JPS6154005A - Magneto-resistance effect type magnetic head device - Google Patents
Magneto-resistance effect type magnetic head deviceInfo
- Publication number
- JPS6154005A JPS6154005A JP17647684A JP17647684A JPS6154005A JP S6154005 A JPS6154005 A JP S6154005A JP 17647684 A JP17647684 A JP 17647684A JP 17647684 A JP17647684 A JP 17647684A JP S6154005 A JPS6154005 A JP S6154005A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- magnetic
- signal
- bias
- output
- 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
- 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
-
- 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
- G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
-
- 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
- G11B2005/0002—Special dispositions or recording techniques
- G11B2005/0005—Arrangements, methods or circuits
- G11B2005/001—Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
- G11B2005/0013—Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure of transducers, e.g. linearisation, equalisation
- G11B2005/0016—Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure of transducers, e.g. linearisation, equalisation of magnetoresistive transducers
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (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〕 本発明は磁気抵抗効果型磁気ヘッド装置に係わる。[Detailed description of the invention] [Industrial application field] The present invention relates to a magnetoresistive magnetic head device.
先ず、第４図を参照して、従来の磁気抵抗効果（以下Ｍ
Ｒという）型磁気ヘッド装置のヘッド部りの構造の一例
を説明するに、例えばＮｉ−Ｚｎ系フェライト・Ｍｎ−
Ｚｎ系フェライト等より成る磁性基板（１）上に（この
基板（１）が導電性を有する場合には、・これの上に被
着された５ｉ０２等の絶縁層（２）を介して）、後述す
るＭＲ感磁部（５）に対してバイアス磁界を与えるため
のバイアス磁界発生用の電流通路となる帯状の導電膜よ
り成るバイアス導体（３）が被着され、このバイアス導
体（３）上に、絶縁層（４）を介して例えば、Ｎｉ−Ｆ
ｅ系合金、或いは旧−ＣＯ系合金等のＭＲ磁性薄膜から
成るＭＲ感磁部（５）が配される。そして、このＭＲ感
磁部（５）上に、薄い絶縁層（６）を介して、各一端が
跨りバイアス導体（３）及びＭＲ感磁部（５）を横切る
方向に延在して夫々磁気回路の一部を構成する磁気コア
としての、例えばＭＯパーマロイから成る対の磁性層（
７）及び（８）が被着される。基板（１）上には、非磁
性の絶縁性保護Ｎ（９１を介して、保護基板（２）が接
合される。First, with reference to Fig. 4, the conventional magnetoresistive effect (hereinafter M
To explain an example of the structure of the head portion of a type magnetic head device (referred to as R), for example, Ni-Zn ferrite/Mn-
On a magnetic substrate (1) made of Zn-based ferrite or the like (if this substrate (1) has conductivity, via an insulating layer (2) such as 5i02 deposited thereon), A bias conductor (3) made of a strip-shaped conductive film that serves as a current path for generating a bias magnetic field to apply a bias magnetic field to an MR magnetic sensing part (5) to be described later is deposited on the bias conductor (3). For example, Ni-F is applied through the insulating layer (4).
An MR magnetic sensing part (5) made of an MR magnetic thin film of e-based alloy or old -CO-based alloy is arranged. Then, one end of each straddles the bias conductor (3) and the MR magnetically sensitive part (5) by extending in a direction across the bias conductor (3) and the MR magnetically sensitive part (5) via a thin insulating layer (6). A pair of magnetic layers (for example, made of MO permalloy) as a magnetic core forming part of a circuit
7) and (8) are applied. A protection substrate (2) is bonded onto the substrate (1) via a non-magnetic insulating protection N (91).
しかして、一方の磁性Ｎ（７）と基板（１）の前方端と
の間には、例えば絶縁層（６）より成る所要の厚さを有
する非磁性ギャップスペーサＪｉｉｉ（１１）が介在さ
れて、前方の磁気ギャップｇが形成される。そして、こ
の磁気ギャップｇが臨むように、基板（１）、ギャップ
スペーサＮ（１１） 、磁性Ｎｊ （７１、保護層（９
）及び保護基板Ｑａｌの前方面が＠磨されて磁気テープ
の如き磁気記録媒体との対接面（１２）が形成される。Therefore, a non-magnetic gap spacer Jiii (11) made of, for example, an insulating layer (6) and having a required thickness is interposed between one magnetic N (7) and the front end of the substrate (1). , a front magnetic gap g is formed. Then, the substrate (1), the gap spacer N (11), the magnetic Nj (71), the protective layer (9
) and the front surface of the protective substrate Qal are polished to form a surface (12) that faces a magnetic recording medium such as a magnetic tape.
又、磁気ギャップｇを構成する磁性層（７）の後方端と
、他方の磁性層（８）の前方端とは、夫々ＭＲ感磁部（
５）上に絶縁Ｍ（６）を介して跨るように形成されるも
、両端間には互いに離間する不連続部（１３）が形成さ
れる。両磁性層（７）及び（８）の夫々後方端及び前方
端は、絶縁層（６）の介在によって電気的には絶縁され
るも、不連続部（１３）において磁気的には結合される
ようなされる。かくして、基板（１）−磁気ギャップビ
ー磁性層（７） −Ｍ Ｒ怒磁部（５）−磁性層（８）
一基板（１）の閉磁路から成る磁気回路が形成される。Further, the rear end of the magnetic layer (7) constituting the magnetic gap g and the front end of the other magnetic layer (8) are connected to the MR magnetic sensing portion (
5) A discontinuous portion (13) is formed so as to straddle the top via an insulator M (6), but is spaced apart from both ends. The rear and front ends of both magnetic layers (7) and (8) are electrically insulated by the interposition of the insulating layer (6), but are magnetically coupled at the discontinuous portion (13). It is done like this. Thus, substrate (1) - magnetic gap magnetic layer (7) - M R angry magnetic part (5) - magnetic layer (8)
A magnetic circuit consisting of a closed magnetic path of one substrate (1) is formed.
このようなＭＲ型磁気ヘッド部りにおいては、その磁気
記録媒体と対接する前方ギャップｇからの信号磁束が上
述の磁気回路を流れることによって、この磁気回路中の
ＭＲ感磁部（５）の抵抗値が、この信号磁束による外部
磁界に応じて変化する。In such an MR type magnetic head section, the signal magnetic flux from the front gap g that is in contact with the magnetic recording medium flows through the above-mentioned magnetic circuit, thereby increasing the resistance of the MR magnetic sensing section (5) in this magnetic circuit. The value changes depending on the external magnetic field due to this signal magnetic flux.
そこで、ＭＲ感磁部（５）に検出電流を流し、この抵抗
値変化をこのＭＲ感磁部（５）の両端の電圧変化として
検出して、磁気媒体上の記録信号の再生を行う。Therefore, a detection current is passed through the MR magnetic sensing section (5), and this change in resistance value is detected as a voltage change across the MR magnetic sensing section (5), thereby reproducing the recorded signal on the magnetic medium.
この場合、ＭＲ感磁部（５）が磁気センサーとして線形
に動作し、且つ高感度とするためには、このＭＲ感磁部
（５）を磁気的にバイアスする必要がある。In this case, in order for the MR magnetic sensing section (5) to operate linearly as a magnetic sensor and to have high sensitivity, it is necessary to magnetically bias the MR magnetic sensing section (5).
このバイアス磁界は、バイアス導体（３）への通電によ
って発生する磁界と、ＭＲ感磁部（５）に通ずる検出電
流によってそれ自体が発生する磁界とによって与えられ
る直流磁界である。This bias magnetic field is a DC magnetic field given by a magnetic field generated by energizing the bias conductor (3) and a magnetic field itself generated by the detection current flowing to the MR magnetic sensing section (5).
即ち、この種のＭＲ型磁気ヘッド装置は、第５図にその
概略的構成をボすように、ＭＲ感磁部（５）に、バイア
ス導体（３）への直流電流ｉＢの通電によって発生した
磁界と、ＭＲ惑磁部（５）への検出電流ｉ １１Ｒの通
電によって発生した磁界とによってバイアス磁界ＨＢが
与えられた状態で、前述した磁気媒体からの信号磁界Ｈ
Ｅが与えられる。゛そして、この信号磁界Ｈ５による抵
抗変化に基づ＜ＭＲ感磁部（５）の両端電圧、すなわち
Ａ点の電位の変化を、低域阻止用コンデンサ（１６）を
介して増幅器（１４）に供給して増幅して出力端子（１
５）より出力するものである。That is, in this type of MR type magnetic head device, as shown in the schematic structure of FIG. In a state where a bias magnetic field HB is applied by the magnetic field and the magnetic field generated by energizing the detection current i11R to the MR magnetism section (5), the signal magnetic field H from the magnetic medium described above is applied.
E is given.゛Then, based on the resistance change caused by this signal magnetic field H5, the voltage across the MR magnetic sensing section (5), that is, the change in the potential at point A, is transmitted to the amplifier (14) via the low-frequency blocking capacitor (16). Supply and amplify the output terminal (1
5).
第６図は、このＭＲ感磁部（５）に与える磁界Ｈと、そ
の抵抗値Ｒとの関係を示す動作特性曲線図を示し、この
曲線は、磁界Ｈの絶対値が小さい範囲ＨＢＲ〜＋ＨＢＲ
において上に凸の２次曲線を示すが、磁界Ｈの絶対値が
大となって、この範囲から外れると、ＭＲ感磁部（５）
を構成するＭＲ磁性薄膜の中央部分の磁化が磁気回路方
向に飽和しはじめ、２次曲線から離れてその抵抗Ｒは最
小値Ｒｍｉｎに漸近する。因みに、この抵抗Ｒの最大値
Ｒｍａｘは、ＭＲ磁性薄膜の磁化がすべて電流方向に向
いた状態に於ける値である。そして、この動作特性曲線
における２次曲線の特性部分で、前述したバイアス磁界
Ｈａが与えられた状態で、第６し１において符号（１７
）を付して示す磁気媒体からの信号磁界が与えられるよ
うにして、これに応じて同図中符号（１８）で示す抵抗
値変化に基づく出力を得るようにしている。この場合は
、信号磁界の大きさが大となるほど２次Ａ１１ｄ波歪が
大となることが分る。FIG. 6 shows an operating characteristic curve diagram showing the relationship between the magnetic field H applied to this MR magnetic sensing part (5) and its resistance value R.
shows an upwardly convex quadratic curve, but when the absolute value of the magnetic field H becomes large and deviates from this range, the MR magnetic sensing part (5)
The magnetization of the central portion of the MR magnetic thin film constituting the MR magnetic thin film begins to saturate in the direction of the magnetic circuit, and the resistance R departs from the quadratic curve and approaches the minimum value Rmin. Incidentally, the maximum value Rmax of this resistance R is a value in a state where all the magnetization of the MR magnetic thin film is oriented in the current direction. Then, in the characteristic part of the quadratic curve in this operating characteristic curve, in the state where the bias magnetic field Ha mentioned above is applied, the sign (17
) is applied from the magnetic medium, and in response to this, an output based on a change in resistance value, indicated by reference numeral (18) in the figure, is obtained. In this case, it can be seen that as the magnitude of the signal magnetic field increases, the secondary A11d wave distortion increases.
又、上述のＭＲ型磁気ヘッド装置における第５図のＡ点
の電位は、ＭＲ感磁部（５）の抵抗の固定骨と変化分と
の合成によって決まる電位となるが、この場合、その固
定骨は９８％程度にも及ぶものであり、この抵抗の固定
骨の温度依存性が大きいので、Ａ点における電位の温度
ドリフトが大きいという欠点がある。このＭＲ感磁部（
５）の抵抗値Ｒは、Ｒ＝Ｒｏ （１＋αｃｏｓ’ θ
）・・・・（１）（但し、Ｒｏは抵抗の固定骨、αは最
大１１（抗変化率、θはＭＲ感磁部（５）における電流
方向と磁化方向とのなす角度である）で表され、例えば
ＭＲ感磁部（５）が８１Ｎｉ １９Ｆｅ （パーマロ
イ）合金による厚さ２５０人のＭＲ磁性ｉ７膜から成る
場合のαの実測値はα＝ ０．０１７程度である。この
αの値は、ＭＲ感磁部（５）のＭＲ磁性Ｖｉ、膜の膜厚
や材料によって多少の相違はあるものの嵩々α＝０．０
５程度である。Furthermore, the potential at point A in FIG. 5 in the above-mentioned MR type magnetic head device is a potential determined by the combination of the fixed bone and the variation of the resistance of the MR magnetic sensing part (5). The resistance of the fixed bone is approximately 98%, and the temperature dependence of the fixed bone is large, so there is a drawback that the temperature drift of the electric potential at point A is large. This MR magnetic sensing part (
5) resistance value R is R=Ro (1+αcos' θ
)...(1) (However, Ro is the fixed bone of the resistance, α is the maximum 11 (resistance change rate, θ is the angle between the current direction and the magnetization direction in the MR magnetic sensing part (5)) For example, when the MR magnetic sensing part (5) is made of an MR magnetic i7 film made of 81Ni 19Fe (permalloy) alloy with a thickness of 250, the actual value of α is approximately α = 0.017. Although there are some differences depending on the MR magnetic Vi of the MR magnetic sensitive part (5), film thickness and material, α = 0.0
It is about 5.
一方、この抵抗の固定骨Ｒｏは
Ｒｏ＝Ｒｉ （１＋ａΔｔ） ・・・
・（２＋（但し、Ｒｉは抵抗の初期値で、ａは温度係数
、ΔＬは温度変化分である）で与えられ、上述のＭＲ感
磁部（５）の例における温度係数ａの実測値は、ａ ＝
０．００２７／ ｄｅｇ程度である。このことは直流
磁界の検出において大きなノイズとなる。On the other hand, the fixed bone Ro of this resistance is Ro=Ri (1+aΔt)...
・(2+ (where Ri is the initial value of resistance, a is the temperature coefficient, and ΔL is the temperature change), and the actual measured value of the temperature coefficient a in the example of the MR magnetic sensing part (5) mentioned above is , a =
It is about 0.0027/deg. This results in large noise in detecting a DC magnetic field.
更に、この種のＭＲ型磁気ヘッド部による場合、上述し
たようにその温度係数が大きいために、例えばＭＲ感磁
部（５）への通電、或いはバイアス導体（３）へのバイ
アス電流等によって発生する熱が、ヘッド部の磁気記録
媒体との摺接によって不安定に放熱されてヘッドの温度
が変化する場合、大きなノイズ、所謂摺動ノイズを生ず
ることになる。Furthermore, in the case of this type of MR type magnetic head unit, since its temperature coefficient is large as mentioned above, the temperature coefficient is generated by, for example, energization to the MR magnetic sensing part (5) or bias current to the bias conductor (3). If this heat is radiated unstably due to the head's sliding contact with the magnetic recording medium and the temperature of the head changes, large noise, so-called sliding noise, will be generated.
又、第５図の構成における増幅器（１４）が低インピー
ダンス入力を呈する場合、ＭＲ感磁部（５）及びコンデ
ンサ（１６）から成る高域通過フィルタのカットオフ周
波数をｆｏとすると、このコンデンサ（１６）に必要な
容量Ｃは、ＲをＭＲ感磁部（５）の抵抗とすると、
（ω０＝２πｆｏ）となる。今、ＭＲ感磁部（５）が前
述した厚さ ２５０人のパーマロイより成り、その長さ
が５０μｍとなると、その抵抗Ｒは１０００程度となる
ので、ｆ ｏ ＝ １ ｋｌｌｚとすると、コンデンサ
（１６）としてはＣ＝１．３μＦという大きな値のもの
が必要となり、特にマルチトラック型のデジタルオーデ
ィオ信号用磁気ヘッド装置を構成する場合には問題とな
るものである。Furthermore, when the amplifier (14) in the configuration shown in FIG. The capacitance C required for 16) is (ω0=2πfo), where R is the resistance of the MR magnetic sensing part (5). Now, if the MR magnetic sensing part (5) is made of the above-mentioned permalloy with a thickness of 250 mm and its length is 50 μm, its resistance R will be about 1000, so if f o = 1 kllz, then the capacitor (16 ) is required to have a large value of C=1.3 .mu.F, which is particularly problematic when constructing a multi-track type magnetic head device for digital audio signals.
又、磁気回路における透磁率、特に比較的肉薄で断面積
が小さい磁性層（７）及び（８）における透磁率は、こ
れができるだけ大であることが望まれ、この透磁率は外
部磁界が零のとき最大となるので、上述したようなバイ
アス磁界を与えることは透磁率の低下を招来する。In addition, it is desirable that the magnetic permeability in the magnetic circuit, especially in the magnetic layers (7) and (8) which are relatively thin and have a small cross-sectional area, be as high as possible. Therefore, applying a bias magnetic field as described above will result in a decrease in magnetic permeability.
上述の直流バイアス式ＭＲ型磁気ヘッド装置は、有効ト
ラック幅が広く、狭トラツク化が容易であるという利点
がある反面、直線性が悪り、直流再生が困難で、摺動ノ
イズが大きく、バルクハウゼンノイズが大きく、出力の
ばらつきが大きいという欠点がある。The above-mentioned DC bias type MR magnetic head device has the advantage that it has a wide effective track width and can easily be narrowed, but it has poor linearity, difficulty in DC reproduction, large sliding noise, and bulk The disadvantages are that the Hausen noise is large and the output varies widely.
しかして、従来、特に出力信号の２次回υ＋ａ波歪を除
去するようにしたＭＲ型磁気ヘッド装置が提案されてい
る。以下に、第７図を参照して、かかる磁気ヘッド装置
について説明する。ヘッド部りには、中点が接地されて
、互いに特性の等しい２部分（５ａ） 、 （５ｂ）
から成るＭＲ感磁部（５）と、中点が接地されて、互い
に特性の等しい２部分（３ａ）（３ｂ）から成るバイア
ス導体（３］とから構成される。Therefore, an MR type magnetic head device has been proposed in which the second-order υ+a-wave distortion of the output signal is particularly removed. The magnetic head device will be described below with reference to FIG. The head part has two parts (5a) and (5b) whose midpoints are grounded and have the same characteristics.
and a bias conductor (3) consisting of two parts (3a) and (3b) having the same characteristics and whose midpoint is grounded.
ＭＲ感磁部（５）の両端に、互いに逆方向に、同じ検出
電流ｉＭＲを流すと共に、バイアス導体（３）の両端に
、互いに逆方向に、同じ直流電流ｉＢを流す。The same detection current iMR is made to flow in opposite directions to both ends of the MR magnetic sensing section (5), and the same DC current iB is made to flow in opposite directions to both ends of the bias conductor (3).
かくして、ＭＲ感部（５）の各部分（５ａ） 、 （
５ｂ）に、バイアス導体（３）の２部分（３ａ） 、
（３ｂ）への直流電流ｉＢの通電によって発生した磁
界と、ＭＲ感磁部（５）への検出電流１ＩｉＲの通電に
よって発生した磁界とによって、夫々互いに逆のバイア
ス磁界ＨＢが与えられた状態で、磁気媒体からの同じ信
号磁界Ｈ５が与えられる。そして、この信号磁界Ｈ５に
よる抵抗変化に基づ＜ＭＲ感磁部（５）の両端電圧、す
なわちＡ□、Ａ２点の電位の変化を、差動増幅″ｉ（１
り）に供給する。かくすると、点Ａｌ、Ａ２の出力電圧
は互いに逆相であるが、その２次同調波は同相であるか
ら、差動増幅器（１９）の出力側、即ち出力端子（１５
）には２次高調波の除去された、歪の少ない出力信号が
得られる。Thus, each part (5a), (
5b), two parts (3a) of the bias conductor (3),
(3b) and the magnetic field generated by applying a detection current 1IiR to the MR magnetic sensing part (5), a bias magnetic field HB opposite to each other is applied. , the same signal magnetic field H5 from the magnetic medium is applied. Based on the resistance change caused by this signal magnetic field H5, the voltage across the MR magnetic sensing section (5), that is, the change in the potential at points A□ and A2, is differentially amplified ``i(1
supply). In this way, the output voltages at points Al and A2 are in opposite phases to each other, but their secondary harmonic waves are in phase.
), an output signal with less distortion is obtained from which the second harmonic has been removed.
しかしながら、第７図の従来のＭＲ型磁気ヘッド装置は
、次のよう欠点を有している。ＭＲ感磁部（５）の２部
分（５ａ） 、 （５ｂ）の特性を商粕度を以って等
しくすることが困難であり、又、ＭＲ感磁部（５）の２
部分（５ａ） 、 （５ｂ）への信号磁界を高精度を
以って等しくするのが困難であるので、出力信号にオフ
セットが生じる。 ＭＲ感磁部（５）の２部分の境界に
不感帯ができるため、ヘッド部りの幅をあまり狭くする
ことができず、多チャンネル化が困難となる。ヘッド部
りからの引出線の本数が増加し、多チャンネル化が困難
となる。However, the conventional MR type magnetic head device shown in FIG. 7 has the following drawbacks. It is difficult to make the characteristics of the two parts (5a) and (5b) of the MR magnetic sensing part (5) equal in terms of commercial graininess.
Since it is difficult to equalize the signal magnetic fields to portions (5a) and (5b) with high precision, an offset occurs in the output signal. Since a dead zone is formed at the boundary between the two parts of the MR magnetic sensing part (5), the width of the head part cannot be made very narrow, making it difficult to increase the number of channels. The number of lead wires from the head increases, making it difficult to create multiple channels.
かかる点に鑑み、本発明は上述の欠点を悉く除去し、出
力信号の２次高調波を除去して、歪を少な（することの
できるＭＲ型磁気ヘッド装置を提末しようとするもので
ある。In view of this, the present invention aims to eliminate all of the above-mentioned drawbacks, remove the second harmonic of the output signal, and provide an MR type magnetic head device that can reduce distortion. .
本発明によるＭＲ型磁気ヘッド装置は、信号磁界の与え
られる磁気抵抗効果感磁部（５）と、この磁気抵抗効果
感磁部（５）に所定周波数の矩形波バイアス磁界を与え
るバイアス磁界発生手段１３）、 （２０） 。The MR type magnetic head device according to the present invention includes a magnetoresistive magnetic sensing part (5) to which a signal magnetic field is applied, and a bias magnetic field generating means for applying a rectangular wave bias magnetic field of a predetermined frequency to the magnetoresistive magnetic sensing part (5). 13), (20).
（２１）と、磁気抵抗効果感磁部（５）から信号磁界に
応じた出力信号を取付ず信号取出手段（２２）と、この
信号取出手段（２２）よりの出力信号を供給して、矩形
波バイアス磁界に同期して、その正相及び逆相の信号を
交互に出力する位相切換回路（２３）と、この位相切換
回路（２３）の出力信号の供給されるローバスフィルタ
（２６）とを存することを特徴とするものである。(21), a signal extraction means (22) without attaching an output signal corresponding to the signal magnetic field from the magnetoresistive magnetic sensing part (5), and a rectangular shape by supplying the output signal from the signal extraction means (22). A phase switching circuit (23) that alternately outputs signals of positive phase and negative phase in synchronization with the wave bias magnetic field, and a low-pass filter (26) to which the output signal of this phase switching circuit (23) is supplied. It is characterized by the following.
かかる本発明によれば、ＭＲ感磁部（５）に、矩形波バ
イアス磁界及び信号磁界の重畳磁界が与えられ、ＭＲ感
磁部（５）から得られた出力電圧の位相を、位相切換回
路（２３）によって、矩形波バイアス磁界に同期して、
正相、逆相に交互に切換えるので、ローバスフィルタ（
２６）の出力側には信号磁界に対応した、２次高調波の
除去された、歪のない信号が出力される。According to the present invention, a superimposed magnetic field of a rectangular bias magnetic field and a signal magnetic field is applied to the MR magnetic sensing section (5), and the phase of the output voltage obtained from the MR magnetic sensing section (5) is changed by the phase switching circuit. By (23), in synchronization with the square wave bias magnetic field,
Since it switches alternately between positive phase and negative phase, a low-pass filter (
26) outputs an undistorted signal corresponding to the signal magnetic field, from which the second harmonic has been removed.
以下に第１図を参照して、本発明の一実施例を詳細に説
明する。ＭＲ型磁気ヘッド部りの構成は、第４図及び第
５図と同様である。（２０）は矩形波発生器で、その矩
形波信号の周波数を信号磁界（直流を可とする）の最高
周波数の３倍以上に選定する。この矩形波信号をバッフ
ァ （電流ドライバ） （２１）に供給し、その出力
によりバイアス導体（３）に矩形波のバイアス電流ＬＢ
を流すようにする。An embodiment of the present invention will be described in detail below with reference to FIG. The configuration of the MR type magnetic head section is the same as that shown in FIGS. 4 and 5. (20) is a rectangular wave generator, and the frequency of the rectangular wave signal is selected to be at least three times the highest frequency of the signal magnetic field (direct current is allowed). This rectangular wave signal is supplied to a buffer (current driver) (21), and its output causes a rectangular bias current LB to be applied to the bias conductor (3).
to flow.
かくして、ＭＲ感磁部（５）に、バイアス導体（３）へ
の矩形波電流ｉＢの通電によって発生した矩形波磁界と
、ＭＲ感磁部（５）への検出電流ｉ １１Ｈの通電によ
って発生した磁界とによってバイアス磁界ＨＲが与えら
れた状態で、前述した磁気媒体からの信号磁界Ｈ，が与
えられる。そして、この信号磁界Ｈ５による抵抗変化に
基づ＜ＭＲ感磁部（５）の両端電圧、すなわちＡ点の電
位の変化を、信号取出手段（２２）によって取出し、即
ち、低域阻止用コンデンサ（１６）を介して増幅器（１
４）に供給して増幅する。増幅器（１４）の出力を位相
切換回路（２３）に供給して、上述の矩形波発生器（２
０）よりの矩形波信号により、増幅器（１４）よりの出
力を正相、逆相に交互に位相切換えする。即ち、増幅器
（１４）の出力と、その出力をインバータ（２４）に供
給して位相反転した出力とを、矩形波信号によって制御
されるスイッチ（２５）によって切換えて、ローバスフ
ィルタ（２６）に供給し、出力端子（１５）より信号磁
界Ｈ５に応じた信号出力を得るようにする。Thus, a rectangular wave magnetic field is generated in the MR magnetic sensing part (5) by the application of the rectangular wave current iB to the bias conductor (3), and a rectangular wave magnetic field is generated by the application of the detection current i11H to the MR magnetic sensing part (5). The signal magnetic field H from the magnetic medium described above is applied while the bias magnetic field HR is applied by the magnetic field. Then, based on the resistance change caused by this signal magnetic field H5, the voltage across the MR magnetic sensing section (5), that is, the change in the potential at point A, is extracted by the signal extraction means (22), that is, the low-frequency blocking capacitor ( 16) through the amplifier (1
4) and amplify it. The output of the amplifier (14) is supplied to the phase switching circuit (23) to generate the above-mentioned square wave generator (2).
The phase of the output from the amplifier (14) is alternately switched between positive phase and negative phase by the rectangular wave signal from 0). That is, the output of the amplifier (14) and the output whose phase is inverted by supplying the output to the inverter (24) are switched by a switch (25) controlled by a rectangular wave signal, and the output is sent to a low-pass filter (26). A signal output corresponding to the signal magnetic field H5 is obtained from the output terminal (15).
次に、この第１図の磁気ヘッド装置の動作を第２図をも
参照して説明する。第２図ＡにＭＲ感磁部（５）の磁界
対抵抗の特性曲線を示す。ＭＲ感磁部（５）に、第２図
Ｂに示す、信号磁界１（Ｓ（ｔｌ及びレベルの比較的大
きな矩形波バイアス磁界ＨＢ（ｔ）の重畳磁界が与えら
れるので、ＭＲ感磁部（５）からは第２図Ｃに示す如き
正負に非対称な出力電圧Ｖ （ｔｌが得られる。そして
、この出力電圧Ｖ （ｔｌを位相切換回路（２３）によ
って、矩形波バイアス磁界ＨＢ （ｔ）に同期して、正
相、逆相の交互の切換えを行うと、ローバスフィルタ（
２６）の出力側、即ち出力端子（１５）には第２１ｆｆ
ｌＢの信号磁界Ｈ５（ｔｌに対応した信号出力Ｖ ｏ
（ｔｌが出力される。Next, the operation of the magnetic head device shown in FIG. 1 will be explained with reference to FIG. 2 as well. FIG. 2A shows a characteristic curve of magnetic field versus resistance of the MR magnetic sensing part (5). Since the MR magnetic sensing part (5) is given a superimposed magnetic field of the signal magnetic field 1 (S(tl) and the rectangular wave bias magnetic field HB(t) with a relatively large level as shown in FIG. 2B, the MR magnetic sensing part (5) 5), an output voltage V (tl) which is asymmetric in the positive and negative directions as shown in FIG. When the positive phase and negative phase are switched alternately in synchronization, the low-pass filter (
26), that is, the output terminal (15), the 21st ff
Signal magnetic field H5 of lB (signal output V o corresponding to tl
(tl is output.
尚、ヘッド部りの構造は、第４図の構造のものの他、第
３図の構造のものも可能である。即ち、第３図のヘッド
部りは、フェライトの如き高透磁率の磁性体（２７）
、 （２Ｂ）間に、非磁性層（２９）を介してバイア
ス導体（３）及びこれに対向するＭＲ感磁部（５）を配
し、全体の端面を研摩してテープ対接面としたものであ
る。In addition to the structure shown in FIG. 4, the structure of the head portion may also be the structure shown in FIG. 3. That is, the head portion in FIG. 3 is made of a magnetic material (27) with high magnetic permeability such as ferrite.
, (2B), a bias conductor (3) and an MR magnetic sensing part (5) facing the bias conductor (3) were arranged through a non-magnetic layer (29), and the entire end surface was polished to form a tape facing surface. It is something.
尚、再生信号はデジタルオーディオ／ビデオ信号又はア
ナログオーディオ／ビデオ信号が可能である。Note that the reproduction signal can be a digital audio/video signal or an analog audio/video signal.
上述せる本発明によれば、出力信号にオフセットが生ぜ
ず、多チャンネル化が容易であって、出力信号の２次１
ｔｌｉ １ｔｌｆａ波を除去して、歪を少なくすること
のできるＭＲ型磁気ヘッド装置を得ることができる。According to the present invention described above, an offset does not occur in the output signal, multi-channeling is easy, and the secondary
It is possible to obtain an MR type magnetic head device that can reduce distortion by removing tli 1tlfa waves.
又、テープに対する摺動によるノイズが発生し難り、信
号取出手段のコンデンサの容量が小さくても、直流信号
までも取出すことのできるＭＲ型磁気ヘッド装置を得る
ことができる。Further, it is possible to obtain an MR type magnetic head device in which noise due to sliding on the tape is less likely to occur and even a DC signal can be extracted even if the capacitance of the capacitor of the signal extraction means is small.
第５図のＭＲ型磁気ヘッド装置に於いて、バイアス導体
（３）に流すバイアス電流を矩形波電流とし、信号取出
手段よりの信号出力をバイアス電流に同期した矩形波信
号と掛算し、その出力をローバスフィルタに供給して、
信号磁界に対応した信号出力を得ることも考えられるが
、その場合は次のような欠点がある。In the MR type magnetic head device shown in Fig. 5, the bias current flowing through the bias conductor (3) is a rectangular wave current, the signal output from the signal extraction means is multiplied by a rectangular wave signal synchronized with the bias current, and the resulting output is is supplied to the low-pass filter,
Although it is possible to obtain a signal output corresponding to the signal magnetic field, there are the following drawbacks in that case.
ＭＲ感磁部（５）の抵抗の固定分の変化による信号成分
を除去するフィルタを設けるか、その抵抗の固定部と同
じ抵抗値の低抗器に矩形波電流を流し、その端電圧に応
じた信号を信号出力から差引いて１１−抗の固定分の変
化による信号成分をキャンセルする必要がある。ダイナ
ミックレンジの広い増幅器が必要である。−ローバスフ
ィルタとして、遮断特性の急峻なものが必要となる。し
かし、本発明の場合は、そのような欠点が無い。Either provide a filter to remove signal components caused by changes in the fixed resistance of the MR magnetic sensing part (5), or run a rectangular wave current through a low resistor with the same resistance value as the fixed part of the resistance, and It is necessary to subtract the signal from the signal output to cancel the signal component due to the fixed change in the resistor. An amplifier with a wide dynamic range is required. -A low-pass filter with steep cutoff characteristics is required. However, the present invention does not have such drawbacks.
第１図は本発明の一実施例を示す回路図、第２図はその
動作説明に供する特性曲線・波形図、第３図は本発明の
一実施例のヘッド部の構成例を示す断面図、第４図は従
来の磁気抵抗効果型磁気ヘッド装置のヘッド部の構成を
示すｌｌｉ面図、第５図は従来の磁気抵抗効果型磁気ヘ
ッド装置を示す回路図、第６図はその説明に供する特性
曲線図、第７図は従来の他の磁気抵抗効果型磁気ヘッド
装置を示す回路図である。
（３）はバイアス導体、（５）は磁気抵抗効果感磁部、
（２２）は信号取出手段、（２３）は位相切換回路であ
る。
第４図
第５図Fig. 1 is a circuit diagram showing an embodiment of the present invention, Fig. 2 is a characteristic curve/waveform diagram for explaining its operation, and Fig. 3 is a sectional view showing an example of the structure of the head portion of an embodiment of the present invention. , FIG. 4 is a lli plan view showing the configuration of the head section of a conventional magnetoresistive magnetic head device, FIG. 5 is a circuit diagram showing a conventional magnetoresistive magnetic head device, and FIG. 6 is an explanation thereof. FIG. 7 is a circuit diagram showing another conventional magnetoresistive magnetic head device. (3) is a bias conductor, (5) is a magnetoresistive effect magnetic part,
(22) is a signal extraction means, and (23) is a phase switching circuit. Figure 4 Figure 5
Claims (1)
抗効果感磁部に所定周波数の矩形波バイアス磁界を与え
るバイアス磁界発生手段と、上記磁気抵抗効果感磁部か
ら上記信号磁界に応じた出力信号を取出す信号取出手段
と、該信号取出手段よりの出力信号を供給して、上記矩
形波バイアス磁界に同期して、その正相及び逆相の信号
を交互に出力する位相切換回路と、該位相切換回路の出
力信号の供給されるローバスフィルタとを有することを
特徴とする磁気抵抗効果型磁気ヘッド装置。a magnetoresistive magnetic sensing section to which a signal magnetic field is applied; bias magnetic field generating means for applying a rectangular wave bias magnetic field of a predetermined frequency to the magnetoresistive magnetic sensing section; a signal extracting means for extracting an output signal; a phase switching circuit for supplying the output signal from the signal extracting means and alternately outputting the positive phase and negative phase signals in synchronization with the rectangular wave bias magnetic field; A magnetoresistive magnetic head device comprising: a low-pass filter to which an output signal of the phase switching circuit is supplied.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17647684A JPS6154005A (en) | 1984-08-24 | 1984-08-24 | Magneto-resistance effect type magnetic head device |
| US06/705,706 US4703378A (en) | 1984-03-01 | 1985-02-26 | Magnetic transducer head utilizing magnetoresistance effect |
| CA000475257A CA1235482A (en) | 1984-03-01 | 1985-02-27 | Magnetic transducer head utilizing magnetoresistance effect |
| DE8585102282T DE3585959D1 (en) | 1984-03-01 | 1985-02-28 | MAGNETIC CONVERTER HEAD USING THE MAGNETIC RESISTANCE EFFECT. |
| DE3588065T DE3588065T2 (en) | 1984-03-01 | 1985-02-28 | Magnetic transducer head device using the magnetoresistance effect. |
| EP93100342A EP0544642B1 (en) | 1984-03-01 | 1985-02-28 | Magnetic transducer head apparatus utilizing the magnetoresistance effect |
| DE3587992T DE3587992T2 (en) | 1984-03-01 | 1985-02-28 | Magnetic transducer head using a magnetoresistance effect. |
| EP85102282A EP0154307B1 (en) | 1984-03-01 | 1985-02-28 | Magnetic transducer head utilizing the magnetoresistance effect |
| EP90123594A EP0421489B1 (en) | 1984-03-01 | 1985-02-28 | Magnetic transducer head utilizing the magnetoresistance effect |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17647684A JPS6154005A (en) | 1984-08-24 | 1984-08-24 | Magneto-resistance effect type magnetic head device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6154005A true JPS6154005A (en) | 1986-03-18 |
| JPH0532804B2 JPH0532804B2 (en) | 1993-05-18 |
Family
ID=16014335
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17647684A Granted JPS6154005A (en) | 1984-03-01 | 1984-08-24 | Magneto-resistance effect type magnetic head device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6154005A (en) |
-
1984
- 1984-08-24 JP JP17647684A patent/JPS6154005A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0532804B2 (en) | 1993-05-18 |
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