Self-induction-type position detector device for detecting object position
First Claim
1. A position detector device comprising:
- a coil section including at least one coil to be excited by an A.C. signal;
a magnetism-responsive member movable relative to said coil section, wherein relative positions between said magnetism-responsive member and said coil section vary in response to displacement of an object to be detected and impedance of said coil is caused to vary in response to a variation in the relative positions in such a manner that a voltage produced in said coil is caused to vary in response to a variation in the impedance of said coil during the variation in the relative positions within a predetermined range;
a reference-voltage generation circuit adapted to generate at least one predetermined reference voltage in the form of an A.C. signal; and
an arithmetic operation circuit coupled to said coil and reference-voltage generation circuit, said arithmetic operation circuit adapted to perform an arithmetic operation between said voltage produced in said coil and said predetermined reference voltage, so as to generate at least two A.C. output signals having predetermined cyclic amplitude functions as amplitude coefficients, the cyclic amplitude functions of the two A.C. output signals being different, in their cyclic characteristics, from each other by a predetermined phase.
1 Assignment
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Accused Products
Abstract
Single coil to be excited by a predetermined A.C. signal is provided, with no secondary coil being provided. Magnetism-responsive member is movable relative to the coil so that a self-inductance of the coil progressively increases or decreases in response to displacement of an object to be detected within a predetermined range and a voltage of the coil corresponding to the self-inductance is produced. Predetermined reference voltage is generated and subjected to analog operations with the coil output voltage, to thereby generate first and second A.C. outputs having, as amplitude coefficients, first and second cyclic amplitude functions correlated to the position to be detected. The position is detected on the basis of the phase component of the amplitude coefficient functions. Combination of two coils and one reference voltage may be employed. Further, a plurality of coil segments excitable by a same-phase signal are placed in series along the direction of displacement of the object so that a progressive increase or decrease occurs sequentially in the self-inductance of the coil segments as the magnetism-responsive member moves relative to the coil segments, and the voltage corresponding to the self-inductance is taken out from each of the coil segments. Performing analog arithmetic operations on combinations of the coil voltages produces first and second A.C. outputs having, as amplitude coefficients, first and second cyclic amplitude functions correlated to the position to be detected.
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Citations
34 Claims
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1. A position detector device comprising:
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a coil section including at least one coil to be excited by an A.C. signal;
a magnetism-responsive member movable relative to said coil section, wherein relative positions between said magnetism-responsive member and said coil section vary in response to displacement of an object to be detected and impedance of said coil is caused to vary in response to a variation in the relative positions in such a manner that a voltage produced in said coil is caused to vary in response to a variation in the impedance of said coil during the variation in the relative positions within a predetermined range;
a reference-voltage generation circuit adapted to generate at least one predetermined reference voltage in the form of an A.C. signal; and
an arithmetic operation circuit coupled to said coil and reference-voltage generation circuit, said arithmetic operation circuit adapted to perform an arithmetic operation between said voltage produced in said coil and said predetermined reference voltage, so as to generate at least two A.C. output signals having predetermined cyclic amplitude functions as amplitude coefficients, the cyclic amplitude functions of the two A.C. output signals being different, in their cyclic characteristics, from each other by a predetermined phase. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A rotary-type position detector device comprising:
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a coil section including at least one coil to be excited by an A.C. signal;
a magnetism-responsive member rotationally movable relative to said coil section, wherein relative rotational positions between said magnetism-responsive member and said coil section varies in response to rotational displacement of an object to be detected and impedance of said coil is caused to vary in response to a variation in the relative rotational positions between said magnetism-responsive member and said coil section in such a manner that a voltage produced in said coil is caused to vary in response to a variation in the impedance of said coil during the variation in the relative rotational positions within a predetermined rotational angle range;
a reference-voltage generation circuit adapted to generate a predetermined reference voltage; and
an arithmetic operation circuit coupled to said coil and reference-voltage generation circuit, said arithmetic operation circuit adapted to perform an arithmetic operation between said voltage produced in said coil and said predetermined reference voltage, so as to generate at least two A.C. output signals having predetermined cyclic amplitude functions as amplitude coefficients, the cyclic amplitude functions of the two A.C. output signals being different, in their cyclic characteristics, from each other by a predetermined phase. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
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19. A rotary-type position detector device comprising:
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a coil section including at least two pairs of coils to be excited by an A.C. signal, the coils in each of the pairs being positioned to be apart from each other by a distance corresponding to a predetermined rotational angle;
a magnetism-responsive member rotationally movable relative to said coil section, wherein relative rotational positions between said magnetism-responsive member and said coil section vary in response to rotational displacement of an object to be detected and impedance of each of said coils is caused to vary in response to a variation in the relative rotational positions in such a manner that a voltage produced in each of said coils is caused to vary in response to a variation in the impedance of said coil during the variation in the relative rotational positions within a predetermined rotational angle range, the voltages produced in the respective coils in each of the pairs presenting differential characteristics; and
a circuit coupled to said coil section, said circuit adapted to generate, for each of said two pairs of coils, an A.C. output signal having a predetermined cyclic amplitude function as an amplitude coefficient, by taking out a difference in the voltages produced in said respective coils, the cyclic amplitude functions of the A.C. output signals generated for said two pairs of coils being different in their cyclic characteristics by a predetermined phase.
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20. A position detector device comprising:
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a coil section including a plurality of coil segments to be excited by a predetermined A.C. signal, the coil segments being placed in series along a direction of displacement of an object to be detected;
a magnetism-responsive member movable relative to said coil section, wherein relative positions between said magnetism-responsive member and said coil section vary in response to displacement of the object to be detected and impedance of each of said coil segments is caused to vary in response to a variation in the relative positions in such a manner that a voltage produced in each of said coil segments is caused to progressively increase or decrease during a movement of said magnetism-responsive member from one end to another of each of said coil segments; and
an analog arithmetic operation circuit coupled to said coil section, said analog arithmetic operation circuit adapted to generate a plurality of A.C. output signals presenting amplitudes based on predetermined cyclic function characteristics corresponding to a position of the object to be detected, by taking out voltages of said coil segments and performing addition and/or subtraction on the taken-out voltages, the cyclic function characteristics defining the amplitudes of the plurality of A.C. output signals comprising cyclic functions of a same character that are different from each other by a predetermined phase. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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29. A position detector device comprising:
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a coil to be excited by a predetermined A.C. signal;
a magnetism-responsive member movable relative to said coil, wherein relative positions between said magnetism-responsive member and said coil vary in response to displacement of an object to be detected and impedance of said coil is caused to vary in response to a variation in the relative positions between said magnetism-responsive member and said coil in such a manner that a voltage produced in said coil is caused to progressively increase or decrease during a movement of said magnetism-responsive member from one end to another of said coil;
an impedance element to be supplied with the predetermined A.C. signal; and
a circuit coupled to said coil and said impedance element, said cuircuit adapted to receive the voltage produced in said coil and a voltage produced in said impedance element and generate a plurality of A.C. output signals presenting amplitudes based on predetermined cyclic function characteristics corresponding to a position of the object to be detected on the basis of the received voltages, the cyclic function characteristics defining the amplitudes of the plurality of A.C. output signals comprising cyclic functions of a same character that are different from each other by a predetermined phase.
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30. A position detector device comprising:
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a coil section including a plurality of coil segments to be excited by a predetermined A.C. signal, the coil segments being placed in series along a direction of displacement of an object to be detected;
a magnetism-responsive member movable relative to said coil section, wherein relative positions between said magnetism-responsive member and said coil section varies in response to displacement of the object to be detected and impedance of each of said coil segments is caused to vary in response to a variation in the relative positions between said magnetism-responsive member and said coil section in such a manner that a voltage produce in each of said coil segments is caused to progressively increase or decrease during a movement of said magnetism-responsive member from one end to another of each of said coil segments; and
an analog arithmetic operation circuit coupled to said coil section, said analog arithmetic operation circuit adapted to generate an A.C. output signal presenting an amplitude based on a predetermined cyclic function characteristic corresponding to a position of the object to be detected, by taking out voltages of said coil segments and performing addition and/or subtraction on the taken-out voltages.
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31. A position detector device comprising:
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a magnet; and
a coil section movable relative to said magnet and including a magnetic core extending along a direction of relative movement thereof to said magnet, said coil section being excitable by an A.C. signal and positioned in such a manner that magnetic saturation is produced at a predetermined portion of said magnetic core that is strongly affected by a magnetic flux from said magnet, and wherein one of said magnet and said coil section is placed on a given moving section whose position is to be detected as an object to be detected while other of said magnet and said coil section is fixed in position, and relative positions between said magnet and said coil section vary in response to displacement of said moving section, in response to which the predetermined portion of said magnetic core where the magnetic saturation is produced is shifted and said coil section generates an output signal corresponding to a shift in the predetermined portion of said magnetic core where the magnetic saturation is produced. - View Dependent Claims (32, 33, 34)
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Specification