JP5243725B2 - Magnetic detection sensor - Google Patents
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Description
本発明は、磁性を有する被検出媒体の検出等に用いられる磁性体検出センサに関するものである。 The present invention relates to a magnetic substance detection sensor used for detecting a medium to be detected having magnetism.
媒体に含まれる磁気インクや磁性粒子等の検出に用いられるセンサとしては、従来から磁気ヘッドや磁気抵抗素子を用いたものが知られている。これらのセンサは、媒体の磁気分布の勾配を検出する構成となっているため、パターン認識等の磁気の有無を検出する用途に有効である。 Conventionally, sensors using a magnetic head or a magnetoresistive element are known as sensors used for detecting magnetic ink, magnetic particles, and the like contained in a medium. Since these sensors are configured to detect the gradient of the magnetic distribution of the medium, they are effective for use in detecting the presence or absence of magnetism such as pattern recognition.
これに対して、磁気インピーダンス素子等の高感度な磁界検出素子を用いて、磁気の有無だけでなく、媒体の磁気分布を量的に検出可能としたものが提案されている（特許文献１参照）。このセンサは、図３５、図３６に示すように検出に先行する着磁手段を持ち、媒体の着磁部の中心軸Ｌから対称に発生する磁界を、磁界検出方向に沿って並べられた２つの磁気インピーダンス素子で検出するものである。 On the other hand, using a highly sensitive magnetic field detection element such as a magnetic impedance element, it has been proposed to be able to quantitatively detect not only the presence or absence of magnetism but also the magnetic distribution of the medium (see Patent Document 1). ). As shown in FIGS. 35 and 36, this sensor has magnetizing means preceding detection, and magnetic fields generated symmetrically from the central axis L of the magnetized portion of the medium are arranged along the magnetic field detection direction. It is detected by two magnetic impedance elements.
２つの素子には同方向のバイアス磁界が印加され、それらを差動検出することによりノイズ磁界を除去し、媒体からの磁界を精度良く検出する。このセンサは、従来に無い磁気情報を提供することができ、特に、紙幣の鑑別等のセキュリティ用途で有効性を発揮する。しかし、着磁後の残留磁気量を検出する構成であるため、軟磁性材等残留磁気量の少ない媒体の検出には不利な点があった。 A bias magnetic field in the same direction is applied to the two elements, and by detecting them differentially, the noise magnetic field is removed and the magnetic field from the medium is accurately detected. This sensor can provide unprecedented magnetic information, and is particularly effective for security applications such as bill discrimination. However, since the configuration is such that the amount of residual magnetism after magnetization is detected, there is a disadvantage in detecting a medium with a small amount of residual magnetism, such as a soft magnetic material.
これに対して、軟磁性材であっても量的に検出可能としたものが提案されている（特許文献２参照）。このセンサは、磁石のＮＳ軸の中点を通る平面上に素子を配置して磁界検出方向に磁界が加わらないようにした構成で、高感度ではあるが使用できる磁界範囲が狭い磁界検出素子を、特性を低下させずに磁石の近傍で使用できる。 On the other hand, a soft magnetic material that can be quantitatively detected has been proposed (see Patent Document 2). This sensor has a configuration in which the element is arranged on a plane passing through the midpoint of the NS axis of the magnet so that no magnetic field is applied in the magnetic field detection direction. Can be used in the vicinity of the magnet without degrading the characteristics.
このため、軟磁性材であっても高精度に磁気量検出が可能であり、また、小型化も実現できる。このセンサで、磁気インピーダンス素子を用いる場合には、図３７に示すようにバイアス磁石９３等によって２つの素子９２１、９２２に同方向のバイアス磁界を印加する。それらを差動検出することで、ノイズ磁界を除去しながら媒体からの磁界を精度良く検出する。
磁界検出素子を磁石のＮＳ軸の中点を通る平面に配置する構成は、例えば、直交フラックスゲート素子のように、ゼロ磁界で感度を有してバイアス磁界を必要としない磁界検出素子には最適である。しかし、バイアス磁界を必要とする磁界検出素子の場合には、図３７のようなバイアス磁石９３バイアスコイル等が必要になり、サイズやコストの面で不利な点がある。 The configuration in which the magnetic field detection element is arranged on a plane passing through the midpoint of the NS axis of the magnet is optimal for a magnetic field detection element that has sensitivity at zero magnetic field and does not require a bias magnetic field, such as an orthogonal fluxgate element. It is. However, in the case of a magnetic field detection element that requires a bias magnetic field, a bias magnet 93 bias coil or the like as shown in FIG. 37 is required, which is disadvantageous in terms of size and cost.
また、変位センサやエンコーダにおいては、検出する磁気量の大きさが広範囲に渡るため、磁気インピーダンス素子等の高感度磁界検出素子では、所定の動作磁界範囲を超えると誤動作を起こすことがある。 In addition, since displacement sensors and encoders have a wide range of magnetic magnitudes to be detected, high-sensitivity magnetic field detection elements such as magneto-impedance elements may malfunction if they exceed a predetermined operating magnetic field range.
本発明の目的は、検出すべき磁性体の種類や形状に依らずに安定して動作し、高感度で、且つ小型化、省スペース化ができ、更には生産性が高い磁性体検出センサを提供することにある。 An object of the present invention is to provide a magnetic substance detection sensor that operates stably regardless of the type and shape of the magnetic substance to be detected, is highly sensitive, can be reduced in size and space, and has high productivity. It is to provide.
本発明に係る磁性体検出センサは、磁界を発生する磁石と前記磁界の変化を検出する磁性膜を有する磁界検出素子とを備え、磁性材料を含む被検出媒体を検出する磁性体検出センサにおいて、前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が近接する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、前記磁性膜は薄膜であって前記平面に沿った磁気異方性を有し且つ前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有し、前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置している、ことを特徴とする。
また、本発明に係る磁性体検出センサは、磁界を発生する磁石と前記磁界の変化を検出する磁性膜を有する磁界検出素子とを備え、磁性材料を含む被検出媒体を検出する磁性体検出センサにおいて、前記磁石のＮＳ方向を法線とし、前記磁石の該ＮＳ軸の中点よりも前記被検出媒体が近接する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置し、前記磁界検出素子は、前記磁石の前記被検出媒体が近接する磁極と反対側の磁極と同一平面上に配置されている、ことを特徴とする。
更に、本発明に係る磁性体検出センサは、磁界を発生する磁石と前記磁界の変化を検出する磁性膜を有する磁界検出素子とを備え、磁性材料を含む被検出媒体を検出する磁性体検出センサにおいて、前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が接近する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、前記磁性膜は薄膜であって前記平面に沿った磁気異方性を有し且つ前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有する、ことを特徴とする。
本発明に係る磁性体検出センサは、磁界を発生する磁石と前記磁界の変化を検出する磁性膜を有する磁界検出素子とを備え、磁性材料を含む被検出媒体を検出する磁性体検出センサにおいて、前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が接近する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、前記磁性膜は前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有し、前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置している、ことを特徴とする。
A magnetic substance detection sensor according to the present invention comprises a magnet that generates a magnetic field and a magnetic field detection element having a magnetic film that detects a change in the magnetic field, and detects a detected medium containing a magnetic material. The magnetic field detection element is disposed on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet, the NS direction of the magnet being a normal line, and the detected medium is closer to the NS of the NS axis of the magnet. The magnetic film is a thin film, has a magnetic anisotropy along the plane, and has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction, and the magnetic field detection element is applied by the magnet. that the bias magnetic field is located in a region where magnetization is saturated in the magnetic field detecting direction of the magnetic film of the magnetic field detecting element, characterized in that.
In addition, a magnetic substance detection sensor according to the present invention includes a magnet that generates a magnetic field and a magnetic field detection element having a magnetic film that detects a change in the magnetic field, and detects a detection medium containing a magnetic material. The magnetic field detecting element on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet closer to the medium to be detected than the midpoint of the NS axis of the magnet And the magnetic field detection element is located in a region where the magnetization of the magnetic film of the magnetic field detection element is saturated in the magnetic field detection direction, and the magnetic field detection element is The detection medium is arranged on the same plane as the magnetic pole on the opposite side to the adjacent magnetic pole.
Furthermore, a magnetic substance detection sensor according to the present invention includes a magnet for generating a magnetic field and a magnetic field detection element having a magnetic film for detecting a change in the magnetic field, and detects a detection medium containing a magnetic material. The magnetic field detection element is on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet closer to the detected medium than the midpoint of the NS axis of the magnet. The magnetic film is a thin film, has a magnetic anisotropy along the plane, and has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction.
A magnetic substance detection sensor according to the present invention comprises a magnet that generates a magnetic field and a magnetic field detection element having a magnetic film that detects a change in the magnetic field, and detects a detected medium containing a magnetic material. The magnetic field detection element is arranged on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet, the NS direction of the magnet being a normal line and the detected medium approaching the midpoint of the NS axis of the magnet. The magnetic film has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction, and the magnetic field detection element has a bias magnetic field applied by the magnet so that the magnetization of the magnetic film of the magnetic field detection element has a magnetic field detection direction. It is located in the area | region which saturates to.
また、前記磁界検出素子は、前記磁石の前記磁性体が近接する磁極と反対側の磁極と同一平面上に配置されているのが好ましい。 The magnetic field detection element is preferably arranged on the same plane as the magnetic pole on the side opposite to the magnetic pole close to the magnetic body of the magnet.
また、前記磁石と前記磁界検出素子は同一の基板上に搭載されているのが好ましい。 The magnet and the magnetic field detection element are preferably mounted on the same substrate.
また、前記磁界検出素子は磁気インピーダンス素子であるのが好ましい。 The magnetic field detecting element is preferably a magnetic impedance element.
また、前記磁界検出素子は少なくとも２つあり、前記平面上において前記法線と交差する前記平面上の一つの直線に対して線対称に配置されており、前記２つの磁界検出素子の出力の和に応じた信号を出力するのが好ましい。 Further, there are at least two magnetic field detection elements, which are arranged symmetrically with respect to one straight line on the plane intersecting the normal line on the plane, and the sum of outputs of the two magnetic field detection elements. It is preferable to output a signal according to the above.
また、磁性体検出センサが複数配列されていても良い。 A plurality of magnetic substance detection sensors may be arranged.
また、磁性体検出センサが、前記磁石を共通にして２つ配置されていても良い。 Two magnetic substance detection sensors may be arranged with the magnets in common.
また、所定の間隔で磁性体が配置された可動部材と、上記の磁性体検出装置を備え、前記２つの磁性体検出センサの出力の夫々を所定の閾値でパルス化する回路と、前記可動部材の移動に応じて出力される前記２つのパルス信号の位相差とパルス数によって、前記可動部材の移動量及び移動方向を検出する回路とを備えたことを特徴とする入力デバイスであっても良い。 A movable member having a magnetic body arranged at a predetermined interval; a circuit for pulsing each of the outputs of the two magnetic body detection sensors at a predetermined threshold; and the movable member. The input device may further include a circuit that detects a moving amount and a moving direction of the movable member based on a phase difference and a pulse number of the two pulse signals output according to the movement of the moving member. .
本発明によれば、誤動作がなく、動作が安定で、磁石と磁界検出素子を、例えば、プリント基板上に実装するだけで磁性体検出センサを構成でき、生産性がよく、低コスト化が可能となる。従って、検出できる磁気量範囲が広く、動作が安定で、且つ、小型で駆動回路も含めた省スペース化に対応でき、更には、生産性が高い磁性体検出センサを実現できる。また、本発明の磁性体検出センサを用いることにより、小型で高性能な磁性体検出装置を実現することができる。 According to the present invention, there is no malfunction, the operation is stable, and a magnetic substance detection sensor can be configured simply by mounting a magnet and a magnetic field detection element on, for example, a printed circuit board, resulting in high productivity and low cost. It becomes. Therefore, it is possible to realize a magnetic substance detection sensor that has a wide range of magnetic amount that can be detected, is stable in operation, is small in size, can be used in a space-saving manner including a drive circuit, and has high productivity. Further, by using the magnetic body detection sensor of the present invention, a small and high performance magnetic body detection device can be realized.
次に、発明を実施するための最良の形態について図面を用いて詳細に説明する。まず、本発明は、磁界を発生する磁石と磁界の変化を検出する磁界検出素子とを含む磁性体検出センサである。磁石のＮＳ軸を法線とし、磁石のＮＳ軸の中点よりも被検出媒体が近接する磁石の磁極と反対側の磁極側に位置する平面上に磁界検出素子は配置され、磁石により印加されるバイアス磁界が磁界検出素子の磁性膜の磁化が磁界検出方向に飽和した領域に配置されている。 Next, the best mode for carrying out the invention will be described in detail with reference to the drawings. First, the present invention is a magnetic substance detection sensor including a magnet that generates a magnetic field and a magnetic field detection element that detects a change in the magnetic field. The NS axis of the magnet and a normal line, the magnetic field detection element on a plane that is located on the pole side of the magnetic pole opposite to the magnets which the detection medium is closer than the midpoint of the NS axis of the magnet is disposed, and more applied to the magnet The bias magnetic field is arranged in a region where the magnetization of the magnetic film of the magnetic field detection element is saturated in the magnetic field detection direction .
また磁界検出素子は磁石の磁性体が近接する磁極と反対側の磁極と同一平面上に配置されている。磁石と磁界検出素子は同一の基板上に搭載されている。また、磁界検出素子は少なくとも２つあり、平面上において法線と交差する平面上の一つの直線に対して線対称に配置されており、２つの磁界検出素子の出力の和に応じた信号を出力する。 The magnetic field detecting element is disposed on the same plane as the magnetic pole on the side opposite to the magnetic pole close to the magnetic body of the magnet. The magnet and the magnetic field detection element are mounted on the same substrate. In addition, there are at least two magnetic field detection elements, which are arranged symmetrically with respect to one straight line on a plane that intersects the normal line on the plane, and a signal corresponding to the sum of the outputs of the two magnetic field detection elements. Output.
また、本発明の磁性体検出センサを複数配列することで磁性体検出ラインセンサを構成する。更に本発明の磁性体検出装置は磁性体検出センサ又は磁性体検出ラインセンサを用いて磁性体の検出を行う。 In addition, a magnetic body detection line sensor is configured by arranging a plurality of the magnetic body detection sensors of the present invention. Furthermore, the magnetic body detection device of the present invention detects a magnetic body using a magnetic body detection sensor or a magnetic body detection line sensor.
図１は本発明の基本構成を示す。図１（ａ）〜図１（ｃ）はそれぞれ本発明の実施形態を示すが、図１（ａ）〜図１（ｃ）は磁界検出素子１３の配置が異なっている。図１（ａ）では磁性体検出センサ１は磁石１２と磁界検出素子１３から成り、磁界検出素子１３は磁石１２のＮ極と同一平面上に配置されている。 FIG. 1 shows the basic configuration of the present invention. 1 (a) to 1 (c) show embodiments of the present invention, respectively, but FIG. 1 (a) to FIG. 1 (c) differ in the arrangement of the magnetic field detection elements 13. FIG. In FIG. 1A, the magnetic body detection sensor 1 includes a magnet 12 and a magnetic field detection element 13, and the magnetic field detection element 13 is disposed on the same plane as the N pole of the magnet 12.
磁界検出素子１３は非磁性基板２１上に形成された磁性膜１５と電極１７、１８から成り、磁性膜１５の長手方向が磁界検出方向になっている。磁性材料を含有する媒体２３は磁石１２のＳ極に近接し、その際の磁界変化を磁界検出素子１３で検出する。 The magnetic field detection element 13 includes a magnetic film 15 formed on a nonmagnetic substrate 21 and electrodes 17 and 18, and the longitudinal direction of the magnetic film 15 is a magnetic field detection direction. The medium 23 containing the magnetic material is close to the south pole of the magnet 12, and the magnetic field change at that time is detected by the magnetic field detection element 13.
図１（ｂ）では、磁界検出素子１３は非磁性基板２１の背面が磁石１２のＮ極と同一平面上に配置されている。その他の構成は図１（ａ）と同様である。磁界検出素子１３の位置は図１（ｃ）に示すように更に媒体２３から遠い位置にあっても良いが、実装の容易性の点で図１（ａ）又は図１（ｂ）の配置の方が好ましい。 In FIG. 1B, the magnetic field detection element 13 is arranged such that the back surface of the nonmagnetic substrate 21 is on the same plane as the N pole of the magnet 12. Other configurations are the same as those in FIG. The position of the magnetic field detection element 13 may be further away from the medium 23 as shown in FIG. 1C, but the arrangement of FIG. 1A or FIG. Is preferred.
磁界検出素子１３は磁気インピーダンス素子であるのが最良であるが、バイアス磁界の下で動作する磁界検出素子であれば特に制限は無く、ＧＭＲ等の磁界検出素子であっても良い。磁界検出素子１３は磁石１２のＮＳ方向に強い磁界を受けるが、その影響を抑えるために反磁界の大きい薄膜で形成するのが最良である。 The magnetic field detection element 13 is best a magnetic impedance element, but is not particularly limited as long as it is a magnetic field detection element that operates under a bias magnetic field, and may be a magnetic field detection element such as GMR. The magnetic field detecting element 13 receives a strong magnetic field in the NS direction of the magnet 12, but it is best to form the thin film with a large demagnetizing field in order to suppress the influence.
磁界検出素子１３を形成する非磁性基板２１には、ガラスやセラミック、シリコン基板等を用いることができるが、形成する磁性膜と熱膨張係数の近いものを選択するのが望ましい。図１では磁性膜１５は３本の磁性パターンを接続したつづら折れ状に形成されているが、これは一例であり、磁性膜パターンに特に制限は無い。電極１７、１８についても配置や形状に特に制限は無い。 As the nonmagnetic substrate 21 on which the magnetic field detection element 13 is formed, glass, ceramic, silicon substrate or the like can be used, but it is desirable to select a substrate having a thermal expansion coefficient close to that of the magnetic film to be formed. In FIG. 1, the magnetic film 15 is formed in a zigzag shape in which three magnetic patterns are connected. However, this is an example, and the magnetic film pattern is not particularly limited. The arrangement and shape of the electrodes 17 and 18 are not particularly limited.
図１（ａ）の構成はハンダ実装等に適した構成であり、図１（ｂ）はワイヤボンディングによる実装等に適した構成である。電極１７、１８には、それらに合わせてＣｕやＡｌ等の材料が選択される。図１（ｂ）の構成では非磁性基板２１の厚みを磁石１２のＮＳ軸の半分以下にする必要があるが、図１（ａ）ではＮＳ軸と同等の厚みまで可能である。磁性体検出センサ１の薄型化のために磁石１２のＮＳ軸を短くする場合には、基板２１の強度の点から図１（ａ）の構成の方が好ましい。 The configuration of FIG. 1A is a configuration suitable for solder mounting or the like, and FIG. 1B is a configuration suitable for mounting by wire bonding or the like. For the electrodes 17 and 18, a material such as Cu or Al is selected in accordance with them. In the configuration of FIG. 1B, the thickness of the non-magnetic substrate 21 needs to be less than half of the NS axis of the magnet 12, but in FIG. 1A, the thickness can be equal to the NS axis. When the NS axis of the magnet 12 is shortened in order to reduce the thickness of the magnetic substance detection sensor 1, the configuration shown in FIG.
次に、図２と図３を用いて本発明の検出原理を説明する。以下の説明は図１（ａ）の構成を例として説明するが、図１（ｂ）の構成でも全く同様である。図２（ａ）は図１（ａ）を上から見た図、図２（ｂ）は図１（ａ）を側面から見た図である。図２において、磁界検出素子１３は磁石１２のＮＳ軸に垂直なｘ方向が磁界検出方向であり、磁石１２からバイアス磁界Ｈｂを受ける。 Next, the detection principle of the present invention will be described with reference to FIGS. In the following description, the configuration of FIG. 1A will be described as an example, but the configuration of FIG. 2A is a view of FIG. 1A viewed from above, and FIG. 2B is a view of FIG. 1A viewed from the side. In FIG. 2, the magnetic field detection element 13 receives the bias magnetic field Hb from the magnet 12 in the x direction perpendicular to the NS axis of the magnet 12.
バイアス磁界Ｈｂは磁石１２のＮＳ軸に平行なｚ方向の位置に対して大きく変化するが、磁石１２と磁界検出素子１３を、例えば、同一基板上に実装する等すれば、容易に位置精度を得ることができる。また、磁石１２からは磁性膜の膜厚方向に大きな磁界Ｈｚを受けるが、反磁界が大きく磁界検出素子の特性に大きな影響はない。 The bias magnetic field Hb varies greatly with respect to the position of the magnet 12 in the z direction parallel to the NS axis. However, if the magnet 12 and the magnetic field detection element 13 are mounted on the same substrate, for example, the positional accuracy can be easily obtained. Can be obtained. The magnet 12 receives a large magnetic field Hz in the thickness direction of the magnetic film, but has a large demagnetizing field and does not significantly affect the characteristics of the magnetic field detecting element.
バイアス磁界Ｈｂの大きさは磁石１２のＮＳ間距離に依存し、また、ｘ方向の磁界検出素子１３の位置によって図２（ｄ）に示すように連続的に変化する。磁石の大きさと磁界検出素子の位置を適当に設定することにより、バイアス設定が必要な磁界検出素子を有効に用いることができる。 The magnitude of the bias magnetic field Hb depends on the NS distance of the magnet 12 and continuously changes depending on the position of the magnetic field detection element 13 in the x direction as shown in FIG. By appropriately setting the size of the magnet and the position of the magnetic field detection element, a magnetic field detection element that requires a bias setting can be used effectively.
ｘ方向の位置による設定が難しい場合には、図２（ｅ）に示すように磁石１２のＮＳ軸の動径方向と磁界検出素子１３の磁界検出方向に角度を持たせる配置によっても調整が可能である。媒体２３は磁石１２の磁界によって磁化され、それにより磁界検出素子１３は磁界Ｈｍを受ける。 If setting by the position in the x direction is difficult, adjustment is possible by arranging an angle between the radial direction of the NS axis of the magnet 12 and the magnetic field detection direction of the magnetic field detection element 13 as shown in FIG. It is. The medium 23 is magnetized by the magnetic field of the magnet 12, whereby the magnetic field detection element 13 receives the magnetic field Hm.
図２（ｃ）はｚ方向の位置によるバイアス磁界Ｈｂの分布であり、媒体２３の有無により実線から点線の分布へと変化する。ＮＳ軸の中央に対して、媒体２３に近い側ではバイアス磁界が減少する方向に、図２（ｂ）の配置のように媒体２３から遠い側ではバイアス磁界が増加する方向に磁界が変化する。 FIG. 2C shows the distribution of the bias magnetic field Hb depending on the position in the z direction, and changes from a solid line to a dotted line distribution depending on the presence or absence of the medium 23. The magnetic field changes in the direction in which the bias magnetic field decreases on the side closer to the medium 23 with respect to the center of the NS axis, and in the direction in which the bias magnetic field increases on the side far from the medium 23 as shown in FIG.
図３は素子特性の一例を示す。磁界の大きさに対して偶関数的な特性を持ち、インピーダンス値が単調減少する。媒体２３が無い状態で、磁界検出素子１３のバイアス点はＨｂの位置にあり、媒体２３の近接によって（Ｈｂ＋Ｈｍ）の点に移動する。この時のインピーダンス変化ΔＺは負の値となる。 FIG. 3 shows an example of element characteristics. It has an even function with respect to the magnitude of the magnetic field, and the impedance value decreases monotonously. In the state where there is no medium 23, the bias point of the magnetic field detection element 13 is at the position Hb, and moves to the point (Hb + Hm) by the proximity of the medium 23. The impedance change ΔZ at this time is a negative value.
図４は磁界検出素子として磁気インピーダンス素子を用いた場合の、素子特性とバイアス磁界の設定範囲を示す。また、グラフの下に、磁性膜の磁区構造の模式図を示す。磁界検出方向は、磁性膜のパターン長方向である。図４（ａ）のグラフは磁性膜のパターン長方向（図中のＥ方向）に磁気異方性を付与した時に得られる磁界−インピーダンス特性である。このとき、ゼロ磁界を中心にした±Ｈｃの範囲では、磁性膜はＥ方向に沿って互いに逆向きの磁化を持つ領域が混在した磁区構造を取り、±Ｈｃを越えた領域では、印加磁界Ｈの方向の磁化領域が成長して、磁化Ｍが揃った構造を取る。 FIG. 4 shows the element characteristics and the setting range of the bias magnetic field when a magnetic impedance element is used as the magnetic field detection element. Moreover, the schematic diagram of the magnetic domain structure of a magnetic film is shown under a graph. The magnetic field detection direction is the pattern length direction of the magnetic film. The graph of FIG. 4A is a magnetic field-impedance characteristic obtained when magnetic anisotropy is imparted in the pattern length direction (E direction in the figure) of the magnetic film. At this time, in the range of ± Hc centered on the zero magnetic field, the magnetic film has a magnetic domain structure in which regions having magnetizations opposite to each other along the E direction are mixed, and in the region exceeding ± Hc, the applied magnetic field H The magnetization region in the direction of is grown to take a structure in which the magnetization M is aligned.
図４（ｂ）のグラフはパターン幅方向（図中のＥ´方向）に磁気異方性を付与した場合に得られる特性である。この場合も同様に、ゼロ磁界を中心にした±Ｈｃの範囲では、磁性膜はＥ´方向に沿って互いに逆向きの磁化を持つ領域が混在した磁区構造を取り、±Ｈｃを越えた領域では、印加磁界Ｈの方向に磁化が回転して、磁化Ｍが揃った構造を取る。通常、磁気インピーダンス素子は図４（ｂ）の特性で使用され、ハッチングで示されたＢまたはＢ´の磁界範囲にバイアス磁界Ｈｂが設定される。 The graph of FIG. 4B shows characteristics obtained when magnetic anisotropy is imparted in the pattern width direction (E ′ direction in the figure). Similarly, in this case, in the range of ± Hc centered on the zero magnetic field, the magnetic film has a magnetic domain structure in which regions having magnetizations opposite to each other along the E ′ direction are mixed, and in a region exceeding ± Hc, The structure is such that the magnetization rotates in the direction of the applied magnetic field H and the magnetization M is uniform. Normally, the magneto-impedance element is used with the characteristics shown in FIG. 4B, and the bias magnetic field Hb is set in the magnetic field range of B or B ′ indicated by hatching.
しかし、この場合には設定範囲の幅が非常に狭く、高々２〜３Ｏｅ程度である。これに対して、ＡまたはＡ´の磁界範囲に設定すると、感度は低下するが、ＢまたはＢ´と同様の感度ばらつきが得られる範囲が大幅に拡大し、１０〜２０Ｏｅの幅に広がる。図４（ａ）の特性でＡまたはＡ´の磁界範囲に設定しても同様である。図２の構成において、バイアス点は磁石に対する磁界検出素子の配置で決まるため、適正なバイアス点に設定するための配置の位置精度を、ＡまたはＡ´の磁界範囲では大幅に緩和することができる。 However, in this case, the width of the setting range is very narrow, about 2 to 3 Oe at most. On the other hand, when the magnetic field range is set to A or A ′, the sensitivity is lowered, but the range in which the sensitivity variation similar to B or B ′ is obtained is greatly expanded and widens to 10 to 20 Oe. This is the same even if the magnetic field range of A or A ′ is set in the characteristics shown in FIG. In the configuration of FIG. 2, since the bias point is determined by the arrangement of the magnetic field detection element with respect to the magnet, the positional accuracy of the arrangement for setting an appropriate bias point can be greatly relaxed in the magnetic field range of A or A ′. .
ＡまたはＡ´の磁界範囲では、磁性膜内の磁化がほぼ磁界検出方向に飽和しているため、外部磁界が変化しても磁壁の移動に伴うヒステリシスやノイズが出にくい。このため、感度は低下するが、感度／ノイズ比でみると、特性の大幅な低下はない。 In the magnetic field range of A or A ′, the magnetization in the magnetic film is almost saturated in the magnetic field detection direction. Therefore, even if the external magnetic field changes, hysteresis and noise associated with the movement of the domain wall are difficult to occur. For this reason, the sensitivity is reduced, but there is no significant reduction in characteristics in terms of the sensitivity / noise ratio.
図５は媒体の近接方法による磁界検出素子のインピーダンス変化の違いを示す。図５（ａ）は媒体２３が磁界検出素子１３から遠い方の磁極に近接した場合の変化であり、図５（ｂ）は近い方の磁極に近接した場合の変化である。図５（ａ）では媒体２３による磁界変化Ｈｍはバイアス磁界Ｈｂが増加する方向であり、図５（ａ）のＯ点からＰ点、Ｑ点と移動しても磁界検出素子の特性上問題がない。 FIG. 5 shows the difference in impedance change of the magnetic field detection element depending on the method of approaching the medium. FIG. 5A shows the change when the medium 23 is close to the magnetic pole far from the magnetic field detection element 13, and FIG. 5B is the change when the medium 23 is close to the near magnetic pole. In FIG. 5A, the magnetic field change Hm due to the medium 23 is the direction in which the bias magnetic field Hb increases, and there is a problem in the characteristics of the magnetic field detecting element even if it moves from the O point to the P point and the Q point in FIG. Absent.
一方、図５（ｂ）では磁界変化Ｈｍはバイアス磁界Ｈｂが減少する方向であり、Ｏ点からＰ′点、Ｑ′点へと移動すると、インピーダンス値が増加から減少に転じ、変化が媒体２３の磁気量に対応しなくなってしまう。図５では図４（ｂ）の特性を用いて説明したが、図４（ａ）の特性でもゼロ磁界を中心にある磁界範囲では特性が不安定であり、動作点がその領域に入ると動作不良となる。このように媒体の磁気量が大きい用途では、図５（ａ）の近接方法が好ましい。 On the other hand, in FIG. 5B, the magnetic field change Hm is a direction in which the bias magnetic field Hb decreases. When the magnetic field change Hm moves from the O point to the P ′ point and the Q ′ point, the impedance value changes from increasing to decreasing, and the change changes. It will not correspond to the amount of magnetism. Although FIG. 5 has been described using the characteristics of FIG. 4B, the characteristics of FIG. 4A are also unstable in the magnetic field range centered on the zero magnetic field, and operate when the operating point enters that region. It becomes defective. In such applications where the magnetic amount of the medium is large, the proximity method shown in FIG.
図６は磁界検出素子として磁気インピーダンス素子を用いた場合の駆動回路を示す。発振部はＣＭＯＳを用いたパルス発振回路であり、これが最も望ましいが、特に限定されるものではない。図６（ａ）の例ではパルス電流はＡＣ結合を通じて正負交互に振れる電流として素子に通電され、磁性膜のヒステリシスを低減する効果を持っている。 FIG. 6 shows a drive circuit when a magnetic impedance element is used as the magnetic field detection element. The oscillating unit is a pulse oscillating circuit using CMOS, which is most desirable, but is not particularly limited. In the example of FIG. 6A, the pulse current is passed through the element as a current that alternates between positive and negative through AC coupling, and has the effect of reducing the hysteresis of the magnetic film.
検波回路はダイオードを用いた構成になっているが、スイッチを用いた方法でも同様に構成可能であり、磁界検出素子１３のインピーダンス値に応じた信号が出力される。図６（ｂ）の例は図品点数を減らして、通電するパルス電流を、プラス側にのみ振れるものとした構成である。図４（ｂ）に示す通常使用される範囲においては、この構成ではヒステリシスが大きくなり好ましくないが、単調減少領域では可能である。この回路は本発明の構成を最も活かした回路であり、ヒステリシス等の特性劣化無く回路規模を従来のものより低減できる。 Although the detection circuit has a configuration using a diode, it can be similarly configured by a method using a switch, and a signal corresponding to the impedance value of the magnetic field detection element 13 is output. The example of FIG. 6B has a configuration in which the number of illustrated items is reduced and the energized pulse current can swing only to the plus side. In the normally used range shown in FIG. 4B, this configuration is not preferable because the hysteresis becomes large, but it is possible in the monotonously decreasing region. This circuit is the circuit that makes the most of the configuration of the present invention, and can reduce the circuit scale from the conventional one without deterioration of characteristics such as hysteresis.
次に、本発明の媒体の検出方法について説明する。媒体の検出は媒体を停止させて行っても良いし、センサと相対的に移動させて連続的に検出しても良い。図７は磁石の磁極面と平行に移動させて連続的に検出する場合の、媒体の移動方向と出力信号の例を示す。図７（ａ）は磁界検出素子の磁界検出方向と直交する方向にストライプ状の媒体を移動させた場合の出力例である。 Next, the medium detection method of the present invention will be described. The medium may be detected by stopping the medium, or may be detected continuously by moving relative to the sensor. FIG. 7 shows an example of the moving direction of the medium and the output signal in the case of detecting continuously by moving parallel to the magnetic pole surface of the magnet. FIG. 7A shows an output example when the stripe-shaped medium is moved in a direction orthogonal to the magnetic field detection direction of the magnetic field detection element.
この移動方向では磁気を有する領域が磁極上を通過するタイミングで、パターンの磁気量に応じた山が検出される。これに対して、磁界検出方向と平行に移動させた場合の出力は図７（ｂ）のようになり、タイミングが多少ずれて、且つ、磁気量に応じた山の両側にオーバーシュートが現れる。このため、通常の磁気量検出では図７（ａ）に示すように磁界検出方向と直交する方向に移動させるのが望ましい。 In this moving direction, a peak corresponding to the magnetic amount of the pattern is detected at the timing when the magnetic region passes over the magnetic pole. On the other hand, the output when moved in parallel with the magnetic field detection direction is as shown in FIG. 7B, the timing is slightly shifted, and overshoots appear on both sides of the mountain according to the amount of magnetism. For this reason, in normal magnetic quantity detection, it is desirable to move in a direction orthogonal to the magnetic field detection direction as shown in FIG.
次に、微量な磁気量を精度良く検出する際に有効な構成を説明する。図８は磁石１２と２つの磁界検出素子１３、１４を用いた構成で、それらは図１と同様に同一平面に配置されている。図８では図１と同一部分には同一符号を付している。磁界検出素子１３、１４は磁界検出方向を同一にして、その方向に並べて配置されている。 Next, a configuration effective for detecting a minute amount of magnetic quantity with high accuracy will be described. FIG. 8 shows a configuration using a magnet 12 and two magnetic field detection elements 13 and 14, which are arranged on the same plane as in FIG. In FIG. 8, the same parts as those in FIG. The magnetic field detection elements 13 and 14 are arranged side by side in the same magnetic field detection direction.
この構成での検出原理を図９及び図１０を用いて説明する。図９（ａ）は図８を上から見た図、図９（ｂ）は図８を正面から見た図である。図９において、磁界検出素子１３、１４はｙ方向が磁界検出方向であり、磁石１２から互いに逆方向のバイアス磁界Ｈｂを受ける。バイアス磁界の大きさは図１の場合と同様に磁石１２のＮＳ間距離と、磁界検出素子の位置により適当に設定することができる。 The detection principle in this configuration will be described with reference to FIGS. 9A is a view of FIG. 8 viewed from above, and FIG. 9B is a view of FIG. 8 viewed from the front. In FIG. 9, the magnetic field detection elements 13 and 14 have a magnetic field detection direction in the y direction and receive bias magnetic fields Hb in opposite directions from the magnet 12. The magnitude of the bias magnetic field can be appropriately set according to the distance between the NS of the magnet 12 and the position of the magnetic field detection element as in the case of FIG.
媒体２３は磁石１２のＮＳ軸に対して対称に磁化され、磁界検出素子１３、１４は互いに逆方向の磁界Ｈｍを受ける。図１０（ａ）は磁界検出方向の位置による磁界分布であり、媒体２３の有無により実線から点線の分布へと変化する。 The medium 23 is magnetized symmetrically with respect to the NS axis of the magnet 12, and the magnetic field detection elements 13, 14 receive magnetic fields Hm in opposite directions. FIG. 10A shows a magnetic field distribution depending on the position in the magnetic field detection direction, and changes from a solid line to a dotted line depending on the presence or absence of the medium 23.
磁界検出素子１３、１４は、この磁界分布の中央付近を除いた変化の少ない位置に配置されている。図１０（ｂ）は素子特性の一例を示す。磁界の大きさに対して偶関数的な特性を持ち、インピーダンス値が単調減少する。媒体２３が無い状態で、磁界検出素子１３及び１４のバイアス点は−Ｈｂ及びＨｂの位置にあり、媒体２３の近接によって−（Ｈｂ＋Ｈｍ）、及び、（Ｈｂ＋Ｈｍ）の点に移動する。 The magnetic field detection elements 13 and 14 are arranged at positions with little change except for the vicinity of the center of the magnetic field distribution. FIG. 10B shows an example of element characteristics. It has an even function with respect to the magnitude of the magnetic field, and the impedance value decreases monotonously. In the state where the medium 23 is not present, the bias points of the magnetic field detection elements 13 and 14 are at the positions of −Hb and Hb, and move to the points of − (Hb + Hm) and (Hb + Hm) by the proximity of the medium 23.
この時のインピーダンス変化ΔＺは磁界検出素子１３、１４で同じであり、それらの和をとることで２ΔＺの変化が得られる。図１０（ｃ）は外部磁界Ｈｅｘが加わった場合の変化を示す。素子特性及びバイアス点は図１０（ｂ）と同様である。磁界検出素子１３及び１４のバイアス点は、−Ｈｂ＋Ｈｅｘ、及び、Ｈｂ＋Ｈｅｘへ移動し、インピーダンス変化ΔＺｂ及びΔＺａが生じる。 The impedance change ΔZ at this time is the same in the magnetic field detection elements 13 and 14, and a change of 2ΔZ can be obtained by taking the sum of them. FIG. 10C shows a change when the external magnetic field Hex is applied. The element characteristics and the bias point are the same as in FIG. The bias points of the magnetic field detection elements 13 and 14 move to −Hb + Hex and Hb + Hex, and impedance changes ΔZb and ΔZa occur.
素子特性の直線性に対して、外部磁界が充分小さければ、ΔＺｂ＋ΔＺａはゼロとなる。このように磁界検出素子１３、１４のインピーダンスの和を検出することにより、外部磁界を相殺して、媒体２３による変化のみを検出することが可能となる。 If the external magnetic field is sufficiently small relative to the linearity of the element characteristics, ΔZb + ΔZa becomes zero. By detecting the sum of the impedances of the magnetic field detection elements 13 and 14 in this way, it is possible to cancel the external magnetic field and detect only the change caused by the medium 23.
図１１は磁石と磁界検出素子の配置例を示す。磁界検出素子の配置は、図８の配置の他、図１１（ａ）に示すように磁石１２の両側に磁界検出素子１３、１４を配置した構成であっても良い。また、図１１（ｂ）に示すように磁性膜１５、１６を同一の基板２１０上に形成して直列に導電性パターン８００で接続した磁界検出素子１３０を用いた配置であっても良い。 FIG. 11 shows an arrangement example of magnets and magnetic field detection elements. The arrangement of the magnetic field detection elements may be the arrangement in which the magnetic field detection elements 13 and 14 are arranged on both sides of the magnet 12 as shown in FIG. Further, as shown in FIG. 11B, an arrangement using magnetic field detecting elements 130 in which the magnetic films 15 and 16 are formed on the same substrate 210 and connected in series by the conductive pattern 800 may be used.
同一基板上に形成したものでは、製造の検査工程で特性チェック等をする場合には、中点電極１８が設けられ、２つの磁界検出素子を別個に評価できる図１１（ｃ）の構成の方が望ましい。 In the case of performing the characteristic check etc. in the manufacturing inspection process, the one formed on the same substrate is provided with a midpoint electrode 18, and the configuration of FIG. 11C in which the two magnetic field detecting elements can be evaluated separately. Is desirable.
図１１（ｄ）は補助磁石１２０、１２１を用いた構成を示す。図１１（ｅ）は補助磁石１２０を用いた構成を示す。どちらの構成も、媒体に発生する磁化の磁界検出素子の磁界検出方向成分を増強するように、媒体に磁界を加える配置であり、検出前の残留磁化が大きい媒体等に有効に作用する。 FIG. 11D shows a configuration using auxiliary magnets 120 and 121. FIG. 11E shows a configuration using the auxiliary magnet 120. Both configurations are arrangements in which a magnetic field is applied to the medium so as to enhance the magnetic field detection direction component of the magnetic field detection element of the magnetization generated in the medium, which effectively acts on a medium having a large residual magnetization before detection.
図１１（ｆ）、図１１（ｇ）も補助磁石１２０を用いた構成を示す。図１１（ｆ）は磁界検出素子が１個の構成で、磁界検出方向をＮＳ軸の動径方向から角度を持たせつつ、媒体を確実に磁化して安定した検出を可能にした構成である。磁気量の勾配を検出する場合には、図１１（ｇ）に示すように磁石１２と補助磁石１２０の間に磁界検出素子１３、１４を配置した構成も可能である。この構成では、バイアス磁界は２つの素子で同方向に印加されるため、通常の差動検出が行われる。 FIG. 11F and FIG. 11G also show a configuration using the auxiliary magnet 120. FIG. 11F shows a configuration in which a single magnetic field detection element is used, and the medium is reliably magnetized and stable detection is possible while the magnetic field detection direction is angled from the radial direction of the NS axis. . In the case of detecting the gradient of the magnetic quantity, a configuration in which the magnetic field detection elements 13 and 14 are arranged between the magnet 12 and the auxiliary magnet 120 as shown in FIG. In this configuration, since the bias magnetic field is applied in the same direction by two elements, normal differential detection is performed.
図１２は２つの磁気インピーダンス素子を用いた場合の駆動回路を示す。図１２（ａ）の駆動回路は図８及び図１１（ａ）、図１１（ｃ）の構成に適用できるものであり、２つの磁界検出素子１３、１４夫々の一方の電極は接地され、夫々のインピーダンス値に応じた出力が検波後に加算され、Ｖｏｕｔとして出力される。 FIG. 12 shows a drive circuit when two magneto-impedance elements are used. The drive circuit shown in FIG. 12A can be applied to the configurations shown in FIGS. 8, 11A, and 11C. One electrode of each of the two magnetic field detection elements 13 and 14 is grounded, and Outputs corresponding to the impedance values are added after detection and output as Vout.
この回路では、２つの磁界検出素子の検波後出力Ｓ１、Ｓ２をモニターすることで、バイアス磁界のバランスや感度ばらつき、動作不良等を２つの磁界検出素子で別々に検査することができる。 In this circuit, the post-detection outputs S1 and S2 of the two magnetic field detection elements can be monitored to separately inspect the bias magnetic field balance, sensitivity variation, operation failure, and the like using the two magnetic field detection elements.
図１２（ｂ）の駆動回路は図１２（ａ）にバランス調整機能とオフセットのリセット機能を加えたものである。バランス調整機能は２つの磁界検出素子の感度ばらつきがある場合にそれを補正する。リセット機能はダイオードの温度特性による出力レベル変動の補正や参照媒体との比較検出に用いられる。 The drive circuit in FIG. 12B is obtained by adding a balance adjustment function and an offset reset function to FIG. The balance adjustment function corrects the sensitivity variation between the two magnetic field detection elements. The reset function is used for correction of output level fluctuations due to the temperature characteristics of the diode and for comparison detection with a reference medium.
図１２（ｃ）は２つの磁界検出素子を直列に接続し、従来の１素子分の回路で駆動を可能にした例であり、磁界検出素子以外は図６（ｂ）と同じである。本発明による駆動回路の省スペース化の効果は２つの磁界検出素子を用いた構成でより大きい。 FIG. 12C shows an example in which two magnetic field detection elements are connected in series and can be driven by a conventional circuit for one element, and the other elements are the same as those in FIG. 6B. The effect of saving the space of the drive circuit according to the present invention is greater in the configuration using two magnetic field detection elements.
次に、媒体の移動方向と出力信号の例を図１３に示す。図１３（ａ）は磁界検出素子の磁界検出方向と直交する方向にストライプ状の媒体２３を移動させた場合の出力例である。この移動方向ではパターンの磁気量に応じた山が検出される。これに対して、磁界検出方向と平行に移動させた場合の出力は図１３（ｂ）に示すようになり、パターンが細かくなると、１つのパターンに対して２つの山が現れるようになる。 Next, FIG. 13 shows an example of the moving direction of the medium and the output signal. FIG. 13A shows an output example when the striped medium 23 is moved in a direction orthogonal to the magnetic field detection direction of the magnetic field detection element. In this movement direction, a peak corresponding to the magnetic quantity of the pattern is detected. On the other hand, the output when moved in parallel with the magnetic field detection direction is as shown in FIG. 13B, and when the pattern becomes fine, two peaks appear for one pattern.
モーター等の媒体の搬送系からのノイズ磁界を避けるために磁界検出方向が限定されてしまう場合等を除いて、図１３（ａ）に示すように磁界検出方向と直交する方向に移動させるのが望ましい。 Except for the case where the magnetic field detection direction is limited in order to avoid a noise magnetic field from a medium conveyance system such as a motor, the movement is performed in a direction orthogonal to the magnetic field detection direction as shown in FIG. desirable.
次に、本発明の実施例を説明する。なお、以下の説明において、高精度な検出を行う場合を想定した図８の基本構成の実施例を挙げて説明するが、図１の構成であっても同様に実施可能である。 Next, examples of the present invention will be described. In the following description, an example of the basic configuration of FIG. 8 assuming the case of performing highly accurate detection will be described, but the configuration of FIG. 1 can be similarly implemented.
図１４は本実施例による磁性体検出センサ１を示す。図１４では磁性体検出センサ１の内部を上から見た図と側面から見た図を示す。磁石１２と磁界検出素子１３０は駆動回路基板２９に面実装され、それらを囲うようにシールド２４、ホルダー２６、ケース２５が配置されている。磁石１２と磁界検出素子１３０の間隔は０．５ｍｍ、ケース２５の外形は約６×６×０．７ｍｍ３であり、従来よりも小型化、薄型化が実現できている。 FIG. 14 shows a magnetic substance detection sensor 1 according to this embodiment. In FIG. 14, the figure which looked at the inside of the magnetic body detection sensor 1 from the top, and the figure seen from the side are shown. The magnet 12 and the magnetic field detection element 130 are surface-mounted on the drive circuit board 29, and a shield 24, a holder 26, and a case 25 are disposed so as to surround them. The distance between the magnet 12 and the magnetic field detection element 130 is 0.5 mm, and the outer shape of the case 25 is about 6 × 6 × 0.7 mm 3. Thus, the size and thickness can be reduced as compared with the conventional case.
磁石１２には、磁極面積１ｍｍ×１ｍｍ、高さ０．６ｍｍのネオジム磁石を用いている。磁界検出素子１３０は基板２１０上に磁性膜１５、１６が形成され、それらは直列に接続されて、その両端に電極１７、２０が形成されている。基板２１０には０．２ｍｍ厚のチタン酸カルシウムのセラミック基板を用いている。 The magnet 12 is a neodymium magnet having a magnetic pole area of 1 mm × 1 mm and a height of 0.6 mm. In the magnetic field detection element 130, magnetic films 15 and 16 are formed on a substrate 210, which are connected in series, and electrodes 17 and 20 are formed at both ends thereof. The substrate 210 is a 0.2 mm-thick calcium titanate ceramic substrate.
磁性膜１５、１６は、正磁歪を有するＦｅ−Ｔａ−Ｃ系の磁性材をスパッタで成膜した後、イオンミリングにより加工し、幅３０μｍ、長さ１ｍｍ、膜厚１８００ｎｍのパターンを接続してつづら折れ状に形成されている。電極１７、２０及び磁性膜１５、１６の接続にはＣｕを用い、リフトオフプロセスにより形成されている。電極を除く基板上には、磁性膜を覆うように図示しない保護膜がスピンコートとフォトリソグラフィープロセスにより形成されている。 The magnetic films 15 and 16 are formed by sputtering a Fe—Ta—C-based magnetic material having positive magnetostriction and then processed by ion milling to connect a pattern having a width of 30 μm, a length of 1 mm, and a film thickness of 1800 nm. It is formed in a zigzag shape. The electrodes 17 and 20 and the magnetic films 15 and 16 are connected using Cu and formed by a lift-off process. A protective film (not shown) is formed on the substrate excluding the electrodes by spin coating and a photolithography process so as to cover the magnetic film.
電極１７、２０は駆動回路基板２９上の図示しない銅箔パターンと電気的に接続され、磁界検出素子１３０は高周波電流を印加することにより、磁気インピーダンス素子として動作する。シールド２４は板厚０．２５ｍｍの７８％Ｎｉパーマロイ板で形成され、磁界検出素子１３０と磁石１２を囲むように配置されている。ケース２５は０．１ｍｍ厚のリン青銅で形成され、媒体との対向面には無電解Ｎｉメッキが施されている。ケース２５は駆動回路基板２９のグラウンドと電気的に接続されている。 The electrodes 17 and 20 are electrically connected to a copper foil pattern (not shown) on the drive circuit board 29, and the magnetic field detection element 130 operates as a magnetic impedance element by applying a high frequency current. The shield 24 is formed of a 78% Ni permalloy plate having a thickness of 0.25 mm, and is disposed so as to surround the magnetic field detection element 130 and the magnet 12. The case 25 is made of phosphor bronze having a thickness of 0.1 mm, and the surface facing the medium is subjected to electroless Ni plating. The case 25 is electrically connected to the ground of the drive circuit board 29.
本実施例では、磁界検出素子として磁気インピーダンス素子を用いているため、磁界検出感度が高い反面、磁界−インピーダンス特性において良好な直線性が得られる範囲が狭い。その範囲を越えると、２つの磁界検出素子でのノイズ磁界に対するキャンセル効果が低下する。 In this embodiment, since the magnetic impedance element is used as the magnetic field detection element, the magnetic field detection sensitivity is high, but the range in which good linearity is obtained in the magnetic field-impedance characteristic is narrow. If the range is exceeded, the canceling effect on the noise magnetic field in the two magnetic field detection elements is reduced.
このため、磁気シールド２４によりノイズ磁界を低減することは、媒体の検出精度向上に大きな効果がある。また、高周波電流を用いるため、媒体との静電容量によりセンサ出力がオフセットする場合がある。ケース２５は電気シールドとしての機能も持ち、磁界検出素子の動作を安定化する。 For this reason, reducing the noise magnetic field by the magnetic shield 24 has a great effect on improving the medium detection accuracy. In addition, since a high-frequency current is used, the sensor output may be offset due to the capacitance with the medium. The case 25 also has a function as an electric shield and stabilizes the operation of the magnetic field detection element.
図１５は磁石１２と磁界検出素子１３０の実装例を示す。図１５（ａ）の例では磁石１２と磁界検出素子１３０がプリント基板３２に実装され、端子２７によって外部の駆動回路に接続されている。 FIG. 15 shows a mounting example of the magnet 12 and the magnetic field detection element 130. In the example of FIG. 15A, the magnet 12 and the magnetic field detection element 130 are mounted on the printed circuit board 32 and are connected to an external drive circuit by a terminal 27.
図１５（ｂ）の例では、磁石１２、磁界検出素子１３０、駆動回路３３がプリント基板３２の同一面に実装されている。本実施例によれば、駆動回路の省スペース化も可能であり、図１５（ｂ）に示す駆動回路一体型の使い勝手の良い磁性体検出センサも容易に構成できる。なお、図１５中、３０ははんだ、３１は銅配線を示す。 In the example of FIG. 15B, the magnet 12, the magnetic field detection element 130, and the drive circuit 33 are mounted on the same surface of the printed board 32. According to the present embodiment, it is possible to save the space of the drive circuit, and the easy-to-use magnetic body detection sensor integrated with the drive circuit shown in FIG. In FIG. 15, 30 indicates solder and 31 indicates copper wiring.
図１６は本発明の磁性体検出センサ１を用いた磁性体検出装置の一実施例としてのエンコーダを示す。図中１は磁性体検出センサ、２は磁性体検出装置、３３は駆動回路を示す。磁性体検出センサ１には、例えば、図１４の構成を用いることができ、駆動回路３３には、例えば、図１２（ｃ）の回路を用いることができる。媒体２３１は磁性材が一定の間隔で配置されたもので、磁性材料を加工したものの他、磁性薄膜のパターンや磁気インク等の印刷で形成されたものでも良い。 FIG. 16 shows an encoder as an embodiment of a magnetic body detection apparatus using the magnetic body detection sensor 1 of the present invention. In the figure, 1 is a magnetic substance detection sensor, 2 is a magnetic substance detection device, and 33 is a drive circuit. For example, the configuration shown in FIG. 14 can be used for the magnetic substance detection sensor 1, and the circuit shown in FIG. 12C can be used for the drive circuit 33, for example. The medium 231 includes magnetic materials arranged at regular intervals, and may be formed by printing a magnetic thin film pattern, magnetic ink, or the like in addition to a magnetic material processed.
媒体２３１が磁性体検出センサ１に対して相対的に移動することにより、出力Ｖｏｕｔが変化し、参照電圧Ｖｒｅｆを基準としてコンパレータ３５により出力変化をパルス化する。また、そのパルス信号をカウンタ３６でカウントすることによりエンコーダとして動作する。 As the medium 231 moves relative to the magnetic substance detection sensor 1, the output Vout changes, and the output change is pulsed by the comparator 35 with the reference voltage Vref as a reference. The pulse signal is counted by the counter 36 so as to operate as an encoder.
本発明の磁性体検出センサは、磁気インク等の印刷媒体に対しても充分な感度を有していて、媒体を選ばない。印刷媒体であればピッチや形状も簡単に変更することができる。これにより、安価で汎用性の高いエンコーダを構成できる。 The magnetic substance detection sensor of the present invention has sufficient sensitivity to a print medium such as magnetic ink, and any medium can be selected. If it is a printing medium, a pitch and a shape can also be changed easily. Thereby, an inexpensive and highly versatile encoder can be configured.
図１７及び図１８は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としてのエンコーダの他の例を示す。図１８中に磁性体検出センサの磁界検出素子１３、１４、を示す。２は磁性体検出装置である。図１７に示すように磁石１２の両側に磁界検出素子１３、１４が配置され、媒体２３１は２つの磁界検出素子が配置された方向に移動する。磁界検出素子１３、１４のインピーダンス値に応じた出力が図１８の装置で参照電圧Ｖｒｅｆを基準として夫々パスル化され、Ａ及びＢの出力が得られる。Ａ及びＢの出力をカウンタ３６でカウントすることでエンコーダ出力が得られる。 17 and 18 show another example of an encoder as an embodiment of a magnetic body detection device using the magnetic body detection sensor of the present invention. FIG. 18 shows magnetic field detection elements 13 and 14 of the magnetic substance detection sensor. Reference numeral 2 denotes a magnetic substance detection device. As shown in FIG. 17, the magnetic field detection elements 13, 14 are arranged on both sides of the magnet 12, and the medium 231 moves in the direction in which the two magnetic field detection elements are arranged. The outputs corresponding to the impedance values of the magnetic field detection elements 13 and 14 are pulsed with the reference voltage Vref as a reference in the apparatus of FIG. 18, and outputs A and B are obtained. The encoder output is obtained by counting the outputs of A and B by the counter 36.
図１７の構成は磁石１２を共通にして図１の構成が２つ配置されており、夫々の出力は図６（ｂ）に示すようにタイミングがずれる。このため、図１９に示すようにＡ及びＢの出力信号は媒体の移動に対して位相のずれたパルスになる。そこで、図１８に示すように移動方向検知回路３７で２つのパルス出力の立ち上がり順を検出することで、媒体の移動方向も検知することが可能となる。 The configuration of FIG. 17 has the same magnet 12 and two configurations of FIG. 1 are arranged, and the respective outputs are shifted in timing as shown in FIG. 6B. For this reason, as shown in FIG. 19, the output signals of A and B are pulses whose phases are shifted with respect to the movement of the medium. Therefore, as shown in FIG. 18, the moving direction detection circuit 37 detects the rising order of the two pulse outputs, so that the moving direction of the medium can also be detected.
媒体の磁気量が小さく、地磁気等のノイズ磁界の影響が大きい場合には、図２０に示すように磁石１２を共通にして、その両側に図８の構成を２つ配置したものも同様に用いることができる。このように本発明の磁性体検出装置は磁性体検出センサが磁石を共通にして２つ配置されている構成をとることができる。 When the magnetic quantity of the medium is small and the influence of a noise magnetic field such as geomagnetism is large, a magnet 12 is used in common as shown in FIG. 20, and two configurations shown in FIG. be able to. Thus, the magnetic body detection device of the present invention can take a configuration in which two magnetic body detection sensors are arranged with a common magnet.
媒体の磁気量が非常に大きい場合、例えば、磁性体板を加工したもの等の場合には、磁性体が磁極上を通過する際に吸引力が働き、移動に抵抗力が発生する。この磁性体が自由に移動または回転可能に保持されていれば、磁性体は磁極上で停止する。これを利用し、磁極上を通過した磁性体の数と移動方向を検知することで、抵抗力により操作感を発生させる入力デバイスを構成することができる。この入力デバイスは、例えば、携帯電話機或いはＡＶ機器等に使用されている回転型セレクタ（ジョグダイヤル）として好適に用いることが可能である。 When the magnetic amount of the medium is very large, for example, when a magnetic plate is processed, an attractive force acts when the magnetic material passes over the magnetic pole, and a resistance force is generated for the movement. If the magnetic body is held so as to be freely movable or rotatable, the magnetic body stops on the magnetic pole. By utilizing this and detecting the number of magnetic bodies that have passed over the magnetic poles and the direction of movement, an input device that generates a feeling of operation by resistance can be configured. This input device can be suitably used as, for example, a rotary selector (jog dial) used in a mobile phone or AV equipment.
図２１、図２２はその構成の一例を示す。図２１は筒状の媒体２３３を回転させ、図２２は円盤状の媒体２３４を回転させることで入力デバイスとして機能する。本発明の磁性体検出センサを用いれば、非常に薄型で、且つ、部品点数も少なく安価な入力デバイスを構成できる。 21 and 22 show an example of the configuration. FIG. 21 functions as an input device by rotating a cylindrical medium 233 and FIG. 22 rotates a disk-shaped medium 234. By using the magnetic substance detection sensor of the present invention, it is possible to construct an inexpensive input device that is very thin and has a small number of parts.
本発明の入力デバイスの構成は、磁性体検出センサが、磁石を共通にして２つ配置されている磁性体検出装置と、予め設定された間隔で磁性体が配置された可動部材（筒状の媒体２３３又は円盤状の媒体２３４）とを備えている。また２つの磁性体検出センサの出力の夫々を予め決められた閾値でパルス化する回路と、可動部材の移動に応じて出力される２つのパルス信号の位相差とパルス数によって可動部材の移動量及び移動方向を検出する回路とを備えることで構成する。 The configuration of the input device of the present invention includes a magnetic body detection device in which two magnetic body detection sensors are arranged with a common magnet, and a movable member (a cylindrical member) in which the magnetic body is disposed at a predetermined interval. Medium 233 or disk-shaped medium 234). Further, the amount of movement of the movable member is determined by a circuit for pulsing each of the outputs of the two magnetic substance detection sensors with a predetermined threshold, and the phase difference and the number of pulses of the two pulse signals output according to the movement of the movable member. And a circuit for detecting the moving direction.
図２３は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての磁気量検出装置を示す。図中１は磁性体検出センサ、２は磁性体検出装置、３３は駆動回路である。磁性体検出センサ１には、例えば、図１４の構成を用いることができ、駆動回路３３には、例えば、図１２（ｃ）の回路を用いることができる。 FIG. 23 shows a magnetic quantity detection device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. In the figure, 1 is a magnetic substance detection sensor, 2 is a magnetic substance detection device, and 33 is a drive circuit. For example, the configuration shown in FIG. 14 can be used for the magnetic substance detection sensor 1, and the circuit shown in FIG. 12C can be used for the drive circuit 33, for example.
図２３の磁気量検出装置の動作は、まず、図２３（ａ）に示すように参照媒体２３０が近接している状態、又は媒体が無い状態でのセンサ駆動回路３３の出力Ｖｏを、Ａ／Ｄコンバータ３８を通してデジタル信号としてメモリ３９に記憶させる。その後、図２３（ｂ）に示すように検出する媒体２３を磁性体検出センサ１に近接させて、その時の出力とメモリ３９に記憶しているＶｏとの差を算出して磁気量を検出する。ＣＰＵ４０はその場合の演算処理を行う。 23, first, the output Vo of the sensor drive circuit 33 in the state where the reference medium 230 is close as shown in FIG. The digital signal is stored in the memory 39 through the D converter 38. Thereafter, as shown in FIG. 23B, the medium 23 to be detected is brought close to the magnetic body detection sensor 1, and the difference between the output at that time and Vo stored in the memory 39 is calculated to detect the magnetic quantity. . The CPU 40 performs arithmetic processing in that case.
微小な磁気量を検出する等精度を要求される用途では、Ｖｏとの差を検出することは有効な手段となる。これにより、小型で高精度な磁気量検出装置が実現できる。図２３と同様の信号処理は、例えば、図１２（ｂ）の駆動回路を用いる等すれば、アナログ回路でも構成可能である。 In applications that require high precision, such as detecting minute magnetic quantities, detecting the difference from Vo is an effective means. Thereby, a small and highly accurate magnetic quantity detection device can be realized. The signal processing similar to that in FIG. 23 can also be configured with an analog circuit, for example, by using the drive circuit in FIG.
図２４は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての変位検出装置を示す。図中１は磁性体検出センサ、２は磁性体検出装置、３３は駆動回路である。磁性体検出センサ１には、例えば、図１４の構成を用いることができ、駆動回路３３には、例えば、図１２（ｃ）の回路を用いることができる。図２４では媒体２３２に磁性材料の濃度を変えたグラデーションパターンが形成されている。媒体２３２は磁性体検出センサと相対的に移動する物体に固定され、磁性体検出センサ１で磁気量を検出することで、物体の移動量を検出することができる。 FIG. 24 shows a displacement detection device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. In the figure, 1 is a magnetic substance detection sensor, 2 is a magnetic substance detection device, and 33 is a drive circuit. For example, the configuration shown in FIG. 14 can be used for the magnetic substance detection sensor 1, and the circuit shown in FIG. 12C can be used for the drive circuit 33, for example. In FIG. 24, a gradation pattern in which the concentration of the magnetic material is changed is formed on the medium 232. The medium 232 is fixed to an object that moves relative to the magnetic detection sensor, and the amount of movement of the object can be detected by detecting the amount of magnetism with the magnetic detection sensor 1.
図２４の構成で、物体がある位置にある時のＶｏを記憶すれば、その位置を基準とした変位量を検出することができる。グラデーションパターンは磁気インク等の印刷で形成でき、濃度勾配やパターンの長さの変更も容易である。これにより、安価で自由度の高い変位検出装置が実現できる。 In the configuration of FIG. 24, if Vo is stored when an object is at a certain position, a displacement amount based on that position can be detected. The gradation pattern can be formed by printing with magnetic ink or the like, and the density gradient and pattern length can be easily changed. Thereby, an inexpensive and highly flexible displacement detection device can be realized.
図２５は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての磁性粒子数検出装置を示す。図中１は磁性体検出センサ、２は磁性体検出装置、３３は駆動回路である。磁性体検出センサ１には、例えば、図１４の構成を用いることができ、駆動回路３３には、例えば、図１２（ｃ）の回路を用いることができる。この磁性粒子数検出装置は、例えば、医療診断に用いられる標識磁性粒子の検出に好適である。磁性粒子からの磁界は微弱であるため、参照媒体２３０と磁性粒子が付着した媒体２３３を順次磁性体検出センサ１に近接させて、出力の差を検出するのが望ましい。 FIG. 25 shows a magnetic particle number detection device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. In the figure, 1 is a magnetic substance detection sensor, 2 is a magnetic substance detection device, and 33 is a drive circuit. For example, the configuration shown in FIG. 14 can be used for the magnetic substance detection sensor 1, and the circuit shown in FIG. 12C can be used for the drive circuit 33, for example. This magnetic particle number detection apparatus is suitable for detecting, for example, labeled magnetic particles used for medical diagnosis. Since the magnetic field from the magnetic particles is weak, it is desirable to detect the difference in output by sequentially bringing the reference medium 230 and the medium 233 to which the magnetic particles are attached in close proximity to the magnetic substance detection sensor 1.
その出力差から、予め作製された粒子数と出力の校正データを用いて粒子数を算出する。本発明の磁性体検出センサは、高感度な磁界検出素子を用いることができるため、非接触での検出が可能であり、粒子の付着による検出誤差を低減できる。これにより、小型で高精度な磁性粒子数検出装置が実現できる。 From the output difference, the number of particles is calculated using the number of particles prepared in advance and the output calibration data. Since the magnetic substance detection sensor of the present invention can use a highly sensitive magnetic field detection element, non-contact detection is possible and detection errors due to adhesion of particles can be reduced. Thereby, a small and highly accurate magnetic particle number detecting device can be realized.
図２６は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての磁気識別装置を示す。図中１は磁性体検出センサ、２は磁性体検出装置、３３は駆動回路である。図２６（ａ）は媒体の検出波形を予め記憶された正規の波形データと比較し、媒体の真偽を判定する。図２６（ｂ）は媒体の種別を判定する。どちらの例も紙幣等の鑑別や識別に用いることができる。 FIG. 26 shows a magnetic identification device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. In the figure, 1 is a magnetic substance detection sensor, 2 is a magnetic substance detection device, and 33 is a drive circuit. FIG. 26A compares the detected waveform of the medium with normal waveform data stored in advance, and determines the authenticity of the medium. FIG. 26B determines the type of the medium. Both examples can be used for discrimination and identification of bills and the like.
具体的には、図２６（ａ）の例では、磁性体検出センサ１からの出力信号がＡ／Ｄコンバータ３８を介してデジタル信号でＣＰＵ４０に取り込まれる。その際、メモリ３９には予め正規の波形データが記憶されており、ＣＰＵ４０の比較部４４で検出波形と正規の波形とを比較することで真偽判定を行う。 Specifically, in the example of FIG. 26A, the output signal from the magnetic body detection sensor 1 is taken into the CPU 40 as a digital signal via the A / D converter 38. At this time, normal waveform data is stored in the memory 39 in advance, and the true / false judgment is performed by comparing the detected waveform with the normal waveform by the comparison unit 44 of the CPU 40.
図２６（ｂ）の例では、予めメモリ３９に媒体の種別毎に正規の波形データが記憶されている。磁性体検出センサ１からの出力信号は同様にＡ／Ｄコンバータ３８を介してデジタル信号でＣＰＵ４０に取り込まれ、ＣＰＵ４０の比較部４４で検出波形とメモリ３９の媒体毎の波形を比較することで媒体の種別判定を行う。 In the example of FIG. 26B, normal waveform data is stored in advance in the memory 39 for each type of medium. Similarly, the output signal from the magnetic body detection sensor 1 is taken into the CPU 40 as a digital signal through the A / D converter 38, and the comparison waveform of the CPU 40 is compared with the waveform of each medium in the memory 39 by the comparison unit 44 of the CPU 40. The type is determined.
図２６の磁性体検出センサ１には、例えば、図２７の構成を用いることができる。図２７では図１４と同一部分には同一部分には同一符号を付している。図２７において、媒体２３は上下を規制されて通路内を進行し、磁性体検出センサはその通路を形成する搬送路形成部材３４と３４０内に配置されている。磁性体検出センサには、図１５（ｂ）に示す駆動回路を同一基板上に配置したものを用いている。 For example, the configuration of FIG. 27 can be used for the magnetic body detection sensor 1 of FIG. In FIG. 27, the same parts as those in FIG. 14 are denoted by the same reference numerals. In FIG. 27, the medium 23 is regulated in the vertical direction and travels in the passage, and the magnetic substance detection sensor is disposed in the transport path forming members 34 and 340 that form the passage. As the magnetic substance detection sensor, a drive circuit shown in FIG. 15B arranged on the same substrate is used.
これにより、センサがスペースを取らず、且つ、媒体が詰まることのない、信頼性の高い磁気識別装置を実現できる。この構成は、本発明の磁性体検出センサが小型であり、また、従来の磁気抵抗素子に比べて非常に感度の高い磁気インピーダンス素子等を用いることができるために実現できるものである。 Thereby, it is possible to realize a highly reliable magnetic identification device in which the sensor does not take up space and the medium is not clogged. This configuration can be realized because the magnetic substance detection sensor of the present invention is small in size, and a magnetic impedance element or the like having a higher sensitivity than a conventional magnetoresistive element can be used.
図２８及び図２９は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての２次元磁気分布検出装置を示す。図２９中に磁性体検出センサ１の磁性膜１５、１６を示す。２は磁性体検出装置である。図２８はセンサ部の構成であり、媒体２３の進行方向と垂直に磁性体検出センサが一列に配置されている。夫々の磁性体検出センサは駆動回路を図示していないが、例えば、図２７と同様の構成であり、夫々にシールドが配置され、磁性体検出センサ間の干渉を防止している。 28 and 29 show a two-dimensional magnetic distribution detection device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. FIG. 29 shows the magnetic films 15 and 16 of the magnetic substance detection sensor 1. Reference numeral 2 denotes a magnetic substance detection device. FIG. 28 shows a configuration of the sensor unit, in which magnetic substance detection sensors are arranged in a line perpendicular to the traveling direction of the medium 23. Although each magnetic body detection sensor does not show a drive circuit, for example, it has the same configuration as that shown in FIG. 27, and a shield is provided for each to prevent interference between the magnetic body detection sensors.
図２９は駆動回路を含む２次元磁気分布検出装置を示す。図２９（ａ）の例は発振回路を共通にして、図１２（ｃ）の駆動回路を磁性体検出センサ毎に配置している。その出力はスイッチ４１の切り換えにより順次読み込まれ、Ａ／Ｄコンバータ３８を介してＣＰＵ４０に出力され、ＣＰＵ４０の処理によって磁気分布が得られる。 FIG. 29 shows a two-dimensional magnetic distribution detector including a drive circuit. In the example of FIG. 29A, the oscillation circuit is shared, and the drive circuit of FIG. 12C is arranged for each magnetic substance detection sensor. The output is sequentially read by switching the switch 41 and output to the CPU 40 via the A / D converter 38, and the magnetic distribution is obtained by the processing of the CPU 40.
図２９（ｂ）の例は夫々の磁性体検出センサの通電と遮断をアンド回路４２によって制御し、通電するセンサを順次切り換えることにより図２９（ａ）と同様の検出を行う。３８はＡ／Ｄコンバータ、４０はＣＰＵを示す。 In the example of FIG. 29B, energization and interruption of each magnetic body detection sensor are controlled by the AND circuit 42, and the same detection as in FIG. 29A is performed by sequentially switching the energized sensors. Reference numeral 38 denotes an A / D converter, and 40 denotes a CPU.
従来の高感度磁界検出素子を用いた磁性体検出センサでは、図２８のようなセンサ部の駆動には、非常に大きな規模の回路が必要となるが、本発明の磁性体検出センサを用いることで、省スペース化が可能になる。磁石と磁界検出素子の実装は、例えば、図３０に示すように同一のプリント基板３２０上に複数の磁界検出素子１３０と磁石１２等を配置したものでも良い。また、センサ部の構成としては、図２８の他に図３１の構成等も同様に可能である。図３１の１２１、１２２は補助磁石を示す。 In a conventional magnetic substance detection sensor using a high-sensitivity magnetic field detection element, a very large circuit is required for driving the sensor unit as shown in FIG. 28, but the magnetic substance detection sensor of the present invention is used. Thus, space saving is possible. For example, the magnets and the magnetic field detection elements may be mounted by arranging a plurality of magnetic field detection elements 130 and magnets 12 on the same printed circuit board 320 as shown in FIG. In addition to the configuration of FIG. 28, the configuration of FIG. Reference numerals 121 and 122 in FIG. 31 denote auxiliary magnets.
図３２及び図３３は本発明の磁性体検出センサを用いた磁性体検出装置の一実施例としての２次元磁気分布検出装置の別の例を示す。図３３中に磁性体検出センサ１の磁界検出素子１５０を示す。２は磁性体検出装置である。図３２（ａ）は図１１（ｄ）の構成をライン配置した構成である。 32 and 33 show another example of a two-dimensional magnetic distribution detection device as an embodiment of a magnetic material detection device using the magnetic material detection sensor of the present invention. FIG. 33 shows a magnetic field detection element 150 of the magnetic substance detection sensor 1. Reference numeral 2 denotes a magnetic substance detection device. FIG. 32A shows a configuration in which the configuration of FIG.
即ち、極性が反対の磁石２と磁界検出素子１５０を一定間隔で配置した構成であり、そのうちの隣り合う２つの磁界検出素子１５０とその間にある磁石２で１つの磁性体検出センサを構成している。また、媒体との対向面を除いて、磁石２と磁界検出素子１５０の配置全体を囲むように磁気シールド２４２を配置している。 That is, the magnets 2 and the magnetic field detection elements 150 having opposite polarities are arranged at regular intervals, and two magnetic field detection elements 150 adjacent to each other and the magnet 2 between them constitute one magnetic substance detection sensor. Yes. Further, the magnetic shield 242 is disposed so as to surround the entire arrangement of the magnet 2 and the magnetic field detection element 150 except for the surface facing the medium.
図３２（ｂ）は図１（ｂ）の構成をライン配置した構成であり、極性が同じ磁石と磁界検出素子が一定間隔で配置されている。図３２（ｃ）は図３２（ｂ）の磁石を長尺の磁石で置き換えた構成である。 FIG. 32B is a configuration in which the configuration of FIG. 1B is arranged in a line, and magnets having the same polarity and magnetic field detection elements are arranged at regular intervals. FIG. 32C shows a configuration in which the magnet of FIG. 32B is replaced with a long magnet.
図３２（ｄ）は図１１（ｆ）の構成をライン配置した構成であり、図３２（ｄ）の右のグラフのように素子の検出感度Ｓｘと媒体に印加される磁界の検出方向成分Ｈｘがライン方向について互い違いに増減する。そのため、検出感度の低い領域を発生する磁化の大きさで補って、ムラの無い検出が可能になる。ここで、図３２に示すように本発明の磁性体検出センサを複数配列することによって磁性体ラインセンサを構成する。 FIG. 32D shows a configuration in which the configuration of FIG. 11F is arranged in a line, and the detection sensitivity component Sx of the element and the detection direction component Hx of the magnetic field applied to the medium as shown in the right graph of FIG. Increase or decrease alternately in the line direction. Therefore, it is possible to perform detection without unevenness by making up for the area of low detection sensitivity by the magnitude of the magnetization. Here, as shown in FIG. 32, a magnetic body line sensor is configured by arranging a plurality of magnetic body detection sensors of the present invention.
図３３はその駆動回路を含む装置構成を示す。図３３では図２９（ａ）と同一部分には同一符号を付している。図３３の駆動回路では、発振回路を共通にして、夫々の磁界検出素子毎に駆動回路が配置されている。 FIG. 33 shows a device configuration including the drive circuit. In FIG. 33, the same parts as those in FIG. In the drive circuit of FIG. 33, the drive circuit is arranged for each magnetic field detection element with the oscillation circuit in common.
図３４はこの構成を用いた場合の信号処理の一例であり、図３２（ａ）の磁性体検出ラインセンサの構成に適用される。図３４に示すように２個（偶数個）の磁界検出素子からの出力を加算部４３により加算することで、ノイズ磁界の影響を除去しながら検出の位置と幅を自由に設定することが可能である。図３４ではセンサの並びから２個のセンサ（２の倍数個単位＝偶数個単位）の加算で差動検出と同様な処理を行う。 FIG. 34 shows an example of signal processing when this configuration is used, and is applied to the configuration of the magnetic substance detection line sensor of FIG. As shown in FIG. 34, by adding the outputs from two (even) magnetic field detection elements by the adder 43, it is possible to freely set the detection position and width while removing the influence of the noise magnetic field. It is. In FIG. 34, processing similar to that of differential detection is performed by adding two sensors (multiple units of 2 = units of even number) from the sensor array.
この構成では、駆動回路は大きくなるが、様々な媒体に対して、センサ部を取り替えることなく、信号処理部分を変更するだけで対応でき、非常に高性能な磁気分布検出装置を実現できる。 With this configuration, the drive circuit becomes large, but it is possible to cope with various media by changing the signal processing part without replacing the sensor part, and an extremely high performance magnetic distribution detecting device can be realized.
１ 磁性体検出センサ
２ 磁性体検出装置
１２、１２０、１２１、１２２ 磁石
１３、１４、１３０、１３１ 磁界検出素子
１５、１６、１５０ 磁性膜
１７、１８、１９、２０ 電極
２１、２２、２１０ 基板
２３、２３０、２３１、２３２、２３３ 媒体
２４、２４１、２４２ シールド
２５ ケース
２６ ホルダー
２７、２８ 端子
２９ 回路基板
３０ はんだ
３１ 銅配線
３２、３２０ プリント基板
３３ 駆動回路
３４、３４０ 搬送路形成部材
３５ コンパレータ
３６ カウンタ
３７ 移動方向検知回路
３８ Ａ／Ｄコンバータ
３９ メモリ
４０ ＣＰＵ
４１ スイッチ
４２ アンド回路
９１、９４、９５ 磁石
９２１、９２２ 磁界検出素子
９３ バイアス磁石
DESCRIPTION OF SYMBOLS 1 Magnetic body detection sensor 2 Magnetic body detection apparatus 12, 120, 121, 122 Magnet 13, 14, 130, 131 Magnetic field detection element 15, 16, 150 Magnetic film 17, 18, 19, 20 Electrode 21, 22, 210 210 Substrate 23 , 230, 231, 232, 233 Medium 24, 241, 242 Shield 25 Case 26 Holder 27, 28 Terminal 29 Circuit board 30 Solder 31 Copper wiring 32, 320 Printed circuit board 33 Drive circuit 34, 340 Conveyance path forming member 35 Comparator 36 Counter 37 Movement direction detection circuit 38 A / D converter 39 Memory 40 CPU
41 Switch 42 AND circuit 91, 94, 95 Magnet 921, 922 Magnetic field detection element 93 Bias magnet
Claims (11)
前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が近接する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、
前記磁性膜は薄膜であって前記平面に沿った磁気異方性を有し且つ前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有し、
前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置している、
ことを特徴とする磁性体検出センサ。 A magnetic body detection sensor comprising a magnet for generating a magnetic field and a magnetic field detection element having a magnetic film for detecting a change in the magnetic field, and detecting a detection medium containing a magnetic material.
The magnetic field detection element is disposed on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet, the NS direction of the magnet being a normal line, and the detected medium is closer to the NS of the NS axis of the magnet. ,
The magnetic film is a thin film, has a magnetic anisotropy along the plane, and has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction,
The magnetic field detecting element is located in a region where the bias magnetic field applied by the magnet saturates the magnetization of the magnetic film of the magnetic field detecting element in the magnetic field detection direction.
A magnetic substance detection sensor.
前記磁石のＮＳ方向を法線とし、前記磁石の該ＮＳ軸の中点よりも前記被検出媒体が近接する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、
前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置し、
前記磁界検出素子は、前記磁石の前記被検出媒体が近接する磁極と反対側の磁極と同一平面上に配置されている、
ことを特徴とする磁性体検出センサ。 A magnetic body detection sensor comprising a magnet for generating a magnetic field and a magnetic field detection element having a magnetic film for detecting a change in the magnetic field, and detecting a detection medium containing a magnetic material.
The magnetic field detection element is arranged on a plane located on the side of the magnetic pole opposite to the magnetic pole of the magnet closer to the detected medium than the midpoint of the NS axis of the magnet, with the NS direction of the magnet as a normal line. And
The magnetic field detection element is located in a region where the bias magnetic field applied by the magnet saturates the magnetization of the magnetic film of the magnetic field detection element in the magnetic field detection direction,
The magnetic field detection element is disposed on the same plane as the magnetic pole on the side opposite to the magnetic pole close to the detected medium of the magnet.
A magnetic substance detection sensor.
前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が接近する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、NS ,
前記磁性膜は薄膜であって前記平面に沿った磁気異方性を有し且つ前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有する、The magnetic film is a thin film, has a magnetic anisotropy along the plane, and has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction,
ことを特徴とする磁性体検出センサ。A magnetic substance detection sensor.
前記磁石のＮＳ方向を法線とし、前記磁石のＮＳ軸の中点よりも前記被検出媒体が接近する前記磁石の磁極と反対側の磁極側に位置する平面上に前記磁界検出素子が配置され、NS ,
前記磁性膜は前記磁性膜の磁化が磁界検出方向に揃った磁区構造を有し、The magnetic film has a magnetic domain structure in which the magnetization of the magnetic film is aligned in the magnetic field detection direction,
前記磁界検出素子は前記磁石により印加されるバイアス磁界が前記磁界検出素子の磁性膜の磁化が磁界検出方向に飽和する領域に位置している、The magnetic field detecting element is located in a region where the bias magnetic field applied by the magnet saturates the magnetization of the magnetic film of the magnetic field detecting element in the magnetic field detection direction.
ことを特徴とする磁性体検出センサ。A magnetic substance detection sensor.
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| EP08153527A EP1975637B1 (en) | 2007-03-29 | 2008-03-28 | Magnetic substance detection sensor and magnetic substance detecting apparatus |
| CN2008100879988A CN101275992B (en) | 2007-03-29 | 2008-03-28 | Magnetic substance detection sensor and magnetic substance detecting apparatus |
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