JPH01251413A - Magnetic disk device - Google Patents
Magnetic disk deviceInfo
- Publication number
- JPH01251413A JPH01251413A JP7955288A JP7955288A JPH01251413A JP H01251413 A JPH01251413 A JP H01251413A JP 7955288 A JP7955288 A JP 7955288A JP 7955288 A JP7955288 A JP 7955288A JP H01251413 A JPH01251413 A JP H01251413A
- Authority
- JP
- Japan
- Prior art keywords
- head
- recording
- magnetic head
- magnetic
- magneto
- 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
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 69
- 230000001939 inductive effect Effects 0.000 abstract description 17
- 101000606504 Drosophila melanogaster Tyrosine-protein kinase-like otk Proteins 0.000 abstract description 12
- 230000000694 effects Effects 0.000 abstract description 7
- 229910000889 permalloy Inorganic materials 0.000 abstract description 3
- 238000010586 diagram Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
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
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
- G11B5/55—Track change, selection or acquisition by displacement of the head
- G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
- G11B5/5526—Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof
- G11B5/553—Details
-
- 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
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/596—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
- G11B5/59683—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks for magnetoresistive heads
-
- 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
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
- G11B5/3967—Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read
Landscapes
- Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
Abstract
Description
【発明の詳細な説明】
Ａ産業上の利用分野
本発明は磁気ディスク装置に関し、特にデータ記録用の
磁気ヘッドに加えて再生用の磁気ヘッドを備えた磁気デ
ィスク装置に適用して好適なものである。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a magnetic disk device, and is particularly suitable for application to a magnetic disk device equipped with a magnetic head for data reproduction in addition to a magnetic head for data recording. be.
Ｂ発明の概要
本発明は、磁気ディスク装置において、ヘッド幅の大き
な磁気ヘッドを用いてトラッキング制御することにより
、記録再生用ヘッドを高い精度でトラッキング制御する
ことができる。B. Summary of the Invention The present invention enables highly accurate tracking control of a recording/reproducing head in a magnetic disk device by performing tracking control using a magnetic head with a large head width.
Ｃ従来の技術
従来、この種の磁気ディスク装置においては、磁気抵抗
効果を利用した磁気ヘッド（以下磁気抵抗効果型の磁気
ヘッドと呼ぶ）と、通常のコイル及び磁気回路を用いた
磁気ヘッド（以下インダクテイブ型の磁気ヘッドと呼ぶ
）とを組み合わせた１組の記録再生用ヘッドを用いて、
データを記録及び再生するするようになされたものがあ
る（特公昭５９−３５０８８号公報）。C. Conventional technology Conventionally, in this type of magnetic disk drive, there are two types: a magnetic head that utilizes the magnetoresistive effect (hereinafter referred to as a magnetoresistive magnetic head), and a magnetic head that uses an ordinary coil and magnetic circuit (hereinafter referred to as a magnetoresistive magnetic head). Using a set of recording and reproducing heads combined with an inductive type magnetic head,
There is a device designed to record and reproduce data (Japanese Patent Publication No. 59-35088).
すなわち第１図及び第２図は、それぞれ薄膜型の記録再
生用ヘッド１の平面図及び断面図を示し、磁気抵抗効果
素子３が、記録媒体２に対抗する端面側に、パーマロイ
でなるシールド４及び５の間に挟まれて配置されている
。That is, FIGS. 1 and 2 respectively show a plan view and a cross-sectional view of a thin film type recording/reproducing head 1, in which a magnetoresistive element 3 has a shield 4 made of permalloy on its end surface facing the recording medium 2. and 5.
さらにシールド５は、パーマロイでなるシールドルアと
共にコイル８を囲むように配置され、これにより記録媒
体２に対抗する端面側に、開口部を備えた磁気回路を構
成するようになされている。Further, the shield 5 is arranged to surround the coil 8 together with a shield lure made of permalloy, thereby forming a magnetic circuit having an opening on the end face side facing the recording medium 2.
従って、当該コイル８に記録電流を流せば、当該開口部
を介して漏洩磁束が得られ、これにより記録媒体２に所
望のデータを記録することができる。Therefore, when a recording current is passed through the coil 8, leakage magnetic flux is obtained through the opening, thereby allowing desired data to be recorded on the recording medium 2.
これに対して、磁気抵抗効果素子３の磁気抵抗の変化を
検出すれば、記録媒体２に記録されたデータを再生する
ことができる。On the other hand, if a change in the magnetoresistance of the magnetoresistive element 3 is detected, data recorded on the recording medium 2 can be reproduced.
かくして、シールド５．７及びコイル８は、インダクテ
イブ型で記録専用の第１の磁気ヘッドを構成するのに対
し、磁気抵抗効果素子３及びシールド４．５は、磁気抵
抗効果型で再生専用の第２の磁気ヘッドを構成する。Thus, the shield 5.7 and the coil 8 constitute the first inductive magnetic head for recording only, whereas the magnetoresistive element 3 and the shield 4.5 constitute the first magnetic head of the magnetoresistive type for reproduction only. 2 magnetic heads are constructed.
ところで磁気抵抗効果型の磁気ヘッドは、データを記録
することが困難な代わりに、インダクテイブ型の磁気ヘ
ッドに比して、信号レベルの大きな再生出力（インダク
テイプ型の磁気ヘッドに比して約２倍）を得ることがで
き、再生専用の磁気ヘッドとして用いる場合は、その分
ヘッド幅を小さくしても、ＳＮ比の良い再生信号を得る
ことができる。By the way, although it is difficult for magnetoresistive magnetic heads to record data, they have a reproduction output with a higher signal level than inductive magnetic heads (approximately twice that of inductive tape magnetic heads). ), and when used as a read-only magnetic head, even if the head width is reduced accordingly, a read signal with a good S/N ratio can be obtained.
従って第３図に示すように、例えばヘッド幅Ｔ８が１０
〔μｍ〕のインダクテイブ型の磁気ヘッド１０を用い
て、データ及びサーボ信号（例えば米国特許３，６９１
，５４３号に提案されているようなサーボ信号）を記録
して、トラック幅Ｔ□が約１１ 〔μｍ〕の記録トラッ
クＴＲ上にデータの記録された領域ＡＲＤ及びサーボ信
号が記録された領域ＡＲ３を形成した後、例えばヘッド
幅Ｔ、が５〔μｍ〕の磁気抵抗効果型の磁気へラド１１
で当該記録トラックＴＲ上に記録されたデータ及びサー
ボ信号を再生しても、ヘッド幅Ｔ、１が１０ 〔μｍ〕
のインダクテイブ型の磁気ヘッド１０を用いて再生した
場合とほぼ等しい信号レベルの再生出力を得ることがで
きる。Therefore, as shown in FIG. 3, for example, the head width T8 is 10
[μm] inductive type magnetic head 10 is used to generate data and servo signals (for example, U.S. Pat. No. 3,691
, 543), an area ARD where data is recorded and an area AR3 where the servo signal is recorded on a recording track TR having a track width T□ of about 11 [μm]. After forming, for example, a magnetoresistance effect type magnetic helad 11 with a head width T of 5 [μm] is formed.
Even if the data and servo signals recorded on the recording track TR are reproduced, the head width T,1 is 10 [μm].
It is possible to obtain a reproduced output with approximately the same signal level as when reproduced using the inductive type magnetic head 10.
この場合、インダクテイブ型の磁気ヘッド１０に比して
磁気抵抗効果型の磁気へラド１１のベツド幅Ｔ、が小さ
な値に設定されていることから、記録再生用ヘッド１が
オフトラックした場合でも、当該オフトラック量が微少
な範囲においては（この場合は、トラックセンタＴＲＣ
から３ 〔μｍ〕の範囲）、インダクテイブ型の磁気ヘ
ッド１０によって形成された記録トラックＴＲ上を、磁
気抵抗効果型の磁気へラド１１で走査することができ、
その分確実に当該記録トラックＴＲ上に記録されたデー
タを再生することができる。In this case, since the bed width T of the magnetoresistive magnetic head 11 is set to a smaller value than that of the inductive type magnetic head 10, even if the recording/reproducing head 1 goes off-track, In a range where the off-track amount is small (in this case, the track center TRC
to 3 [μm]), the recording track TR formed by the inductive magnetic head 10 can be scanned by the magnetoresistive magnetic herad 11,
Accordingly, the data recorded on the recording track TR can be reliably reproduced.
さらに、インダクテイブ型の磁気ヘッド１０を用いて、
記録トラックＴＲ上のデータをオーバーライド消去した
際に、当該記録トラックＴＲの側面に未消去部分が残っ
ている場合でも、当該記録トラックＴＲ上に新たに記録
されたデータだけを確実に再生することができる。Furthermore, using the inductive type magnetic head 10,
Even if unerased portions remain on the sides of the recording track TR when data on the recording track TR is overridden and erased, it is possible to reliably reproduce only the newly recorded data on the recording track TR. can.
従って、その分記録トラックのトラック幅を小さく設定
して、実際上２０００ Ｔ Ｐ Ｉ （ｔｒａｃｋ ｐ
ｅｒｉｎｃｈ）程度に記録トラックを高密度に形成し得
、磁気ディスク装置全体として記録密度を高くすること
ができる。Therefore, by setting the track width of the recording track smaller by that amount, the actual track width is 2000 T P I (track p I).
Accordingly, recording tracks can be formed at a high density such that the magnetic disk device as a whole can have a high recording density.
Ｄ発明が解決しようとする問題点
ところが、この種の磁気ディスク装置においては、記録
再生用ヘッド１が所定量以上オフトラックすると、トラ
ッキングエラー信号が変化しなくなるいわゆるトラッキ
ング時のダイナミックレンジが狭い問題がある。D Problems to be Solved by the Invention However, in this type of magnetic disk device, there is a problem in which the tracking error signal does not change when the recording/reproducing head 1 goes off-track by a predetermined amount or more, so-called a narrow dynamic range during tracking. be.
すなわちサーボ信号が記録された領域ＡＲ３においては
、トラックセンタＴＲＣを境にした第１及び第２のサー
ボ領域Ａ ＲＳ ＋及びＡ ＲＳ ｚに異なるサーボ信
号が記録される。That is, in the area AR3 where the servo signal is recorded, different servo signals are recorded in the first and second servo areas A RS + and A RS z with the track center TRC as a boundary.
トラッキングエラー信号は、磁気抵抗効果型の磁気へラ
ド１１が走査する際に、当該筒１及び第２のサーボ領域
ＡＲ３，及びＡＲ３２から得られるサーボ信号の信号レ
ベルの比に基づいて検出される。The tracking error signal is detected based on the signal level ratio of the servo signals obtained from the cylinder 1 and the second servo areas AR3 and AR32 when the magnetoresistive magnetic helad 11 scans.
従ってトラック幅１１ 〔μｍ〕の記録トラックＴＲに
対し、磁気抵抗効果型の磁気へラド１１のヘッド幅ＴＲ
（＝５ Ｃμｍａｌ）が小さいため、トラックセンタＴ
ＲＣから３〔μｌ〕程度以上オフトラックすると、磁気
抵抗効果型の磁気ヘッド１■が、第１又は第２のサーボ
領域Ａ ＲＳ ＋又はＡＲ８２だけを走査するようにな
り、オフトラック量が変化してもサーボ信号の比が変化
しない状態が得られる。Therefore, for a recording track TR with a track width of 11 [μm], the head width TR of the magnetoresistive type magnetic helad 11 is
(=5 Cμmal) is small, so the track center T
When off-tracking by about 3 [μl] or more from RC, the magnetoresistive magnetic head 1 begins to scan only the first or second servo area A RS + or AR82, and the amount of off-track changes. A state is obtained in which the ratio of the servo signals does not change even when
このように、オフトラック量が変化してもトラッキング
エラー信号が変化しなくなると、記録再生用ヘッド１を
所定の記録トラックＴＲ上に移動させる（すなわちシー
ク時でなる）際に、シークエラーが生じ、その分高い精
度でトラッキング制御することが困難になる問題がある
。In this way, if the tracking error signal does not change even if the off-track amount changes, a seek error will occur when the recording/reproducing head 1 is moved onto a predetermined recording track TR (that is, during seek). , there is a problem in that it becomes difficult to perform tracking control with high precision.
本発明は以上の点を考慮してなされたもので、高い精度
でトラッキング制御することができる磁気ディスク装置
を提案しようとするものである。The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a magnetic disk device that can perform tracking control with high accuracy.
Ｅ問題点を解決するための手段
かかる問題点を解決するため本発明においては、磁気抵
抗効果型の第１の磁気へラド１１と、第１の磁気へラド
１１に比してヘッド幅Ｔ８の大きな第２の磁気ヘッドｌ
Ｏとで構成された記録再生用ヘッド１を有する磁気ディ
スク装置において、第２の磁気ヘッド１０から得られる
トラッキングエラー信号に基づいて、記録再生用ヘッド
１をトラッキング制御する。E Means for Solving the Problem In order to solve this problem, in the present invention, the first magnetic helad 11 of the magnetoresistive type and the head width T8 are made smaller than the first magnetic helad 11. Large second magnetic head
In a magnetic disk device having a recording/reproducing head 1 configured with a magnetic head 1, tracking control of the recording/reproducing head 1 is performed based on a tracking error signal obtained from the second magnetic head 10.
Ｆ作用
磁気抵抗効果型の磁気へラド１１のヘッド幅Ｔ、Ｉに比
して、ヘッド幅Ｔ、１の大きなの第２の磁気ヘッド１０
から得られるサーボ信号に基づいて、記録再生用ヘッド
ｌをトラッキング制御すれば、オフトラック量が大きく
なっても、当該オフトラック量に応じて変化するトラッ
キングエラー信号を得ることができる。The second magnetic head 10 has a head width T, 1 larger than the head width T, I of the F-action magnetoresistive magnetic herad 11.
By controlling the recording/reproducing head l based on the servo signal obtained from the servo signal, it is possible to obtain a tracking error signal that changes according to the off-track amount even if the off-track amount becomes large.
Ｇ実施例 以下図面について、本発明の一実施例を詳述する。G example An embodiment of the present invention will be described in detail below with reference to the drawings.
この実施例においては、磁気抵抗効果型の磁気へラド１
１に代えてインダクテイブ型の磁気ヘッド１０から得ら
れるサーボ信号に基づいて記録再生用ヘッド１をトラッ
キング制御する。In this embodiment, a magnetoresistance effect type magnetic herad 1 is used.
1, the recording/reproducing head 1 is tracked and controlled based on a servo signal obtained from an inductive magnetic head 10.
このようにすれば、磁気抵抗効果型の磁気ヘッド１１に
比してインダクテイブ型の磁気ヘッド１０のヘッド幅Ｔ
。が大きい分、オフトラック量が大きくなっても、当該
オフトラック量に応じて変化するトラッキングエラー信
号を得ることができ、その分トラッキング時のダイナミ
ックレンジを太き（することができる。In this way, the head width T of the inductive type magnetic head 10 is greater than that of the magnetoresistive type magnetic head 11.
. Even if the amount of off-track becomes large, it is possible to obtain a tracking error signal that changes according to the amount of off-track, and the dynamic range during tracking can be widened accordingly.
従ってその分、記録再生用ヘッド１を高い精度でトラッ
キング制御することができる。Therefore, tracking control of the recording/reproducing head 1 can be performed with higher accuracy.
さらにこのように構成すれば、ヘッド幅Ｔ。が大きい分
再生信号全体に対する第１及び第２のサーボ領域Ａ Ｒ
Ｓ ＋及びＡＲ３２の境界部分から得られる再生信号の
信号レベルを低減することができる。Furthermore, with this configuration, the head width T. The first and second servo areas A R for the entire reproduced signal are large.
The signal level of the reproduced signal obtained from the boundary between S+ and AR32 can be reduced.
実際上、再生信号全体に対する当該境界部分から得られ
る再生信号の信号レベルが高くなると、サーボ信号のＣ
Ｎ比（ｃａｒｒｉｅｒ ｐｅｒ ｓｉｇｎａｌ）が劣化
する問題があり、当該再生信号の信号レベルを低減する
ことにより、記録再生用ヘッドエをさらに高い精度でト
ラッキング制御することができる。In fact, when the signal level of the reproduced signal obtained from the boundary part with respect to the entire reproduced signal increases, the C of the servo signal increases.
There is a problem that the N ratio (carrier per signal) deteriorates, and by reducing the signal level of the reproduction signal, it is possible to control the tracking of the recording and reproduction head with even higher precision.
従ってその分高密度に記録トラックを形成して、記録密
度の高い磁気ディスク装置を得ることができる。Therefore, recording tracks can be formed at a correspondingly higher density, and a magnetic disk device with a higher recording density can be obtained.
以上の構成によれば、ヘッド幅Ｔ、の大きいインダクテ
イブ型の磁気ヘッドから得られるサーボ信号に基づいて
、記録再生用ヘッド１をトラッキング制御することによ
り、トラッキング時のダイナミックレンジを大きくする
ことができ、その分高い精度でトラッキング制御するこ
とができる。According to the above configuration, the dynamic range during tracking can be increased by controlling the tracking of the recording/reproducing head 1 based on the servo signal obtained from the inductive magnetic head with a large head width T. , tracking control can be performed with higher precision.
なお上述の実施例においては、それぞれヘッド幅が１０
〔μｍ〕及び５ （μｍ〕のインダクテイブ型及び磁気
抵抗効果型の磁気ヘッドを用いた場合について述べたが
、ヘッド幅はこれに限らず、必要に応じて自由に選定す
ることができる。In the above embodiments, each head width is 10
Although the case where inductive type and magnetoresistive type magnetic heads of [μm] and 5 (μm) are used has been described, the head width is not limited to this and can be freely selected as necessary.
Ｈ発明の効果
以上のように本発明によれば、ヘッド幅の大きな磁気ヘ
ッドから得られるサーボ信号に基づいて、記録再生用ヘ
ッドをトラッキング制御することにより、オフトラック
量が大きくなっても、当該オフトラック量に応じて変化
するトラッキングエラー信号を得ることができ、記録再
生用ヘッドをその分高い精度でトラッキング制御するこ
とができる。H Effects of the Invention As described above, according to the present invention, even if the off-track amount becomes large, the tracking control of the recording/reproducing head is performed based on the servo signal obtained from the magnetic head with a large head width. A tracking error signal that changes depending on the off-track amount can be obtained, and the recording/reproducing head can be tracked with higher precision.
第１図は本発明による磁気ディスク装置の記録再生用ヘ
ッドを示す平面図、第２図はその断面図、第３図はその
動作の説明に供する路線図である。
１・・・・・・記録再生用ヘッド、３・・・・・・磁気
抵抗効果素子、４．５．７・・・・・・シールド、１０
・・・・・・インダクテイブ型の磁気ヘッド、１１・・
・・・・磁気抵抗効果型の磁気ヘッド、ＴＲ・・・・・
・記録トラック。FIG. 1 is a plan view showing a recording/reproducing head of a magnetic disk device according to the present invention, FIG. 2 is a sectional view thereof, and FIG. 3 is a route diagram for explaining its operation. 1... Recording/reproducing head, 3... Magnetoresistive element, 4.5.7... Shield, 10
...Inductive magnetic head, 11...
... Magnetoresistive magnetic head, TR...
・Record track.
Claims (1)
ヘッドに比してヘッド幅の大きな第２の磁気ヘッドとで
構成された１組の記録再生用ヘッドを有する磁気ディス
ク装置において、 上記第２の磁気ヘッドから得られるサーボ信号に基づい
て、上記記録再生用ヘッドをトラッキング制御するよう
にした ことを特徴とする磁気ディスク装置。[Claims] A set of recording/reproducing heads comprising a magnetoresistive first magnetic head and a second magnetic head having a larger head width than the first magnetic head. A magnetic disk device comprising the following: Tracking control of the recording/reproducing head is performed based on a servo signal obtained from the second magnetic head.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63079552A JP2812949B2 (en) | 1988-03-31 | 1988-03-31 | Magnetic disk device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63079552A JP2812949B2 (en) | 1988-03-31 | 1988-03-31 | Magnetic disk device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01251413A true JPH01251413A (en) | 1989-10-06 |
| JP2812949B2 JP2812949B2 (en) | 1998-10-22 |
Family
ID=13693173
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63079552A Expired - Fee Related JP2812949B2 (en) | 1988-03-31 | 1988-03-31 | Magnetic disk device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2812949B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06314419A (en) * | 1993-04-28 | 1994-11-08 | Nec Corp | Method and device for driving head for magnetic disk |
| JPH07121805A (en) * | 1993-10-19 | 1995-05-12 | Nec Corp | Magnetic recording and reproducing method and device therefor |
| WO1996042081A1 (en) * | 1995-06-08 | 1996-12-27 | International Business Machines Corporation | Disk apparatus and servo-pattern write system |
| US6104562A (en) * | 1997-04-03 | 2000-08-15 | International Business Machines Corporation | Multiple element transducer for magnetic recording |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5935088A (en) * | 1982-08-19 | 1984-02-25 | Toshiba Corp | Device for crystal growth |
| JPS61202316A (en) * | 1985-03-04 | 1986-09-08 | Nec Corp | Thin film magnetic head for buried servo system |
-
1988
- 1988-03-31 JP JP63079552A patent/JP2812949B2/en not_active Expired - Fee Related
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5935088A (en) * | 1982-08-19 | 1984-02-25 | Toshiba Corp | Device for crystal growth |
| JPS61202316A (en) * | 1985-03-04 | 1986-09-08 | Nec Corp | Thin film magnetic head for buried servo system |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH06314419A (en) * | 1993-04-28 | 1994-11-08 | Nec Corp | Method and device for driving head for magnetic disk |
| JPH07121805A (en) * | 1993-10-19 | 1995-05-12 | Nec Corp | Magnetic recording and reproducing method and device therefor |
| WO1996042081A1 (en) * | 1995-06-08 | 1996-12-27 | International Business Machines Corporation | Disk apparatus and servo-pattern write system |
| US6104562A (en) * | 1997-04-03 | 2000-08-15 | International Business Machines Corporation | Multiple element transducer for magnetic recording |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2812949B2 (en) | 1998-10-22 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |