JPH02121102A - Generated magnetic field control method - Google Patents
Generated magnetic field control methodInfo
- Publication number
- JPH02121102A JPH02121102A JP27093388A JP27093388A JPH02121102A JP H02121102 A JPH02121102 A JP H02121102A JP 27093388 A JP27093388 A JP 27093388A JP 27093388 A JP27093388 A JP 27093388A JP H02121102 A JPH02121102 A JP H02121102A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- coil
- generated
- basic
- recording
- 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
-
- 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、書替え可能な光ディスク等の、光学式記録再
生装置における、記録または消去時のバイアス磁界の制
御方式に係り、特に、記録または消去時のバイアス磁界
の発生を安定に行なうのに好適な発生磁界制御方式に関
する。Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a method for controlling a bias magnetic field during recording or erasing in an optical recording/reproducing device such as a rewritable optical disk, and particularly relates to a method for controlling a bias magnetic field during recording or erasing. The present invention relates to a generated magnetic field control method suitable for stably generating a bias magnetic field at a time.
［従来の技術］
この種の書替え型光学記録再生装置のバイアス磁界制御
方式として、従来、例えば特開昭５７−１３３５０３号
公報に記載の方式が知られている。[Prior Art] As a bias magnetic field control method for this type of rewritable optical recording/reproducing device, the method described in, for example, Japanese Patent Application Laid-Open No. 57-133503 is known.
この方式では、バイアス磁界を発生させるための電磁コ
イルと記録媒体の記録面との間の相対比ばが変化すると
き、フォーカスエラー信号を用いて上記電磁コイルの駆
動回路を制御することによつて、上記の相対距離が変化
しても、記録媒体にはいつも一定の磁界が加わるように
、発生磁界の強さを変化させる制御方式となっている。In this method, when the relative ratio between the electromagnetic coil for generating a bias magnetic field and the recording surface of the recording medium changes, a focus error signal is used to control the drive circuit of the electromagnetic coil. , the control system changes the strength of the generated magnetic field so that a constant magnetic field is always applied to the recording medium even if the above-mentioned relative distance changes.
なお、同様な制御を行なうものとして、特願昭６２−２
８２４６号の出願による提案もある。In addition, as a device that performs similar control, Japanese Patent Application No. 1986-2
There is also a proposal filed in application No. 8246.
［発明が解決しようとする課題］
上記従来技術は、バイアス発生用電磁コイルと記録媒体
との距離が変化しても記録媒体上での磁界強度を一定に
することは考慮されているけれども、周囲温度の変動や
電源電圧の変動によりバイアス発生用電磁コイルに流れ
る電流が変動し、発生磁界そのものが変動するという問
題については何も考慮されておらず、安定な記録および
消去を行なう上で問題があった。なお、上記の周囲温度
により発生磁界強度が変動するのは、コイル抵抗が温度
により変化するためと考えられる。[Problems to be Solved by the Invention] The above-mentioned conventional technology takes into consideration that the magnetic field strength on the recording medium is constant even if the distance between the bias-generating electromagnetic coil and the recording medium changes; No consideration was given to the problem that the current flowing through the electromagnetic coil for bias generation fluctuates due to temperature fluctuations or power supply voltage fluctuations, and the generated magnetic field itself fluctuates, which poses a problem in stable recording and erasing. there were. Note that the reason why the generated magnetic field strength varies depending on the ambient temperature is considered to be that the coil resistance changes depending on the temperature.
又、電磁コイルに流す電流値を、記録または消去に最低
限必要な大きさよりも可成り大きな値としておくことも
考えられるが、そのような大きな電流を流しておくこと
は、消費電力の点で望ましくない。Also, it is possible to set the current value flowing through the electromagnetic coil to a value considerably larger than the minimum value required for recording or erasing, but keeping such a large current flowing is disadvantageous in terms of power consumption. Undesirable.
従って１本発明の目的は、書替え型光学記録再生装置の
記録または消去バイアス磁界の発生を制御する方式にお
いて、電磁コイル（マグネットコイル）の発生磁界を安
定化させると共に、電磁コイルの消費電力を低減させる
発生磁界制御方式を提供することにある。Therefore, an object of the present invention is to stabilize the magnetic field generated by an electromagnetic coil (magnet coil) and reduce the power consumption of the electromagnetic coil in a method for controlling the generation of a recording or erasing bias magnetic field in a rewritable optical recording/reproducing device. The object of the present invention is to provide a generated magnetic field control method that allows the magnetic field to be generated.
［課題を解決するための手段］
上記目的を達成するため１本発明の書替え型光学式記録
再生装置における発生磁界制御方式は、バイアス磁界発
生用の基本コイルに加え、この基本コイルにより発生す
るバイアス磁界の所要値との差（不足分）を補うための
補償コイルと、この補償コイルの駆動回路と、基本コイ
ルに流れる電流の大きさを検出する検出手段と、前記補
償コイルの駆動回路と結合して、前記検出手段の検出結
果に基き前記補償コイルに流す電流の大きさを制御する
電流制御手段とを備え、この電流制御手段によって、基
本コイルと補償コイルとで綜合的に作る磁界の強度が常
に一定になるように制御が行なわれる構成とする。[Means for Solving the Problems] In order to achieve the above object, the generated magnetic field control method in the rewritable optical recording and reproducing device of the present invention includes, in addition to a basic coil for generating a bias magnetic field, a bias generated by this basic coil. A compensation coil for compensating for the difference (deficiency) between the required value of the magnetic field, a drive circuit for this compensation coil, a detection means for detecting the magnitude of the current flowing through the basic coil, and a combination with the drive circuit for the compensation coil. and current control means for controlling the magnitude of the current flowing through the compensation coil based on the detection result of the detection means, and the current control means controls the strength of the magnetic field comprehensively created by the basic coil and the compensation coil. The configuration is such that control is performed so that the value is always constant.
［作用コ 上記構成に基づく作用を説明する。[Action Co. The effect based on the above configuration will be explained.
記録または消去モードになったとき、基本コイルには、
設定電圧によってきめられた電流が流れる。基本コイル
による発生磁界強度は、該コイルに流れる電流の大きさ
により決定されるが、この電流値は、周囲温度の変化や
コイル自体の温度変化、あるいは電源電圧の変動によっ
て変動するため、発生磁界強度が変動する。この発生磁
界強度の変動は、前記検出手段によって、外乱を表わす
信号として検出される。この検出信号は補償コイル駆動
回路にフィードバックされ、補償コイルには前記発生磁
界強度の変動を補償する大きさの電流が流される。これ
により、基本コイルと補償コイルとを合せた綜合磁界強
度は、温度変化や電圧変化にかかわらず、常に一定の設
定強度に維持され、誤動作もなくなる。When in recording or erasing mode, the basic coil has
A current determined by the set voltage flows. The strength of the magnetic field generated by a basic coil is determined by the magnitude of the current flowing through the coil, but since this current value fluctuates due to changes in the ambient temperature, changes in the temperature of the coil itself, or fluctuations in the power supply voltage, the generated magnetic field The intensity fluctuates. This variation in the intensity of the generated magnetic field is detected by the detection means as a signal representing disturbance. This detection signal is fed back to the compensation coil drive circuit, and a current having a magnitude that compensates for the variation in the generated magnetic field strength is caused to flow through the compensation coil. As a result, the combined magnetic field strength of the basic coil and the compensation coil is always maintained at a constant set strength regardless of temperature changes or voltage changes, and malfunctions are eliminated.
例えば、比較的低い温度、比較的高い電源電圧のときに
、基本コイルのみで所定の（最低限必要な）磁界強度が
得られるように設計されているものとする。この場合１
周囲温度やコイル自体の温度が上昇すると（あるいは、
電源電圧が低下すると）基本コイルに流れる電流が低下
し、発生磁界強度に不足分が生じる。このとき、制御手
段により、補償コイルに、この不足分に相当する電流を
流し、不足分に相当する磁界を発生させる。この結果、
基本コイルと補償コイルとを合せた綜合磁界は所定の一
定磁界強度に維持される。For example, it is assumed that the design is such that a predetermined (minimum required) magnetic field strength can be obtained only with the basic coil when the temperature is relatively low and the power supply voltage is relatively high. In this case 1
When the ambient temperature or the temperature of the coil itself increases (or
When the power supply voltage decreases), the current flowing through the basic coil decreases, resulting in a deficiency in the generated magnetic field strength. At this time, the control means causes a current corresponding to this shortfall to flow through the compensation coil to generate a magnetic field corresponding to the shortfall. As a result,
The combined magnetic field of the basic coil and the compensation coil is maintained at a predetermined constant field strength.
ここで、消費電力についてみると、基本コイルに流す電
流値は、使用温度範囲の比較的低い値（電源電圧の比較
的高い方の値）のところで所定値となるように設定され
、温度上昇等で磁界に不足分が生じたとき、その不足分
を補う電流を補償コイルに流すだけでよいから、使用温
度範囲全域で基本コイルのみで所要磁界強度を得る方式
に比べて、本発明によれば、基本コイルおよび補償コイ
ルを合わせた消費電力を低減することができる。Regarding power consumption, the current value flowing through the basic coil is set so that it reaches a predetermined value at a relatively low value in the operating temperature range (a relatively high value of the power supply voltage). When a shortfall occurs in the magnetic field, it is only necessary to send current to the compensation coil to make up for the shortfall. Therefore, compared to a method that obtains the required magnetic field strength only with the basic coil over the entire operating temperature range, the present invention , the combined power consumption of the basic coil and the compensation coil can be reduced.
［実施例コ 以下、本発明の実施例を図面により説明する。[Example code] Embodiments 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が適用され、情報を記録、再
生、または消去する光デイスク記録再生装置のマグネッ
トコイル（バイアス磁界発生用電磁コイル）の制御系の
ブロック図である。第２図は、マグネットコイルの発生
磁界の変動を示す図である。FIG. 1 is a block diagram of a control system for a magnet coil (an electromagnetic coil for generating a bias magnetic field) of an optical disk recording/reproducing apparatus for recording, reproducing, or erasing information, to which an embodiment of the present invention is applied. FIG. 2 is a diagram showing fluctuations in the magnetic field generated by the magnet coil.
第１図において、１は光ディスク、２は記録面、３はス
ピンドルモータ、４は基本の（主の）電磁コイル（マグ
ネットコイル）、５は補償用（副の）電磁コイル、６は
光学系、７はコイル４の駆動回路（ドライブアンプ）、
８はコイル５の駆動回路（ドライブアンプ）、９は発生
磁界設定回路、１０は電流検出回路、１１は比較および
制御信号発生回路、１２は論理回路、１３はコイル４の
供給電流、１４はコイル５の供給電流、１５は制御信号
である。In Fig. 1, 1 is an optical disk, 2 is a recording surface, 3 is a spindle motor, 4 is a basic (main) electromagnetic coil (magnet coil), 5 is a compensation (sub) electromagnetic coil, 6 is an optical system, 7 is a drive circuit (drive amplifier) for coil 4;
8 is a drive circuit (drive amplifier) for the coil 5, 9 is a generated magnetic field setting circuit, 10 is a current detection circuit, 11 is a comparison and control signal generation circuit, 12 is a logic circuit, 13 is a supply current for the coil 4, 14 is a coil 5 is a supply current, and 15 is a control signal.
次に１本実施例の動作を説明する。Next, the operation of this embodiment will be explained.
書替え型記録媒体である光ディスク１は、情報の記録膜
面２を有し、スピンドルモータ３によって、定速または
可変速に回転するように制御される。通常のように、書
替え型光ディスク１への情報の記録、再生、または消去
を行なうため、光源と光学レンズを含む光学系６を出た
光束は、記録面２上に焦点を結ばされる。その光点にり
、記録面２に物理的変形または物性的変化を生じさせる
ことによって、情報の記録または消去を行なうようにす
る。例えば、光束を記録面に照射することにより、その
照射部分（光点）のみの温度を上昇させると同時に、外
部から磁界を印加することにより、温度上昇部分の磁化
の方向を外部印加磁界と同じ方向に向けることによって
、情報の記録または消去が行なわれる。また、この記録
面からの反射光または透過光を検出することによって、
記録情報の再生が行なわれる。An optical disc 1, which is a rewritable recording medium, has an information recording film surface 2, and is controlled by a spindle motor 3 to rotate at a constant speed or a variable speed. In order to record, reproduce, or erase information on the rewritable optical disc 1 as usual, a beam of light exiting an optical system 6 including a light source and an optical lens is focused on the recording surface 2. Information is recorded or erased by causing a physical deformation or physical change in the recording surface 2 using the light spot. For example, by irradiating a recording surface with a light beam, the temperature of only the irradiated area (light spot) is increased, and at the same time, by applying a magnetic field from outside, the direction of magnetization of the area where the temperature rises is the same as that of the externally applied magnetic field. By pointing in the direction, information is recorded or erased. In addition, by detecting reflected light or transmitted light from this recording surface,
The recorded information is reproduced.
このような情報の記録または消去方式において、外部磁
界の印加法として、マグネットコイルを用いる方法が用
いられる６情報の記録および消去時において、このマグ
ネットコイルから発生する磁界の安定性は、そのまま記
録・消去の安定性をもたらすことに繋がるため、発生磁
界の安定性を向上することは重要である。In such information recording or erasing methods, a method using a magnetic coil is used as a method of applying an external magnetic field.6 When recording and erasing information, the stability of the magnetic field generated from this magnetic coil remains unchanged during recording and erasing. Improving the stability of the generated magnetic field is important because it leads to stability in erasing.
情報の記録・消去命令は、論理回路１２により発行され
、該命令は発生磁界を決定するための設定回路９に送ら
れ、更に、ドライブアンプ７で所定値の電流１３に変換
されて、マグネットコイル４に供給される。これにより
、記録・消去のための磁界が発生される。Information recording/erasing commands are issued by the logic circuit 12, sent to the setting circuit 9 for determining the generated magnetic field, and further converted into a current 13 of a predetermined value by the drive amplifier 7, which is then sent to the magnet coil. 4. This generates a magnetic field for recording and erasing.
ところで、周囲温度やコイル４の温度が変動（上昇）す
ると、コイルの抵抗値も変動（上昇）し、このような抵
抗値の変動によって、また電源電圧の変動によって、マ
グネットコイル４に流れる電流が変動し、その結果、発
生磁界の変動が生じる。By the way, when the ambient temperature or the temperature of the coil 4 fluctuates (increases), the resistance value of the coil also fluctuates (increases), and due to such fluctuations in resistance value and fluctuations in the power supply voltage, the current flowing through the magnet coil 4 increases. fluctuations, resulting in fluctuations in the generated magnetic field.
そこで、本実施例では、発生磁界を決定する電流値を検
出回路１０で検出し、これを比較・制御信号発生回路１
１に印加すると共に、発生磁界設定回路９の出力を比較
・制御信号発生回路９の他方の入力として加える。この
比較・制御信号発生回路９の出力の制御信号１５はドラ
イブアンプ８に送られ、ここで、マグネットコイル４の
設定値からの変動分（不足分）を補償するように、マグ
ネットコイル５に流す電流値を決定する。このときのマ
グネットコイル４，５による発生磁界の模様を第２図に
示す。第２図で、横軸に矢示方向に温度Ｔの増加、また
は電源電圧Ｅの減少等の、マグネットコイルの発生磁界
を低減させる要因を示し、縦軸に発生磁界強度Ｈ（Ｍ封
鎖）を示す。第２図に示すように、外乱により変動する
マグネットコイル（基本コイル）４の発生磁界Ｈａは、
マグネットコイル（補償コイル）５の発生磁界Ｈｂによ
り補償されることになり、両コイルによる綜合磁界強度
Ｈａ＋Ｈｂは、常に、設定値の磁界強度と同じ値に維持
され、安定した磁界が得られるので、情報の記録、消去
の安定性を向上させることができる。Therefore, in this embodiment, the current value that determines the generated magnetic field is detected by the detection circuit 10, and this is detected by the comparison/control signal generation circuit 10.
1, and the output of the generated magnetic field setting circuit 9 is applied as the other input of the comparison/control signal generation circuit 9. The control signal 15 output from the comparison/control signal generation circuit 9 is sent to the drive amplifier 8, where it is sent to the magnet coil 5 so as to compensate for the variation (shortage) from the set value of the magnet coil 4. Determine the current value. The pattern of the magnetic field generated by the magnet coils 4 and 5 at this time is shown in FIG. In Figure 2, the horizontal axis shows factors that reduce the magnetic field generated by the magnet coil, such as an increase in temperature T or a decrease in power supply voltage E, in the direction of the arrow, and the vertical axis shows the generated magnetic field strength H (M blockade). show. As shown in Fig. 2, the magnetic field Ha generated by the magnet coil (basic coil) 4 that fluctuates due to disturbance is:
This will be compensated by the magnetic field Hb generated by the magnet coil (compensation coil) 5, and the combined magnetic field strength Ha+Hb from both coils will always be maintained at the same value as the set magnetic field strength, resulting in a stable magnetic field. The stability of recording and erasing information can be improved.
また、第２図の破ｇＨｏは、従来の１つのマグネットコ
イルのみで磁界を発生する場合であり、使用温度範囲で
設定値以下にならないようにすると、可成り大きな消費
電力となる。これに対し。Moreover, the failure gHo in FIG. 2 is the case where a magnetic field is generated by only one conventional magnet coil, and if the temperature is not lower than the set value within the operating temperature range, the power consumption will be considerably large. Against this.
本実施例では、基本コイル４の発生磁界Ｈａの最大値を
従来技術による発生磁界Ｈｏの最大値に比べて相当に低
くできるので、消費電力の低減および発熱の抑制をする
ことができる。In this embodiment, the maximum value of the magnetic field Ha generated by the basic coil 4 can be made considerably lower than the maximum value of the generated magnetic field Ho according to the prior art, so that power consumption can be reduced and heat generation can be suppressed.
第３図は、本発明の他の実施例による光デイスク記録再
生装置のマグネットコイル制御系のブロック図で、第１
図と同一構成部分には同一符号を付して説明を省略する
が、第１図と比べて２つの点で異なっている。FIG. 3 is a block diagram of a magnet coil control system of an optical disk recording/reproducing apparatus according to another embodiment of the present invention.
Components that are the same as those in the figures are given the same reference numerals and explanations are omitted, but there are two differences compared to FIG. 1.
その第１点は、マグネットコイル（基本コイル）４とマ
グネットコイル（補償コイル）５の間に、電気良導体板
からなるショートリング１６を挿入したことである。こ
れにより、磁界の立上り時におけるコイル４および５の
間の相互誘導を実効的に低減させる結果（立ち上りの磁
界変化で、リング１６に短絡電流が流れるため）、磁界
強度の低下を防止することができる。この場合、特に磁
界を反転させるときには、効果が大きい（反転に必要な
大きさの磁界を形成することができる。）。The first point is that a short ring 16 made of an electrically conductive plate is inserted between the magnet coil (basic coil) 4 and the magnet coil (compensation coil) 5. This effectively reduces the mutual induction between the coils 4 and 5 when the magnetic field rises (because a short-circuit current flows through the ring 16 due to the change in the magnetic field at the rise), and prevents a decrease in the magnetic field strength. can. In this case, the effect is particularly great when reversing the magnetic field (a magnetic field of a magnitude necessary for reversal can be formed).
その第２点は、磁界設定回路９よりも大きな設定値を持
つ第２の磁界設定回路１７を設け、記録モードまたは消
去モードのスタート時に、タイマ１８によりスイッチ１
９を磁界設定回路１７側に接続して、ある時間（Ｚｏｏ
μＳ〜数１００μｓ程度）だけ磁界設定回路１７により
発生磁界を制御するようにしたことである。これにより
、スタート時に強制的に磁界の立上り時間が短縮され、
記録モードや消去モードに切換ねる時間を短かくするこ
とができる。The second point is that a second magnetic field setting circuit 17 having a larger set value than the magnetic field setting circuit 9 is provided, and when the recording mode or erasing mode is started, the timer 18 causes the switch 1 to
9 to the magnetic field setting circuit 17 side for a certain period of time (Zoo
The generated magnetic field is controlled by the magnetic field setting circuit 17 by a period of about 10 μs to several 100 μs. This forces the rise time of the magnetic field to be shortened at the start,
The time required to switch to recording mode or erasing mode can be shortened.
なお、この発生磁界制御方式は、上記書替え型光学記録
再生装置のバイアス磁界制御のほかに、記録再生ヘッド
の粗アクチユエータのマグネットに適用して、安定にア
クセスができるようにすることもできる。In addition to controlling the bias magnetic field of the above-mentioned rewritable optical recording/reproducing device, this generated magnetic field control method can also be applied to the magnet of the coarse actuator of the recording/reproducing head to enable stable access.
［発明の効果］
以上詳しく述べたように、本発明の発生磁界制御方式に
よれば、書替え型光学記録再生装置の記録または消去磁
界を発生する場合に、基本電磁コイルおよび補償用電磁
コイルの２つのコイルを用い、補償用電磁コイルにより
、基本電磁コイルによる発生磁界強度の変動例えば低下
を補償するように制御するので１周囲温度の変動や電源
電圧の変動等の磁界変動を生じさせる外乱に対して、発
生磁界を安定化させて所定値に維持することができ、そ
れによって、書込みや消去を安定に誤りなく行なうこと
ができる等の効果を奏する。また。[Effects of the Invention] As described above in detail, according to the generated magnetic field control method of the present invention, when generating a recording or erasing magnetic field for a rewritable optical recording/reproducing device, two of the basic electromagnetic coil and the compensation electromagnetic coil are used. Using two coils, the compensation electromagnetic coil is controlled to compensate for fluctuations, such as decreases, in the magnetic field strength generated by the basic electromagnetic coil. As a result, the generated magnetic field can be stabilized and maintained at a predetermined value, resulting in effects such as being able to perform writing and erasing stably and without errors. Also.
発生磁界の設定は、従来のように最悪の条件を考慮して
行なう必要がないので、低くすることができ、それによ
って、電磁コイルによる消費電力を低減することができ
る効果を奏する。Since it is not necessary to set the generated magnetic field in consideration of the worst conditions as in the conventional case, the generated magnetic field can be set low, thereby achieving the effect that power consumption by the electromagnetic coil can be reduced.
第１図は本発明の一実施例を適用した光デイスク記録再
生装置のバイアス磁界発生用電磁コイルの制御系のブロ
ック図、第２図は電磁コイルの発生磁界の変動を示す図
、第３図は本発明の他の実施例を適用した電磁コイルの
制御系のブロック図である。
１・・・・・・光ディスク、２・・・・・・記録膜面、
３・・・・・・スピンドルモータ、４・・・・・・基本
（主）電磁コイル、５・・・・・・補償（副）電磁コイ
ル、６・・・・・・光学系、７゜８・・・・・・電磁コ
イル駆動アンプ、９，１７・・・・・・発生磁界設定回
路、１ｏ・・・・・・電流検出回路、１１・・・・・・
比較・制御信号発生回路、１２・・・・・・論理回路、
１６・・・・・・ショートリング、１８・・団・タイマ
。
％
図
＼
第２図
Ｔ ＥFig. 1 is a block diagram of a control system of an electromagnetic coil for generating a bias magnetic field in an optical disk recording/reproducing apparatus to which an embodiment of the present invention is applied, Fig. 2 is a diagram showing fluctuations in the magnetic field generated by the electromagnetic coil, and Fig. 3 FIG. 2 is a block diagram of a control system for an electromagnetic coil to which another embodiment of the present invention is applied. 1... Optical disc, 2... Recording film surface,
3...Spindle motor, 4...Basic (main) electromagnetic coil, 5...Compensation (sub) electromagnetic coil, 6...Optical system, 7° 8... Electromagnetic coil drive amplifier, 9, 17... Generated magnetic field setting circuit, 1o... Current detection circuit, 11...
comparison/control signal generation circuit, 12...logic circuit,
16...Short ring, 18...Dan/Timer. % Figure\Figure 2 T E
Claims (1)
コイルと、前記基本コイルの駆動回路とを有する書替え
型光学式記録再生装置における発生磁界制御方式におい
て、前記基本コイルにより発生するバイアス磁界の所要
値との差を補うための補償コイルと、前記補償コイルの
駆動回路と、前記基本コイルに流れる電流の大きさを検
出する検出手段と、前記補償コイルの駆動回路と結合し
ていて、前記検出手段の検出結果に基づき、前記基本コ
イルおよび補償コイルにより綜合的に発生する磁界の強
度が常に一定になるように前記補償コイルに流す電流の
大きさを制御する電流制御手段とを備えたことを特徴と
する発生磁界制御方式。 ２、前記基本コイルと前記補償コイルとの間に、ショー
トリングを備えたことを特徴とする請求項１記載の発生
磁界制御方式。 ３、記録または消去開始時に、前記基本コイルに流す電
流を一定時間だけ標準値よりも大きく設定するタイマ手
段を備えたことを特徴とする請求項１または２記載の発
生磁界制御方式。[Claims] 1. In a generated magnetic field control method in a rewritable optical recording/reproducing device having a basic coil that generates a bias magnetic field during recording or erasing, and a drive circuit for the basic coil, the magnetic field generated by the basic coil is A compensation coil for compensating for the difference between the bias magnetic field and a required value, a drive circuit for the compensation coil, a detection means for detecting the magnitude of the current flowing through the basic coil, and a drive circuit for the compensation coil. and current control means for controlling the magnitude of the current flowing through the compensation coil, based on the detection result of the detection means, so that the strength of the magnetic field comprehensively generated by the basic coil and the compensation coil is always constant. A generated magnetic field control method characterized by: 2. The generated magnetic field control method according to claim 1, further comprising a short ring between the basic coil and the compensation coil. 3. The generated magnetic field control method according to claim 1 or 2, further comprising timer means for setting the current flowing through the basic coil to be larger than a standard value for a certain period of time when recording or erasing is started.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27093388A JPH065563B2 (en) | 1988-10-28 | 1988-10-28 | Generated magnetic field control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27093388A JPH065563B2 (en) | 1988-10-28 | 1988-10-28 | Generated magnetic field control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02121102A true JPH02121102A (en) | 1990-05-09 |
| JPH065563B2 JPH065563B2 (en) | 1994-01-19 |
Family
ID=17493023
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27093388A Expired - Lifetime JPH065563B2 (en) | 1988-10-28 | 1988-10-28 | Generated magnetic field control method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH065563B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0817183A3 (en) * | 1995-04-07 | 1998-02-11 | Discovision Associates | Method and apparatus for controlling bias levels in a magneto-optical recording device |
| CN119480589A (en) * | 2025-01-15 | 2025-02-18 | 惠然科技有限公司 | Method and device for maintaining constant temperature of objective lens in charged particle beam system |
-
1988
- 1988-10-28 JP JP27093388A patent/JPH065563B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0817183A3 (en) * | 1995-04-07 | 1998-02-11 | Discovision Associates | Method and apparatus for controlling bias levels in a magneto-optical recording device |
| CN119480589A (en) * | 2025-01-15 | 2025-02-18 | 惠然科技有限公司 | Method and device for maintaining constant temperature of objective lens in charged particle beam system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH065563B2 (en) | 1994-01-19 |
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