JPH0770006B2 - Magnetoresistive head drive system - Google Patents
Magnetoresistive head drive systemInfo
- Publication number
- JPH0770006B2 JPH0770006B2 JP61278165A JP27816586A JPH0770006B2 JP H0770006 B2 JPH0770006 B2 JP H0770006B2 JP 61278165 A JP61278165 A JP 61278165A JP 27816586 A JP27816586 A JP 27816586A JP H0770006 B2 JPH0770006 B2 JP H0770006B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- thin film
- head
- magnetic
- magnetoresistive effect
- 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.)
- Expired - Lifetime
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
- Recording Or Reproducing By Magnetic Means (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は磁気抵抗効果ヘツドの駆動方式に係り、特に、
磁気記録媒体に書き込まれた磁気信号を読み出す磁気効
果ヘツドの駆動を制御するに好適な磁気抵抗効果ヘツド
の駆動方式に関する。The present invention relates to a drive system of a magnetoresistive head, and
The present invention relates to a magnetoresistive head driving method suitable for controlling driving of a magnetic effect head for reading a magnetic signal written in a magnetic recording medium.
磁気抵抗効果ヘツドは、磁気抵抗効果素子により形成さ
れた磁性薄膜の磁化の方向と、磁性薄膜に流す電流の方
向との相対角度に依存して抵抗が変化することを利用し
たヘツドであり、誘導型の薄膜ヘツドに代わるヘツドと
して実用化されている。誘導型磁気ヘツドは磁界の変化
を誘導コイルで検出するように構成されているので、磁
気テープのスピードが早くなるに従つて磁気ヘツドの出
力は高くなるが、磁気テープのスピードが遅くなると磁
気ヘツドの出力が低下し、磁気テープの速度によつては
磁気テープに書き込まれた情報を十分に読み出すことが
できない恐れがあつた。ところが磁気抵抗効果ヘッドの
場合には、磁界の強さを抵抗値の変化で検出するように
構成されているので、磁気テープのスピードが遅い場合
でも、磁気テープに書き込まれた情報を確実に読み出す
ことができる。The magnetoresistive head is a head that utilizes the fact that the resistance changes depending on the relative angle between the direction of the magnetization of the magnetic thin film formed by the magnetoresistive element and the direction of the current flowing through the magnetic thin film. It has been put to practical use as a head to replace the thin film head of the mold. Since the induction type magnetic head is configured to detect changes in the magnetic field with an induction coil, the output of the magnetic head increases as the speed of the magnetic tape increases, but when the speed of the magnetic tape decreases, the magnetic head decreases. However, there is a possibility that the information written on the magnetic tape cannot be read sufficiently depending on the speed of the magnetic tape. However, in the case of the magnetoresistive head, the strength of the magnetic field is detected by the change in the resistance value, so that the information written on the magnetic tape can be reliably read even when the speed of the magnetic tape is slow. be able to.
しかしながら、従来の磁気抵抗効果ヘツドは抵抗の変化
が被検出磁界に対して非線形性の特性であつたため、誘
導型磁気ヘツドの代わりに用いるには難があつた。そこ
で、米国特許第3493694号、米国特許第3814863号公報に
記載されているように、磁性薄膜にバイアス磁界を加え
て抵抗の非線形性を低減させることによつて実用化が図
られている。このバイアス方法としては、磁性薄膜の近
傍に永久磁石を配置し、永久磁石によつてバイアス磁界
を加える方法や、磁性薄膜の近傍に導体を配置し、導体
に電流を流すことによつて磁性薄膜にバイアス磁界を加
える方法や、磁性薄膜を複数個に分割し、かつ各磁性薄
膜を磁性媒体からの磁束の流れによつて約45°傾けて配
置し、各磁性薄膜に流れる電流からバイアス磁界を発生
させるバーバポール法等が提案されている。However, since the conventional magnetoresistive head has a non-linear characteristic with respect to the magnetic field to be detected, it is difficult to use it in place of the inductive magnetic head. Therefore, as described in U.S. Pat. No. 3493694 and U.S. Pat. No. 3,814,863, practical application has been achieved by applying a bias magnetic field to the magnetic thin film to reduce the nonlinearity of the resistance. This bias method includes a method of placing a permanent magnet near the magnetic thin film and applying a bias magnetic field with the permanent magnet, or a method of placing a conductor near the magnetic thin film and passing a current through the magnetic thin film. The method of applying a bias magnetic field to the magnetic thin film, or dividing the magnetic thin film into multiple parts, and arranging each magnetic thin film at an angle of about 45 ° due to the flow of the magnetic flux from the magnetic medium. The Barbapole method etc. to generate are proposed.
しかしながら、従来技術は、磁性薄膜に一定の電流を供
給する方式が採用されており、ジユール熱によつて磁性
薄膜の温度が上昇する点については配慮されておらず、
磁性薄膜の温度上昇によつて熱雑音が発生したり、磁性
薄膜が溶断したりする恐れがあった。However, the conventional technology adopts a method of supplying a constant current to the magnetic thin film, and does not consider the point that the temperature of the magnetic thin film rises due to the heat generated by the juule heat.
There is a possibility that thermal noise may occur or the magnetic thin film may melt due to the temperature rise of the magnetic thin film.
なお、特公昭59-46042号公報に記載されているように、
磁気抵抗素子に間欠的なパルス信号を供給する方式を採
用すれば、磁気抵抗素子による消費電力を小さくするこ
とはできる。しかし、磁気抵抗効果素子にバイアス磁界
を加えて抵抗の非線形性を低減させるようにしたヘッド
の場合には、磁気抵抗効果素子に間欠的なパルス信号を
供給したり、また、特開昭53-139512号公報、特開昭54-
21316号公報に記載されているように、磁気抵抗素子に
直流電圧を印加し、バイアス磁界発生用の導体に交流信
号を印加したりする方式を単に採用しても、磁気抵抗素
子がバイアス磁界発生用の導体から発生する熱の影響を
受け、磁気抵抗素子の特性が劣化する恐れがある。As described in Japanese Patent Publication No. 59-46042,
If a method of supplying an intermittent pulse signal to the magnetoresistive element is adopted, the power consumption by the magnetoresistive element can be reduced. However, in the case of a head in which a bias magnetic field is applied to the magnetoresistive effect element to reduce the non-linearity of the resistance, an intermittent pulse signal is supplied to the magnetoresistive effect element, 139512, JP-A-54-
As described in Japanese Patent No. 21316, even if the method of applying a DC voltage to the magnetoresistive element and applying an AC signal to the conductor for generating the bias magnetic field is simply adopted, the magnetoresistive element generates the bias magnetic field. There is a risk that the characteristics of the magnetoresistive element will be deteriorated due to the influence of heat generated from the conductor for use.
本発明の目的は、磁気抵抗効果素子とバイアス磁界発生
用導体の温度上昇をともに抑制することができる磁気抵
抗効果ヘッドの駆動方式を提供することにある。An object of the present invention is to provide a drive system for a magnetoresistive effect head capable of suppressing both the temperature rise of the magnetoresistive effect element and the bias magnetic field generating conductor.
前記目的は達成するために、本発明は、磁気抵抗効果素
子の近傍にバイアス磁界発生用導体を配置し、この導体
のバイアス磁界を受けた磁気抵抗効果素子により被検出
磁界を検出する磁気抵抗効果ヘッドにおいて、前記磁気
抵抗効果素子及び前記バイアス磁界発生用導体の両方
に、少なくとも無通電時間を含む間欠的な電気信号を供
給することを特徴とする磁気抵抗効果ヘッドの駆動方式
を採用したものである。In order to achieve the above object, the present invention provides a magnetoresistive effect in which a bias magnetic field generating conductor is arranged in the vicinity of a magnetoresistive effect element, and a magnetoresistive effect element that receives a bias magnetic field of this conductor detects a detected magnetic field. In the head, a drive system of a magnetoresistive effect head characterized by supplying an intermittent electric signal including at least a non-energized time to both the magnetoresistive effect element and the bias magnetic field generating conductor is adopted. is there.
前記した手段によれば、バイアス磁界を受けた磁気抵抗
効果素子が被検出磁界を検出するときに、磁気抵抗効果
素子とバイアス磁界発生用導体には、無通電時間を含む
間欠的な電気信号がそれぞれ供給されるので、バイアス
磁界発生用導体に無通電時間を有しない交流信号が供給
されたときよりも、磁気抵抗効果素子とバイアス磁界発
生用導体から発生するジュール熱を抑制することができ
る。According to the above-described means, when the magnetoresistive effect element that receives the bias magnetic field detects the detected magnetic field, the magnetoresistive effect element and the bias magnetic field generating conductor receive an intermittent electric signal including a non-energized time. Since each is supplied, Joule heat generated from the magnetoresistive effect element and the bias magnetic field generating conductor can be suppressed more than when an AC signal having no non-energization time is supplied to the bias magnetic field generating conductor.
以下、本発明の実施例を図面に基づいて詳細に説明す
る。Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
第１図には、本発明の好適な実施例の構成が示されてい
る。第１図において、磁気抵抗効果素子により形成され
た磁性薄膜10の両端には導電性の端子12,14が接続され
ている。端子12,14には、それぞれリード線16,18を介し
て端子20,22からの電気信号が供給されるようになつて
いる。リード線16の線路途中には抵抗24が挿入されてお
り、この抵抗24の両端に接続された端子26,28から磁気
抵抗効果ヘツドの出力電圧が発生するようになつてい
る。FIG. 1 shows the configuration of a preferred embodiment of the present invention. In FIG. 1, conductive terminals 12 and 14 are connected to both ends of a magnetic thin film 10 formed of a magnetoresistive effect element. Electrical signals from the terminals 20 and 22 are supplied to the terminals 12 and 14 via lead wires 16 and 18, respectively. A resistor 24 is inserted in the middle of the lead wire 16, and an output voltage of the magnetoresistive head is generated from terminals 26 and 28 connected to both ends of the resistor 24.
一方、磁性薄膜10にバイアス磁界を与えるために、磁性
薄膜10近傍に、バイアス磁界発生用導体30が配置されて
いる。この導体30には、この導体30の両端に接続された
端子32、34から、第２図に示すように、間欠的なバイア
ス電流が供給されるようになっている。On the other hand, in order to apply a bias magnetic field to the magnetic thin film 10, a bias magnetic field generating conductor 30 is arranged near the magnetic thin film 10. An intermittent bias current is supplied to the conductor 30 from terminals 32 and 34 connected to both ends of the conductor 30, as shown in FIG.
以上の構成において、導体30にバイアス電流が供給され
ると共に、端子20、22から、第３図（Ｂ）に示すよう
に、間欠的なパルス信号が入力されているときに、磁気
テープなどの磁性媒体から、第３図（Ｃ）に示すような
磁界が磁性薄膜10に作用すると、被検出磁界の影響によ
って磁性薄膜10の抵抗値が変化し、端子26、28からは、
第３図（Ａ）に示すようなパルス信号が出力される。In the above structure, when a bias current is supplied to the conductor 30 and an intermittent pulse signal is input from the terminals 20 and 22 as shown in FIG. When a magnetic field as shown in FIG. 3 (C) acts on the magnetic thin film 10 from the magnetic medium, the resistance value of the magnetic thin film 10 changes due to the effect of the magnetic field to be detected, and the terminals 26 and 28
A pulse signal as shown in FIG. 3 (A) is output.
ここで、端子20、22に印加されるパルス信号の周期を、
被検出磁界の変化の周期より十分に小さくすると、出力
端子26、28からは、振幅変調されたパルス信号が出力さ
れることになる。このため、出力信号の振幅を逐次検出
することによって、被検出磁界の強さを求めることがで
きる。Here, the period of the pulse signal applied to the terminals 20 and 22 is
When the period of change of the magnetic field to be detected is made sufficiently smaller, the amplitude-modulated pulse signal is output from the output terminals 26 and 28. Therefore, the strength of the magnetic field to be detected can be obtained by sequentially detecting the amplitude of the output signal.
このように、本実施例においては、磁性薄膜10と導体30
にそれぞれ無通電時間を含む間欠的な電気信号を供給す
るようにしたので、ジュール熱が時間平均の割合で低減
される。このため、導体30に無通電時間を有しない交流
信号を供給するときよりも、磁性薄膜10と導体30から発
生するジュール熱を抑制することができる。従って、磁
性薄膜10と導体30の温度上昇を共に低減することがで
き、熱雑音を低減できると共に磁性薄膜10の溶断を防止
できる。さらに、温度に応じた抵抗値の急激な変化を抑
制することができる。Thus, in this embodiment, the magnetic thin film 10 and the conductor 30 are
Since the intermittent electric signal including the non-energized time is supplied to each of them, the Joule heat is reduced at the time average rate. Therefore, Joule heat generated from the magnetic thin film 10 and the conductor 30 can be suppressed more than when supplying an AC signal having no non-energization time to the conductor 30. Therefore, the temperature rises of the magnetic thin film 10 and the conductor 30 can both be reduced, thermal noise can be reduced, and fusing of the magnetic thin film 10 can be prevented. Further, it is possible to suppress a rapid change in the resistance value depending on the temperature.
また、本実施例においては、端子20、22に交流のパルス
信号を印加するようにしているので、直流のパルス信号
を印加したときよりも、２倍の出力電圧を得ることがで
きる。Further, in this embodiment, since the AC pulse signal is applied to the terminals 20 and 22, it is possible to obtain an output voltage twice as high as that when the DC pulse signal is applied.
以上説明したように、本発明によれば、磁性薄膜とバイ
アス磁界発生用導体にそれぞれ無通電時間を含む間欠的
な電気信号を供給するようにしたので、導体に無通電時
間を有しない交流信号を供給するときよりも、磁性薄膜
と導体から発生するジュール熱を抑制することができ、
磁気抵抗効果ヘッドの長寿命化を図ることができると共
に信頼性の向上を図ることができる。As described above, according to the present invention, the magnetic thin film and the bias magnetic field generating conductor are each supplied with an intermittent electric signal including a non-energization time. Than when supplying, it is possible to suppress the Joule heat generated from the magnetic thin film and the conductor,
The life of the magnetoresistive head can be extended and the reliability can be improved.
第１図は本発明が適用された磁気抵抗効果ヘッドの構成
図、第２図はバイアス電流の波形図、第３図は磁気抵抗
効果ヘッドの作用を説明するための波形図である。 10……磁性薄膜、12,14,20,22,26,28,32,34……端子、2
4……抵抗、30……導体。FIG. 1 is a configuration diagram of a magnetoresistive effect head to which the present invention is applied, FIG. 2 is a waveform diagram of a bias current, and FIG. 3 is a waveform diagram for explaining the operation of the magnetoresistive effect head. 10 …… Magnetic thin film, 12,14,20,22,26,28,32,34 …… Terminal, 2
4 ... resistance, 30 ... conductor.
フロントページの続き (56)参考文献 特開 昭53−139512（ＪＰ，Ａ) 特開 昭54−21316（ＪＰ，Ａ) 特公 昭59−46042（ＪＰ，Ｂ２)Continuation of the front page (56) References JP-A-53-139512 (JP, A) JP-A-54-21316 (JP, A) JP-B-59-46042 (JP, B2)
Claims (2)
生用導体を配置し、この導体のバイアス磁界を受けた磁
気抵抗効果素子により被検出磁界を検出する磁気抵抗効
果ヘッドにおいて、前記磁気抵抗効果素子及び前記バイ
アス磁界発生用導体の両方に、少なくとも無通電時間を
含む間欠的な電気信号を供給することを特徴とする磁気
抵抗効果ヘッドの駆動方式。1. A magnetoresistive effect head in which a bias magnetic field generating conductor is arranged in the vicinity of a magnetoresistive effect element, and a magnetoresistive effect element that receives a bias magnetic field of the conductor detects a magnetic field to be detected. A driving method of a magnetoresistive head, characterized in that an intermittent electric signal including at least a non-conduction time is supplied to both the element and the bias magnetic field generating conductor.
ヘッドの駆動方式において、前記磁気抵抗効果素子に対
して、交流の間欠的な電気信号を供給することを特徴と
する磁気抵抗効果ヘッドの駆動方式。2. A magnetoresistive effect driving method according to claim 1, wherein an intermittent alternating electric signal is supplied to the magnetoresistive effect element. Head drive system.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61278165A JPH0770006B2 (en) | 1986-11-21 | 1986-11-21 | Magnetoresistive head drive system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61278165A JPH0770006B2 (en) | 1986-11-21 | 1986-11-21 | Magnetoresistive head drive system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63131303A JPS63131303A (en) | 1988-06-03 |
| JPH0770006B2 true JPH0770006B2 (en) | 1995-07-31 |
Family
ID=17593493
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61278165A Expired - Lifetime JPH0770006B2 (en) | 1986-11-21 | 1986-11-21 | Magnetoresistive head drive system |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0770006B2 (en) |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53139512A (en) * | 1977-05-11 | 1978-12-05 | Mitsubishi Electric Corp | Information detector |
| JPS6049970B2 (en) * | 1977-07-18 | 1985-11-06 | 三菱電機株式会社 | magnetic recording and reproducing device |
| JPS5946042A (en) * | 1982-09-09 | 1984-03-15 | Mitsubishi Electric Corp | Observing method for pin hole, crack and coverage of semiconductor device |
-
1986
- 1986-11-21 JP JP61278165A patent/JPH0770006B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63131303A (en) | 1988-06-03 |
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