JPS61269204A - Magnetic field applying device - Google Patents

Magnetic field applying device

Info

Publication number
JPS61269204A
JPS61269204A JP11074885A JP11074885A JPS61269204A JP S61269204 A JPS61269204 A JP S61269204A JP 11074885 A JP11074885 A JP 11074885A JP 11074885 A JP11074885 A JP 11074885A JP S61269204 A JPS61269204 A JP S61269204A
Authority
JP
Japan
Prior art keywords
magnetic field
magnetic
high permeability
recording
field applying
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
Application number
JP11074885A
Other languages
Japanese (ja)
Inventor
Kaoru Toki
土岐　薫
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
NEC Corp
Original Assignee
NEC Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by NEC Corp filed Critical NEC Corp
Priority to JP11074885A priority Critical patent/JPS61269204A/en
Publication of JPS61269204A publication Critical patent/JPS61269204A/en
Pending legal-status Critical Current

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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

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Recording Or Reproducing By Magnetic Means (AREA)

Abstract

PURPOSE:To execute high speed switching of a large magnetic field by combining a magnetic field applying part consisting of two pieces of permanent magnets, and a high permeability magnetic material to which a winding is performed, and a high permeability magnetic material. CONSTITUTION:The first and the second magnetic field applying parts 2, 3 consisting of plate-shaped permanent magnets 4, 5, and L-type high permeability magnetic materials 6, 7 consisting of a part opposed to one magnetic pole of this permanent magnet and a part having windings 8, 9 are provided symmetrically. In such a case, the magnetic poles to which the high permeability magnetic materials 6, 7 are opposed have the opposite polarity to each other, and the third high permeability magnetic material 10 is provided on a roughly equal position from both these magnetic poles. Also, the windings 8, 9 are connected to a current source.

Description

【発明の詳細な説明】 （産業上の利用分野） 本発明は、レーザ光によって、情報の記録再生消去を行
う光磁気記録再生消去方式などに用いられる外部磁界印
加装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an external magnetic field applying device used in a magneto-optical recording/reproducing/erasing system for recording/reproducing information using a laser beam.

（従来技術とその問題点） 光デイスクメモリは、高密度大容量記録が可能であり、
かつ非接触・高速アクセスもできるという点から、大容
量ファイルメモリの一つとして近年、注目を集めている
。その中でも、記録媒体として、ＭｎＢ１．ＭｎＣｕＢ
１．ＭｎＴｉＢ１．ＭｏＡｚＧｅなどの結晶性磁性薄膜
あるいはＴｂ＋Ｇｄ、Ｄｙ、Ｈｏなどの希土類金属と、
　Ｆｅ、ｃｏ、Ｎｉなどの遷移金属との組み合せによっ
て作成される非晶質磁性薄膜を用いた光磁気ディスクメ
モリは、記録情報の書き替えが可能であるという利点を
有していることから、各所で盛んに研究されている。(Prior art and its problems) Optical disk memory is capable of high-density, large-capacity recording;
It has attracted attention in recent years as a large-capacity file memory because it can also be accessed without contact and at high speed. Among them, MnB1. MnCuB
1. MnTiB1. With a crystalline magnetic thin film such as MoAzGe or a rare earth metal such as Tb+Gd, Dy, or Ho,
Magneto-optical disk memory, which uses an amorphous magnetic thin film created in combination with transition metals such as Fe, Co, and Ni, has the advantage that recorded information can be rewritten, so it is widely used in various places. is being actively researched.

従来、公知の光磁気記録再生消去方式においては情報の
記録・再生・消去に対して、それぞれ次の様な動作がと
られる。記録媒体は、あらかじめ媒体の保磁力以上の外
部磁界により一方向に着磁される。記録にはレーザ光に
より発生する熱を利用する。レーザ光ビームを１〜２μ
ｍψの微小スポットに絞って、記録媒体に照射し、媒体
温度を上昇させる。キューり温度記録の場合には、記録
媒体をキューリ温度以上に上昇させ、外部印加磁界ある
いは記録媒体の反磁界によって、反転磁区を形成する。In conventionally known magneto-optical recording, reproducing and erasing systems, the following operations are performed for recording, reproducing and erasing information. The recording medium is magnetized in one direction in advance by an external magnetic field having a coercive force greater than or equal to the coercive force of the medium. Recording uses heat generated by laser light. Laser light beam 1~2μ
The recording medium is irradiated to a minute spot of mψ to raise the temperature of the medium. In the case of Curie temperature recording, the recording medium is heated above the Curie temperature, and reversal magnetic domains are formed by an externally applied magnetic field or a demagnetizing field of the recording medium.

補償温度記録の場合には、記録媒体の補償温度を室温付
近に設定し、レーザ光ビーム照射によって、ある温度ま
で昇温させた時の媒体保磁力低下を利用し、外部印加磁
界によって反転磁区を形成する。これらの手段により、
記録２値信号ｆ’ｘＪ　ｒＯＪを記録媒体の反転磁区の
有無に対応した形で記録できる。In the case of compensated temperature recording, the compensation temperature of the recording medium is set near room temperature, and by utilizing the decrease in coercive force of the medium when the temperature is raised to a certain temperature by irradiation with a laser beam, the reversal magnetic domain is changed by an externally applied magnetic field. Form. By these means,
The recording binary signal f'xJ rOJ can be recorded in a form corresponding to the presence or absence of reversed magnetic domains in the recording medium.

再生は磁気光学効果（Ｋｅｒｒ効果又は、Ｆａｒａｄａ
ｙ効果）を用いて行なわれる。即ち、記録媒体の反転磁
区の有無に対応して、媒体からの反射光あるいは透過光
の偏光面が回転することを利用して、記録媒体から情報
を読み出す。記録媒体には記録時にくらべ低パワーレベ
ルのレーザ光が照射されその反射光または透過光から信
号を再生する。Reproduction is based on the magneto-optical effect (Kerr effect or Farada effect).
y effect). That is, information is read from the recording medium by utilizing the fact that the plane of polarization of reflected light or transmitted light from the medium rotates depending on the presence or absence of reversed magnetic domains in the recording medium. A recording medium is irradiated with laser light at a lower power level than during recording, and a signal is reproduced from the reflected or transmitted light.

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。When erasing recorded information, an external magnetic field is applied with a polarity opposite to that during recording, and a laser beam is uniformly irradiated onto the recording medium with the same intensity as during recording.

いわゆる一括消去が行われる。この過程で、記録媒体の
磁化状態は記録前の初期状態に戻る。So-called batch erasing is performed. In this process, the magnetization state of the recording medium returns to the initial state before recording.

ここで、公知の外部磁界印加手段としては、空心コイル
、電磁石あるいは永久磁石が知られている。Here, air-core coils, electromagnets, or permanent magnets are known as known external magnetic field applying means.

しかしながら、記録時と消去時では、通常数百エルステ
ッ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って、磁界切
り替え速度が遅くなると共に、記録媒体とコイルとの距
離を十分に接近させないと所要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り替え速度が遅いという欠点
を生じる。さらに、永久磁石を用いる場合は、磁界切り
替えに、機械的駆動手段を用いる必要があるため、その
機構は複雑化し、又この場合も、磁界切り替え速度は遅
いものとなる。However, when recording and erasing, an applied magnetic field of several hundred oersteds or more is usually required, so when using an air-core coil, the coil becomes larger, which slows down the magnetic field switching speed, and the recording medium The disadvantage is that the required applied magnetic field cannot be obtained unless the distance between the coil and the coil is sufficiently close. Furthermore, when an electromagnet is used, the magnetic field applying means becomes large and the magnetic field switching speed is slow. Furthermore, when permanent magnets are used, it is necessary to use a mechanical drive means to switch the magnetic field, which complicates the mechanism, and also in this case, the magnetic field switching speed becomes slow.

以上述べた様に、従来のいずれの方式においても、数百
エルステッド以上の磁界を、高速で切り替えることは困
難である。従って消去には、上述した一括消去方式が用
いられ、また記録には、一定磁界印加中に、レーザパワ
ーを高速変調する方法が用いられていた。すなわち、従
来装置では、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、いわゆるオーバライド性能を持たせる
ことは不可能であった。As described above, in any of the conventional methods, it is difficult to switch a magnetic field of several hundred oersted or more at high speed. Therefore, for erasing, the above-mentioned batch erasing method has been used, and for recording, a method has been used in which the laser power is modulated at high speed while a constant magnetic field is applied. That is, with conventional devices, it has been impossible to provide so-called override performance, in which new information is overwritten at high speed on already recorded information.

（発明の目的） 本発明の目的は、この様な問題点を解決するために成さ
れたものであり、大きな磁界の高速スイッチングが可能
な新規な外部磁界印加装置を提供することによって、光
磁気記録再生消去装置の記録消去特性を改善させること
にある。(Objective of the Invention) The object of the present invention was to solve such problems, and by providing a novel external magnetic field applying device capable of high-speed switching of a large magnetic field, The object of the present invention is to improve the recording/erasing characteristics of a recording/reproducing/erasing device.

（発明の構成） 本発明の構成は、磁界印加手段において、第１の永久磁
石と、そのＮ極に対向する部分及び巻線が施こされた部
分を少なくとも有する第１の高透磁率磁性体とから成る
＠１の磁界印加部分と、第２の永久磁石と、そのＳ極に
対向する部分及び巻線が施こされた部分を少なくとも有
する第２の高透磁率磁性体とから成る第２の磁界印加部
分とが前記第１．第２の永久磁石のＮ極とＳ極とが近接
する様に配置され、さらにこれら２つの磁極から、ほぼ
等しい位置に、第３の高透磁率磁性体が配設されたこと
を特徴とする。(Structure of the Invention) The structure of the present invention is that the magnetic field applying means includes a first permanent magnet, a first high permeability magnetic body having at least a portion facing the N pole thereof and a portion on which a winding is applied. A second magnetic field application part @1 consisting of a second permanent magnet and a second high permeability magnetic body having at least a part facing the S pole of the second permanent magnet and a part on which a winding is applied. The magnetic field application portion is the first magnetic field application portion. The N pole and S pole of the second permanent magnet are arranged close to each other, and a third high magnetic permeability magnetic body is arranged at approximately the same position from these two magnetic poles. .

（構成の詳細な説明） 次に、本発明の構成例について、図面を用いて詳細に説
明する、第１図は本発明ｌこ係る磁界印加装置１の構成
を示した図である。図によれば、板状の永久磁石４，５
と、この永久磁石の一方の磁極に対向する部分と巻線８
．９を有する部分とから成るＬｍの高透磁率磁性体６．
７とから成る第１及び第２の磁界印加部分２．３が対称
に配設され、さらに、前記高透磁率磁性体６．７が対向
した磁極は、互いに逆極性であり、これらの両磁極から
ほぼ等しい位置ｔこ、第３の高透磁率磁性体ｌＯが配設
されている。さらに巻線８，９は、電流源に接続されて
いる。第２図（ａ）　、　（ｂ）　、　（Ｃ）を用いて
本構成の動作を説明する。(Detailed Description of Configuration) Next, a configuration example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of a magnetic field application device 1 according to the present invention. According to the figure, plate-shaped permanent magnets 4, 5
and the part facing one magnetic pole of this permanent magnet and the winding 8
．． 6. Lm high permeability magnetic body consisting of a portion having 9.
The first and second magnetic field applying portions 2.3 consisting of At approximately the same position from t, a third high permeability magnetic body 10 is disposed. Furthermore, the windings 8, 9 are connected to a current source. The operation of this configuration will be explained using FIGS. 2(a), (b), and (C).

巻線８及び９のいずれにも電流が流れていない時は、第
２図（ａｌに示す様に、高透磁率磁性体６及び７は、永
久磁石４及び５の磁極から生じる磁束】１及び１２をそ
れぞれ、もう一方の磁極へ効率良く導く磁路を形成する
ため、これらの下方へは磁界が殆ど印加されない。第２
図（ｂ）に示す様に、第１の巻線８だけ齋こ電流が流れ
る場合、電流Ｉによって、第１の高透磁率磁性体６内に
生じる磁束の分だけ、永久磁石４の磁極から磁束が外部
に漏れるため、その下方へ、バイアス磁界が印加される
様になる。この磁界により、第３の高透磁率磁性体１０
は下向きに磁化され、さらにこの磁化から下方の垂直方
向へバイアス磁界が印加される様になる。第３図は、巻
線電流工と、上記バイアス磁界ＨＢとの関係を示したも
のである。バイアス磁界ＨＢは、電流工の増加に伴って
増加し、高透磁率磁性体６内の磁化が飽和に近づくにつ
れて、飽和する傾向を示し、電流値工Ｓ以上では、第１
の高透磁率磁性体が存在しない場合と、同等の大きい値
となる。同様にして、巻線９だけに電流が流れる場合に
は、第２図（Ｃ）に示す様に、第３の高透磁率磁性体１
０の下方には、第２図（ａ）とは逆向き、すなわち上向
きのバイアス磁界が発生する。この様に、巻線８．９へ
流す電流を調整することによって第３の高透磁率磁性体
の下方部分には、望む方向に垂直磁界を発生することが
できる。When no current flows through either of the windings 8 and 9, as shown in FIG. In order to form a magnetic path that efficiently guides each of 12 to the other magnetic pole, almost no magnetic field is applied below these.
As shown in Figure (b), when the current flows only in the first winding 8, the magnetic flux generated in the first high permeability magnetic body 6 due to the current I is removed from the magnetic pole of the permanent magnet 4. Since the magnetic flux leaks to the outside, a bias magnetic field is applied below it. This magnetic field causes the third high permeability magnetic body 10
is magnetized downward, and from this magnetization a bias magnetic field is applied in the downward perpendicular direction. FIG. 3 shows the relationship between the winding current and the bias magnetic field HB. The bias magnetic field HB increases as the current value increases, and tends to become saturated as the magnetization within the high permeability magnetic material 6 approaches saturation.
The value is as large as when no high permeability magnetic material exists. Similarly, when current flows only through the winding 9, as shown in FIG. 2(C), the third high permeability magnetic body 1
Below 0, a bias magnetic field is generated in the opposite direction to that shown in FIG. 2(a), that is, in an upward direction. In this manner, by adjusting the current flowing through the winding 8.9, a perpendicular magnetic field can be generated in the desired direction in the lower portion of the third high permeability magnetic body.

ここで、永久磁石４．５としては厚さ数ミリメートル、
幅及び長さが数ミリ−数十数ミリメートルマリウムコバ
ルト磁石や、アルニコ磁石もしくはフェライト磁石が用
いられ、高透磁率磁性体６゜７．１０としては、厚さ数
ミリメートル、磁路長及び幅が数ミリ−数十ミ数ミリメ
ートルケル・鉄合金もしくは、Ｎ　ｉ　７．　ｎフェラ
イｔ−ＰＭｎＺｎフェライト等のソフトフェライトが用
いられる。又巻線８゜９としては、線径数十ミクロン−
数百ミクロンの銅線が用いられ、巻数は数十ターンであ
り、電流値工ｓとしては、数十〜数百ミリアンペアが追
歯である。第１及びＮ２の磁界印加部分２及び３．及び
第３の高透磁率磁性体は、互いに数百ミクロン−数ミリ
離れた位置に配設される。この様にして構成した磁界印
加装置では、巻線のインダクタンスＬを、数十μＨ以下
にすることが容易である。Here, the permanent magnet 4.5 has a thickness of several millimeters,
Marium cobalt magnets, alnico magnets, or ferrite magnets with widths and lengths ranging from several millimeters to several tens of millimeters are used, and high magnetic permeability magnetic materials 6°7.10 have a thickness of several millimeters and magnetic path lengths and widths of Several millimeters to tens of millimeters Kel-iron alloy or Ni 7. Soft ferrite such as n-ferrite, t-PMnZn ferrite, etc. is used. Also, for the winding wire 8°9, the wire diameter is several tens of microns.
A copper wire of several hundred microns is used, the number of turns is several tens of turns, and the current value is several tens to several hundred milliamperes. First and N2 magnetic field application portions 2 and 3. and the third high magnetic permeability magnetic body are arranged at positions separated from each other by several hundred microns to several millimeters. In the magnetic field applying device configured in this manner, the inductance L of the winding can be easily reduced to several tens of μH or less.

従って、数百エルステッドオーダの垂直磁界を、数メガ
へルツオーダで、切替えることが第３の高透磁率磁性体
１０から数ミリメートル離れた位置において実現できる
。Therefore, it is possible to switch a vertical magnetic field on the order of several hundred oersteds to several megahertz order at a position several millimeters away from the third high permeability magnetic body 10.

本構成の主要部を成す第１もしくはＷＪ２の磁界印加部
分２．３の構成には抛々のものが考えられる。There are many possible configurations for the magnetic field applying portion 2.3 of the first or WJ2, which constitutes the main part of this configuration.

第４図〜第７図は、この部分の他の構成例１５，１９゜
２３．２７を示す図である。FIGS. 4 to 7 are diagrams showing other configuration examples 15, 19° 23.27 of this part.

第４図では、高透磁率磁性体１７において、巻ｌｌ１１
８が施こされた部分の幅が、永久磁石１６の磁極に対向
する部分より小さいことを特徴とする。In FIG. 4, in the high permeability magnetic material 17, the winding ll11
The width of the part where 8 is applied is smaller than the part facing the magnetic pole of the permanent magnet 16.

第５図では、高透磁率磁性体２１において、巻線２２が
施こされた部分の厚みが、永久磁石２０の磁極に対向す
る部分より小さいことを特徴とする。In FIG. 5, the high permeability magnetic body 21 is characterized in that the thickness of the portion where the winding 22 is applied is smaller than that of the portion facing the magnetic pole of the permanent magnet 20.

第６図では、高透磁率磁性体２５において、巻線２６が
施こされた部分の幅及び厚み共に、永久磁石２４の磁極
に対向する部分より小さいことを特徴とする。In FIG. 6, the high permeability magnetic body 25 is characterized in that both the width and thickness of the portion where the winding wire 26 is applied are smaller than the portion facing the magnetic pole of the permanent magnet 24.

これらの構成例は、いずれも第１図に示す構成例に比べ
て、巻線部の高透磁率磁性体の断面積を小さくすること
によって、より低い電流値で、巻線部の磁化が飽和する
様にでき、その結果、印加磁界の高速切り替えを容易に
するものである。In each of these configuration examples, compared to the configuration example shown in Figure 1, by reducing the cross-sectional area of the high permeability magnetic material in the winding part, the magnetization of the winding part is saturated at a lower current value. As a result, it is possible to easily switch the applied magnetic field at high speed.

第７図では、高透磁率磁性体２９がＵ型をしており、こ
のため、永久磁石２８の磁極から発生する磁束を、上記
の構成例より効率良く、もう一方の磁極に導くことがで
きるので、巻線３０に通電しない時に、印加磁界を、よ
り完全に庶蔽できる。In FIG. 7, the high magnetic permeability magnetic body 29 has a U-shape, and therefore the magnetic flux generated from the magnetic pole of the permanent magnet 28 can be guided to the other magnetic pole more efficiently than in the above configuration example. Therefore, when the winding 30 is not energized, the applied magnetic field can be more completely suppressed.

以上、磁界印加部分の構成として、高透磁率磁性体がＬ
型、Ｕ型のものについて述べたが、この構成に限らず、
少なくとも永久磁石の磁極の一方に対向する部分及び巻
線が施こされた部分を有するものであれば良い。As mentioned above, as the configuration of the magnetic field application part, the high magnetic permeability magnetic material is L
Although we have described the U-shaped and U-shaped configurations, the configuration is not limited to this configuration.
Any material may be used as long as it has at least a portion facing one of the magnetic poles of the permanent magnet and a portion provided with a winding.

（実施例） 第８図に示す様に、光磁気ディスク４７の両側に、光磁
気記録用ヘッドと磁界印加手段ｌを配した光磁気記録再
生消去装置を用いて、光磁気ディスクへの情報記録・再
生・消去を行なった。外部磁界印加手段ｌの第１及び第
２の磁界印加部分ＡＢとしては、第６図に示したものを
用いた。これらは、永久磁石としては、厚さ２■幅及び
高さ３０諺のアルニコ磁石を用い、第１及び第２の高透
磁率磁性体としては、Ｍ　ｎ　７．　ｎフェライトを磁
極に対向する部分が、厚さ２■幅３５ｍに、巻線部が厚
さ１■高さ１０■に成形したものを用い、この両者を接
着剤で接着したものから成る。磁界印加部分Ａ及びＢは
、２■の間隔と隔てて、平行に配設され、これらから１
諺隔れた位置に、ＭｎＺｎフェライトから成り、厚み３
ｍ、幅２０■高さ１０ｍの第３の高透磁率磁性体が配設
されている。(Example) As shown in FIG. 8, information is recorded on a magneto-optical disk using a magneto-optical recording/reproducing/erasing device having a magneto-optical recording head and a magnetic field applying means l arranged on both sides of a magneto-optical disk 47. - Played/deleted. As the first and second magnetic field applying portions AB of the external magnetic field applying means 1, those shown in FIG. 6 were used. As the permanent magnet, an alnico magnet with a thickness of 2 mm and a width of 30 mm is used, and as the first and second high permeability magnetic materials, M n 7. The part facing the magnetic pole is formed of n-ferrite with a thickness of 2 mm and a width of 35 m, and the winding part is formed with a thickness of 1 mm and a height of 10 mm, and both are bonded together with an adhesive. The magnetic field application parts A and B are arranged parallel to each other with an interval of 2cm apart, and 1.
Made of MnZn ferrite, with a thickness of 3
A third high permeability magnetic body with a width of 20 m, a width of 20 m and a height of 10 m is disposed.

光磁気記録用ヘッド３１は、従来と同等のものであり、
次の様な構成を有する。３３は直線偏向のレーザ光源で
あり、例えば半導体レーザが使用される。３４，３５．
３６はビームスプリッタである。The magneto-optical recording head 31 is the same as the conventional one,
It has the following configuration. 33 is a linearly polarized laser light source, for example, a semiconductor laser is used. 34, 35.
36 is a beam splitter.

レーザ光ビーム集光用レンズ３７は、アクチュエータ３
８により支持されている。フォーカスエラーならびにト
ラッキングエラー信号は、それぞれフォーカスエラー検
出用受光素子３９．トラッキングエラー検出用受光素子
４０によって検出され、サーボ制御回路４１．４２に入
力され、サーボ信号となり、前記アクチュエータ３８に
フィードバックされる。再生信号は偏光フィルタ４３を
通過後再生信号検出用受光素子４４によって検出され、
再生信号増幅回路４５によって増幅される。偏光フィル
タ４３としては、たとえば、ダラムトムソンプリズムが
用いられる。再生信号検出用受光素子４４と１７は、た
とえばＰＩＮフォトダイオードまたはアバランシェ・フ
ォトダイオードが使用される。レーザ光源３３の変調に
は、レーザ光源変調用回路が使用され、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。The laser beam focusing lens 37 is connected to the actuator 3
8. The focus error and tracking error signals are sent to the focus error detection light receiving element 39. It is detected by the tracking error detection light receiving element 40, input to the servo control circuits 41 and 42, becomes a servo signal, and is fed back to the actuator 38. The reproduced signal passes through a polarizing filter 43 and is detected by a reproduced signal detection light receiving element 44.
The reproduced signal amplification circuit 45 amplifies the signal. As the polarizing filter 43, for example, a Durham Thomson prism is used. For example, a PIN photodiode or an avalanche photodiode is used as the reproduced signal detection light receiving elements 44 and 17. A laser light source modulation circuit is used to modulate the laser light source 33.
The power of the laser beam is modulated in accordance with the reproduction.

光磁気ディスク４７と１７は、１２００φのプラスチッ
ク基板上に、スパッタ法により’ｌ’ｂｐｅ膜を８０Ｏ
Ａ厚に、形成したディスクを使用した。基板としては、
あらかじめ幅０．８μｍ、ピッチ２．５μｍ、深さ７０
０Ａの溝が形成されている、プリグループ基板を用いた
。The magneto-optical disks 47 and 17 are made by sputtering an 80O
A disk formed to a thickness of A was used. As a substrate,
Width 0.8 μm, pitch 2.5 μm, depth 70 in advance
A pre-group substrate in which a 0A groove was formed was used.

第９図（ａ）　、　（ｂ）　、　（Ｃ）　、　（ｄ）に
、記録の動作モード図を示す。記録媒体をキューリ一温
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
がら外部磁界印加手段Ａ及びＢの巻線に、それぞれＩＪ
びＩＢの変調電流を交互に流すことによって、記録パタ
ーンに対応した外部磁界が印加され、記録媒体の走向に
伴う冷却過程で、印加磁界方向に対応して第９図（ｄ）
に示す様な記録磁化状態が実現される。FIGS. 9(a), (b), (C), and (d) show recording operation mode diagrams. IJ is applied to the windings of external magnetic field applying means A and B while irradiating a laser beam with a constant intensity capable of raising the recording medium to a temperature above one Curie.
By alternately passing the modulated currents of I and IB, an external magnetic field corresponding to the recording pattern is applied, and during the cooling process accompanying the strike of the recording medium, the magnetic field changes as shown in FIG. 9(d) in accordance with the direction of the applied magnetic field.
A recorded magnetization state as shown in is realized.

まず、線速９　ｗｒ／　Ｓ　ｅ　Ｃにて、ディスク面上
４ｍＷの一定強度レーザ光を照射しながら、外部磁界印
加手段の巻線Ａ及びＢに、ＩＭＨ２で、２００ｍＡの変
調電流を流したところ、良好な記録ができた。First, while irradiating the disk surface with a constant intensity laser beam of 4 mW at a linear velocity of 9 wr/Sec, a modulated current of 200 mA was applied to the windings A and B of the external magnetic field application means at IMH2. , a good record was made.

この記録トラック上に、新たに、同一条件で、記録磁界
を０．５ＭＨｚで印加したところ、この記録磁界に対応
した記録ができた。そして、前に記録した信号の消え残
りは見られず、オーバライドが実現できた。When a recording magnetic field of 0.5 MHz was newly applied to this recording track under the same conditions, recording corresponding to this recording magnetic field was completed. There was no trace of the previously recorded signal remaining, and overriding was possible.

本発明の適用は、これに限らず大きい磁界の高速スイッ
チングを要求される分野に、同様に適用できる。又、従
来の光磁気記録方式における磁界印加装置としても用い
られることは、言うまでもない。また第１図で２つの永
久磁石はそれぞれの２つの磁極が互いに対向するように
平行に配置されているが、少なくとも２つの永久磁石は
それぞれの高透磁率磁性体と対向する磁極が互いに近接
するようｌと配置されていれば、他の配置をとってもか
まわない。Application of the present invention is not limited to this, but can be similarly applied to fields that require high-speed switching of large magnetic fields. It goes without saying that it can also be used as a magnetic field applying device in conventional magneto-optical recording systems. In addition, in Figure 1, the two permanent magnets are arranged in parallel so that their two magnetic poles face each other, but at least two permanent magnets have magnetic poles facing each high permeability magnetic body close to each other. Other arrangements may be used as long as they are arranged accordingly.

（発明の効果） 以上述べた様に、本発明によれば大きい磁界の高速スイ
ッチングが可能な、外部磁界印加装置を提供できる１、
従って本発明を用いた光磁気記録・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
可能なオーバーライド性能が実現できる。(Effects of the Invention) As described above, according to the present invention, an external magnetic field applying device capable of high-speed switching of a large magnetic field can be provided.
Therefore, the magneto-optical recording/reproducing/erasing method using the present invention can achieve override performance that enables direct desired recording without requiring conventional batch erasing.

【図面の簡単な説明】[Brief explanation of drawings]

第１図、第４図〜第７図は、本発明の構成例を示す図、
第２図（ａ）　、　（ｂ）　、　（Ｃ）第３図は、本発
明の詳細な説明する図、第８図は本発明の実施例を示す
図、第９図（ａ）　、　（ｂＪ　、　（Ｃ）　、　（ｄ
）は本発明の実施例の動作モード図である。 図において、１・−磁界印加手段、２，３，１５，１９
，２３．２７・・・磁界印加部分、４，５，１６，２０
，２４．２８・・・永久磁石、６．７，１０，１７，２
１，２５．２９・・・高透磁率磁性体、８，９．１８，
２２゜２６．３０−・・巻線、１１，１２，１３．１４
・・・磁束、３１・−光磁気記録用ヘッド、３２−・電
流源、３３−・・レーザ光源３４．３５．３６・・・ビ
ームスプリッタ、３７・・・レーザビーム集光用レンズ
、３８・・・アクチュエータ、３９．４０・・・エラー
検出用受光素子、４１．４２−サーボ制御回路、４３−
・・偏光フィルタ、４４・−再生信号検出用受光素子、
４５・−増幅回路、４６−・レーザ光源変調用回路、４
７・−光磁気ディスク、４８・・・記録媒体、４９−記
録媒体走向方向、５０・・・記録磁化である。 第１図 第　６　図 男　９　図 ｗ 巳 記領ｉ差化１欠蒐。1, 4 to 7 are diagrams showing configuration examples of the present invention,
2(a), (b), (C) FIG. 3 is a diagram explaining the present invention in detail, FIG. 8 is a diagram showing an embodiment of the present invention, FIG. 9(a), (bJ , (C) , (d
) is an operation mode diagram of an embodiment of the present invention. In the figure, 1 - magnetic field applying means, 2, 3, 15, 19
, 23.27...Magnetic field application part, 4, 5, 16, 20
,24.28...Permanent magnet, 6.7,10,17,2
1,25.29...High permeability magnetic material, 8,9.18,
22゜26.30--Winding, 11, 12, 13.14
...Magnetic flux, 31.-Magneto-optical recording head, 32-.Current source, 33-.Laser light source 34.35.36..Beam splitter, 37..Lens for laser beam focusing, 38. ...Actuator, 39.40... Light receiving element for error detection, 41.42-Servo control circuit, 43-
・・Polarizing filter, 44・− Light receiving element for detecting reproduced signal,
45--amplification circuit, 46--laser light source modulation circuit, 4
7 - magneto-optical disk, 48 - recording medium, 49 - recording medium running direction, 50 - recording magnetization. Figure 1, Figure 6, Man, Figure 9, w, Snake Territory i, Differential 1 missing.

Claims (1)

【特許請求の範囲】[Claims] 第１の永久磁石とそのＮ極に対向する部分及び巻線が施
こされた部分を少なくとも有する第１の高透磁率磁性体
とから成る第１の磁界印加部分と第２の永久磁石とその
Ｓ極に対向する部分及び巻線が施こされた部分を少なく
とも有する第２の高透磁率磁性体とから成る第２の磁界
印加部分とが前記第１、第２の永久磁石のＮ極とＳ極と
が近接する様に配置され、さらにこれら２つの磁極から
、ほぼ等しい位置に、第３の高透磁率磁性体が配置され
たことを特徴とする磁界印加装置。A first magnetic field application portion consisting of a first permanent magnet, a first high permeability magnetic body having at least a portion facing the N pole thereof and a portion provided with a winding; a second permanent magnet; A second magnetic field applying portion comprising a second high magnetic permeability magnetic body having at least a portion facing the S pole and a portion having a winding wire is connected to the N pole of the first and second permanent magnets. A magnetic field applying device characterized in that the S pole is arranged in close proximity to the S pole, and further, a third high magnetic permeability magnetic body is arranged at approximately the same position from these two magnetic poles.
JP11074885A 1985-05-23 1985-05-23 Magnetic field applying device Pending JPS61269204A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP11074885A JPS61269204A (en) 1985-05-23 1985-05-23 Magnetic field applying device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP11074885A JPS61269204A (en) 1985-05-23 1985-05-23 Magnetic field applying device

Publications (1)

Publication Number Publication Date
JPS61269204A true JPS61269204A (en) 1986-11-28

Family

ID=14543547

Family Applications (1)

Application Number Title Priority Date Filing Date
JP11074885A Pending JPS61269204A (en) 1985-05-23 1985-05-23 Magnetic field applying device

Country Status (1)

Country Link
JP (1) JPS61269204A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1533817A2 (en) * 2003-11-18 2005-05-25 Tandberg Data Storage A/S Magnetic recorder head and method for high coercivity media employing concentrated stray magnetic fields

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1533817A2 (en) * 2003-11-18 2005-05-25 Tandberg Data Storage A/S Magnetic recorder head and method for high coercivity media employing concentrated stray magnetic fields
EP1533817A3 (en) * 2003-11-18 2007-07-11 Tandberg Data Storage A/S Magnetic recorder head and method for high coercivity media employing concentrated stray magnetic fields
US7492550B2 (en) 2003-11-18 2009-02-17 Tandberg Storage Asa Magnetic recording head and method for high coercivity media, employing concentrated stray magnetic fields

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