JPH01100752A - Magnetic recording and optical reproducing/recording medium - Google Patents
Magnetic recording and optical reproducing/recording mediumInfo
- Publication number
- JPH01100752A JPH01100752A JP62256386A JP25638687A JPH01100752A JP H01100752 A JPH01100752 A JP H01100752A JP 62256386 A JP62256386 A JP 62256386A JP 25638687 A JP25638687 A JP 25638687A JP H01100752 A JPH01100752 A JP H01100752A
- Authority
- JP
- Japan
- Prior art keywords
- film
- medium
- magnetic field
- vertical
- curie temperature
- 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
Links
- 230000005291 magnetic effect Effects 0.000 title claims abstract description 75
- 230000003287 optical effect Effects 0.000 title claims description 10
- 239000010408 film Substances 0.000 claims abstract description 32
- 239000010409 thin film Substances 0.000 claims abstract description 24
- 239000000696 magnetic material Substances 0.000 claims abstract description 9
- 230000005415 magnetization Effects 0.000 claims description 16
- 239000000758 substrate Substances 0.000 claims description 6
- 229910000889 permalloy Inorganic materials 0.000 claims description 5
- 229910000859 α-Fe Inorganic materials 0.000 claims description 3
- 229910001152 Bi alloy Inorganic materials 0.000 claims description 2
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 2
- 229910052771 Terbium Inorganic materials 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 claims description 2
- 229910045601 alloy Inorganic materials 0.000 claims 3
- 239000000956 alloy Substances 0.000 claims 3
- 229910052761 rare earth metal Inorganic materials 0.000 claims 2
- 229910052723 transition metal Inorganic materials 0.000 claims 2
- 150000003624 transition metals Chemical class 0.000 claims 2
- 229910052692 Dysprosium Inorganic materials 0.000 claims 1
- 229910052688 Gadolinium Inorganic materials 0.000 claims 1
- 229910052779 Neodymium Inorganic materials 0.000 claims 1
- 150000002910 rare earth metals Chemical class 0.000 claims 1
- 229910000702 sendust Inorganic materials 0.000 claims 1
- 238000010438 heat treatment Methods 0.000 abstract 1
- 238000000034 method Methods 0.000 description 10
- 230000008569 process Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005284 excitation Effects 0.000 description 2
- 230000007246 mechanism Effects 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 229910017061 Fe Co Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000006870 function Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
- G11B11/10534—Heads for recording by magnetising, demagnetising or transfer of magnetisation, by radiation, e.g. for thermomagnetic recording
- G11B11/10536—Heads for recording by magnetising, demagnetising or transfer of magnetisation, by radiation, e.g. for thermomagnetic recording using thermic beams, e.g. lasers
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
- G11B11/10504—Recording
- G11B11/10508—Recording by modulating only the magnetic field at the transducer
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10502—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing characterised by the transducing operation to be executed
- G11B11/10517—Overwriting or erasing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10582—Record carriers characterised by the selection of the material or by the structure or form
- G11B11/10586—Record carriers characterised by the selection of the material or by the structure or form characterised by the selection of the material
-
- 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
Landscapes
- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は高速で重ね書きの可能な光磁気デイク媒体に関
するものである。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magneto-optical disk medium that can be overwritten at high speed.
［従来の技術］
従来、光磁気ディスクへの記録（情報の書き込み）は、
−様に磁化した光記録媒体（Ｔｂ−Ｆｅ薄膜等の垂直磁
化薄膜）に対し、異方性磁界以下のバイアス磁場を磁化
と逆向きに加えつつ、レーザービームを照射して照射領
域の温度をキュリー温度以上に上げた後、媒体が冷却す
る過程でバイアス磁場の方向に磁化が反転することを利
用しており、レーザービームをオン・オフする事で磁化
反転の列として情報を記録していた（通常の光変調記＃
３）。この方式では一旦記録された領域に再度新しい情
報を記録する場合には、記録時とは逆向きのバイアス磁
場中で連続レーザービームを照射して媒体を加熱し、磁
化を全て一方向に揃える事（これを消去過程という）が
必要であった。即ち、消去して後に再度記録を行う必要
があり、通常の磁気記録における情報の書き込みのよう
に、予め記録されていた領域の上に別の情報を記録する
ことで、前の情報は自動的に消える事はなく、アクセス
速度の高速化上の障害となっていた。[Conventional technology] Conventionally, recording (writing information) on a magneto-optical disk was performed using the following steps.
A laser beam is irradiated onto an optical recording medium (perpendicularly magnetized thin film such as a Tb-Fe thin film) magnetized in a direction opposite to that of the magnetization while applying a bias magnetic field smaller than the anisotropic magnetic field in the opposite direction to the magnetization, and the temperature of the irradiated area is increased. After raising the temperature above the Curie temperature, the medium takes advantage of the fact that its magnetization reverses in the direction of the bias magnetic field as it cools, and by turning the laser beam on and off, information is recorded as a sequence of magnetization reversals. (Normal light modulation record #
3). In this method, when new information is to be recorded in an area that has already been recorded, a continuous laser beam is irradiated in a bias magnetic field in the opposite direction to that used during recording to heat the medium and align all magnetization in one direction. (This is called the elimination process) was necessary. In other words, it is necessary to erase and then record again, and just like writing information in normal magnetic recording, by recording new information on top of the previously recorded area, the previous information is automatically erased. This problem never disappeared and became an obstacle to increasing access speed.
上記問題を解決するため、最近、重ね書きの出来る光磁
気ディスクが提案されている。以下に、その動作メカニ
ズムを述べる。第３図に光磁気デ゛ イスクの概略を示
す。１は光磁気ディスク用基板、２は記録媒体、３はレ
ーザー光、４は光ヘッド、５は信号磁界印加用コイルで
ある。ディスクが回転している時、この媒体は光ヘッド
の下に移動して光ビームで加熱される。加熱された領域
は、キュリー温度以上となるため非磁性になり、書き込
まれていたビットは消去される。媒体が移動してレーザ
ービームで照射された領域の温度が低下する時に、信号
磁界を印加すれば、記録媒体の磁化は信号磁界の方向に
揃う（磁界変調記録）。書き込まれた情報は、通常の光
変調記録の場合と同様に、レーザービームの反射光の偏
光面の回転角の差として読み出すことができる。In order to solve the above problems, magneto-optical disks that allow overwriting have recently been proposed. The operating mechanism will be described below. Figure 3 shows an outline of the magneto-optical disk. 1 is a magneto-optical disk substrate, 2 is a recording medium, 3 is a laser beam, 4 is an optical head, and 5 is a coil for applying a signal magnetic field. As the disk rotates, this medium moves beneath the optical head and is heated by the light beam. The heated region reaches a temperature higher than the Curie temperature, becomes non-magnetic, and the written bit is erased. If a signal magnetic field is applied when the medium moves and the temperature of the region irradiated with the laser beam decreases, the magnetization of the recording medium is aligned in the direction of the signal magnetic field (magnetic field modulation recording). The written information can be read out as a difference in the rotation angle of the polarization plane of the reflected laser beam, as in the case of normal optical modulation recording.
しかしながら、記録媒体としてＴｂ −Ｆｅ −Ｃｏ薄
膜を用いた例では、信号磁界として数百０ｅ以上の高磁
場が必要である（電気学会マグネティックス研究会二田
中富士雄、田中ｆ８介、今村修武「磁界変調記録法によ
るオーバーライド」講演番号ＭＡＧ−８６−９５）。光
磁気ディスクは一般にカセットに収納されており記録媒
体と信号磁界印加用コイルとの間隔が数ｎｏｎ以上であ
ることを考慮すると、このような高い磁場を得るために
は信号電流がなかつ大きくなるため、装置の発熱等の問
題を内在するといえる。また、大電流を流すコイルは必
然的に大型にならざるをえず、コイルのインダクタンス
が増大する。このため、高周波の信号電流をコイルに流
すことが困難になり、データ転送に高速化に支障をきた
す。上記の例では、数ＭＨｚが駆動周波数の上限となっ
ている。However, in the case of using a Tb-Fe-Co thin film as a recording medium, a high magnetic field of several hundred e or more is required as a signal magnetic field (Fujio Nitanaka, F8 Tanaka, Osamu Imamura, Magnetics Research Group, Institute of Electrical Engineers of Japan). "Override by Magnetic Field Modulation Recording Method" Lecture No. MAG-86-95). Considering that magneto-optical disks are generally housed in cassettes and the distance between the recording medium and the signal magnetic field applying coil is several nanometers or more, the signal current must be very large to obtain such a high magnetic field. , it can be said that there are inherent problems such as heat generation of the device. Further, a coil through which a large current flows must necessarily be large in size, which increases the inductance of the coil. This makes it difficult to flow a high-frequency signal current through the coil, which hinders high-speed data transfer. In the above example, several MHz is the upper limit of the driving frequency.
次に重ね書き方式による記録動作メカニズムを述べる。Next, the recording operation mechanism using the overwriting method will be described.
第４図は光磁気ディスクの例である。１は光磁気ディス
ク用基板、２はレーザー光、３は光ヘッド、６は第１の
媒体、７は第２の媒体、８は磁気記録用ヘッドである。FIG. 4 is an example of a magneto-optical disk. 1 is a magneto-optical disk substrate, 2 is a laser beam, 3 is an optical head, 6 is a first medium, 7 is a second medium, and 8 is a magnetic recording head.
第４図において、ディスクが矢印方向へと回転している
時、先ず第１の媒体６に対して磁気ヘッド８から発生す
る磁場で情報を記録する。この過程は従来の磁気記録に
おける書き込みプロセスと同一であり、薄膜ヘッド等の
従来型磁気ヘッドを用いれば数十ＭＨｚの周波数まで駆
動できる。この時の記録磁界は第１の媒体６の保磁力よ
り高く、かつ、第２の媒体７の保磁力よりは低い値に設
定する。従って第１の媒体６のみが情報を書き込まれ第
２の媒体７には情報は記録されない。第２の媒体７への
情報の記録は次ぎの過程を経て完結する。媒体が記録ヘ
ッド４の下に移動して光ビーム３で加熱される。この時
に、光ビームのパワーは照射部分の最高温度が第２の媒
体７のキュリー温度以上、第１の媒体６のキュリー温度
以下となるように設定する。第２の媒体７が非磁性にな
るのに対し、第１の媒体６はキュリー温度が高いため、
磁化情報は破壊されずに残っておりそのビットからは溜
れ磁界が発生している。次ぎに、媒体が移動してレーザ
ービ−ムで照射された領域の温度が低下してきた場合に
は、第２の媒体７の磁化は第１の媒体６から発生する磁
場方向に揃うため、第１の媒体６に書き込まれた磁化情
報は第２の媒体７に転写される。即ち、光ビーム３の幅
のトラックで第２の媒体７上には磁気情報が記録される
。In FIG. 4, when the disk is rotating in the direction of the arrow, information is first recorded on the first medium 6 using the magnetic field generated by the magnetic head 8. This process is the same as the writing process in conventional magnetic recording, and can be driven at frequencies of several tens of MHz using a conventional magnetic head such as a thin film head. The recording magnetic field at this time is set to a value higher than the coercive force of the first medium 6 and lower than the coercive force of the second medium 7. Therefore, only the first medium 6 is written with information, and the second medium 7 is not recorded with information. Recording of information on the second medium 7 is completed through the following process. The medium moves under the recording head 4 and is heated by the light beam 3. At this time, the power of the light beam is set so that the maximum temperature of the irradiated portion is higher than the Curie temperature of the second medium 7 and lower than the Curie temperature of the first medium 6. While the second medium 7 is non-magnetic, the first medium 6 has a high Curie temperature.
The magnetization information remains without being destroyed, and a residual magnetic field is generated from the bit. Next, when the medium moves and the temperature of the area irradiated with the laser beam decreases, the magnetization of the second medium 7 is aligned in the direction of the magnetic field generated from the first medium 6, so that The magnetization information written on the second medium 6 is transferred to the second medium 7. That is, magnetic information is recorded on the second medium 7 in tracks with the width of the light beam 3.
書き込まれた情報の再生はレーザービームの反射光の偏
光面の傾きの差として読み出すとかできる。この時のレ
ーザーパワーは、媒体温度が第２の媒体７のキュリー温
度よりも充分低い温度になるように設定する必要がある
。このディスクへの重ね書きは、第１の媒体６上へ磁気
ヘッドで新しい情報を書き加えれば達成できる。第１の
媒体６への重ね書きは通常−４０ｄＢ程度の消し残り成
分を伴うが、この値は極めて小さいと言える。この時、
両媒体のＨｃは第２の媒体７〉〉第１の媒体６なので重
ね書きのための磁場は第１の媒体６のみを磁化し第２の
媒体７には影響を及ぼさない。The written information can be reproduced by reading out the difference in the slope of the polarization plane of the reflected laser beam. The laser power at this time needs to be set so that the medium temperature is sufficiently lower than the Curie temperature of the second medium 7. This overwriting on the disk can be accomplished by writing new information onto the first medium 6 using a magnetic head. Overwriting on the first medium 6 usually involves an unerased component of about -40 dB, but this value can be said to be extremely small. At this time,
Since the Hc of both media is second medium 7>>first medium 6, the magnetic field for overwriting magnetizes only the first medium 6 and does not affect the second medium 7.
［発明が解決しようとする問題点１
本方式の特徴は、光磁気ディスクにおいて磁気記録と同
等のアクセス速度を持ち、しかも消去過程を経ずに新し
い情報を加えられる事である。しかしながら、この方法
には以下のような欠点がある。すなわちＣｏ −Ｃｒ／
Ｔｂ −Ｆｅ薄膜では薄膜の保磁力が大きいため、磁
化率が低く書き込み磁場は単調に発散する。従って、媒
体に加わる磁場の絶対値が低いだけでなくその分布もブ
ロードになる。[Problem to be Solved by the Invention 1] The feature of this system is that a magneto-optical disk has an access speed equivalent to that of magnetic recording, and new information can be added without going through an erasing process. However, this method has the following drawbacks. That is, Co-Cr/
Since the Tb-Fe thin film has a large coercive force, the magnetic susceptibility is low and the write magnetic field monotonically diverges. Therefore, not only the absolute value of the magnetic field applied to the medium is low, but also its distribution is broad.
媒体の磁化反転は磁場の絶対値が大きいと同時にその分
布も急峻であることが必要であり、コイル電流を増す等
してヘッド磁場を強めるだけでは磁場を強めてもその分
布をシャープにはできなかった。For magnetization reversal of the medium, it is necessary that the absolute value of the magnetic field is large and that its distribution is steep, so simply increasing the head magnetic field by increasing the coil current cannot sharpen the distribution even if the magnetic field is strengthened. There wasn't.
本発明は上述した従来の欠点を解決し、媒体に加わる磁
場の分布を急峻にし、小さな書き込み電流で大きな再生
出力を得ることのできる記録媒体を提供することを目的
とする。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional drawbacks, to provide a recording medium that can sharpen the distribution of the magnetic field applied to the medium and obtain a large reproduction output with a small write current.
［問題点を解決するための手段］
このような目的を達成するために、本発明は軟磁性体と
、軟磁性体上に形成された第１の垂直磁化膜と、第１の
垂直磁化膜上に形成された異方性磁場が第１の垂直磁化
膜の異方性磁場より太き（かつキュリー温度が第１の垂
直磁化膜のキュリー温度より低い第２の垂直磁化膜とを
有することを特徴とする。[Means for Solving the Problems] In order to achieve such an object, the present invention includes a soft magnetic material, a first perpendicular magnetization film formed on the soft magnetic material, and a first perpendicular magnetization film. and a second perpendicularly magnetized film whose Curie temperature is lower than the Curie temperature of the first perpendicularly magnetized film. It is characterized by
［作 用］
磁気ヘッドで媒体１に対し情報を記録する場合には磁気
記録媒体１の磁化反転が完全に行われることが望ましい
。このためには、磁気ヘッドから発生する記録磁場の垂
直成分が大きくかつその分布が急峻であることが重要で
ある。このような目的を達成するために第１の媒体６の
裏側にパーマロイ等の軟磁性体薄膜を設ける事は極めて
有効である。すなわち第１の媒体を挟んで磁気ヘッドと
軟磁性体薄膜が存在するため、軟磁性体薄膜は磁束の通
り道を形成する事となる。もし、軟磁性体薄膜の透磁率
が無限大であれば、鏡像効果によって第１の媒体に加わ
る垂直磁場は２倍に強められると同時に、垂直磁場の分
布も急峻になる。[Function] When recording information on the medium 1 with a magnetic head, it is desirable that the magnetization of the magnetic recording medium 1 be completely reversed. For this purpose, it is important that the perpendicular component of the recording magnetic field generated from the magnetic head is large and its distribution is steep. To achieve this purpose, it is extremely effective to provide a soft magnetic thin film such as permalloy on the back side of the first medium 6. That is, since the magnetic head and the soft magnetic thin film exist with the first medium in between, the soft magnetic thin film forms a path for the magnetic flux. If the magnetic permeability of the soft magnetic thin film is infinite, the perpendicular magnetic field applied to the first medium will be doubled due to the mirror image effect, and the distribution of the perpendicular magnetic field will also become steeper.
［実施例］
第１図に、本発明による光磁気ディスクの実施例の概略
を示す。光磁気ディスク用基板上に７８ａｔ％Ｎｉ −
２２ａｔ％Ｆｅからなる初透磁率約４，０００ 。[Embodiment] FIG. 1 schematically shows an embodiment of a magneto-optical disk according to the present invention. 78 at% Ni − on the magneto-optical disk substrate
Initial magnetic permeability approximately 4,000, consisting of 22at%Fe.
キュリー温度的５８０℃のパーマロイ薄＠９を０．５μ
ｍ形成後、第１の媒体として７８．５％Ｃｏ −２１，
５％Ｃｒ薄膜６（異方性磁場４５０００ｅ、キュリー温
度的６００℃）を１０００人厚形成し、引き続きその上
に第２の媒体として７９％Ｆｅ−２１％Ｔｂ薄膜７（異
方゛性磁場１５０００ｅ、キュリー温度約１２５℃）を
ａＯＯ人厚形厚形成。比較のためにパーマロイ薄膜９を
省略した構造の媒体も形成した。基板としてガラス円板
上に２２剤を塗布後ホトリソグラフ技術を用いて同心円
状のトラック溝を形成したものである。本実施例では磁
気記録用ヘッドは、垂直磁化記録を目的としているので
主磁極励磁型の構造となっているが、原理的にはリング
型でもあるいは補助磁極励磁型でも垂直磁化記録は可能
である。Permalloy thin @9 with a Curie temperature of 580℃, 0.5μ
After m formation, 78.5% Co-21 as the first medium,
A 5% Cr thin film 6 (anisotropic magnetic field 45,000e, Curie temperature 600°C) was formed to a thickness of 1,000 layers, and then a 79% Fe-21% Tb thin film 7 (anisotropic magnetic field 15,000e) was formed as a second medium thereon. , Curie temperature of about 125°C). For comparison, a medium with a structure in which the permalloy thin film 9 was omitted was also formed. Agent 22 was coated on a glass disk as a substrate, and then concentric track grooves were formed using photolithography. In this example, the magnetic recording head is intended for perpendicular magnetization recording, so it has a main pole excitation type structure, but in principle, perpendicular magnetization recording is also possible with a ring type or auxiliary pole excitation type. .
ディスクが矢印方向へと回転している時、先ず、Ｃｏ−
［：ｒ媒体に対して主磁極から発生する磁場で情報を記
録する。この過程は従来のｌｉｌ気記録における書き込
みプロセスと同一である。この時の記録電流値と記録用
磁気ヘッドで再生した出力の関係を第２図に示す。記録
電流値はヘッド磁極先端が磁気的に飽和しない範囲内で
は書き込み磁場の強度に比例すると考λられる。即ち、
パーマロイ薄膜を形成した場合の方が同一再生出力を得
るための書き込み電流値が数十分の−の低下する事が判
る。When the disk is rotating in the direction of the arrow, first, Co-
[:r Information is recorded on the medium using a magnetic field generated from the main magnetic pole. This process is the same as the writing process in conventional memory recording. The relationship between the recording current value at this time and the output reproduced by the recording magnetic head is shown in FIG. It is considered that the recording current value is proportional to the strength of the write magnetic field within a range in which the tip of the head magnetic pole is not magnetically saturated. That is,
It can be seen that when a permalloy thin film is formed, the write current value for obtaining the same reproduction output is reduced by several tens of minutes.
なお、本実施例における第１および第２の媒体は各々高
キュリー温度、及び低キユリー温度高異方性磁場の垂直
膜の例であり、この他にも第１の媒体としては垂直磁気
記録用媒体として検討されているバリウムフェライト膜
、Ｃｏ−Ｃｒ合金の種々の添加元素を加えた膜等が、第
２の媒体としては光磁気記録用媒体であるＭｎ−Ｂｉ合
金膜、 ＹＩＧ ＠。The first and second media in this example are examples of perpendicular films with a high Curie temperature and a low Curie temperature and high anisotropy magnetic field, respectively. Barium ferrite films and Co-Cr alloy films with various additive elements are being considered as media, while Mn-Bi alloy films, which are magneto-optical recording media, and YIG@ are used as second media.
ＣＯフェライト膜等が適用出来る。CO ferrite film etc. can be applied.
［発明の効果］
以上述べたように、軟磁性体薄膜、高キュリー温度の垂
直異方性磁化薄膜、低キユリー温度の垂直異方性磁化薄
膜の３層構造薄膜とすることで、磁気的に情報を記録す
る場合の磁場が著しく低減でき、磁気ヘッド媒体間隔を
広く設定することや、高周波駆動時の発熱量を少なく抑
えることができる。[Effects of the invention] As described above, by creating a thin film with a three-layer structure of a soft magnetic thin film, a perpendicularly anisotropic magnetized thin film with a high Curie temperature, and a perpendicularly anisotropic magnetized thin film with a low Curie temperature, magnetically The magnetic field used when recording information can be significantly reduced, the magnetic head medium interval can be set wide, and the amount of heat generated during high-frequency driving can be suppressed.
第１図本発明による磁気記録、光再生方式の記録媒体の
実施例を示す図、
第２図は軟磁性膜がある場合および、無い場合の再生出
力の書き込み電流依存性を示す図、第３図および第４図
は従来の光磁気ディスクの概要図である。
１・・・光磁気ディスク用基板、
２・・・記録媒体、
３・・・レーザー光、
４・・・光ヘッド、
５・・・信号磁界印加用コイル、
６・・・第１の媒体、
７・・・第２の媒体、
８・・・磁気記録用ヘッド、
９・・・軟磁性膜。Fig. 1 is a diagram showing an embodiment of a magnetic recording/optical reproducing recording medium according to the present invention; Fig. 2 is a diagram showing write current dependence of reproduction output with and without a soft magnetic film; Fig. 3 2 and 4 are schematic diagrams of conventional magneto-optical disks. DESCRIPTION OF SYMBOLS 1... Magneto-optical disk substrate, 2... Recording medium, 3... Laser light, 4... Optical head, 5... Signal magnetic field application coil, 6... First medium, 7... Second medium, 8... Magnetic recording head, 9... Soft magnetic film.
Claims (1)
磁化膜と、該第１の垂直磁化膜上に形成された異方性磁
場が第１の垂直磁化膜の異方性磁場より大きくかつキュ
リー温度が第１の垂直磁化膜のキュリー温度より低い第
２の垂直磁化膜とを有することを特徴とする磁気記録、
光再生用記録媒体。 ２）前記軟磁性体がパーマロイ、センダスト、Ｃｏ−Ｚ
ｒ合金またはフェライトのいずれかからなる薄膜または
基板であり、前記第１の垂直磁化膜がＣｏ−Ｃｒ合金膜
、Ｃｏ−Ｃｒを主成分とする合金膜またはバリウムフェ
ライト膜のいずれかであり、かつ前記第２の垂直磁化膜
が希土類・遷移金属合金薄膜（希土類元素はＴｂ、Ｇｄ
、Ｎｄ、Ｄｙののうち少なくとも１種類以上、遷移金属
としてはＦｅ、Ｃｏ、Ｎｉのうち少なくとも１種類以上
を含む）、Ｍｎ−Ｂｉ合金膜、ＹＩＧ膜、Ｃｏフェライ
ト薄膜のいずれかであることを特徴とする特許請求の範
囲第１項記載の磁気記録、光再生用記録媒体。[Claims] 1) A soft magnetic material, a first perpendicularly magnetized film formed on the soft magnetic material, and an anisotropic magnetic field formed on the first perpendicularly magnetized film. a second perpendicularly magnetized film whose Curie temperature is larger than the anisotropic magnetic field of the perpendicularly magnetized film and whose Curie temperature is lower than the Curie temperature of the first perpendicularly magnetized film;
Recording medium for optical reproduction. 2) The soft magnetic material is permalloy, sendust, Co-Z
a thin film or substrate made of either an r-alloy or ferrite, and the first perpendicularly magnetized film is a Co-Cr alloy film, an alloy film containing Co-Cr as a main component, or a barium ferrite film, and The second perpendicular magnetization film is a rare earth/transition metal alloy thin film (the rare earth elements are Tb, Gd
, Nd, and Dy; transition metals include at least one of Fe, Co, and Ni), Mn-Bi alloy film, YIG film, and Co ferrite thin film. A recording medium for magnetic recording and optical reproduction according to claim 1.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62256386A JPH01100752A (en) | 1987-10-13 | 1987-10-13 | Magnetic recording and optical reproducing/recording medium |
| US07/188,876 US5051970A (en) | 1987-05-08 | 1988-05-02 | Magneto-optic recording system with overwrite capability |
| DE8888304128T DE3876133T2 (en) | 1987-05-08 | 1988-05-06 | DEVICE AND RECORD CARRIER FOR MAGNETO-OPTICAL RECORDING. |
| KR1019880005262A KR910003935B1 (en) | 1987-05-08 | 1988-05-06 | Magneto-opticla recording system |
| EP88304128A EP0291248B1 (en) | 1987-05-08 | 1988-05-06 | A magneto-optic medium and system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62256386A JPH01100752A (en) | 1987-10-13 | 1987-10-13 | Magnetic recording and optical reproducing/recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01100752A true JPH01100752A (en) | 1989-04-19 |
Family
ID=17291956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62256386A Pending JPH01100752A (en) | 1987-05-08 | 1987-10-13 | Magnetic recording and optical reproducing/recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01100752A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0598524A1 (en) * | 1992-11-19 | 1994-05-25 | Canon Kabushiki Kaisha | Magnetooptical recording medium |
-
1987
- 1987-10-13 JP JP62256386A patent/JPH01100752A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0598524A1 (en) * | 1992-11-19 | 1994-05-25 | Canon Kabushiki Kaisha | Magnetooptical recording medium |
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