JPS6325405B2 - - Google Patents
Info
- Publication number
- JPS6325405B2 JPS6325405B2 JP57183217A JP18321782A JPS6325405B2 JP S6325405 B2 JPS6325405 B2 JP S6325405B2 JP 57183217 A JP57183217 A JP 57183217A JP 18321782 A JP18321782 A JP 18321782A JP S6325405 B2 JPS6325405 B2 JP S6325405B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- track
- magnetic layer
- pattern
- recording medium
- 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.)
- Expired
Links
- 230000004907 flux Effects 0.000 claims description 10
- 238000005530 etching Methods 0.000 claims description 4
- 238000001514 detection method Methods 0.000 claims description 2
- 229920006395 saturated elastomer Polymers 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 description 9
- 230000005415 magnetization Effects 0.000 description 8
- 239000000463 material Substances 0.000 description 6
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 4
- 238000000034 method Methods 0.000 description 4
- 239000010408 film Substances 0.000 description 3
- 230000006378 damage Effects 0.000 description 2
- 229910052759 nickel Inorganic materials 0.000 description 2
- 238000007747 plating Methods 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- 229910000990 Ni alloy Inorganic materials 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- 229910001260 Pt alloy Inorganic materials 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- -1 photoresist Chemical class 0.000 description 1
- 229920002120 photoresistant polymer Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000004528 spin coating Methods 0.000 description 1
- 230000009897 systematic effect 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
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/64—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent
- G11B5/66—Record carriers characterised by the selection of the material comprising only the magnetic material without bonding agent the record carriers consisting of several layers
Description
【発明の詳細な説明】
本発明は、磁気記録媒体に係り、特に記録トラ
ツクと磁気ヘツド間の位置誤差検出の差のサーボ
情報及びトラツクアドレスその他の識別情報が恒
久的に製造時に形成されている事を特徴とする磁
気記録媒体に関する。
磁気記録は一般に磁気ヘツドにより記録媒体上
に交互に磁化を反転させて記録するが、磁気ヘツ
ドが記録媒体上に形成する軌跡をトラツクと呼び
その巾は磁気ヘツドの巾と磁気ヘツドから漏れ出
る磁界分布に関係し、トラツクピツチはさらに磁
気ヘツドの位置決め誤差が関係する。磁気記録の
性能指標の一つである記録密度は、トラツク方向
の磁化反転密度である線密度とトラツク密度で表
わされ磁気デイスク装置では両者の比は通常10：
１程度である。現在、線密度に関しては、媒体材
料の開発、方式的な改良があつて１mm当り400〜
2000以上の磁化反転密度が達成されているが、ト
ラツク密度に関しては未だに１mm当り40本程度を
実現しているに過ぎない。したがつて、磁気記録
において高密度記録を達成する為の近道は、トラ
ツク密度を増す事であり、願わくは磁化反転密度
に出来るだけ近づける事である。しかしながらト
ラツク密度を増大させる事は容易ではなくさまざ
まな要因がある。トラツク巾減少による信号レベ
ルの低下、媒体欠陥の顕在化、トラツク間クロス
トークの増大、トラツク追従の困難さである。中
でも最大の問題は磁気ヘツドのトラツク追従の困
難さである。磁気ヘツドの目的トラツクからの位
置誤差が正確に得られるか否かがトラツク追従の
正確さを規定するものであるが、この点に現在の
システムは問題があるとされている。
特公昭41−2586号公報に記載される磁気二重層
媒体は二層の磁性体層を用い下層磁性体層に表面
から磁気ヘツドの位置誤差信号検出用のサーボ情
報を磁気的に記録し、磁気ヘツドは下層磁性体層
に記録されたサーボ情報から位置誤差信号が得ら
れるものであり、正確な位置誤差信号が得られる
ものである。しかしながら上下の磁性体層は何れ
も磁気的に記録され得るものであり、データを上
層磁性体層に記録する毎に下層磁性体層が何らか
の影響を受ける事は原理上避けられない。また磁
気記録媒体完成後に、サーボ情報を記録しなけれ
ばならないので、その為に多大の記録及び検査時
間を要するものであり必ずしも量産に適している
方法ではない等の欠点が存在する。
本発明はこのような状況に鑑みて為されたもの
であり、磁気二重層の概念を用いながら、サーボ
情報の恒久的な安定性、量産性を可能にし、さら
に高トラツク密度の装置では不可欠なトラツクア
ドレス、その他識別情報をも同時に形成せしめる
ような磁気記録媒体を提供する。以下に図面を用
いて本発明の原理、作用、効果を詳しく説明す
る。
第１図〜第３図は本発明による磁気記録媒体を
磁気デイスクの形で実現した場合の第１の実施例
を示している。第１図において本発明の第１の実
施例である磁気デイスク１０は、同心円状のトラ
ツク１１を有しそのトラツク１１は、同図におい
ては４つのセクターに分かれ、各々のセクター
は、トラツクアドレス、セクターアドレス等が記
録されている識別部１２とデータ部１３とから成
つているものとする。番号１４は磁気デイスク１
０の回転方向を示す。
第２図は、第１図における磁気デイスク１０の
トラツク１１に沿つた円周方向の拡大断面図であ
る。第２図において製造法の概略を説明すると、
まずよく研磨されたアルミニウム合金より成る基
板２１上に中間層２２としてニツケルを厚くメツ
キした後再度研磨して平滑な面に仕上げる。つぎ
に抗磁力の大きな薄膜の磁性体、例えばコバル
ト、プラチナの合金をメツキで付着せしめ、所定
のパターンに喰刻により仕上げて下層磁性体層２
３を形成する。さらにその上に下層磁性体層２３
の凹凸を除去するために緩衝層２４を付着せしめ
る。材質はフオトレジストのような高分子化合物
でもよいし、ニツケルを再度メツキして研磨して
もよい。この緩衝層２４の上にデータ記録用の上
層磁性体層２５を設ける。上層磁性体層として
は、ニツケル、コバルト、リン等の合金をメツキ
によつて形成してもよいし、あるいはｒ―Fe2O3
をバインダーと共にスピンコーテイングによつて
形成してもよい。後者の場合には緩衝層２４を場
合によつては省略できる。しかる後に磁気デイス
ク１０を円周方向（すなわちトラツク方向）に沿
つて十分に大きな直流磁界をかけ下層磁性体層２
３に磁化２６を生ぜしめる。下層磁性体層２３は
本実施例のように一部が残されているのみである
ので端面から磁束が漏洩する。漏洩磁束２７は上
層磁性体層２５及び磁気デイスク１０外に存在し
磁気ヘツドによる検出が可能となるものである。
ここで番号１２は、第１図におけると、同様に識
別部を示し、トラツクアドレス、セクターアドレ
ス等に対応するパターンに下層磁性体層２３が形
成されている。使用時においては、上層磁性体層
２５に何らかの信号が磁気ヘツドによつてなされ
磁化が残留すると、識別部１２の読取りの際の防
害となるので識別部１２に対応する上層磁性体層
２５は下層磁性体層２３よりの漏洩磁束２７で磁
気的に飽和させる事が必要である。それには緩衝
層２４の厚みも関与するが要は、識別部１２にお
ける下層磁性体層２３のパターンの端面からの漏
洩磁束２７が、上層磁性体層２５の飽和磁束密度
及び厚さで決まる飽和に必要な磁束量より大とな
るように材料を選択すればよいのである。データ
部１３にある下層磁性体層２３のパターンは、第
３図にそれらの平面図を示すように、パターンの
巾を狭くすることによりデータ部１３における下
層磁性体層２３からの漏洩磁束２７では、上層磁
性体層２５が飽和に至らないようにされている。
データ部１３における下層磁性体層２３のパター
ンがサーボ情報に関連するもので上層磁性体層２
５に記録されるデータより周波数的に分離しやす
いよう十分に低い記録密度となるように選ばれて
いるが、本実施例の場合第３図に示すようトラツ
クの中央に下層磁性体層２３のパターンが形成さ
れ、少くとも３種以上の周波数がサーボ信号に割
り当られている。すなわちその周波数をf1，f3と
すると隣接するトラツク毎に順次f1，f2，f3の周
波数に対応するパターンがデータ部１３内の下層
磁性体層２３に形成される。磁気デイスク装置は
左右のトラツクからのサーボ信号レベルをフイル
ターによつて区分して知り磁気ヘツドの位置誤差
信号を、得る事ができるものである。このように
本発明による磁気記録媒体を第１図、第２図、第
３図に示す実施例によつて説明したように本発明
による目的を十分に達成する事ができる。
すなわち、第２図を用いて製造の手順の概略を
説明した事から判明するように識別部１２、デー
タ部１３のサーボ情報は下層磁性体層２３に物理
的に形成されたパターンに依存しているので極め
て磁気的には破壊されにくく、しかも従来の磁気
２重層のように、磁気ヘツドによつてサーボ情報
を記録するのではなく単に、一方向に磁化するの
みであるので大きな磁界を使用する事も可能であ
るので下層磁性体層２３として十分に抗磁力の大
きい材料を選択できるものであり記録再生用磁気
ヘツドによるサーボ情報の破壊からは完全に回避
できる。さらに下層磁性体層２３のパターンは予
め作製し検査の終了したマスクによつて喰刻を行
つて形成するものであり、極めて量産に適してい
る。
第４図及び第５図は本発明による磁気記録媒体
の第２の実施例を示す。第４図は第１の実施例を
示す第２図に対応し磁気デイスク１０のトラツク
方向の断面を示し、第５図は下層磁性体層２３の
平面パターンを示す。それらの図から判明するよ
うに第２の実施例は下層磁性体層２３のパターン
のみが第１の実施例と異つているのであり、丁度
喰刻によつて除去されるパターンと残留するパタ
ーンが逆になつている。この第２の実施例のよう
に下層磁性体層２３のパターンを構成しても端面
からは磁束が漏れ出るので原理、作用は第１の実
施例と同様となる。残留する面積が多いので記録
再生用の磁気ヘツドの影響に対してはむしろ強く
なると云う利点がある。
第６図は、本発明による磁気記録媒体の第３の
実施例を説明する為の図であるが、第２の実施例
と異る点は第６図を第５図と比較すれば判明する
ように、サーボ情報に関係する下層磁性体層２３
のパターンをトラツクの中央からトラツク間のガ
ードバンドに移動させた事である。この場合に
は、トラツクの両側で下層磁性体層２３のパター
ン周期を変え、再生した時に周波数が異るように
配慮する必要がある。
以上、本発明について３つの実施例を挙げて説
明したが、全く同様な構成で印加する磁界の方向
を、膜面とは垂直に選ぶ事もできる。
すなわち、下層磁性体層２３として抗磁力が十
分に大で膜面と垂直な方向の磁化が保たれるよう
な材料を用いれば前記実施例でトラツク方向に印
加した直流磁界を膜面に垂直とする事ができる。
原理的に、上層磁性体層２５への記録が長手方向
記録である場合には影響が少く好ましい方法とい
える。
したがつて本発明による磁気記録媒体はデータ
の記録再生を行う磁性体層より下層の磁性体層か
ら、磁気ヘツドの位置決めに必要なサーボ情報、
トラツクアドレス、セクタアドレス等の識別情報
が得られるもので高トラツク密度記録に適し、し
かもそれらのサーボ情報、識別情報は製造時に予
じめ用意されたマスクによつて恒久的に形成され
るもので量産に適すると共に極めて安定である特
徴を有するもので本発明の目的を十分に満足す
る。
ただ上記の説明は実施例について示したもので
あり本発明の趣旨を変えない範囲で種々の変形、
変更、例えば製造手順の変更、材料の変更、記録
媒体を構成する層の付加、サーボ情報に関係する
パターンの変更等が可能な事は勿論であつて上記
の説明が本発明の範囲を限定するものではない。 DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic recording medium, and in particular, servo information regarding the difference in position error detection between a recording track and a magnetic head, a track address, and other identification information are permanently formed during manufacturing. The present invention relates to a magnetic recording medium characterized by: Generally, magnetic recording is performed by alternately reversing the magnetization on a recording medium using a magnetic head.The locus that a magnetic head forms on a recording medium is called a track, and its width is determined by the width of the magnetic head and the magnetic field leaking from the magnetic head. In addition to the distribution, the track pitch is also related to the positioning error of the magnetic head. Recording density, which is one of the performance indicators of magnetic recording, is expressed by the linear density, which is the magnetization reversal density in the track direction, and the track density. In a magnetic disk device, the ratio of the two is usually 10:
It is about 1. Currently, due to the development of media materials and systematic improvements, the linear density has increased to 400 to 1 mm.
Although a magnetization reversal density of over 2000 has been achieved, the track density is still only around 40 lines per mm. Therefore, a shortcut to achieving high-density recording in magnetic recording is to increase the track density, and preferably to get it as close to the magnetization reversal density as possible. However, increasing track density is not easy and there are various factors involved. These problems include a decrease in signal level due to a decrease in track width, manifestation of media defects, increase in crosstalk between tracks, and difficulty in tracking tracks. The biggest problem among these is the difficulty in following the track of the magnetic head. The accuracy of track following is determined by whether the position error of the magnetic head from the target track can be accurately obtained, and current systems are said to have a problem in this respect. The magnetic double layer medium described in Japanese Patent Publication No. 41-2586 uses two magnetic layers and magnetically records servo information for detecting a position error signal of a magnetic head from the surface of the lower magnetic layer. The head is a device from which a position error signal can be obtained from servo information recorded in the lower magnetic layer, and an accurate position error signal can be obtained. However, both the upper and lower magnetic layers can be magnetically recorded, and it is inevitable in principle that the lower magnetic layer will be affected in some way every time data is recorded in the upper magnetic layer. Furthermore, since servo information must be recorded after the magnetic recording medium is completed, this method requires a large amount of recording and inspection time, and has drawbacks such as that it is not necessarily a method suitable for mass production. The present invention was made in view of this situation, and uses the concept of a magnetic double layer to enable permanent stability and mass production of servo information, which is essential for high track density equipment. To provide a magnetic recording medium on which track addresses and other identification information can be formed at the same time. The principle, operation, and effects of the present invention will be explained in detail below using the drawings. 1 to 3 show a first embodiment in which a magnetic recording medium according to the present invention is realized in the form of a magnetic disk. In FIG. 1, a magnetic disk 10 which is a first embodiment of the present invention has a concentric track 11, and the track 11 is divided into four sectors in the figure, and each sector has a track address, It is assumed that it consists of an identification section 12 in which sector addresses and the like are recorded, and a data section 13. Number 14 is magnetic disk 1
Indicates the rotation direction of 0. FIG. 2 is an enlarged circumferential sectional view of the magnetic disk 10 in FIG. 1 along the track 11. To explain the outline of the manufacturing method in Figure 2,
First, a thick layer of nickel is plated as an intermediate layer 22 on a well-polished aluminum alloy substrate 21, and then polished again to give a smooth surface. Next, a thin film of magnetic material with high coercive force, such as an alloy of cobalt or platinum, is attached by plating and finished by etching into a predetermined pattern to form the lower magnetic layer 2.
form 3. Furthermore, a lower magnetic layer 23 is provided on top of that.
A buffer layer 24 is deposited to remove the unevenness. The material may be a polymer compound such as photoresist, or nickel may be plated again and polished. On this buffer layer 24, an upper magnetic layer 25 for data recording is provided. The upper magnetic layer may be formed by plating an alloy of nickel, cobalt, phosphorus, etc., or r-Fe 2 O 3
may be formed by spin coating with a binder. In the latter case, the buffer layer 24 may be omitted in some cases. Thereafter, a sufficiently large direct current magnetic field is applied to the magnetic disk 10 along the circumferential direction (that is, the track direction) to form the lower magnetic layer 2.
3 to produce magnetization 26. Since only a portion of the lower magnetic layer 23 remains as in this embodiment, magnetic flux leaks from the end face. The leakage magnetic flux 27 exists outside the upper magnetic layer 25 and the magnetic disk 10 and can be detected by the magnetic head.
Here, the number 12 designates an identification part similarly to that in FIG. 1, and a lower magnetic layer 23 is formed in a pattern corresponding to a track address, a sector address, etc. During use, if some signal is sent to the upper magnetic layer 25 by the magnetic head and magnetization remains, this will prevent damage when reading the identification section 12, so the upper magnetic layer 25 corresponding to the identification section 12 will be It is necessary to magnetically saturate it with the leakage magnetic flux 27 from the lower magnetic layer 23. Although the thickness of the buffer layer 24 also plays a role in this, the important point is that the leakage magnetic flux 27 from the end face of the pattern of the lower magnetic layer 23 in the identification section 12 reaches saturation determined by the saturation magnetic flux density and thickness of the upper magnetic layer 25. The material should be selected so that the amount of magnetic flux is larger than the required amount. As shown in the plan view of FIG. 3, the patterns of the lower magnetic layer 23 in the data section 13 are designed to reduce the leakage magnetic flux 27 from the lower magnetic layer 23 in the data section 13 by narrowing the pattern width. , the upper magnetic layer 25 is prevented from reaching saturation.
The pattern of the lower magnetic layer 23 in the data section 13 is related to servo information, and the pattern of the upper magnetic layer 23 is related to servo information.
However, in this embodiment, as shown in FIG. 3, the lower magnetic layer 23 is placed in the center of the track. A pattern is formed, and at least three or more frequencies are assigned to the servo signal. That is, assuming that the frequencies are f 1 and f 3 , patterns corresponding to the frequencies f 1 , f 2 , and f 3 are sequentially formed in the lower magnetic layer 23 in the data section 13 for each adjacent track. A magnetic disk device is capable of obtaining a position error signal of the magnetic head by separating the servo signal levels from the left and right tracks using a filter. As described above, the magnetic recording medium according to the present invention can fully achieve the objects of the present invention as explained by the embodiments shown in FIGS. 1, 2, and 3. That is, as is clear from the outline of the manufacturing procedure explained using FIG. It is extremely difficult to be destroyed magnetically, and unlike conventional magnetic double layers, it does not record servo information using a magnetic head, but simply magnetizes in one direction, so a large magnetic field is used. Therefore, a material having a sufficiently large coercive force can be selected for the lower magnetic layer 23, and destruction of servo information by the recording/reproducing magnetic head can be completely avoided. Furthermore, the pattern of the lower magnetic layer 23 is formed by etching using a mask that has been prepared and inspected in advance, making it extremely suitable for mass production. 4 and 5 show a second embodiment of the magnetic recording medium according to the present invention. FIG. 4 shows a cross section of the magnetic disk 10 in the track direction, corresponding to FIG. 2 showing the first embodiment, and FIG. 5 shows a planar pattern of the lower magnetic layer 23. As can be seen from these figures, the second embodiment differs from the first embodiment only in the pattern of the lower magnetic layer 23, and the pattern removed by etching and the remaining pattern are exactly the same. It's backwards. Even if the pattern of the lower magnetic layer 23 is configured as in the second embodiment, the magnetic flux leaks from the end face, so the principle and operation are the same as in the first embodiment. Since the remaining area is large, it has the advantage of being more resistant to the influence of magnetic heads for recording and reproducing. FIG. 6 is a diagram for explaining the third embodiment of the magnetic recording medium according to the present invention, and the differences from the second embodiment can be seen by comparing FIG. 6 with FIG. 5. As shown, the lower magnetic layer 23 related to servo information
The pattern was moved from the center of the track to the guard band between the tracks. In this case, it is necessary to change the pattern period of the lower magnetic layer 23 on both sides of the track so that the frequencies are different when reproduced. Although the present invention has been described above with reference to three embodiments, the direction of the applied magnetic field can also be chosen to be perpendicular to the film surface with a completely similar configuration. That is, if the lower magnetic layer 23 is made of a material that has a sufficiently large coercive force and maintains magnetization in the direction perpendicular to the film surface, the DC magnetic field applied in the track direction in the above embodiment can be made perpendicular to the film surface. I can do that.
In principle, if the recording on the upper magnetic layer 25 is performed in the longitudinal direction, this method has less influence and can be said to be a preferable method. Therefore, in the magnetic recording medium according to the present invention, servo information necessary for positioning the magnetic head,
It is suitable for high track density recording because it allows identification information such as track addresses and sector addresses to be obtained, and the servo information and identification information are permanently formed using masks prepared in advance during manufacturing. It is suitable for mass production and has the characteristics of being extremely stable and fully satisfies the purpose of the present invention. However, the above description is given regarding the embodiments, and various modifications and variations may be made without departing from the spirit of the present invention.
It is of course possible to make changes, such as changes in manufacturing procedures, changes in materials, addition of layers constituting the recording medium, changes in patterns related to servo information, etc., and the above description does not limit the scope of the invention. It's not a thing.
第１図、第２図、第３は本発明による磁気記録
媒体を磁気デイスク１０の形で実現した第１の実
施例を示すものであり、第１図は磁気デイスク１
０の平面図、第２図は円周方向に切断した場合の
磁気デイスク１０の断面図、第３図は下層磁性体
層２３のパターンの平面図をそれぞれ示す。第４
図、第５図は本発明による磁気記録媒体の第２の
実施例を示し、第４図は第２図と同様にトラツク
方向に切断した場合の断面図、第５図は下層磁性
体層２３のパターンの平面図をそれぞれ示す。さ
らに第６図は本発明による磁気記録媒体の第３の
実施例を示すもので下層磁性体層２３のパターン
の平面図を示す。
図において、１０は磁気デイスク、１１はトラ
ツク、１２は識別部、１３はデータ部、１４は磁
気デイスクの回転方向、２１は基板、２２は中間
層、２３は下層磁性体層、２４は緩衝層、２５は
上層磁性体層、２６は磁化方向、２７は漏洩磁束
をそれぞれ示す。
1, 2, and 3 show a first embodiment in which a magnetic recording medium according to the present invention is realized in the form of a magnetic disk 10 , and FIG.
2 is a cross-sectional view of the magnetic disk 10 when cut in the circumferential direction, and FIG. 3 is a plan view of the pattern of the lower magnetic layer 23. Fourth
5 shows a second embodiment of the magnetic recording medium according to the present invention, FIG. 4 is a sectional view taken in the track direction similarly to FIG. 2, and FIG. 5 is a sectional view of the lower magnetic layer 23. A plan view of each pattern is shown. Furthermore, FIG. 6 shows a third embodiment of the magnetic recording medium according to the present invention, and shows a plan view of the pattern of the lower magnetic layer 23. In the figure, 10 is a magnetic disk, 11 is a track, 12 is an identification section, 13 is a data section, 14 is a rotating direction of the magnetic disk, 21 is a substrate, 22 is an intermediate layer, 23 is a lower magnetic layer, and 24 is a buffer layer. , 25 indicates the upper magnetic layer, 26 indicates the magnetization direction, and 27 indicates the leakage magnetic flux.
Claims (1)
おいて、前記上層磁性体層より大きい抗磁力を有
する下層磁性体層は記録再生用の磁気ヘツドを介
して、前記磁気ヘツドのトラツクに対する位置誤
差信号及びトラツクアドレスその他の識別情報が
得られるように喰刻によりパターンが形成される
とともにトラツク方向あるいは膜面に垂直方向に
一様に磁化されて成り、上層磁性体層がデータ記
録用に用いられる事を特徴とする磁気記録媒体。 ２ 特許請求の範囲第１項記載の磁気記録媒体に
おいてトラツクに対する位置誤差検出に寄与させ
る下層磁性体層のパターンは磁束漏洩に寄与する
パターン面積を十分に小として上層磁性体層を磁
気的に飽和せしめる事なく、またトラツクアドレ
ス、識別情報発生に関与せしめる下層磁性体層の
パターンをトラツク巾内において十分にとる事に
より上層磁性体が磁気的に飽和するよう上下磁性
体層の磁気的性質及び厚さを選定した事を特徴と
する磁気記録媒体。[Scope of Claims] 1. In a magnetic recording medium consisting of two upper and lower magnetic layers, a lower magnetic layer having a coercive force greater than that of the upper magnetic layer is connected to the magnetic head via a recording/reproducing magnetic head. A pattern is formed by etching to obtain a position error signal for the track, a track address, and other identification information, and the upper magnetic layer is magnetized uniformly in the track direction or perpendicular to the film surface. A magnetic recording medium characterized by being used for recording. 2. In the magnetic recording medium according to claim 1, the pattern of the lower magnetic layer that contributes to position error detection with respect to the track is such that the pattern area contributing to magnetic flux leakage is sufficiently small to magnetically saturate the upper magnetic layer. The magnetic properties and thickness of the upper and lower magnetic layers are adjusted so that the upper magnetic layer is magnetically saturated by creating a pattern of the lower magnetic layer that is involved in track address and identification information generation sufficiently within the track width. A magnetic recording medium characterized by selected characteristics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57183217A JPS5972642A (en) | 1982-10-19 | 1982-10-19 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57183217A JPS5972642A (en) | 1982-10-19 | 1982-10-19 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5972642A JPS5972642A (en) | 1984-04-24 |
| JPS6325405B2 true JPS6325405B2 (en) | 1988-05-25 |
Family
ID=16131828
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57183217A Granted JPS5972642A (en) | 1982-10-19 | 1982-10-19 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5972642A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56148735A (en) * | 1980-04-21 | 1981-11-18 | Matsushita Electric Ind Co Ltd | Magnetic disc |
-
1982
- 1982-10-19 JP JP57183217A patent/JPS5972642A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS56148735A (en) * | 1980-04-21 | 1981-11-18 | Matsushita Electric Ind Co Ltd | Magnetic disc |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5972642A (en) | 1984-04-24 |
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