JPH087350A - Magneto-optical recording medium and magneto-optical recording and reproducing apparatus - Google Patents

Magneto-optical recording medium and magneto-optical recording and reproducing apparatus

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Publication number
JPH087350A
JPH087350A JP14286794A JP14286794A JPH087350A JP H087350 A JPH087350 A JP H087350A JP 14286794 A JP14286794 A JP 14286794A JP 14286794 A JP14286794 A JP 14286794A JP H087350 A JPH087350 A JP H087350A
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magnetic
magneto
reproducing
magnetic field
magnetic domain
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JP14286794A
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JP3380621B2 (en )
Inventor
Hiroyuki Awano
博之 粟野
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Hitachi Ltd
Hitachi Maxell Ltd
日立マクセル株式会社
株式会社日立製作所
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Abstract

PURPOSE:To essentially improve amount of reproduced signal of a fine magnetic domain by transferring a magnetic domain of a recording layer to a reproducing layer where a coercive force is lowered because the layer is heated within an optical spot and then enlarging such magnetic domain with the reproduced magnetic field. CONSTITUTION:A recording magnetic domain 16 exists within a reproduced spot, a transferred and enlarged magnetic domain 17 appears when the enlarged magnetic field 7 is generated by a recording and reproduced magnetic field generator and thereby a signal is increased. Next, the magnetic field 7 is changed to the deleting direction to reproduce the adjacent magnetic domain 18. Thereby, the magnetic domain 17 disappears and the reproduced signal becomes zero. When the magnetic field is inverted to reproduce again the recording magnetic domain 18, the transferred enlarged magnetic domain 19 appears. When the magnetic field 7 is inverted again, the transferred and enlarged magnetic domain disappears. The compensating temperature of the intermediate layer is adequately set lower than the temperature at the center thereof to prevent that the enlarged magnetic domain is too widened to be deleted. Moreover, intensity of reproduced magnetic field must be set higher than the anti-magnetic force of magnetic wall but is lower than the coercive force of the reproducing layer at the temperature near the center temperature.

Description

【発明の詳細な説明】 DETAILED DESCRIPTION OF THE INVENTION

【0001】 [0001]

【産業上の利用分野】本発明は、光および/または磁界を変調して記録再生する光磁気記録媒体およびそれを用いた光磁気記録再生装置に関する。 The present invention relates to an optical magnetic recording and reproducing apparatus using the magneto-optical recording medium and its recording and reproducing by modulating light and / or magnetic fields.

【0002】 [0002]

【従来の技術】光磁気記録は、情報の記録・再生・消去が可能な光記録である。 [Magneto-optical recording is a recording, reproducing, and erasing capable optical recording of information. 現在利用されている光磁気ディスクの記録再生は光のスポット径に制限されている。 Recording and reproducing magneto-optical disks that are currently available are limited to the spot diameter of the light. このスポット径の半分以下の微小磁区を再生するにはパーシャルレスポンスや磁気的超解像、あるいは光学的超解像、2次元情報のクロストークキャンセルなど様々な方法が考えられている。 Partial response and magnetic super-resolution to play less than half a minute magnetic domain of the spot diameter, or optical superresolution, various methods such as crosstalk cancellation of the two-dimensional information has been considered. しかし、どの方法も微小磁区を光スポットの分解能を上げて再生する方法であり、本質的に信号量を改善する方法にはなっていない。 However, which method is a method of reproducing even minute magnetic domains to increase the resolution of an optical spot, not in a way to essentially improve the signal amount.

【0003】 [0003]

【発明が解決しようとする課題】本発明の課題は上記微小磁区の再生信号量を本質的に改善することにある。 The object of the present invention is to provide a is to essentially improve the reproduction signal amount of the minute magnetic domains.

【0004】 [0004]

【課題を解決するための手段】上記課題は、記録膜に交換結合3層磁性膜を用いたディスクにおいて、光スポット内で加熱され保磁力の低下した再生層に記録層の磁区を転写し、これを再生磁界により拡大することで解決される。 The object, according to an aspect of, in the disk using the exchange coupled tri-layered magnetic film on the recording film, to transfer the magnetic domain of the recording layer to decrease reproduction layer heated by the light spot the coercivity, This is solved by expanding the reproducing magnetic field. 例えば、図1に示したように(1)再生スポット内に記録磁区16があり、拡大磁界7を記録再生磁界発生装置により発生させ転写拡大磁区17が現われ、信号が増大する。 For example, there is a recording magnetic domain 16 (1) within the playback spot as shown in FIG. 1, to generate a larger magnetic field 7 by reproducing the magnetic field generator appear magnified transfer magnetic domain 17, the signal is increased. 次に隣接磁区18を再生するため磁界7を消去方向に切り替える。 Then switching the magnetic field 7 for reproducing the adjacent magnetic domains 18 in the erasing direction. (2)のように転写拡大磁区1 Transferring enlarged magnetic domain as shown in (2) 1
7は消滅し、再生信号は0となる。 7 disappears and the playback signal is zero. 再び記録磁区18を再生するために磁界7を(3)のように反転させると、 Reversing as a magnetic field 7 (3) for reproducing the recorded magnetic domain 18 again,
転写拡大磁区19が現われる。 Magnified transfer magnetic domain 19 appears. (4)のように再び磁界が反転すると転写拡大磁区は消滅する。 (4) again transcribed enlarged magnetic domain and the magnetic field is reversed as is extinguished. 記録膜の磁化の状態が変化する様子を図2から8まで示した。 How the magnetization state of the recording film changes shown from FIG. 2 to 8. 磁化状態は白矢印が全体の磁気モーメント、黒矢印は遷移金属の磁気モーメントを示す。 Magnetization state the entire magnetic moment is a white arrow, the black arrows indicate the magnetic moment of the transition metal. 着磁後は図2のような磁化状態となる。 After magnetization becomes magnetized state shown in FIG. これを初期化磁石を通過すると図3のような磁化状態になり、記録磁区は基板側から見えない。 When this is passed through an initialization magnet becomes magnetized state shown in FIG. 3, the recording magnetic domain can not be seen from the substrate side. レーザー光を照射し、転写磁界7を与えると記録磁区が転写される。 Irradiating a laser beam, the recording magnetic domain is transferred to confer transfer magnetic field 7. (図5)さらに磁界7を図6のように大きくすると磁性層2、3の磁区だけが保磁力が小さいため拡大し、大きな再生信号が得られる。 (Figure 5) further magnetic field 7 only greatly when the magnetic domain of the magnetic layers 2 and 3 as shown in FIG. 6 is an enlarged because small coercive force, a large reproduction signal is obtained. 次の磁区を読むためにはこれを消す必要がある。 To read the next magnetic domain, it is necessary to turn this off. 以上の内容は再生光をパルス状にすることでよりS/Nを高めることができる。 Above contents can enhance the S / N by pulsed reproduction light. これは図7のように先ほどと逆方向に磁界7を与えることで転写磁区は縮小し、さらに磁界を大きくすると図8のように消去が完成する。 This is copied magnetic domains by applying a magnetic field 7 in just the opposite direction as shown in FIG. 7 is reduced further by increasing the magnetic field erased as shown in FIG. 8 is completed. 図9には装置の構成図を示した。 It shows a block diagram of the apparatus in FIG.
第3磁性膜としては微小磁区記録の安定性の優れた希土類遷移金属合金が好ましい。 Excellent rare earth-transition metal alloy of the stability of the minute magnetic domains recorded is preferred as the third magnetic layer. 特に室温において希土類金属の磁気モーメントが優先的な組成が好ましい。 In particular the magnetic moment of the rare-earth metal is preferable preferential composition at room temperature.

【0005】拡大した磁区が広がり過ぎて消去できなくならないようにするためには、中間層の補償温度を再生光スポット中心温度よりも適度に低く設定しておけば良い。 [0005] In order to be expanded magnetic domains too spread not impossible erased, may be set appropriately lower than the compensation temperature of the intermediate layer reproducing light spot center temperature. また、再生磁界強度は再生時の光スポット中心温度付近での再生層の磁壁抗磁力以上保磁力以下にしておく必要がある。 Further, the reproducing magnetic field intensity is required to keep the following domain wall coercive force above the coercivity of the reproducing layer in the vicinity of the center of the light spot temperature during regeneration. また、このような微小磁区の拡大による信号量改善作以外にこの信号量変化を微分信号にして検出する方法もある。 In addition to the signal amount improve operation by the expansion of such minute magnetic domains is also a method of detecting by the signal amount changes to a differential signal. また、微小磁区を記録するためには第2磁性層のキュリー温度を微小磁区記録温度よりも低く設定しておく必要がある。 It is also necessary in order to record the minute magnetic domains can keep the Curie temperature of the second magnetic layer is set lower than the minute magnetic domains recorded temperature.

【0006】 [0006]

【作用】上記手段により、信号対雑音比S/Nは大幅改善する。 By the action above means, the signal-to-noise ratio S / N is significantly improved. また、隣接磁区の再生クロストークも大幅改善するためトラック密度、マークピッチ共に詰めることができるため高密度記録が可能になる。 Further, it is possible to high-density recording because it can be packed track density for also greatly improved reproduction crosstalk of the adjacent magnetic domains, the mark pitch both.

【0007】 [0007]

【実施例】 【Example】

(実施例1)試料は、スパッタ法により作成した。 (Example 1) Samples were prepared by sputtering. 作成条件は以下の通りである。 Creating conditions are as follows. 到達真空度5X10 -7 Tor Ultimate vacuum of 5X10 -7 Tor
r以下,スパッタガスにはArを用いガス圧は5mTo r or less, gas pressure with Ar as the sputtering gas 5mTo
rr,投入電力は500W,スパッタリングレートは0.1〜0.2nm/secである。 rr, input power is 500W, the sputtering rate is 0.1~0.2nm / sec. 誘電体膜には窒化物を用い、第1磁性層にはキュリー温度350度、補償温度が室温以下のGdTbFeCo合金を40nm、第2磁性層にはキュリー温度120度,補償温度60度のGdDyFe合金を20nm積層した。 The dielectric film using a nitride, Curie temperature 350 degrees in the first magnetic layer, the compensation temperature is 40nm below GdTbFeCo alloy room temperature Curie temperature 120 degrees in the second magnetic layer, the compensation temperature 60 ° GdDyFe alloy was 20nm stacked. 第3磁性層としては補償温度170度、キュリー温度240度のTbF The third compensation temperature 170 ° as a magnetic layer, the Curie temperature of 240 ° TbF
eCoを40nm積層した。 The eCo was 40nm stacked. 基板にはトラックピッチ1.6μmのサンプルサーボ基板を用いた。 Using sample servo substrate track pitch 1.6μm on the substrate.

【0008】記録に用いた変調磁界は200Oeで、ディスクの線速度は2.1m/secとした。 [0008] modulated magnetic field used for recording at 200 Oe, the linear velocity of the disk was 2.1 m / sec. 変調周波数2.5MHzで記録した磁区をサンプルクロックでタイミングをとって光パルスと磁界を5MHzで変調することにより再生を行なった。 And the magnetic domain recorded at the modulation frequency 2.5MHz timed sample clock was performed reproduced by modulating light pulses and magnetic field 5 MHz. 再生磁界は約100Oeで記録磁区だけが転写拡大され、再生磁界を約150Oeにすると再生層全体が反転した。 Reproducing magnetic field by the recording magnetic domain at about 100Oe is transferred enlarged, the entire reproduction layer to about 150Oe the reproducing magnetic field is inverted. また、再生磁界を約−1 In addition, the reproducing magnetic field about -1
00Oe印加すると再生磁区が消去された。 A reproduction magnetic domain to 00Oe applied has been erased. 再生は波長は680nmで行い、再生光と磁界を変調することでこれを行なわない場合に比べてS/Nに3dBの改善が見られた。 Reproduction wavelength was carried out at 680 nm, the improvement of 3dB in S / N as compared with the case without this by modulating the reproduction light and the magnetic field was observed. また、この信号変化を微分回路を通して再生したところさらにS/Nが1dB改善した。 Moreover, further S / N was reproducing the signal change through differentiating circuit is 1dB improvement.

【0009】 [0009]

【発明の効果】本発明によれば、光と磁界を変調して記録信号を再生すると微小磁区を拡大して信号量を本質的に増加させることが出きるため、大幅な信号対雑音比の改善が可能になり、また、再生後瞬時に拡大した磁区を消去できるので再生のクロストークも大幅に改善できる。 According to the present invention, since it essentially increase the light and magnetic field to expand the minute magnetic domains when reproducing the recorded signal by modulating the signal amount as possible out, significant signal-to-noise ratio improvement is possible, also, play cross-talk it is possible to erase the magnetic domain was expanded instantaneously after the reproduction can be significantly improved.

【図面の簡単な説明】 BRIEF DESCRIPTION OF THE DRAWINGS

【図1】図1は本発明の磁界変調再生の原理図。 FIG. 1 is a principle diagram of a magnetic field modulation regeneration of the present invention.

【図2】図2は着磁後の磁化の状態図。 FIG. 2 is a state diagram of the magnetization after magnetization.

【図3】図3は記録後の磁化の状態図。 FIG. 3 is a state diagram of the magnetization after recording.

【図4】図4は初期化磁石を通過したあとの磁化の状態図。 FIG. 4 is a state diagram of the magnetization after having passed through the initialization magnet.

【図5】図5は再生時記録磁区を転写したときの磁化の状態図。 FIG. 5 is a state diagram of the magnetization at the time of the transfer of the playback time of the recording magnetic domain.

【図6】図6は再生時転写した磁区を拡大したときの磁化の状態図。 FIG. 6 is a state diagram of the magnetization when the enlarged magnetic domain has been transferred during playback.

【図7】図7は再生時に転写した磁区を消去するときの磁化の状態図。 FIG. 7 is a state diagram of the magnetization of the time to erase the magnetic domain has been transferred at the time of reproduction.

【図8】図8は再生時に転写磁区を完全に消去したときの磁化の状態図。 FIG. 8 is a state diagram of the magnetization of the time you clear the complete transfer magnetic domain at the time of reproduction.

【図9】図9は光磁界変調光磁気記録再生装置の構成図。 Figure 9 is a configuration diagram of an optical magnetic field modulation magneto-optical recording and reproducing apparatus.

【符号の説明】 DESCRIPTION OF SYMBOLS

1…保護膜、2…第3磁性膜、3…第2磁性膜、4…第1磁性膜、5…誘電体膜、6…基板、7…記録再生磁界発生装置による磁界、8…初期化磁界、9…光磁気ディスク、10…浮上磁気ヘッド、11…浮上磁気ヘッド駆動装置、12…記録再生制御装置、13…光学ヘッド、 1 ... protective film, 2 ... third magnetic film, 3 ... second magnetic layer, 4 ... first magnetic film, 5 ... dielectric film, 6 ... substrate, 7 ... magnetic field by the recording and reproducing magnetic field generator, 8 ... initialization field, 9 ... optical disk, 10 ... floating magnetic head, 11 ... floating magnetic head driving device, 12 ... recording and playback control unit, 13 ... optical head,
14…スピンドルモーター、15…初期化磁石、16… 14 ... Spindle motor, 15 ... initialization magnet, 16 ...
転写拡大して再生している磁区、17…転写拡大して再生している磁区、18…隣接磁区、19…転写拡大して再生している磁区。 Domains being played by transferring enlarged magnetic domain being played in an enlarged 17 ... transfer, 18 ... adjacent magnetic domains, 19 ... transfer enlarged magnetic domain being played.

Claims (5)

    【特許請求の範囲】 [The claims]
  1. 【請求項1】基板上に少なくとも第1誘電体膜、次に第1、第2、第3磁性層、さらに保護膜を順次積層した光磁気記録媒体において、上記第2磁性層は室温以上に補償温度を有する希土類遷移金属であり、上記第2磁性層のキュリー温度は微小磁区記録温度よりも低いことを特徴とする光磁気記録媒体。 1. A least a first dielectric film on a substrate, then the first, the second, third magnetic layer, the magneto-optical recording medium further sequentially laminated a protective film, the second magnetic layer at room temperature over the the compensation temperature is a rare earth transition metal having a Curie temperature of said second magnetic layer is a magneto-optical recording medium, characterized in that less than minute magnetic domains recorded temperature.
  2. 【請求項2】上記第3磁性層は希土類遷移金属合金からなり、全体の磁気モーメントが希土類の磁気モーメントと室温において同一方向を向いていることを特徴とする請求項1記載の光磁気記録媒体。 Wherein said third magnetic layer is made of rare earth-transition metal alloy, a magneto-optical recording medium according to claim 1, wherein the entire magnetic moment is characterized by being oriented in the same direction in the magnetic moment at room temperature of the rare-earth .
  3. 【請求項3】基板上に少なくとも第1誘電体膜、次に第1、第2、第3磁性層、さらに保護膜を順次積層した光磁気記録媒体を用い、該第1磁性層の側からレーザ光を照射し、その反射光が磁気光学効果を受けることを利用して、情報を再生する装置において、基板側に情報再生手段を、膜側に磁界発生手段を配置し、再生時に磁界および/または再生光を変調して再生する手段を有することを特徴とする光磁気記録再生装置。 Wherein at least a first dielectric film on a substrate, then the first, second, third magnetic layer, further sequentially using an optical magnetic recording medium obtained by laminating a protective film, from the side of the first magnetic layer irradiating a laser beam, the reflected light by utilizing the fact that subjected to magneto-optical effect, the apparatus for reproducing information, the information reproducing means on the substrate side, a magnetic field generating means disposed on the film side, the magnetic field at the time of reproduction and / or magneto-optical recording and reproducing apparatus characterized in that it comprises a means for reproducing by modulating the reproducing light.
  4. 【請求項4】1つの記録ドメインを再生する際に正負の磁界を交番させて再生することを特徴とする請求項3記載の光磁気記録再生装置。 4. One of the magneto-optical recording and reproducing apparatus according to claim 3, wherein the play by alternating magnetic fields of the positive and negative when reproducing the recorded domain.
  5. 【請求項5】1つの記録ドメインを再生する際に正負の磁界を交番させて再生した信号を微分検出することを特徴とする請求項3記載の光磁気記録再生装置。 5. One of the magneto-optical recording and reproducing apparatus according to claim 3, wherein the signal reproduced by the alternating magnetic field of positive and negative differentiating detected when reproducing the recorded domain.
JP14286794A 1994-06-24 1994-06-24 The method of reproducing a magneto-optical recording medium, a magneto-optical recording medium and magneto-optical recording and reproducing apparatus using the same Expired - Fee Related JP3380621B2 (en)

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EP0913818A1 (en) * 1996-07-12 1999-05-06 Hitachi Maxell, Ltd. Magneto-optical recording medium, its reproducing method and reproducer
EP0915462A1 (en) * 1996-07-12 1999-05-12 Hitachi Maxell, Ltd. Magneto-optical recording medium, its reproducing method and reproducer
WO1999034363A1 (en) * 1997-12-25 1999-07-08 Sanyo Electric Co., Ltd. Apparatus for reproducing information and method for reproducing information
WO1999038161A1 (en) * 1998-01-23 1999-07-29 Sanyo Electric Co., Ltd. Reproducing method for magneto-optic recording medium, and magneto-optic disk device
WO1999039341A1 (en) * 1998-01-30 1999-08-05 Hitachi Maxell, Ltd. Optomagnetic recording medium, reproducing method therefor, and reproducing device therefor
US5959942A (en) * 1996-12-17 1999-09-28 Fujitsu Limited Method and apparatus for reading a magneto-optical recording medium with asymmetrical edges
US5982715A (en) * 1997-07-15 1999-11-09 Sharp Kabushiki Kaisha Magneto-optical recording medium having a signal reproducing region of the reproducing layer larger than the record bit in the recording layer
US6031793A (en) * 1997-04-10 2000-02-29 Tdk Corporation Magneto-optical recording medium with a layer to enlarge magnetic domains
US6044044A (en) * 1997-07-04 2000-03-28 Tdk Corporation Magneto-optical recording medium having an enlarged magnetic domain in the amplifier layer during read-out
US6122228A (en) * 1997-08-27 2000-09-19 Hitachi Maxwell, Ltd. Magneto-optical recording medium and reproduction method therefor
US6120921A (en) * 1997-04-10 2000-09-19 Tdk Corporation Magneto-optical recording medium
US6147939A (en) * 1997-03-06 2000-11-14 Sharp Kabushiki Kaisha Magneto-optical recording medium having intermediate layer of in-plane magnetization
US6226234B1 (en) * 1995-12-20 2001-05-01 Hitachi Maxell, Ltd. Magneto-optic recording medium and reproducing method for reproducing magnetic domain in enlarged form on a reproducing layer
US6314061B1 (en) 1998-10-30 2001-11-06 Canon Kabushiki Kaisha Linear high density magneto-optical recording apparatus
US6438073B1 (en) 1998-06-18 2002-08-20 Hitachi Maxell, Ltd. Magnetic lens, magnetic reproducing element, reproducing apparatus and reproducing method
US6477120B1 (en) 1998-11-30 2002-11-05 Sharp Kabushiki Kaisha Magneto-optical recording medium
US6628574B1 (en) 1998-01-12 2003-09-30 Hitachi Maxell, Ltd. Reproducing method and reproducing apparatus using plural light beam powers for transferring a magnetic domain
US7420910B2 (en) 2002-02-06 2008-09-02 Sony Corporation Optical recording/reproducing method for multiple recording media with different recording density

Cited By (28)

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US6226234B1 (en) * 1995-12-20 2001-05-01 Hitachi Maxell, Ltd. Magneto-optic recording medium and reproducing method for reproducing magnetic domain in enlarged form on a reproducing layer
US6385140B2 (en) 1995-12-20 2002-05-07 Hitachi Maxell, Ltd. Magneto-optical recording medium and reproducing method for reproducing magnetic domain in enlarged form on a reproducing layer
EP0913818A1 (en) * 1996-07-12 1999-05-06 Hitachi Maxell, Ltd. Magneto-optical recording medium, its reproducing method and reproducer
US6424601B1 (en) 1996-07-12 2002-07-23 Hitachi Maxell, Ltd. Magneto-optical recording media having an auxiliary magnetic layer
EP0915462A4 (en) * 1996-07-12 2001-09-12 Hitachi Maxell Magneto-optical recording medium, its reproducing method and reproducer
EP0915462A1 (en) * 1996-07-12 1999-05-12 Hitachi Maxell, Ltd. Magneto-optical recording medium, its reproducing method and reproducer
EP0913818A4 (en) * 1996-07-12 2001-04-18 Hitachi Maxell Magneto-optical recording medium, its reproducing method and reproducer
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