JPS59157514A - Magnetic rotation sensor - Google Patents
Magnetic rotation sensorInfo
- Publication number
- JPS59157514A JPS59157514A JP3073083A JP3073083A JPS59157514A JP S59157514 A JPS59157514 A JP S59157514A JP 3073083 A JP3073083 A JP 3073083A JP 3073083 A JP3073083 A JP 3073083A JP S59157514 A JPS59157514 A JP S59157514A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic field
- signal magnetic
- magnet
- magneto
- resistance element
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
- G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
- G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
- G01D5/142—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices
- G01D5/147—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage using Hall-effect devices influenced by the movement of a third element, the position of Hall device and the source of magnetic field being fixed in respect to each other
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
- Linear Or Angular Velocity Measurement And Their Indicating Devices (AREA)
- Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、回転体と同軸で周辺を磁化して信号磁界を発
生するドラム又はディスクと、回転体の回転に際し信号
磁界の変化を検出する磁気抵抗素子との間隙を比較的太
さくできるようにした磁性と、信号磁界やその変化を検
出する磁気抵抗素子との間には、なるべく大きな間隙を
とれることが望ましい。太ぎな間隙を許容できれば、そ
れだけ間隙が大きい磁性回転センサを提供することにあ
磁気抵抗素子を強磁性体製の基板上に設置することとし
た。すなわち第２図（ａ） Ｋ示す如く、信号磁界発生
用磁石近傍に強磁性体が存在しなければ磁石から遠（な
るＫつれ信号磁界はすぐ弱くなるが、（ｂ）に示す如く
信号磁界発生用磁石近傍にかなり厚（・強磁性体板が存
在すると、この板の内部磁路のリラクタンスは極めて小
さいから、この板にいたる磁界（磁束密度）は比較的強
くなる。すなわち、この強磁性体板は信号磁界発生用磁
石からあたかも磁束を吸い出して集めるような作用をす
る。従って強磁性体製基板上に磁気抵抗素子を設置する
ことにすれば、信号磁界を発生する回転部分と磁気抵抗
素子との間の間隙を従来よりも大きくできる。なお磁気
抵抗素子自体はガラス基板 ′上に形成した強磁性体薄
膜バタンなので、強磁性例、（ｂ）は着磁ディスクを用
（・た実施例を示す。Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a drum or disk that is coaxial with a rotating body and magnetizes the periphery to generate a signal magnetic field, and a magnetic drum or disk that detects changes in the signal magnetic field when the rotating body rotates. It is desirable to have as large a gap as possible between the magnet, which allows the gap with the resistance element to be relatively thick, and the magnetoresistive element, which detects the signal magnetic field and its changes. If a thicker gap can be tolerated, a magnetic rotation sensor with a larger gap can be provided by installing the magnetoresistive element on a substrate made of ferromagnetic material. In other words, as shown in Fig. 2 (a), if there is no ferromagnetic material near the signal magnetic field generating magnet, the signal magnetic field will become weaker as the magnet is far away (K), but as shown in (b), the signal magnetic field will not be generated. If there is a fairly thick ferromagnetic plate near the magnet, the reluctance of the internal magnetic path of this plate is extremely small, so the magnetic field (magnetic flux density) reaching this plate will be relatively strong. The plate acts as if it sucks out and collects the magnetic flux from the magnet for generating the signal magnetic field.Therefore, if you decide to install the magnetoresistive element on the ferromagnetic substrate, the rotating part that generates the signal magnetic field and the magnetoresistive element The gap between the magnetoresistive element and the magnetoresistive element itself is a thin ferromagnetic film formed on a glass substrate. shows.
本発明により間隙δを大きくでき、部品や組立の許容公
差に余裕が生じ、信頼性の高い製品が容易に得られる。According to the present invention, the gap δ can be increased, allowing more margin for tolerances in parts and assembly, and highly reliable products can be easily obtained.
なお図中Ｅと示したのは磁気抵抗素子の磁化容易軸方向
を示す。この場合の磁化容易軸は、第４図に示す如く磁
気抵抗素子バタンの形状異方性に基因する。信号磁界発
生用磁石は、磁気抵抗素子をその磁化困難軸方向に磁化
させ、センサは磁化の方向に直角な方向の電気抵抗変化
（いわゆる横効果）の検出により回転を検出している。Note that E in the figure indicates the easy axis direction of magnetization of the magnetoresistive element. The axis of easy magnetization in this case is due to the shape anisotropy of the magnetoresistive element batten, as shown in FIG. The signal magnetic field generating magnet magnetizes the magnetoresistive element in the direction of its hard magnetization axis, and the sensor detects rotation by detecting changes in electrical resistance (so-called transverse effect) in a direction perpendicular to the direction of magnetization.
磁気抵抗素子には信号磁界発生用磁石により交互に方向
の反転する磁場Ｈが加えられ、それに応じて電気抵抗に
影響する磁束密度Ｂが変化するが、周知の如（、これら
両者の関係はヒステリシスループを描き、しかも実際に
は磁場１１は単に外部の信号磁界発生用磁石によるもの
のみではな（、磁気抵抗素子自体が磁化したために牛じ
た反磁場が加わる。既述の如（、山付回転センサは横効
果を用い、磁気抵抗素子の磁化困難軸方向すなわち極め
て強大な反磁場の生ずる方向に外部磁場を加えるように
している。正しくこの様になっていれば、外部からの信
号磁場がＯの時、ＢもほとんどＯＫなるが、次に磁化さ
せる時、保磁力の影響でＨの方向によりＢの値にかなり
の差が生ずる。また外部磁界の加わる方向に対し、実際
の磁気抵抗素子の磁化困難軸の方向がわずかに傾き易い
（Ｍ造誤差などで）が、かかる場合には磁化困難軸方向
のＢ成分値が０になった時でも磁化容易軸方向のＢ成分
値が残留する。第３図（ａ）は、磁気抵抗素子の磁化困
難軸方向にほぼ治って外部磁場を印加した時の、素子の
電気抵抗変化△Ｒ／Ｒと磁場印加方向の磁化困難軸方向
からの傾きとの関係を示す。A magnetic field H whose direction is alternately reversed is applied to the magnetoresistive element by a magnet for generating a signal magnetic field, and the magnetic flux density B, which affects the electrical resistance, changes accordingly. In fact, the magnetic field 11 is generated not only by the external signal magnetic field generating magnet (but also by the fact that the magnetoresistive element itself is magnetized, so a demagnetizing field is added. The rotation sensor uses the transverse effect to apply an external magnetic field in the direction of the hard magnetization axis of the magnetoresistive element, that is, in the direction where an extremely strong demagnetizing field is generated.If this is done correctly, the signal magnetic field from the outside will be When O, B is also almost OK, but when magnetizing next time, there will be a considerable difference in the value of B depending on the direction of H due to the influence of coercive force.Also, in the direction of external magnetic field, the actual magnetoresistive element The direction of the hard magnetization axis tends to tilt slightly (due to M manufacturing errors, etc.), but in such a case, even when the B component value in the hard magnetization axis direction becomes 0, the B component value in the easy magnetization axis direction remains. Figure 3 (a) shows the electrical resistance change △R/R of the element and the inclination of the direction of magnetic field application from the direction of the hard axis of magnetization when an external magnetic field is applied after the magnetoresistive element is almost aligned in the direction of the hard axis of magnetization. Indicates the relationship between
傾・き角が０度の近辺で印加磁場方向の影響が見ら３−
れる。第３図（ｂ）は第４図に示す様に磁化容易軸方向
Ｊ／ｌ−（Ｂ ）に１〜８ガウス程度の弱いバイアス磁
界を加えた時の、図（ａ）の場合と同様な角度特性を示
す。傾き角０変哲辺の特性が平らになっている。かかる
バイアス磁界を加えるのにも、本発明に係る強磁性体製
基板を用いた場合には、わざわざ永久磁石など用いる必
要はなく、この基板を着磁すればよい。なお本発明に係
る基板用強磁性体には、ごく一般的な安価な軟鋼板ある
いは電磁軟以上説明したように本発明によれば、製造容
易で特性、ＪＭ頼付性良好磁性回転センサが得られる。The influence of the direction of the applied magnetic field can be seen near a tilt angle of 0 degrees. Figure 3 (b) shows the same situation as in Figure (a) when a weak bias magnetic field of about 1 to 8 Gauss is applied in the easy magnetization axis direction J/l-(B ) as shown in Figure 4. Shows angular characteristics. The characteristics of the irregular side with an inclination angle of 0 are flat. To apply such a bias magnetic field, when the ferromagnetic substrate according to the present invention is used, there is no need to use a permanent magnet, and the substrate can be magnetized. The ferromagnetic material for the substrate according to the present invention may be a very common inexpensive mild steel plate or an electromagnetic soft plate.As explained above, according to the present invention, a magnetic rotation sensor that is easy to manufacture and has good characteristics and JM reliability can be obtained. It will be done.
第１図（ａ）は本発明のドラム方式実施例図、同図（ｂ
）はディスク方式実施例図、第２図（ａ）、（ｂ）は本
発明の原理説明図、第３図（ａ）は磁気抵抗素子磁化困
難軸と印加磁場の傾き角が電気抵抗変化に及ぼす影響す
なわち角度特性を示す図、同図（ｂ）はバイアス磁界に
より平らになった角度特性図、第４図はバイアス磁界説
明図である。
代理人 弁理士 高 橋 明１ 夫
４−FIG. 1(a) is an embodiment of the drum system of the present invention, and FIG. 1(b)
) is a diagram of an embodiment of the disk method, Figures 2(a) and (b) are diagrams explaining the principle of the present invention, and Figure 3(a) is a diagram showing how the inclination angle of the hard magnetization axis of the magnetoresistive element and the applied magnetic field changes in electrical resistance. FIG. 4 is a diagram showing the influence, that is, the angular characteristics. FIG. 4B is a diagram showing the angular characteristics flattened by the bias magnetic field. FIG. Agent Patent Attorney Akira Takahashi 1 Husband 4-
Claims (2)
界発生手段を設け、回転体の回転に伴って生ずる信号磁
界の変化を、磁気抵抗素子の抵抗変化として検出するこ
とにより、回転体の回転を無接触で検出する磁性回転セ
ンサにおいて、強磁性体製の基板上に磁気抵抗素子を設
置したことを特徴とする磁性回転センサ。1. By providing a signal magnetic field generating means around a drum or disk coaxial with the rotating body and detecting changes in the signal magnetic field caused by the rotation of the rotating body as changes in the resistance of the magnetoresistive element, rotation of the rotating body can be eliminated. A magnetic rotation sensor that detects by contact, characterized in that a magnetic resistance element is installed on a substrate made of ferromagnetic material.
向に直交させ、かつ強磁性体基板に着磁して、磁気抵抗
素子の磁化容易軸方向にバイアス磁界を加えるようにし
た特許請求の範囲第１項記載の磁性回転センサ。2. The easy magnetization axis of the magnetoresistive element is orthogonal to the moving direction of the signal magnetic field, and the ferromagnetic substrate is magnetized to apply a bias magnetic field in the direction of the easy magnetization axis of the magnetoresistive element. The magnetic rotation sensor according to item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3073083A JPS59157514A (en) | 1983-02-28 | 1983-02-28 | Magnetic rotation sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3073083A JPS59157514A (en) | 1983-02-28 | 1983-02-28 | Magnetic rotation sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59157514A true JPS59157514A (en) | 1984-09-06 |
| JPH0480324B2 JPH0480324B2 (en) | 1992-12-18 |
Family
ID=12311779
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3073083A Granted JPS59157514A (en) | 1983-02-28 | 1983-02-28 | Magnetic rotation sensor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59157514A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6299814U (en) * | 1985-12-12 | 1987-06-25 | ||
| US5998989A (en) * | 1993-12-22 | 1999-12-07 | Itt Automotive Europe Gmbh | Device including magnet-biased magnetoresistive sensor and rotatable, magnetized encoder for detecting rotary movements |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS501712A (en) * | 1972-12-29 | 1975-01-09 | ||
| JPS5246703A (en) * | 1975-10-09 | 1977-04-13 | Matsushita Electric Ind Co Ltd | Keyboard equipment |
| JPS5260847U (en) * | 1975-10-30 | 1977-05-04 | ||
| JPS54162556A (en) * | 1978-06-13 | 1979-12-24 | Nec Corp | Angle detector |
| JPS56142409A (en) * | 1980-04-09 | 1981-11-06 | Nec Corp | Angle detector |
-
1983
- 1983-02-28 JP JP3073083A patent/JPS59157514A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS501712A (en) * | 1972-12-29 | 1975-01-09 | ||
| JPS5246703A (en) * | 1975-10-09 | 1977-04-13 | Matsushita Electric Ind Co Ltd | Keyboard equipment |
| JPS5260847U (en) * | 1975-10-30 | 1977-05-04 | ||
| JPS54162556A (en) * | 1978-06-13 | 1979-12-24 | Nec Corp | Angle detector |
| JPS56142409A (en) * | 1980-04-09 | 1981-11-06 | Nec Corp | Angle detector |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6299814U (en) * | 1985-12-12 | 1987-06-25 | ||
| US5998989A (en) * | 1993-12-22 | 1999-12-07 | Itt Automotive Europe Gmbh | Device including magnet-biased magnetoresistive sensor and rotatable, magnetized encoder for detecting rotary movements |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0480324B2 (en) | 1992-12-18 |
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