JP2888074B2 - Magnetoresistive element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a linear displacement detecting device,
The present invention relates to a magnetoresistive element used for a rotation angle detecting device and the like.

[0002]

2. Description of the Related Art A conventional magnetoresistive element, for example, a four-element magnetoresistive element shown in FIG. 2 will be described. In the figure, reference numerals 1a to 1d denote meandering patterns of the magnetoresistive element,
The meandering patterns 1a and 1d have the same magnetic sensing direction and
The meandering patterns b and 1c have a magnetic sensing direction perpendicular to the meandering patterns 1a and 1d. When a magnetic field is applied to each of the meandering patterns 1a to 1d of the magnetoresistive element having such a configuration at an angle with respect to the longitudinal direction, the resistance value of each of the meandering patterns 1a to 1d is reduced according to the angle. Can be.

A magnetic rotation angle detecting device using a magnetoresistive element shown in FIG. 2 will be described with reference to a circuit diagram of FIG. In the figure, 1 is the magnetoresistive element of FIG. 2, 2a to 2h are operational amplifiers, 3 is a resistor, 4 is a capacitor, 5 is an LTR, 6 is a magnet, 7 is a main circuit including these (2 to 6), 8
Is an auxiliary circuit having the same configuration as the main circuit 7. In the magnetic rotation angle detecting device having such a configuration, when the portion of the magnet 6 rotates, the angle of the magnetic field applied to the position of the magnetoresistive element 1 changes. Meandering patterns 1a, 1d
And the meandering patterns 1b and 1c are perpendicular to each other and have different resistance values, so that Vs1 and Vs2, Vs3 and Vs
4, a potential difference corresponding to the rotation angle of the magnet 6 is generated. This potential difference is amplified by the operational amplifiers 2b to 2d and detected as the rotation angle of the magnet 6 by the main circuit 7 and the auxiliary circuit 8, respectively.

[0004]

As shown in FIG. 2, the conventional magnetoresistive element has the meandering patterns 1a to 1d. A slight temperature difference between the meandering patterns 1a to 1d. Meandering pattern (magnetic resistance element)
1a to 1d have a temperature characteristic, which causes a change in the resistance value. Further, the surrounding magnetic field is not always uniform, and there may be a local difference in the direction of the magnetic field. Of the meandering patterns 1a to 1d. Therefore, when detection is performed using the detection circuit of FIG. 3, if the surrounding environment between the meandering patterns 1 a to 1 d is in a uniform state, the outputs of the main circuit 7 and the auxiliary circuit 8 are similar. If the resistances of the meandering patterns 1a and 1d and the meandering patterns 1b and 1c are different due to the above-described factors, the outputs of the main circuit 7 and the auxiliary circuit 8 are different from each other. There is fear.

The present invention has been made to solve the above-mentioned problems, and at least the meandering pattern (magnetic resistance element) having the same magnetic sensing direction has substantially the same ambient temperature and magnetic field direction. Accordingly, it is an object to obtain a highly reliable magnetoresistive element which can prevent erroneous detection.

[0006]

According to a magnetoresistive element according to the present invention, two elements having magneto- sensitive directions perpendicular to each other are arranged on the left.
It is arranged in a meandering pattern symmetrically to the right.
Another two elements in left and right pairs in a different intricate meandering pattern
By arranging the positions, these positional differences are reduced.

[0007]

According to the present invention, a convoluted part having the same magnetic sensing direction is provided .
Because there is little positional difference between the two meandering patterns,
In the two meandering patterns having the same magnetic sensing direction, external factors such as temperature, magnetic field, and distortion can be uniformly received.

[0008]

FIG. 1 shows an embodiment of the present invention. In FIG, 1A to 1D are serpentine pattern <br/> over emissions of the magnetoresistive element, 1A, serpentine pattern of 1D is a rice cake and mutually intricate structure with the same magneto-sensitive direction, 1B, 1C of
The meandering pattern has a magnetic sensing direction perpendicular to the meandering patterns 1A and 1D and has a structure that is intricate with each other.

When used in the detection circuit of FIG. 3 in the same manner as in the prior art, the meandering patterns 1A and 1D and 1B and 1C are formed on the substrate even if the external environment such as temperature, magnetic field, and distortion are locally different.
Since they are formed in the same area , the resistance value changes are at the same level, and the same output can be obtained in the main circuit 7 and the auxiliary circuit 8.

[0010]

As it is evident from the foregoing description, together according to the present invention
Two elements with a perpendicular magnetic sensing direction
Another turn that is placed on the turn and intertwined with this meandering pattern
Another two elements are arranged symmetrically in a meandering pattern
As a result, even if there are local external factors, the effect of each meandering pattern can be kept the same,
The effect is obtained that erroneous detection can be prevented.

[Brief description of the drawings]

FIG. 1 shows a snake of a magnetoresistive element showing an embodiment of the present invention.
It is a figure of a row pattern arrangement .

FIG. 2 is a diagram showing a meandering pattern arrangement of a conventional magnetoresistive element.

FIG. 3 is a circuit diagram showing a rotation angle detecting device using the magnetoresistive element of FIG. 2;

[Explanation of symbols]

1A Magnetoresistance element ( meander pattern) 1B Magnetoresistance element ( meander pattern) 1C Magnetoresistance element ( meander pattern) 1D Magnetoresistance element ( meander pattern) 2a Operational amplifier 2b Operational amplifier 2c Operational amplifier 2d Operational amplifier 2e Operational amplifier 2f Operational amplifier 2g Operational amplifier 2h Operational amplifier 3 Resistance Body 4 Capacitor 5 LTR 6 Magnet 7 Main circuit 8 Auxiliary circuit

Claims (1)

(57) [Claims] 1. Two elements having magneto-sensitive directions perpendicular to each other.
Are arranged symmetrically in a meandering pattern, and the meandering pattern is
Different elements in left and right pairs with different meandering patterns
A magnetoresistive element, wherein the magnetoresistive element is disposed .