JP2001281311A - Disturbance magnetic field canceling device - Google Patents
Disturbance magnetic field canceling deviceInfo
- Publication number
- JP2001281311A JP2001281311A JP2000089476A JP2000089476A JP2001281311A JP 2001281311 A JP2001281311 A JP 2001281311A JP 2000089476 A JP2000089476 A JP 2000089476A JP 2000089476 A JP2000089476 A JP 2000089476A JP 2001281311 A JP2001281311 A JP 2001281311A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- canceling
- coil
- disturbance
- local
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Shielding Devices Or Components To Electric Or Magnetic Fields (AREA)
- Measuring Magnetic Variables (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、分析装置等が外部
からの変動磁界による悪影響を受けないように、その使
用場所において変動磁界をキャンセルするための装置に
関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for canceling a fluctuating magnetic field at a place where the analyzer is used so that the analyzing apparatus or the like is not adversely affected by an external fluctuating magnetic field.
【０００２】[0002]
【従来の技術】走査電子顕微鏡などが配置されている場
所の周辺には、車輌やエレベーター等の移動に伴う変動
磁界や配電線から生じる交流磁界など、その分析性能を
劣化させるような変動磁界の発生源が多く存在する。こ
の様な変動磁界による悪影響をなるべく少なくするた
め、従来から磁気シールドルームや外乱磁界をキャンセ
ルする装置が実用化されている。従来の外乱磁界キャン
セル装置では、図４に示すように、磁界検出器５１、増
幅器５２、減算回路５３、電流出力回路５４、外乱磁界
の打ち消し磁界用コイル５５により構成されており、走
査電子顕微鏡筒など分析装置５６の周りを前記外乱磁界
打ち消し磁界用コイル５５で囲って磁界キャンセルの領
域が形成されている。そして、その磁界キャンセル領域
内部であって分析装置５６の近傍に前記磁界検出器５１
を設置して使用されているのである。図中５７は前述し
た外乱磁界の発生源を示している。上記装置において
は、外乱磁界の発生源５７で生じた磁界は磁界検出器５
１で検知され、この磁気検知信号は増幅器５２で増幅さ
れた後、減算回路５３で地磁気等の静磁界が減算され
る。そして、それにより算出された磁界変動分が、電流
出力回路５４により外乱磁界の打ち消し磁界用コイル５
５を励磁する。磁界検出器５１の検知信号が０となるよ
うにフィードバック制御を行うように出力され、これに
より前記外乱磁界を打ち消すようになっている。2. Description of the Related Art A fluctuating magnetic field, such as a fluctuating magnetic field associated with the movement of a vehicle or an elevator, or an alternating magnetic field generated from a power distribution line, which degrades its analytical performance, is located around a place where a scanning electron microscope or the like is arranged. There are many sources. In order to minimize the adverse effect of such a fluctuating magnetic field, devices for canceling a magnetically shielded room or a disturbance magnetic field have been practically used. As shown in FIG. 4, the conventional disturbance magnetic field canceling device includes a magnetic field detector 51, an amplifier 52, a subtraction circuit 53, a current output circuit 54, and a coil 55 for canceling a disturbance magnetic field. For example, a magnetic field canceling region is formed by surrounding the analyzer 56 with the disturbance magnetic field canceling magnetic field coil 55. The magnetic field detector 51 is located inside the magnetic field canceling area and near the analyzer 56.
It is installed and used. In the figure, reference numeral 57 denotes a source of the above-mentioned disturbance magnetic field. In the above device, the magnetic field generated by the disturbance magnetic field generation source 57 is
This magnetic detection signal is amplified by an amplifier 52 and then subtracted by a subtraction circuit 53 from a static magnetic field such as terrestrial magnetism. Then, the calculated magnetic field fluctuation is applied to the coil 5 for canceling the disturbance magnetic field by the current output circuit 54.
5 is excited. An output is performed so as to perform feedback control so that the detection signal of the magnetic field detector 51 becomes 0, thereby canceling the disturbance magnetic field.
【０００３】[0003]
【発明が解決しようとする課題】ところで、前記外乱磁
界キャンセル装置にあっては、外乱磁界を打ち消すコイ
ルを円形コイルとし、コイル間隔を半径とする理想的ヘ
ルムホルツコイルにすると、走査電子顕微鏡筒などの分
析装置５６のスペース確保が狭くなって困難となる。し
かし、スペース確保のために、前記打ち消し磁界用コイ
ル５５の一方５５ａ，他方５５ｂのコイル間隔を拡張し
なければならない。その結果として発生磁界の勾配がで
きる範囲が広くなり、均一性に欠けることになる。ま
た、打ち消し磁界用コイル５５を小さくすると変動磁界
キャンセル領域は狭くなり、打ち消し磁界用コイル５５
を大きくするとコイル周辺にある他の装置に乱磁界を発
生することになる。By the way, in the disturbance magnetic field canceling device, when a coil for canceling a disturbance magnetic field is a circular coil and an ideal Helmholtz coil having a coil interval as a radius, a scanning electron microscope tube or the like is used. It becomes difficult to secure the space for the analyzer 56, which is difficult. However, in order to secure a space, the coil interval between the one 55a and the other 55b of the canceling magnetic field coil 55 must be increased. As a result, the range in which the gradient of the generated magnetic field can be widened and lacks uniformity. When the canceling magnetic field coil 55 is made smaller, the fluctuating magnetic field canceling area becomes narrower, and the canceling magnetic field coil 55 becomes smaller.
When this value is increased, a turbulent magnetic field is generated in other devices around the coil.
【０００４】ここで、磁界キャンセル装置で使用される
コイル形状は正方形が一般的であり、単独の正方形コイ
ルの中心から面に垂直に、Ｄの距離における磁界は、正
方形コイルの一辺を２Ｌ、巻線数をＮ、流す電流をＩと
すれば、次式で表される。 Ｈ＝２ＩＬ２Ｎ／（π（Ｌ２＋Ｄ２）（２Ｌ２＋Ｄ２）１／２）・・（１） （１）式から、コイルからの距離により磁界の強さ一様
ではなく、減衰していくことが分かる。図５は、対向す
る一対の打ち消し用コイルにおける磁界の強度分布を、
（１）式を基にしてグラフ化したものであって、横軸に
距離、縦軸に磁界の強さを示す。 図中の５５ａｘ，５
５ｂｘは対向する単独の打ち消し用コイルによる各打ち
消し磁界、５５ｃは打ち消し合成磁界、５７ａは外乱磁
界で理解し易いように極性を反転（負）して表示してい
る。図から磁界検出器５１の位置では、合成磁界の強さ
と外乱磁界が一致しているので外乱磁界５７ａは相殺で
きているが、分析装置５６などを置くコイル中央部の最
も重要な位置では、合成磁界５５ｃと外乱磁界５７ａと
の間に差が生じており、外乱磁界が完全に打ち消されて
いないことが分かる。[0004] Here, the coil shape used in the magnetic field canceling device is generally a square, and the magnetic field at a distance D from the center of a single square coil is 2 L on one side of the square coil. Assuming that the number of lines is N and the flowing current is I, it is expressed by the following equation. H = 2IL 2 N / (π (L 2 + D 2 ) (2L 2 + D 2 ) 1/2 ) (1) From the expression (1), the strength of the magnetic field is not uniform depending on the distance from the coil, but is attenuated. You can see that it will go. FIG. 5 shows the intensity distribution of the magnetic field in the pair of opposing canceling coils,
This is a graph based on the equation (1), in which the horizontal axis indicates the distance and the vertical axis indicates the strength of the magnetic field. 55ax, 5 in the figure
5bx is a canceling magnetic field generated by a single opposing canceling coil, 55c is a canceling composite magnetic field, and 57a is a disturbance magnetic field, and the polarity is inverted (negative) for easy understanding. From the figure, at the position of the magnetic field detector 51, the disturbance magnetic field 57a can be canceled out because the intensity of the combined magnetic field and the disturbance magnetic field coincide with each other. There is a difference between the magnetic field 55c and the disturbance magnetic field 57a, which indicates that the disturbance magnetic field is not completely canceled.
【０００５】従来の外乱磁界キャンセル装置ではこのよ
うな欠点があって、磁界検出器５１と分析装置５６との
距離が離れるほど打ち消し誤差は増大し、走査電子顕微
鏡などの装置を使用して精確な分析はできないという問
題があった。[0005] The conventional disturbance magnetic field canceling device has such a drawback. As the distance between the magnetic field detector 51 and the analyzer 56 increases, the canceling error increases, and the accuracy can be improved by using a device such as a scanning electron microscope. There was a problem that analysis was not possible.
【０００６】本発明はこのような従来の問題点を解決す
るもので、磁界検出器を走査電子顕微鏡筒など装置の重
要な中心に置くことができない場合でも外乱磁界を打ち
消し精確な分析ができ、さらに打ち消すコイルを最小限
に設置できる外乱磁界キャンセル装置を提供することを
目的とする。The present invention solves such a conventional problem. Even when the magnetic field detector cannot be placed at an important center of a device such as a scanning electron microscope tube, a disturbance magnetic field can be canceled and accurate analysis can be performed. It is still another object of the present invention to provide a disturbance magnetic field canceling device capable of minimizing a coil for canceling.
【０００７】[0007]
【課題を解決するための手段】前記目的を達成するため
の手段として、本発明請求項１記載の外乱磁界キャンセ
ル装置では、外乱磁界を打ち消す磁界を発生するための
コイルを備えた外乱磁界キャンセル装置において、前記
外乱磁界の打ち消し磁界用コイル近傍であって磁束通過
面の一部において磁界をキャンセルする局部磁界打ち消
しコイルと、前記局部磁界打ち消しコイルの磁束通過領
域内に配置される前記外乱磁界を検知する磁界検出器
と、前記磁界検出器の検知信号により前記外乱磁界の打
ち消し磁界用コイルと前記局部磁界打ち消しコイルに外
乱磁界キャンセル用電流を出力する電流出力回路と、を
有することを特徴とする。According to a first aspect of the present invention, there is provided a disturbance magnetic field canceling apparatus including a coil for generating a magnetic field for canceling a disturbance magnetic field. Detecting a local magnetic field canceling coil that cancels a magnetic field in a part of a magnetic flux passing surface in the vicinity of the disturbance magnetic field canceling magnetic field coil and the disturbance magnetic field disposed in a magnetic flux passing area of the local magnetic field canceling coil And a current output circuit that outputs a disturbance magnetic field canceling current to the disturbance magnetic field canceling coil and the local magnetic field canceling coil based on a detection signal of the magnetic field detector.
【０００８】請求項２記載の外乱磁界キャンセル装置で
は、請求項１記載の外乱磁界キャンセル装置において、
局部磁界打ち消しコイルを備えた外乱磁界の打ち消し磁
界用コイルが互いに直交する３軸の位置ごとに対を成し
て対向配置されていることを特徴とする。According to a second aspect of the present invention, there is provided a disturbance magnetic field canceling apparatus.
Disturbing magnetic field canceling magnetic field coils provided with a local magnetic field canceling coil are opposed to each other in pairs at positions of three axes orthogonal to each other.
【０００９】請求項３記載の外乱磁界キャンセル装置で
は、請求項１または請求項２記載の外乱磁界キャンセル
装置において、局部磁界打ち消しコイルが外乱磁界の打
ち消し磁界用コイルの面内に配置され、磁界検出器が局
部磁界打ち消しコイルの磁束中心位置に配置されている
ことを特徴とする。According to a third aspect of the present invention, there is provided a disturbance magnetic field canceling device according to the first or second aspect, wherein the local magnetic field canceling coil is disposed in a plane of the disturbance magnetic field canceling magnetic field coil, and the magnetic field is detected. The device is arranged at a magnetic flux center position of the local magnetic field canceling coil.
【００１０】請求項４記載の外乱磁界キャンセル装置で
は、外乱磁界を検知する磁界検出器と、この磁界検出器
と外乱磁界を打ち消す磁界を発生させるための対を成す
打ち消し磁界用コイルと、前記磁界検出器に前記打ち消
し磁界用コイルの発生磁界の影響を一部分キャンセルし
て補正する磁界を発生する局部磁界打ち消しコイルと、
前記磁界検出器よりの出力信号が供給される増幅器と、
前記増幅器の信号から静磁界成分を減算し変動磁界成分
を出力する回路と、変動磁界成分を励磁電流として出力
する電流出力回路と、前記電流出力を打ち消し磁界用コ
イルと局部磁界打ち消しコイルとに分流する分流器を備
え、外乱磁界の打ち消し磁界用コイルと局部磁界打ち消
しコイルは前記電流出力回路の出力に基づいて励磁され
るように構成されていることを特徴とする。According to a fourth aspect of the present invention, there is provided a disturbance magnetic field canceling apparatus, wherein a magnetic field detector for detecting a disturbance magnetic field, a canceling magnetic field coil forming a pair for generating a magnetic field for canceling the disturbance magnetic field and the disturbance magnetic field; A local magnetic field canceling coil that generates a magnetic field to partially cancel and correct the effect of the generated magnetic field of the canceling magnetic field coil on the detector,
An amplifier to which an output signal from the magnetic field detector is supplied;
A circuit that subtracts a static magnetic field component from the signal of the amplifier to output a fluctuating magnetic field component, a current output circuit that outputs the fluctuating magnetic field component as an exciting current, and a current shunt to cancel the current output and a local magnetic field canceling coil And a magnetic field canceling coil for disturbing magnetic field and a local magnetic field canceling coil are configured to be excited based on an output of the current output circuit.
【００１１】[0011]
【作用】本発明の外乱磁界キャンセル装置では、外乱磁
界を検出する磁界検出器を外乱磁界の打ち消し磁界用コ
イル近傍であって磁束通過領域の一部において磁界をキ
ャンセルする局部磁界打ち消しコイルの磁束通過領域内
に配置したので、磁界検出器は静磁界成分と変動磁界成
分を検出する。そこで検出信号成分から変動磁界成分だ
けを抽出し、その値を基にしてリアルタイムで打ち消し
磁界用電流と磁界レベル補正のための局部磁界打ち消し
用電流を各コイルに流すことにより、判定装置などが設
置される真に必要な位置での外乱磁界を良好にキャンセ
ルし、走査電子顕微鏡筒などによる判定を極めて精確に
行うことができるようになる。また、余分に強力なキャ
ンセル用磁界を必要としないので、外乱磁界の打ち消し
磁界用コイルを小型化でき、使用場所や装置の大きさ等
に限定されることなく使用することができる。In the disturbance magnetic field canceling device according to the present invention, the magnetic field detector for detecting the disturbance magnetic field passes through the local magnetic field canceling coil which cancels the magnetic field in a part of the magnetic flux passage area near the disturbance magnetic field canceling coil. Since the magnetic field detector is disposed in the region, the magnetic field detector detects a static magnetic field component and a fluctuating magnetic field component. Therefore, only the fluctuating magnetic field component is extracted from the detection signal component, and based on the value, the judgment device is installed by passing the current for the canceling magnetic field and the local magnetic field canceling current for correcting the magnetic field level in each coil in real time. The disturbance magnetic field at the truly required position can be satisfactorily canceled, and the determination by the scanning electron microscope tube or the like can be made extremely accurately. In addition, since an extra strong canceling magnetic field is not required, the size of the coil for canceling the disturbance magnetic field can be reduced, and the coil can be used without being limited by the place of use or the size of the device.
【００１２】[0012]
【発明の実施の形態】以下、本発明の実施の形態を図面
に基づいて詳細に説明する。図１は実施の形態の外乱磁
界キャンセル装置を示す模式図、図２は同上の使用状態
を示す斜視図、図３は同上の装置内発生磁界を示すグラ
フ図である。Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a disturbance magnetic field canceling device according to an embodiment, FIG. 2 is a perspective view showing a use state of the above, and FIG. 3 is a graph showing a magnetic field generated inside the device.
【００１３】まず、実施の形態の構成を説明する。本実
施の形態の外乱磁界キャンセル装置は、磁界検出器ｘ
１，ｙ１，ｚ１、増幅器ｘ２，ｙ２，ｚ２、減算回路ｘ
３，ｙ３，ｚ３、電流出力回路ｘ４，ｙ４，ｚ４、分流
器ｘ５，ｙ５，ｚ５、外乱磁界の打ち消し磁界用コイル
ｘ６，ｙ６，ｚ６、局部磁界打ち消しコイルｘ７，ｙ
７，ｚ７を主要な構成としている。図中８は外乱磁界発
生源、９は走査電子顕微鏡筒などの判定装置である。First, the configuration of the embodiment will be described. The disturbance magnetic field canceling device of the present embodiment includes a magnetic field detector x
1, y1, z1, amplifiers x2, y2, z2, subtraction circuit x
3, y3, z3, current output circuits x4, y4, z4, shunts x5, y5, z5, disturbance magnetic field canceling magnetic field coils x6, y6, z6, local magnetic field canceling coils x7, y
7, z7 are the main components. In the figure, reference numeral 8 denotes a disturbance magnetic field generation source, and 9 denotes a determination device such as a scanning electron microscope tube.
【００１４】前記磁界検出器ｘ１は従来と同様に、ホー
ル素子や磁気抵抗素子等の磁界を検知する素子やフラッ
クスゲートセンサのような磁気検知回路を使用してお
り、外乱発生源８で発生した変動磁界を検知するもので
ある。増幅器ｘ２は、磁界検出器ｘ１の検知信号を増幅
するものであり、減算回路ｘ３は、増幅器ｘ２の出力か
ら地磁気等の静磁界成分を減算し変動磁界成分を算出す
るものである。電流出力回路ｘ４は、前記変動磁界成分
のみに比例した電流出力を行うものであり、分流器ｘ５
は、前記出力電流を外乱磁界の打ち消し磁界用コイルｘ
６と磁界レベル補正のための局部磁界打ち消しコイルｘ
７に分流するものである。外乱磁界の打ち消し磁界用コ
イルｘ６，ｙ６，ｚ６は、前記判定装置９を囲繞するよ
うにそれぞれ三軸上に一対づつ対向配置され、内部に磁
界キャンセルの領域を形成するものである。局部磁界打
ち消しコイルｘ７〜ｚ７は、それぞれ前記外乱磁界の打
ち消し磁界用コイルｘ６〜ｚ６の面内中心位置に配置さ
れ、更に、それぞれその中心位置に、前記磁界検出器ｘ
１〜ｚ１を配置させるものである。尚、ｙ２〜ｙ５，ｚ
２〜ｚ５も前記と同様の構成であるので、その説明は省
略する。The magnetic field detector x1 uses an element for detecting a magnetic field, such as a Hall element or a magnetoresistive element, or a magnetic detection circuit such as a flux gate sensor, as in the prior art. It detects a fluctuating magnetic field. The amplifier x2 amplifies the detection signal of the magnetic field detector x1, and the subtraction circuit x3 calculates a fluctuating magnetic field component by subtracting a static magnetic field component such as terrestrial magnetism from the output of the amplifier x2. The current output circuit x4 outputs a current proportional to only the fluctuating magnetic field component.
The output current is a coil x for canceling a disturbance magnetic field.
6 and a local magnetic field canceling coil x for magnetic field level correction
7. The coils x6, y6, and z6 for canceling the disturbance magnetic field are arranged in pairs on three axes so as to surround the determination device 9, and form a magnetic field canceling region therein. The local magnetic field canceling coils x7 to z7 are respectively arranged at the in-plane center positions of the disturbance magnetic field canceling magnetic field coils x6 to z6, and the magnetic field detector x is located at the center position.
1 to z1. Note that y2 to y5, z
2 to z5 have the same configuration as described above, and a description thereof will be omitted.
【００１５】次に作用を説明する。磁界検出器ｘ１によ
り、外乱発生源８で発生した変動磁界成分の磁界を検出
し電流出力回路ｘ４で励磁電流として発生させるのだ
が、従来装置との違いはここから生じてくる。まず、図
３は、本発明装置内で発生する磁界の強さを横軸に距離
を取って表示したものである。図中のｘ６ａ，ｘ６ｂ
は、（１）式に基づいて発生する外乱磁界の打ち消し磁
界用コイルｘ６の一方６ａと他方６ｂによる磁界を示
す。また、ａ１は前記磁界ｘ６ａ，ｘ６ｂによるキャン
セル用合成磁界、ｂ１は外乱磁界である。ｃ１は局部磁
界打ち消しコイル７の局部キャンセル用磁界、ｄ１はキ
ャンセル用合成磁界ａ１と逆極性の局部キャンセル用磁
界ｃ１の合成磁界を示す。Next, the operation will be described. The magnetic field detector x1 detects the magnetic field of the fluctuating magnetic field component generated in the disturbance generating source 8 and generates it as an exciting current in the current output circuit x4. However, the difference from the conventional device arises from this. First, FIG. 3 shows the intensity of the magnetic field generated in the apparatus of the present invention, with the horizontal axis indicating the distance. X6a, x6b in the figure
Indicates a magnetic field generated by one of the coils 6a and the other 6b of the coil x6 for canceling the disturbance magnetic field generated based on the equation (1). A1 is a combined magnetic field for cancellation by the magnetic fields x6a and x6b, and b1 is a disturbance magnetic field. c1 indicates a local canceling magnetic field of the local magnetic field canceling coil 7, and d1 indicates a synthetic magnetic field of the local canceling magnetic field c1 having the opposite polarity to the canceling synthetic magnetic field a1.
【００１６】図のｃ１は、円形コイルの中心に磁界検出
器ｘ１を配置した事例であって、次式（２）に基づいて
発生する磁界であって、コイル径が小さいと、磁界の強
さはコイルから離れるに従い急激に減少するので、局部
キャンセル用磁界ｃ１の影響は外乱磁界の打ち消し磁界
用コイルｘ６の一方６ａと他方６ｂとの中央部まで及ば
ない。 Ｈ＝ｒ２・Ｎ・Ｉ／２（ｒ２＋Ｄ２）３／２ ・・・（２） ただし、ｒはコイルの径、Ｎは巻数、Ｉは電流、Ｄはコ
イルの中心から面に垂直に離れた距離である。そこで、
磁界検出器ｘ１が設置されているコイル位置Ａ点におい
て、打ち消し磁界用コイルｘ６が発生する磁界ｘ６ａ，
ｘ６ｂの合成磁界ａ１を打ち消すように、局部磁界打ち
消しコイルｘ７に電流を流せば、コイル位置近傍におけ
る磁界の強度分布は曲線ｄ１となり、Ａ点では打ち消し
磁界用コイルｘ６が発生する磁界の影響を受けなくな
り、外乱磁界キャンセル性能は著しく改善される。FIG. 1C shows an example in which the magnetic field detector x1 is arranged at the center of a circular coil. The magnetic field is generated based on the following equation (2). Rapidly decreases as the distance from the coil increases, so that the influence of the local canceling magnetic field c1 does not reach the central portion between the one 6a and the other 6b of the disturbance magnetic field canceling coil x6. H = r 2 · N · I / 2 (r 2 + D 2 ) 3/2 (2) where r is the diameter of the coil, N is the number of turns, I is the current, and D is perpendicular to the plane from the center of the coil. It is a distance away. Therefore,
At a coil position A where the magnetic field detector x1 is installed, a magnetic field x6a, generated by the canceling magnetic field coil x6,
If a current is applied to the local magnetic field canceling coil x7 so as to cancel the synthetic magnetic field a1 of x6b, the magnetic field intensity distribution near the coil position becomes a curve d1, and the point A is affected by the magnetic field generated by the canceling magnetic field coil x6. As a result, the disturbance magnetic field canceling performance is significantly improved.
【００１７】具体的にはそのために、外乱磁界の打ち消
し磁界用コイルｘ６に流す電流出力回路４の励磁電流
を、分流器ｘ５で局部磁界打ち消しコイルｘ７に分流
し、相互のコイルに同様な比率で励磁電流を流す。その
結果、変動する外乱磁界は打ち消し磁界用コイルｘ６が
発生する磁界でキャンセルすると同時に、Ａ点にその影
響が現れなくする。結局のところ、磁界検出器ｘ１は、
外乱磁界の打ち消し磁界用コイルで発生した磁界に影響
されることなく、外乱磁界の静磁界成分と変動磁界成分
を検出し、その検出信号を増幅器ｘ２で増幅し、減算回
路ｘ３で静磁界成分を減算し、電流出力回路ｘ４から変
動分だけの出力電流を分流器ｘ５を介して局部磁界打ち
消しコイルｘ７と打ち消し磁界用コイルｘ６に分流する
ことにより、外乱磁界を精度良くキャンセルすることが
できるのである。尚、これまでの説明はｘ軸成分にのみ
着目して記載してきたが、ｙ軸成分、ｚ軸成分について
も同様の構成、機能であるので、その説明を省略する。
図中、外乱磁界の打ち消し磁界用コイルｙ６とｚ６につ
いてその一方と他方を区別する符号は省略している。ま
た、各コイルの形状は、正方形、長方形、円形以外にソ
レノイド形状であっても本発明の目的が達成できるもの
であれば、その形状に限定されるものではない。Specifically, for this purpose, the exciting current of the current output circuit 4, which flows through the disturbance magnetic field canceling magnetic field coil x6, is shunted to the local magnetic field canceling coil x7 by the shunt x5, and is applied to the mutual coils at the same ratio. Excitation current is applied. As a result, the fluctuating disturbance magnetic field is canceled by the magnetic field generated by the canceling magnetic field coil x6, and at the same time its influence does not appear at the point A. After all, the magnetic field detector x1 is
The static magnetic field component and the fluctuating magnetic field component of the disturbance magnetic field are detected without being affected by the magnetic field generated by the disturbance magnetic field canceling magnetic field coil, the detection signal is amplified by the amplifier x2, and the subtraction circuit x3 is used to reduce the static magnetic field component. The disturbance magnetic field can be canceled with high accuracy by subtracting and diverting the output current corresponding to the variation from the current output circuit x4 to the local magnetic field canceling coil x7 and the canceling magnetic field coil x6 via the shunt x5. . Although the description so far has focused on only the x-axis component, the y-axis component and the z-axis component have the same configuration and function, and a description thereof will be omitted.
In the drawing, reference numerals for distinguishing one from the other are omitted for coils y6 and z6 for canceling a disturbance magnetic field. The shape of each coil is not limited to a square, a rectangle, or a circle, as long as the object of the present invention can be achieved, as long as the object of the present invention can be achieved.
【００１８】以上、説明してきたように本実施の形態の
外乱磁界キャンセル装置にあっては、磁界検出器１は静
磁界成分と変動磁界成分の磁界検出だけとなるので、変
動磁界成分だけを抽出しその値によってリアルタイムで
各コイルを励磁することにより、真に必要な位置での外
乱磁界を良好にキャンセルし、走査電子顕微鏡筒９など
による判定を極めて精確に行うことができる。また、余
分に強力なキャンセル用磁界を必要としないので、外乱
磁界の打ち消し磁界用コイルを小型化でき、使用場所や
装置の大きさ等に限定されることなく使用することがで
きる。As described above, in the disturbance magnetic field canceling apparatus according to the present embodiment, the magnetic field detector 1 detects only the magnetic field of the static magnetic field component and the variable magnetic field component. By exciting each coil in real time based on the value, the disturbance magnetic field at a truly necessary position can be canceled well, and the determination by the scanning electron microscope tube 9 or the like can be made extremely accurately. In addition, since an extra strong canceling magnetic field is not required, the size of the coil for canceling the disturbance magnetic field can be reduced, and the coil can be used without being limited by the place of use or the size of the device.
【００１９】以上、本発明の実施の形態を説明してきた
が、本発明の具体的な構成はこの実施の形態に限定され
るものではなく、発明の要旨を逸脱しない範囲の設計変
更等があっても本発明に含まれる。Although the embodiment of the present invention has been described above, the specific configuration of the present invention is not limited to this embodiment, and there are design changes and the like within a range not departing from the gist of the invention. This is also included in the present invention.
【００２０】[0020]
【発明の効果】以上、説明してきたように本発明の外乱
磁界キャンセル装置にあっては、前記構成としたため、
打ち消し磁界用コイル間隔内側に磁界検出器を設置しな
いでも要部の外乱磁界を精確に検知することができ、極
めて精確な判定などの作業を行うことができる。また、
打ち消し磁界用コイルを最小限に小さく構成して設置す
ることができる。そのため、外部装置に及ぼす悪影響を
減少させることができる。更に、コイル間隔の内部に磁
界検出器を置く必要がないため、乱磁界発生源を逆に打
ち消し磁界用コイルで囲み、外部装置に及ぼす乱磁界の
悪影響を減少させることもできる。As described above, the disturbance magnetic field canceling device of the present invention has the above-described configuration.
Even if a magnetic field detector is not installed inside the canceling magnetic field coil interval, a disturbance magnetic field of a main part can be accurately detected, and extremely accurate determination and other operations can be performed. Also,
The coil for the canceling magnetic field can be configured and installed to a minimum size. Therefore, adverse effects on the external device can be reduced. Further, since it is not necessary to dispose a magnetic field detector inside the coil interval, the source of the turbulent magnetic field can be reversed and surrounded by the coil for the magnetic field, thereby reducing the adverse effect of the turbulent magnetic field on the external device.
【図１】本発明実施の形態の外乱磁界キャンセル装置を
示す模式図である。FIG. 1 is a schematic diagram showing a disturbance magnetic field canceling device according to an embodiment of the present invention.
【図２】実施の形態の使用状態を示す斜視図である。FIG. 2 is a perspective view showing a use state of the embodiment.
【図３】実施の形態の装置内発生磁界を示すグラフ図で
ある。FIG. 3 is a graph showing a magnetic field generated in the device according to the embodiment;
【図４】従来の外乱磁界キャンセル装置を示す説明図で
ある。FIG. 4 is an explanatory diagram showing a conventional disturbance magnetic field canceling device.
【図５】従来の磁界の作用を示す説明図である。FIG. 5 is an explanatory diagram showing the action of a conventional magnetic field.
ｘ１，ｙ１，ｚ１ 磁界検出器 ｘ２，ｙ２，ｚ２ 増幅器 ｘ３，ｙ３，ｚ３ 減算回路 ｘ４，ｙ４，ｚ４ 電流出力回路 ｘ５，ｙ５，ｚ５ 分流器 ｘ６，ｙ６，ｚ６ 外乱磁界の打ち消し磁界用コイル ｘ７，ｙ７，ｚ７ 局部磁界打ち消しコイル ８ 外乱磁界発生源 ９ 判定装置 x1, y1, z1 Magnetic field detector x2, y2, z2 Amplifier x3, y3, z3 Subtraction circuit x4, y4, z4 Current output circuit x5, y5, z5 Current shunt x6, y6, z6 Disturbance magnetic field canceling coil x7, y7, z7 Local magnetic field canceling coil 8 Disturbance magnetic field source 9 Judgment device
Claims (4)
のコイルを備えた外乱磁界キャンセル装置において、 前記外乱磁界の打ち消し磁界用コイル近傍であって磁束
通過面の一部において磁界をキャンセルする局部磁界打
ち消しコイルと、 前記局部磁界打ち消しコイルの磁束通過領域内に配置さ
れる前記外乱磁界を検知する磁界検出器と、 前記磁界検出器の検知信号により前記外乱磁界の打ち消
し磁界用コイルと前記局部磁界打ち消しコイルに外乱磁
界キャンセル用電流を出力する電流出力回路と、を有す
ることを特徴とする外乱磁界キャンセル装置。1. A disturbance magnetic field canceling device comprising a coil for generating a magnetic field for canceling a disturbance magnetic field, wherein a local magnetic field cancels the magnetic field at a part of a magnetic flux passage surface near the disturbance magnetic field canceling coil. A canceling coil, a magnetic field detector for detecting the disturbing magnetic field arranged in a magnetic flux passage area of the local magnetic field canceling coil, a canceling magnetic field canceling magnetic field coil and the local magnetic field canceling by the detection signal of the magnetic field detector. A disturbance magnetic field canceling device, comprising: a current output circuit that outputs a disturbance magnetic field canceling current to a coil.
界の打ち消し磁界用コイルが互いに直交する３軸の位置
ごとに対を成して対向配置されていることを特徴とする
請求項１記載の外乱磁界キャンセル装置。2. The disturbance according to claim 1, wherein the coils for canceling the disturbance magnetic field provided with the local magnetic field canceling coils are arranged in pairs at every three axes orthogonal to each other. Magnetic field cancellation device.
ち消し磁界用コイルの面内に配置され、磁界検出器が局
部磁界打ち消しコイルの磁束中心位置に配置されている
ことを特徴とする請求項１または請求項２記載の外乱磁
界キャンセル装置。3. The local magnetic field canceling coil is arranged in the plane of the disturbance magnetic field canceling magnetic field coil, and the magnetic field detector is arranged at a magnetic flux center position of the local magnetic field canceling coil. The disturbance magnetic field canceling device according to claim 2.
磁界検出器と外乱磁界を打ち消す磁界を発生させるため
の対を成す打ち消し磁界用コイルと、前記磁界検出器に
前記打ち消し磁界用コイルの発生磁界の影響を一部分キ
ャンセルして補正する磁界を発生する局部磁界打ち消し
コイルと、前記磁界検出器よりの出力信号が供給される
増幅器と、前記増幅器の信号から静磁界成分を減算し変
動磁界成分を出力する回路と、変動磁界成分を励磁電流
として出力する電流出力回路と、前記電流出力を打ち消
し磁界用コイルと局部磁界打ち消しコイルとに分流する
分流器を備え、外乱磁界の打ち消し磁界用コイルと局部
磁界打ち消しコイルは前記電流出力回路の出力に基づい
て励磁されるように構成されていることを特徴とする外
乱磁界キャンセル装置。4. A magnetic field detector for detecting a disturbance magnetic field, a canceling magnetic field coil forming a pair for generating a magnetic field for canceling the disturbance magnetic field and the magnetic field detector, and a canceling magnetic field coil provided in the magnetic field detector. A local magnetic field canceling coil that generates a magnetic field that partially cancels and corrects the effect of the generated magnetic field, an amplifier to which an output signal from the magnetic field detector is supplied, and a variable magnetic field component that subtracts a static magnetic field component from the signal of the amplifier. A current output circuit that outputs a fluctuating magnetic field component as an exciting current, and a shunt that shunts the current output to a magnetic field canceling coil and a local magnetic field canceling coil, and a disturbance magnetic field canceling magnetic field coil. A local magnetic field canceling coil is configured to be excited based on an output of the current output circuit, Place.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000089476A JP3406273B2 (en) | 2000-03-28 | 2000-03-28 | Disturbance magnetic field cancellation device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2000089476A JP3406273B2 (en) | 2000-03-28 | 2000-03-28 | Disturbance magnetic field cancellation device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2001281311A true JP2001281311A (en) | 2001-10-10 |
| JP3406273B2 JP3406273B2 (en) | 2003-05-12 |
Family
ID=18605231
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2000089476A Expired - Fee Related JP3406273B2 (en) | 2000-03-28 | 2000-03-28 | Disturbance magnetic field cancellation device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3406273B2 (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005252254A (en) * | 2004-03-03 | 2005-09-15 | Ims Nanofabrication Gmbh | Method for compensating magnetic field in operating area |
| JP2012033669A (en) * | 2010-07-30 | 2012-02-16 | Kajima Corp | Method and system for active magnetic shield of disturbed and fluctuated magnetic field |
| JP2012115424A (en) * | 2010-11-30 | 2012-06-21 | Hitachi Metals Ltd | Disturbance magnetic field reducing device and magnetic resonance imaging apparatus |
| JP2015176243A (en) * | 2014-03-13 | 2015-10-05 | 株式会社東芝 | Paper sheet processor |
| CN106353606A (en) * | 2016-11-18 | 2017-01-25 | 中国电子科技集团公司第四十研究所 | Device and method for omnidirectional detection of power-frequency electromagnetic field |
| JP2021006813A (en) * | 2018-08-22 | 2021-01-21 | 旭化成エレクトロニクス株式会社 | Magnetic field measuring device, magnetic field measuring method and magnetic field measuring program |
| WO2023151327A1 (en) * | 2022-02-11 | 2023-08-17 | 华为技术有限公司 | Magnetic shielding device and electron beam detection device |
| US11927646B2 (en) | 2018-12-26 | 2024-03-12 | Asahi Kasei Microdevices Corporation | Magnetic field measuring apparatus |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4838972A (en) * | 1971-09-15 | 1973-06-08 | ||
| JPS5925726A (en) * | 1982-07-31 | 1984-02-09 | 株式会社島津製作所 | Diagnostic observation apparatus |
| JPH04357481A (en) * | 1991-05-13 | 1992-12-10 | Hoxan Corp | Device for eliminating magnetic noise using squid |
| JP2000037362A (en) * | 1998-07-21 | 2000-02-08 | Toshiba Corp | Device for removing environment noise magnetic field |
-
2000
- 2000-03-28 JP JP2000089476A patent/JP3406273B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4838972A (en) * | 1971-09-15 | 1973-06-08 | ||
| JPS5925726A (en) * | 1982-07-31 | 1984-02-09 | 株式会社島津製作所 | Diagnostic observation apparatus |
| JPH04357481A (en) * | 1991-05-13 | 1992-12-10 | Hoxan Corp | Device for eliminating magnetic noise using squid |
| JP2000037362A (en) * | 1998-07-21 | 2000-02-08 | Toshiba Corp | Device for removing environment noise magnetic field |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005252254A (en) * | 2004-03-03 | 2005-09-15 | Ims Nanofabrication Gmbh | Method for compensating magnetic field in operating area |
| JP2012033669A (en) * | 2010-07-30 | 2012-02-16 | Kajima Corp | Method and system for active magnetic shield of disturbed and fluctuated magnetic field |
| JP2012115424A (en) * | 2010-11-30 | 2012-06-21 | Hitachi Metals Ltd | Disturbance magnetic field reducing device and magnetic resonance imaging apparatus |
| JP2015176243A (en) * | 2014-03-13 | 2015-10-05 | 株式会社東芝 | Paper sheet processor |
| CN106353606A (en) * | 2016-11-18 | 2017-01-25 | 中国电子科技集团公司第四十研究所 | Device and method for omnidirectional detection of power-frequency electromagnetic field |
| JP2021006813A (en) * | 2018-08-22 | 2021-01-21 | 旭化成エレクトロニクス株式会社 | Magnetic field measuring device, magnetic field measuring method and magnetic field measuring program |
| JP7402768B2 (en) | 2018-08-22 | 2023-12-21 | 旭化成エレクトロニクス株式会社 | Magnetic field measurement device, magnetic field measurement method, magnetic field measurement program |
| US11927646B2 (en) | 2018-12-26 | 2024-03-12 | Asahi Kasei Microdevices Corporation | Magnetic field measuring apparatus |
| WO2023151327A1 (en) * | 2022-02-11 | 2023-08-17 | 华为技术有限公司 | Magnetic shielding device and electron beam detection device |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3406273B2 (en) | 2003-05-12 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6060278B2 (en) | Apparatus and method for detecting internal defects in steel sheet | |
| JP5531215B2 (en) | Current sensor | |
| US9958514B2 (en) | Magnetic field measurement apparatus, magnetic field measurement system and magnetic field measurement method | |
| US20130300401A1 (en) | Sensor Apparatus, in Particular Metal Sensor, with a Field-Compensated Magnetic Field Sensor | |
| JP5535467B2 (en) | Phase correction type active magnetic shield device | |
| JP2007501379A (en) | Integrated 1 / f noise removal method of magnetoresistive nanoparticle sensor | |
| JP2009210406A (en) | Current sensor and watthour meter | |
| JP2015102513A (en) | Metallic foreign matter detection device, and eddy current flaw detector | |
| JP2001281311A (en) | Disturbance magnetic field canceling device | |
| JP3884243B2 (en) | External magnetic field measurement method, static magnetic field correction method, external magnetic field measurement apparatus, and MRI apparatus | |
| JP2013217690A (en) | Magnetic field correction device and magnetic field measuring device | |
| WO2012046547A1 (en) | Current sensor | |
| JP4933122B2 (en) | Nuclear magnetic resonance probe | |
| CN110687339B (en) | Current sensor | |
| JP2013186053A (en) | Magnetic inspection system for magnetic sensors | |
| JP6097906B2 (en) | Inspection device for minute magnetic metal foreign matter | |
| JP6248201B2 (en) | Steel plate defect inspection apparatus and method | |
| JPH07209336A (en) | Current sensor | |
| JP2003273565A (en) | Active magnetic shield device | |
| JP6015518B2 (en) | Magnetic property measuring method and apparatus | |
| Ripka et al. | A 3-phase current transducer based on microfluxgate sensors | |
| JPH0325375A (en) | Eddy current measuring instrument | |
| JPH0815229A (en) | High resolution eddy current flaw detector | |
| JP2007108164A (en) | Magnetic substance sensor and magnetic substance sensor unit | |
| JP3759934B2 (en) | Magnetic sensor placement method and active magnetic shield device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| TRDD | Decision of grant or rejection written | ||
| R150 | Certificate of patent or registration of utility model |
Ref document number: 3406273 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090307 Year of fee payment: 6 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090307 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100307 Year of fee payment: 7 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100307 Year of fee payment: 7 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20110307 Year of fee payment: 8 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120307 Year of fee payment: 9 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120307 Year of fee payment: 9 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130307 Year of fee payment: 10 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20140307 Year of fee payment: 11 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313113 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |