JPH0254883B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in magnetic scale signal detection devices formed from ferromagnetic metal magnetoresistive thin films.

Some conventional magnetic scale signal detection devices are made of a segmented magnetoelectric transducer made of a ferromagnetic metal magnetoresistive thin film, as is known, for example, from Japanese Patent Application Laid-Open No. 50-81117 and US Pat. No. 3,949,345. This is based on arranging each component of the element so as to correspond to each magnetic graduation (magnetic grating) of a magnetic scale, but from the standpoint of practical use, there are the following problems.

(a) Since the size of the magnetic scale is limited by the dimensions of the magnetoelectric conversion element, it is not possible to create a magnetic scale with a short wavelength, and the wavelength is limited to λ > 1 mm. In order to make the resolution (reading unit) of the magnetic scale finer, the degree of interpolation must be increased, which necessitates the adoption of a phase modulation detection method, making it difficult to realize an inexpensive detection circuit.

(b) The structural dimension L of the magnetoelectric conversion element is, for example, λ=2
mm, and the number of components N=10, L≧40 mm, which makes it large and expensive.

Furthermore, in contrast to such a multi-element structure, there is also a known single-element structure 1 as shown in FIG. Therefore, it is necessary to increase the degree of interpolation, and if a phase modulation detection method is adopted, it is inevitable that the detection circuit will become expensive.

Furthermore, Japanese Patent Application No. 52-114699, which is the earlier application of the present invention, proposed that each element of the magnetic head 3 be arranged in correspondence with the pitch λ of each magnetic grating 4 of the scale, as shown in FIG. ing.

The magnetic grating 4 is recorded at a predetermined pitch λ on a magnetic thin film 4 ₂ formed on a substrate 4 ₁ made of a non-magnetic material. The magnetic head 3 is a magnetoresistive element made of a ferromagnetic metal thin film, and is movably held on the magnetic grid 4 with a certain clearance Δ. The reason why conventional magnetic heads consisting of magnetoresistive elements made of thin ferromagnetic metal films could not detect magnetic scale signal magnetic fields of short wavelengths (short magnetic lattice pitches) is because the constituent elements of the above elements correspond to the phase of the magnetic lattice as units. The point is that it is made to directly respond to changes in the direction of the in-plane magnetic field.

Therefore, in the example shown in FIG. 2, in order to increase the detection sensitivity of the magnetic scale signal, reduce the pitch of the magnetic grating 4, and reduce the interpolation of the detection signal,
As shown in the figure, the magnetoresistive paths ₃₁ forming each component of the magnetoresistive element 3 are arranged in a zigzag pattern corresponding to each phase of the magnetic grating 4. However, as the pitch of the magnetic grating 4 becomes smaller, the spread of the leakage magnetic field from the magnetic grating is also drastically reduced, making it impossible to saturate the components of the magnetoresistive element 3, and if left as is, the occurrence of magnetic hysteresis becomes a problem. Therefore, as shown in the figure, a magnetic path member 3 ₂ made of a highly permeable thin film is provided for each magnetoresistive path 3 ₁ to form a closed magnetic path with each magnetic lattice. With this configuration, the magnetic path member 3 ₂ induces leakage magnetic flux from the magnetic grating 4, so that the magnetoresistive element 3 can be placed in a sufficient saturation magnetic field.

In contrast, in Japanese Patent Application No. 52-119468, which is the earlier application of the present invention, which has further improved practicality, each element of the magnetic head 5 is made to correspond to the pitch λ of the magnetic grating 6, as shown in FIG. It is proposed to arrange the

As shown in the figure, the magnetic head 5 has magnetoresistive paths 5 ₁ and 5 ₂ formed by magnetoresistive elements arranged diagonally and diagonally at an appropriate angle θ' in correspondence with the phase of the magnetic grating. It is set up. Each component of the magnetoresistive path is provided so as to have a phase difference of λ/2 with respect to the wavelength λ of the magnetic grating,
One end of each magnetic resistance path is connected to current terminals a and c, and the other end is connected to a midpoint output terminal b, forming a three-terminal split type configuration.

A bias magnetic field H _B is applied to the magnetic head 5 in a direction substantially perpendicular to the signal magnetic field H _S .

Therefore, the plane magnetic field H〓 of the magnetic head 5 is the signal magnetic field H〓 _S
The resultant magnetic field is determined by the bias magnetic field H〓 _B , and H〓 _S
and H〓 The strength H and direction θ are determined by the magnitude of _B. Therefore, the oblique angle θ of the magnetoresistive path is θ′≒
It is desirable to design the angle to be 90°-θ.

In general ferromagnetic metals, the resistance is at its maximum when the direction of the current flowing through it and the direction of the magnetic field acting on it are parallel, and the resistance is at its minimum when they are perpendicular to each other. Therefore, in the illustrated arrangement, the magnetic resistance path has a maximum resistance value between terminals a and b, and a minimum resistance value between terminals c and b. Furthermore, if the position of the magnetic head is displaced by λ/2 with respect to the illustrated magnetic grid, the resistance between the terminals will have a relationship opposite to that described above.

Thus, when a driving voltage is applied between terminals a and c, the magnetic head 5 undergoes a relative displacement X with respect to the magnetic grating 6.
Generates output according to.

In the above case, each piece of the magnetic head is configured to be inclined at a predetermined angle with respect to the magnetic grid. However, according to this configuration, since each element is distributed over the phase of λ/2 of the magnetic grating, the magnetoresistive effect is considered to be canceled out considerably, and there is a problem in terms of the efficiency of outputting the detection signal.

The present invention has been made in order to improve the above-mentioned problems of the prior art, and to contribute to the realization of an inexpensive digital scale by making it possible to form a magnetic scale with a short wavelength and by making it possible to apply a simple detection circuit. An object of the present invention is to provide a magnetic scale signal detection device.

In order to detect magnetic scale signals having relatively short wavelengths, the apparatus of the present invention uses a magnetic scale signal detection element having the following configuration.

(a) Each element of the detection element made of a ferromagnetic material having an anisotropic effect of magnetoresistance is arranged in parallel in accordance with the characteristic wavelength of the magnetic grating.

(b) Provide a current path that connects the above-mentioned pieces. Generally, this current path is formed of the same magnetic thin film as the elemental piece, but in order to reduce the influence of the magnetoresistive effect, it is effective to lower the magnetic resistance value by designing a wide range that corresponds to the elemental piece. It is.

(c) Two components consisting of the above elemental piece group are spaced at a predetermined distance {nλ/2, (n/2+1/2)λ, or (n/2+1/4)λ depending on the necessity of the element configuration. Select one. n is an integer} and are arranged with a distance between them, connected in series through a current path, and an output terminal is formed at the connection point.

(d) In order to obtain a two-phase output for the purpose of direction discrimination and interpolation, the two detection elements are arranged at a predetermined interval (for example, (m/2+1/8)λ, (m/2+1/4)λ, etc.). However, m is an integer}.

(E) A bias magnetic field H _B is applied in the direction of the elemental piece or in a direction forming a predetermined angle (mainly 45° in practice) with the elemental piece. This bias magnetic field is set to such a strength that the hysteresis voltage of the detection element can be ignored, for example, 150 O _e or more.

This avoids the influence of magnetization hysteresis of the elemental pieces, and reduces variations in output amplitude.

(F) The detection element is arranged to face the magnetic lattice plane in view of the need to operate in a place where the signal magnetic field is strong.

(g) When the detection element is formed of a ferromagnetic thin film having an anisotropic effect of magnetoresistance on the substrate,
A protective film (or protective plate) of a predetermined thickness is coated to face the magnetic lattice surface. Generally, the clearance between the magnetic scale and the detection element is about 50μ or less, so such a configuration is effective.

(H) This configuration in which the magnetoresistive thin film element and the magnetic lattice face each other is extremely effective for increasing the density of the magnetic lattice. In order to reduce the interplanar spacing, it is preferable that the lead wire attachment portion of the magnetoresistive thin film element be disposed outside the magnetic grid.

Regarding the above items (c) and (e), to explain in more detail, for example, as shown in FIG. 20, two parallel pieces A ₁ and A ₂ are arranged λ/4 apart, and A parallel bias magnetic field H _B is applied to reduce each magnetic resistance to R ₁ ,
If R ₂ , then R ₁ = ρ⊥sin ² θ(x) + ρcos ² θ(x) (1) R ₂ = ρ⊥sin ² θ(x+λ/4) +ρcos ² θ(x+λ/4) (2) When a constant voltage V ₀ is applied to both terminals a and c of elemental pieces A ₁ and A ₂ , the voltage fluctuation V at the common terminal b
(x), then V(x) = V ₀ (R ₁ - R ₂ )/(R ₂ + R ₁ ), and this is the output from the head, so as R ₁ and R ₂ above, (1) and (2)
By substituting the formula, the following formula can be obtained.

V(x)=-△ρr ² V ₀ /2 (ρ+ρ ₀ r ² )cos4π/λ
x × {1+ρ⊥r ⁴ /4 (ρ+ρ ₀ r ² ) sin ² 4π/λx}
^-1 (3) However, 2ρ ₀ = ρ + ρ⊥, △ρ = ρ−ρ⊥, r =
In s/B, ρ and ρ⊥ are the intrinsic magnetic resistance of the elemental piece, B is the absolute value of the bias magnetic field H _B , and s is a constant related to the magnetic scale.

Next, as shown in Fig. 20, when the spacing between the pieces A ₁ and A ₂ is λ/2 and a bias magnetic field H _B is applied to the pieces in a 45° direction, the magnetic resistance R of A ₁ and A _{2 1} , R ₂ is R ₁ = ρ⊥sin ² θ(x) + ρcos ² θ(x) (4) R ₂ = ρ⊥sin ² θ(x+λ/2) + ρcos ² θ(x+λ/2) (5) , the voltage fluctuation V(x) becomes as follows by substituting the above equations (4) and ( ₅ ) as R ₁ and R 2 of V(x) = V ₀ R ₁ − R ₂ / R ₁ + R ₂ .

V(x)=△ρV ₀ /2ρ ₀ sin2π/λx×(1
+△ρr ² ／4ρ ₀ sin ² 2π／λx＋ρ⊥r ² ／4ρ ₀ sin ⁴ 2π／
λx) ^-1 (6) As is clear from the above equations (3) and (6), the above (c) and
Output V obtained from elemental pieces A ₁ and A ₂ by method (e)
(x) are periodic functions of wavelength λ/2 and λ, respectively,
In particular, equation (3) shows that an output equivalent to a half wavelength can be obtained while using the same wavelength scale, and is found to be extremely effective in practice.

Embodiments of the apparatus of the present invention shown in the drawings according to the above-described configuration will be described below.

FIG. 4 shows an embodiment of the device of the present invention comprising detection elements 8, 8' in which the spacing between the pieces 7, 7' is λ/2.
These detection elements 8, 8' are placed face to face with the magnetic lattice surface 9 of the magnetic scale, and a bias magnetic field H _B is applied in the direction of the element. Note that a, a', c, c' are current terminals, b, b' are output terminals, and 10, 10' are current paths.

Further, the two components in which the above-mentioned pieces are directly connected by current paths 10 and 10' are arranged at an interval of (n/2+1/4)λ as shown in the figure.

In such an element configuration, the wavelength λ of the magnetic scale
Therefore, in order to obtain a two-phase output with a phase difference of 90°, two detection elements 8 and 8' may be arranged at an interval of (m/2+1/8)λ as shown in the figure.

As is clear from equation (3) above, this device is related to the bias magnetic field H _B divided by the square of the absolute value B, so the signal magnetic field of the magnetic scale is sufficiently large compared to the bias magnetic field H _B. This is effective when the value is large.

In the embodiment shown in FIG. 5, the elemental pieces are arranged with the interval λ,
A bias magnetic field is applied in a direction approximately 45° to the elements 7 and 7'.
It gives H _B. The two components 11 and 11' and 12 and 12' of the detection elements 8 and 8' are at an angle of 90° (=
These elements 11 and 12 and 11' and 12' should be connected to output terminals b and b' in an arrangement that has a phase difference of 180° (=λ/2). As is clear from equation (6), a detection signal output with a period of λ can be obtained. In addition, if a bias magnetic field H _B is applied to the elemental piece in the 45° direction as in this example,
In the absence of a magnetic signal from the magnetic scale, the signal output is in a zero potential state, for example as shown in FIG. 15a. That is, this zero potential is determined by the bias magnetic field and is not affected by the magnetic signal from the magnetic scale. Therefore, the stability of the zero potential is good, and highly accurate detection is possible.

With such an element configuration, the same frequency output as the wavelength frequency of the magnetic scale can be obtained, so in order to obtain a two-phase output with a phase difference of 90°, the two detection elements 8 and 8' should be spaced at a distance of (m/2+1/4)λ. (In the illustrated case, m=0).

In this device, if the resistance of each element of the detection element is formed to be approximately equal especially at the position where the signal magnetic field of the magnetic scale is zero, the zero crossing detection position described later can be stably determined.

The embodiment shown in FIG. 6 is a modification of the one shown in FIG.
The bias magnetic fields applied in the 45° direction are set in opposite directions (H _B −H _B ), so that it is equivalent to providing a phase difference of λ/2 with respect to the phase of the magnetic scale.

In the embodiment shown in FIG. 7, the magnetic scale has a two-track configuration 13, 13', and in order to obtain a two-phase output, a predetermined phase difference between these tracks {(m/2+1/4)λ or the angle formed with the bias magnetic field H _B is applied. When θ=45°, (m/2+1/2) λ} is provided, and the two detection elements 8 and 8' are arranged in the same phase.

Note that the operation of this embodiment is similar to that shown in FIG.

The embodiment shown in FIG. 8 has unique ideas in the following two points regarding the element configuration.

One of the features is that the magnetic scale is formed by tilting the magnetic grating 14, and the track width of the magnetic grating 14 can be made larger than the width of the magnetic scale. Therefore, the detection elements 8, 8'
Each elemental piece constituting the is also arranged at an angle.

The other one has elements 7 and 7' to obtain two-phase output.
The elements are arranged alternately at intervals of (m/2+1/4)λ, and the elements of element 7 and the elements of element 7' are arranged at intervals that are an integral multiple of the magnetic lattice pitch. It is characterized by configuring. Of course, the detection element may be configured according to either of the two feature points described above.

The embodiment shown in FIG. 8 exhibits the same detection function as the embodiment shown in FIG. 4 if θ=0, and the same detection function as the embodiment shown in FIG. 5 if θ=45°.

Furthermore, in the embodiments shown in FIGS. 6 to 8, the lead wire attachment parts a to c' of the magnetoresistive thin film element are arranged on both sides of the magnetic grating, and the above-mentioned configuration (H) is embodied. .

In the embodiment shown in FIG. 9, the pieces 7 and 7' forming the detection elements 8 and 8' are arranged in a zigzag pattern. However, for a detection element whose purpose is to read short-wavelength magnetic scale signals, a zigzag number of 2 to 4 as shown in the figure is usually appropriate.

In each of the embodiments described above, the element configuration is exemplified for the case where two-phase output is obtained for the purpose of determining the direction of relative motion between the detection device and the magnetic scale and interpolating the detection signal. It goes without saying that the detection element configuration of the apparatus of the present invention can also be applied to the case where a multiphase output is to be obtained in order to increase the degree of interpolation.

For example, it is known that when three-phase outputs are obtained with a phase difference of 60 degrees, 1/12 interpolation can be easily performed, as disclosed in Japanese Patent Publication No. 48-2258. To obtain such an output, three detection elements 8, 8' and 8'' may be arranged with a phase difference of (m/2+1/6)λ as shown in FIG. 10. However, in the embodiment shown in the figure, m=0.

Next, in each of the embodiments shown in FIGS. 4 to 10, a magnetic scale composed of a magnetic grating for transverse magnetic field (longitudinal direction) recording is used.

However, as shown in FIG. 11, even if a magnetic scale consisting of a magnetic grating 15 for longitudinal magnetic field recording is used, the planar magnetic field includes a signal magnetic field component H _S that is effective for driving the detection element. The detection element of the present invention can be applied. In the embodiment shown in Fig. 11, 1/
A four-element configuration of 8 to 8'' suitable for the 16 interpolation method is adopted.

Furthermore, the element configuration of the present invention can also be applied to a rotating magnetic scale. For example, as schematically shown in FIG. 12, the detection elements 8, 8' according to the configuration of the present invention described above are arranged in accordance with the phase of the magnetic grating 17 arranged equiangularly with respect to the rotation center of the rotary magnetic scale 16. By providing a bias magnetic field H _B at a predetermined angle θ, it is possible to detect a magnetic scale signal according to the rotation angle.

Further, in the embodiments shown in FIGS. 11 and 12 as well, the lead wire attachment portions a to c' of the magnetoresistive thin film element are arranged outside the magnetic grid.

Now, in order to obtain a predetermined pulse train signal by processing the detection signal obtained by the apparatus of the present invention using the zero-cross detection method, it is possible to employ interpolation discrimination methods classified into the following three types.

(a) A method of adding and subtracting the detection signal outputs to each other to obtain a polyphase signal to improve interpolation.

(b) A method of increasing interpolation by configuring the detection element to be multiphase and directly obtaining multiphase signals.

(c) A method to improve interpolation by obtaining polyphase signals by combining methods (a) and (b).

(1) First, the 1/8 interpolation method will be explained. In this case, if the detection signal is a sine wave, a triangular wave, or a detection signal with a similar waveform, the following interpolation discrimination method can be applied.

(a) Considering the case where the detection signal from the detection element has the same wavelength frequency as that of the magnetic grating (see the embodiment in Fig. 5), two detection signal outputs A and 90 degrees apart, as shown in Fig. 13a, are generated. B is obtained. Note that the waveforms of outputs A and B are shown as triangular waves to simplify the explanation.

This signal output is given to an adder 18 and a subtracter 19 as shown in FIG. 14 for addition and subtraction, and as shown in FIG. Addition/subtraction signals A+B and AB are created.

These four signal outputs appear with a phase difference of 45 degrees, and when they are passed through the Schmitt circuit 20, they become rectangular wave signals shown in FIGS. 13c to 13f. Further, when this rectangular wave signal is passed through a differentiating circuit 21, a pulse train that is reversed in positive or negative depending on the detection direction as shown by g to j in the figure is obtained.

At the two output terminals 22 of each Schmitt circuit, outputs with mutually opposite phases are generated. When these output signals are used as the gate opening/closing signals of the AND gate circuits 23 and 24 at the next stage of the differentiating circuit, when moving in the +x direction from the differentiating output, the pulse train signal shown in FIG.
Further, when moving in the -x direction, the pulse train signal shown in FIG. 1 can be obtained as the output of each AND gate circuit.

Therefore, the above pulse train signal is transferred to the reversible counter 2.
The amount of movement can be detected by counting by 5.

In contrast to method (a) above, method (b) yields the following results.

(b) Using the four detection elements described above with a phase difference of 45°, the following signal output can be obtained.

V _A = Esin (nλ + θ) V _B = Esin (nλ + θ - π/4) V _C = Esin (nλ + θ - π/2) V _D = Esin (nλ + θ - 3π/4) Briefly explain these four signal outputs. Therefore, when represented by triangular waves, they are represented by A to D in FIG. 15a, and when these are passed through a Schmitt circuit, they become rectangular wave signals shown by b to e in the same figure. This is the first
This corresponds to the rectangular wave signals c to f in Fig. 3,
For subsequent processing, the method shown in FIGS. 13 and 14 can be applied as is.

The output signal thus obtained is a digital signal that discriminates the moving direction of the detection element with respect to the magnetic scale and that divides one wavelength of the magnetic grating into eight.

(2) Next, the 1/16 interpolation method will be explained.

(a) As shown in FIG. 16a, a detection element is prepared to obtain four signal outputs with a phase difference of 45°. Then, these signal outputs are added and subtracted to produce four addition/subtraction signals shown in FIG. In this way, 8-phase signals with a phase difference of 22.5° are obtained, and one wavelength of the magnetic grating is divided into 16 by performing signal processing similar to the signal processing described above, as shown in Fig. 16 c to r. , T are obtained.

(b) Eight detection elements are arranged with a predetermined phase difference to directly obtain eight-phase detection signals with a phase difference of 22.5° as shown in FIG. 17a. Although this interpolation method increases the number of detection elements, since the interpolation signal is read from the zero-crossing point, high-precision interpolation can be achieved by accurately forming the pitch of the magnetic grid. Since no circuit is required, the circuit configuration is also simplified.

The signal output in FIG. 17a becomes the rectangular wave signals shown in FIG. By performing signal processing as shown in g, a 1/16 interpolated signal (r in the figure) is obtained.

(c) Two sets of 1/8 interpolation means can be used to construct 1/16 interpolation. For example, by obtaining another set of signal outputs in which the signal outputs shown in Figure 13a and b are shifted by a phase difference of 22.5°, the overall
This is a method to create an interpolated signal divided into 16 parts.

(A) Signal V _A = E ₁ sin (nλ + θ) (B) Signal V _B = E ₁ sin (nλ + θ - π/2) (A) + (B) Signal V _{A + B} = E ₂ sin (nλ + θ - π /4) (A) - (B) Signal V _AB = E ₂ sin (nλ + θ + π/4) (C) Signal V _C = E ₁ sin (nλ + θ - π/8) (D) Signal V _D = E ₁ sin ( nλ+θ−5π/8) (C)+(D) signal V _C+D =E ₂ sin(nλ+θ−3π/8) (C)−(D) signal V _CD =E ₂ sin(nλ+θ+π/8) The interpolation method is the interpolation method in section (a) above (Section 16).
The phase difference in the signal output from the detection element compared to Fig.
Therefore, although the arrangement intervals of the detection elements are different, they can be regarded as equivalent when viewed as eight-phase signal outputs.

Note that FIGS. 18a and 18b illustrate the circuit configuration of an actual detection element. As shown in the figure, a drive power supply terminal, a ground terminal, etc. can be made common to each element. Therefore, the number of terminals of the detection elements 8, 8' is set to 19th.
It is possible to reduce on thin film formation as schematically illustrated in the figure.

As is clear from the above description, according to the present invention, a short wavelength magnetic scale can be realized, and a simple detection circuit can be applied, and an inexpensive digital scale can be provided.

In particular, in the present invention, the detection element is arranged in a plane facing the magnetic grating, and a bias magnetic field is applied, which improves resolution, reduces output distortion, and suppresses unevenness in output amplitude. However, since the lead wire attachment portion is located outside the magnetic lattice plane, wiring work is facilitated even in a structure in which a bias magnetic field is applied in such a plane facing the plane.

[Brief explanation of drawings]

FIGS. 1 to 3 are diagrams showing the relationship between a conventional detection element and a magnetic scale, FIGS. 4 to 12 are schematic diagrams showing the configuration of each embodiment of the present invention, and FIGS. l is a waveform diagram to explain one method of 1/8 interpolation, Fig. 14 is a block diagram showing a 1/8 interpolation circuit, and Fig. 15 a to e are other methods of 1/8 interpolation. Waveform diagrams for explaining the method; FIGS. 16A to 16T are waveform diagrams for explaining one method of 1/16 interpolation;
Figures 17 a to r are waveform diagrams for explaining other methods of 1/16 interpolation, Figures 18 a, b, and 19 a,
b is a diagram illustrating an example of the circuit configuration of an actual detection element;
FIG. 0 is a diagram for explaining the operating principle of the present invention. 7, 7'... elemental piece, 8, 8'... detection element, 9...
...Magnetic lattice surface.

Claims (1)

[Claims] 1. A plurality of ferromagnetic elements having an anisotropic effect of magnetoresistance separated by a distance of nλ/2 (n is an integer other than 0) corresponding to the pitch λ of the magnetic grating of the magnetic scale 9. It has two components in which the pieces 7 and 7' are arranged substantially in parallel and each of the pieces is connected in series by a current path 10 and 10', each of which has one end of the component arranged in substantially parallel. These two components are connected in series, and an output terminal b is provided at the connection point at one end of the component, and current terminals a and c are provided at the other end of the two components, and the surface of each component and the magnetic lattice surface are connected. In a device for detecting a magnetic scale signal by facing each other face-to-face, the above two components are arranged at an interval of approximately (n/2+1/4)λ (n is an integer) to form a detection element, and A magnetic scale signal detection device, characterized in that a bias magnetic field is applied in substantially the same direction as each of the pieces, and a lead wire attachment portion of the detection element is disposed outside a magnetic lattice surface. 2. The magnetic scale signal detection device according to claim 1, wherein the current path is formed to be wider than the elemental piece. 3 A plurality of ferromagnetic pieces 7 and 7' having an anisotropic effect of magnetoresistance are arranged approximately parallel to each other at a distance of nλ (n is an integer other than 0) corresponding to the pitch λ of the magnetic grating of the magnetic scale 9. and each element is arranged in the current path 1.
It has two components connected in series at 0 and 10', one end of each of the components arranged substantially parallel is connected in series, and an output terminal b is provided at the connection point of one end of this component. In addition, in an apparatus for detecting a magnetic scale signal by providing current terminals a and c at the other ends of the two components and making the surfaces of the respective components and the magnetic lattice surface face each other, the two components described above. The elements are arranged at intervals of approximately (n+1/2)λ (n is an integer) to constitute a detection element, and each element is approximately
A magnetic scale signal detection device, characterized in that a bias magnetic field is applied in a 45° direction, and a lead wire attachment portion of the detection element is disposed outside a magnetic lattice plane. 4. The magnetic scale signal detection device according to claim 3, characterized in that two detection elements are arranged with an interval of λ/4. 5. Claim 3, characterized in that the elemental pieces are inclined at a predetermined angle with respect to a direction perpendicular to the longitudinal direction of the magnetic scale, and each elemental piece is arranged alternately at an interval that is an integral multiple of the magnetic lattice pitch. The magnetic scale signal detection device described. 6. The magnetic scale signal detection device according to claim 3, wherein the current path is formed to be wider than the elemental piece.