JP3839449B2 - Position detection device - Google Patents

Description

  The present invention relates to a position detection device (hereinafter referred to as a cordless position detection device) that does not require wiring cords for power supply or signal transmission from a fixed portion to a movable portion side.

  Rotation position detection devices include light transmission encoders, light reflection encoders, rotary transformer type resolvers, variable reluctance type resolvers, gear detectors that detect rotational positions of gears using a magnetoresistive element, etc. Although detection devices have been put into practical use, there are problems such as being vulnerable to dust, low resolution, and expensive.

  For example, as described in Japanese Patent No. 2513683, the linear position detection device uses an electromagnetic induction type cordless position detection device as a part of the coordinate input device, but cannot detect the position in real time. It is not suitable for machine positioning devices.

  As a cordless position detector, a variable reluctance linear resolver has been proposed as described in, for example, Japanese Patent Application Laid-Open No. 2000-314604, but a large number of core magnetic poles and windings corresponding to a detection length are provided on the fixed part side. Is expensive.

  As a type that detects the rotational position, for example, a substrate type resolver as described in JP-A-2001-314069 is known. The resolver described in this document includes a stator substrate (1) on which a stator sin winding pattern (20) and a stator cos winding pattern (21) are formed, and the stator substrate facing the stator substrate (1). (1) is a substrate type resolver comprising a rotor substrate (5) that is rotatably arranged with a gap and a rotor winding pattern (30) provided on the rotor substrate (5). (1) consists of a configuration in which an excitation winding pattern (4) formed in a ring shape is disposed at the outer peripheral position of the stator sin winding pattern (20) and the stator cos winding pattern (21). Is a substrate type resolver. The rotor winding pattern (30) is connected or directly short-circuited at both ends by a capacitor (C), and the magnetomotive force generated from the rotor winding pattern (30) is substantially sin-wave. Is formed.

  However, since the excitation winding pattern (4) of the stator substrate described in this document is formed in a ring shape at the outer peripheral position of the sin winding pattern (20) and the stator cos winding pattern (21), the excitation winding pattern (4) It is difficult to improve detection accuracy because the magnetic field strength is low and the output voltage is low. Further, since the excitation winding pattern does not have a function to cancel external common noise linked to the excitation winding pattern, there is a problem that the excitation winding pattern is easily affected by noise.

  Further, JP-A-8-313295 discloses a transducer read head 100 having a transmitter winding 102 and a receiver winding 104 composed of loops 106 and 108 as a linear position detecting device. . However, according to the operating principle of the transducer described in this document, the excitation transmitter winding is formed in a loop around the receiver winding for detection. The magnetic flux density is insufficient and the magnetic coupling with the receiver winding is also insufficient. Further, similarly to the above, the transmitter winding 102 does not have a function of canceling the external common noise linked to the transmitter winding, so that there is a problem that it is easily affected by noise.

Japanese Patent No. 2513683 JP 2000-314604 A JP 2001-314069 A JP-A-8-313295

  An object of the present invention is a position detection device (hereinafter referred to as a cordless position detection device) that does not require power supply from the fixed portion to the movable portion side or wiring cords for signal transmission, and has a high detection response speed. It is an object of the present invention to provide an electromagnetic induction type cordless position detection device that can be reduced in size and thickness, is inexpensive, and is useful for highly accurate linear position detection and rotational position detection.

(1) An exciting coil formed so that a normal winding and a reverse winding are alternately displayed on the first plane in units of at least one pitch in a certain direction;
A detection coil formed on a second plane at a position shifted by a half pitch from the excitation coil, so that forward and reverse windings appear alternately in at least one pitch unit in the same direction as the excitation coil;
A resonance coil having a resonance capacitor connected in parallel to the third plane;
At least the excitation coil in the first plane and the detection coil in the second plane have magnetic coupling;
The third plane is spaced apart from the first plane and the second plane via a space, and is freely movable in a detection coil forming region serving as a detection region. The detection coil and the resonance coil can be magnetically coupled,
A position detection device that obtains a position detection voltage from the detection coil according to the position of the resonance coil.
(2) The excitation coil on the first plane and the detection coil on the second plane are formed to extend in one direction, and the third plane moves so as to slide in this formation region. Position detector.
(3) The position detection according to (1) above, wherein the excitation coil on the first plane and the detection coil on the second plane are formed in a rotationally symmetrical manner, and the third plane moves so as to rotate in this formation region. apparatus.
(4) The position detection device according to any one of (1) to (3), wherein the excitation coil and the detection coil are formed by two zigzag curves whose one ends are closed.
(5) The position detection device according to any one of (1) to (4), wherein the excitation coil and the detection coil are formed by connecting discontinuous spiral coils in series.
(6) The position detection device according to any one of (1) to (5), wherein the resonance capacitor portion of the resonance coil is short-circuited.
(7) The position detection device according to any one of (1) to (4), wherein a metal conductor plate is used instead of the third plane resonance coil.
(8) The position detection device according to any one of (1) to (7), wherein the first plane and the second plane are configured by a laminated substrate.
(9) Position detection according to any one of (1), (2), (4) to (8), wherein the first plane and the second plane are provided for a plurality of detection axes and multi-axis position detection is performed. apparatus.

  According to the present invention, an electro-magnetic circuit can be configured only by a printed board and a capacitor having no iron core or windings, so that an inexpensive, small and thin cordless position detecting device can be realized. In addition, since the excitation coil and the detection coil each form a plurality of loops and are strongly magnetically coupled, and the detection loop and the excitation loop are shifted by a half pitch, the position detection signal of the conventional position detection device Is 2P, which is twice the coil pitch P, whereas the period of the present invention is 1P and the resolution is doubled. Therefore, a high-output and high-precision cordless position detection device can be realized with a simple configuration. Further, since a mechanism for canceling external noise is provided in the excitation loop and the detection loop, a cordless position detection device that is resistant to noise can be realized.

  The position detection device of the present invention includes an excitation coil formed so that forward winding and reverse winding are alternately displayed on the first plane in units of at least one pitch, and the excitation coil is half pitch on the second plane. There is a detection coil formed so that the forward winding and the reverse winding appear alternately in at least one pitch unit at a shifted position, and a resonance coil having a resonance capacitor connected in parallel on the third plane. And at least the first plane excitation coil and the second plane detection coil have magnetic coupling, and the first plane and the second plane are spaced apart from each other through a space. The resonance coil can be freely moved in the detection coil forming region as the detection region, and can be magnetically coupled to the excitation coil and the detection coil depending on the moving position. It is intended to obtain the position detection voltage.

  Here, the first plane, the second plane, and the third plane do not need to be planes defined in terms of geometry, and have a certain thickness that can accommodate a conductor pattern formed on each plane. And a plate-like structure composed of front and back sides as necessary. More specifically, it is a resin plate-like body capable of forming an electronic circuit, and a material used for a prepreg, a printed board or the like is preferable. The circuit pattern can be easily configured by patterning a metal foil such as a copper foil or an aluminum foil.

  The excitation coil forms a magnetic field for generating an electromotive force from the detection coil by the resonance coil. The exciting coil is formed by, for example, two zigzag curves with one end closed, and a loop formed by being surrounded by the two zigzag curves is generated with just a normal winding and a reverse winding, or alternately with a normal phase and a reverse phase. It is like that. Alternatively, the forward spiral pattern and the reverse spiral pattern may be alternately connected in series. The exciting coil is formed and arranged along the measurement region of the position detection device. A loop formed by a zigzag curve or the like is formed so that a normal winding and a reverse winding appear alternately in one pitch unit corresponding to at least one loop, and covers a measurement area with a pair of forward and reverse loops as a minimum unit. The number of loops that can provide a sufficient excitation magnetic field to the detection coil is formed. For this reason, the loop is preferably formed by one pitch or more than the detection coil. The excitation coil can be formed on the front and back surfaces of a printed circuit board or the like that forms a plane as described above.

  The detection coil generates a predetermined detection signal from the balance between the magnetic field from the excitation coil and the magnetic field generated by the resonance coil. This detection signal is normally output as an alternating voltage. For example, the detection coil is formed by two zigzag curves whose ends are closed like the excitation coil, and the loop formed by being surrounded by the two zigzag curves is just the normal winding and the reverse winding, and the normal phase and the reverse phase are It is designed to occur alternately. Or you may comprise using a spiral coil as mentioned above. This detection coil is formed and arranged along the measurement region in the same manner as the excitation coil. A loop formed by a zigzag curve or the like is formed with a half-pitch shift with respect to the loop of the exciting coil, and is formed by the number of loops that can cover the measurement region with one set of forward and reverse loops as a minimum unit. The detection coil and the excitation coil are normally fixed, and the positional relationship between the excitation coil and the detection coil is also fixed. The detection coil can also be formed on the front and back surfaces of a printed circuit board or the like that forms a plane as described above. Moreover, you may form an exciting coil and a detection coil in the printed circuit board on which the some structure layer was laminated | stacked.

  The resonance coil receives a magnetic field from the exciting coil, generates an electromotive force therein, resonates with a resonance capacitor connected in parallel, and generates a magnetic field generated from the resonance current or the power itself. Note that the resonance capacitor can be omitted. Similarly to the excitation coil, this resonance coil is also formed by two zigzag curves closed at one end, for example, and a loop formed by being surrounded by two zigzag curves is just a normal winding and a reverse winding. It is designed to occur alternately. Or you may comprise with a spiral coil similarly to the above. The resonance coil has a basic unit of a pair of forward and reverse loops or a single loop of forward and reverse. Usually, the resonance coil is composed of only this basic unit. However, if necessary, additional loops can be added.

  Furthermore, the first plane and the second plane may have a plurality of detection axes such as an XY axis, and multi-axis position detection may be performed. Alternatively, the first plane, the second plane, and the third plane may be shaped corresponding to the rotating body, and the excitation coil, detection coil, and resonance coil may be formed rotationally symmetrically. By setting it as such a shape, the rotation position of a rotary body is detectable.

[First embodiment]
Next, the position detection apparatus of the present invention will be described more specifically with reference to the drawings. FIG. 1 is a plan view showing a basic structure (also referred to as a first aspect) of a position detection device of the present invention.

  In the figure, an excitation loop pattern 4 serving as an excitation coil is formed on the first plane 1. The excitation loop pattern 4 is formed on the surface of the base 11 and has one pitch 1P and a width (vertical) s1 indicated by a solid line in one direction in a trapezoidal zigzag, in this example from the start in the longitudinal (lateral) direction. An outward curve pattern 41 extending to the end, and a return curve pattern 42 formed on the back surface of the substrate 11 and returning from the end to the start end in a zigzag indicated by a dotted line, and the outward curve pattern 41 and the return curve pattern 42 are formed at the end. Connected and both conductor lines are closed. The forward curve pattern 41 and the backward curve pattern 42 form loop areas C11 to C15 surrounded by a zigzag curve. In the figure, the solid line represents the pattern on the substrate surface side, the broken line represents the pattern on the back surface side, and both are connected by through holes or via holes (the same applies hereinafter).

  An excitation power source 7 is connected to the excitation loop pattern 4 via nodes n1 and n2, and an alternating current having a predetermined frequency and voltage is supplied. The frequency of the excitation power supply is not particularly limited, but is preferably 100 K to 1000 KHz, and the excitation current is preferably about 10 to 100 mA.

  A detection loop pattern 5 serving as a detection coil is formed on the second plane 2. Similarly to the excitation loop pattern 4, this detection loop pattern 5 is also formed on the surface of the base 12 and has one pitch 1P indicated by a solid line and a width (vertical) s1 in a trapezoidal zigzag in one direction, in this example, a longitudinal direction. An outward curve pattern 51 extending from the start end to the end in the (lateral) direction and a return curve pattern 52 formed on the back surface of the base 12 and returning from the end to the start end in a zigzag indicated by a dotted line, and the outward curve pattern 51 at the end. And the return curve pattern 52 are connected, and both conductor lines are closed. The forward curve pattern 51 and the return curve pattern 52 form loop areas C21 to C24 surrounded by a zigzag curve. The detection loop pattern 5 is shifted in the longitudinal direction of 1/2 pitch with respect to the excitation loop pattern 4, that is, in the loop forming direction, and is shifted by a half pitch.

  The first plane 1 and the second plane 2 are normally fixed, and the positional relationship of the second plane 2 with respect to the first plane 1 is also fixed. The first plane 1 and the second plane 2 can be formed by separately preparing a base, but can also be integrated. When integrated, the first plane 1 and the second plane 2 may be stacked or stacked, but a short circuit between the excitation loop pattern 4 and the detection loop pattern 5 formed on these planes is prevented. Therefore, it is necessary to provide an insulating layer between them. This insulating layer may be air, but is preferably a laminate using the same material as the base constituting the first plane 1 and the second plane 2.

  Specifically, as shown in FIG. 2, between the first substrate 11 constituting the first plane 1 and the second substrate 12 constituting the second plane 2, these substrates 11, An insulating substrate 14 made of the same material as 12 is provided to form a laminated substrate. Here, a conductor layer 4a forming the excitation loop pattern 4 is vertically arranged on the first substrate 11, and a conductor layer 5a forming the detection loop pattern 5 is vertically arranged on the second substrate 12. Yes. The insulating substrate 14 prevents the conductor layers 4a and 5a from being short-circuited. Lamination of the substrate can be easily performed by a known method such as thermocompression bonding.

  A resonance loop pattern 6 serving as a resonance coil is formed on the third plane 3. Similarly to the excitation loop pattern 4, the resonance loop pattern 6 is also unidirectional in a trapezoidal zigzag with a size 1/2 pitch 1 / 2P, a width (vertical) s1, and a pitch 1P as indicated by a solid line. Is composed of an outward curve pattern 61 extending from the start end to the end in the longitudinal (lateral) direction and a return curve pattern 62 returning from the end to the start end in a zigzag indicated by a dotted line, and is formed on the front and back surfaces of the substrate 13 at the end. The forward curve pattern 61 and the return curve pattern 62 are connected, and both conductor lines are closed. The forward curve pattern 61 and the backward curve pattern 62 form two loop areas C31 and C32 surrounded by a zigzag curve. Between the loop areas C31 and C32, there is 1 / 2P, and a straight return curve pattern 62 and a forward curve pattern 61 are simply arranged in parallel. The open end of the resonance loop pattern 6 is connected to the resonance capacitor C1 via nodes n5 and n6.

  The capacitance of the resonance capacitor varies depending on the excitation frequency and the inductance of the resonance coil, but is preferably about 0.01 to 0.1 μF, for example. The width of the resonance loop pattern is 1 / 2P in this example. However, if the pitch of each loop is 1P, the width is not particularly limited, and may be 1P like each of the above loops. However, other widths may be used.

  The third plane 3 is either the first plane 1 or the second plane 2, or both are arranged apart from each other in the stacking direction. And it can slide or move in parallel with respect to these planes freely in the measurement region, that is, the formation region of the excitation coil or the detection coil. Specifically, as shown in FIG. 2, for example, a third body 9 having conductor layers 6a on the upper and lower sides of the substrate 13 at positions separated from each other in the stacking direction of the stacked body 9 having the first plane and the second plane. A plane 3 is arranged. Although a mechanism for sliding or moving is omitted in this specification, it can be easily achieved by a known method in this type of field.

  Next, the operation of the position detection apparatus of this illustrated example will be described.

  First, it is assumed that the third plane 3 does not exist or exists outside the measurement region. Now, when the excitation current i flows from the excitation power source 7 to the excitation loop 4 in the direction of the solid line arrow, the loop areas C11, C13, and C15 of the excitation loop pattern 4 are viewed from below on the paper surface as indicated by the mark in FIG. A magnetic flux is generated vertically upward, and a magnetic flux is generated vertically in the areas C12 and C14 from the top to the bottom on the paper surface as indicated by a cross.

  At this time, the magnetic fluxes in the loop areas C11 and C12 are evenly linked in the loop area C21 of the detection loop pattern 5 and are canceled because they are opposite to each other, and no electromotive force is generated. Similarly, no electromotive force is generated in the loop areas C22, C23, and C24, and therefore no detection voltage that is an AC induced voltage is generated between the nodes n3 and n4 of the detection loop pattern. Similarly, when the exciting current i flows in the direction of the dotted line, only the directions of the magnetic fluxes are reversed, and no detection voltage is generated.

  Next, as shown in FIG. 2, the third plane 3 is on the start side of the excitation loop pattern, and the loop areas C31 and C32 of the resonance loop pattern 6 overlap with the loop areas C11 and C12 of the excitation loop pattern 4. Suppose you are.

  At this time, as shown in FIG. 1, when the excitation current i flows in the excitation loop pattern 4 in the direction of the solid line arrow, the loop area C11 of the resonance loop pattern 6 on the third plane 3 is moved to the loop area C11 of the excitation loop pattern 4. The magnetic flux is interlinked, and the magnetic flux in the loop area C12 is interlinked in the loop area C32 to generate an electromotive force in the direction of the solid arrow. On the other hand, when the excitation current i flows in the direction of the dotted arrow, the directions of the magnetic fluxes in the loop areas C11 and C12 are reversed, and similarly, an electromotive force in the direction of the dotted arrow is generated in the resonance loop pattern by the electromagnetic induction operation.

  Since the direction of the excitation current to which alternating current is applied periodically changes, alternating current also flows through the resonance loop pattern 6 and resonates by the resonance capacitor C1. When a capacitor having an appropriate constant is selected as the resonance capacitor C1, the opposing interval is narrowed and the position of the resonance loop pattern 6 and the width s1 of the excitation loop pattern 4 are aligned to strengthen the magnetic coupling, a large resonance current flows. Since the resonance loop pattern 6 is also magnetically coupled to the detection loop pattern, the magnetic flux of the resonance loop pattern 6 generated by the resonance current is linked to the detection loop pattern 5 and is superimposed on or canceled by the magnetic flux generated by the excitation loop pattern. As a result, the balance between the canceling effects is lost and a detection voltage is induced.

  At the origin og position on the third plane 3 as shown in FIGS. 1 and 2, the loop areas C31 and C32 of the resonance loop pattern 6 are magnetically coupled only to the loop areas C11 and C12 of the excitation loop pattern, respectively. The electromotive forces of area C31 and area C32 are added, and the maximum resonance current flows, and electromagnetically induces the detection loop pattern 4. Assuming that the detection voltage having the same phase as the excitation power source is the positive phase and the detection voltage having a phase different by 180 ° is the reverse phase detection voltage, as shown in FIG. 3, the maximum detection of the positive phase is performed at the position of the third plane 3 of the origin og. A voltage is induced and output to nodes n3 and n4 of the detection loop pattern.

  Next, when the third plane 3 is moved in the right direction on the paper surface and the width s1 direction is left as it is and is translated in parallel with the same interval, the loop area C31 of the resonance loop pattern 6 and the loop area C12 are moved in accordance with the movement. Is also magnetically coupled to the loop area C13. For this reason, the resonance current is also canceled and reduced by the amount of magnetic coupling with the loop areas C12 and C13, the magnetic flux that electromagnetically induces the detection loop pattern is reduced, and the detection voltage is also reduced.

  Further, when the third plane 3 moves to the right from the origin og to a position of 1 / 4P, the loop area C31 of the resonance loop pattern 6 is magnetically coupled equally to the loop areas C11 and C12, and the loop area C32 is also the loop area C12, Since it is magnetically coupled equally to C13, the electromotive forces in the loop areas C31 and C32 are canceled out, the resonance current becomes zero, and the detection voltage becomes zero.

  When the third plane 3 moves further to the right, the loop area C31 of the resonance loop pattern 6 becomes more magnetically coupled to the loop area C12 than the loop area C11 as the movement moves, and the loop area C32 also has the loop area C13 than the loop area C12. And a large amount of reverse-phase resonance current flows. The loop area C31 is magnetically coupled to the loop area C21 of the detection loop pattern 4 and the loop area C32 is magnetically coupled to the loop area C22. Therefore, a reverse-phase detection voltage is induced and becomes larger as it moves to the right.

  At the position where the third plane 3 is moved 1 / 2P from the origin og, the loop area C31 is magnetically coupled only to the loop area C12, and the loop area C32 is magnetically coupled only to the loop area C13. Since the area C31 is magnetically coupled only to the loop area C21 of the detection loop pattern 4 and the loop area C32 is magnetically coupled only to the loop area C22, the maximum detection voltage in reverse phase is output.

  When the third plane 3 moves further to the right, the area C31 of the resonance loop pattern 6 is added to the loop area C21 of the detection loop pattern 4, and the loop area C32 is added to the loop area C22. Magnetic coupling occurs, the magnetic fluxes of the loop area C22 and the loop area C23 are canceled out, and the detection voltage of the reverse phase induced in the detection loop pattern 4 decreases.

  Further, when the third plane 3 moves to the right to the position of 3 / 4P, the loop area C31 of the resonance loop pattern 6 is magnetically coupled equally to the loop areas C21 and C22 of the detection loop pattern 4, and the loop area C32 is also the loop area. The magnetic coupling is equal to C22 and C23, the magnetic fluxes cancel each other, no detection voltage is induced in the detection loop pattern 4, and the detection voltage becomes zero.

  In this way, when the third plane 3 is provided with a predetermined distance from the first plane 1 and the second plane 2 and moved parallel to each other, the movement of the third plane is performed as shown in FIG. Corresponding to the quantity, a detection voltage that changes in a sine wave shape with a period P is output.

  In the above example, the excitation loop pattern 3, the detection loop pattern 4, and the resonance loop pattern 6 are formed by a single loop, but may be configured by a plurality of loops.

  Further, when both ends of the resonance capacitor C1 are short-circuited, an eddy current flows instead of the resonance current, so that the detection loop pattern 5 corresponds to the movement of the movable printed board which is the third plane 3 as in the case of the resonance current. The magnetic flux in the loop areas C21 to C24 changes, and a detection voltage that changes like a sine wave as in FIG. Further, when a metal conductor plate having the same shape as the loop area of the resonance loop pattern 6 is formed and arranged at a pitch P instead of the coil in the loop area, an eddy current flows through the metal conductor plate and similarly changes into a sine wave shape. The detection voltage is output.

As described above, it can be seen that this basic operation loop can detect a voltage that changes in a sine wave shape corresponding to the linear movement of the movable part without any wiring cords from the fixed part to the movable part.

[Second embodiment]
Next, the second aspect of the present invention will be described. FIG. 4 is a plan view showing a second aspect of the present invention. In this embodiment, the excitation loop pattern 4, the detection loop pattern 5, and the resonance loop pattern 6 are configured by a sine wave zigzag curve instead of the trapezoidal zigzag curve as in the first embodiment. In this example, the loop areas C31 and 32 formed by the resonance loop pattern 6 are changed in size in the pitch direction from 1 / 2P of the first mode to 1P. Other constituent elements are the same as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

  In the second aspect having such a configuration, when the third plane moves in the same manner as in the first aspect, a sinusoidal detection voltage as shown in FIG. 5 is obtained.

[Third Aspect]
Next, a third aspect of the present invention will be described. FIG. 6 is a plan view showing a third aspect of the present invention. In this aspect, the detection loop pattern 5 on the second plane 2 has redundant loops C2a and C2b each having a size (length) 1 / 2P added to the start end side and the end end side thereof. Thus, the detection effective length can be expanded by adding redundant loops C2a and C2b. Further, when the redundant loop C16 is added to the excitation loop pattern 4, the number is increased by one as compared with the first mode to be an even number, and it is possible to strengthen against disturbance factors such as noise.

  That is, when the excitation loop pattern 4, the detection loop pattern 5 and the resonance loop pattern 6 are formed so as to be an even number of loop areas, and the directions of generated magnetic fluxes in adjacent areas are alternately different, Since the loop has a function to cancel the magnetic flux, for example, even if the magnetic flux of the external common noise is interlinked, the external common noise can be canceled in each loop, so that a position detection device that is extremely resistant to noise can be realized. .

  Even in this example, the loop areas C31 and C32 formed by the resonance loop pattern 6 have a size of 1P. Even if such a resonance loop pattern is adopted, the same as in the first mode of FIG. Since the magnetic coupling operation is performed, a sinusoidal detection voltage as shown in FIG. 7 is output. The number of loop areas of the resonance loop pattern may be one, or a plurality of may be used in order to increase the amplitude of the detection voltage.

  Other constituent elements are the same as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

[Fourth aspect]
Next, a fourth aspect of the present invention will be described. FIG. 8 is a plan view showing a fourth aspect of the present invention. In this aspect, the excitation loop pattern 4 on the first plane 2, the detection loop pattern 5 on the second plane 2, and the resonance loop pattern 6 are formed by connecting discontinuous spiral coils. That is, in FIG. 8, the excitation loop pattern 4 is formed by connecting spiral coils 401 to 405 having the same rectangular shape and wound in widths s1 and s2 alternately in series so that the winding directions are different. Yes. Similarly, the detection loop pattern 5 is formed by spiral coils 501 to 504, and the resonance loop pattern 6 is formed by spiral coils 601 and 602. Since these loop patterns 4, 5, and 6 perform the magnetic coupling operation similar to the excitation loop pattern 4, the detection loop pattern 5, and the resonance loop pattern 6 of FIG. 1, a sine wave detection voltage as shown in FIG. Is output. Further, the spiral coil need not be rectangular, and may be circular.

  Other constituent elements are the same as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

[Fifth aspect]
Next, a fifth aspect of the present invention will be described. FIG. 10 is a plan view showing a fifth aspect of the present invention. In this aspect, the excitation loop pattern 4 on the first plane 1 in the third aspect, the detection loop pattern 5 on the second plane 2 and the resonance loop pattern 6 on the third plane 3 in the first aspect are respectively Two devices are prepared, and the apparatus detects the position by detecting two signals of phase A and phase B having a phase difference of 90 °.

  In the figure, the excitation loop pattern 4 on the first plane 1 is composed of two excitation loop patterns 4a and 4b similar to the excitation loop pattern 4 of the third mode shown in FIG. 6, with an interval of s2 above and below. The upper loop pattern 4a is connected in series as an A-phase excitation loop pattern, and the lower loop pattern 4b is connected in series as a B-phase excitation loop pattern 4b. The solid line pattern is formed and arranged on the front surface side of the substrate, and the dotted line pattern is formed and arranged on the back surface side. The excitation loop pattern 4 is connected to the excitation power source 7.

  The A-phase detection loop pattern 4a and the B-phase detection loop pattern 4b on the second plane 2 are the same two as the detection loop pattern 4 in FIG. 6, and are arranged with an interval of s2 above and below and excited. The loop patterns 4a and 4b are respectively shifted by 1 / 2P, and the start ends of the loop patterns 4a and 4b are connected to the nodes n3a and n4a and the nodes n3b and n4b.

  As for the resonance loop patterns 6a and 6b on the third plane 3, the A phase resonance loop pattern 6a and the B phase resonance loop pattern 6b similar to the resonance loop pattern 6 shown in FIG. The B-phase resonance loop pattern 6b is shifted by 1/4 P to the right with respect to the A-phase resonance loop pattern 6a, and the resonance capacitors C1a and C1b are connected to the B-phase resonance loop pattern 6b. Here, the interval s2 is preferably set to an interval at which the influence of the detected currents of the A-phase detection loop pattern and the B-phase detection loop pattern on each other can be ignored.

  The operation of this aspect is the same as that of the first aspect. Even if the excitation power source 7 is activated when there is no third plane 3 and only the first plane 1 and the second plane 2, the A phase detection loop is activated. No detection voltage is generated at the detection ends n3a and n4a and the detection ends n3b and n4b of the pattern 4a and the B-phase detection loop pattern 4b.

  Here, when the third plane 3 is arranged and the excitation power source 7 is activated, the operation is based on the operation principle of the first aspect of FIG. 1, and therefore, as shown in FIG. 11, the detection end n3a , N4a, a sine-wave A-phase detection voltage 71a that changes with a period P corresponding to the movement of the third plane 3, as shown by a solid line, is output to the detection ends n3b, n4b, and a B-phase resonance loop pattern 6b. Is shifted by ¼ P with respect to the A-phase resonance loop pattern 6a, so that a sinusoidal B-phase detection voltage 71b that changes with a period P advanced by ¼ P as shown by a dotted line appears. In this way, 90 ° phase difference A and B2 signals can be detected when the period P is set to an electrical angle of 360 ° corresponding to the movement of the third plane composed of a movable printed board or the like.

  If a sinusoidal loop pattern as shown in FIG. 4 is employed in the excitation loop pattern 4 and / or the detection loop pattern 5, the change in magnetic coupling with respect to the moving position can be made closer to a sine wave, so that a highly accurate sine Wave voltage detection can be realized. In addition, as a cordless linear position detection device, an inexpensive and highly accurate printed board type cordless linear position detection device that is resistant to external noise can be put to practical use. Other constituent elements are the same as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

[Sixth aspect]
FIG. 12 is a plan view showing a sixth aspect of the present invention. In this aspect, the excitation loop pattern 4 on the first plane 1, the detection loop pattern 5 on the second plane 2 of the fifth aspect, and The resonance loop pattern 6 on the third plane 3 is formed in a rectangular shape. Thus, if each loop pattern is constituted by a rectangular loop pattern, the excitation loop patterns 4a and 4b can be made into one excitation loop pattern 4, and the pitch P can be further reduced, so that the resolution is increased. Can do.

  Other components are the same as those in the fifth mode shown in FIG. 10, and the same components are denoted by the same reference numerals and description thereof is omitted.

[Seventh aspect]
Next, a seventh aspect of the present invention will be described. 13, 14 and 15 are plan views showing a seventh aspect of the present invention. 13 is a plan view showing the first and second planes 1 and 2, FIG. 14 is a plan view showing the third plane 3, and FIG. 15 is a schematic cross-sectional view showing a state in which these are combined. . In this aspect, an example applied to a rotational position detection device is shown. That is, the first plane, the second plane, and the third plane have a shape corresponding to the rotating body, for example, a disk shape, and these excitation coil, detection coil, and resonance coil are formed rotationally symmetrical with respect to the rotation center. is doing. By adopting such a configuration, the third plane can rotate freely with respect to the first plane and the second plane, and corresponds to the rotational movement of the third plane which is the movable portion. The rotation position is detected by detecting two signals of phase A and phase B having a phase difference of 90 ° in electrical angle.

  In FIG. 13, the first plane 1 is a circular plate-like body such as a multilayer printed board having an opening 11 at the center. On the first plane 1, an outer spiral coil loop 43a formed by folding the outer arcs r1 to r4 and an angle θ, and an inner space with an interval between the outer spiral coil loop 43a and the gap s2 are disposed. An excitation loop pattern 4 is formed which is composed of the arcs r5 to r8 and the inner spiral coil loop 43b formed by folding back at an angle θ. In this excitation loop pattern 4, the outer loop 43 a is an A-phase excitation loop, the inner loop 43 b is a B-phase excitation loop, connected in series, and further connected to an excitation power source 7.

  As shown in the figure, both the A-phase excitation loop 43a and the B-phase excitation loop 43b are composed of two loops having the same shape, and are arranged symmetrically with a pitch P (180 °), and the upper half loop is a right-handed ( When the exciting current i flows in the direction of the arrow, the upper half loop is marked with a cross as shown in the figure. The magnetic flux shown is generated vertically from the top to the bottom of the paper, and the lower half of the loop is formed so that the magnetic flux indicated by a mark is generated vertically from the bottom to the top of the paper.

  Similarly to the first plane 1, the second plane 2 is also a circular plate-like body such as a multilayer printed board having an opening 11 at the center. On the second plane 2, the detection loop pattern 5 has arcs r5 to r8 inward with a gap s2 between the outer spiral coil loop 53a formed by folding the outer arcs r1 to r4 and the angle θ. And an inner spiral coil loop 53b formed and arranged by folding back at an angle θ. The outer loop 53a is an A-phase detection loop, and the inner loop 53b is a B-phase detection loop, which are connected to the detection ends n3a and n4a and the detection ends n3b and n4b, respectively.

  As shown in the figure, each of the A-phase detection loop 53a and the B-phase detection loop 53b is composed of two loops having the same shape, and the excitation loop pattern 4 is right / left symmetrical just as it is rotated 1 / 2P (90 °) right. Arranged at a pitch P (180 °), the right half loop is formed in a series and connected so as to be clockwise (clockwise) and the left half loop is counterclockwise (counterclockwise).

  The third plane 3 shown in FIG. 14 is formed in a disc shape having an opening 11 so as to face the first plane 1 and the second plane 2 shown in FIG. It is formed and arranged so that it can freely rotate clockwise or counterclockwise around the center C.

  On the third plane 3, a resonance loop pattern 6 is formed by folding the outer spiral coil loop 63a formed by folding with the outer arcs r1 to r4 and the arcs r5 to r8 on the inner side with a gap s2. The inner spiral coil loop 63b is connected to the A-phase resonance capacitor C1a and the B-phase resonance capacitor C1b, respectively. The A-phase resonance loop which is the outer spiral coil loop 63a and the 63bB-phase resonance loop which is the inner spiral coil loop are each composed of two loops having the same shape, and are arranged in series so that the winding directions are different at a pitch P (180 °). Connected to each other and formed and arranged by being shifted by 1/4 P rotation from each other.

  Here, the interval of the gap s2 in these structures is preferably an interval at which the influence of the detection currents of the A-phase detection loop 53a and the B-phase detection loop 53b can be ignored. Further, the angle θ is provided to make a space such as an input / output line connection round, and it is desirable to make it as small as possible.

  Other constituent elements are the same as those of the first embodiment shown in FIG. 1, and the same constituent elements are denoted by the same reference numerals and description thereof is omitted.

  Next, the operation of this rotational position detection device will be described. If there is no third plane 3 and only the first plane 1 and the second plane are present, the A-phase detection loop 53a and the B-phase detection loop 53b are not shown in FIG. Therefore, no detection voltage is generated at the detection ends n3a and n4a and the detection ends n3b and n4b.

  Here, as shown in FIGS. 13, 14, and 15, when the third plane 3 is arranged at a distance from the first plane 1 and the second plane and the excitation power source 7 is activated, In the illustrated origin position og, the loop areas C31d and C32d of the A-phase resonance loop 63a are magnetically coupled to the loop areas C11d and C12d of the excitation loop 4 and the loop areas C21d and C22d of the A-phase detection loop 53a. Therefore, a resonance current flows through the A-phase resonance loop 63a, and as shown by the solid line in FIG. 16, the same positive-phase maximum detection voltage as that of the excitation power supply 7 is output as the A-phase detection voltage to the detection terminals n3a and n4a.

  Next, when the third plane 3 rotates around the center C axis at the same interval in the direction of the arrow, that is, clockwise in the direction of the paper, the basic operation similar to the first mode shown in FIG. Since the operation is based on the principle, a sinusoidal detection voltage having a period P shown by a solid line in FIG. 16 is output as the A-phase detection voltage 81a to the detection terminals n3a and n4a according to the rotation.

  At this time, since the B-phase resonance loop 63b is arranged to be rotated by 1/4 P counterclockwise with respect to the A-phase resonance loop 63a, the detection ends n3b and n4b are indicated by dotted lines in FIG. In addition, a sine wave B-phase detection voltage 81b that changes with a period P with a delay of 1/4 P is output to the right. In this way, 90 ° phase difference A and B2 signals can be detected and generated when the period P is an electrical angle of 360 ° corresponding to the rotational movement of the third plane 3.

  In addition, by changing the shape of the loop area of the A-phase resonance loop 63a and the B-phase resonance loop 63b, the change in magnetic coupling corresponding to the rotational position movement can be made closer to a sine wave. Detection is feasible.

  Furthermore, when the A-phase resonance loop 63a and the B-phase resonance loop 63b are configured in a loop pattern as shown in FIG. 17, a detection voltage with a larger amplitude can be obtained.

  In this way, it is possible to realize an inexpensive and highly accurate printed board type cordless rotational position detection device that is resistant to external noise.

  In this example, the detection voltage of the A signal and the B phase 2 signal of two periods is output with respect to the rotation of the mechanical angle of 360 °, but the loop area of the excitation loop and the detection loop is configured by 2n each. By doing so, it is possible to realize a cordless rotational position detection device that outputs a detection voltage of A and B phase 2 signals having a 2n period with respect to rotation of a mechanical angle of 360 °.

  In the 2n period rotational position detecting device, the excitation loop is composed of two loop areas, and the loop pattern composed of one loop area for each of the detection loop and the resonance loop is placed inside the B-phase loop and the C-phase. By additionally forming and arranging as a loop, it is possible to realize a rotation position detection device having a 2n period and capable of detecting one rotation signal.

  Further, also in this embodiment, the resonance capacitor of the resonance loop is short-circuited as described in the basic operation loop, or the same shape metal conductor plate is arranged at the pitch P instead of the resonance loop area. Therefore, various cordless rotational position detection devices can be realized according to the application.

[Eighth aspect]
Next, an eighth aspect of the present invention will be described. 18 and 19 are plan views showing an eighth aspect of the present invention. FIG. 18 is a plan view showing the first and second planes 1 and 2, and FIG. 19 is a plan view showing the third plane 3.

  In this example, an apparatus for detecting the position of the XY axes corresponding to the two-dimensional XY coordinate movement of the third plane 3 which is a movable part is shown. In other words, this is a device for detecting the position of the XY axes by converting the position of each axis into two signals of A phase and B phase having a phase difference of 90 ° in electrical angle.

  In FIG. 18, the X-axis A-phase excitation loop pattern 4a and the X-axis A-phase detection loop pattern 5a on the planes 1a and 2a are for detecting the X-phase A-phase signal. The X-axis A-phase excitation loop 4a is composed of a rectangular zigzag group having a pitch P as shown in the figure, and is an excitation loop composed of an outward path 41a and a return path 42a, as in the first mode, and from nodes n1a and n2a The excitation power source 7 is connected via an analog switch sw.

  As shown in the figure, the XA phase detection loop 5a is composed of an outward path 51a and a return path 52a as in the XA phase excitation loop 4a. The XA phase detection loop 5a is a rectangular zigzag group with a pitch P and is shifted by 1 / 2P with respect to the X excitation loop 4a. Arranged and connected to detection ends (nodes) n3a and n4a.

  The X-axis B-phase excitation loop pattern 4b and the X-axis B-phase detection loop pattern 5b on the planes 1b and 2b are for detecting the B-phase signal of the X-axis.

  The X-axis B-phase excitation loop 4b is composed of an outward path 41b and a return path 42b, and is arranged in a rectangular zigzag group with a pitch P and shifted by 1 / 4P with respect to the XA-phase excitation loop 4a. The excitation loop operates in the same manner, and is connected to the excitation power supply 7 from the nodes n1b and n2b via the analog switch sw.

  The X-axis B-phase detection loop 5b is composed of a forward path 51b and a return path 52b, and is a rectangular zigzag group with a pitch P, and is arranged with a 1 / 2P shift with respect to the XB-phase excitation loop 5a, and detection ends (nodes) n3b, n4b It is connected to the.

  The solid line pattern of the X-axis A-phase excitation loop 4a, the X-axis A-phase detection loop 5a, the X-axis B-phase excitation loop 4b, and the X-axis B-phase detection loop 5b represents the surface side of the substrate, and the dotted line pattern represents the back surface. Represents the side. These substrates can be formed of a printed circuit board or the like, and can be formed as a laminated substrate in the same manner as other embodiments. In this case, it is desirable to configure the planes 1a and 2a and the planes 1b and 2b as a multilayer substrate.

  The Y-axis A-phase excitation loop, Y-axis A-phase detection loop, Y-axis B-phase excitation loop, and Y-axis B-phase detection loop for detecting the Y-axis movement position rotate the X-axis loop 90 ° clockwise. It is only necessary to display the contacts for the Y axis on the analog switch SW, and the description thereof is omitted here.

  The third plane 3 is disposed so as to be parallel to the planes 1a, 2a, 1b, and 2b with a space therebetween so that it can move in parallel in all directions as indicated by arrows. The resonance loop pattern 6 is formed of a circular spiral coil pattern. The solid line pattern is formed and arranged on the back side of the substrate, and the dotted line pattern is formed and arranged on the surface side, and the resonance capacitor C1 is connected.

  If there is no third plane 3 and only the planes 1a, 2a, 1b, and 2b are present, the excitation power source 7 is activated and sw is activated, and the X-axis A-phase excitation loop 4a and the X-axis B-phase excitation loop are activated. Even if an exciting current flows through 4b, the same operation as in the first mode shown in FIG. 1 is performed, so that detection ends 3a and 4a and detection end 3b of X-axis A-phase detection loop 5a and X-axis B-phase detection loop 5b are detected. , 4b does not generate a detection voltage.

  When the resonance coil 6 of the third plane 3 exists at the position indicated by the broken line in FIG. 18, if the sw is activated and the excitation power source 7 is connected only to the X-axis A-phase excitation loop 4a, the first Therefore, the detection ends n3a and n4a are sine that changes at a period P corresponding to the movement of the X-axis of the third plane 3 as shown by the solid line in FIG. A wavy X-axis A-phase detection voltage is output. Next, when the excitation power source 7 is connected only to the X-axis B-phase excitation loop 4b by the operation of the analog switch sw, the X-axis B-phase excitation loop 4b and the X-axis B-phase detection loop 5b are respectively X-axis A-phase excitation. Since the loop 4a and the X-axis A-phase detection loop 5a are formed and arranged with a ¼ P shift, as shown by the dotted line in FIG. The shifted X-axis B-phase detection voltage is output to the detection terminals n3b and n4b.

  Here, the excitation power source 7 is operated so as to be alternately connected to the X-axis A-phase excitation loop 4a and the X-axis B-phase excitation loop 4b at a constant cycle, and after switching the connection, a predetermined time (preferably before switching) The AC X-axis A-phase detection voltage and the X-axis B-phase detection voltage output to the detection terminals n3a, n4a and the detection terminals n3b, n4b are synchronously rectified with the phase of the excitation power supply 7 after a period of time during which the resonance is attenuated. When the sampling hold is performed, as shown in FIG. 21, a DC sinusoidal X-axis A-phase detection voltage that changes at a period P corresponding to the movement of the X-axis of the third plane 3 and the X-axis as shown in FIG. The B phase detection voltage can be detected.

  Then, by performing the same detection process for the Y axis as for the X axis, a DC sine wave Y axis A phase detection voltage that changes at a period P corresponding to the movement of the Y axis of the third plane 3 and the Y axis A B-phase detection voltage (not shown) can be detected.

  In addition, the absolute position can be easily detected by a known method in this type of field because the excitation range of the excitation loop of each axis can be enlarged / reduced by an analog switch or the like in a cycle of 1 pitch 1P. .

  In this way, the position of each XY axis can be converted into A and B2 signals having a phase difference of 90 electrical degrees, so that the two-dimensional XY coordinates of the third plane 3 that is a movable part. It is possible to realize a coordinate position detection device that can detect a position cordlessly.

  The position detection device of the present invention can be suitably applied to a linear position detection device such as a linear encoder, and a rotation position detection device such as a rotary encoder or resolver. Further, it can be applied to a two-dimensional or multi-axis position detection device such as a digitizer.

It is a top view which shows the 1st aspect of the position detection apparatus of this invention. It is a schematic sectional drawing which shows the 1st aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 1st aspect of the position detection apparatus of this invention. It is a top view which shows the 2nd aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 2nd aspect of the position detection apparatus of this invention. It is a top view which shows the 3rd aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 3rd aspect of the position detection apparatus of this invention. It is a top view which shows the 4th aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 4th aspect of the position detection apparatus of this invention. It is a top view which shows the 5th aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 5th aspect of the position detection apparatus of this invention. It is a top view which shows the 6th aspect of the position detection apparatus of this invention. It is a top view which shows the 7th aspect of the position detection apparatus of this invention. It is a top view which shows the 7th aspect of the position detection apparatus of this invention. It is a schematic cross section which shows the 7th aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 7th aspect of the position detection apparatus of this invention. It is a top view which shows the structural example of the other 3rd plane in the 7th aspect of the position detection apparatus of this invention. It is a top view which shows the 8th aspect of the position detection apparatus of this invention. It is a top view which shows the 8th aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the detection voltage of the 8th aspect of the position detection apparatus of this invention. It is a wave form diagram which shows the state which carried out the synchronous rectification of the detection voltage of the 8th aspect of the position detection apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st plane 2 2nd plane 3 3rd plane 4 Excitation loop pattern 5 Detection loop pattern 6 Resonance loop pattern

Claims (9)

An exciting coil formed on the first plane so that forward winding and reverse winding appear alternately in at least one pitch unit in a fixed direction;
A detection coil formed on a second plane at a position shifted by a half pitch from the excitation coil, so that forward and reverse windings appear alternately in at least one pitch unit in the same direction as the excitation coil;
A resonance coil having a resonance capacitor connected in parallel to the third plane;
At least the excitation coil in the first plane and the detection coil in the second plane have magnetic coupling;
The third plane is spaced apart from the first plane and the second plane via a space, and is freely movable in a detection coil forming region serving as a detection region. The detection coil and the resonance coil can be magnetically coupled,
A position detection device that obtains a position detection voltage from the detection coil according to the position of the resonance coil.   2. The position detecting device according to claim 1, wherein the exciting coil on the first plane and the detecting coil on the second plane are formed so as to extend in one direction, and the third plane moves so as to slide in this forming region. .   The position detecting device according to claim 1, wherein the excitation coil on the first plane and the detection coil on the second plane are formed rotationally symmetrically, and the third plane moves so as to rotate in this formation region.   The position detection device according to claim 1, wherein the excitation coil and the detection coil are formed by two zigzag curves whose one ends are closed.   The position detection device according to claim 1, wherein the excitation coil and the detection coil are formed by connecting discontinuous spiral coils in series.   The position detection device according to claim 1, wherein a resonance capacitor portion of the resonance coil is short-circuited.   The position detection device according to claim 1, further comprising a metal conductor plate instead of the third plane resonance coil.   The position detection device according to claim 1, wherein the first plane and the second plane are configured by a laminated substrate.   The position detection device according to claim 1, wherein the position detection device has a plurality of detection axes for the first plane and the second plane and performs multi-axis position detection.

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