JPS5941882A - Magnetism sensitive element - Google Patents

Abstract

PURPOSE:To obtain highly accurate position detecting signals, characterized by the constitution wherein ferromagnetic metal thin film magnetoresistance elements are divided into a plurality of axial symmetric or point symmetric units and neighboring polygonal line patterns constituting the magnetoresistance elements between the units are arranged at a specified angle. CONSTITUTION:The magnetoresistance elements between ferromagnetic metal magnetoresistance element units A-H are constituted by neighboring polygonal line patterns PA-PH. The patterns are arranged at, e.g., 30 deg. and 60 deg. alternately. The parts between an output terminals OUT1 and OUT4 are connected by jumper wires J1 and J4, and a bridge is formed. Then two phase outputs, whose phases are different by 120 deg., are obtained. Or signals, whose phases are different by 120 deg. one another, are formed, and three phase position signals are obtained from one magnetism sensitive element. Or the neighboring polygonal line patterns between the units are arranged at 45 deg., so that two phase outputs, whose phases are different by 90 deg. are obtained.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to a magnetically sensitive element, particularly the magnetoresistive effect of a ferromagnetic metal thin film? This invention relates to an improved VC using a magnetoresistive element.

BACKGROUND ART AND PROBLEMS There is a Hall element, for example, as a conventional magnetic sensing element, which is widely used for detecting the rotor position of a brushless motor as shown in FIG. In the same figure, Hall elements 1 to 3 are arranged on the motor outer wall 4 at angular positions that differ by about 120 degrees from each other, and the electric currents differing in phase by 120 degrees according to the rotation of the magnet 60 attached to the motor shaft 5. A signal is obtained from each Hall element. The position of the rotor and its rotational direction are detected from the signals of these three types, but if such conventional magnetic sensing elements are used, three Hall elements (at least two) are required. It is inevitable that the cost will be high.

Moreover, the mounting accuracy of each Hall element is determined to be the precision of the phase of the element output, and very strict J1'y and mounting accuracy are required. Furthermore, as the outer wall of the motor becomes smaller, incorporating a plurality of Hall elements 2 into it becomes technically quite difficult.

In addition to the above-mentioned Hall element, conventional magnetic sensing elements include Ni
-Magnetoresistance effect of ferromagnetic metal thin film of Co or Ni-Fe? As the magnetoresistive element used, for example, a broken line pattern as shown in Fig. 2? A ferromagnetic metal thin film magnetoresistive element having a three-terminal structure is known.

As is well known, this element generates vibrations every 172 rotations of the magnetic field H =■
o=base 20KVCC5in2θ voltage output? Occur.

However, this element also has the same problems as the pole element in applications such as position detection.

OBJECTS OF THE INVENTION An object of the present invention is to solve the problems of the prior art and provide a magnetic sensing element suitable for use in detecting the position of a rotating body, etc.

Summary of the Invention In order to achieve the above-mentioned object, the magnetic sensing element of the present invention consists of a ferromagnetic metal thin film magnetoresistive element divided into a plurality of line-symmetric or point-symmetric units, and the magnetoresistive element between each unit.
A key feature is that the adjacent broken line patterns forming the structure are arranged at a predetermined angle.

EXAMPLES The present invention will be explained with reference to the following examples shown in the drawings.
In Fig. 3, A~1] are ferromagnetic magnetoresistive element units divided into eight symmetrical units, and adjacent broken line patterns PA and pH that constitute the magnetoresistive elements between each unit are as shown in the figure. They are arranged at angles of 30' and 60'' from each other.

0[JT1 to 0tJT 4 is an output terminal, ■ and G are voltage application terminals and ground terminals, for example, output terminal 0[JT
1 and (JUT 4? Jumper m J 1 and J
4 to create a bridge configuration.

4A is an equivalent circuit of the magnetically sensitive element shown in Fig. 3, and if the output voltage of each terminal is vV1 to 4, the magnetic field applied to the element is /2 rotation button as shown in Fig. 5, l B = VI
V2 = K'V((s in 29 and me -V3
−V4= K'VCos in (2e −/3 yr
) can be obtained with two phase outputs having a phase difference of 120' from each other. Therefore, these two signals 〆By j'o
It is easy to generate signals 2 having a phase difference of 12♂ from each other using a circuit, and thus three phase detection signals can be obtained from one magneto-sensitive element.

FIG. 6 shows another embodiment of the invention in which the adjacent fold pattern between each unit is arranged at an angle of <45" as shown. This element is also configured in a bridge as shown in FIG. If you take out v5 ~ ■81 yen, then s, = V5 - V6 = KVo, 5inze <
Two-phase output 'DP'K with 90 different phases can be obtained.

Regarding the arrangement of the magnetoresistive element units, as shown in Fig. 8, it is a regular square shape. It may be divided into eight equal parts, and the number of unit divisions is not limited to eight, and the angle of the fold line pattern between units can be arbitrarily set according to the ITI.

As described above, according to the present invention, since the element units are symmetrical, a uniform magnetic field acts on each unit, and therefore uniform output of each phase can be obtained.

Furthermore, by consolidating multiple units into one chimp, it can be easily downsized and the wiring process becomes easier.

Furthermore, each phase output can be a sine wave with little distortion, and it also has a two-phase output arrangement. The Kh degree is good, and if a saturation magnetic field is applied, the arrangement of the elements does not need to be as precise as in the past.

Although it is not necessary for each element unit to be arranged in a bridge configuration, if the bridge configuration is used, a zero-based output can be obtained, which is particularly effective for applications such as position detection.

[Brief explanation of drawings]

Is Figure 1 a conventional Hall element? -g of the position detection device used
FIG. 2 is a schematic diagram showing an example of a conventional magnetoresistive element, FIGS. 3(a) and (b) are schematic diagrams showing an embodiment of the present invention, and FIG. is an example equivalent circuit diagram,
FIG. 5 is a diagram of the output waveform, and FIG. 6(a). (b) is a schematic diagram showing another practical HLQ column of the present invention, FIG. 7 is an equivalent circuit diagram of 7, and FIG. 8 is a schematic diagram showing another embodiment of the present invention.
FIG. A-H... Magnetoresistive element unit, PA" pi.
... Broken line pattern, 0tJT1 to 01JT4... Output terminal, ■... Voltage application terminal, G... Ground terminal. Figure 1 - 387 - Figure 4 Figure 5 (0) Figure 6 (b) Figure 8 Procedural amendment (method) 1. Indication of the case 1982 Patent Application No. 153043 2. Name of the invention Element 3. Relationship with the case of the person making the amendment Patent applicant address name (21B) Sony Corporation 4, agent address 105 Address Shiba 3-chome Building, 3-2-14 Shiba, Minato-ku, Tokyo November 1980 30 days (shipment date) Explanation 1 The brief explanation column of drawing 1 and (87 Drawing 7, contents of amendment (as per IJ appendix (2+ +, as in page 5, line 1 J, 1 of the specification of application 8A)) 11 Ibid., page 7, line 2 Y, “Schematic diagram showing Relin, No.
The figure is an output waveform diagram of the embodiment of FIG. 6. ”. (3) Add attached Figure 9. 389-

Claims (4)

[Claims] (1) Consists of a ferromagnetic metal thin film magnetoresistive element divided into a plurality of M-symmetric or point-symmetric units and formed in a broken line pattern within each unit, and the broken line pattern of adjacent magnetoresistive elements between each unit is A magnetic sensing element characterized in that it is arranged at a predetermined angle. (2) The magnetic sensing element according to claim 1, wherein the output of each unit is configured as a bridge. (3) The magnetically sensitive element according to claim 1, wherein the element is equally divided into 8 units, and the angle is 60'. (4) The magnetic sensing element according to claim 1, wherein the element is equally divided into eight units, and the angle is 45 degrees.