JPH04159608A - Magnetic recorder - Google Patents

Magnetic recorder

Info

Publication number
JPH04159608A
JPH04159608A JP28493490A JP28493490A JPH04159608A JP H04159608 A JPH04159608 A JP H04159608A JP 28493490 A JP28493490 A JP 28493490A JP 28493490 A JP28493490 A JP 28493490A JP H04159608 A JPH04159608 A JP H04159608A
Authority
JP
Japan
Prior art keywords
signal
output
servo
frequency
comparator
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
JP28493490A
Other languages
Japanese (ja)
Inventor
Atsushi Hirano
敦士 平野
Hiroyuki Aoki
弘幸 青木
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 Gunma Ltd
Original Assignee
NEC Gunma 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 NEC Gunma Ltd filed Critical NEC Gunma Ltd
Priority to JP28493490A priority Critical patent/JPH04159608A/en
Publication of JPH04159608A publication Critical patent/JPH04159608A/en
Pending legal-status Critical Current

Links

Landscapes

  • Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)

Abstract

PURPOSE:To obtain the output wherein only a servo signal is separated by performing the subtraction of the digital output of a data signal which does not include a servo-signal component and the analog output wherein the servo signal and the data signal are superimposed in a comparator. CONSTITUTION:A servo signal at a low frequency and a data signal having the spectrum in the vicinity of the servo-signal frequency are regenerated with a magnetic head 1 and inputted into a read amplifier 2. The servo signal is removed from one of the outputs of the amplifier 2 with a comparator 4, and a digital output 14 having only the frequency spectrum of the data signal is obtained. The other output of the amplifier 2 becomes an analog output 13 wherein frequency spectrums of the servo signal and the data signal are superimposed. The two outputs undergo subtraction in a comparator 10. Thus, the output wherein the low-frequency noise component from the data signal is removed and only the servo signal is separated can be obtained.

Description

【発明の詳細な説明】 [産業上の利用分野コ 本発明は磁気記録装置に関し、特に深層サーボ方式(E
mbedded  5ervo)を用いる磁気記録装置
に関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording device, particularly a deep servo system (E
The present invention relates to a magnetic recording device using a magnetic recording medium (MBEDED 5ERVO).

[従来の技術] 昨今の磁気記録装置の小型、大容量化に伴って、フロッ
ピーディスク装置などのデータ面サーボ方式を用いる装
置においては、フォーマット効率。
[Prior Art] As magnetic recording devices have become smaller and have larger capacities in recent years, formatting efficiency has become increasingly important in devices that use a data surface servo method, such as floppy disk devices.

トラッキングなどで有利な深層サーボ方式の採用が検討
されている。
The adoption of a deep servo system, which is advantageous for tracking, etc., is being considered.

従来、深層サーボ方式においては、サーボ信号の周波数
をデータ信号周波数に対して充分に低く設定し、各々の
信号の干渉がないようにしている。
Conventionally, in the deep servo system, the frequency of the servo signal is set sufficiently lower than the data signal frequency to prevent interference between the respective signals.

しかしながら、例えば第4図に示す8ビツトデータパタ
ーン35のような信号が繰り返し記録されている場合、
信号再生時の周波数成分には、MFM方式の低記録周波
数(1f)の4倍の波長をもつスペクトルが、深層のサ
ーボ信号再生出力に匹敵する大きさで観測される。この
現象は、数ピットル数十ビットの繰り返しデータパター
ンが再生されるときにもみられ、その周波数成分は、は
ぼ連続しており、大きさもサーボ特性に影響を及ぼす恐
れがある程である。
However, if a signal such as the 8-bit data pattern 35 shown in FIG. 4 is repeatedly recorded,
In the frequency components during signal reproduction, a spectrum with a wavelength four times the low recording frequency (1f) of the MFM system is observed with a magnitude comparable to the deep servo signal reproduction output. This phenomenon is also observed when a repeating data pattern of several pits and several tens of bits is reproduced, and its frequency components are nearly continuous, and the magnitude thereof may be such that it may affect the servo characteristics.

この繰り返しデータパターンによる低周波成分と、サー
ボ信号との干渉を充分さけうる方法は考案されておらず
、サーボ精度の悪化などを余儀なくされていた。
No method has been devised to sufficiently avoid the interference between the low frequency components caused by this repetitive data pattern and the servo signal, resulting in deterioration of servo accuracy.

[発明が解決しようとする課題] 上述した従来の深層サーボ方式は、書込まれているデー
タパターンによって、サーボ信号出力に変動が発生し、
それによりトラッキングのばらつきなどのオフトラック
が生じていた。
[Problems to be Solved by the Invention] In the conventional deep servo method described above, variations occur in the servo signal output depending on the written data pattern.
This caused off-track errors such as tracking variations.

また、干渉の発生しにくい周波数や、変調方式を選定し
なければならず、設計時の自由度が奪われるなど、多く
の欠点があった。
In addition, there were many drawbacks, such as the need to select frequencies and modulation methods that are unlikely to cause interference, which deprived the degree of freedom in design.

[課題を解決するための手段] 本発明は、深層サーボ方式を用いる磁気記録装置におい
て、アナログ信号出力とデジタル信号出力との間に比較
演算器を具備することを特徴とするものである。
[Means for Solving the Problems] The present invention is a magnetic recording device using a deep servo system, which is characterized in that a comparator is provided between an analog signal output and a digital signal output.

[実施例コ 次に本発明について図面を参照して説明する。[Example code] Next, the present invention will be explained with reference to the drawings.

第1図は本発明の一実施例のブロック図である。FIG. 1 is a block diagram of one embodiment of the present invention.

磁気ヘッド1により、低周波のサーボ信号と、サーボ信
号周波数近傍のスペクトルをもつデータ信号が再生され
、リードアンプ2に入力される。
A low-frequency servo signal and a data signal having a spectrum near the servo signal frequency are reproduced by the magnetic head 1 and input to the read amplifier 2.

それは通常の経路として微分器3.コンパレータ4を通
ってデジタル信号に復調されるが、それをさらに172
分周器8を通してその周波数成分を、リードアンプ出力
11と同じ内容にもどしておく。
It is the normal path to differentiator 3. It passes through comparator 4 and is demodulated into a digital signal, which is then further demodulated into 172
The frequency component is returned to the same content as the read amplifier output 11 through the frequency divider 8.

但し、その位相は微分器3によってπ/2の遅れが生じ
ている。また、リードアンプ出力11は、別の経路とし
てサーボ信号周波数近傍のみを通すバンドパスフィルタ
5を通過し、位相差補正回路6により、位相をπ/2遅
れさせ、アンプ7を通ってアナログ系出力13として、
サーボ信号に、データ信号からの低周波ノイズ成分が重
畳した出力が得られる。
However, the phase is delayed by π/2 due to the differentiator 3. In addition, the read amplifier output 11 passes through a band pass filter 5 that passes only the vicinity of the servo signal frequency as another route, and the phase is delayed by π/2 by a phase difference correction circuit 6.The read amplifier output 11 passes through an amplifier 7 and is output as an analog system output. As 13,
An output is obtained in which a low frequency noise component from a data signal is superimposed on a servo signal.

また、デジタル系も、バンドパスフィルタ5と同様の特
性をもつバンドパスフィルタ9を通して、アナログ系出
力13と同位相の、データ信号からの低周波ノイズ成分
のみをもった出力がデジタル系出力14として得られる
。低周波数のサーボ信号はコンパレータ4を通過する際
、完全に排除されるためである。アナログ系出力13と
デジタル系出力14を比較演算器10にて減算すること
により、データ信号からの低周波ノイズ成分を排除した
サーボ信号出力15が得られる。
In addition, for the digital system, an output having only low frequency noise components from the data signal, which is in the same phase as the analog system output 13, is passed through a band pass filter 9 having the same characteristics as the band pass filter 5 as a digital system output 14. can get. This is because the low frequency servo signal is completely eliminated when passing through the comparator 4. By subtracting the analog system output 13 and the digital system output 14 in the comparator 10, a servo signal output 15 from which low frequency noise components are removed from the data signal is obtained.

第2図は本発明の第2の実施例のブロック図である。第
1図中において、アナログ系出力13を得るために、リ
ードアンプ2の出力11から信号出力を得ていたが、こ
れを微分器18の出力から得るように変更しである。こ
れにより、その中に含まれるサーボ信号成分は若干減少
するが、コンパレータ19の出力と比較して位相差がな
いので、位相差補正を行なう必要がない。
FIG. 2 is a block diagram of a second embodiment of the invention. In FIG. 1, the signal output was obtained from the output 11 of the read amplifier 2 in order to obtain the analog output 13, but this has been changed to be obtained from the output of the differentiator 18. As a result, the servo signal component contained therein is slightly reduced, but since there is no phase difference compared to the output of the comparator 19, there is no need to perform phase difference correction.

第3図は本発明の第3の実施例のブロック図である。こ
れは第1図の例と同様に、アナログ系はリードアンプ2
8の出力から、デジタル系はコンパレータ28の出力か
ら、それぞれ信号を得ている。デジタル系は1/2分周
器31を通ったあと、バンドパスフィルタ32を通り、
さらに検波平滑回路33によって、その信号成分の位相
情報をもたない電圧v2が得られる。アナログ系も同様
の処理により電圧v1が得られ、(vt −V2 )を
比較演算器34の出力とすることにより、データパター
ンの影響によりサーボ信号レベルの変動スることがない
、高精度なサーボ情報を得ることができる。
FIG. 3 is a block diagram of a third embodiment of the present invention. This is similar to the example in Figure 1, and the analog system uses lead amplifier 2.
The digital system obtains signals from the output of the comparator 8 and the output of the comparator 28, respectively. After the digital system passes through a 1/2 frequency divider 31, it passes through a band pass filter 32,
Further, the detection smoothing circuit 33 obtains a voltage v2 that does not have phase information of the signal component. For the analog system, the voltage v1 is obtained through the same processing, and by using (vt - V2) as the output of the comparator 34, high-precision servo control is achieved without fluctuations in the servo signal level due to the influence of the data pattern. You can get information.

[発明の効果コ 以上説明したように本発明は、サーボ信号成分が排除さ
れ、データ信号の周堤数スペクトルのみをもつコンパレ
ータ出力と、サーボ信号およびデータ信号の周波数スペ
クトルが重畳して含まれるアナログ信号とを、比較演算
器にて減算することにより、記録されているデータパタ
ーンによって発生するサーボ信号周波数近傍の出力変動
によって左右されることのない、サーボ信号のみを分離
した出力を得ることができる効果を奏する。
[Effects of the Invention] As explained above, the present invention provides a comparator output in which the servo signal component is eliminated and has only the frequency spectrum of the data signal, and an analog signal in which the frequency spectra of the servo signal and the data signal are superimposed. By subtracting the servo signal from the servo signal using a comparator, it is possible to obtain an output that separates only the servo signal, which is not affected by output fluctuations near the servo signal frequency that occur due to the recorded data pattern. be effective.

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

第1図は本発明の一実施例のブロック図、第2図は本発
明の第2の実施例のブロック図、第3図は本発明の第3
の実施例のブロック図、第4図は低周波数域にスペクト
ルをもつデータパターンの例を示す図である。 1・・・磁気ヘッド、2・・・リードアンプ、3・・・
微分器、4・・・コンパレータ、5・・・バンドバスフ
ィル夕、6・・・位相差補正回路、7・・・アンプ、8
・・・1/2分周器、9・・・バンドパスフィルタ、1
0・・・比較演算器、11・・・リードアンプ出力、1
2・・・コンパレータ出力、13・・・アナログ系出力
、14・・・デジタル系出力、15・・・サーボ信号出
力、16・・・磁気ヘッド17・・・リードアンプ、1
8・・・微分器、19・・・コンパレータ、20・・・
バンドパスフィルタ、21・・・アンプ、22・・・1
72分周器、2−3・・・バンドパスフィルタ、24・
・・比較演算器、25・・・磁気ヘッド、26・・・リ
ードアンプ、27・・・27.28・・・フンパレータ
、29・・・バンドパスフィルタ、30・・・検波平滑
回路、31・・・1/2分周器、32・・・バンドパス
フィルタ、33・・・検波平滑回路、34・・・比較演
算器、35・・・8ビツトデータパターン。
FIG. 1 is a block diagram of one embodiment of the present invention, FIG. 2 is a block diagram of a second embodiment of the present invention, and FIG. 3 is a block diagram of a third embodiment of the present invention.
FIG. 4 is a block diagram of an embodiment of the present invention, and is a diagram showing an example of a data pattern having a spectrum in a low frequency range. 1...Magnetic head, 2...Read amplifier, 3...
Differentiator, 4... Comparator, 5... Bandpass filter, 6... Phase difference correction circuit, 7... Amplifier, 8
...1/2 frequency divider, 9...Band pass filter, 1
0... Comparison calculator, 11... Read amplifier output, 1
2... Comparator output, 13... Analog system output, 14... Digital system output, 15... Servo signal output, 16... Magnetic head 17... Read amplifier, 1
8... Differentiator, 19... Comparator, 20...
Bandpass filter, 21...Amplifier, 22...1
72 Frequency divider, 2-3...Band pass filter, 24.
...Comparison calculator, 25...Magnetic head, 26...Read amplifier, 27...27.28...Hunperator, 29...Band pass filter, 30...Detection smoothing circuit, 31... ... 1/2 frequency divider, 32... Band pass filter, 33... Detection smoothing circuit, 34... Comparison calculator, 35... 8-bit data pattern.

Claims (1)

【特許請求の範囲】[Claims] 深層サーボ方式を用いる磁気記録装置において、アナロ
グ信号出力とデジタル信号出力との間に比較演算器を具
備することを特徴とする磁気記録装置。
What is claimed is: 1. A magnetic recording device using a deep servo system, characterized in that the magnetic recording device is equipped with a comparator between an analog signal output and a digital signal output.
JP28493490A 1990-10-23 1990-10-23 Magnetic recorder Pending JPH04159608A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP28493490A JPH04159608A (en) 1990-10-23 1990-10-23 Magnetic recorder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP28493490A JPH04159608A (en) 1990-10-23 1990-10-23 Magnetic recorder

Publications (1)

Publication Number Publication Date
JPH04159608A true JPH04159608A (en) 1992-06-02

Family

ID=17684955

Family Applications (1)

Application Number Title Priority Date Filing Date
JP28493490A Pending JPH04159608A (en) 1990-10-23 1990-10-23 Magnetic recorder

Country Status (1)

Country Link
JP (1) JPH04159608A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5914830A (en) * 1990-09-18 1999-06-22 Rodime Plc Digital servo control system including sample integrity tester for reducing effects of spurious sampled position values

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5914830A (en) * 1990-09-18 1999-06-22 Rodime Plc Digital servo control system including sample integrity tester for reducing effects of spurious sampled position values

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