JP5086605B2 - Moving body detection device - Google Patents

Moving body detection device Download PDF

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JP5086605B2
JP5086605B2 JP2006292095A JP2006292095A JP5086605B2 JP 5086605 B2 JP5086605 B2 JP 5086605B2 JP 2006292095 A JP2006292095 A JP 2006292095A JP 2006292095 A JP2006292095 A JP 2006292095A JP 5086605 B2 JP5086605 B2 JP 5086605B2
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利尚 木戸
誠二 福岡
進 原谷
仁 山口
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Description

本発明は、磁性材移動体の移動に伴う磁界変化を検出する移動体検出装置に係り、特に工業用工作機械や、自動車のエンジン等に用いられる軟磁性体歯車の回転情報を検出する場合、あるいは磁性粉等からなる磁性層パターン（磁性粉又は磁性膜によるパターン）が付着した媒体の情報を検出する場合等に用いて好適な移動体検出装置に関するものである。   The present invention relates to a moving body detection device for detecting a magnetic field change accompanying the movement of a magnetic material moving body, particularly when detecting rotation information of a soft magnetic gear used for industrial machine tools, automobile engines, etc. Alternatively, the present invention relates to a moving body detection apparatus suitable for use in detecting information on a medium to which a magnetic layer pattern (pattern made of magnetic powder or magnetic film) made of magnetic powder or the like is attached.

従来のスピンバルブ型巨大磁気抵抗素子（以下、ＳＶ−ＧＭＲ素子）を用いた移動体検出装置は、ＳＶ−ＧＭＲ素子の急峻な磁気特性を利用し、高感度な検出装置としていた。ＳＶ−ＧＭＲ素子を用いた移動体検出装置の１例として下記特許文献１がある。   A conventional mobile object detection device using a spin-valve type giant magnetoresistive element (hereinafter referred to as an SV-GMR element) is a highly sensitive detection apparatus utilizing the steep magnetic characteristics of the SV-GMR element. As an example of a moving object detection apparatus using an SV-GMR element, there is Patent Document 1 below.

特開２００５−２３３７９５号公報 この種の移動体検出装置で用いられるＳＶ−ＧＭＲ素子の模式的な膜構成及び磁気特性を図７に示す。ＳＶ−ＧＭＲ素子は、磁化方向が一方向に固定された強磁性体のピン層と、電流が主として流れる非磁性体を介して前記ピン層に積層された強磁性体のフリー層とからなる磁気抵抗効果膜を有し、ピン層は外部磁界（外部磁束）によって磁化方向は変化せず、フリー層は外部磁界（外部磁束）の方向に磁化される。ここで、磁気抵抗効果膜におけるピン層の磁化方向とフリー層の磁化方向（つまり外部磁界の方向）とが直交しているとき（図７（ａ）のθ＝０のとき）、抵抗変化率（ΔＲ／Ｒ）は０である。ピン層の磁化方向とフリー層の磁化方向（つまり外部磁界Ｈの方向）とが平行であるが向きが逆のとき、つまり反平行のとき、抵抗変化率はプラスとなり、図７（ａ）の高抵抗状態となる。また、ピン層の磁化方向とフリー層の磁化方向（つまり外部磁界Ｈの方向）とが平行でかつ向きが同じとき、つまり順平行のとき、抵抗変化率はマイナスとなり、図７（ｂ）の低抵抗状態となる。FIG. 7 shows a schematic film configuration and magnetic characteristics of an SV-GMR element used in this type of moving body detection apparatus. The SV-GMR element includes a magnetic pinned layer whose magnetization direction is fixed in one direction, and a ferromagnetic free layer stacked on the pinned layer via a nonmagnetic material through which a current mainly flows. It has a resistance effect film, the magnetization direction of the pinned layer is not changed by an external magnetic field (external magnetic flux), and the free layer is magnetized in the direction of the external magnetic field (external magnetic flux). Here, when the magnetization direction of the pinned layer and the magnetization direction of the free layer (that is, the direction of the external magnetic field) in the magnetoresistive effect film are orthogonal (when θ = 0 in FIG. 7A), the resistance change rate (ΔR / R) is zero. When the magnetization direction of the pinned layer and the magnetization direction of the free layer (that is, the direction of the external magnetic field H) are parallel but opposite to each other, that is, when they are antiparallel, the rate of change in resistance becomes positive, as shown in FIG. High resistance state. When the magnetization direction of the pinned layer and the magnetization direction of the free layer (that is, the direction of the external magnetic field H) are parallel and in the same direction, that is, in the forward parallel direction, the rate of change in resistance becomes negative, as shown in FIG. It becomes a low resistance state.

また、ＳＶ−ＧＭＲ素子において、外部磁界が飽和磁界Ｈｋに達するまでの非飽和領域では外部磁界変化に対して抵抗変化率は直線的に大きく変化し、外部磁界が飽和磁界Ｈｋ以上となると飽和状態となって抵抗変化率は略一定となる特性である。飽和磁界Ｈｋは微弱磁界感度の目安になるものであり、ＳＶ−ＧＭＲ素子の飽和磁界Ｈｋにばらつきがあると、飽和磁界Ｈｋ未満の外部磁界と抵抗変化率との関係を示す直線の傾きが変化してしまう。例えば図８のＳＶ−ＧＭＲ素子の入出力変換図において、直線Ｌ１に対して直線Ｌ２の傾きが倍（ＳＶ−ＧＭＲ素子の感度が２倍）であると、入力信号である磁界変化に対して抵抗変化は２倍（換言すれば出力信号は２倍）となる。つまり、ＳＶ−ＧＭＲ素子の非飽和領域のリニアな特性を利用して微小外部磁界を検出する場合、ＳＶ−ＧＭＲ素子の飽和磁界Ｈｋのばらつき（感度ばらつき）が検出出力のばらつきを引き起こしていた。   In the SV-GMR element, in the non-saturation region until the external magnetic field reaches the saturation magnetic field Hk, the resistance change rate greatly changes linearly with respect to the change in the external magnetic field, and when the external magnetic field exceeds the saturation magnetic field Hk, the saturation state Thus, the resistance change rate is a characteristic that is substantially constant. The saturation magnetic field Hk is a measure of weak magnetic field sensitivity. If the saturation magnetic field Hk of the SV-GMR element varies, the slope of the straight line indicating the relationship between the external magnetic field below the saturation magnetic field Hk and the resistance change rate changes. Resulting in. For example, in the input / output conversion diagram of the SV-GMR element in FIG. 8, if the slope of the straight line L2 is double that of the straight line L1 (the sensitivity of the SV-GMR element is twice), the change in the magnetic field that is the input signal The resistance change is doubled (in other words, the output signal is doubled). That is, when detecting a minute external magnetic field using the linear characteristic of the non-saturated region of the SV-GMR element, the variation (sensitivity variation) of the saturation magnetic field Hk of the SV-GMR element causes a variation in detection output.

従来の移動体検出装置は、上記の飽和磁界Ｈｋのばらつきに起因する検出出力のばらつきに対する配慮がなく、例えば回転検出の用途に使用する場合には、検出出力のばらつきは回転情報のばらつきに繋がり、検出出力の安定した移動体検出装置を無調整で作製することが難しかった。   The conventional moving body detection device does not consider the variation in the detection output due to the variation in the saturation magnetic field Hk. For example, when used for the purpose of rotation detection, the variation in the detection output leads to the variation in the rotation information. Therefore, it has been difficult to produce a moving body detection device with stable detection output without adjustment.

また、移動体検出装置が、例えば、軟磁性歯車と、この歯車に近接配置されるＳＶ−ＧＭＲ素子と、これにバイアス磁界を印加するバイアス磁石とを有する回転検出装置である場合、前記歯車とＳＶ−ＧＭＲ素子間の必要なギャップを確保しつつ、微小磁界変化での検出出力を高めるためには、バイアス磁石による発生磁界を高めなければならない。この場合、サイズの大きな磁石の使用や、磁石材料を変更しなければならず、小型化やコスト低減の妨げとなっていた。   When the moving body detection device is, for example, a rotation detection device having a soft magnetic gear, an SV-GMR element disposed close to the gear, and a bias magnet for applying a bias magnetic field thereto, the gear In order to increase the detection output with a minute magnetic field change while securing the necessary gap between the SV-GMR elements, the magnetic field generated by the bias magnet must be increased. In this case, it is necessary to use a large magnet or change the magnet material, which hinders downsizing and cost reduction.

上記の点に鑑み、本発明者は、ＳＶ−ＧＭＲ素子の磁気抵抗効果膜パターンの長さ及び幅と飽和磁界Ｈｋとの関係を考察し、その結果、飽和磁界Ｈｋが小さく高感度で、かつ飽和磁界Ｈｋの変化が少ない領域を見いだした。   In view of the above points, the present inventor considered the relationship between the length and width of the magnetoresistive effect film pattern of the SV-GMR element and the saturation magnetic field Hk, and as a result, the saturation magnetic field Hk was small and high sensitivity. An area where the change of the saturation magnetic field Hk was small was found.

すなわち、本発明は、ＳＶ−ＧＭＲ素子を用いた移動体検出装置において、ＳＶ−ＧＭＲ素子の磁気抵抗効果膜パターンのピン層磁化方向の幅を２０μｍ以上とすることで、検出出力のばらつきが少なく、感度の高い移動体検出装置を提供することを目的とする。   That is, according to the present invention, in a moving body detection apparatus using an SV-GMR element, the variation in detection output is reduced by setting the width in the pinned layer magnetization direction of the magnetoresistive effect film pattern of the SV-GMR element to 20 μm or more. An object of the present invention is to provide a mobile object detection device with high sensitivity.

本発明のその他の目的や新規な特徴は後述の実施の形態において明らかにする。   Other objects and novel features of the present invention will be clarified in embodiments described later.

上記目的を達成するために、本発明のある態様の移動体検出装置は、
磁性材移動体と、磁界発生手段と、少なくとも１つのスピンバルブ型巨大磁気抵抗素子（ＳＶ−ＧＭＲ素子）とを有し、
前記磁界発生手段は、前記スピンバルブ型巨大磁気抵抗素子の感磁面位置において前記感磁面と略垂直となるバイアス磁界を発生し、
前記スピンバルブ型巨大磁気抵抗素子が１対又は複数対あり、対をなす前記スピンバルブ型巨大磁気抵抗素子のピン層磁化方向が互いに前記磁性材移動体の移動方向に対し、略順方向と略逆方向を向くように配置され、
前記磁性材移動体の移動に伴って、前記スピンバルブ型巨大磁気抵抗素子の感磁面位置における前記バイアス磁界が、前記ピン層磁化方向と順平行又は反平行な成分を有する状態と、前記感磁面と略垂直な状態との間で変化し、
前記ＳＶ−ＧＭＲ素子が有する磁気抵抗効果膜パターンのピン層磁化方向の幅を２０μｍ以上としたことを特徴としている。 In order to achieve the above object, a mobile object detection device according to an aspect of the present invention includes:
A magnetic material moving body, a magnetic field generating means, and at least one spin-valve giant magnetoresistive element (SV-GMR element);
The magnetic field generating means generates a bias magnetic field that is substantially perpendicular to the magnetosensitive surface at the magnetosensitive surface position of the spin valve type giant magnetoresistive element,
The spin valve giant magnetoresistive element has one or more pairs, and the pin layer magnetization directions of the paired spin valve giant magnetoresistive elements are substantially forward and substantially relative to the moving direction of the magnetic material moving body. Placed in the opposite direction,
As the magnetic material moving body moves, the bias magnetic field at the position of the magnetosensitive surface of the spin-valve giant magnetoresistive element has a component that is forward-parallel or anti-parallel to the pinned layer magnetization direction; Changes between the magnetic surface and the almost perpendicular state,
The magnetoresistive effect film pattern of the SV-GMR element has a pinned layer magnetization direction width of 20 μm or more.

前記移動体検出装置において、前記磁性材移動体が少なくとも１つの凸部又は凹部を有してもよい。 In the moving object detection apparatus, the magnetic material moving body may have at least one projection or recess.

前記移動体検出装置において、前記磁性材移動体が磁性粉付着媒体又は磁性膜付着媒体であってもよい。 In the moving body detection apparatus, the magnetic material moving body may be a magnetic powder adhesion medium or a magnetic film adhesion medium.

前記ＳＶ−ＧＭＲ素子が磁気抵抗効果膜パターンの直列接続、並列接続の一方又は両方を有するものであってもよい。   The SV-GMR element may have one or both of series connection and parallel connection of magnetoresistive film patterns.

前記ＳＶ−ＧＭＲ素子が同一基板上に一対又は複数対形成され、対をなすＳＶ−ＧＭＲ素子が磁気抵抗効果膜パターンを含むダブルミアンダパターンで構成されていてもよい。   A pair or a plurality of SV-GMR elements may be formed on the same substrate, and the paired SV-GMR elements may be formed of a double meander pattern including a magnetoresistive film pattern.

本発明に係る移動体検出装置によれば、ＳＶ−ＧＭＲ素子の飽和磁界Ｈｋを小さく、かつ飽和磁界Ｈｋのばらつきを少なくできるので、検出出力のばらつきを低減し、感度の向上を図ることができる。また、ＳＶ−ＧＭＲ素子を高感度にすることで、磁界発生手段（バイアス磁石等）は大型化する必要がなくなり、移動体検出装置の小型化にも寄与できる。   According to the moving body detection apparatus of the present invention, the saturation magnetic field Hk of the SV-GMR element can be reduced and the variation of the saturation magnetic field Hk can be reduced, so that the variation in detection output can be reduced and the sensitivity can be improved. . Further, by making the SV-GMR element highly sensitive, it is not necessary to increase the size of the magnetic field generating means (such as a bias magnet), which can contribute to the downsizing of the moving body detection apparatus.

また、前記ＳＶ−ＧＭＲ素子が磁気抵抗効果膜パターンの直列接続、並列接続の一方又は両方を有する構成とした場合、抵抗値が調整可能となり、増幅回路等との整合が容易となる。   Further, when the SV-GMR element has a configuration in which one or both of the magnetoresistive effect film patterns are connected in series or in parallel, the resistance value can be adjusted, and matching with an amplifier circuit or the like is facilitated.

さらに、対をなしたＳＶ−ＧＭＲ素子を、磁気抵抗効果膜パターンを含むダブルミアンダパターンで構成する場合、ＳＶ−ＧＭＲ素子群の集積度を向上させて小型化を図ることができる。   Furthermore, when the paired SV-GMR elements are configured with a double meander pattern including a magnetoresistive film pattern, the degree of integration of the SV-GMR element group can be improved and the size can be reduced.

以下、本発明を実施するための最良の形態として、移動体検出装置の実施の形態を図面に従って説明する。   Hereinafter, as a best mode for carrying out the present invention, an embodiment of a moving body detection apparatus will be described with reference to the drawings.

図１乃至図３で本発明に係る移動体検出装置の実施の形態１を説明する。実施の形態１は、磁性材移動体として軟磁性体歯車の回転検出を行う回転センサを構成した場合を示す。   Embodiment 1 of the moving body detection apparatus according to the present invention will be described with reference to FIGS. Embodiment 1 shows a case where a rotation sensor for detecting rotation of a soft magnetic gear is configured as a magnetic material moving body.

図１（Ａ）において、１は軟磁性体歯車であり、外周面に凹凸を有する（例えば一定配列ピッチＰで凸部２を有する）ものである。   In FIG. 1A, reference numeral 1 denotes a soft magnetic gear, which has irregularities on the outer peripheral surface (for example, has convex portions 2 with a constant arrangement pitch P).

また、軟磁性体歯車１の外周面に対向するように、４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４が固定配置され、これらの背後にバイアス磁界印加用のバイアス磁石５が固定配置されて、４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４を磁気バイアスするようになっている。この場合、４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４の配列方向は軟磁性体歯車１の移動方向（回転方向）に対して略垂直方向で歯車１の厚み方向に直線的に配置されている。   Further, four SV-GMR elements R1, R2, R3, R4 are fixedly arranged so as to face the outer peripheral surface of the soft magnetic gear 1, and a bias magnet 5 for applying a bias magnetic field is fixedly arranged behind them. Thus, the four SV-GMR elements R1, R2, R3, and R4 are magnetically biased. In this case, the arrangement direction of the four SV-GMR elements R1, R2, R3, and R4 is substantially perpendicular to the moving direction (rotating direction) of the soft magnetic gear 1 and is linearly arranged in the thickness direction of the gear 1. Has been.

本実施の形態では、磁性材移動体である軟磁性体歯車１で変化された磁界に対応して抵抗値が変化するＳＶ−ＧＭＲ素子を用いており、その飽和磁界Ｈｋが安定となる条件を磁気抵抗効果膜パターンのピン層磁化方向と直交する方向の長さとピン層磁化方向の幅とを変化させて求めた。   In the present embodiment, the SV-GMR element whose resistance value changes in response to the magnetic field changed by the soft magnetic gear 1 that is a magnetic material moving body is used, and the condition that the saturation magnetic field Hk becomes stable is used. The magnetoresistive effect film pattern was obtained by changing the length in the direction orthogonal to the pinned layer magnetization direction and the width of the pinned layer magnetization direction.

図２（Ａ）,（Ｂ）,（Ｃ）は、ＳＶ−ＧＭＲ素子の模式的拡大図であり、ＳＶ−ＧＭＲ素子は基板１０にＡｕ電極パッド１１の対を形成し、その電極パッド１１の延長リード部１１ａ間に磁気抵抗効果膜の直線状パターン１２が形成され、延長リード部１１ａに接続されている。そして、図２（Ａ）では磁気抵抗効果膜パターン１２のピン層磁化方向と直交する方向の長さを１２０μｍ、同図（Ｂ）では長さを６０μｍ、同図（Ｃ）では長さを３０μｍとして、それぞれピン層磁化方向の幅を２μｍから１２０μｍまで変化させて飽和磁界Ｈｋを測定した結果を図３に示す。   2A, 2 </ b> B, and 2 </ b> C are schematic enlarged views of the SV-GMR element. The SV-GMR element forms a pair of Au electrode pads 11 on the substrate 10. A linear pattern 12 of a magnetoresistive film is formed between the extended lead portions 11a and is connected to the extended lead portion 11a. 2A, the length of the magnetoresistive effect film pattern 12 in the direction orthogonal to the pinned layer magnetization direction is 120 μm, the length in FIG. 2B is 60 μm, and the length in FIG. 2C is 30 μm. FIG. 3 shows the result of measuring the saturation magnetic field Hk by changing the width in the pinned layer magnetization direction from 2 μm to 120 μm.

図３の測定結果を見ると、ピン層磁化方向のパターン幅を変化させることにより、微弱磁界感度の目安となる飽和磁界Ｈｋが調整できることが明らかである。このとき、ピン層磁化方向と直交する方向のパターン長さは飽和磁界Ｈｋに殆ど関係しない（長さを３０〜１２０μｍに変化させても曲線はほぼ重なっている）。図３より飽和磁界Ｈｋが小さく（感度が高く）かつ飽和磁界Ｈｋのばらつきの小さいパターン幅を求めると（Ｈｋ−線幅曲線を３本の直線で近似して求めると）、２０μｍ以上となる。２０μｍ以上の線幅では、飽和磁界Ｈｋは１０〜１５Ｏｅ｛＝（１／４π）×１０３Ａ／ｍ｝の範囲内で安定する。 From the measurement result of FIG. 3, it is clear that the saturation magnetic field Hk that is a measure of the weak magnetic field sensitivity can be adjusted by changing the pattern width in the pinned layer magnetization direction. At this time, the pattern length in the direction orthogonal to the pinned layer magnetization direction has almost no relation to the saturation magnetic field Hk (the curves are almost overlapped even if the length is changed from 30 to 120 μm). If the pattern width with a small saturation magnetic field Hk (high sensitivity) and a small variation in the saturation magnetic field Hk is obtained from FIG. At a line width of 20 μm or more, the saturation magnetic field Hk is stable within a range of 10 to 15 Oe {= (¼π) × 10 3 A / m}.

図３の結果から、図１で使用する４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４では、その磁気抵抗効果膜パターンのピン層磁化方向の幅を２０μｍ以上に設定する。ピン層磁化方向の幅の上限は、対をなす電極パッド１１の幅（本例では例えば１２０μｍ程度）で通常制約される。パターン幅２０μｍ以上に設定すれば、数μｍのパターン幅変化では飽和磁界Ｈｋが殆ど変化せず、ばらつきの少ないＳＶ−ＧＭＲ素子が得られる。また、１例として、従来のパターン幅９μｍのＳＶ−ＧＭＲ素子と比較して飽和磁界Ｈｋは約半分となり、ＳＶ−ＧＭＲ素子の非飽和領域を利用する場合、感度は約２倍に向上する。   From the results of FIG. 3, in the four SV-GMR elements R1, R2, R3, R4 used in FIG. 1, the width of the magnetoresistive film pattern in the pinned layer magnetization direction is set to 20 μm or more. The upper limit of the width in the pinned layer magnetization direction is usually restricted by the width of the paired electrode pads 11 (for example, about 120 μm in this example). If the pattern width is set to 20 μm or more, the saturation magnetic field Hk hardly changes with a pattern width change of several μm, and an SV-GMR element with little variation can be obtained. As an example, the saturation magnetic field Hk is about half that of a conventional SV-GMR element having a pattern width of 9 μm, and the sensitivity is improved about twice when the non-saturation region of the SV-GMR element is used.

４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４は感磁パターンとなる磁気抵抗効果膜パターンを有する感磁面を持ち、それらの感磁面は図１の軟磁性体歯車１の外周面に接する平面に平行な同一平面内にあることが望ましく、対をなすＳＶ−ＧＭＲ素子Ｒ１，Ｒ２のうちＲ１はピン層の磁化方向が歯車回転方向の略逆方向、Ｒ２は略順方向である。同様に、もう１組の対をなすＳＶ−ＧＭＲ素子Ｒ３，Ｒ４のうちＲ３はピン層の磁化方向が歯車回転方向の略逆方向、Ｒ４は略順方向である。   The four SV-GMR elements R1, R2, R3, and R4 have a magnetosensitive surface having a magnetoresistive film pattern serving as a magnetosensitive pattern, and these magnetosensitive surfaces are the outer peripheral surface of the soft magnetic gear 1 of FIG. Of the pair of SV-GMR elements R1 and R2, R1 is the magnetization direction of the pinned layer is substantially opposite to the gear rotation direction, and R2 is substantially forward direction. . Similarly, among the other pair of SV-GMR elements R3 and R4, R3 has a magnetization direction of the pinned layer substantially opposite to the gear rotation direction, and R4 has a substantially forward direction.

図１（Ａ）の前記バイアス磁石５は、例えば軟磁性体歯車１の外周面に対向する面にＮ極、反対面にＳ極を有する永久磁石であり、Ｎ極面と軟磁性体歯車１間に４個のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４が位置する関係である。また、直線的に配列された各ＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４に略均等の磁界を印加できるように、４個のＳＶ−ＧＭＲ素子の配置幅Ｗ１より大きい十分な横幅を有することが望ましい。同様に、歯車１の厚みＷ２もＷ１以上であることが望ましい。   The bias magnet 5 in FIG. 1A is a permanent magnet having, for example, an N pole on the surface facing the outer peripheral surface of the soft magnetic gear 1 and an S pole on the opposite surface, and the N pole surface and the soft magnetic gear 1. In this relationship, four SV-GMR elements R1, R2, R3, and R4 are positioned between them. Also, it has a sufficient lateral width larger than the arrangement width W1 of the four SV-GMR elements so that a substantially uniform magnetic field can be applied to each of the linearly arranged SV-GMR elements R1, R2, R3, R4. Is desirable. Similarly, the thickness W2 of the gear 1 is desirably equal to or greater than W1.

図１（Ｂ）のように、ＳＶ−ＧＭＲ素子Ｒ１，Ｒ２の対と、もう一つのＳＶ−ＧＭＲ素子Ｒ３，Ｒ４の対とでホイートストンブリッジ回路を構成しており、このホイートストンブリッジ回路には一定の供給電圧Ｖinが供給されるようになっている。検出出力ＶoutはＲ１，Ｒ２の接続点とＲ３，Ｒ４の接続点間の電位差として得られる。   As shown in FIG. 1B, a pair of SV-GMR elements R1 and R2 and another pair of SV-GMR elements R3 and R4 constitute a Wheatstone bridge circuit. The supply voltage Vin is supplied. The detection output Vout is obtained as a potential difference between the connection points of R1 and R2 and the connection points of R3 and R4.

従って、図１（Ａ）のような配置で検知対象の軟磁性体歯車１の凸部２がＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４の感磁面に接近してきた時、各ＳＶ−ＧＭＲ素子の感磁面位置における磁束ベクトルの歯車回転接線方向成分は凸部２が接近してくる方向を向く。図７のように、ＳＶ−ＧＭＲ素子の磁気特性は、外部磁界の方向とピン層磁化方向とが順平行で抵抗変化率（ΔＲ／Ｒ）はマイナス、外部磁界の方向とピン層磁化方向とが反平行で抵抗変化率（ΔＲ／Ｒ）はプラスであるから、磁束ベクトル成分が凸部接近方向に向いた時、２対のＳＶ−ＧＭＲ素子（Ｒ１とＲ２の対、及びＲ３とＲ４の対）の一方のＳＶ−ＧＭＲ素子Ｒ１，Ｒ３では抵抗値が小となり（ピン層磁化方向と磁束ベクトル方向の歯車接線方向成分が順平行の時）、他方のＳＶ−ＧＭＲ素子Ｒ２，Ｒ４では抵抗値が大となる（ピン層磁化方向と磁束ベクトル方向の歯車接線方向成分が反平行の時）。   Therefore, when the convex portion 2 of the soft magnetic gear 1 to be detected approaches the magnetic sensitive surface of the SV-GMR elements R1, R2, R3, R4 in the arrangement as shown in FIG. 1A, each SV-GMR The gear rotation tangential component of the magnetic flux vector at the position of the magnetosensitive surface of the element faces the direction in which the convex portion 2 approaches. As shown in FIG. 7, the magnetic characteristics of the SV-GMR element are such that the direction of the external magnetic field and the pinned layer magnetization direction are in parallel, the resistance change rate (ΔR / R) is negative, the direction of the external magnetic field and the pinned layer magnetization direction. Are antiparallel and the rate of change in resistance (ΔR / R) is positive. Therefore, when the magnetic flux vector component is directed in the convex approaching direction, two pairs of SV-GMR elements (the pair of R1 and R2, and the pair of R3 and R4) In one SV-GMR element R1, R3, the resistance value is small (when the pin layer magnetization direction and the gear tangential direction component of the magnetic flux vector direction are forward parallel), and in the other SV-GMR element R2, R4, the resistance value is small. The value becomes large (when the pin layer magnetization direction and the magnetic flux vector direction are anti-parallel to the gear tangential component).

また、凸部２がＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４の感磁面から遠ざかる時、ＳＶ−ＧＭＲ素子の感磁面位置における磁束ベクトルの歯車回転接線方向成分は凸部２が遠ざかる方向を向く。磁束ベクトル成分が凸部の遠ざかる方向に向いた時、一方のＳＶ−ＧＭＲ素子Ｒ１，Ｒ３では抵抗値が大となり（ピン層磁化方向と磁束ベクトル方向の歯車接線方向成分が反平行の時）、他方のＳＶ−ＧＭＲ素子Ｒ２，Ｒ４では抵抗値が小となる（ピン層磁化方向と磁束ベクトル方向の歯車接線方向成分が順平行の時）。   Further, when the convex part 2 moves away from the magnetic sensitive surfaces of the SV-GMR elements R1, R2, R3, R4, the gear rotation tangential direction component of the magnetic flux vector at the magnetic sensitive surface position of the SV-GMR element is the direction in which the convex part 2 moves away. Facing. When the magnetic flux vector component is directed away from the convex portion, the resistance value is large in one of the SV-GMR elements R1 and R3 (when the pin layer magnetization direction and the gear tangential component of the magnetic flux vector direction are antiparallel), In the other SV-GMR elements R2 and R4, the resistance value is small (when the pinned layer magnetization direction and the gear tangential direction component of the magnetic flux vector direction are forward parallel).

このように、軟磁性体歯車１の凸部２が接近してくる時もしくは遠ざかる時、２対のＳＶ−ＧＭＲ素子の各々の対では、一方の抵抗値が最小、他方が最大となり、図１（Ｂ）のホイートストンブリッジ回路を組むことにより、１つのＳＶ−ＧＭＲ素子の４倍の検出出力Ｖoutを得ることが可能になる。検出出力Ｖoutは軟磁性体歯車１の凸部２が通過する毎に変化することから軟磁性体歯車１の回転検出が可能である。   As described above, when the convex portion 2 of the soft magnetic gear 1 approaches or moves away from each other, in each pair of the two pairs of SV-GMR elements, one resistance value is minimum and the other is maximum. By assembling the Wheatstone bridge circuit of (B), it becomes possible to obtain a detection output Vout that is four times that of one SV-GMR element. Since the detection output Vout changes every time the convex portion 2 of the soft magnetic gear 1 passes, the rotation of the soft magnetic gear 1 can be detected.

この実施の形態１によれば、次の通りの効果を得ることができる。   According to the first embodiment, the following effects can be obtained.

(1) ＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４の磁気抵抗効果膜パターン１２のピン層磁化方向の幅を２０μｍ以上としたことで、各ＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４の飽和磁界Ｈｋのばらつきを小さくでき、ひいては、検出出力の安定化を図ることができる。つまり、製品毎の検出出力電圧のばらつきを低減できる。 (1) The saturation of each SV-GMR element R1, R2, R3, R4 by setting the width of the magnetoresistive effect film pattern 12 of the SV-GMR elements R1, R2, R3, R4 to 20 μm or more. Variations in the magnetic field Hk can be reduced, and as a result, detection output can be stabilized. That is, the variation in the detection output voltage for each product can be reduced.

(2) 磁気抵抗効果膜パターン１２のピン層磁化方向の幅が２０μｍ以上であると、飽和磁界Ｈｋは低い値で安定し、高い感度を安定して得ることができる。１例として、従来のパターン幅９μｍのＳＶ−ＧＭＲ素子と比較して飽和磁界Ｈｋは約半分となり、感度を約２倍に向上させることができる。 (2) When the width of the magnetoresistive effect film pattern 12 in the pinned layer magnetization direction is 20 μm or more, the saturation magnetic field Hk is stable at a low value, and high sensitivity can be obtained stably. As an example, the saturation magnetic field Hk is about half that of a conventional SV-GMR element having a pattern width of 9 μm, and the sensitivity can be improved about twice.

(3) 磁気抵抗効果膜パターン１２のピン層磁化方向の幅が２０μｍ以上であるＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４を用いることで、軟磁性体歯車１とＳＶ−ＧＭＲ素子Ｒ１，Ｒ２，Ｒ３，Ｒ４間のギャップを適切値に維持したときでも、バイアス磁石５の大型化や材質変更は必要なく、小型で高感度の移動体検出装置を実現できる。 (3) By using the SV-GMR elements R1, R2, R3, R4 having a magnetoresistive effect film pattern 12 with a width in the pinned layer magnetization direction of 20 μm or more, the soft magnetic gear 1 and the SV-GMR elements R1, R2 Even when the gaps between R3, R3 and R4 are maintained at an appropriate value, it is not necessary to increase the size of the bias magnet 5 or change the material, and a small and highly sensitive moving body detection apparatus can be realized.

図４（Ａ），（Ｂ）は本発明の実施の形態２であって、磁性粉付着媒体又は磁性膜付着媒体を検出するのに適した移動体検出装置を示す。この場合、移動体検出装置は、図４（Ａ）に示すように、バイアス磁界印加用のバイアス磁石５Ａと一対のＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａとを備えている。ＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａは、バイアス磁石５Ａの磁極面（図では上面のＮ極面）に対向する位置（図４では磁極面の上側の位置）に、検出対象である検出媒体（磁性粉付着媒体又は磁性膜付着媒体）２１の移動方向（図４では水平方向）に対して略垂直（図４では奥行き方向）に並んで配置されている。一対のＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａのピン層磁化方向は、検出媒体２１の移動方向に対して略平行でかつ互いに逆向き（図４では水平方向右向き及び左向き）である。また、磁石５Ａは検出媒体１の移動方向に略垂直にＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａを磁気バイアスするものであり、つまりＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａの感磁面に対して略垂直な一定のバイアス磁界を印加している。   4 (A) and 4 (B) show a moving body detection apparatus suitable for detecting a magnetic powder adhering medium or a magnetic film adhering medium according to Embodiment 2 of the present invention. In this case, as shown in FIG. 4A, the moving body detection apparatus includes a bias magnet 5A for applying a bias magnetic field and a pair of SV-GMR elements R1A and R2A. The SV-GMR elements R1A and R2A are provided with a detection medium (magnetic powder) at a position (position above the magnetic pole face in FIG. 4) facing the magnetic pole face (upper N pole face in the figure) of the bias magnet 5A. The adhering medium or the magnetic film adhering medium) 21 is arranged side by side in a direction substantially perpendicular (depth direction in FIG. 4) to the moving direction (horizontal direction in FIG. 4). The pinned layer magnetization directions of the pair of SV-GMR elements R1A and R2A are substantially parallel to the moving direction of the detection medium 21 and opposite to each other (horizontal rightward and leftward in FIG. 4). The magnet 5A magnetically biases the SV-GMR elements R1A and R2A substantially perpendicular to the moving direction of the detection medium 1. That is, the magnet 5A is a constant perpendicular to the magnetosensitive surface of the SV-GMR elements R1A and R2A. A bias magnetic field is applied.

この実施の形態２の場合も、図４で使用する２個のＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａにおいて、その磁気抵抗効果膜パターンのピン層磁化方向の幅を２０μｍ以上に設定している。   Also in the second embodiment, in the two SV-GMR elements R1A and R2A used in FIG. 4, the width of the magnetoresistive effect film pattern in the pinned layer magnetization direction is set to 20 μm or more.

図４（Ｂ）のように、一対のＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａは、直列に接続されており、この直列接続の一方の側は直流定圧電源Ｖccに、他方の側はグランドラインに、それぞれ接続されている。そして、一対のＳＶ−ＧＭＲ素子Ｒ１，Ｒ２同士の直列接続部２５から検出出力信号Ｖoutを取り出す構成である。   As shown in FIG. 4B, the pair of SV-GMR elements R1A and R2A are connected in series. One side of the series connection is connected to the DC constant pressure power source Vcc, and the other side is connected to the ground line. It is connected. And it is the structure which takes out detection output signal Vout from the serial connection part 25 of a pair of SV-GMR element R1, R2.

検出媒体２１は、紙、プラスチックのフイルムやカード等に磁気インク等で磁性粉を付着させて磁性層パターン２２を形成した磁性粉付着媒体又は磁性膜付着媒体（例えば紙幣やカード）である。前記磁石５Ａ及び一対のＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａは、この検出媒体２１の移動経路に沿って配置され、検出媒体２１は図示しない移動手段によりＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａに近接対向した状態で図４（Ａ）の矢印方向（水平方向右向き）に走行可能となっている。   The detection medium 21 is a magnetic powder adhering medium or a magnetic film adhering medium (for example, a bill or a card) in which a magnetic layer pattern 22 is formed by adhering magnetic powder to a paper, plastic film, card or the like with magnetic ink or the like. The magnet 5A and the pair of SV-GMR elements R1A, R2A are arranged along the movement path of the detection medium 21, and the detection medium 21 is in close proximity to the SV-GMR elements R1A, R2A by a moving means (not shown). The vehicle can travel in the arrow direction (horizontal direction rightward) in FIG.

磁性層パターン２２の検出動作は以下の通りである。図４（Ａ）の１本の磁性層パターン２２がＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａの真上の手前側（左側）に近接すると、バイアス磁石５Ａによるバイアス磁界は磁性層パターン２２の影響で左上向きとなり、ＳＶ−ＧＭＲ素子Ｒ１Ａのピン層磁化方向に一致する磁界成分が発生し、ＳＶ−ＧＭＲ素子Ｒ１Ａは低抵抗、ＳＶ−ＧＭＲ素子Ｒ２Ａは高抵抗となり、図４（Ｂ）の検出出力信号Ｖoutの出力波形において前側の正のピーク電圧が得られる。そして、図４（Ａ）の１本の磁性層パターン２２がＳＶ−ＧＭＲ素子Ｒ１Ａ，Ｒ２Ａの真上を通過して右側に位置すると、バイアス磁石５Ａによるバイアス磁界は磁性層パターン２の影響で右上向きとなり、ＳＶ−ＧＭＲ素子Ｒ２Ａのピン層磁化方向に一致する磁界成分が発生し、ＳＶ−ＧＭＲ素子Ｒ１Ａは高抵抗、ＳＶ−ＧＭＲ素子Ｒ２Ａは低抵抗となり、図１（Ｂ）の検出出力信号Ｖoutの出力波形において後側の負のピーク電圧が得られる。   The detection operation of the magnetic layer pattern 22 is as follows. When one magnetic layer pattern 22 in FIG. 4A is close to the front side (left side) immediately above the SV-GMR elements R1A and R2A, the bias magnetic field by the bias magnet 5A is directed to the upper left due to the influence of the magnetic layer pattern 22 Thus, a magnetic field component matching the pinned layer magnetization direction of the SV-GMR element R1A is generated, the SV-GMR element R1A has a low resistance, and the SV-GMR element R2A has a high resistance, and the detection output signal Vout in FIG. A positive peak voltage on the front side is obtained in the output waveform. When one magnetic layer pattern 22 shown in FIG. 4A passes right above the SV-GMR elements R1A and R2A and is positioned on the right side, the bias magnetic field by the bias magnet 5A is affected by the magnetic layer pattern 2 to the right. A magnetic field component that coincides with the pinned layer magnetization direction of the SV-GMR element R2A is generated, the SV-GMR element R1A has a high resistance, and the SV-GMR element R2A has a low resistance, and the detection output signal of FIG. A negative peak voltage on the rear side is obtained in the output waveform of Vout.

この実施の形態２によっても、実施の形態１と同様に検出出力の安定した高感度の磁性粉付着媒体又は磁性膜付着媒体を対象とした移動体検出装置を実現できる。   Also according to the second embodiment, as in the first embodiment, it is possible to realize a moving object detection device targeting a highly sensitive magnetic powder adhering medium or magnetic film adhering medium having a stable detection output.

図５は本発明の各実施の形態で使用できるＳＶ−ＧＭＲ素子の変形例である。図５（Ａ）は基板１０に形成されたＡｕ電極パッド１１の延長リード部１１ａ間に磁気抵抗効果膜の直線状パターン１２が１本のみ形成、接続されている場合である。図５（Ｂ）は、対をなすＡｕ電極パッド１１間にそれぞれ延長リード部１１ａを介して磁気抵抗効果膜の直線状パターン１２が複数本形成され、複数本のパターン１２が対をなすＡｕ電極パッド１１間に電気的に並列に接続されている。図５（Ｃ）はＡｕ電極パッド１１の延長リード部１１ａ間に複数の磁気抵抗効果膜の直線状パターン１２をＡｕ接続リード部１３で相互に直列に接続したシングルミアンダパターン１４が形成されている。   FIG. 5 shows a modification of the SV-GMR element that can be used in each embodiment of the present invention. FIG. 5A shows a case where only one linear pattern 12 of the magnetoresistive effect film is formed and connected between the extended lead portions 11 a of the Au electrode pad 11 formed on the substrate 10. In FIG. 5B, a plurality of linear patterns 12 of the magnetoresistive effect film are formed between the paired Au electrode pads 11 via the extended lead portions 11a, respectively, and the plurality of patterns 12 form a pair of Au electrodes. The pads 11 are electrically connected in parallel. In FIG. 5C, a single meander pattern 14 in which a plurality of linear patterns 12 of magnetoresistive effect films are connected in series with each other by Au connection lead portions 13 is formed between the extended lead portions 11 a of the Au electrode pad 11. .

図５（Ａ）の磁気抵抗効果膜の直線状パターン１２が１本のＳＶ−ＧＭＲ素子の抵抗値をＲΩとしたとき、同図（Ｂ）の場合は磁気抵抗効果膜の直線状パターン１２が４本並列であるため、抵抗値はＲ／４Ωとなり、同図（Ｃ）の場合は磁気抵抗効果膜の直線状パターン１２が３本直列であるため、抵抗値は３ＲΩとなる。   When the resistance value of one SV-GMR element is RΩ in the linear pattern 12 of the magnetoresistive film in FIG. 5A, in the case of FIG. 5B, the linear pattern 12 of the magnetoresistive film is Since the four lines are in parallel, the resistance value is R / 4Ω, and in the case of FIG. 3C, the three linear patterns 12 of the magnetoresistive film are in series, so the resistance value is 3RΩ.

通常、ＳＶ−ＧＭＲ素子は、増幅回路と組み合わせて使用される。その際、回路が比較的容易になることから、複数のＳＶ−ＧＭＲ素子をフルブリッジ回路やハーフブリッジ回路として接続し、一定電圧を印加する構成が用いられる。この場合、ＳＶ−ＧＭＲ素子の磁気抵抗効果膜パターン幅のみを変更すると、ＳＶ−ＧＭＲ素子の抵抗値が大きく変化し、増幅回路との接続に相応しい抵抗値から外れ、増幅回路とのマッチングの低下や、消費電流が大きくなる問題が考えられる。しかし、この点に関しては、図５に示したように、所望の飽和磁界Ｈｋの磁気抵抗効果膜パターンを並列、直列、あるいは両方の組み合わせで接続することにより自在に調整できるので問題にならない。   Usually, the SV-GMR element is used in combination with an amplifier circuit. At that time, since the circuit becomes relatively easy, a configuration in which a plurality of SV-GMR elements are connected as a full bridge circuit or a half bridge circuit and a constant voltage is applied is used. In this case, if only the magnetoresistive effect film pattern width of the SV-GMR element is changed, the resistance value of the SV-GMR element greatly changes, deviates from the resistance value suitable for connection with the amplifier circuit, and the matching with the amplifier circuit is lowered. In addition, there may be a problem that current consumption increases. However, this point is not a problem because it can be freely adjusted by connecting the magnetoresistive effect film pattern of the desired saturation magnetic field Hk in parallel, in series, or a combination of both as shown in FIG.

図６は本発明の各実施の形態で使用できるＳＶ−ＧＭＲ素子の他の変形例である。図６（Ａ）は、基板１０上のＡｕ電極パッド１１の延長リード部１１ａ間に複数の磁気抵抗効果膜の直線状パターン１２をＡｕ接続リード部１３で相互に直列に接続したシングルミアンダパターン１４を示し、同図（Ｂ）は、２つのミアンダパターンを相互に入り組むように形成したダブルミアンダパターン１５を示し、各ミアンダパターンは２対設けられたＡｕ電極パッド１１間にそれぞれ接続されている（図６（Ａ）と同一又は相当部分には同一符号を付した）。図６（Ｂ）のダブルミアンダパターンの場合、同一基板上に２個（一対）のＳＶ−ＧＭＲ素子が構成されることになる。なお、同一基板上に複数対のＳＶ−ＧＭＲ素子をそれぞれダブルミアンダパターンで構成することもできる。   FIG. 6 shows another modification of the SV-GMR element that can be used in each embodiment of the present invention. 6A shows a single meander pattern 14 in which a plurality of linear patterns 12 of a magnetoresistive effect film are connected in series with each other by an Au connection lead portion 13 between extended lead portions 11 a of an Au electrode pad 11 on a substrate 10. FIG. 4B shows a double meander pattern 15 formed so that two meander patterns are interleaved with each other, and each meander pattern is connected between two pairs of Au electrode pads 11 ( The same or corresponding parts as those in FIG. In the case of the double meander pattern shown in FIG. 6B, two (a pair) SV-GMR elements are formed on the same substrate. In addition, a plurality of pairs of SV-GMR elements can be respectively configured with a double meander pattern on the same substrate.

図６（Ｂ）のように、磁気抵抗効果膜パターン１２の幅が２０μｍのＳＶ−ＧＭＲ素子を用いつつ、複数素子分の磁気抵抗効果膜パターンを含むダブルミアンダパターンとすることで、ＳＶ−ＧＭＲ素子を集中配置でき、基板１０を切り出すウエハの無駄を減らし、かつＳＶ−ＧＭＲ素子を用いる移動体検出装置の小型化も可能となる。   As shown in FIG. 6B, by using a SV-GMR element having a magnetoresistive effect film pattern 12 having a width of 20 μm, a double meander pattern including a magnetoresistive effect film pattern for a plurality of elements is obtained. The elements can be centrally arranged, the waste of the wafer for cutting the substrate 10 can be reduced, and the moving body detection apparatus using the SV-GMR element can be downsized.

なお、各実施の形態においてバイアス磁界発生手段として永久磁石を用いたが、動作原理上、電磁石を用いてもよい。   In each embodiment, a permanent magnet is used as the bias magnetic field generating means. However, an electromagnet may be used in terms of the operating principle.

以上本発明の実施の形態について説明してきたが、本発明はこれに限定されることなく請求項の記載の範囲内において各種の変形、変更が可能なことは当業者には自明であろう。   Although the embodiments of the present invention have been described above, it will be obvious to those skilled in the art that the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the claims.

本発明に係る移動体検出装置の実施の形態１であって、（Ａ）は移動体検出装置の構成を示す模式的斜視図、（Ｂ）は回路図である。BRIEF DESCRIPTION OF THE DRAWINGS It is Embodiment 1 of the mobile body detection apparatus which concerns on this invention, Comprising: (A) is a typical perspective view which shows the structure of a mobile body detection apparatus, (B) is a circuit diagram. 本発明の実施の形態で用いるＳＶ−ＧＭＲ素子であって、（Ａ）は磁気抵抗効果膜パターン長さが１２０μｍ、（Ｂ）は磁気抵抗効果膜パターン長さが６０μｍ、（Ｃ）は磁気抵抗効果膜パターン長さが３０μｍの場合の平面図である。FIG. 4 shows an SV-GMR element used in an embodiment of the present invention, wherein (A) shows a magnetoresistive film pattern length of 120 μm, (B) shows a magnetoresistive film pattern length of 60 μm, and (C) shows a magnetoresistive film. It is a top view in case an effect film | membrane pattern length is 30 micrometers. 磁気抵抗効果膜パターンのピン層磁化方向の幅と飽和磁界Ｈｋの関係を示すグラフである。It is a graph which shows the relationship between the width | variety of the pin layer magnetization direction of a magnetoresistive effect film pattern, and the saturation magnetic field Hk. 本発明に係る移動体検出装置の実施の形態２であって、（Ａ）は移動体検出装置の構成を示す模式的斜視図、（Ｂ）は回路図である。It is Embodiment 2 of the mobile body detection apparatus which concerns on this invention, Comprising: (A) is a typical perspective view which shows the structure of a mobile body detection apparatus, (B) is a circuit diagram. 本発明の各実施の形態で使用可能なＳＶ−ＧＭＲ素子の変形例であって、（Ａ）は１本の磁気抵抗効果膜パターン、（Ｂ）は磁気抵抗効果膜パターンの並列接続、（Ｃ）は磁気抵抗効果膜パターンの直列接続を有する場合をそれぞれ示す平面図である。FIG. 7 is a modified example of the SV-GMR element that can be used in each embodiment of the present invention, in which (A) is one magnetoresistive film pattern, (B) is a parallel connection of magnetoresistive film patterns, (C ) Is a plan view showing a case where the magnetoresistive film patterns are connected in series. 本発明の各実施の形態で使用可能なＳＶ−ＧＭＲ素子の他の変形例であって、（Ａ）は磁気抵抗効果膜パターンを含むシングルミアンダパターン、（Ｂ）はダブルミアンダパターンを有する場合をそれぞれ示す平面図である。It is another modification of the SV-GMR element that can be used in each embodiment of the present invention, in which (A) shows a single meander pattern including a magnetoresistive effect film pattern, and (B) shows a case having a double meander pattern. It is a top view shown, respectively. ＳＶ−ＧＭＲ素子の膜構成及び磁気特性を示す説明図である。It is explanatory drawing which shows the film | membrane structure and magnetic characteristic of a SV-GMR element. ＳＶ−ＧＭＲ素子の飽和磁界Ｈｋの変化により、非飽和領域の磁界−抵抗変化率の関係を示す直線の傾きが変化し、入力信号に対する出力信号がその傾き変化で変動することを示す説明図である。FIG. 4 is an explanatory diagram showing that the slope of a straight line indicating the relationship between the magnetic field and resistance change rate in the non-saturation region changes due to the change in the saturation magnetic field Hk of the SV-GMR element, and the output signal with respect to the input signal varies with the change in the slope. is there.

符号の説明Explanation of symbols

１ 軟磁性体歯車
２ 凸部
５，５Ａ バイアス磁石
１０ 基板
１１ 電極パッド
１１ａ 延長リード部
１２ 直線状パターン
１３ 接続リード部
１４ シングルミアンダパターン
１５ ダブルミアンダパターン
２１ 検出媒体
２２ 磁性層パターン
Ｒ１，Ｒ２，Ｒ１Ａ，Ｒ２Ａ，Ｒ３，Ｒ４ ＳＶ−ＧＭＲ素子 DESCRIPTION OF SYMBOLS 1 Soft magnetic gear 2 Convex part 5,5A Bias magnet 10 Board | substrate 11 Electrode pad 11a Extension lead part 12 Linear pattern 13 Connection lead part 14 Single meander pattern 15 Double meander pattern 21 Detection medium 22 Magnetic layer pattern R1, R2, R1A , R2A, R3, R4 SV-GMR elements

Claims (5)

磁性材移動体と、磁界発生手段と、少なくとも１つのスピンバルブ型巨大磁気抵抗素子とを有する移動体検出装置であって、
前記磁界発生手段は、前記スピンバルブ型巨大磁気抵抗素子の感磁面位置において前記感磁面と略垂直となるバイアス磁界を発生し、
前記スピンバルブ型巨大磁気抵抗素子が１対又は複数対あり、対をなす前記スピンバルブ型巨大磁気抵抗素子のピン層磁化方向が互いに前記磁性材移動体の移動方向に対し、略順方向と略逆方向を向くように配置され、
前記磁性材移動体の移動に伴って、前記スピンバルブ型巨大磁気抵抗素子の感磁面位置における前記バイアス磁界が、前記ピン層磁化方向と順平行又は反平行な成分を有する状態と、前記感磁面と略垂直な状態との間で変化し、
前記スピンバルブ型巨大磁気抵抗素子が有する磁気抵抗効果膜パターンのピン層磁化方向の幅を２０μｍ以上としたことを特徴とする移動体検出装置。 A moving body detection apparatus having a magnetic material moving body, a magnetic field generating means, and at least one spin valve type giant magnetoresistive element,
The magnetic field generating means generates a bias magnetic field that is substantially perpendicular to the magnetosensitive surface at the magnetosensitive surface position of the spin valve type giant magnetoresistive element,
The spin valve giant magnetoresistive element has one or more pairs, and the pin layer magnetization directions of the paired spin valve giant magnetoresistive elements are substantially forward and substantially relative to the moving direction of the magnetic material moving body. Placed in the opposite direction,
As the magnetic material moving body moves, the bias magnetic field at the position of the magnetosensitive surface of the spin-valve giant magnetoresistive element has a component that is forward-parallel or anti-parallel to the pinned layer magnetization direction; Changes between the magnetic surface and the almost perpendicular state,
A moving body detection apparatus, wherein the magnetoresistive effect film pattern of the spin valve giant magnetoresistive element has a pinned layer magnetization direction width of 20 μm or more. 前記磁性材移動体が少なくとも１つの凸部又は凹部を有している請求項１記載の移動体検出装置。 The moving body detection apparatus according to claim 1, wherein the magnetic material moving body has at least one convex portion or concave portion. 前記磁性材移動体が磁性粉付着媒体又は磁性膜付着媒体である請求項１記載の移動体検出装置。 The moving body detection apparatus according to claim 1, wherein the magnetic material moving body is a magnetic powder adhering medium or a magnetic film adhering medium. 前記スピンバルブ型巨大磁気抵抗素子が磁気抵抗効果膜パターンの直列接続、並列接続の一方又は両方を有するものである請求項１から３のいずれか記載の移動体検出装置。 The mobile object detection device according to any one of claims 1 to 3, wherein the spin valve type giant magnetoresistive element has one or both of series connection and parallel connection of magnetoresistive effect film patterns. 前記スピンバルブ型巨大磁気抵抗素子が同一基板上に一対又は複数対形成され、対をなすスピンバルブ型巨大磁気抵抗素子が磁気抵抗効果膜パターンを含むダブルミアンダパターンで構成されている請求項１から３のいずれか記載の移動体検出装置。 The spin-valve giant magnetoresistive elements are one or more pairs formed on the same substrate, from claim 1 spin-valve giant magnetoresistive element in a pair is composed of a double meander pattern comprising magnetoresistive film pattern 4. The moving body detection device according to any one of 3 .
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