Magnetic position detecting apparatus

Abstract

In a position detecting apparatus 1 of the present invention, magnetic resistance circuits A and B of a first main circuit 10 include a reference magnetic resistance element +A, an even harmonic correction magnetic resistance element +A 3, being placed at a position shifted by (1 / 4)lambda or (3 / 4)lambda from the reference magnetic resistance element +A, with respect to a reference wave, and a third harmonic correction magnetic resistance element +A 2, being placed at a position shifted by (1 / 6)lambda from the reference magnetic resistance element, with respect to a reference wave, and magnetic resistance circuits A' and B' of a second main circuit 20 include the magnetic resistance circuit of the second main circuit 20 includes a reference magnetic resistance element +A' 1, a fifth harmonic correction magnetic resistance element +A' 2, being placed at a position shifted by (1 / 10)lambda from the adjacent magnetic resistance element, with respect to a reference wave and a fifth harmonic correction magnetic resistance element +A' 2, being placed at a position shifted by (4 / 15)lambda from the reference magnetic resistance element +A' 1, with respect to a third harmonic wave.

Description

technical field [0001] The present invention relates to a position detection device that detects the position of a driven body that moves linearly or rotates, and particularly relates to a position detection device that utilizes magnetism. Background technique [0002] As such a position detection device, Patent Document 1 discloses a structure in which one and the other magnetoresistive circuits formed by connecting a plurality of magnetoresistive elements in series are formed into comb teeth, and one and the other magnetoresistive circuits are formed The resistance circuits are arranged laterally side by side along the magnetic pole arrangement direction. [0003] Patent Document 2 also discloses a technique of forming a groove on the magnetized surface to adjust the output waveform of the reluctance circuit from the reference position. [0004] [Patent Document 1] Japanese Patent Publication No. 54-41335 [0005] [Patent Document 2] JP-A-7-4987 [0006] However, in the...

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Problems solved by technology

[0006] However, in the technology of Patent Document 1, since a plurality of magnetoresistive circuits of the position detection device are arranged side by side in the magnetic pole arrangement direction, when one magnetoresistive circuit has a plurality of magnetoresistive elements, or a plurality of magnetoresistive circuits are provided In the case of , there is a problem that the circuit length in the direction of the magnetic pole arrangement is long, the size of the device is large, and the resolution of the output waveform is low.

[0007] In Patent Document 2, when a plurality of magnetoresistive circuits are provided, the same problem as that of Patent Document 1 arises that the size of the position detection device increases. Image 6 As shown in (b), in the position detection device of a rotating driven body, if a longer length of the position detection device 21 in the width direction (magnetic pole arrangement direction) is adopted, the problem that occurs is that the width of the position detection device The intensity of the magnetic field received by the two ends 21a of the direction is reduced due to the position deviation, and the resolution of the output waveform is reduced

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