JPS63146259A - Magneto-optical recording system - Google Patents
Magneto-optical recording systemInfo
- Publication number
- JPS63146259A JPS63146259A JP29230686A JP29230686A JPS63146259A JP S63146259 A JPS63146259 A JP S63146259A JP 29230686 A JP29230686 A JP 29230686A JP 29230686 A JP29230686 A JP 29230686A JP S63146259 A JPS63146259 A JP S63146259A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnetic
- modulated
- head
- film
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 claims description 7
- 230000003287 optical effect Effects 0.000 abstract description 7
- 230000005415 magnetization Effects 0.000 abstract description 3
- 239000004065 semiconductor Substances 0.000 abstract description 3
- 230000000694 effects Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 238000001514 detection method Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000010287 polarization Effects 0.000 description 2
- 201000009310 astigmatism Diseases 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
Landscapes
- Recording Or Reproducing By Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、光磁気記録装置に係り、特にオーバーライド
に好適な磁界変調方式による光磁気記録方式に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magneto-optical recording device, and particularly to a magneto-optical recording method using a magnetic field modulation method suitable for overwriting.
従来の装置は、特開昭５１−１０７１２１号に記載のよ
うに、レーザ光を磁性膜へ照射すると同時に磁界付与装
置で、変調磁界だけを印加していた。In the conventional apparatus, as described in Japanese Patent Application Laid-open No. 107121/1984, a magnetic field applying device applies only a modulated magnetic field at the same time as a laser beam is irradiated onto a magnetic film.
上記従来技術は、レーザ光を磁性膜に照射するための光
ヘッドに塔載されたレンズアクチュエータ等からの漏洩
磁界について配慮がされておらず、漏洩磁界等により変
調磁界の実効的な値が変化する。The above conventional technology does not take into account the leakage magnetic field from the lens actuator mounted on the optical head for irradiating the magnetic film with laser light, and the effective value of the modulated magnetic field changes due to the leakage magnetic field. do.
また、磁性膜の磁気特性や反磁界などの影響によっても
、記録（または消去）磁界のしきい値（記録または消去
されはじめる磁界の強さ）が磁性膜上で零にならない、
したがって、変ｗＩ４磁界は、記録（または消去）磁界
のしきい値に対してアンバランスな磁界強度となる。上
記漏洩磁界だけでも磁性膜上で１０００ｅ程度にも達し
、高速化および高密度化するための磁気ヘッドの形状や
特性が制限されてしまう、そのため、磁性膜上での実効
磁界が、記録（消去）しきい値以下になったり、わずか
にそのしきい値を上まわる程度となる。このため、安定
な記録および消去が達成できなくなり、記録・消去を同
時に行なう重ね書き（オーバーライド）が不可能となる
問題があった。In addition, the threshold value of the recording (or erasing) magnetic field (the strength of the magnetic field at which recording or erasing begins) may not become zero on the magnetic film due to the magnetic properties of the magnetic film or the influence of the demagnetizing field.
Therefore, the variable wI4 magnetic field has a magnetic field strength that is unbalanced with respect to the threshold value of the recording (or erasing) magnetic field. The above leakage magnetic field alone reaches about 1000 e on the magnetic film, which limits the shape and characteristics of the magnetic head for increasing speed and density. Therefore, the effective magnetic field on the magnetic film is ) below the threshold value or slightly above the threshold value. For this reason, stable recording and erasing cannot be achieved, and there is a problem in that overwriting (overwriting) in which recording and erasing are performed simultaneously is impossible.
本発明の目的は、光ヘッドの７クチユエータ等の漏洩磁
界の影響を取り除き、安定なオーバーライドを可能とす
ることにある。An object of the present invention is to eliminate the influence of leakage magnetic fields from the 7-cut unit of an optical head, etc., and to enable stable override.
上記目的は、光ヘッドに塔載されたレンズアクチュエー
タ等からの漏洩磁界を実質的に取り除くため。The above purpose is to substantially eliminate leakage magnetic fields from lens actuators etc. mounted on the optical head.
磁気ヘッドで漏洩磁界とは逆向きでかつ、同じ大きさの
磁界を発生させ、磁性膜面上での実効磁界が、磁気ヘッ
ドで印加する変調磁界だけにすることにより、達成され
る。This is achieved by generating a magnetic field with the magnetic head in the opposite direction and the same magnitude as the leakage magnetic field, so that the effective magnetic field on the magnetic film surface is limited to the modulated magnetic field applied by the magnetic head.
バイアス磁界と変調磁界を同時に発生させる磁界変調記
録方式は、光ヘッドに塔載されたレンズアクチュエータ
等からの漏洩磁界をオンセルし、記録磁性膜面上に変調
磁界だけが印加される。それによって、確実な記録・消
去が行なわれ、オーバーライドが可能になる。A magnetic field modulation recording method that simultaneously generates a bias magnetic field and a modulation magnetic field turns on the leakage magnetic field from a lens actuator mounted on an optical head, and applies only the modulation magnetic field onto the surface of the recording magnetic film. This ensures reliable recording and erasing and enables overrides.
また、磁界の強度が小さくても安定に記録・消去が行な
える。Further, even if the strength of the magnetic field is small, stable recording and erasing can be performed.
〔実施例〕 以下、本発明の一実施例を第１図により説明する。〔Example〕 An embodiment of the present invention will be described below with reference to FIG.
第１図は、光磁気ディスク装置の構成を示した図である
。半導体レーザ１からの出射光は、カップリングレンズ
２で平行光にされ、偏光ビームスプリッタ３とビーム偏
向用ミラー４を通過して、フォーカスレンズ５で、基板
７ａを透過し記録磁性膜７ｂ上に絞り込まれる。磁性膜
７ｂからの反射光は、偏光ビームスプリッタ３で反射さ
れ、偏光ビームスプリッタ９に導かれる。偏光ビームス
プリッタ９を透過した光は、凸レンズ１３と円柱レンズ
１４からなる非点収差光学系により、光検出器１５に導
かれ、フォーカスエラー検出およびトラックエラー検出
が行なわれる。ここで得られるフォーカスエラー信号は
アクチュエータ６にフィードバックされ、フォーカスレ
ンズ５をその光軸方向に駆動制御し、絞り込まれたレー
ザ光スポットの焦点位置を磁性膜７ｂ上に常に保持する
。また、トラックエラー信号は、ビーム偏光用ミラー４
を駆動制御するアクチュエータにフィードバックされる
。これにより、光スポットは、常に所定のトラックを追
従する。偏光ビームスプリッタ９を反射した光は、偏光
ビームスプリッタ１０に入射する。このとき、偏光ビー
ムスプリッタ１０の直前に２分の１波長板（図示せず）
をそう入して、入射偏光面の角度を４５度にするか、あ
るいは、偏光ビームスプリッタ１０を４５度回転させる
。偏光ビームスプリッタ１０を透過した光は、光検出器
１１に１反射した光は光検出器１２へ導かれ、光検出器
１１と光検出器２の出力の差が光磁気ディスクからの再
生信号となる。FIG. 1 is a diagram showing the configuration of a magneto-optical disk device. The light emitted from the semiconductor laser 1 is made into parallel light by a coupling lens 2, passes through a polarizing beam splitter 3 and a beam deflection mirror 4, and is transmitted through a substrate 7a by a focus lens 5 and onto a recording magnetic film 7b. Narrowed down. The reflected light from the magnetic film 7b is reflected by the polarizing beam splitter 3 and guided to the polarizing beam splitter 9. The light transmitted through the polarizing beam splitter 9 is guided to a photodetector 15 by an astigmatism optical system consisting of a convex lens 13 and a cylindrical lens 14, where focus error detection and tracking error detection are performed. The focus error signal obtained here is fed back to the actuator 6, which drives and controls the focus lens 5 in the direction of its optical axis, so that the focal position of the focused laser beam spot is always maintained on the magnetic film 7b. In addition, the track error signal is transmitted to the beam polarization mirror 4.
is fed back to the actuator that controls the drive. Thereby, the light spot always follows a predetermined track. The light reflected by the polarizing beam splitter 9 enters the polarizing beam splitter 10. At this time, a 1/2 wavelength plate (not shown) is placed immediately before the polarizing beam splitter 10.
, the angle of the incident polarization plane is set to 45 degrees, or the polarizing beam splitter 10 is rotated by 45 degrees. The light transmitted through the polarizing beam splitter 10 is reflected by the photodetector 11, and the light is guided to the photodetector 12. Become.
光磁気記録においては、半導体レーザ１の出力を再生時
より大きくして、ＤＣ的に磁性膜７ｂに光スポットを照
射して照射部の温度を上昇させる。これと同時に、磁気
ヘッド８に記録すべき情報に応じて変調した電流を流し
、変調磁界を磁性膜上に印加する。これにより、変調磁
界の上下向きに応じて、磁性膜の磁化が反転する。この
磁界変調方式を第２図を用いて説明する。第２図で、磁
気ヘッド８から発生される磁界および、磁性膜７ｂ上で
の実効的な磁界を説明する。（ａ）〜（ｄ）の縦軸は、
記録および消去磁界の強さを示し２横軸は時間ｔを示し
た・ （ａ）は、フォーカスレンズ５を駆動するアクチ
ュエータ６が発生し漏洩磁界Ｈａを示す。これは、アク
チュエータ６に組み込れた永久磁石によるもので、常に
一定方向に漏洩している。この状態で変調磁界を印加し
ても、Ｈａを中心に磁界が変調されるため、この場合、
記録を正の磁界と考えると、記録では、漏洩磁界Ｈａだ
け加算された磁界が磁性膜の磁化の向きが決まるが、消
去する場合、漏洩磁界Ｈａが減算された磁界となり、消
去のための磁界が。In magneto-optical recording, the output of the semiconductor laser 1 is made larger than that during reproduction, and a light spot is irradiated onto the magnetic film 7b in a DC manner to raise the temperature of the irradiated portion. At the same time, a current modulated according to the information to be recorded is applied to the magnetic head 8 to apply a modulated magnetic field onto the magnetic film. As a result, the magnetization of the magnetic film is reversed depending on the vertical direction of the modulated magnetic field. This magnetic field modulation method will be explained using FIG. 2. With reference to FIG. 2, the magnetic field generated from the magnetic head 8 and the effective magnetic field on the magnetic film 7b will be explained. The vertical axis of (a) to (d) is
The horizontal axis shows the strength of the recording and erasing magnetic fields.2 The horizontal axis shows time t. (a) shows the leakage magnetic field Ha generated by the actuator 6 that drives the focus lens 5. This is due to the permanent magnet built into the actuator 6, and leakage always occurs in a certain direction. Even if a modulated magnetic field is applied in this state, the magnetic field will be modulated around Ha, so in this case,
Considering recording as a positive magnetic field, in recording, the direction of magnetization of the magnetic film is determined by the magnetic field added by the leakage magnetic field Ha, but when erasing, the leakage magnetic field Ha becomes the magnetic field subtracted, and the magnetic field for erasing but.
不足し、消去が不完全になる。また、漏洩磁界Ｈａが、
負の磁界の場合では、逆に記録が不完全となり、オーバ
ーライドが不可能となる。そこで、（ｂ）に示すように
、漏洩磁界Ｈａとは逆向きで同じ大きさのバイアス磁界
−Ｈａを磁気ヘッド８で、印加する。There will be a shortage and the erasure will be incomplete. In addition, the leakage magnetic field Ha is
Conversely, in the case of a negative magnetic field, recording becomes incomplete and overwriting becomes impossible. Therefore, as shown in (b), a bias magnetic field -Ha having the same magnitude and direction opposite to the leakage magnetic field Ha is applied by the magnetic head 8.
次に、変調磁界１（ｍｏｄｕｌａｔｉｏｎ をバイアス
磁界に重畳させて磁気ヘッド８で印加する。（ｃ）は、
磁気ヘッドで印加する磁界Ｈｓｘｔｅｒｎａｌを示した
。Next, a modulation magnetic field 1 (modulation) is superimposed on the bias magnetic field and applied by the magnetic head 8. (c)
The magnetic field Hsxternal applied by the magnetic head is shown.
ＨｅｘｔａｍａＬ＝ｌｔｗｏｄｕｌａｔｉｏｎ −Ｈａ
−（１，）磁性膜上での実効磁界
１１ｔｏｔａｌを（ｄ）に示す。HextamaL=ltwodulation-Ha
-(1,) The effective magnetic field 11total on the magnetic film is shown in (d).
Ｈｙｏｔａｌ ＝ ＨｅｘｔｅｒｓａＬ ＋ Ｈａ＝
（Ｈｍｏｄｕｌａｔｉｏｎ −Ｈａ ） −Ｈａ＝ｌＩ
ｍｏｄｕｌａｔｉｏｎ −（２）磁界
ヘッドで、バイアス磁界と変調磁界を印加することによ
り、磁性膜上での実効磁界は、磁界の強さ０レベルを中
心に、正負に変調することができ、安定な記録・消去が
可能となる１以上の磁界変調方式による信号レベルと磁
界強度の関係を第３図に示す。Hyotal=HextersaL+Ha=
(Hmodulation -Ha) -Ha=lI
Modulation - (2) By applying a bias magnetic field and a modulation magnetic field with a magnetic field head, the effective magnetic field on the magnetic film can be modulated in positive and negative directions around the 0 level of magnetic field strength, resulting in stable recording. - Figure 3 shows the relationship between signal level and magnetic field strength using one or more magnetic field modulation methods that enable erasing.
第３図（ａ）は、磁気ヘッド印加磁界強度（Ｈａｘｔａ
■ａｔ）による信号レベルを示す、レンズアクチュエー
タ等による漏洩磁界Ｈａにより、磁気ヘッド印加磁界強
度０でも信号レベルが発生する。また、記録しきい値が
−Ｈａとなり、安定な記録・消去を行なうためには、磁
調変界が記録しきい値を中心として印加する必要がある
。（ｂ）は、本発明による実施効果の１例であり、実効
磁界Ｈｔｏｔａｌに対する信号レベルを示しである。磁
界ヘッドでバイアス磁界−Ｈａを印加することにより、
記録しきい値は実効磁界強度がほぼ零となる。これによ
り、変調磁界が実効磁界強度０を中心として印加され、
安定な記録・消去が可能となる。さらに、必要な変調磁
界を小さくすることも可能となる。Figure 3(a) shows the magnetic field strength applied to the magnetic head (Haxta
(2) Due to the leakage magnetic field Ha caused by the lens actuator etc., a signal level is generated even when the magnetic field strength applied to the magnetic head is 0. Further, the recording threshold value is -Ha, and in order to perform stable recording and erasing, it is necessary to apply a magnetic tone changing field centered around the recording threshold value. (b) is an example of the implementation effect of the present invention, and shows the signal level with respect to the effective magnetic field Htotal. By applying a bias magnetic field -Ha with a magnetic field head,
At the recording threshold, the effective magnetic field strength becomes approximately zero. As a result, a modulated magnetic field is applied centered on the effective magnetic field strength of 0,
Stable recording and erasing becomes possible. Furthermore, it is also possible to reduce the required modulation magnetic field.
本発明によれば、レンズアクチュエータからの漏洩磁界
の影響による変調磁界のアンバランスを補正することが
できる。したがって確実な記録・消去ができ、オーバー
ライドが可能となり、転送レートや信頼性が向上する効
果がある。また、磁性膜の反磁界による影響もバイアス
磁界を反磁界の強さに応じて印加することにより、さら
に、安定なオーバーライドができる。さらに、印加する
変調磁界を小さくすることができるため、磁界ヘッドも
小型かつ安価になる。また、同じ印加磁界強度であれば
、磁性膜と磁気ヘッドの間隔を大きくすることができ、
磁気ディスクなどで発生するヘッドクラッシュや磁性膜
の損傷などを防げる効果がある。According to the present invention, it is possible to correct the imbalance of the modulated magnetic field due to the influence of the leakage magnetic field from the lens actuator. Therefore, reliable recording/erasing is possible, overwriting is possible, and the transfer rate and reliability are improved. Moreover, the influence of the demagnetizing field of the magnetic film can be more stably overridden by applying a bias magnetic field according to the strength of the demagnetizing field. Furthermore, since the modulated magnetic field to be applied can be made smaller, the magnetic field head can also be made smaller and less expensive. Also, if the applied magnetic field strength is the same, the distance between the magnetic film and the magnetic head can be increased.
This has the effect of preventing head crashes and damage to the magnetic film that occur in magnetic disks.
第１図は本発明の一実施例を示す光磁気ディスク装置の
構成図、第２図は本発明による磁界変調方式を説明する
ための図、第３図は本発明の一実施例の効果を示す図で
ある。FIG. 1 is a block diagram of a magneto-optical disk device showing an embodiment of the present invention, FIG. 2 is a diagram for explaining a magnetic field modulation method according to the present invention, and FIG. 3 is a diagram showing the effects of an embodiment of the present invention. FIG.
Claims (1)
で記録情報にしたがって磁界を変調して記録する方式に
おいて、該磁気ヘッドによる変調磁界バイアス磁界を印
加することを特徴とする光磁気記録方式。1. Magneto-optical recording in which a recording medium is irradiated with a laser beam in a DC manner, and a magnetic head modulates the magnetic field according to recorded information for recording, which is characterized in that a modulated magnetic field bias magnetic field is applied by the magnetic head. method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61292306A JP2619372B2 (en) | 1986-12-10 | 1986-12-10 | Magneto-optical recording method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61292306A JP2619372B2 (en) | 1986-12-10 | 1986-12-10 | Magneto-optical recording method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63146259A true JPS63146259A (en) | 1988-06-18 |
| JP2619372B2 JP2619372B2 (en) | 1997-06-11 |
Family
ID=17780054
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61292306A Expired - Lifetime JP2619372B2 (en) | 1986-12-10 | 1986-12-10 | Magneto-optical recording method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2619372B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02292755A (en) * | 1989-04-28 | 1990-12-04 | Ricoh Co Ltd | Magneto-optical recorder |
| EP0447617A2 (en) * | 1990-03-08 | 1991-09-25 | Pioneer Electronic Corporation | Optical magnetic recording and reproducing system |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60117403A (en) * | 1983-11-30 | 1985-06-24 | Hitachi Ltd | Photomagnetic head |
| JPH065585A (en) * | 1992-04-22 | 1994-01-14 | Toshiba Corp | Manufacture of semiconductor device |
-
1986
- 1986-12-10 JP JP61292306A patent/JP2619372B2/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60117403A (en) * | 1983-11-30 | 1985-06-24 | Hitachi Ltd | Photomagnetic head |
| JPH065585A (en) * | 1992-04-22 | 1994-01-14 | Toshiba Corp | Manufacture of semiconductor device |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02292755A (en) * | 1989-04-28 | 1990-12-04 | Ricoh Co Ltd | Magneto-optical recorder |
| EP0447617A2 (en) * | 1990-03-08 | 1991-09-25 | Pioneer Electronic Corporation | Optical magnetic recording and reproducing system |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2619372B2 (en) | 1997-06-11 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| EXPY | Cancellation because of completion of term |