JPS61161418A - Magnetic encoder - Google Patents
Magnetic encoderInfo
- Publication number
- JPS61161418A JPS61161418A JP60002099A JP209985A JPS61161418A JP S61161418 A JPS61161418 A JP S61161418A JP 60002099 A JP60002099 A JP 60002099A JP 209985 A JP209985 A JP 209985A JP S61161418 A JPS61161418 A JP S61161418A
- Authority
- JP
- Japan
- Prior art keywords
- permanent magnet
- pitch
- sensor
- lambdamr
- lambdap
- 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.)
- Pending
Links
- 238000001514 detection method Methods 0.000 claims description 10
- 230000005415 magnetization Effects 0.000 claims description 8
- 230000002093 peripheral effect Effects 0.000 abstract 1
- 238000010586 diagram Methods 0.000 description 29
- 230000004907 flux Effects 0.000 description 13
- 238000007493 shaping process Methods 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000004020 conductor Substances 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 230000005389 magnetism Effects 0.000 description 2
- 230000035945 sensitivity Effects 0.000 description 2
- 239000008186 active pharmaceutical agent Substances 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 210000004761 scalp Anatomy 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
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- Hall/Mr Elements (AREA)
- Transmission And Conversion Of Sensor Element Output (AREA)
Abstract
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は、移動体の移動量を磁気的、に検出して電気信
号出力を得る磁気エンコーダ、さらに詳述すれば、電気
抵抗が磁界強度に応じて変化する磁気抵抗素子の８個Ａ
ｔ ＋ Ｂｌ ＋ Ａｌｌ ＋ Ｂｇｙ ＡＳ ＋
”３ｔＡ４＋Ｂ４をこの順に夫々の間のピンチがλＭ
Ｒとなるように配設しｐ ＡｌとＡ４を＋ Ａｌｌ
とＡ、を＋ＢｌｌとＢ８を＋ＥｌとＢ４を夫々直列接続
した４回路を並列接続して得る回路に一定電圧を印加し
＋ ＡＩとＡ４の中間接続点ＡＯＩ ＋ ＡＱとＡ
８の中間接続点ＡＱ２＋Ｂ２とＢ♂の中間接続点ＢＯＱ
＋ ＢｌとＢ４の中間接続点Ｂｏｌを電圧検出端子と
する磁気抵抗センサを。[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a magnetic encoder that magnetically detects the amount of movement of a moving object and outputs an electrical signal, and more specifically, to a magnetic encoder that magnetically detects the amount of movement of a moving body and outputs an electrical signal. 8 pieces A of magnetoresistive elements that change accordingly
t + Bl + All + Bgy AS +
``3tA4+B4 in this order, the pinch between each is λM
Arrange so that R and p Al and A4 + All
A constant voltage is applied to a circuit obtained by connecting four circuits in parallel with + Bll and B8 + El and B4 connected in series, + intermediate connection point AOI between AI and A4 + AQ and A
8 intermediate connection point AQ2+B2 and B♂ intermediate connection point BOQ
+ A magnetoresistive sensor whose voltage detection terminal is the intermediate connection point Bol between Bl and B4.
Ｎ及びＳの磁極がＡ１のピッチで交互に着磁された永久
磁石に対して空隙を介して対向配置することで上記永久
磁石の移動量に応じた電圧信号を上記電圧検出端子より
得る８素子形の磁気エンコーダに関するもので２例えば
、電動機速度制御の際の回転子の位置検出用として、あ
るいは、ロボットやＶＴＲ（ビデオ・テープ・レコーダ
）等の制御用検出部に利用することができる。8 elements that obtain a voltage signal from the voltage detection terminal according to the amount of movement of the permanent magnet by arranging them with an air gap between them to face a permanent magnet in which N and S magnetic poles are alternately magnetized with a pitch of A1; For example, it can be used to detect the position of a rotor when controlling the speed of a motor, or as a detection unit for controlling robots, VTRs (video tape recorders), etc.
鉄あるいはニッケル等の磁性材料及びその合金の薄膜で
形成した導電体にその電流通過方向と直角に磁界を加え
ると、第１図実線曲線に示すように、導電体の電気抵抗
値が減少することが知られており、磁気抵抗効果と呼ば
れ、磁界の測定７位置の検出装置等に利用されている。When a magnetic field is applied to a conductor made of a thin film of a magnetic material such as iron or nickel or its alloy at right angles to the current passing direction, the electrical resistance of the conductor decreases, as shown by the solid curve in Figure 1. This effect is known as the magnetoresistive effect, and is used in seven-position detection devices for measuring magnetic fields.
なお、破線曲線は導電体にバイアス用磁石を並置した場
合の関係曲線である。Note that the broken line curve is a relationship curve when a bias magnet is placed side by side with a conductor.
この磁気抵抗効果を利用して回転体の位置検出を行なう
磁気エンコーダが実用されており、その従来例を第５図
に示す。これは、電動機の回転子の回転移動量に応じた
電気信号を得ようとする例で、第５図ら）は磁気エンコ
ーダとその周辺部分の側面図とそのｘ−ｘ断面図を示し
、１は電動機。A magnetic encoder that detects the position of a rotating body by utilizing this magnetoresistive effect is in practical use, and a conventional example thereof is shown in FIG. This is an example of trying to obtain an electrical signal according to the amount of rotational movement of the rotor of an electric motor. Figures 5 and 5) show a side view of the magnetic encoder and its surroundings, and a cross-sectional view along the line xx, Electric motor.
２は回転子軸、３はその外周に多数のＮ極、Ｓ極に着磁
された永久磁石を備えて回転子軸２と一体的に０回転す
る永久磁石回転体、４が磁気抵抗効果素子（以下、磁気
抵抗素子と称す）で構成した磁気抵抗センサ（以下、Ｍ
ＲＲセンサ称す）、５はカバーである。永久磁石回転体
３の永久磁石とＭＲＲセンサとが空隙を介して対向配設
され２回転軸２の回転位置をＭＲＲセンサにより検出す
る構成となっている。2 is a rotor shaft, 3 is a permanent magnet rotating body that has a large number of permanent magnets magnetized to N and S poles on its outer periphery and rotates 0 times integrally with the rotor shaft 2, and 4 is a magnetoresistive element. (hereinafter referred to as magnetoresistive element) composed of a magnetoresistive sensor (hereinafter referred to as M
RR sensor), 5 is a cover. The permanent magnet of the permanent magnet rotating body 3 and the MRR sensor are arranged to face each other with a gap in between, and the rotational position of the two-rotation shaft 2 is detected by the MRR sensor.
凧センサ４と永久磁石回転体３の永久磁石との関係は、
第５図（ｂ）に示すように、 ＭＲＲセンサには４個の
磁気抵抗素子Ａ ＋ ＋ ４ ＋ Ｂ ＋ ！ Ｂ
ｑがＡ１とＡ２間のビノチカゝλＭＲＩ ＢｌとＢ２間
のピッチも’ＭＲＩかつＢ、がＡ、とＡ、２間の中央位
置となるように配設され、各素子は第５図（ａ）に示す
電気回路を形成している。即ちＩ ＡＨとＡ２の直列
接続回路とｔＥｌとＢ２の直列接続回路とな°並列接続
した回路に一定電圧Ｖ。を印加し、Ａ１とＡ２の中間接
続点Ａ及びＢ１とＢ２の中間接続点Ｂを電圧検出端子と
するものである。また、 ＭＲＲセンサの永久磁石回転
体３と対向しな（・面にはバイアス用磁石６が配置され
ている。バイアス用磁石６は皿センサ４に固着されてお
り、磁性が一定（図示例ではＮ極）の磁界を常にＭＲＲ
センサに作用させるようになっているので。The relationship between the kite sensor 4 and the permanent magnet of the permanent magnet rotating body 3 is as follows:
As shown in FIG. 5(b), the MRR sensor includes four magnetoresistive elements A + + 4 + B + ! B
The pitch between Bl and B2 is also arranged so that q is the pitch between A1 and A2. The electric circuit shown in is formed. In other words, a constant voltage V is applied to the circuits connected in parallel, such as a series connection circuit of IAH and A2 and a series connection circuit of tEl and B2. is applied, and the intermediate connection point A between A1 and A2 and the intermediate connection point B between B1 and B2 are used as voltage detection terminals. In addition, a bias magnet 6 is arranged on the surface facing the permanent magnet rotating body 3 of the MRR sensor.The bias magnet 6 is fixed to the dish sensor 4, and its magnetism is constant ( N pole) magnetic field is always MRR
Because it is designed to act on the sensor.
ＭＲＲセンサには、永久磁石回転体３の磁界と、バイア
ス用磁石６の磁界との合成磁界が作用し、永久磁石回転
体３の永久磁石による磁界は電動機の回転に伴ってその
大きさと磁性とが変化するので。A composite magnetic field of the magnetic field of the permanent magnet rotating body 3 and the magnetic field of the bias magnet 6 acts on the MRR sensor, and the magnetic field due to the permanent magnet of the permanent magnet rotating body 3 changes in size and magnetism as the motor rotates. Because it changes.
縄センサ４の検出端子Ａ、Ｅより、電動機の回転子軸２
の位置及び回転方向が検出できる。From the detection terminals A and E of the rope sensor 4, the rotor shaft 2 of the motor
The position and direction of rotation can be detected.
第５図（ｃ）は、検出端子Ａ、Ｅの接地電位に対する電
圧を２回転体が永久磁石の着磁ピッチλＰの間移動した
場合の変化を示すもので、バイアス用磁石６の磁界の大
きさを調整することで２回転体の移動角に対してほぼ正
弦波状の変化をし、また検出端子ＡとＢに現われる電圧
信号の位相角は（１／４）・Ａ１となっており、電気角
で９０度の位相角となり電動機制御に必要な特性を備え
ている。FIG. 5(c) shows the change in the voltage of the detection terminals A and E with respect to the ground potential when the two rotating bodies are moved by the magnetization pitch λP of the permanent magnets, and the magnitude of the magnetic field of the bias magnet 6 is shown in FIG. By adjusting the angle, the movement angle of the two rotating bodies changes almost sinusoidally, and the phase angle of the voltage signal appearing at the detection terminals A and B is (1/4)·A1, and the electric It has a phase angle of 90 degrees and has the characteristics necessary for motor control.
ＭＲＲセンサの出力を矩形波に整形するには、従来、第
６図（ａ）に示す回路が用いられていた。即ち。Conventionally, a circuit shown in FIG. 6(a) has been used to shape the output of the MRR sensor into a rectangular wave. That is.
抵抗Ｒ１と几、の直列接続回路及び抵抗Ｒｓと几、の直
列接続回路を設けて同じ電圧Ｖ。を印加し、抵抗Ｒ１と
Ｒ２の中間接続点とＭＲセンサ出出力端子色をＡ相用オ
ペアンプＵ１に入力し、抵抗Ｒ８とＲ４の中間接続点と
ＭＲセンサ出力端子ＢとをＢ相用オペアンプＵ！２に入
力して夫々を矩形波に整形するもので。The same voltage V is provided by providing a series connection circuit of resistors R1 and 几 and a series connection circuit of resistors Rs and 几. , input the intermediate connection point between resistors R1 and R2 and the MR sensor output terminal color to the A-phase operational amplifier U1, and input the intermediate connection point between the resistors R8 and R4 and the MR sensor output terminal B to the B-phase operational amplifier U. ! 2 and formats each into a square wave.
矩形波の波形を４個の抵抗Ｒ１〜Ｒ４の抵抗値によって
調整するようになっている。The waveform of the rectangular wave is adjusted by the resistance values of four resistors R1 to R4.
ところが２Ｍ几センサを構成している素子Ａ ｔ ”−
Ａ ４と抵抗Ｒ１〜Ｒ４とは温度特性が異なるために９
周囲温度の変化により波形が変化するという問題があり
、この問題を解決する一つの手段として、第６図（ｂ）
及び（Ｃ）に示すように、８個の磁気抵抗素子Ａ８〜Ａ
４．−Ｂｌ〜Ｂ４で構成されるＭＲＲセンサ使用した磁
気エンコーダが提案されている。第６図（ｂ）は８個の
磁気抵抗２（子を用いた場合の電気回路図。However, the element A t ”- which constitutes the 2M sensor
A4 and resistors R1 to R4 have different temperature characteristics, so 9
There is a problem that the waveform changes due to changes in the ambient temperature, and one way to solve this problem is as shown in Fig. 6 (b).
And as shown in (C), eight magnetoresistive elements A8 to A
4. - A magnetic encoder using MRR sensors composed of B1 to B4 has been proposed. FIG. 6(b) is an electrical circuit diagram when eight magnetoresistive elements 2 are used.
（ｃ）はその場合のＭＩＬセンサと永久磁石回転体との
配置関係図を示しており、また、（ｄ）は磁界強度の分
布図、（ｅ）は各出力信号の波形図な示している。この
ように、波形整形に抵抗な使用しないで、８個の磁気抵
抗素子を用℃・ろＭＲＲセンサすることで。(c) shows the arrangement relation diagram between the MIL sensor and the permanent magnet rotating body in that case, (d) shows the distribution diagram of the magnetic field strength, and (e) shows the waveform diagram of each output signal. . In this way, eight magnetoresistive elements can be used to shape the waveform without using any resistance.
周囲温度による変化を小さくすることができると共に、
８個の孝子全部が磁界強度の変化に対応して出力を変化
させることがら、センサとしての出力感度が４素子使用
時に比較して向上すると℃・５特長もある。Changes due to ambient temperature can be reduced, and
Since all eight elements change their output in response to changes in magnetic field strength, the output sensitivity as a sensor is improved compared to when four elements are used, which also has the advantage of ℃5.
しかしながら、上記した従来技術には次のような問題点
があった。即ち、電動機制御の精度を高くするには、永
久磁石回転体３に設ける永久磁石の数を増加する必要が
あるが、ＭＲセンサ４の素子の配設ピッチλＭＲを一定
とすると永久磁石の着磁ピッチλ２も定まるので、永久
磁石の数な増加するには永久磁石回転体３の直径を大き
くする必要があることになり、制御精度を高くするには
大径の回転体が必要となり磁気エンコーダが大形になる
と（・う問題があった。However, the above-mentioned conventional technology has the following problems. That is, in order to increase the accuracy of motor control, it is necessary to increase the number of permanent magnets provided in the permanent magnet rotating body 3, but if the arrangement pitch λMR of the elements of the MR sensor 4 is constant, the magnetization of the permanent magnets Since the pitch λ2 is also determined, it is necessary to increase the diameter of the permanent magnet rotating body 3 in order to increase the number of permanent magnets, and to increase control accuracy, a large diameter rotating body is required, and the magnetic encoder is There was a problem when it became large.
本発明の目的は、従来技術における８個の磁気抵抗素子
で構成する進センサを用し・る場合の上記した問題点を
解決し、磁気抵抗素子の配設ピッチλＭｌ’ｌと永久磁
石回転体の直径を一定とし、永久磁石の着磁ピッチオア
を変化するだけで、異なった分解度の磁気エンコーダを
形成し、永久磁石回転体の直径を大きくすることなく、
より高い分解度とすることのできる磁気エンコーダを提
供することにある。An object of the present invention is to solve the above-mentioned problems when using an advance sensor composed of eight magnetoresistive elements in the prior art, and to improve the arrangement pitch λMl'l of the magnetoresistive elements and the permanent magnet rotating body. By keeping the diameter constant and changing the magnetization pitch or of the permanent magnets, magnetic encoders with different resolutions can be formed, without increasing the diameter of the permanent magnet rotating body.
An object of the present invention is to provide a magnetic encoder that can provide higher resolution.
本発明の特徴は、永久磁石回転体に設ける永久磁石の着
磁ピッチオアと、 ＭＲセンサを形成する磁気抵抗素
子の配設ピッチλＭＲとの関係を、Ωを４の倍数を除く
３以上の自然数としてλＰ＝’ （８／ｎ ）・λＭＲ
とする構成を採用することにある。A feature of the present invention is that the relationship between the magnetization pitch OR of the permanent magnets provided in the permanent magnet rotating body and the arrangement pitch λMR of the magnetoresistive elements forming the MR sensor is determined by setting Ω to a natural number of 3 or more excluding multiples of 4. λP=' (8/n)・λMR
The goal is to adopt a configuration that
前述した関係式λＰ＝ （８／ｎ ）・λＭＲのｎを種
々の自然数として、永久磁石の着磁ピッチλ１を定める
場合にｎ＝１とｎ＝２はすでに従来技術で採用している
ものであり、従って、ｎ＝２及びｎ＝１は共に採用せず
、ｎを３以上の自然数とする場合について以下に述べる
。 ゛
ｎ＝３の場合のＭＲセンサ４と永久磁石回転子３との配
置関係を第１図（ａ）に、ＭＲセンサ４に作用する磁界
強度の変化を（ｂ） Ｋ 、 ＭＲセンサの電気信号出
力の変化を（ｃ）に、オペアンプＵ、、Ｕ１１の実効入
力を（ｄ）に、波形整形後の矩形波形図を（ｅ）に示す
。ＭＲセンサを構成する８個の磁気抵抗素子の配設ピッ
チλＭＲと、永久磁石の着磁ピッチλ２との間にはλ２
二（８／３ ）・λＭＢの関係式が成立しており、かつ
、第６図（Ｃ）に示すｎ＝２の従来構成と異なり。When determining the magnetization pitch λ1 of a permanent magnet by setting n in the above-mentioned relational expression λP=(8/n)・λMR to various natural numbers, n=1 and n=2 have already been adopted in the prior art. Therefore, a case will be described below in which both n=2 and n=1 are not adopted, and n is a natural number of 3 or more. Figure 1 (a) shows the arrangement relationship between the MR sensor 4 and the permanent magnet rotor 3 when n = 3, and (b) shows the change in the magnetic field strength acting on the MR sensor 4. (c) shows the change in output, (d) shows the effective inputs of the operational amplifiers U, U11, and (e) shows the rectangular waveform after waveform shaping. There is a distance λ2 between the arrangement pitch λMR of the eight magnetoresistive elements constituting the MR sensor and the magnetization pitch λ2 of the permanent magnets.
The relational expression 2(8/3)·λMB is established, and this is different from the conventional configuration where n=2 shown in FIG. 6(C).
バイアス用磁石を備えていない。Does not have a bias magnet.
第１図に示したｎ＝３の実施例は次のように動作する。The n=3 embodiment shown in FIG. 1 operates as follows.
第１図（ａ）の図示状態では素子Ａ、は磁束が零の位置
にあり、従って抵抗値は最大であり、一方、素子Ａ４は
最大磁束の位置にあり、従って抵抗値が最低であり、こ
のため出力端子ＡＯｔの電圧レベルは（ｃ）図のＡ。Ｉ
においてａ目の位置となる。また、このとき、素子Ａ２
は最大磁束を受ける位置にあり、一方、素子Ａ、は磁束
が零の位置にあるから。In the illustrated state of FIG. 1(a), element A is at a position where the magnetic flux is zero and therefore has the maximum resistance value, while element A4 is at the position where the magnetic flux is maximum and therefore the resistance value is the lowest. Therefore, the voltage level of the output terminal AOt is A in the diagram (c). I
This is the a-th position. Also, at this time, element A2
is at the position receiving the maximum magnetic flux, while element A is at the position where the magnetic flux is zero.
出力端子Ａ。２の電圧レベルは（Ｃ）図のＡｔ）２にお
いてａ２１の位置となる。ａ１□とａ２１の電圧がオペ
・アンプＵ１に入力され、オペ・アンプＵ１の実効入力
は（ｄ）図人相のＡＰＩの位置となる。Output terminal A. The voltage level of 2 is at the position a21 in At)2 of the figure (C). The voltages of a1□ and a21 are input to the operational amplifier U1, and the effective input of the operational amplifier U1 is at the position of the API in the figure (d).
他方、素子Ｂ、と素子Ｂ４とはほぼ等しい磁束を受ける
位置にあり、従って素子の抵抗値がほぼ等しくなるので
、出力端子Ｂ。１の電圧レベルは零となり、（ｄ区のＢ
。１の０の（ｉ置となり、また、素子Ｂ２と素子Ｂ、も
ほぼ等しい磁束を受ける位置にあり、従って出力端子Ｂ
Ｏ２の電圧レベル、も零となり。On the other hand, since elements B and B4 are in positions where they receive approximately the same magnetic flux, and therefore have approximately the same resistance value, the output terminal B. The voltage level of 1 becomes zero, and (B of d area
. 1 of 0 (i position), and element B2 and element B are also in positions where they receive almost equal magnetic flux, so output terminal B
The voltage level of O2 also becomes zero.
（Ｃ）図のＢＯ２の０の位置となる。出力端子Ｂ。ｌ
＋ ＢＯＱの電圧レベルが共に零で、従ってオペ・アン
プＵ２の実効入力は（ａ）図、Ｂ相のＯの位置となる。(C) This is the 0 position of BO2 in the figure. Output terminal B. l
+BOQ voltage levels are both zero, so the effective input of the operational amplifier U2 is at the position O of the B phase in Figure (a).
次に、永久磁石回転子３が第１図（ａ）に示す位置から
査λＰだけ矢印方向に移動すると、素子Ａ！の受ける磁
束と、素子Ａ４の受ける磁束がほぼ等しくなり、出力端
子ＡＯｔの電圧レベルが零となり、素子Ａ２と素子Ａ３
とが夫々受ける磁束もほぼ等しく。Next, when the permanent magnet rotor 3 moves in the direction of the arrow by a distance λP from the position shown in FIG. 1(a), element A! The magnetic flux received by element A4 becomes almost equal to the magnetic flux received by element A4, the voltage level of output terminal AOt becomes zero, and element A2 and element A3
The magnetic flux received by each is almost equal.
出力端子ＡＯ，の電圧レベルも零となり、オペアンプＵ
１の実効入力が零となるから人相出力が零となろ。一方
、素子Ｂ１が受ける磁束が最大となり、素 □子Ｂ
４が受ける磁束が零となるから出力端子Ｂ。１の電圧レ
ベルはｂｔｔの位置となり、素子Ｂ２が受ける磁束が零
となり、素子Ｂ、が受ける磁束が最大となるから出力端
子Ｂｏ２の電圧レベルはｂ２□の位置となり、オペアン
プＵ２の実効入力はＥＰｌの位置となる。The voltage level at the output terminal AO also becomes zero, and the operational amplifier U
Since the effective input of 1 becomes zero, the physiognomy output becomes zero. On the other hand, the magnetic flux received by element B1 becomes maximum, and element B
Output terminal B because the magnetic flux received by 4 becomes zero. The voltage level of 1 is at the btt position, the magnetic flux received by element B2 is zero, and the magnetic flux received by element B is maximum, so the voltage level of the output terminal Bo2 is at the b2□ position, and the effective input of the operational amplifier U2 is EPl. The position will be
以下、同様に永久磁石回転子が１λだけ回転すｐ
るごとに出力端子Ａｏ１＋ ＡＯ１１＋ １３０１
＋ Ｂｏ２の電圧レベルは（Ｃ）図に示すようにｌ
ＪＱ＋ Ｏｒ ａｌｌｌ ０Ｈａ１４ｒ ０１ ａｌ
ｌｌ ； ａＱ２ｐ Ｏｓ ａｌ１８＋ Ｏｒ ａ２４
＋ ０ ＋ａｌｌｌｌ ；Ｏ，ｂＩＱ＋ Ｏｒ ｋ）１
８） Ｏｒ ｂ１４＋ Ｏｉｏｌ ｂａｇ。Similarly, every time the permanent magnet rotor rotates by 1λ, the output terminal Ao1+ AO11+ 1301
+ The voltage level of Bo2 is l as shown in figure (C)
JQ+ Or all 0Ha14r 01 al
ll ; aQ2p Os al18+ Or a24
+ 0 +allll ;O, bIQ+ Or k)1
8) Or b14+ Oil bag.
０＋ ｂａｓ、Ｏｓ ｂｑ４ｔ Ｏと変化し、オペア
ンプＵｌ。Changes to 0+ bas, Os bq4t O, operational amplifier Ul.
ＵＱの実効入力は（ｄ）図のＡＰａｒ Ｏｒ ＡＰａ
＋ ０１ ＡＰ４１０、 ＡＰ５−−− ＋ ＯＨＢＦ
２＋ ０＋ ＢＰａ＋ ０９ＢＰ４＋ ｏｌ−ｍ−と変
化し、波形整形後の出力は（ｅ）図に示すＡ相、Ｂ相の
矩形波となり２人相とＢ相とは振幅と・１
ピッチが夫々相等しく２位相か、λＰ（出力波の周期で
は１周期分）だけずれており、これは電気角で頭皮の位
相差に相当する。The effective input of UQ is (d) APar Or APa in the figure
+ 01 AP410, AP5--- + OHBF
2+ 0+ BPa+ 09BP4+ ol-m-, and the output after waveform shaping becomes the rectangular wave of A phase and B phase shown in the figure (e). The two-person phase and B phase have the same amplitude and pitch. There is a difference of 2 phases or λP (one period in terms of the period of the output wave), which corresponds to the phase difference of the scalp in electrical angle.
上記のｎ＝３の実施例においては、永久磁石回転子３が
ピッチリだけ回転する時にＭＲセンサ４のＡ相、Ｂ相の
各相には夫々２周期分の波形が発生し、第６図に示した
従来のｎ＝２の構成に比し２倍の周期の出力となり、一
方、永久磁石の着磁ビ、２
ノチか１となっているので、永久磁石回転子が一回転す
る間に発生する出力波の数は従来例のｎ＝２の場合に比
し３倍となり、ｎ−２の従来例と比較し、同一直径の永
久磁石回転子を使用して分解度を３倍とすることができ
る。In the above embodiment where n=3, when the permanent magnet rotor 3 rotates exactly, two cycles of waveforms are generated in each of the A and B phases of the MR sensor 4, as shown in FIG. The output is twice as long as the conventional n=2 configuration shown above, and on the other hand, since the permanent magnet is magnetized with only 2 notches or 1, the output occurs during one rotation of the permanent magnet rotor. The number of output waves to be generated is three times that of the conventional example when n = 2, and compared to the conventional example of n-2, the resolution is tripled by using a permanent magnet rotor with the same diameter. I can do it.
第２図は本発明のｎ＝５の場合の実施例図で（ａ）は縄
センサ４と永久磁石回転子３との配置関係図。FIG. 2 is an embodiment diagram of the present invention in the case of n=5, and (a) is a diagram showing the arrangement relationship between the rope sensor 4 and the permanent magnet rotor 3.
（ｂ）はＭＲセンサ４に作用する磁界強度の変化図、オ
ペアンプＵ１．Ｕ２の実効入力を（ｃ）に、波形整形後
の出力を（ｄ）に示す。ｎ＝５の場合もｎ＝３の場合と
同じくバイアス用磁石を備える必要はなく、永久磁石の
１ピツチλ１内でＭＲセンサの出力には２周期分の波形
が発生し、永久磁石の着磁ピッチが百となり、永久磁石
回転子が一回転する間に発生する出力波の数は従来例の
ｎ＝２の場合に比し５倍となり２分解度を５倍とするこ
とができる。(b) is a diagram of changes in magnetic field strength acting on the MR sensor 4, and operational amplifier U1. The effective input of U2 is shown in (c), and the output after waveform shaping is shown in (d). In the case of n=5, as in the case of n=3, there is no need to provide a bias magnet, and two cycles of waveforms are generated in the output of the MR sensor within one pitch λ1 of the permanent magnet, and the magnetization of the permanent magnet is The pitch is 100, and the number of output waves generated during one rotation of the permanent magnet rotor is 5 times that of the conventional case where n=2, and the 2 resolution can be increased 5 times.
これに対し、ｎ−４の場合は、永久磁石がどの位置にあ
っても、 ＭＲセンサ内の直列接続された各孝子Ａ、と
Ａ４．ＡｌｌとＡ１１ ＋ Ｂ１とＢ４Ｔ Ｂ２とＢ１
１は夫々、常に同じ強さの磁界位置にあって各出力端子
ＡＯ１、ＡＯ２＋ Ｂｏｌ ＋ ＢＯＱに出力電圧
が発生せず。On the other hand, in the case of n-4, no matter where the permanent magnet is located, each of the serially connected Takako A and A4. All and A11 + B1 and B4T B2 and B1
1 are always at the same magnetic field position with the same strength, and no output voltage is generated at each output terminal AO1, AO2+Bol+BOQ.
磁気エンコーダとして動作しないから、ｎ＝４の配置は
採用することができない。この関係は単にｎ＝４の場合
のみでなく、４の倍数全部について同様であるからｎが
４の倍数の場合は本発明から除外される。The arrangement with n=4 cannot be adopted because it does not operate as a magnetic encoder. This relationship holds true not only for n=4 but also for all multiples of 4, so cases where n is a multiple of 4 are excluded from the present invention.
以上に説明したようにλＰ” （８／ｎ ）・λＭＨの
条件において、８個の磁気抵抗素子より成る尼センサを
使用し、同一直径の永久磁石回転子を備えた磁気エンコ
ーダにおいて、ｎの値を種々に選定した場合の分解度を
第３図にまとめて示しである。As explained above, under the conditions of λP'' (8/n)・λMH, in a magnetic encoder equipped with a permanent magnet rotor of the same diameter and using a magnetic sensor consisting of eight magnetoresistive elements, the value of n Figure 3 summarizes the degree of resolution when various selections are made.
以上説明したように９本発明によれば、８個の磁気抵抗
素子を用いるＭＲセンサとすることで９周囲温度の影響
をなくし出力感度を向上させるとともに、永久磁石回転
子の直径を大きくすることなく磁気エンコーダとしての
分解度を数倍に増大させることができる。As explained above, according to the present invention, an MR sensor using eight magnetoresistive elements eliminates the influence of ambient temperature, improves output sensitivity, and increases the diameter of the permanent magnet rotor. The resolution of the magnetic encoder can be increased several times without any problems.
第１図はｎ ＝３の場合の本発明実施例で（ａ）は凧セ
ンサと永久磁石回転子との配置関係図、（ｂ）は磁界強
度の変化図、（Ｃ）はＭＲセンサ出カ波形図、（ｄ）は
オペアンプ実効入力の波形図、（ｅ）は波形整形後の矩
形波形図、第２図はｎ＝５の場合の本発明実施例で（ａ
）は皿センサと永久磁石回転子の５配置関係図。
（ｂ）は磁界強度の変化図、（Ｃ）はオペアンプ実効入
力波形図、（ｄ）は波形整形後の出力波形図、第３図は
本発明における。ｎの変化による分解度の変化を示す図
、第４図は磁気抵抗素子の一般特性説明図第５図は従来
例の説明図で（ａ）は側面図とそのＸ−Ｘ断面図、（ｂ
）はＭＲセンサと永久磁石回転体との配置関係図、（Ｃ
）は出力信号波形図、（ｄ）はＭＲセンサの電気回路図
、第６図は従来技術の説明図で（ａ）は矩形波に整形す
る回路図、（ｂ）は磁気抵抗素子を８個用いる従来回路
図、（Ｃ）はその場合のＭＲセンサと永久磁石回転子と
の配置関係図、（ｄ）は磁界強度の変化図、（ｅ）はＭ
几センサ出力信号波形図である。
〈符号の説明〉Figure 1 shows an embodiment of the present invention in which n = 3. (a) is a diagram of the arrangement relationship between the kite sensor and the permanent magnet rotor, (b) is a diagram of changes in magnetic field strength, and (C) is a diagram of the MR sensor output. Waveform diagram, (d) is a waveform diagram of the effective input of the operational amplifier, (e) is a rectangular waveform diagram after waveform shaping, and FIG.
) is a diagram showing the relationship between the plate sensor and the permanent magnet rotor. (b) is a change diagram of magnetic field strength, (C) is an operational amplifier effective input waveform diagram, (d) is an output waveform diagram after waveform shaping, and FIG. 3 is according to the present invention. FIG. 4 is a diagram showing the general characteristics of a magnetoresistive element. FIG. 5 is an explanatory diagram of a conventional example. (a) is a side view and its XX cross-sectional view, (b)
) is a diagram of the arrangement relationship between the MR sensor and the permanent magnet rotating body, (C
) is an output signal waveform diagram, (d) is an electric circuit diagram of the MR sensor, and Figure 6 is an explanatory diagram of the conventional technology. The conventional circuit diagram used, (C) is a diagram of the arrangement relationship between the MR sensor and the permanent magnet rotor in that case, (d) is a diagram of changes in magnetic field strength, and (e) is a diagram of the relationship between the MR sensor and the permanent magnet rotor.
FIG. 3 is a waveform diagram of a sensor output signal. <Explanation of symbols>
Claims (1)
８個Ａ＿１、Ｂ＿１、Ａ＿２、Ｂ＿２、Ａ＿３、Ｂ＿３
、Ａ＿４、Ｂ＿４をこの順に等ピッチλ＿Ｍ＿Ｒで配列
し、Ａ＿１とＡ＿４を、Ａ＿２とＡ＿３を、Ｂ＿１とＢ
＿４を、Ｂ＿２とＢ＿３を夫々直列に接続してなる４回
路を並列接続した回路に一定電圧を印加し、上記４直列
接続回路の各中間接続点Ａ＿０＿１、Ａ＿０＿２、Ｂ＿
０＿１、Ｂ＿０＿２を電圧検出端子とする磁気抵抗セン
サを、λ＿ＰのピッチでＮ極、Ｓ極が交互に着磁された
永久磁石に対して空隙を介して対向配置することで上記
永久磁石の移動量に応じた電圧信号を上記電圧検出端子
より得る磁気エンコーダにおいて、上記永久磁石の着磁
ピッチλ＿Ｐと上記磁気抵抗素子の配設ピッチλ＿Ｍ＿
Ｒとの関係を、ｎを４の倍数を除く３以上の自然数とし
てλ＿Ｐ＝（８／λ）・λ＿Ｍ＿Ｒとしたことを特徴と
する磁気エンコーダ。Eight magnetoresistive elements A_1, B_1, A_2, B_2, A_3, B_3 whose electrical resistance changes depending on the magnetic field strength
, A_4, B_4 are arranged in this order with equal pitch λ_M_R, A_1 and A_4, A_2 and A_3, B_1 and B
A constant voltage is applied to a circuit in which four circuits each formed by connecting B_2 and B_3 in series are connected in parallel, and each intermediate connection point A_0_1, A_0_2, B_ of the four series connected circuits is connected.
By arranging a magnetoresistive sensor having voltage detection terminals 0_1 and B_0_2 opposite to a permanent magnet whose N pole and S pole are alternately magnetized at a pitch of λ_P through an air gap, the amount of movement of the permanent magnet can be adjusted. In the magnetic encoder which obtains a voltage signal from the voltage detection terminal according to the voltage, the magnetization pitch λ_P of the permanent magnet and the arrangement pitch λ_M_
A magnetic encoder characterized in that the relationship with R is λ_P=(8/λ)·λ_M_R, where n is a natural number of 3 or more excluding multiples of 4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60002099A JPS61161418A (en) | 1985-01-11 | 1985-01-11 | Magnetic encoder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60002099A JPS61161418A (en) | 1985-01-11 | 1985-01-11 | Magnetic encoder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS61161418A true JPS61161418A (en) | 1986-07-22 |
Family
ID=11519899
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60002099A Pending JPS61161418A (en) | 1985-01-11 | 1985-01-11 | Magnetic encoder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61161418A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4910788A (en) * | 1988-03-26 | 1990-03-20 | Rikuro Shimizu | Slide bearing unit |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5441335A (en) * | 1977-09-03 | 1979-04-02 | Pola Kasei Kogyo Kk | Cosmetics |
| JPS5559314A (en) * | 1978-10-27 | 1980-05-02 | Sony Corp | Magnetic scale signal detector |
| JPS5690213A (en) * | 1979-12-24 | 1981-07-22 | Nec Corp | Position detector |
-
1985
- 1985-01-11 JP JP60002099A patent/JPS61161418A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5441335A (en) * | 1977-09-03 | 1979-04-02 | Pola Kasei Kogyo Kk | Cosmetics |
| JPS5559314A (en) * | 1978-10-27 | 1980-05-02 | Sony Corp | Magnetic scale signal detector |
| JPS5690213A (en) * | 1979-12-24 | 1981-07-22 | Nec Corp | Position detector |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4910788A (en) * | 1988-03-26 | 1990-03-20 | Rikuro Shimizu | Slide bearing unit |
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