JPS61187101A - Magnetic field impressing device - Google Patents
Magnetic field impressing deviceInfo
- Publication number
- JPS61187101A JPS61187101A JP2711285A JP2711285A JPS61187101A JP S61187101 A JPS61187101 A JP S61187101A JP 2711285 A JP2711285 A JP 2711285A JP 2711285 A JP2711285 A JP 2711285A JP S61187101 A JPS61187101 A JP S61187101A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnetic
- magnet
- current
- core part
- 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
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
Description
【発明の詳細な説明】
(産業上の利用分野)
本発明は、大きい磁界を高速でスイッチングできる磁界
印加装置に関する。DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a magnetic field application device capable of switching a large magnetic field at high speed.
(従来技術とその問題点)
たとえば従来の光磁気記録においては記録情報を消去す
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、いわゆる一括消去が行われる口外部磁界印加
により記録媒体の磁化状態は記録前の初期状態に戻る。(Prior art and its problems) For example, in conventional magneto-optical recording, when erasing recorded information, an external magnetic field is applied with the opposite polarity to that during recording, and a laser beam is used to record with the same intensity as during recording. The magnetization state of the recording medium returns to the initial state before recording by applying an external magnetic field that uniformly irradiates the medium, which performs so-called batch erasing.
ここで、公知の外部磁界印加手段は、たとえば空心コイ
ルを用いる方法、電磁石を用いる方法。Here, known external magnetic field applying means include, for example, a method using an air-core coil and a method using an electromagnet.
あるいは永久磁石を用いる方法である〇しかしながら、
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。Alternatively, there is a method using a permanent magnet〇However,
This is because an applied magnetic field of several hundred oersted or more is usually required during recording and erasing.
空心コイルを用いる場合には、コイルが大型化し。When using an air-core coil, the coil becomes larger.
これに伴って、磁界切換え速度が遅くなると共K。Along with this, the magnetic field switching speed becomes slower.
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。There is a drawback that the required applied magnetic field cannot be obtained unless the distance between the recording medium and the coil is made sufficiently close.
また、電磁石を用いる場合にも、磁界印加手段は大盤化
し、磁界切換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1機械的な駆動手段を用いて
磁界を切換えるため複雑な機構が必要であシ、この場合
も磁界切替速度は遅いものとなる。In addition, when using an electromagnet, the magnetic field applying means is large and the magnetic field switching speed is slow. Furthermore, when using a permanent magnet, the magnetic field is switched using a mechanical drive means, so a complicated mechanism is required. is necessary, and in this case too, the magnetic field switching speed will be slow.
以上述べた様に、従来のいずれの外部磁界印加手段によ
っても磁界切換え速度は遅いために、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
0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0また光磁気記録以外に
おいても種々の分野で大きな磁界を高速でスイッチング
できる装置が望まれている。As mentioned above, since the magnetic field switching speed is slow with any conventional external magnetic field application means, the above-mentioned batch erasing method is used for erasing, and for recording, the laser power is set at high speed while a constant magnetic field is applied. In other words, with conventional devices, it was impossible to provide so-called override performance in which new information is overwritten at high speed on already recorded information.In addition, there are various methods other than magneto-optical recording. In this field, there is a need for a device that can switch large magnetic fields at high speed.
(発明の目的)
本発明の目的は、この様な従来の欠点を除くために成さ
れたもので1り!1.大きい磁界の高速スイッチングが
可能な新規な外部磁界印加手段を提供することにある。(Object of the Invention) The object of the present invention is to eliminate such conventional drawbacks! 1. It is an object of the present invention to provide a novel means for applying an external magnetic field that is capable of high-speed switching of a large magnetic field.
(発明の構成)
本発明の磁界印加装置は永久磁石と、この永久磁石の少
なくとも一方の磁極に対向する部分及び巻線が施された
部分とを有する高透磁率磁性体から成るコア部とを備え
たことを特徴とする〇(構成の詳細な説明)
次に1本発明の構成について1図面を用いて詳細に説明
する0第1図は本発明に係る磁界印加手段の構成例を示
した図であシ、板状の永久磁石22と、この永久磁石の
一方の磁極に対向する部分と、巻線24を有した部分と
から成るL塑の高透磁率磁性体から成るコア部23とか
ら成る。そして巻@24は電流源に接続され1巻線24
への電流の有無によって、第2図(aL tb)に示す
様に、コア部下方への磁場の印加と遮蔽が選択される0
すなわち1巻M24に電流が流れていない時は、第2図
(、)に示す様にコア部23は、永久磁石22の磁極か
ら生じる磁束を、もう一方の磁極へ、効率良く導く磁路
を形成するため、コア部下方へは磁界が殆ど印加されな
い。一方、第2図(b)に示す様に、巻@24に電流I
が流れる場合、電流工によって。(Structure of the Invention) The magnetic field application device of the present invention includes a permanent magnet and a core portion made of a high magnetic permeability magnetic material having a portion facing at least one magnetic pole of the permanent magnet and a portion provided with a winding. (Detailed explanation of the configuration) Next, the configuration of the present invention will be explained in detail using one drawing.0 Figure 1 shows an example of the configuration of the magnetic field applying means according to the present invention. The figure shows a core part 23 made of a high permeability magnetic material made of L plastic, which is made up of a plate-shaped permanent magnet 22, a part facing one magnetic pole of the permanent magnet, and a part having a winding 24. Consists of. And winding @24 is connected to the current source and 1 winding @24
As shown in Figure 2 (aL tb), depending on the presence or absence of current to
That is, when no current flows through the first winding M24, the core section 23 creates a magnetic path that efficiently guides the magnetic flux generated from one magnetic pole of the permanent magnet 22 to the other magnetic pole, as shown in FIG. Because of this, almost no magnetic field is applied below the core. On the other hand, as shown in Fig. 2(b), a current I is applied to the winding @24.
If it flows, by the electrician.
コア部23内に生じる磁束の分だけ、永久磁石22の磁
極から磁束が外部に漏れるため、コア部下方の垂直方向
へバイアス磁界が印加される様になる。Since the magnetic flux generated in the core portion 23 leaks to the outside from the magnetic poles of the permanent magnet 22, a bias magnetic field is applied in the vertical direction below the core.
第2図(C)は巻線に流れる電流Iと、バイアス磁界H
IIとの関係を示したものである0バイアス磁界H8は
、電流Iの増加に伴って、増加し、コア部23内の磁化
が飽和に近づくにつれて、バイアス磁界H3も飽和する
傾向を示し、電流値工8以上では従来の永久磁石バイア
スと同等の大きいバイアス磁界を得ることができる。例
えば、この磁界印加手段1−、光磁気記録装置に適用す
るときには、第2図(aHb)に示した様に、記録媒体
1をコア部23の下方に配設する◇この時、記i媒体へ
の垂直方向の磁界印加は1巻線電流によって制御される
。Figure 2 (C) shows the current I flowing through the winding and the bias magnetic field H.
The zero bias magnetic field H8, which shows the relationship with II, increases as the current I increases, and as the magnetization in the core portion 23 approaches saturation, the bias magnetic field H3 also tends to be saturated, and the current When the value is 8 or more, a large bias magnetic field equivalent to that of a conventional permanent magnet bias can be obtained. For example, when this magnetic field applying means 1- is applied to a magneto-optical recording device, the recording medium 1 is disposed below the core portion 23 as shown in FIG. 2 (aHb). The vertical magnetic field application to is controlled by the single winding current.
ここで、永久磁石としては厚さ数ミリメートル。Here, a permanent magnet is several millimeters thick.
幅及び長さが数ミリ−数十ミリメートルのサマリウムコ
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、コア部23としては、厚さ数ミリメートル、磁
路長及び幅が数ミリ−数十ミリメートルのNiFe合金
もしくはNiZnフェライトやMnZn 7 xライト
等のソフトフェライトが用いられ、又、巻線24として
は、線径数十ミクロン〜数百ミクロンの鋼線が用いられ
、巻数は数十ターンである口又電流値工、としては、数
十〜数百ミリアンペアが適当である〇
この様にして構成した磁界印加手段では、巻線ノインダ
クタンスLを、1μH以下にすることが容易なため、数
百エルステッドオーダの磁界倉敷メガへルッオーダでの
高速切替が、コア部端面から数ミリメートル酸れた位置
において、容易に実現できる。A samarium cobalt magnet, alnico magnet, or ferrite magnet with a width and length of several millimeters to several tens of millimeters is used, and the core portion 23 is made of NiFe with a thickness of several millimeters and a magnetic path length and width of several millimeters to several tens of millimeters. An alloy or a soft ferrite such as NiZn ferrite or MnZn 7 The appropriate current value is several tens to hundreds of milliamperes. With the magnetic field applying means configured in this way, it is easy to reduce the winding noise inductance L to 1 μH or less, so it is on the order of several hundred oersteds. High-speed switching to the Kurashiki magnetic field can be easily achieved at a position several millimeters away from the end face of the core.
第3図〜第7図は外部磁界印加手段の他の構成例を示す
図である。FIGS. 3 to 7 are diagrams showing other configuration examples of the external magnetic field applying means.
第3図では、コア部27において、巻線28が施こされ
た部分の幅が永久磁石22の磁極に対向する部分より小
さいことt−特徴とする。In FIG. 3, the core portion 27 is characterized in that the width of the portion where the winding 28 is applied is smaller than the portion facing the magnetic pole of the permanent magnet 22.
第4図では、コア部29において1巻線30が施こされ
た部分の厚みが、永久磁石22の磁極に対向する部分よ
シ小さいことを特徴とする。In FIG. 4, the thickness of the portion of the core portion 29 where one winding 30 is applied is smaller than that of the portion facing the magnetic pole of the permanent magnet 22.
第5図ではコア部31において、巻@32が施こされた
部分の幅及び厚み共に、永久磁石22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 core portion 31 is characterized in that both the width and thickness of the portion where the winding @32 is applied are smaller than the portion facing the magnetic pole of the permanent magnet 22.
これらの構成例はいずれも第3図に示す第一の構成例に
比べて巻線部のコアの断面積金小さくすることによって
、よシ低い電流値で巻線部の磁化が飽和するようKでき
、その結果、印加磁界の高速切シ替えを容易にするもの
である。In each of these configuration examples, the cross-sectional area of the core of the winding portion is made smaller than that of the first configuration example shown in FIG. 3, so that the magnetization of the winding portion is saturated at a lower current value. This facilitates high-speed switching of the applied magnetic field.
第6図ではコア部37がU型金しておりこのため、永久
磁石22の磁極から発生する磁束を、第一の構成例より
効率良く、もう一方の磁極に導くことができるので、巻
[36に通電しない時におの内径と同じ位の穴42が設
けられたコア部40に、その穴位置と内径t−Sわせて
、取シ付けられている。光磁気記録に適用する場合、穴
42を光ビームの通路として使えるので、外部磁界印加
手段を記録媒体に対して、元ヘッドと同じ側に配設する
場合に適している〇
なお、永久磁石の磁極と高透磁率磁性体との間には接着
剤などが形成される場合がアシ、一定の間隔が存在して
もよい0また永久磁石の磁極と対向する位置の高透磁率
磁性体の部分は前記磁極端面と同じ形状かこれよシ大き
い形状であることが望ましいが、記録、消去に影響を及
ぼさない範囲で磁極端面の形状よシ小さくてもよい0電
流源20は電流の切換等の電流の制御機能を備えたもの
を使用することができ、あるいは電流制御手段を別に備
えてもよい0また高透磁率磁性体は永久磁石の両方の磁
極と対向する位置く形成してもよい。In FIG. 6, the core part 37 is formed into a U-shaped metal. Therefore, the magnetic flux generated from the magnetic pole of the permanent magnet 22 can be guided to the other magnetic pole more efficiently than in the first configuration example. The core part 40 is provided with a hole 42 of the same size as the inner diameter of the ax when the power is not applied to the axe 36, and the hole is aligned with the inner diameter t-S. When applied to magneto-optical recording, the hole 42 can be used as a path for the light beam, so it is suitable when the external magnetic field applying means is placed on the same side of the recording medium as the original head. An adhesive or the like may be formed between the magnetic pole and the high magnetic permeability magnetic material, and a certain distance may exist between the magnetic pole and the high magnetic permeability magnetic material. It is desirable that the current source 20 has the same shape as the magnetic pole end face or a larger shape, but it may be smaller than the shape of the magnetic pole end face as long as it does not affect recording or erasing. A magnet having a current control function may be used, or a current control means may be provided separately.Furthermore, the high magnetic permeability magnetic material may be formed at a position facing both magnetic poles of the permanent magnet.
(実施例)
第8図に示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
磁界印加手段としては、第5図に示したものを用いた口
これは永久磁石としては、厚さ2 mm幅及び高さ30
mmのアルニコ磁石を用い、コア部としては、 Mn
Znフェライトを、磁極に対向する部分が厚さ2 mr
r) flit 35 mmに1巻線部が厚さ1m高さ
10mmに、成形したものを用い。(Example) Using the magneto-optical recording/reproducing/erasing device shown in FIG. 8, information was recorded, reproduced, and erased on a magneto-optical disk. As the external magnetic field applying means, the one shown in FIG.
mm alnico magnet is used, and the core part is Mn
Zn ferrite with a thickness of 2 mr at the part facing the magnetic pole.
r) One winding part was molded into a flit of 35 mm with a thickness of 1 m and a height of 10 mm.
この両者を接着剤で接着したものから成る0巻線は、線
径100μmの巻線が50ターン巻かれたものから成る
。第8図ではこの様な、外部磁界印加手段4,5が記録
媒体の両側に永久磁石の磁極Nが互いに対向する様に配
設されている0なおこの図において外部磁界印加手段と
記録媒体面との示す角度は45°以上刃S望ましい0従
って、4のコイル通電中は、記録媒体に下向きのバイア
ス磁界が印加され、5のコイル通電中は上向きの磁界が
印加される◎ここで20は電流源である。光磁気記録用
ヘッド3は従来と同等のものであシ、次の様な構成を有
する。The zero winding, which is made by bonding these two together with an adhesive, is made by winding 50 turns of a wire with a wire diameter of 100 μm. In FIG. 8, such external magnetic field applying means 4 and 5 are arranged on both sides of the recording medium so that the magnetic poles N of the permanent magnets face each other. The angle indicated by the blade S is preferably 45° or more.0 Therefore, while the coil 4 is energized, a downward bias magnetic field is applied to the recording medium, and while the coil 5 is energized, an upward magnetic field is applied.◎Here, 20 is It is a current source. The magneto-optical recording head 3 is the same as the conventional one, and has the following configuration.
6は直線偏向のレーザ光源であシ、たとえば半導体レー
ザが使用される。7,8.9はビームスプリッタである
0レーザ光ビーム集光用レンズ10はアクチェエータI
IKよシ支持されている。フォーカスエラーならびにト
ラッテ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12、トラッキングエラー検出用受光素子1
3によりて検出されサーボ制御回路14.15に入力さ
れ、サーボ信号となシ、前記アクチェエータ11にフィ
ードバックされる。再生信号は偏光フィルタ16を通過
後、再生信号検出用受光素子17によって検出され、再
生信号増幅回路18によって増幅される。偏光フィルタ
16としては、たとえばグ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17としては、たとえ
ばPINフォトダイオードまたはアバ2ンシエフオト
ダイオードが使用される0レーザ光源6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。6 is a linearly polarized laser light source, for example, a semiconductor laser is used. 7, 8.9 are beam splitters 0 Laser beam focusing lens 10 is actuator I
It is supported by IK. The focus error and tracking error signals are received by a focus error detection light receiving element 12 and a tracking error detection light receiving element 1, respectively.
3 and input to the servo control circuits 14 and 15, and fed back to the actuator 11 as a servo signal. After passing through the polarizing filter 16, the reproduced signal is detected by the reproduced signal detection light receiving element 17, and is amplified by the reproduced signal amplification circuit 18. As the polarizing filter 16, for example, a Gram-Thompson prism is used. As the reproduction signal detection light receiving element 17, for example, a PIN photodiode or an aberration photodiode is used.
A laser light source modulation circuit is used to modulate the laser light source 6 using a diode, and the power of the laser light is modulated during recording, erasing, and reproduction.
光磁気ディスクとして120mmφのプラスチック基板
上にスパッタ法によ、tl TbFe膜ft800X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0.8 fim 、ピッチ2.5#m、深さ70
6Xの溝が形成されているいわゆるプリグループ基板を
用いた。As a magneto-optical disk, a disk was used in which a tl TbFe film having a thickness of 800× was formed on a 120 mmφ plastic substrate by sputtering. The board has a width of 0.8 fim, a pitch of 2.5 #m, and a depth of 70 m.
A so-called pre-group substrate in which 6X grooves were formed was used.
第9図(、)〜(d)に、記録の動作モード図を示す。FIGS. 9(a) to (d) show recording operation mode diagrams.
記録媒体をキエ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4,5
の巻線に、それぞれIA及び1.の変調電流を交互に流
すことによりて、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(4に示す様な記録磁化状態が実現
される◎まず、線速9(n/secにて、ディスク面上
4 mWの一定強度レーザ光を照射しながら、外部磁界
印加手段の巻線にIMHzで%200mAの変調電流を
流したところ、良好な記録ができた。この記録トラック
上に新たに同一条件で記録磁界t−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。前
に記録した信号の消え残シは見られなかった。External magnetic field application means 4 and 5 are applied while irradiating a laser beam of a certain intensity that can raise the recording medium to a Chieri temperature or higher.
windings IA and 1. respectively. An external magnetic field corresponding to the recording pattern is applied by alternating the modulation current of ◎ First, while irradiating the disk surface with a constant intensity laser beam of 4 mW at a linear velocity of 9 (n/sec), a modulated current of %200 mA at IMHz is applied to the winding of the external magnetic field applying means. As a result, good recording was achieved. When a new recording magnetic field of t-0, 5 MHz was applied to this recording track under the same conditions, recording corresponding to this recording magnetic field was completed. No residue was seen.
きるロ又、従来の方式における磁界印加手段としても用
いられることは言うまでもない。Needless to say, it can also be used as a magnetic field applying means in conventional systems.
(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。こ
の応用として、たとえば1光磁気記碌・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
可能なオーバライド性能が実現できる0(Effects of the Invention) As described above, according to the present invention, it is possible to provide an external magnetic field application device capable of high-speed switching of a large magnetic field. As an application of this, for example, the 1-optical magneto-optical recording/reproducing/erasing method can achieve override performance that allows direct desired recording without the need for conventional batch erasing.
第1図、第3図〜第7図は本発明の構成例を示す図、第
2図tab tb)、 (C)は本発明の詳細な説明す
る図、88図は本発明の実施例を示す図、第9図(a)
〜(dlは本発明の実施例の動作モード図である。
図において、1・・・光磁気ディスク、2・・・磁性薄
膜、3・・・光磁気記録用ヘッド、4,5,26゜33
.34,35,38・・・外部磁界印加手段、6・・・
レーザ光源、7,8.9・・・ビームスプリッタ。
10・・・レーザビーム集光用レンズ、11・・・アク
チニエータ、12.13・・・エラー検出用受光素子、
14.15・・・サーボ制御回路、16・・・偏光フィ
ルタ、17・・・再生信号検出用受光素子%18・・・
増幅回路、19・・・レーザ光源変調用回路、2o・・
パε流源、21・・・記録媒体走向方向、22.39・
・・永久磁石、2B、27,29,31,37,40・
・・高速@率磁性体からなるコア、24.28,30゜
32・・・巻線、42・・・穴、である。
¥1図
第2図
第2図
(C)
Ls I
鯛鴫 乙 図
第7図
n
第0図
第9図
言こす栗lo縁Aヒ4欠贅1FIGS. 1, 3 to 7 are diagrams showing configuration examples of the present invention, FIGS. Figure 9(a)
~(dl is an operation mode diagram of an embodiment of the present invention. In the figure, 1... magneto-optical disk, 2... magnetic thin film, 3... magneto-optical recording head, 4, 5, 26° 33
.. 34, 35, 38... External magnetic field applying means, 6...
Laser light source, 7, 8.9... Beam splitter. 10... Laser beam focusing lens, 11... Actiniator, 12.13... Light receiving element for error detection,
14.15... Servo control circuit, 16... Polarizing filter, 17... Light receiving element for detecting reproduced signal %18...
Amplification circuit, 19... Laser light source modulation circuit, 2o...
PA ε flow source, 21... Recording medium running direction, 22.39.
・Permanent magnet, 2B, 27, 29, 31, 37, 40・
...core made of high-speed magnetic material, 24.28, 30°32...winding, 42...hole. ¥1 Figure 2 Figure 2 (C) Ls I Taisho Otsu Figure 7 n Figure 0 Figure 9 Words Chestnut Lo Edge Ahi 4 Defect 1
Claims (1)
向する部分及び巻線が施された部分とを有する高透磁率
磁性体から成るコア部とを備えたことを特徴とする磁界
印加装置。1. A magnetic field applying device comprising a permanent magnet and a core portion made of a high magnetic permeability magnetic material and having a portion facing at least one magnetic pole of the permanent magnet and a portion provided with a winding.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2711285A JPH069082B2 (en) | 1985-02-14 | 1985-02-14 | Magnetic field application device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2711285A JPH069082B2 (en) | 1985-02-14 | 1985-02-14 | Magnetic field application device |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS61187101A true JPS61187101A (en) | 1986-08-20 |
JPH069082B2 JPH069082B2 (en) | 1994-02-02 |
Family
ID=12211985
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2711285A Expired - Lifetime JPH069082B2 (en) | 1985-02-14 | 1985-02-14 | Magnetic field application device |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH069082B2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4813007A (en) * | 1987-02-13 | 1989-03-14 | Oki Electric Industry Co., Ltd. | External magnetic field generating device |
US7535616B2 (en) | 2006-04-17 | 2009-05-19 | Fujitsu Limited | Polarization controlling apparatus and polarization operation apparatus |
-
1985
- 1985-02-14 JP JP2711285A patent/JPH069082B2/en not_active Expired - Lifetime
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4813007A (en) * | 1987-02-13 | 1989-03-14 | Oki Electric Industry Co., Ltd. | External magnetic field generating device |
US7535616B2 (en) | 2006-04-17 | 2009-05-19 | Fujitsu Limited | Polarization controlling apparatus and polarization operation apparatus |
Also Published As
Publication number | Publication date |
---|---|
JPH069082B2 (en) | 1994-02-02 |
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