JPS6394406A - Magnetic head driving circuit - Google Patents
Magnetic head driving circuitInfo
- Publication number
- JPS6394406A JPS6394406A JP23867986A JP23867986A JPS6394406A JP S6394406 A JPS6394406 A JP S6394406A JP 23867986 A JP23867986 A JP 23867986A JP 23867986 A JP23867986 A JP 23867986A JP S6394406 A JPS6394406 A JP S6394406A
- Authority
- JP
- Japan
- Prior art keywords
- coil
- magnetic head
- current
- switching element
- inductance
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 2
- 230000005669 field effect Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
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
Landscapes
- Recording Or Reproducing By Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
Ａ、産業上の利用分野
本発明は光磁気記録を行う磁気ヘッドを駆動するだめの
磁気ヘッド駆動回路に関する。DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a magnetic head drive circuit for driving a magnetic head that performs magneto-optical recording.
Ｂ０発明の概要
本発明は光磁気記録を行う磁気ヘッドを駆動するだめの
磁気ヘッド駆動回路において、少なくとも２つのスイッ
チング素子を交互にオン／オフさせ、磁気ヘッドのコイ
ルに流れる電流の向きを切換えるようにしたことにより
、該電流の立上り時間を充分に短かくすることができ、
また、省電力化を実現することができるようにしたもの
である。B0 Summary of the Invention The present invention is a magnetic head drive circuit for driving a magnetic head that performs magneto-optical recording. By doing so, the rise time of the current can be made sufficiently short,
Furthermore, it is possible to realize power saving.
Ｃ１従来の技術
従来より、情報の書換えが可能な光磁気ディスクが知ら
れている。この光磁気ディスクに情報を記録する方法と
して、例えば第５図に示すような、いわゆる重ね書き（
オーバーライド）が可能な磁場変調による方法が提案さ
れている。すなわち、光磁気ディスク１０１の垂直磁化
膜１０１ａに光学ピックアップ１０２による一定のレー
ザー光を照射し、垂直磁化膜１０１ａの温度をキュリ一
点以上に上げておき、磁気ヘッド１０３による磁場を記
録信号で変調して、垂直磁化膜１０１ａに該磁場の変化
のパターンに対応した磁気パターンを残すことにより、
情報の記録を行うものである。C1 Prior Art Magneto-optical disks on which information can be written are conventionally known. As a method of recording information on this magneto-optical disk, for example, the so-called overwriting (
A method using magnetic field modulation that allows for override has been proposed. That is, the perpendicularly magnetized film 101a of the magneto-optical disk 101 is irradiated with a constant laser beam from the optical pickup 102, the temperature of the perpendicularly magnetized film 101a is raised to one Curie point or above, and the magnetic field produced by the magnetic head 103 is modulated with a recording signal. By leaving a magnetic pattern corresponding to the pattern of change in the magnetic field on the perpendicularly magnetized film 101a,
It records information.
このような磁場変調方式により記録を行う場合には、例
えば、第６図（Ａ）に示すような矩形波状の記録信号に
対して、磁気ヘッド１０３のコイル１０３ａに流れる電
流は第６図（Ｂ）に示すようなある時定数を有する積分
波形となる。また、磁気ヘッド１０３による磁場は、第
６図（Ｃ）に示すように、上記電流波形と略等しい積分
波形となる。ここで、工ｄは駆動電流であり、出はこれ
に対応する磁場の強さである。When recording is performed using such a magnetic field modulation method, for example, the current flowing through the coil 103a of the magnetic head 103 is as shown in FIG. ) is an integral waveform with a certain time constant. Further, the magnetic field generated by the magnetic head 103 has an integral waveform substantially equal to the current waveform described above, as shown in FIG. 6(C). Here, d is the driving current, and d is the strength of the corresponding magnetic field.
Ｄ８発明が解決しようとする問題点
ところで、一般に、磁場変調方式による記録においては
、磁気ヘッドによる磁場を記録に必要な強さにし、また
磁場の立上り時間すなわち電流の立上り時間を充分に速
くする必要がある。−例として、磁場の強さＨｄを２０
００ｅ、立上り時間ｔを０．１μｓｅｃとし、駆動電流
ＩｄをＩＡ、また磁気ヘッドのコイルのインダクタンス
を５μＨとして、第７図に示すような駆動回路を用いる
場合を考える。いま、磁気ヘッドのコイル１０４のイン
ダクタンスをり、抵抗１０５の抵抗値をＲとすると、立
上り時間ｔは次式
により与えられる。但し、ここでは、立上り時間ｔを時
定数に等しいものとしている。D8 Problems to be Solved by the Invention In general, in recording using the magnetic field modulation method, it is necessary to make the magnetic field by the magnetic head as strong as necessary for recording, and to make the rise time of the magnetic field, that is, the rise time of the current, sufficiently fast. There is. - As an example, the magnetic field strength Hd is 20
00e, the rise time t is 0.1 μsec, the drive current Id is IA, and the inductance of the magnetic head coil is 5 μH, and a drive circuit as shown in FIG. 7 is used. Now, assuming that the inductance of the coil 104 of the magnetic head is R and the resistance value of the resistor 105 is R, the rise time t is given by the following equation. However, here, the rise time t is assumed to be equal to the time constant.
ここで、上式に前述した条件ｔ ＝ ０．１μｓｅｃ
。Here, the condition t = 0.1 μsec mentioned above in the above equation
.
Ｌ＝５μＨを代入して抵抗値Ｒを求めると、Ｒ−５０Ω
となる。よって電圧源１０６による駆動電圧ＶｄはＶｄ
＝１（Ａ）Ｘ５０（Ω）＝５０（Ｖ）となり、駆動電力
は５０Ｗにもなってしまう。Substituting L=5μH to find the resistance value R, we get R-50Ω.
becomes. Therefore, the driving voltage Vd by the voltage source 106 is Vd
= 1 (A) x 50 (Ω) = 50 (V), and the driving power becomes 50 W.
このように、立上り時間を充分短かくしようとすると、
駆動電力が非常に大きくなってしまうという問題点があ
った。In this way, if you try to shorten the rise time sufficiently,
There was a problem in that the driving power became extremely large.
そこで、本発明は上述した問題点に鑑みて提案されたも
のであり、磁気ヘッドのコイルに流れる電流の立上り時
間が充分に短かく、かつ駆動電力の小さな磁気ヘッド駆
動回路を提供することを目的とする。The present invention was proposed in view of the above-mentioned problems, and it is an object of the present invention to provide a magnetic head drive circuit in which the rise time of the current flowing through the coil of the magnetic head is sufficiently short and the drive power is low. shall be.
Ｅ０問題点を解決するだめの手段
本発明に係る磁気ヘッド駆動回路は、前述した問題点を
解決するために、光磁気記録を行う磁気ヘッドのコイル
に電流を供給するための直流電源と、記録信号に基づい
てオン／オフされる少なくとも２つのスイッチング素子
と、上記直流電源と上記磁気ヘッドのコイルとの間に設
けられ、上記磁気ヘッドのコイルのインダクタンスより
も充分大なるインダクタンスを有する補助コイルとを備
え、上記スイッチング素子を交互にオン／オフさせ、上
記磁気ヘッドのコイルに流れる電流の向きを切換えるよ
うにしたことを特徴としている。Means for Solving the E0 Problem In order to solve the above-mentioned problems, the magnetic head drive circuit according to the present invention includes a DC power supply for supplying current to the coil of a magnetic head that performs magneto-optical recording, and a recording at least two switching elements that are turned on and off based on signals; and an auxiliary coil that is provided between the DC power supply and the coil of the magnetic head and has an inductance that is sufficiently larger than the inductance of the coil of the magnetic head. The magnetic head is characterized in that the switching element is alternately turned on and off to switch the direction of the current flowing through the coil of the magnetic head.
Ｆ１作用
本発明によれば、スイッチング素子のスイッチング時間
程度のごく短時間で、磁気ヘッドのコイルに流れる電流
の向きが瞬間的に切換えられる。F1 action According to the present invention, the direction of the current flowing through the coil of the magnetic head can be instantaneously switched in a very short period of time equivalent to the switching time of the switching element.
Ｇ、実施例
以下、本発明の実施例について図面を参照しながら詳細
に説明する。G. EXAMPLES Hereinafter, examples of the present invention will be described in detail with reference to the drawings.
Ｇ−１，第１の実施例
第１図に第１の実施例の磁気ヘッド駆動回路を示す。こ
の第１図において、ヘッドコイル１は、磁場変調方式に
より光磁気記録を行うだめの磁気ヘッドのコイルであり
、インダクタンスＬｘを有している。上記ヘッドコイル
１の一端は補助コイル２を介して直流電源３に接続され
ていると共に、スイッチング素子Ｓ１１を介して接地さ
れている。また、上記ヘッドコイル１の他端は補助コイ
ル４を介して直流電源５に接続されていると共に、スイ
ッチング素子Ｓ１□を介して接地されている。上記補助
コイル２，４は、上記ヘッドコイル１のインダクタンス
Ｌｘよりも充分大なるインダクタンスＬｄをそれぞれ有
している（Ｌａ＞Ｌｘ）。また、上記直流電源３，５は
、記録に必要な電流（定電流）を上記ヘッドコイル１に
供給するためのものである。G-1, First Embodiment FIG. 1 shows a magnetic head drive circuit of a first embodiment. In FIG. 1, a head coil 1 is a coil of a magnetic head for performing magneto-optical recording using a magnetic field modulation method, and has an inductance Lx. One end of the head coil 1 is connected to a DC power source 3 via an auxiliary coil 2, and is also grounded via a switching element S11. The other end of the head coil 1 is connected to a DC power source 5 via an auxiliary coil 4, and is also grounded via a switching element S1□. The auxiliary coils 2 and 4 each have an inductance Ld that is sufficiently larger than the inductance Lx of the head coil 1 (La>Lx). Further, the DC power supplies 3 and 5 are for supplying the head coil 1 with a current (constant current) necessary for recording.
また、上記スイッチング素子Ｓｏ ＋ ８１２は、記録
信号に基づいてオン／オフされるようになっており、交
互にオン／オフされるよう釦なっている。すなわち、一
方がオンの時、他方はオフとなるように制御される。な
お、上記スイッチング素子Ｓ、１゜Ｓ１□には、実際に
は、トランジスタあるいはＦＥＴ（電界効果トランジス
タ）等が用いられる。Further, the switching element So + 812 is turned on/off based on the recording signal, and has a button so that it can be turned on/off alternately. That is, when one is on, the other is controlled to be off. Note that a transistor or a FET (field effect transistor) or the like is actually used for the switching element S, 1°S1□.
続いて、このように構成された磁気ヘッド駆動回路の動
作について説明する。なお、ヘッドコイル１に流れる電
流をＩｘとする。Next, the operation of the magnetic head drive circuit configured as described above will be explained. Note that the current flowing through the head coil 1 is assumed to be Ix.
いま、スイッチング素子Ｓｌｌがオンであり、スイッチ
ング素子Ｓ１□がオフの場合を考える。この時、補助コ
イル２には電源３による電流Ｉ、が流れ、補助コイル４
およびヘッドコイル１には電源５による電流工２が流れ
（ＩＸ＝Ｉ２）、よって、スイッチング素子Ｓｔｔには
これらの総和電流が流れる。ここで、Ｉ、＝Ｉ、とする
と、補助コイル４およびヘッドコイル１に蓄えられるエ
ネルギーは、それぞれとなる。Now, consider a case where switching element Sll is on and switching element S1□ is off. At this time, a current I from the power source 3 flows through the auxiliary coil 2, and the auxiliary coil 4
A current 2 from the power source 5 flows through the head coil 1 (IX=I2), and therefore, the sum of these currents flows through the switching element Stt. Here, if I,=I, the energy stored in the auxiliary coil 4 and the head coil 1 will be respectively.
次に、第２図に示すように、スイッチング素子Ｓｌｌが
オフとなり、スイッチング素子Ｓ１２がオンとなると、
この瞬間に補助コイル２とヘッドコイル１との接続点Ｐ
に高電圧（瞬間的には例えば数百Ｖ程度）が発生する。Next, as shown in FIG. 2, when the switching element Sll is turned off and the switching element S12 is turned on,
At this moment, the connection point P between the auxiliary coil 2 and the head coil 1
A high voltage (instantaneously, for example, about several hundred volts) is generated.
そして、その後、補助コイル２およびヘッドコイル１に
流れる電流は同一となる。この電流を工、とすると次式
に示す関係が成立する。After that, the current flowing through the auxiliary coil 2 and the head coil 1 becomes the same. If this current is expressed as , then the relationship shown in the following equation holds true.
この（１）式は、補助コイル２およびヘントコイル１に
それぞれ蓄えられるエネルギーの総和は、スイッチング
素子８１１ ＋ ｓ、ｔの切換の前後で等しくなるとい
うことを示している。上記（１）式を工、について解く
と、
となる。ここで、前述したように、Ｌ（１：＞Ｌｘであ
ることから、
工３ ”ｅ ＩＩ °−（３）
となり、ヘッドコイル１には向きが逆でほぼ同一の値の
電流を流すことができる。また、時間の概念はどこにも
なく、スイッチング素子Ｓ１□、Ｓｌ、のスイッチング
時間程度のごく短時間で、ヘッドコイル１に流れる電流
の向きを瞬間的に切換えることができる。この様子を第
３図のタイムチャートに示す。すなわち、例えば、第３
図（Ａ）に示すような矩形波状の記録信号に基づいて、
スイッチング素子Ｓｏ ＋ ８１２は第３図（Ｂ）およ
び第３図（Ｃ）に示すように交互にオン／オフされる。This equation (1) indicates that the total sum of energy stored in the auxiliary coil 2 and the hent coil 1 is equal before and after the switching elements 811 + s and t are switched. Solving the above equation (1) for engineering gives the following. Here, as mentioned above, since L(1:>Lx)
Therefore, currents of approximately the same value can be passed through the head coil 1 in opposite directions. Further, there is no concept of time, and the direction of the current flowing through the head coil 1 can be instantaneously switched in a very short time, such as the switching time of the switching elements S1□ and Sl. This situation is shown in the time chart of FIG. That is, for example, the third
Based on the rectangular waveform recording signal as shown in figure (A),
The switching element So + 812 is alternately turned on and off as shown in FIG. 3(B) and FIG. 3(C).
そして、この結果、ヘッドコイル１に流れる電流Ｉｘは
、第３図（Ｄ）に示すように、はとんど鈍りのない矩形
波状の波形となり、スイッチング素子Ｓｏ ＋ ＳＩ２
が切換わる度に電流Ｉｘの向きが瞬間的に切換えられる
ことになる。As a result, the current Ix flowing through the head coil 1 has a rectangular waveform with almost no dullness, as shown in FIG. 3(D), and the current Ix flows through the switching element So + SI2.
Each time the current Ix is switched, the direction of the current Ix is instantaneously switched.
また、この実施例の磁気ヘッド駆動回路には、素子とし
ての抵抗がなく、電源３，５は各コイル１．２．４の抵
抗弁に対して電流を流せば良いため、駆動電力は小さく
て済み、省電力化を実現することができる。In addition, the magnetic head drive circuit of this embodiment has no resistance as an element, and the power supplies 3 and 5 only need to send current to the resistance valves of each coil 1, 2, and 4, so the drive power is small. It is possible to realize power saving.
なお、現実には、記録信号の周波数をｆとすると、
で示されるエネルギーが、スイッチング素子Ｓ、１゜Ｓ
１２の切換えの度に損失される。そこで、例えばＬｘ＝
５μＨｔ Ｉｘ＝ＩＡ、 ｆ＝５００ＫＨｚとして（４
）式の値を算出すると、１．２５Ｗのエネルギー損失が
発生することになるが、このエネルギー損失を加味して
も、充分な省電力化が図られていることになる。In reality, if the frequency of the recording signal is f, then the energy shown by the switching element S, 1°S
It is lost every time 12 switches. So, for example, Lx=
5μHt Ix=IA, f=500KHz (4
) Calculating the value of the equation results in an energy loss of 1.25 W, but even when this energy loss is taken into consideration, sufficient power saving is achieved.
Ｇ−２，第２の実施例
第４図に第２の実施例の磁気ヘッド駆動回路を示す。こ
の第４図において、磁気ヘッドのコイルであるヘッドコ
イル６の一端はスイッチング素子Ｓ２１を介して、直流
電源７に接続された補助コイル８に接続されていると共
に、スイッチング素子Ｓ２□を介して接地されている。G-2, Second Embodiment FIG. 4 shows a magnetic head drive circuit of a second embodiment. In FIG. 4, one end of the head coil 6, which is the coil of the magnetic head, is connected to an auxiliary coil 8 connected to a DC power supply 7 via a switching element S21, and is also grounded via a switching element S2□. has been done.
また、上記ヘッドコイル６の他端はスイッチング素子８
２３を介して上記補助コイル８に接続されていると共に
、スイッチング素子Ｓ２．を介して接地されている。上
記補助コイル８は、ヘッドコイル６のインダクタンスＬ
ｘ’よりも充分大なるインダクタンスＬｄ’を有してい
る。また、スイッチング素子Ｓｔｔとスイッチング素子
Ｓ２１、およびスイッチング素子Ｓ２２とスイッチング
素子Ｓ２３は、それぞれ連動して切換えられる。また、
各スイッチング素子対は、記録信号に基づいて交互にオ
ン／オフされるようになっている。The other end of the head coil 6 is connected to a switching element 8.
23 to the auxiliary coil 8, and the switching element S2. is grounded through. The auxiliary coil 8 has an inductance L of the head coil 6.
It has an inductance Ld' that is sufficiently larger than x'. Further, the switching element Stt and the switching element S21, and the switching element S22 and the switching element S23 are respectively switched in conjunction with each other. Also,
Each pair of switching elements is alternately turned on and off based on a recording signal.
このように構成された第２の実施例の磁気ヘッド駆動回
路は、前述した第１の実施例のものと同様の動作原理に
基づいて駆動される。よって、動作の説明を省略する。The magnetic head drive circuit of the second embodiment thus configured is driven based on the same operating principle as that of the first embodiment described above. Therefore, the explanation of the operation will be omitted.
また、第１の実施例のものと同様の効果が得られること
は勿論である。Moreover, it goes without saying that the same effects as those of the first embodiment can be obtained.
Ｈ０発明の効果
上述した実施例の説明から明らかなように、本発明の磁
気ヘッド駆動回路によれば、少なくとも２つのスイッチ
ング素子を交互にオン／オフさせ、磁気ヘッドのコイル
に流れる電流の向きを切換えるようにしており、該電流
の立上り時間を充分に短かくすることができる。また、
素子としての抵抗を用いておらず、直流電源はコイルの
抵抗分に対して電流を流せば良いため、駆動電力は小さ
くて済み、省電力化を実現することができる。H0 Effects of the Invention As is clear from the description of the embodiments described above, the magnetic head drive circuit of the present invention alternately turns on and off at least two switching elements to control the direction of the current flowing through the coil of the magnetic head. The current rise time can be made sufficiently short. Also,
Since no resistance is used as an element, and the DC power supply only needs to flow a current corresponding to the resistance of the coil, the driving power is small, and power saving can be achieved.
第１図は本発明に係る磁気ヘッド駆動回路の第１の実施
例を示す回路図、第２図は上記第１の実施例の動作を説
明するだめの回路図、第３図は同じくタイムチャート、
第４図は本発明に係る磁気ヘッド駆動回路の第２の実施
例を示す回路図である。
第５図は磁場変調方式を説、明するための模式図、第６
図は従来例を説明するためのタイムチャート、第７図は
磁気ヘッド駆動回路の従来例を示す回路図である。
１．６・・・ヘッドコイル
２．４．８・・・補助コイル
３．５．７・・・直流電源
Ｓ＋＋ ＋ ＳＩ２＊ Ｓ２１ ＋ ５２２１５２３１
Ｓ２４ ・・・ス（ｙｆン”素子FIG. 1 is a circuit diagram showing a first embodiment of the magnetic head drive circuit according to the present invention, FIG. 2 is a circuit diagram for explaining the operation of the first embodiment, and FIG. 3 is a time chart. ,
FIG. 4 is a circuit diagram showing a second embodiment of the magnetic head drive circuit according to the present invention. Figure 5 is a schematic diagram for explaining the magnetic field modulation method, Figure 6
The figure is a time chart for explaining a conventional example, and FIG. 7 is a circuit diagram showing a conventional example of a magnetic head drive circuit. 1.6... Head coil 2.4.8... Auxiliary coil 3.5.7... DC power supply S++ + SI2* S21 + 52215231
S24...S(yfn" element)
Claims (1)
ための直流電源と、 記録信号に基づいてオン／オフされる少なくとも２つの
スイッチング素子と、 上記直流電源と上記磁気ヘッドのコイルとの間に設けら
れ、上記磁気ヘッドのコイルのインダクタンスよりも充
分大なるインダクタンスを有する補助コイルとを備え、 上記スイッチング素子を交互にオン／オフさせ、上記磁
気ヘッドのコイルに流れる電流の向きを切換えるように
したことを特徴とする磁気ヘッド駆動回路。[Claims] A DC power source for supplying current to a coil of a magnetic head that performs magneto-optical recording, at least two switching elements that are turned on/off based on recording signals, the DC power source and the magnetic head. and an auxiliary coil provided between the coil of the magnetic head and having an inductance sufficiently larger than the inductance of the coil of the magnetic head, the switching element is alternately turned on and off to control the current flowing through the coil of the magnetic head. A magnetic head drive circuit characterized by switching the direction.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23867986A JPH0743805B2 (en) | 1986-10-07 | 1986-10-07 | Magnetic head drive circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23867986A JPH0743805B2 (en) | 1986-10-07 | 1986-10-07 | Magnetic head drive circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6394406A true JPS6394406A (en) | 1988-04-25 |
| JPH0743805B2 JPH0743805B2 (en) | 1995-05-15 |
Family
ID=17033694
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23867986A Expired - Fee Related JPH0743805B2 (en) | 1986-10-07 | 1986-10-07 | Magnetic head drive circuit |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0743805B2 (en) |
Cited By (18)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0304298A2 (en) * | 1987-08-19 | 1989-02-22 | Sony Corporation | Magnetic head drive circuit |
| WO1992001285A1 (en) * | 1990-07-13 | 1992-01-23 | Deutsche Thomson-Brandt Gmbh | Circuit for reversing a magnetic field |
| EP0519729A2 (en) * | 1991-06-21 | 1992-12-23 | Sharp Kabushiki Kaisha | Magnetic head driving circuit |
| EP0540275A2 (en) * | 1991-10-31 | 1993-05-05 | Canon Kabushiki Kaisha | A circuit apparatus for driving a magnetic head |
| EP0545579A1 (en) * | 1991-11-18 | 1993-06-09 | Sharp Kabushiki Kaisha | External magnetic field generation apparatus and a magneto-optical recording apparatus |
| JPH0555302U (en) * | 1991-12-24 | 1993-07-23 | ティアック株式会社 | Digital recording circuit |
| EP0576286A2 (en) * | 1992-06-26 | 1993-12-29 | Canon Kabushiki Kaisha | Magnetic head driving device and magnetooptical recording apparatus |
| US5278809A (en) * | 1990-01-17 | 1994-01-11 | Olympus Optical Co., Ltd. | Photomagnetic recording apparatus recording with alternating magnetic field and D.C. magnetic field |
| US5329408A (en) * | 1991-07-10 | 1994-07-12 | Sharp Kabushiki Kaisha | Magnetic field modulation magnet-optical recording apparatus in which an FM modulator and a magnetic head driving circuit are used in common |
| US5351155A (en) * | 1991-12-24 | 1994-09-27 | Sharp Kabushiki Kaisha | Magnetic head driving device with pre-recording energization with two inductors sharing a common magnetic core |
| US5444688A (en) * | 1991-08-02 | 1995-08-22 | Sharp Kabushiki Kaisha | Information reproducing circuit |
| US5477509A (en) * | 1993-10-26 | 1995-12-19 | Tdk Corporation | Magneto-optical head circuit for minimizing the overshoot reversing current |
| US5559763A (en) * | 1992-03-06 | 1996-09-24 | Canon Kabushiki Kaisha | Magnetic head driving device and magnetooptical recording apparatus with acceleration coil for shortening current inversion time |
| US5574702A (en) * | 1993-08-06 | 1996-11-12 | Canon Kabushiki Kaisha | Magnetic head current control circuit for use in a magnetic head drive device, and magnetic/magnetooptical recording apparatus using the same |
| US5579293A (en) * | 1993-03-26 | 1996-11-26 | Canon Kabushiki Kaisha | Magnetic head driving circuit for controlling switching operations in a magnetooptical recording apparatus |
| US5587851A (en) * | 1991-12-24 | 1996-12-24 | Sharp Kabushiki Kaisha | Magnetic head driving device with prerecording energization |
| US6477119B2 (en) | 1999-12-16 | 2002-11-05 | Canon Kabushiki Kaisha | Magnetic head drive circuit including paired auxiliary coils, paired switching elements, and switch element control circuit, and magneto-optical recording device using the same |
| US6570725B1 (en) | 1999-07-12 | 2003-05-27 | Fujitsu Limited | Drive circuit for magnetic head and winding configuration of magnetic head suitable for the drive circuit |
-
1986
- 1986-10-07 JP JP23867986A patent/JPH0743805B2/en not_active Expired - Fee Related
Cited By (25)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0304298A2 (en) * | 1987-08-19 | 1989-02-22 | Sony Corporation | Magnetic head drive circuit |
| US5278809A (en) * | 1990-01-17 | 1994-01-11 | Olympus Optical Co., Ltd. | Photomagnetic recording apparatus recording with alternating magnetic field and D.C. magnetic field |
| WO1992001285A1 (en) * | 1990-07-13 | 1992-01-23 | Deutsche Thomson-Brandt Gmbh | Circuit for reversing a magnetic field |
| EP0519729A2 (en) * | 1991-06-21 | 1992-12-23 | Sharp Kabushiki Kaisha | Magnetic head driving circuit |
| US5359466A (en) * | 1991-06-21 | 1994-10-25 | Sharp Kabushiki Kaisha | Magnetic head driving circuit with impedance elements to balance auxiliary coil loads |
| US5329408A (en) * | 1991-07-10 | 1994-07-12 | Sharp Kabushiki Kaisha | Magnetic field modulation magnet-optical recording apparatus in which an FM modulator and a magnetic head driving circuit are used in common |
| US5444688A (en) * | 1991-08-02 | 1995-08-22 | Sharp Kabushiki Kaisha | Information reproducing circuit |
| EP0540275A2 (en) * | 1991-10-31 | 1993-05-05 | Canon Kabushiki Kaisha | A circuit apparatus for driving a magnetic head |
| US5377055A (en) * | 1991-10-31 | 1994-12-27 | Canon Kabushiki Kaisha | Circuit apparatus for driving a magnetic head |
| EP0545579A1 (en) * | 1991-11-18 | 1993-06-09 | Sharp Kabushiki Kaisha | External magnetic field generation apparatus and a magneto-optical recording apparatus |
| US5313444A (en) * | 1991-11-18 | 1994-05-17 | Sharp Kabushiki Kaisha | External magnetic field generation apparatus capable of light intensity modulation and magnetic field modulation |
| EP0855704A3 (en) * | 1991-12-24 | 2000-08-16 | Sharp Kabushiki Kaisha | A magnetic head driving device |
| US5351155A (en) * | 1991-12-24 | 1994-09-27 | Sharp Kabushiki Kaisha | Magnetic head driving device with pre-recording energization with two inductors sharing a common magnetic core |
| JPH0555302U (en) * | 1991-12-24 | 1993-07-23 | ティアック株式会社 | Digital recording circuit |
| US5587851A (en) * | 1991-12-24 | 1996-12-24 | Sharp Kabushiki Kaisha | Magnetic head driving device with prerecording energization |
| EP0855704A2 (en) * | 1991-12-24 | 1998-07-29 | SHARP Corporation | A magnetic head driving device |
| US5559763A (en) * | 1992-03-06 | 1996-09-24 | Canon Kabushiki Kaisha | Magnetic head driving device and magnetooptical recording apparatus with acceleration coil for shortening current inversion time |
| EP0576286A2 (en) * | 1992-06-26 | 1993-12-29 | Canon Kabushiki Kaisha | Magnetic head driving device and magnetooptical recording apparatus |
| US5661612A (en) * | 1992-06-26 | 1997-08-26 | Canon Kabushiki Kaisha | Magnetic head driving device and magnetooptical recording apparatus |
| EP0576286A3 (en) * | 1992-06-26 | 1994-08-10 | Canon Kk | Magnetic head driving device and magnetooptical recording apparatus |
| US5579293A (en) * | 1993-03-26 | 1996-11-26 | Canon Kabushiki Kaisha | Magnetic head driving circuit for controlling switching operations in a magnetooptical recording apparatus |
| US5574702A (en) * | 1993-08-06 | 1996-11-12 | Canon Kabushiki Kaisha | Magnetic head current control circuit for use in a magnetic head drive device, and magnetic/magnetooptical recording apparatus using the same |
| US5477509A (en) * | 1993-10-26 | 1995-12-19 | Tdk Corporation | Magneto-optical head circuit for minimizing the overshoot reversing current |
| US6570725B1 (en) | 1999-07-12 | 2003-05-27 | Fujitsu Limited | Drive circuit for magnetic head and winding configuration of magnetic head suitable for the drive circuit |
| US6477119B2 (en) | 1999-12-16 | 2002-11-05 | Canon Kabushiki Kaisha | Magnetic head drive circuit including paired auxiliary coils, paired switching elements, and switch element control circuit, and magneto-optical recording device using the same |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0743805B2 (en) | 1995-05-15 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |