【発明の詳細な説明】〔産業上の利用分野〕 本発明は光磁気デイスク用磁界印加薄膜電磁石
に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic field applying thin film electromagnet for a magneto-optical disk.
従来の光磁気記録において記録情報を消去する
場合には、外部磁界を記録時とは逆極性に印加
し、レーザー光ビームを記録時と同等の強度で記
録媒体に一様に照射する、いわゆる一括消去が行
なわれている。即ち外部磁界印加により記録媒体
の磁化状態を記録前の初期状態に戻している。 When erasing recorded information in conventional magneto-optical recording, an external magnetic field is applied with the opposite polarity to that during recording, and a laser beam is uniformly irradiated onto the recording medium with the same intensity as during recording. Erasure is being performed. That is, by applying an external magnetic field, the magnetization state of the recording medium is returned to the initial state before recording.
ここで、公知の外部印磁界加手段は、例えば空
心コイルを用いる方法、電磁石を用いる方法、あ
るいは永久磁石を用いる方法がある。 Here, known external applied magnetic field applying means include, for example, a method using an air-core coil, a method using an electromagnet, or a method using a permanent magnet.
〔発明が解決しようとする問題点〕 前述の磁界印加手段において、記録時と消去時
では通常数100エルステツド以上の印加磁界が必
要であるために、空心コイルを用いる場合には、
コイルが大型化し、これに伴つて、磁界切換速度
が大きいインダクタンスの為に遅くなるととも
に、記録媒体とコイルとの距離を充分に接近させ
ないと所要の印加磁界が得られないという欠点が
ある。また電磁石を用いる場合にも、磁界印加手
段は大型化し、磁界切換速度が大きいインダクタ
ンスの為に遅いという欠点を生じている。さら
に、永久磁石を用いる場合には、機械的な駆動手
段を用いて磁界を切り換える為に複雑な機構が必
要であり、この場合も磁界切換速度は遅いものと
なつている。以上の述べたように、従来のいずれ
の外部磁界印加手段によつても磁界切換速度は遅
いために、消去には上述の一括消去方式が用いら
れ、また記録する時には、一定磁界印加中にレー
ザーパワーを高速変調する方法が用いられてい
る。即ち、従来の装置では既に記録された情報に
新しい情報を高速で重ね書きするいわゆるオーバ
ーライト機能を持たせることが困難であるという
問題点がある。[Problems to be Solved by the Invention] In the above-mentioned magnetic field applying means, an applied magnetic field of several hundred oersted or more is usually required during recording and erasing, so when an air-core coil is used,
As the coil becomes larger, the magnetic field switching speed becomes slower due to the large inductance, and the required applied magnetic field cannot be obtained unless the distance between the recording medium and the coil is sufficiently close. Furthermore, when an electromagnet is used, the magnetic field applying means is large in size and the magnetic field switching speed is slow due to the large inductance. Furthermore, when permanent magnets are used, a complicated mechanism is required to switch the magnetic field using a mechanical drive means, and the magnetic field switching speed is also slow in this case. As mentioned above, the magnetic field switching speed is slow with any conventional external magnetic field application means, so the above-mentioned batch erasing method is used for erasing, and when recording, a laser beam is applied while a constant magnetic field is applied. A method of rapidly modulating power is used. That is, the conventional apparatus has a problem in that it is difficult to provide a so-called overwrite function for rapidly overwriting new information on already recorded information.
本発明の目的は、このような従来の問題点を解
決する為に、大きい磁界の高速スイツチングを可
能にする新規な外部磁界印加手段を提供すること
にある。 SUMMARY OF THE INVENTION An object of the present invention is to provide a novel means for applying an external magnetic field that enables high-speed switching of a large magnetic field in order to solve the problems of the conventional method.
本発明の光磁気デイスク用磁界印加薄膜電磁石
は、光磁気デイスクの両面を挟んで対向し、同一
電流を流す巻線が施され、一方の巻線のコアに中
空部を有する２つの高透磁率磁性体と、この２つ
の高透磁性磁性体を磁気的に接続する高透磁率磁
性体の磁路とを有する光磁気デイスク用磁界印加
電磁石において、前記３つの高透磁率磁性体がそ
れぞれ３つの非磁性基板上に形成された薄膜高透
磁率磁性体であり、前記２つの巻線がそれぞれ高
透磁率磁性体に絶縁層を介してスパイラル状にパ
ターンエツチングにより形成された薄膜コイルで
あることにより構成される。 The magnetic field applying thin film electromagnet for a magneto-optical disk of the present invention has two high magnetic permeability magnets that face each other across both sides of a magneto-optical disk, have windings that conduct the same current, and have a hollow part in the core of one of the windings. In a magnetic field applying electromagnet for a magneto-optical disk, which has a magnetic material and a magnetic path of a high permeability magnetic material that magnetically connects the two high permeability magnetic materials, each of the three high permeability magnetic materials has three high permeability magnetic materials. It is a thin film high permeability magnetic material formed on a non-magnetic substrate, and each of the two windings is a thin film coil formed by pattern etching in a spiral shape on the high permeability magnetic material through an insulating layer. configured.
ここで、薄膜高透磁率磁性体にはスパツタ法に
より形成されたパーマロイ薄膜、センダスト薄
膜、アモルフアス薄膜（CoZr，CoZrNb，
CoTa，CoHfなど）などが考えられ、非磁性基
板にはアルミニウム、チタン、銅、亜鉛などが考
えられる。また、同心円状の中空部を有する一方
の薄膜高透磁率磁性体はレーザ集光用レンズと光
磁気媒体の間に設定し、その中空の内径はレーザ
ビームが通過でき、かつトラツキングによりトラ
ツク方向にレンズが動かせる程度の大きさに設定
される。この中空の周りにスパイラル状にパター
ンエツチングにより形成するコイルには銅又はア
ルミニユームが考えられる。さらにまた、非磁性
基板の表面にはSiO2，Al2O3などの絶縁層を介し
て薄膜高透磁率磁性体が形成される。 Here, the thin film high permeability magnetic material is a permalloy thin film formed by a sputtering method, a sendust thin film, an amorphous thin film (CoZr, CoZrNb,
CoTa, CoHf, etc.), and non-magnetic substrates include aluminum, titanium, copper, zinc, etc. In addition, one of the thin film high permeability magnetic materials having a concentric hollow part is set between the laser condensing lens and the magneto-optical medium, and the inner diameter of the hollow part is such that the laser beam can pass through and the laser beam can be directed in the track direction by tracking. The size is set so that the lens can be moved. The coil formed by pattern etching in a spiral shape around this hollow space may be made of copper or aluminum. Furthermore, a thin film of high permeability magnetic material is formed on the surface of the nonmagnetic substrate via an insulating layer of SiO2 , Al2 O3 or the like.
以下、本発明の実施例について図面を参照して
説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図ａは本発明の一実施例の構成図、第１図
ｂおよびｃはそれぞれ第１図ａの中空部を有する
コイル部分の断面図および第１図ａの中空部を有
しないコイル部分の断面図である。本発明の光磁
気デイスク用磁界印加薄膜電磁石は、薄膜コイル
７が巻かれた円筒状の薄膜高透磁率磁性体９を一
端に有する第２の薄膜高透磁率磁性体２と、この
薄膜コイル７と光磁気デイスク１１を挟んで対向
して設置され、円柱状の中空部２１の周りにパタ
ーンエツチングされたスパイラル状の薄膜コイル
８を一端に有する第１の薄膜高透磁率磁性体１
と、前記第１と第２との薄膜高透磁率磁性体１と
２とを磁気的に結合する第３の薄膜高透磁率磁性
体３と、コイル７と８とに同一の電流を流す磁界
発生電流変調回路１０とから構成される。ここで
第１、第２および第３の薄膜高透磁率磁性体１，
２および３は非磁性基板状に形成される。なお磁
界発生電流変調回路１０により、薄膜コイル７お
よび８へ電流を流すことによつて、記録媒体の垂
直方向への印加磁界が与えられる。また第１、第
２および第３の薄膜高透磁率磁性体１，２および
３は膜厚2μm、長さ数mm〜数10mmのパーマロイ薄
膜が用いられ、またコイル７および８としては、
線幅3μm、高さ3μmの銅膜を微細加工によりスパ
イラル上に積層した巻数数10ターンの銅薄膜コイ
ルが用いられている。また電流値としては数10〜
数100mAが適当である。 FIG. 1a is a block diagram of an embodiment of the present invention, and FIGS. 1b and c are sectional views of a coil portion having a hollow portion in FIG. 1a and a coil portion without a hollow portion in FIG. 1a, respectively. FIG. The magnetic field applying thin film electromagnet for magneto-optical disks of the present invention comprises a second thin film high permeability magnetic material 2 having at one end a cylindrical thin film high permeability magnetic material 9 around which a thin film coil 7 is wound, and this thin film coil 7. and a first thin film high permeability magnetic material 1 which is disposed opposite to each other with the magneto-optical disk 11 in between and has a spiral thin film coil 8 pattern-etched around a cylindrical hollow part 21 at one end.
and a third thin film high permeability magnetic body 3 that magnetically couples the first and second thin film high permeability magnetic bodies 1 and 2, and a magnetic field that causes the same current to flow through the coils 7 and 8. It is composed of a generated current modulation circuit 10. Here, the first, second and third thin film high permeability magnetic bodies 1,
2 and 3 are formed in the shape of non-magnetic substrates. The magnetic field generation current modulation circuit 10 causes current to flow through the thin film coils 7 and 8, thereby applying a magnetic field in the direction perpendicular to the recording medium. The first, second, and third thin film high permeability magnetic bodies 1, 2, and 3 are permalloy thin films with a film thickness of 2 μm and a length of several mm to several tens of mm, and as the coils 7 and 8,
A 10-turn copper thin-film coil is used, which is made by laminating copper films with a line width of 3 μm and a height of 3 μm in a spiral pattern using microfabrication. Also, the current value is several 10~
Several hundred mA is appropriate.
このようにして構成した磁界印加手段では、コ
イルのインダクタンスを10μH以下にすることが
容易なため、薄膜高透磁率磁性体の端面から数mm
離れた位置において数100エルステツドの磁界を、
数ＭHzの高速で切替えることができる。 With the magnetic field applying means configured in this way, it is easy to reduce the inductance of the coil to 10 μH or less, so it can be applied several mm from the end face of the thin film high permeability magnetic material.
A magnetic field of several hundred oersted at a distant position,
It can be switched at a high speed of several MHz.
第２図は第１図の実施例に周辺系を付加した光
磁気記録再生装置の構成図で、この装置により、
光磁気デイスク１１への記録再生・消去を行なつ
た。第２図において磁界発生電流変調回路１０の
出力電流が薄膜コイル７および８に流れ、光磁気
デイスク１１の磁性薄膜１２で構成された記録媒
体に上向き及び下向きの磁界が交互に印加され
る。光磁気記録用ヘツド３１は従来と同様のもの
であり、次のような構成を有する。３２は直線偏
光のレーザ光源であり、例えば半導体レーザが使
用される。３３，３４，３５はビームスプリツタ
である。レーザ光ビーム集光用レンズ３６はアク
チユエータ３７により支持されている。フオーカ
スエラーおよびトラツキングエラー信号はそれぞ
れフオーカスエラー信号検出用受光素子３８，３
９によつてサーボ制御回路４０，４１に入力さ
れ、サーボ信号となり、アクチユエータ３７にフ
イードバツクされる。再生信号は偏光フイルタ４
２を通過後、再生信号検出用受光素子４３によつ
て検出され、再生信号増幅回路４４によつて増幅
される。偏光フイルタ４２としてはグラムトムソ
ンプリズムを用い、再生信号検出用受光素子４３
としてはPINフオトダイオードを用いた。レーザ
光源３２の変調にはレーザ光源変調回路４５が使
用され、記録時、消去時、再生時に合わせてレー
ザ光のパワーが変調される。光磁気デイスクとし
て120mm径のプラスチツク基板上にスパツタ法に
より形成されたSiN上に、さらにスパツタ法によ
りTbFeCo膜を800オングストローム膜に、形成
し、このTbFeCo膜上に再びSiNを形成したデイ
スクを使用した。基板としては予めトラツクピツ
チ1.6μm、深さ700オングストロームの溝が形成
されていわゆるプリグルーブ基板を用いた。 FIG. 2 is a block diagram of a magneto-optical recording and reproducing device in which a peripheral system is added to the embodiment shown in FIG.
Recording, reproduction, and erasing were performed on the magneto-optical disk 11. In FIG. 2, the output current of the magnetic field generation current modulation circuit 10 flows through the thin film coils 7 and 8, and upward and downward magnetic fields are alternately applied to the recording medium composed of the magnetic thin film 12 of the magneto-optical disk 11. The magneto-optical recording head 31 is similar to the conventional one and has the following configuration. 32 is a linearly polarized laser light source, for example, a semiconductor laser is used. 33, 34, and 35 are beam splitters. The laser beam focusing lens 36 is supported by an actuator 37. Focus error and tracking error signals are detected by focus error signal detection light receiving elements 38 and 3, respectively.
9 to the servo control circuits 40 and 41, the signal becomes a servo signal, and is fed back to the actuator 37. The reproduced signal is passed through polarizing filter 4.
2, it is detected by a reproduction signal detection light receiving element 43 and amplified by a reproduction signal amplification circuit 44. A Gram-Thompson prism is used as the polarizing filter 42, and a light receiving element 43 for detecting the reproduced signal is used.
A PIN photodiode was used. A laser light source modulation circuit 45 is used to modulate the laser light source 32, and the power of the laser light is modulated during recording, erasing, and reproduction. As a magneto-optical disk, a TbFeCo film with a thickness of 800 angstroms was formed on SiN formed by a sputtering method on a plastic substrate with a diameter of 120 mm, and a TbFeCo film with a thickness of 800 angstroms was further formed by a sputtering method, and a disk was used in which SiN was again formed on this TbFeCo film. . The substrate used was a so-called pregroove substrate in which grooves with a track pitch of 1.6 μm and a depth of 700 angstroms were formed in advance.
第３図ａ〜ｃは記録の動作モード図である。記
録媒体をキユリー温度以上に上昇できる一定強度
のレーザビームを照射しながら、外部磁界印加の
ための薄膜コイル７，８に第３図ｂに示すような
変調電流を流すことによつて、記録パターンに対
応した外部磁界が印加され、記録媒体の走行に伴
なう冷却過程で印加磁界方向に対応して、第３図
ｃに示すような記録磁化状態が実現される。まず
線速9m／secにてデイスク面上4mWの一定強度
のレーザ光を照射しながら、外部磁界印加手段の
薄膜コイル７，８に1MHzで、200mAの変調電流
を流したところ、良好な記録ができた。この記録
トラツク上に新たに同一条件で記録磁界を0.5M
Hzで印加したところ、この記録磁界に対応した記
録ができ、前に記録した信号の消え残りはみられ
なかつた。 3a to 3c are operation mode diagrams for recording. A recording pattern is created by passing a modulated current as shown in FIG. 3b through the thin film coils 7 and 8 for applying an external magnetic field while irradiating the recording medium with a laser beam of a constant intensity that can raise the temperature above the Curie temperature. An external magnetic field corresponding to the direction of the magnetic field is applied, and a recording magnetization state as shown in FIG. 3c is realized in accordance with the direction of the applied magnetic field during the cooling process as the recording medium runs. First, while irradiating a laser beam with a constant intensity of 4 mW on the disk surface at a linear velocity of 9 m/sec, a modulated current of 200 mA at 1 MHz was passed through the thin film coils 7 and 8 of the external magnetic field applying means, and good recording was obtained. did it. A new recording magnetic field of 0.5M is applied to this recording track under the same conditions.
When applied at Hz, recording corresponding to this recording magnetic field was possible, and no trace of previously recorded signals was observed.
以上述べたように本発明によれば、大きい磁界
の高速スイツチングが可能な光磁気デイスク用外
部磁界印加薄膜電磁石を提供出来る。従つて光磁
気記録再生消去方式では従来の一括消去を必要と
せずに直接所望の記録が可能なオーバライト性能
が実現できるという効果がある。さらに別の効果
として、光ビームが入射する側の薄膜高透磁率磁
性体の一端の中空の周りのコイルはパターンエツ
チングにより作られるために、光磁気デイスクと
のスペーシングをコイル分を無視して設計でき
る。 As described above, according to the present invention, it is possible to provide a thin film electromagnet for applying an external magnetic field for a magneto-optical disk, which is capable of high-speed switching of a large magnetic field. Therefore, the magneto-optical recording/reproducing/erasing method has the effect of realizing overwrite performance that allows desired recording to be performed directly without requiring the conventional batch erasing. Another effect is that because the coil around the hollow at one end of the thin film high permeability magnetic material on the side where the light beam is incident is created by pattern etching, the spacing with the magneto-optical disk is ignored. Can be designed.
第１図ａは本発明の一実施例の構成図、第１図
ｂおよびｃは第１図の２つの薄膜コイル部のそれ
ぞれの断面図、第２図は第１図の実施例を光磁気
デイスク装置に適用した場合の構成図、第３図は
第２図の記録の動作モード図である。 １，２，３，９……薄膜高透磁率磁性体、４，
５，６……非磁性基板、７，８……薄膜コイル、
１０……磁界発生電流変調回路、２１……中空
部、３１……光磁気記録用ヘツド。 FIG. 1a is a block diagram of an embodiment of the present invention, FIGS. 1b and c are sectional views of the two thin film coil parts of FIG. 1, and FIG. FIG. 3 is a configuration diagram when applied to a disk device, and FIG. 3 is an operational mode diagram of the recording shown in FIG. 1, 2, 3, 9... Thin film high permeability magnetic material, 4,
5, 6... Non-magnetic substrate, 7, 8... Thin film coil,
DESCRIPTION OF SYMBOLS 10... Magnetic field generation current modulation circuit, 21... Hollow part, 31... Magneto-optical recording head.
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16927187AJPS6413203A (en) | 1987-07-06 | 1987-07-06 | Thin film electromagnet impressing magnetic field for optical magnetic disk |
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16927187AJPS6413203A (en) | 1987-07-06 | 1987-07-06 | Thin film electromagnet impressing magnetic field for optical magnetic disk |
| Publication Number | Publication Date |
|---|---|
| JPS6413203A JPS6413203A (en) | 1989-01-18 |
| JPH0568763B2true JPH0568763B2 (en) | 1993-09-29 |
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16927187AGrantedJPS6413203A (en) | 1987-07-06 | 1987-07-06 | Thin film electromagnet impressing magnetic field for optical magnetic disk |
| Country | Link |
|---|---|
| JP (1) | JPS6413203A (en) |
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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| US5293360A (en)* | 1989-03-09 | 1994-03-08 | Canon Kabushiki Kaisha | Magnetic field generating device |
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| JP2861188B2 (en)* | 1990-01-31 | 1999-02-24 | ソニー株式会社 | Magneto-optical recording / reproducing device |
| Publication number | Publication date |
|---|---|
| JPS6413203A (en) | 1989-01-18 |
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| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |