure can be easily determined from the servo signal written on the magnetic disk, and the advantage that the reliability of the adhesion transfer method can be improved can be obtained. Can be
【図１】この発明の実施の形態を説明するための説明図
である。FIG. 1 is an explanatory diagram for describing an embodiment of the present invention.
【図２】この発明による密着正常時の転写態様説明図で
ある。FIG. 2 is an explanatory view of a transfer mode at the time of normal contact according to the present invention.
【図３】この発明による第１の密着不良検出方法を示す
フローチャートである。FIG. 3 is a flowchart showing a first adhesion failure detection method according to the present invention.
【図４】この発明による密着不良時（軽微）の転写態様
説明図である。FIG. 4 is an explanatory view of a transfer mode at the time of poor adhesion (slight) according to the present invention.
【図５】この発明による密着不良時（重度）の転写態様
説明図である。FIG. 5 is an explanatory view of a transfer mode at the time of poor adhesion (severe) according to the present invention.
【図６】この発明による第２の密着不良検出方法を示す
フローチャートである。FIG. 6 is a flowchart showing a second adhesion failure detection method according to the present invention.
【図７】従来のサーボライト方式の初期磁化方法説明図
である。FIG. 7 is an explanatory diagram of an initial magnetization method of a conventional servo write method.
【図８】従来のサーボライト方式の転写方法説明図であ
る。FIG. 8 is an explanatory view of a conventional servo write type transfer method.
【図９】従来のサーボライト方式の密着正常時の転写方
法説明図である。FIG. 9 is an explanatory view of a transfer method of the conventional servo write method when the contact is normal.
【図１０】従来のサーボライト方式の密着不良時の転写
方法説明図である。FIG. 10 is an explanatory view of a transfer method at the time of adhesion failure in a conventional servo write system.
１…記録メディア（磁気ディスク）、２…磁性層、３Ａ
…初期化用磁石、３Ｂ…転写用磁石、４…マスターディ
スク、５…軟磁性膜パターン、１０…波長の短い軟磁性
膜パターン、１１…波長の長い軟磁性膜パターン。DESCRIPTION OF SYMBOLS 1 ... Recording medium (magnetic disk), 2 ... Magnetic layer, 3A
... Initializing magnet, 3B Transfer magnet, 4 Master disk, 5 Soft magnetic film pattern, 10 Soft magnetic film pattern with short wavelength, 11 Soft magnetic film pattern with long wavelength.
Claims (4)
を有するマスターディスクと、予め一方向に初期磁化さ
れた記録メディアとを、前記マスターディスクの軟磁性
層パターンと記録メディアの磁性層とが相対するように
密着させ、マスターディスク上方から初期磁化と逆向き
の磁界をかけて記録メディアにサーボ信号を書き込むに
当たり、 前記マスターディスクから記録メディアに書き込むサー
ボ信号の一部に、サーボ信号とは異なる周波数の信号を
含めて書き込みを行ない、書き込まれた各周波数信号の
平均振幅に基づき密着の程度を判断することを特徴とす
る磁気ディスク試験方法。1. A master disk having a servo pattern composed of a soft magnetic layer on its surface, and a recording medium which has been initially magnetized in one direction in advance, are compared with a soft magnetic layer pattern of the master disk and a magnetic layer of the recording medium. When writing a servo signal on the recording medium by applying a magnetic field in the direction opposite to the initial magnetization from above the master disk, a part of the servo signal written from the master disk to the recording medium has a frequency different from that of the servo signal. A magnetic disk test method, wherein writing is performed including the above signal, and the degree of adhesion is determined based on the average amplitude of each written frequency signal.
が減少し、低周波部分の平均振幅が減少しないときは軽
微な密着不良と判断し、低周波から高周波まで平均振幅
が減少するときは重度の密着不良と判断することを特徴
とする請求項１に記載の磁気ディスク試験方法。2. When the average amplitude of the high-frequency portion of the frequency signal decreases and the average amplitude of the low-frequency portion does not decrease, it is determined that the adhesion is slight, and when the average amplitude decreases from low frequency to high frequency, it is severe. 2. The magnetic disk test method according to claim 1, wherein it is determined that the adhesion is poor.
を有するマスターディスクと、予め一方向に初期磁化さ
れた記録メディアとを、前記マスターディスクの軟磁性
層パターンと記録メディアの磁性層とが相対するように
密着させ、マスターディスク上方から初期磁化と逆向き
の磁界をかけて記録メディアにサーボ信号を書き込むに
当たり、 前記マスターディスクから記録メディアに書き込むサー
ボ信号の一部に、サーボ信号とは異なる周波数の信号を
含めて書き込みを行ない、書き込まれた各周波数信号の
ＦＦＴ解析を行ない、各周波数信号のパワースペクトラ
ムに基づき密着の程度を判断することを特徴とする磁気
ディスク試験方法。3. A master disk having a servo pattern composed of a soft magnetic layer on the surface thereof, and a recording medium which has been initially magnetized in one direction in advance, are compared with the soft magnetic layer pattern of the master disk and the magnetic layer of the recording medium. When writing a servo signal on the recording medium by applying a magnetic field in the direction opposite to the initial magnetization from above the master disk, a part of the servo signal written from the master disk to the recording medium has a frequency different from that of the servo signal. A magnetic disk test method, wherein writing is performed including the above signals, FFT analysis is performed on each written frequency signal, and the degree of adhesion is determined based on the power spectrum of each frequency signal.
クトラムが減少し、低周波部のパワースペクトラムが減
少しないときは軽微な密着不良と判断し、低周波数から
高周波数までパワースペクトラムが減少するときは重度
の密着不良と判断することを特徴とする請求項３に記載
の磁気ディスク試験方法。4. When the power spectrum of the high-frequency part of the frequency signal decreases and the power spectrum of the low-frequency part does not decrease, it is determined that the adhesion is slight, and when the power spectrum decreases from the low frequency to the high frequency, 4. The magnetic disk test method according to claim 3, wherein it is determined that the adhesion is severe.
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| JP2000103174A JP4117519B2 (en) | 2000-04-05 | 2000-04-05 | Magnetic disk test method |
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| JP2000103174A JP4117519B2 (en) | 2000-04-05 | 2000-04-05 | Magnetic disk test method |
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| JP4117519B2 JP4117519B2 (en) | 2008-07-16 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1492090A1 (en) * | 2003-06-26 | 2004-12-29 | Fuji Photo Film Co., Ltd. | Patterned master carrier for magnetic transfer, manufacturing method thereof, magnetic transfer method, recording medium, and magnetic recording and reproduction apparatus |
| EP1580733A3 (en) * | 2004-03-24 | 2006-01-04 | Fuji Photo Film Co., Ltd. | Master information carrier for magnetic transfer, magnetic transfer method, and magnetic recording medium |
-
2000
- 2000-04-05 JP JP2000103174A patent/JP4117519B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1492090A1 (en) * | 2003-06-26 | 2004-12-29 | Fuji Photo Film Co., Ltd. | Patterned master carrier for magnetic transfer, manufacturing method thereof, magnetic transfer method, recording medium, and magnetic recording and reproduction apparatus |
| EP1580733A3 (en) * | 2004-03-24 | 2006-01-04 | Fuji Photo Film Co., Ltd. | Master information carrier for magnetic transfer, magnetic transfer method, and magnetic recording medium |
| US7385774B2 (en) | 2004-03-24 | 2008-06-10 | Fujifilm Corporation | Master information carrier for magnetic transfer, magnetic transfer method, and magnetic recording medium |
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| Publication number | Publication date |
|---|---|
| JP4117519B2 (en) | 2008-07-16 |
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