JPH0221442A - Magneto-optical recorder - Google Patents

Magneto-optical recorder

Info

Publication number
JPH0221442A
JPH0221442A JP17136888A JP17136888A JPH0221442A JP H0221442 A JPH0221442 A JP H0221442A JP 17136888 A JP17136888 A JP 17136888A JP 17136888 A JP17136888 A JP 17136888A JP H0221442 A JPH0221442 A JP H0221442A
Authority
JP
Japan
Prior art keywords
disk
bias magnet
optical head
magneto
magnetic flux
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
JP17136888A
Other languages
Japanese (ja)
Inventor
Kohei Sunaga
耕平 須永
Kazuo Hasegawa
和男 長谷川
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.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric 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 Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP17136888A priority Critical patent/JPH0221442A/en
Publication of JPH0221442A publication Critical patent/JPH0221442A/en
Pending legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00Recording 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
    • G11B11/10Recording 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
    • G11B11/105Recording 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

Landscapes

  • Recording Or Reproducing By Magnetic Means (AREA)

Abstract

PURPOSE:To accurately record and erase information by varying the magnitude of a magnetic field generated from a bias magnet corresponding to the change of leakage flux in a direction intersecting orthogonally to a disk at the position of an optical head. CONSTITUTION:A control means 18 to vary the magnitude of a current permitted to flow on the bias magnet consisting of a electromagnet corresponding to the leakage flux in the direction intersecting orthogonally to the disk of a device is provided. In other words, the leakage flux in the direction intersecting orthogonally to the disk 1 at the position of the optical head is detected by a magnetic sensor 19 mounted on the optical head 13, and the magnitude of the current to be permitted to flow on the bias magnet 16 is varied by a control circuit 18 corresponding to the magnitude of the leakage flux. In such a way, it is possible to always set the optimum magnetic flux on a disk recording plane, and to record and erase the information accurately.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、光磁気ディスクの記録面に対して磁界を発
生させるバイアスマグネットを備えた磁気記録装置に関
するものである。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic recording device equipped with a bias magnet that generates a magnetic field against the recording surface of a magneto-optical disk.

〔従来の技術〕[Conventional technology]

第4図は従来の光磁気ディスク装置を示す斜視図であり
、第5図、第6図は第4図V−V線断面図である。図に
おいて、1は円盤状の光磁気ディスク(以下、ディスク
と称す)で、このディスク1は第7図に示したように、
その厚さ方向に磁気的な極性を持つように着磁され、そ
の極性は常温で安定するが、例えば200〜300℃の
高温になると不安定になり、外部から磁界が印加される
とその外部磁界と同一方向の極性に反転される性質を持
つ。また2はシャーシ、3はこのシャーシ2上に固定さ
れたスピンドルモータ、3aはこのスピンドルモータ3
の出力軸、4はこの出力軸3aに固定され、かつディス
ク1を搭載して回転駆動するターンテーブル、5a、5
bはシャーシ2上に適当距離を隔てて対向状態で固定さ
れたサポート、6はこのサポート5a、5bによって両
端が支持されたガイドロッド、7はシャーシ2上に固定
された軸受支持部材、8はこの軸受支持部材7に固着さ
れた軸受、9はシャーシ2上に固定されたモータ支持部
材、10はこのモータ支持部材9に固定された送りモー
タ、10aはこの送りモータの出力軸、11は一端がこ
の出力軸10aに同軸状に固着され、かつ他端が軸受8
によって支持されたリードスクリュー エ2はガイドロ
ッド8に摺動自在に押通されたスライド軸受部12aと
リードスクリュー11に螺合する雌ねじ部12bを有す
るキャリッジである。13は図示しないレーザダイオー
ドやレンズミラー等の光学部品およびトラッキングアク
チュエータやフォーカスアクチュエータを内蔵し、かつ
ディスク1の記録面上に情報の記録・消去・再生をする
光ヘッドで、この光ヘッド13はキャリッジ12によっ
てディスク1の半径方向に移動される。13aはこの光
ヘッド13から第5図に示したように一定の偏光方向を
もつレーザ光14を照射する対物レンズ、15はシャー
シ2に固定されたバイアスマグネット支持部材、16は
このバイアスマグネット支持部材15に固定支持され電
磁石によって構成された記録、消去兼用のバイアスマグ
ネットで、このバイアスマグネット16は対物レンズ1
3a移動範囲の全域にわたって、この対物レンズ13a
と対向するように配置されている。17は光ヘッドやス
ピンドルモータ3や送りモータ10等のバイアスマグネ
7)16を除いた磁性使用部材から生じているもれ磁束
の光ヘツド対物レンズ13a直上のディスクに垂直な方
向の合成もれ磁束である。
FIG. 4 is a perspective view showing a conventional magneto-optical disk device, and FIGS. 5 and 6 are sectional views taken along the line V--V in FIG. 4. In the figure, 1 is a disk-shaped magneto-optical disk (hereinafter referred to as a disk), and as shown in FIG.
It is magnetized so that it has magnetic polarity in the thickness direction, and the polarity is stable at room temperature, but becomes unstable at high temperatures of 200 to 300 degrees Celsius, and when a magnetic field is applied from the outside, the polarity is stable at room temperature. It has the property of being reversed in polarity in the same direction as the magnetic field. Further, 2 is a chassis, 3 is a spindle motor fixed on this chassis 2, and 3a is this spindle motor 3.
The output shaft 4 is fixed to the output shaft 3a, and a turntable 5a, 5 is fixed to the output shaft 3a and is rotatably driven by mounting the disk 1 thereon.
Reference numeral b denotes a support fixed on the chassis 2 facing each other at an appropriate distance, 6 a guide rod supported at both ends by the supports 5a and 5b, 7 a bearing support member fixed on the chassis 2, 8 a support A bearing fixed to this bearing support member 7, 9 a motor support member fixed on the chassis 2, 10 a feed motor fixed to this motor support member 9, 10a an output shaft of this feed motor, 11 one end is coaxially fixed to this output shaft 10a, and the other end is connected to a bearing 8.
The lead screw E 2 is a carriage having a slide bearing portion 12 a slidably pushed through the guide rod 8 and a female thread portion 12 b screwed into the lead screw 11 . Reference numeral 13 denotes an optical head that incorporates optical parts (not shown) such as a laser diode and lens mirror, as well as a tracking actuator and a focus actuator, and records, erases, and reproduces information on the recording surface of the disk 1. This optical head 13 is attached to a carriage. 12 in the radial direction of the disk 1. Reference numeral 13a denotes an objective lens for emitting laser light 14 having a fixed polarization direction as shown in FIG. 5 from this optical head 13, 15 denotes a bias magnet support member fixed to the chassis 2, and 16 denotes this bias magnet support member. A bias magnet for both recording and erasing is configured by an electromagnet and fixedly supported by the objective lens 1.
This objective lens 13a over the entire movement range of 3a.
is placed so as to face it. 17 is a composite leakage magnetic flux in the direction perpendicular to the disk directly above the optical head objective lens 13a, which is the leakage magnetic flux generated from the magnetic members other than the bias magnet 7) 16 such as the optical head, spindle motor 3, and feed motor 10. It is.

また第5図中の30はバイアスマグネット16から発生
している記録磁界、第6図中の31はバイアスマグネッ
ト16から発生している消去磁界である。
Further, 30 in FIG. 5 is a recording magnetic field generated from the bias magnet 16, and 31 in FIG. 6 is an erasing magnetic field generated from the bias magnet 16.

次に動作について説明する。Next, the operation will be explained.

ディスク1はターンテーブル4に載置され、スピンドル
モータ3が回転すると、それにともなって回転駆動され
る。このディスク1が所定の回転数に達するとディスク
1の記録面上に情報の記録。
The disk 1 is placed on a turntable 4, and when the spindle motor 3 rotates, the disk 1 is driven to rotate. When the disc 1 reaches a predetermined rotational speed, information is recorded on the recording surface of the disc 1.

消去、再生が可能となる。この状態で、送りモータ10
が回転し、それにともなってリードスクリュー11が回
転すると、このリードスクリューllに雌ねじ部12b
が螺合しているキャリッジ12が第4図の矢印A、B方
向に移動する。次に情報の記録、消去、再生について述
べる。第7図に示すように例えばディスク1は上向きに
初期着磁されている。情報を記録する際には、第5図に
示すようにバイアスマグネット16からはその真下で磁
力線の向きが下向きである記録磁界30を発生している
。このような状態で、光ヘッド13からレーザ光14を
ディスク1に照射すると、レーザ光14の当たった部分
が高温になり、この高温部分の極性が上向きから下向き
に反転する。この時レーザ光の光束8を断続することに
より第8図に示すように着磁方向の変化として情報が記
録できる。情報を消去する際には、第6図に示すように
バイアスマグネット16からその真下でディスク1の初
期着磁の方向と同方向の消去磁界31をかけなからレー
ザ光14をディスク1に連続的に照射するとレーザ光1
4の当たった部分はすべて初期着磁状態にもどり、情報
が消去される。情報を読出す場合はレーザ光14の出力
を記録、消去時よりも小さくし、ディスクが高温になら
ないようにしつつ、バイアスマグネット16からは磁界
を発生させない状態でレーザ光14を光ヘッド13より
ディスク1に照射する。照射されたレーザ光14はディ
スク1の記録面で反射して光ヘッド16にもどるが、こ
の反射光の偏光方向は出射した偏光方向からある角度だ
け回転している。これはカー効果として周知である。こ
の回転方向はレーザ光14の当たった部分の着磁状態(
第8図中のディスク1の矢印が上向きか下向きか)によ
って逆になるため、光へラド13内に設けられた一定の
偏光方向の光のみ通過させるフィルタ(図示せず)の後
側に受光素子(図示せず)を設けることにより、光のオ
ン/オフとしてディスク1上の情報を読出すことができ
る。
Erasing and reproducing are possible. In this state, the feed motor 10
rotates, and the lead screw 11 rotates accordingly, the female threaded portion 12b is attached to the lead screw ll.
The carriage 12 screwed together moves in the directions of arrows A and B in FIG. Next, we will discuss recording, erasing, and reproducing information. As shown in FIG. 7, for example, the disk 1 is initially magnetized upward. When recording information, as shown in FIG. 5, the bias magnet 16 generates a recording magnetic field 30 with magnetic lines of force pointing downward directly below it. When the laser beam 14 is irradiated onto the disk 1 from the optical head 13 in this state, the portion hit by the laser beam 14 becomes high temperature, and the polarity of this high temperature portion is reversed from upward to downward. At this time, by interrupting the beam 8 of the laser beam, information can be recorded as a change in the magnetization direction as shown in FIG. When erasing information, as shown in FIG. 6, an erasing magnetic field 31 is applied directly below the bias magnet 16 in the same direction as the initial magnetization direction of the disk 1, and the laser beam 14 is continuously applied to the disk 1. Laser light 1 when irradiated on
All the parts hit by 4 return to their initial magnetized state and the information is erased. When reading information, the output of the laser beam 14 is made lower than that during recording and erasing to prevent the disk from becoming hot, and the laser beam 14 is directed from the optical head 13 to the disk without generating a magnetic field from the bias magnet 16. Irradiate to 1. The irradiated laser beam 14 is reflected by the recording surface of the disk 1 and returns to the optical head 16, but the polarization direction of this reflected light is rotated by a certain angle from the emitted polarization direction. This is known as the Kerr effect. This direction of rotation is determined by the magnetized state (
Since the direction is reversed depending on whether the arrow of the disk 1 in FIG. By providing an element (not shown), information on the disk 1 can be read by turning on/off the light.

〔発明が解決しようとする課題〕[Problem to be solved by the invention]

従来の光磁気記録装置は上記のように構成されており、
光ヘッドやスピンドルモータや送りモータ等に使用され
る磁石から発生しているもれ磁束に対して考慮されてお
らず例えば第7図、第8図に示すように光ヘツド直上で
のバイアスマグネット以外の装置の合成もれ磁束17が
消去磁界31と同一方向であれば、ディスク1記録面上
の記録磁界30は弱められ、反対に消去磁界31は強め
られる。このようにして従来装置ではディスク記録面上
の最適な磁束密度から記録時、消去時ともに大きく外れ
、情報の正確な記録および消去ができなくなる可能性が
あるという問題点があった。
A conventional magneto-optical recording device is configured as described above.
No consideration is given to leakage magnetic flux generated from magnets used in optical heads, spindle motors, feed motors, etc. For example, as shown in Figures 7 and 8, bias magnets other than those directly above the optical head are not considered. If the composite leakage magnetic flux 17 of the device is in the same direction as the erase magnetic field 31, the recording magnetic field 30 on the recording surface of the disk 1 will be weakened, and on the contrary, the erase magnetic field 31 will be strengthened. In this manner, the conventional apparatus has a problem in that the magnetic flux density on the disk recording surface deviates significantly from the optimum magnetic flux density during both recording and erasing, and there is a possibility that accurate recording and erasing of information may not be possible.

この発明は上記のような問題点を解消するためになされ
たもので、装置のもれ磁束を考慮することによりディス
クの記録面上における磁束密度を最適磁束密度に近づけ
、情報の正確な記録および消去ができる光磁気記録装置
を得ることを目的とする。
This invention was made to solve the above-mentioned problems, and by taking the leakage magnetic flux of the device into consideration, the magnetic flux density on the recording surface of the disk approaches the optimum magnetic flux density, thereby achieving accurate information recording and The purpose of this invention is to obtain a magneto-optical recording device that can be erased.

〔課題を解決するための手段〕[Means to solve the problem]

この発明に係る光磁気記録装置は、電磁石からなるバイ
アスマグネットに流す電流の大きさを装置のディスクに
直交方向のもれ磁束に対応して可変する制御手段を備え
たものである。
A magneto-optical recording device according to the present invention is equipped with a control means for varying the magnitude of a current flowing through a bias magnet made of an electromagnet in accordance with leakage magnetic flux in a direction perpendicular to a disk of the device.

〔作用〕[Effect]

この発明においては、装置のディスクに直交方向のもれ
磁束に対応してバイアスマグネットに流す電流の大きさ
を可変する制御子゛段を備えた構成としたから、装置の
もれ磁束の影響を排除し、光磁気ディスク記録面上にお
いて常に最適な磁束密度にできる。
In this invention, since the disk of the device is equipped with a controller stage that varies the magnitude of the current flowing through the bias magnet in response to the leakage magnetic flux in the orthogonal direction, the influence of the leakage magnetic flux of the device can be reduced. Therefore, the optimal magnetic flux density can always be maintained on the magneto-optical disk recording surface.

〔実施例〕〔Example〕

以下、この発明の一実施例を図について説明する。 An embodiment of the present invention will be described below with reference to the drawings.

第1図は本発明の一実施例による光磁気記録装置を示す
斜視図である。同図において1〜17は従来装置と同様
であるため省略し、従来装置と異なる部分を説明する。
FIG. 1 is a perspective view showing a magneto-optical recording device according to an embodiment of the present invention. In the same figure, 1 to 17 are the same as those of the conventional device, so they will be omitted, and the parts that are different from the conventional device will be explained.

18は制御回路である。19は光ヘッド13上に取り付
けられた磁気センサで、その取付位置におけるディスク
1の垂直方向の磁界を測定する。
18 is a control circuit. A magnetic sensor 19 is mounted on the optical head 13 and measures the magnetic field in the vertical direction of the disk 1 at the mounting position.

次に動作について説明する。なお装置の基本的な動作は
従来装置と同様であるため省略し、従来と異なる動作に
ついて、重点的に説明する。装置のディスクモータ1等
の磁性使用部材からは従来と同様にもれ磁束が発生して
いるが、そのディスク1の記録面上のバイアスマグネッ
ト16をのぞいたディスクlに垂直な方向の光ヘツド1
3直上の合成もれ磁束17はたとえばディスク1内周に
近づくとディスクモータ4から生じているもれ磁束によ
って増加する等さまざまな要因によって、第2図に示す
ようにディスク1の半径方向の位置によって磁束の大き
さや向きが変化する。上記磁気センサ19を光へノド1
3上に取付けることにより、光ヘッド13の位置におけ
るディスク1に垂直な方向の磁束を測定するが、上記磁
気センサ19の取付は位置における垂直方向の磁束密度
(磁気センサの測定値)と光ヘツド直上のディスク記録
面の高さにおける垂直方向の磁束密度には相関関係があ
り、ディスク記録面上で最適な磁束密度にするには、磁
気センサ19の測定値がいくらであればよいかがわかっ
ているため、この値を基準値として、バイアスマグネッ
ト16の通電状態で第3図のブロック図に示すような上
記制御回路18で制御する。同図に示すように測定値が
基準値より小さい(磁束密度が最適値より小さい)場合
にはバイアスマグネット16に流す電流を増やすことに
よって最適値に近づけ、反対に測定値が基準値より大き
い場合にはバイアスマグネット16に流す電流を減らす
ことによってディスク1の記録面上で最適な磁束密度に
近づける。
Next, the operation will be explained. Note that the basic operation of the device is the same as that of the conventional device, so a description thereof will be omitted, and the explanation will focus on the operation that is different from the conventional device. Leakage magnetic flux is generated from magnetic components such as the disk motor 1 of the device as in the past, but the optical head 1 in the direction perpendicular to the disk 1 excluding the bias magnet 16 on the recording surface of the disk 1
The composite leakage magnetic flux 17 directly above the disk 1 increases due to leakage magnetic flux generated from the disk motor 4 as it approaches the inner circumference of the disk 1 due to various factors, and as shown in FIG. The magnitude and direction of the magnetic flux change. Node 1 to the above magnetic sensor 19 to light
3, the magnetic flux in the direction perpendicular to the disk 1 at the position of the optical head 13 is measured; There is a correlation between the magnetic flux density in the vertical direction at the height of the disk recording surface directly above, and it is known what value the magnetic sensor 19 should measure in order to achieve the optimum magnetic flux density on the disk recording surface. Therefore, using this value as a reference value, the bias magnet 16 is controlled by the control circuit 18 as shown in the block diagram of FIG. 3 while the bias magnet 16 is energized. As shown in the figure, if the measured value is smaller than the reference value (the magnetic flux density is smaller than the optimum value), increase the current flowing through the bias magnet 16 to bring it closer to the optimum value, and conversely, if the measured value is larger than the reference value In this case, by reducing the current flowing through the bias magnet 16, the magnetic flux density on the recording surface of the disk 1 can be approximated to the optimum value.

このように、本実施例では光ヘツド上に取り付けた磁気
センサで該光ヘツド位置のディスクに直交方向のもれ磁
束を検出し、制御回路でこのもれ磁束の大きさに対応し
てバイアスマグネットに流す電流の量を可変する構成と
したから、ディスク記録面上では常に最適な磁束密度に
することができ、情報の正確な記録、消去が可能となる
In this way, in this embodiment, the magnetic sensor attached to the optical head detects the leakage magnetic flux in the direction orthogonal to the disk at the optical head position, and the control circuit adjusts the bias magnet according to the magnitude of the leakage magnetic flux. Since the configuration is such that the amount of current flowing through the disc can be varied, the optimal magnetic flux density can always be maintained on the disk recording surface, making it possible to accurately record and erase information.

なお、上記実施例では光変調方式の例について述べたが
、磁界変調方式において使用できることは言うまでもな
い。
In the above embodiment, an example of the optical modulation method has been described, but it goes without saying that it can also be used in a magnetic field modulation method.

〔発明の効果〕〔Effect of the invention〕

以上のように、本発明によれば光磁気記録装置において
、光ヘツド位置のディスクに直交方向のもれ磁束の変化
に対応して、バイアスマグネットから発生する磁界の大
きさを変化させる構成としたから、ディスク記録面上で
は常に最適な磁束密度にすることができ、情報の正確な
記録、消去が可能となる効果がある。
As described above, in a magneto-optical recording device according to the present invention, the magnitude of the magnetic field generated from the bias magnet is changed in response to the change in leakage magnetic flux in the direction orthogonal to the disk at the optical head position. Therefore, the optimal magnetic flux density can be maintained on the disk recording surface at all times, and information can be accurately recorded and erased.

4 凹面の筒中fr説、明 第1図はこの発明の一実施例による光磁気記録装置を示
す斜視図、第2図は光ヘツド直上のディスク記録面高さ
におけるディスクに垂直な方向の合成もれ磁束のディス
ク半径方向位置による変化の一例を示す図、第3図は第
1図の実施例に用いる制御回路の一例を示すブロック図
、第4図は従来の光磁気記録装置のを示す斜視図、第5
図は記録時における第4図のV−V線断面図、第6は消
去時における第4図のV−V線断面図、第7図は光磁気
ディスクの初期の着磁状態を示す図、第8図は記録後の
光磁気ディスクの着磁状態の一例を示す図である。
Figure 1 is a perspective view showing a magneto-optical recording device according to an embodiment of the present invention, and Figure 2 is a composite view of the direction perpendicular to the disk at the height of the disk recording surface just above the optical head. 3 is a block diagram showing an example of a control circuit used in the embodiment of FIG. 1, and FIG. 4 is a perspective view showing a conventional magneto-optical recording device. Figure, 5th
6 is a sectional view taken along line V-V in FIG. 4 during recording, FIG. 7 is a sectional view taken along line V-V in FIG. 4 during erasing, and FIG. 7 is a diagram showing the initial magnetized state of the magneto-optical disk. FIG. 8 is a diagram showing an example of the magnetized state of the magneto-optical disk after recording.

1は光磁気ディスク、13は光ヘッド、16はバイアス
マグネット、17はもれ磁束、18は制御回路、19は
磁気センサ。
1 is a magneto-optical disk, 13 is an optical head, 16 is a bias magnet, 17 is a leakage magnetic flux, 18 is a control circuit, and 19 is a magnetic sensor.

なお図中同一符号は同−又は相当部分を示す。Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

【特許請求の範囲】[Claims] (1)光磁気ディスクに対して情報の記録等を行う光ヘ
ッドと前記光磁気ディスクの記録面に対して磁界を発生
させる電磁石からなるバイアスマグネットを備えた磁気
記録装置において、 前記バイアスマグネットに流す電流の大きさを装置のデ
ィスクに直交方向のもれ磁束に対応して可変する制御手
段を備えたことを特徴とする光磁気記録装置。
(1) In a magnetic recording device equipped with a bias magnet consisting of an optical head for recording information on a magneto-optical disk and an electromagnet for generating a magnetic field against the recording surface of the magneto-optical disk, a current is applied to the bias magnet. 1. A magneto-optical recording device comprising a control means for varying the magnitude of a current in response to leakage magnetic flux in a direction perpendicular to a disk of the device.
JP17136888A 1988-07-07 1988-07-07 Magneto-optical recorder Pending JPH0221442A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP17136888A JPH0221442A (en) 1988-07-07 1988-07-07 Magneto-optical recorder

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP17136888A JPH0221442A (en) 1988-07-07 1988-07-07 Magneto-optical recorder

Publications (1)

Publication Number Publication Date
JPH0221442A true JPH0221442A (en) 1990-01-24

Family

ID=15921884

Family Applications (1)

Application Number Title Priority Date Filing Date
JP17136888A Pending JPH0221442A (en) 1988-07-07 1988-07-07 Magneto-optical recorder

Country Status (1)

Country Link
JP (1) JPH0221442A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100387592B1 (en) * 1998-12-30 2003-10-17 주식회사 포스코 Regenerative burners that suppress the production of nitrogen oxides

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100387592B1 (en) * 1998-12-30 2003-10-17 주식회사 포스코 Regenerative burners that suppress the production of nitrogen oxides

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