Contactless sensor device

Abstract

To provide a non-contact type sensor device capable of measuring an object to be measured inserted between a probe part and a conductor SOLUTION: A non-contact type sensor device having a measurement processing part for deriving a measurement value corresponding to a measured object by inserting the measured object into a gap where surfaces of a probe part and a conductive object face each other, wherein the probe part includes an electrode and a coil, and is capable of forming an electromagnetic field in the gap by being supplied with electricity, and the measurement processing part obtains correlation information that changes in correlation with a degree of thickness of the measured object inserted into the gap based on two types of detection values obtained from detection of the electromagnetic field, and performs thickness measurement.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a non-contact sensor device that enables measurement of an object to be measured. [Background technology]

[0002] Conventionally, there have been non-contact sensor devices that enable gap measurement by utilizing the electrostatic capacitance between a sensor surface (electrode) and a conductive target (workpiece) in order to measure minute gaps (spacing / distance).

[0003] As an example, Japanese Patent Application Laid-Open No. 2022-92813 (patent document) discloses a technology that enables a non-contact sensor device to measure the gap between a sensor surface and a conductive target. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-92813 Summary of the Invention [Problem to be solved by the invention]

[0005] Here, there is a strong demand for a non-contact sensor device that not only measures the gap as described above, but also accurately measures the thickness of an object to be measured when the object is inserted by creating an appropriate gap between the sensor surface and the conductive target.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide a non-contact sensor device that enables smooth thickness measurement of an object to be measured that is inserted into a predetermined gap created when the sensor surface is positioned relative to a conductive target, even when the positioning is performed by mechanical work using an industrial robot or the like that does not have high operating precision, or by manual work by an operator that may result in hand shake. [Means for solving the problem]

[0007] In order to achieve the above object, the non-contact sensor device of the present invention comprises: A sensor device having a probe unit, a detection unit, and a measurement processing unit, which performs non-contact thickness measurement of an object to be measured when the object to be measured is inserted into a gap where the probe unit and a given conductive object face each other, The aforementioned probe section is a housing having a predetermined surface facing a conductive object, an electrode disposed on the predetermined surface, and a coil disposed on the electrode and extending in a direction away from the conductive object; The predetermined surface is: a sensor surface having a common surface area that generates an electric field and a magnetic field in the gap based on electrical supply to the electrodes and the coil; The aforementioned measurement processing unit is The device is configured to be able to measure thickness by calculating correlation information based on a first detection value related to the magnetic field and a second detection value related to the electric field detected by the detection unit when the object to be measured is inserted into the gap, and a coefficient correlating with the thickness of the object to be measured.

[0008] Also, The aforementioned electrodes are the probe base material is provided by arranging on a predetermined surface of the probe part a probe substrate having: a first electrode capable of generating a first electric field in a central surface region of the sensor surface; a second electrode capable of generating a second electric field so as to surround the first electric field in a non-central surface region of the sensor surface; and insulating portions provided on the first electrode and the second electrode; The aforementioned insulating part is an insulating linear path that separates each of the first electrode and the second electrode into a plurality of segmented electrodes; a small electrode path for connecting a part of the segmented electrodes; Each of the first electrode and the second electrode is Based on the insulating linear paths and small electrode paths of the insulating part described above, an open loop pattern is formed to suppress the flow of induced currents that may occur in the central plane area and non-central plane area due to the magnetic field.

[0009] Also, The aforementioned probe substrate is The device is configured to include a second layer substrate that is laminated on the first layer substrate on which the first electrode and the second electrode that are patterned as described above are provided, The second layer board mentioned above is a first electrode for overlapping and covering an insulating portion disposed in a central surface region of the sensor surface; a second electrode for overlapping the insulating portion disposed in a non-central surface region of the sensor surface; is configured to be provided.

[0010] Also, The aforementioned probe substrate is The third layer substrate is disposed so as to overlap with the first layer substrate on which the first electrode related to the input side electricity supply and the second electrode related to the output side electricity supply are provided, The third layer board mentioned above is The first layer substrate is provided with a first electrode and a second electrode arranged to overlap and cover the first electrode and the second electrode, and the second electrode is configured to be provided with a second electrode related to the output side electricity supply. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a non-contact sensor device for measuring the thickness of an object to be measured that is inserted with a predetermined gap formed between the sensor surface and a conductive target. [Brief explanation of the drawings]

[0012] [Figure 1] 1A is a block diagram showing a schematic configuration of a non-contact sensor device according to the present embodiment, and FIG. 1B is a diagram showing a schematic sensor surface of a probe body of the present embodiment. [Figure 2]FIG. 2 is a diagram schematically showing the configuration of a second layer substrate according to the present embodiment. [Figure 3] FIG. 2 is a diagram schematically showing the configuration of a first layer substrate according to the present embodiment. [Figure 4] FIG. 10 is a diagram for explaining the relationship between the detection output and the gap. [Figure 5] FIG. 10 is a diagram illustrating a sensor surface according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The non-contact sensor device according to this embodiment will be described in detail below with reference to the drawings. Note that supplementary information in parentheses in this specification is an example of the present invention, and the present invention is not limited to the supplementary information. Furthermore, identical or equivalent elements are given the same reference numerals, and redundant explanations may be omitted.

[0014] Fig. 1(A) shows a block diagram of a schematic configuration of a non-contact type sensor device (hereinafter also referred to as a non-contact sensor device) 1 according to this embodiment. Fig. 1(B) shows a schematic sensor surface 14 of a housing of a probe body (probe section) 13 according to this embodiment, viewed vertically upward (+Z direction) from a vertically downward (-Z direction) position.

[0015] As shown in FIG. 1(A), the measuring means 2 in the non-contact sensor device 1 includes a capacitance type measuring means (AC constant current source circuit section) 7 and an eddy current type measuring means (high frequency signal oscillation circuit section) 12. The measurement means 2 according to this embodiment is configured as a main device including a predetermined measurement processing unit, a power supply unit, a detection unit, an execution unit, an input unit, a memory unit, a measurement processing unit (calculation unit), an A / D conversion unit, a voltage monitoring device unit (not shown), and the like.

[0016] The capacitance type measuring means 7 in the measuring means 2 is configured to have at least an AC constant current source 3, an impedance conversion circuit (voltage buffer circuit) 5 including an amplifier etc. 4, a second calculation unit 6, and a ground Gc for the capacitance type measuring means 7.

[0017] The eddy current measuring means 12 in the measuring means 2 is configured to have at least an oscillator circuit 8, a rectifier circuit 9, an amplifier circuit 10a, a first calculator 11, and a ground Ge for the eddy current measuring means 12.

[0018] In addition to the above, the capacitance type measuring means 7 and the eddy current type measuring means 12 include predetermined components such as resistor elements and capacitors, which are omitted from the illustration for convenience.

[0019] The probe body 13 electrically connected to the measuring means 2 shown in FIG. 1(A) is made of a cylindrical housing that holds one end of the cable section CV (CV1, CV2) for supplying electricity (applying a current or an electrical signal) from the measuring means 2 side and allows it to be moved around by an appropriate wire.

[0020] As shown in FIG. 1(B), the vertically downward surface (-Z direction side, predetermined surface) of the housing of the probe body 13 is configured to include a probe substrate (probe base material, flat plate electrode) 15 for a circular electrode, and a cover film (insulating layer, not shown, etc.) for covering and protecting the surface of the probe substrate 15.

[0021] The probe substrate 15 corresponds to a portion (a predetermined surface on the -Z direction side) that forms the sensor surface 14 that faces a grounded given conductive object (conductive target / conductive plate / metallic counter electrode) CD. The sensor surface 14 is formed based on a first layer substrate 16 that is provided with an electrode surface that is divided into two regions (a circular first electrode ELc and an annular second electrode ELg1).

[0022] As shown in FIG. 1(A), the probe substrate 15 has a stacked structure in which a first layer substrate 16, a second layer substrate 17 having approximately the same shape and size as the first layer substrate 16 so as to cover it, and a third layer substrate 60 having approximately the same shape and size as the second layer substrate 17 so as to cover it are stacked.

[0023] The sensor surface 14 of the first layer substrate 16 (-Z direction side) of the probe substrate 15 is configured as a surface made of an insulating material (such as a glass-epoxy substrate). Then, on this surface, copper foil or the like is provided to form an electrode surface divided into the two regions as a circular pattern 61. Furthermore, a cover film (such as an insulating layer not shown) is also provided to cover and protect the circular pattern 61.

[0024] 1(B), the annular pattern 61 provided on the first layer substrate 16 is configured so that a concentric and annular guard electrode surface (annular second electrode) ELg1 is formed so as to surround a circular central electrode surface (first electrode) ELc in the center. Note that the shape of the annular pattern 61 need only be annular, and may be polygonal instead of circular.

[0025] As shown in FIG. 1(A), the probe body 13 is configured to overlap the center electrode surface ELc so as to face the center electrode surface ELc, and to have a coil 18 extending in a direction away from the conductive material CD.

[0026] The measuring means 2 of this embodiment supplies electricity from a power supply unit (AC constant current source 3) to the annular pattern 61, thereby generating a first electric field E1 from the central electrode surface ELc in the central plane region of the sensor surface 14 and generating a second electric field E2 from the guard electrode surface ELg1 in the non-central plane region of the sensor surface 14.

[0027] 1(B), the annular pattern 61 is configured such that an annular third insulating wire 20 is disposed on the outer peripheral edge of the center electrode surface ELc, thereby electrically isolating the center electrode surface ELc from the guard electrode surface ELg1.

[0028] The sensor surface 14 of the probe body 13 is configured so that the inner section electrodes 22 (open loop patterns that suppress induced currents that occur when a magnetic field is generated) are formed by dividing a plurality of arc-shaped surfaces using copper foil or the like in the central circular region where the central electrode surface ELc is arranged.

[0029] In addition, in Figure 1(B), the open loop pattern formation that suppresses the flow of eddy currents (induced currents) Φ, consisting of a first insulated wire (first insulated linear path) 21 that electrically separates the inner section electrode 22 and a small electrode path (central through hole 23) that connects part of the inner section electrode 22 (section electrode), will be explained in detail later (Figure 3), so for convenience it is shown as an abbreviated diagram with dotted lines.

[0030] The sensor surface 14 of the probe body 13 is configured to be an outer section electrode 25 (an open loop pattern that suppresses induced currents that occur when a magnetic field is generated) that is formed into a plurality of arc-shaped surfaces using copper foil or the like in the annular region where the guard electrode surface ELg1 is arranged.

[0031] In addition, in Figure 1(B), the open loop pattern formation that suppresses the flow of eddy currents (induced currents) Φ, consisting of second insulated wires 24 (24a, 24b, 24c: second insulated linear paths) that electrically separate the outer section electrodes 25 (section electrodes, 25b, 25c) and small electrode paths (29, 28) that connect parts of the outer section electrodes 25, will be explained in detail later (Figure 3), and for convenience's sake, it is shown as an abbreviated diagram with dotted lines.

[0032] This allows electricity to be supplied to the coil 18 from the power supply unit (oscillator circuit 8) of the measuring means 2, thereby suppressing the induced current that would otherwise be generated in at least one of the electrodes 22 of the inner section and the electrodes 25 of the outer section due to the influence of magnetic field lines Φ that are generated to penetrate the inside of the coil 18 and pass through the sensor surface 14.

[0033] Figure 2 is a schematic illustration of the second layer substrate 17 constituting the probe substrate 15 of this embodiment, viewed from a vertically downward (-Z direction) position toward a vertically upward (+Z direction) position.

[0034] As shown in FIG. 1(A), the second layer substrate 17 has an opposing surface (-Z direction side) facing the upper surface of the first layer substrate 16, which is made of an insulating material (such as a polyimide film), a center electrode surface ELc is provided in the center of the opposing surface, and a guard electrode surface ELg2 is provided so as to surround the center electrode surface ELc.

[0035] As shown in FIG. 2, the second layer substrate 17 has a center electrode surface ELc provided as a linear inner electrode pattern 62 and a guard electrode surface ELg2 provided as a linear outer electrode pattern 63.

[0036] The inner electrode pattern 62 (center electrode surface ELc) in the second layer substrate 17 is arranged so as to overlap along the pattern formation of the first insulating wire 21 (or the first insulating wire 21 and the third insulating wire 20) provided in the first layer substrate 16 located on the lower side in Figure 1 (A), so as to form a linear open-loop pattern that can suppress the flow of eddy current (induced current) Φ.

[0037] Specifically, the shape of the inner electrode pattern 62 is linear so as to cover the first insulating wires 21 in a pattern extending radially from the center (central through-hole 23) of the first layer substrate 16 (sensor surface 14). Therefore, the inner electrode pattern 62 has substantially the same shape as the first insulating wires 21 (or the first insulating wires 21 and the third insulating wires 20) in a pattern extending radially, and is provided so as to become the linear inner electrode pattern 62 extending radially from the center of the second layer substrate 17.

[0038] The outer electrode pattern 63 (guard electrode surface ELg2) on the second layer substrate 17 is arranged so as to overlap along the pattern formation of the third insulating wire 20 and the second insulating wire 24 (or only the third insulating wire 20) provided on the first layer substrate 16 located below in Figure 1 (A), so as to form a linear open-loop pattern that can suppress the flow of eddy current (induced current) Φ.

[0039] Specifically, the shape of the outer electrode pattern 63 is linear so as to cover the third insulating wire 20, which is a circumferential line surrounding the electrode 22 in the inner section of the first layer substrate 16 (sensor surface 14), and the second insulating wire 24, which is a pattern extending radially from the electrode 25 in the outer section of the first layer substrate 16. Therefore, the outer electrode pattern 63 has approximately the same shape according to the pattern formation of the third insulating wire 20 and the second insulating wire 24 (or only the third insulating wire 20), and is provided as a linear outer electrode pattern 63 extending in the outer periphery surrounding the inner electrode pattern 62 of the second layer substrate 17.

[0040] In addition, a fourth insulating wire 62 is provided in a ring shape on the opposing surface of the second layer substrate 17 that faces the upper surface of the first layer substrate 16 to electrically isolate the inner electrode pattern 62 and the outer electrode pattern 63.

[0041] Based on the electrical supply from the power supply unit (AC constant current source 3) of the measuring means 2, a first electric field (not shown) is generated from the inner electrode pattern 62 (center electrode surface ELc) of the second layer substrate 17 toward the sensor surface 14, and a second electric field (not shown) is generated from the outer electrode pattern 63 (guard electrode surface ELg2) toward the sensor surface 14.

[0042] As shown in FIG. 1(A), the third layer substrate 60 has an opposing surface (-Z direction side) facing the upper surface of the second layer substrate 17 made of an insulating material (such as a polyimide film), and is configured to have a guard electrode surface (second electrode) ELg3 that covers and overlaps the second layer substrate 17 and the first layer substrate 16 (sensor surface 14) over the entire area.

[0043] Based on the electrical supply from the power supply unit (AC constant current source 3) of the measuring means 2, a second electric field (not shown) can be generated from the guard electrode surface ELg3 toward the sensor surface 14 (first layer substrate 16 and second layer substrate 17).

[0044] In the probe substrate 15 shown in FIG. 1(A), the center electrode surface ELc of the first layer substrate 16, the center electrode surface ELc of the second layer substrate 17, and the guard electrode surfaces ELg1 to ELg3 are provided so as to be integrally formed while maintaining an insulating relationship with each other.

[0045] As a first variant example of the second layer substrate 17 described above on which the third layer substrate 60 as shown in FIG. 1(A) is laminated, only a center electrode surface ELc (without a guard electrode surface ELg2) may be provided on the opposing surface of the second layer substrate 17 facing the upper surface of the first layer substrate 16, and the center electrode surface ELc may be provided as a predetermined open loop pattern (for suppressing the flow of eddy currents) having at least an inner electrode pattern 62, or as a predetermined open loop pattern including the inner electrode pattern 62 and the outer electrode pattern 63, so that the open loop pattern can overlap at least the first insulating wire 21 (or the second insulating wire 24, or the third insulating wire 20) provided on the first layer substrate 16 located on the lower side in FIG. 1(A).

[0046] Furthermore, as a second variant example of the second layer substrate 17 described above, only a guard electrode surface ELg2 (without a center electrode surface ELc) may be provided on the opposing surface of the second layer substrate 17 that faces the upper surface of the first layer substrate 16, and the guard electrode surface ELg2 may be provided as a predetermined open loop pattern (for suppressing the flow of eddy currents) having at least an outer electrode pattern 63, or as a predetermined open loop pattern including an inner electrode pattern 62 and an outer electrode pattern 63, and the open loop pattern may be configured to overlap at least the second insulating wire 24 (or the first insulating wire 21, the third insulating wire 20) provided on the first layer substrate 16 located on the lower side in Figure 1(A).

[0047] Furthermore, the vertically upper side (inside the housing of the probe body 13) of the third layer substrate 60 of the probe board 15 is provided so as to enable the extraction of a plurality of wires (CV1, CV2) that are components of the cable section CV. These wires (CV1, CV2) enable electrical board connection or coil connection for connecting the measuring means 2 and the probe body 13 as a wired connection.

[0048] In addition, in the connection of the impedance conversion circuit 5 that can supply electricity from the power supply unit of the measuring means 2 to the annular pattern 61, the flow of electricity is such that the center electrode surface ELc (first electrode) on the input side related to the electricity supply is connected to the guard electrode surfaces ELg1 to ELg3 (second electrodes) on the output side related to the electricity supply.

[0049] Therefore, by using the multiple wires that make up the cable CV1 shown in Figure 1(A) to flow a constant current I (also referred to as AC constant current, hereinafter simply referred to as current) from the power supply unit of the measuring means 2 to the probe substrate 15, electricity can be supplied to the center electrode surface ELc provided on the second layer substrate 17 and the input (first electrode) side that leads to the center electrode surface ELc provided on the first layer substrate 16 via an electrical path (small electrode path, through hole) not shown.

[0050] Next, electricity can be supplied to the guard electrode surface ELg1 provided on the first layer substrate 16 and the guard electrode surface ELg1 / guard electrode surface ELg2 provided on the second layer substrate 17 via electrical paths (small electrode paths, through holes) not shown, and electricity can also be supplied from the output (second electrode) side to the guard electrode surface ELg3 provided on the third layer substrate 60.

[0051] The impedance conversion circuit 5 controls the output voltage V out The input voltage V inThis has the function of lowering the output impedance relative to the input impedance while making the potential of the guard electrode surfaces ELg1 to ELg3 equal to the potential of the center electrode surface ELc, thereby enabling the guard electrode surfaces ELg1 to ELg3 to assist in sensing based on the center electrode surface ELc.

[0052] As a modified example, instead of a stack consisting of first layer substrate 16, second layer substrate 17, and third layer substrate 60, at least one of second layer substrate 17 or third layer substrate 60 may be stacked on first layer substrate 16.

[0053] The second calculation unit 6 in the capacitance type measurement means 7 has a measurement function that can calculate a second output value Vc based on the detection value Vm, which is a detection corresponding to the capacitance Cx related to the gap g (g1, g2), as an investigation into changes in the state of a given distance (hereinafter also referred to as gap g / parallel electric field / predetermined electromagnetic field / measurement range) between the conductive object CD shown in Figure 1 (A) and the sensor surface 14 (measurement to obtain a second detection value (second voltage information) obtained from detection related to at least one of the voltage, current, frequency, and phase when an electric field is generated from an applied flat electrode).

[0054] The first electric field E1 generated from the central electrode surface ELc shown in Figure 1(A) is used as the detection target for calculating the second output value Vc, which is obtained based on the detection of the capacitance Cx in the first electric field E1 (obtaining the voltage component applied to the parallel electric field in the central part of the ring).

[0055] The guard electrode surfaces ELg1, ELg2, and ELg3 shown in FIG. 1(A) are configured to generate a composite guard electric field that is surrounded by a ring-shaped second electric field E2 that is generated around the outside of the center electrode surface ELc and a second electric field (not shown) that is generated above and covering the first electric field E2, in order to assist in detecting the capacitance Cx of the first electric field E1 generated from the center electrode surface ELc associated with the sensor surface 14.

[0056] When an electric field is generated by the composite guard, the electric field lines U that may be disturbed at the end (the outer electrode 25) of the finite-sized annular pattern 61 facing the grounded conductive object CD are generated with respect to the second electric field E2 generated from the guard electrode surfaces ELg1 and ELg2. In other words, the second electric field E2 is no longer a parallel electric field.

[0057] From this, in the first electric field E1 generated directly below the center electrode surface ELc, parallel electric field lines are maintained, resulting in a parallel electric field, and since the reciprocal of the capacitance Cx here is proportional to the gap g (g1, g2), sensing assistance can be achieved that enables the second output value Vc to be calculated accurately based on the capacitance Cx.

[0058] In addition, the second output value Vc in this embodiment is calculated based on detection related to the state change of the capacitance Cx in the gap g (g1, g2) shown in Figure 1 (A) and correlation information (coefficient or group of coefficients) obtained based on this detection, so it has the property of being a value that is affected (or is easily affected) when the insulating plate T, which is the object to be measured, is inserted.

[0059] Furthermore, the second output value Vc according to this embodiment has the property of being less susceptible to the influence of the conductivity of the conductive material CD.

[0060] 1(A), inside the cylindrical interior of the housing of the probe body 13, the coil 18 (opening surface of the coil) is arranged to face and overlap vertically above (on the +Z direction side) the center electrode surface ELc of the annular pattern 61 that faces the conductive material CD. Also, the guard electrode surface ELg1, which is concentric and annular and surrounds the center electrode surface ELc in the center, is arranged vertically above the guard electrode surface ELg1 so as not to overlap the coil 18.

[0061] Then, by filling the cylindrical interior of the housing that constitutes the probe body 13 with a filler (such as epoxy resin) not shown, it becomes possible to hold items placed inside the cylindrical interior of the housing (forming a housing).

[0062] This makes it possible to reduce the size of the probe body 13. That is, it becomes possible to obtain calculation information (second output value Vc, first output value Ve) for contactlessly measuring the thickness of the object to be measured from detection related to the first electric field E1 (electrostatic capacitance) that can be generated from the center of the sensor surface 14 toward the conductive object CD and the magnetic field Φ (eddy current) described later, and correlation information (coefficient or group of coefficients) obtained based on this detection.

[0063] The physical sizes of the probe substrate 15, the center electrode surface ELc, and the coil 18 may be designed appropriately according to the measurement range (gap g1) required for the desired probe.

[0064] Furthermore, the coil 18 according to this embodiment is connected in parallel with a capacitor (not shown), and this parallel connection forms a resonant circuit 19. Furthermore, this resonant circuit 19 is electrically connected to the oscillator circuit 8 (see FIG. 1(A)) via a capacitor (not shown).

[0065] The coil 18 according to this embodiment is a sensor coil formed by winding an appropriate number of turns of insulating copper wire. This insulating copper wire may be wound around a ferromagnetic or non-magnetic bobbin, or may be wound without a bobbin.

[0066] Then, when the high-frequency signal generated by the oscillator circuit 8 shown in Figure 1(A) is supplied to the resonant circuit 19, a magnetic field (hereinafter also referred to as a high-frequency magnetic field, a magnetic field, or a magnetic flux) Φ is generated from the coil 18 toward the conductive material CD across the gap g1.

[0067] 1(A), the magnetic flux associated with the magnetic field Φ in this embodiment is generated so as to pass through the central circular region on the sensor surface 14 and head toward the conductive object CD. As a result, within the measurement range (within the magnetic field Φ) where the magnetic field Φ generated from the coil 18 also passes through the conductive object CD, an eddy-shaped induced current (hereinafter referred to as an eddy current) ec is generated within the conductive object CD.

[0068] The first calculation unit 11 in the eddy current measuring means 12 has a measurement function that can calculate a first output value Ve based on the coil impedance (voltage component related to eddy current, output voltage Vα) that is detected according to the eddy current ec in the gap g1, as an investigation into changes in the state of the gap g1 between the conductive material CD and the sensor surface 14 shown in Figure 1(A) (measurement to obtain a first detection value (first voltage information) obtained from detection related to at least one of the voltage, current, frequency, and phase when a magnetic field Φ is generated from an applied coil), based on the fact that eddy current ec is generated within the conductive material CD.

[0069] The first output value Ve in this embodiment is calculated based on a detection related to the state change due to eddy current in the gap g1 shown in Figure 1 (A) and correlation information (coefficients) obtained based on this detection, and therefore has the property of being a value that is not affected (or is less affected) when the dielectric plate (hereinafter referred to as insulating plate) T, which is the object to be measured, is inserted into the gap g1.

[0070] Furthermore, the first output value Ve according to this embodiment has a property that it is easily affected by the conductivity of the conductive material CD. For example, when the conductive material CD is Fe, Cu, Al, or the like, the sensitivity thereof changes.

[0071] As described above, when the insulating plate T, which is the object to be measured, is inserted into the gap g1 in which a predetermined electromagnetic field can be formed by supplying electricity to the probe body 13, the measuring means 2 of this embodiment is capable of performing measurement processing that enables detection of changes in the electrical state (electric field) that are affected by this insertion or changes in the electrical state (magnetic field) that are not affected by this insertion, and is capable of simultaneously calculating the second output value Vc and the first output value Ve, whose electrical detection components differ (correlate).

[0072] The magnetic field lines Φ generated from the coil 18 shown in FIG. 1(A) pass mainly through the central circular region (center electrode surface ELc) of the sensor surface 14 and do not pass through the annular pattern 61 (donut-shaped flat electrode, guard electrode surface ELg1), thereby improving the quality of the magnetic field Φ generated in the gap g1.

[0073] This enables sensing assistance that can accurately detect the first output value Ve based on the detection of a disturbance-free magnetic field Φ. It also makes it possible to lengthen the gap g1 (measurement range, distance between opposing surfaces) that can induce an eddy current ec in the conductive object CD.

[0074] In addition, the measurement means 2 of this embodiment is configured as a main device that further includes an input means, a memory means, a measurement processing means (calculation means), an A / D conversion means, etc., which are omitted from the illustration for convenience.

[0075] Specifically, the input means (not shown) in the measurement means 2 according to this embodiment has an input function for a second detection value Vc corresponding to the detection (electric field) related to the gap g (g1, g2) from measurement by the capacitance type measurement means 7, and a first output value Ve corresponding to the detection (magnetic field) related to the gap g1 from measurement by the eddy current type measurement means 12, and the second detection value Vc and the first output value Ve are used for control of measurement processing etc. (first processing or second processing).

[0076] Furthermore, the memory means (not shown) in the measuring means 2 according to this embodiment is provided with a processing function for memory processing or memory settings (such as a memory table) related to information on values ​​related to the detection of the above-mentioned various (voltage components), information in the first coefficient section (group of proportional constants) that enables processing using one first coefficient or multiple groups of first coefficients that have previously determined the correlation between the gap g1 and the detection value related to the magnetic field, and information in the second coefficient section (group of correlation variables) that enables processing using one second coefficient or multiple groups of second coefficients that have previously determined the correlation between the gap g2 and the detection value related to the electric field.

[0077] In addition, the proportionality constant (or correlation variable) in the present invention is considered to include stored information (coefficient information) calculated based on any one of vacuum, dielectric constant, relative dielectric constant, vacuum dielectric constant, relative magnetic permeability, and conductivity, or a combination of these.

[0078] In addition, the proportionality constant (or correlation variable) in the present invention is also used in the measurement process by storing and setting it as memory information (coefficient information) for calculation through pre-specifying (calibrating) sampling to obtain the preliminary second output value Vc and the preliminary first output value Ve from detection (acquisition of voltage components) related to the electromagnetic field in the gap g formed by preparing a known conductive object and inserting a measured object (dielectric) with a known thickness.

[0079] Furthermore, the measurement processing means (not shown) in the measurement means 2 according to this embodiment has a processing function that determines a second output value Vc relating to the capacitance output or a first output value Ve relating to the eddy current output based on measurement processing that enables predetermined calculations to be performed using the above-mentioned detection value and a predetermined set of proportional constants (coefficients in the first coefficient section) or a set of correlation variables (coefficients in the second coefficient section), and that enables the execution of the difference processing described below using this second detection value Vc and the first output value Ve.

[0080] In addition, the A / D conversion means (not shown) in the measurement means 2 of this embodiment has a processing function that converts analog data (measurement value) corresponding to the difference value (correlation information) obtained by the difference processing described below into digital data corresponding to the thickness of the insulating plate T, digitizes it, and enables measurement display corresponding to the digitization to be executed on a predetermined display screen (voltage monitor device section).

[0081] [Configuration of sensor surface 14] FIG. 3 is a schematic diagram of the first layer substrate 16, showing the sensor surface 14 based on the center electrode surface ELc and the guard electrode surface ELg1 that face the conductive material CD.

[0082] As shown in FIG. 3, in the central surface region (electrode 22 of the inner section) of the sensor surface 14 provided on the first layer substrate 16, a circular central electrode surface ELc, a central through hole 23, and a first insulating wire (first insulating portion) 21 are provided.

[0083] The central through hole 23 shown in Figure 3 is provided to penetrate and connect the central electrode surface ELc of the first layer substrate 16 to the central electrode surface ELc provided on the second layer substrate 17 so as to overlap it, thereby enabling electrical conduction.

[0084] In addition, the first insulating wires 21 shown in Figure 3 are arranged in multiple pieces (eight slits) extending radially from the edge of the land (the center of the sensor surface 14, the small electrode path connecting parts of the inner sections) related to the central through hole 23.

[0085] Then, a plurality of first insulating wires 21 extending radially divide the circular central electrode surface ELc provided on the first layer substrate 16 into a plurality (eight) of fan-shaped regions, which are electrically separated to form inner section electrodes 22 (metal surfaces made of metal such as copper foil, a plurality of section electrodes) in the central surface region of the sensor surface 14.

[0086] In addition, the electrodes 22 of all (eight) divided inner sections are electrically connected at points (connections that connect parts of the inner sections together at points) at the central corners (vertices) based on each fan-shaped area and the lands associated with the central through-hole 23.

[0087] Therefore, the current I that flows through the central through-hole 23 due to the electricity supplied from the measuring means 2 flows to each of the electrodes 22 (central electrode surface ELc, multiple sector-shaped areas) of the inner section provided on the first layer substrate 16.

[0088] In this embodiment, as an eddy current e is generated in the conductive material CD from the electrically supplied coil 18, an eddy current e can also be generated on the central electrode surface ELc of the first layer substrate 16. For this reason, the central electrode surface ELc is divided into a plurality of sector-shaped regions by the first insulating wires 21, so that the generation of eddy current e is limited to a small scale, and the electrodes 22 of the inner sections are configured as an open-loop pattern that suppresses (inhibits) electrical loops.

[0089] 3, all of the first insulating wires 21 provided on the center electrode surface ELc of the first layer substrate 16 are configured to be covered from above and below by an inner electrode pattern 62 (center electrode surface ELc) provided on the second layer substrate 17 that overlaps the first layer substrate 16. The inner electrode pattern 62 is configured as a linear pattern that follows the shapes of each of the multiple first insulating wires 21 extending radially from the first layer substrate 16 (see FIG. 2).

[0090] As a result, the inner section electrode 22 (center electrode surface ELc) provided on the first layer substrate 16 and the inner electrode pattern 62 (center electrode surface ELc) provided on the second layer substrate 17 are in an overlapping (double guard) relationship, and behave as if they were a single center electrode surface ELc, generating a seamless first electric field E1.

[0091] As another pattern shape of the center electrode surface ELc provided on the second layer substrate 17, a plurality of insulating wires (not shown) extending radially may be provided to divide the center electrode surface ELc into smaller portions so as to be out of phase with and not overlap the radially extending first insulating wires 21. That is, a modified embodiment may be adopted in which the first layer substrate 16 can cover the radially extending first insulating wires 21, while the inner electrode pattern (center electrode surface ELc) divided into smaller portions by the insulating wires (not shown) provided on the second layer substrate 17 is laminated on top.

[0092] As shown in FIG. 3, in the annular outer peripheral region (electrode 25 of the outer section) surrounding the central surface region (electrode 22 of the inner section) of the sensor surface 14, a guard electrode surface ELg1 is arranged with a third insulating wire (insulating portion) 20 interposed therebetween to electrically isolate it from the center electrode surface ELc, a second insulating wire (second insulating portion) 24a, and a through hole (not shown).

[0093] In addition, a through hole (not shown) is provided to penetrate and connect the guard electrode surface ELg1 of the first layer substrate 16 to the guard electrode surface ELg2 provided on the second layer substrate 17 so as to overlap it, thereby enabling electrical conduction.

[0094] The second insulating wire 24a shown in FIG. 3 is provided with a plurality of wires (eight slits) extending radially from the center of the sensor surface 14.

[0095] Then, a plurality of radially extending second insulating wires 24a divide the guard electrode surface ELg1 provided around the outer periphery of the first layer substrate 16 into a plurality (eight) arch-shaped regions to form electrically isolated outer section electrodes 25 (metal surface made of metal such as copper foil, a plurality of section electrodes).

[0096] Furthermore, the outer section electrode 25 (guard electrode surface ELg1) provided on the first layer substrate 16 is electrically divided into the left and right sides in Fig. 3 by the second insulating wire 24b and the second insulating wire (second insulating portion having a linear positional relationship) 24c. That is, the guard electrode surface ELg1 is divided into a group (four) of first outer section surfaces 25b that are electrically connectable only on the left side in Fig. 3, and a group (four) of second outer section surfaces 25c that are electrically connectable only on the right side in Fig. 3.

[0097] 3, each of the four adjacent first external segment surfaces 25b (in each group) is provided with an outer peripheral electrode surface (small electrode path) 28 or an inner peripheral electrode surface (small electrode path) 29 for electrical connection between the first external segment surfaces 25b. Similarly, each of the four adjacent second external segment surfaces 25c (in each group) is provided with an outer peripheral electrode surface (small electrode path) 28 or an inner peripheral electrode surface (small electrode path) 29 for electrical connection between the second external segment surfaces 25c.

[0098] The outer peripheral electrode surface 28 is provided as a small electrode path that electrically connects a point near the outer periphery to one of the second insulating wires 24a. The inner peripheral electrode surface 29 is provided as a small electrode path that electrically connects a point near the inner periphery to one of the second insulating wires 24a. The outer peripheral electrode surfaces 28 and the inner peripheral electrode surfaces 29 are arranged in an alternating order on each of the radially extending second insulating wires 24a to form an electrical bridge (point connection), allowing current I to flow separately to either the first outer segment surface 25b or the second outer segment surface 25c.

[0099] In this embodiment, when an eddy current e is generated in the conductive material CD from the electrically supplied coil 18, there is a possibility that an eddy current e may also be generated in the guard electrode surface ELg1 of the first layer substrate 16. For this reason, the guard electrode surface ELg1 is divided into a plurality of arch-shaped regions by the second insulating wire 24a, so that the generation of eddy current e is limited to a small scale, and the outer section electrode 25 is configured as an open-loop pattern that suppresses (inhibits) electrical loops.

[0100] In addition, all of the second insulating wires 24a provided on the guard electrode surface ELg1 of the first layer substrate 16 shown in Figure 3 are configured to be covered from above and below by the outer electrode pattern 63 (guard electrode surface ELg2) provided on the second layer substrate 17 that overlaps the first layer substrate 16.

[0101] From this, the outer section electrode 25 (guard electrode surface ELg1) provided on the first layer substrate 16 and the outer electrode pattern 63 (guard electrode surface ELg2) provided on the second layer substrate 17 are in an overlapping (double guard) relationship, and behave as if they were a single guard electrode surface ELg, so that the second electric field E2 is generated seamlessly.

[0102] As another pattern shape of the guard electrode surface ELg2 provided on the second layer substrate 17, a plurality of insulating wires (not shown) extending radially may be provided to divide the second insulating wires 24a into smaller portions so as to be out of phase with and not overlap with the radially extending second insulating wires 24a. That is, a modified embodiment may be adopted in which the outer electrode pattern (guard electrode surface ELg2) divided into smaller portions by the insulating wires (not shown) provided on the second layer substrate 17 is laminated on top while the first layer substrate 16 is able to cover the radially extending second insulating wires 24a.

[0103] The smaller the electrode area of ​​each of the inner section electrode 22 and the outer section electrode 25 is divided, the smaller the eddy current ec is suppressed. Therefore, it is preferable to increase the number of divisions by increasing the number (8) of the radially extending first insulated wires 21 or second insulated wires 24a.

[0104] However, the first insulating wire 21 or the second insulating wire 24a may be divided into a predetermined number of wires, including one, or each of the inner section electrode 22 and the outer section electrode 25 may be formed into an appropriate open loop pattern shape using insulating curves (insulated linear paths).

[0105] Also, a modified embodiment may be adopted in which at least one of the center electrode surface ELc and the guard electrode surface ELg is made into a segmented electrode having an open loop pattern.

[0106] Furthermore, the probe substrate 15 according to this embodiment may be configured as a sheet substrate of a thin film resistor formed by vapor deposition of a nichrome alloy, for example. That is, the gap g may be formed by passing the magnetic field Φ generated by the coil 18 through the probe substrate 15 made of a sheet substrate.

[0107] Therefore, the sensor surface 14 shown in Fig. 3 is an example of an open loop pattern. As long as the pattern is formed to suppress (inhibit, limit) the electrical loop, various patterns such as a radial, comb, spiral, circular, or snake-like pattern may be used. In addition, the thickness of the insulating portion (insulating wire) shown in the figure may be set appropriately.

[0108] Furthermore, the shape of the probe substrate 15 or the central electrode surface ELc is not limited to a disk shape, but may be a predetermined shape such as a semicircular, curved, wavy, rectangular, or triangular (polygonal) shape.

[0109] [Configuration of Modified Example of Sensor Surface 14] FIG. 5 shows a modification of the first layer substrate 16, in which the central electrode surface (first electrode) ELc and the guard electrode surface (second electrode) EL g 1 is a schematic diagram showing a modified example of the sensor surface 14 formed based on the sensor surface 14 of the sensor 1 of the present invention. In the following description, the same or equivalent elements as those described above will be assigned the same reference numerals.

[0110] As shown in Figure 5, in the central surface area of ​​the sensor surface 14 provided on the first layer substrate 16 of the modified example, a circular guard electrode surface ELg1, a central through hole 23 that enables electrical conduction based on the electrical supply from the measuring means 2, and a first insulating wire (first insulating portion) 21 are provided.

[0111] The first insulating wires 21 in FIG. 5 are provided in multiple lines (eight slits) extending radially from the edge of the land (the center of the sensor surface 14, the small electrode path) associated with the central through-hole 23.

[0112] The guard electrode surface ELg1 provided on the first layer substrate 16 according to the modified example is divided into a plurality (eight) of sector-shaped areas by a plurality of radially extending first insulating wires 21, and electrically separated divided electrodes (metal surfaces made of metal such as copper foil, a plurality of segmented electrodes) are formed.

[0113] All (eight) divided guard electrode surfaces ELg1 are formed so that the central corners (vertices) of each fan-shaped region and the lands associated with the central through-holes 23 are electrically connected at points (connections are formed by connecting parts together at points).

[0114] Therefore, in the central surface area of ​​the sensor surface 14 provided on the first layer substrate 16 in the modified example, the current I that flows through the central through-hole 23 due to the electrical supply from the measuring means 2 flows to each of the guard electrode surfaces ELg1 that are divided into multiple sector-shaped areas.

[0115] In this embodiment, the coil 18 is arranged so as to overlap with the guard electrode surface ELg1 within the housing of the probe body (probe section) 13, and as an eddy current ec is generated in the conductive material CD from the coil 18 supplied with electricity, it is possible to generate eddy currents ec in a plurality of divided sector-shaped areas (guard electrode surface ELg1), but the generation of eddy currents ec is limited to a small scale, and an open-loop pattern is configured to suppress (inhibit) electrical loops.

[0116] 5, the center electrode surface ELc provided on the first layer substrate 16 according to the modified example is formed as a donut-shaped center electrode surface ELc. A guard electrode surface ELg1 is disposed in the hollow portion (central circular region) in the center of the donut-shaped center electrode surface ELc. A concentric, annular guard electrode surface ELg2 is disposed so as to surround the outer periphery of the donut-shaped center electrode surface ELc.

[0117] Therefore, when electricity is supplied from the measurement means 2 to the first layer substrate 16 according to the modified example, a circular first electric field E1 is generated from the donut-shaped center electrode surface ELc. Furthermore, when electricity is supplied to the guard electrode surface ELg1, a second electric field E2 is generated in the hollow portion of the donut-shaped center electrode surface ELc, and when electricity is supplied to the guard electrode surface ELg2, a second electric field E2 is generated on the outer periphery of the donut-shaped center electrode surface ELc. In other words, the second electric fields E2 can be generated so as to sandwich the first electric field E1 from the inside and outside.

[0118] 5, the inner and outer insulating circumferential wires 26 and 27 are arranged concentrically at both the inner and outer peripheral edges of the donut-shaped center electrode surface ELc. This allows the donut-shaped center electrode surface ELc to be electrically isolated from the inner and outer guard electrode surfaces ELg1 and ELg2. The shapes of the center electrode surface ELc, guard electrode surfaces ELg1, and guard electrode surfaces ELg2 do not have to be circular, and may be polygonal.

[0119] As a variant, depending on the arrangement of the coil 18, the area where the center electrode surface ELc is arranged may be a smooth electrode surface (not divided into multiple arc-shaped surfaces) that does not have an open loop pattern having the first insulating wire 21.

[0120] [Configuration of the capacitance type measuring means 7] The AC constant current source 3 of the measuring means 2 of this embodiment generates a current based on the generation of a reference AC voltage having a predetermined angular frequency ω and a predetermined amplitude, and enables the current to flow to the wiring (the inner conductor or outer conductor of the cable CV1) electrically connected to the probe substrate 15.

[0121] The probe substrate 15, which receives the above current through the cable CV1 (wiring), is the part that constitutes the sensor surface 14 that faces the conductive material CD, and enables the second electric field E2 to be generated from the annular pattern 61.

[0122] The annular pattern 61 can also form a central electrode surface ELc and an outer guard electrode surface ELg1 that surrounds and is electrically isolated from the central electrode surface ELc by the third insulating wire.

[0123] The center electrode surface ELc shown in FIG. 1(A) is connected to the inner conductor (wiring) of the coaxial cable CV1, which is made of a shield braid. The guard electrode surfaces ELg1, ELg2, and ELg3 are connected to the outer conductor (wiring) of the cable CV1, which is insulated from the inner conductor. This allows the impedance conversion circuit 5 to function as a driven shield. As a result, the effect of the capacitance between the inner and outer conductors in the cable CV1 can be canceled.

[0124] 1(A) are configured to extend independently and in parallel so as not to be electrically affected by each other, allowing for routing and movement by the probe body 13. However, the cables (CV1, CV2) may be configured as an integrated cable section that is bundled together so as to be independent and in parallel so as not to be electrically affected by each other.

[0125] Furthermore, the impedance conversion circuit 5 associated with the measuring means 2 of this embodiment is configured to function as a voltage follower because it includes the amplifier 4 and the like.

[0126] As shown in Figure 1(A), the input (input voltage V in ) is connected to the center electrode surface ELc of the probe substrate 15. out ) is connected to guard electrode surfaces ELg1, ELg2, and ELg3 of the probe board 15.

[0127] Based on the above connection configuration, the center electrode surface ELc and the guard electrode surfaces ELg1 to ELg3 shown in FIG. 1(A) can be set to the same AC potential, and the center electrode surface ELc and the guard electrode surfaces ELg1 to ELg3 can behave as if they were a single electrode.

[0128] This makes it possible to prevent current from flowing from the center electrode surface ELc to the guard electrode surfaces ELg1 to 3. Furthermore, it becomes possible to cancel the influence of the stray capacitance C0 between the center electrode surface ELc and the guard electrode surfaces ELg1 to 3.

[0129] Therefore, the sensor surface 14 according to this embodiment is provided with the guard electrode surfaces ELg1 to ELg3, and thus can suppress disturbance of the electric field E (electric lines of force) generated at the center electrode surface ELc.

[0130] Furthermore, the influence of the capacitance existing between the predetermined wiring (internal conductor) associated with the center electrode surface ELc and the non-predetermined wiring (external conductor) associated with the guard electrode surfaces ELg1 to ELg3 can also be cancelled.

[0131] Therefore, the disturbance of the electric field lines at the end of the probe substrate 15 of finite size facing the conductive material CD occurs only in the outer periphery related to the second electric field E2 (guard electrode surfaces ELg1-2), and an ideal electric field (electric flux) E that maintains parallel electric field lines can be generated in the central gap g (g1, g2) where the central electrode surface ELc through which current flows and the conductive material CD face each other.

[0132] As a result, as shown in Figure 1(A), it is possible to detect the capacitance Cx corresponding to an ideal parallel electric field (parallel plate capacitor) in the central gap g (g1, g2) between the center electrode surface ELc and the conductive material CD, which are commonly grounded and have opposing surfaces.

[0133] [Measurement of gap g] The present invention makes it possible to measure the gap g (g1, g2) between the center electrode surface ELc and the conductive material CD (measurement processing of the first electric field E1 by the measuring means 2) by utilizing the capacitance Cx of the capacitance body (ideal parallel electric field / predetermined electromagnetic field) generated in the gap g.

[0134] Specifically, the detection value Vm related to the capacitance body is given by the following equation (1) from Ohm's law for AC, where ω is the angular frequency of the current generated by the AC constant current source 3 and Cx is the capacitance applied to the first electric field E1. V m =I / (ωCx) …(1)

[0135] In addition, the capacitance Cx is expressed as follows: the gap g (g1, g2) applied to the first electric field E1 is g, the vacuum dielectric constant is ε0, and the relative dielectric constant applied to the first electric field E1 is ε S If the area of ​​the sensor surface 14 is A, it is given by the following equation (2). Cx=(ε0ε S A) / g …(2)

[0136] The gap g can be set to satisfy the following equation (3). g=ε0ε S A / Cx =[(ω×ε0ε S A) / I]×V m …(3)

[0137] Therefore, the reciprocal of the capacitance Cx is proportional to the gap g, and the following relationship (4) is obtained. 1 / Cx=g / (ε0ε S A)…(4)

[0138] Next, from the above equation (1) and the relationship that the reciprocal of the capacitance Cx is proportional to the gap g, the following equation (5) is obtained: Therefore, the above detection value Vm is a value proportional to the gap g. V m =I / (ωCx) =[I / (ωε0ε S A)]×g …(5)

[0139] In this embodiment, predetermined measurements relating to the gap g are possible based on the use of the detection value Vm proportional to the gap g.

[0140] Next, the second calculation unit 6 shown in FIG. 1A calculates the output voltage V out Furthermore, the impedance conversion circuit 5 including the amplifier 4 functions as a voltage buffer circuit, so that the output voltage V out is the input voltage V in The configuration is made to be equal to:

[0141] In this embodiment, the second calculation unit 6 is configured to obtain a second output value Vc relating to the capacitance output. The second output value Vc is a voltage component (capacitance Cx, output voltage V) relating to the first electric field E1 (charge, parallel electric field) that is affected by whether or not an insulating plate T (dielectric of a known thickness) is inserted into the gap g (g1, g2) that is positioned so that the opposing distance between the center electrode surface ELc and the conductive material CD can be freely changed. out ) is used to calculate the detected value Vm based on the correlation variable of the correlation (proportionality) between the thickness of the insulating plate T inserted in the gap g and the detection.

[0142] Next, when the influence of the stray capacitance C0 is not reduced, the detected value Vm is given by the following equation (6), where ω is the angular frequency of the current generated by the AC constant current source 3. V m =I / [ω(Cx+C0)] …(6)

[0143] Here, the capacitance Cx is calculated from the above equation (2) as follows: Cx = (ε0ε S Since it is given by "(A) / g", it can be transformed into the following equation (7). V m ={I / [ω(ε0ε S A+C0g)]}×g …(7) As can be seen from equation (7), when the influence of stray capacitance C0 is not reduced, the detected value Vm approaches Vm = I / (ωC0) (gradually approaches a constant value) as the gap g increases, and is not proportional to the gap g. As a result, when the gap g becomes large, it becomes impossible to measure the gap g based on the detected value Vm.

[0144] In this embodiment, the impedance conversion circuit 5 is provided to reduce the influence of the stray capacitance C0 present inside the amplifier etc. 4, so that "C0=0" can be satisfied.

[0145] Therefore, the above equation (7) can be changed to the following equation (8). V m ={I / [ω(ε0ε S A)]}×g …(8) As can be seen from equation (8), in this case, even if the gap g increases, the detection value Vm is proportional to the gap g.

[0146] As a result, even when the gap g (the distance between the commonly grounded probe body and the conductive object) is large, the above equation (3) "g = [(ω × ε0ε S A) / I]×V m ” can be used to measure the gap g based on the detected value Vm.

[0147] The second output value Vc relating to the capacitance output is determined based on the detection value Vm proportional to the gap g obtained by reducing the stray capacitance C0 present inside the amplifier 4 or the like.

[0148] [Configuration of eddy current measuring means 12] The eddy current measuring means 12 of the measuring means 2 shown in FIG. 1(A) is a schematic circuit diagram that includes a cable CV2 connected to the coil 18, an inductance (not shown), and a capacitance (not shown) to form an equivalent circuit (a specified eddy current displacement sensor).

[0149] The oscillator circuit (AC signal source) 8 shown in Fig. 1(A) includes an oscillator with a fixed frequency of about 1 to 3 GHz, such as a crystal oscillator. A high-frequency signal (with a frequency of 1 to 3 GHz) is obtained from the AC voltage generated by the oscillator circuit 8, and the high-frequency signal is supplied via a cable CV2 connected to a resonant circuit 19 (a component based on a coil 18 connected in parallel with a capacitor, not shown). Note that the cable CV2 may be configured as a coaxial cable CV2 with a shield braid, similar to the cable CV1.

[0150] 1A is a resistor R related to the resonant circuit 19. Note that this resistor R may be replaced with a capacitor, an inductor, or a combination of two or more of a resistor, a capacitor, and an inductor, thereby providing a modified configuration that reduces the coupling loss of the resonant circuit 19.

[0151] The rectifier circuit 9 shown in FIG. 1A is a circuit for rectifying a high-frequency signal that will flow in the resonant circuit 19 and the like.

[0152] 1A shows an amplifier circuit 10a that amplifies an input voltage V1. This amplifier circuit 10a includes a zero-shift circuit 10b that shifts the input voltage V1 by a predetermined voltage V2, an amplifier 10c connected downstream to set an amplification factor α, and a linearizer (not shown) that corrects and linearizes the nonlinearity of the output relative to the gap g. Based on the amplifier circuit 10a, an output voltage Vα can be output.

[0153] A coil 18, which is a component of a resonant circuit 19 shown in FIG. 1(A), is capable of generating a magnetic field (magnetic flux) Φ when it receives a high-frequency signal (electrical supply) from an oscillator circuit 8 via a cable CV2.

[0154] The magnetic field Φ generated by the coil 18 interlinks with the conductive material CD, and a mutual inductance is formed in the gap g1 between the coil 18 and the conductive material CD, which are commonly grounded and face each other. As a result, an eddy current ec is generated in the conductive material CD.

[0155] The eddy current ec generated in the conductive object CD is a vortex-shaped induced current caused by a magnetic field Φ generated in a gap g1 at a distance (measurement range, given distance) between the commonly grounded coil 18 (probe body 13, sensor part) and the conductive object CD, where the surfaces of the coil 18 and the conductive object CD face each other.

[0156] The eddy current measuring means 12 according to this embodiment has a circuit configuration that does not sense the thickness t of the insulating plate T, through which no current flows in principle. That is, in detecting a voltage component related to the magnetic field Φ (eddy current ec, magnetic quantity, magnetic charge, magnetic field) when an input voltage V1 is applied from the oscillator circuit 8 to the coil 18 via a resistor R, the eddy current measuring means 12 is configured to obtain detection results that are equivalent to those obtained when the gap g1 is not filled with the insulating plate T (hereinafter sometimes abbreviated as "not affected by the insertion"), even when the insulating plate T (dielectric of a known thickness) is inserted into a gap g1 (given distance, measurement range) that is appropriately determined by placing the coil 18 and the conductive material CD face to face.

[0157] In addition, the detection of the voltage component related to the magnetic field Φ that enables the above-mentioned output voltage Vα to be obtained may be performed based on a predetermined voltage component such as the resistance component or inductive reactance component of the impedance, utilizing the change in impedance of the resonant circuit 19 as seen from the oscillator circuit 8 caused by the generation of eddy current ec.

[0158] 1A according to the present embodiment, the first calculation unit 11 is configured to obtain a first output value Ve related to an eddy current output. This first output value Ve is related to a magnetic field Φ generated in a gap g1, which is positioned so that the distance between the coil 18 and the conductive object CD, which are opposed to each other, can be freely changed, and is calculated based on a detection result that determines a voltage component (eddy current) that is equivalent to that in the case of the gap g1 without the insulating plate T inserted in the gap g1, even when the insulating plate T is inserted in the gap g1, and is converted into a digital signal and analyzed, using an output voltage Vα that is obtained based on a proportionality constant of the correlation (proportionality) between the gap g1 and the detection.

[0159] From this, the output voltage Vα obtained from detecting the voltage component related to the magnetic field Φ in the gap g1 when the insulating plate T is not inserted is detected so that it is equal to the output voltage Vα obtained from detecting the voltage component related to the magnetic field Φ in the gap g1 when the insulating plate T is inserted.

[0160] Furthermore, the first output value Ve calculated using the output voltage Vα obtained from the gap g1 when the insulating plate T is not inserted can be treated equally to the first output value Ve calculated using the output voltage Vα obtained from the gap g1 when the insulating plate T is inserted.

[0161] [Measurement on insulating plate T inserted in gap g1] In this embodiment, when the spacing of the gap g1 without the insulating plate T inserted is displaced, the measurement means 2 is enabled to execute a measurement process for calculating a second output value Vc corresponding to the amount of displacement of the gap g1, using a value obtained from detecting a voltage component (capacitance Cx) related to the first electric field E1 generated in the displaced gap g1.

[0162] That is, the second output value Vc obtained by the second calculation unit 6 based on the detection of the voltage component related to the first electric field E1 in the gap g1 where the insulating plate T is not inserted can be calculated as a correlation variable based on the correlation between the gap g1 at that time and the detection.

[0163] In addition, in this embodiment, when the gap g2 shown in Figure 1(A) is displaced by individually inserting insulating plates T made of different predetermined plate thicknesses t, the measurement means 2 can execute a measurement process to calculate a second output value Vc corresponding to the amount of displacement of the gap g2 using a value obtained from detecting a voltage component related to the first electric field E1 generated in response to the displaced gap g2.

[0164] That is, the second output value Vc obtained by the second calculation unit 6 based on the detection of the voltage component related to the first electric field E1 in the gap g2 formed by the insertion of the insulating plate T can be calculated as a correlation variable of the correlation between the gap g2, which is the gap g1 minus the thickness of the insulating plate T at that time, and the detection.

[0165] Regarding the second output value Vc, the gap g2 applied to the first electric field E1 is defined as g, the proportional constant is defined as Kc, and the relative dielectric constant is defined as ε S and the thickness of the insulating plate T is t, the following equation (9) can be obtained. Vc=Kc{g+(t / ε S )} …(9)

[0166] Furthermore, in this embodiment, when the distance of the gap g1 is displaced, the measurement means 2 is enabled to execute a measurement process that calculates a first output value Ve corresponding to the amount of displacement of the gap g1, using a value obtained from detecting a voltage component (eddy current) that is related to the magnetic field Φ generated in the displaced gap g1 and is not affected by inserting an insulating plate T into the gap g1.

[0167] In other words, even when the insulating plate T is inserted to form a gap g2, the first calculation unit 11 is configured to calculate the first output value Ve, which is obtained based on the detection of a voltage component that is substantially equivalent to that related to the magnetic field Φ at the gap g1, as a proportionality constant based on the correlation between the gap g1 at this time and the detection.

[0168] Regarding the above first output value Ve, if the gap g2 across the magnetic field Φ is g, the proportionality constant is Ke, and the thickness of the insulating plate T is t, the following equation (10) can be obtained. Ve = Ke(g + t) …(10)

[0169] Next, when a gap g2 is formed by inserting the insulating plate T as shown in Figure 1(A), a difference process (Vc-Ve) is performed to subtract the first output value Ve from the second output value Vc, thereby deriving a difference value (correlation information) that is correlated (proportional) to the thickness displacement of the insulating plate T (the degree of thickness of the plate thickness t).

[0170] When performing the difference processing (Vc-Ve) according to this embodiment, the following equation (11) can be used. Vc-Ve=Kc{g+(t / ε S )}-Ke(g+t) =(Kc-Ke)g+{(Kc[t / ε S ])-(Ke×t)} =(Kc-Ke)g+{(Kc[1 / ε S ])-Ke}×t …(11)

[0171] In the measurement process of the measurement means 2 according to this embodiment, each output value (Vc or Ve) can be calculated by calculation using a detection related to the first electric field E1 generated in the gap g1 where the insulating plate T is not inserted and a proportional constant Kc calculated based on this detection, and a detection related to the magnetic field Φ generated in the gap g1 and a proportional constant Ke calculated based on this detection.

[0172] Furthermore, in this embodiment, the proportional constants Kc and Ke, which change proportionally according to the amount of displacement of the shared gap g1, are used to obtain the relationship "Kc = Ke," and the measurement process is designed to allow the specification of a coefficient (or group of coefficients) that can be considered to have the relationship "Kc = Ke = K (proportional constant)."

[0173] Based on the relationship that equates the proportional constant Kc and the proportional constant Ke, K (proportional constant) can be considered to be 1, and therefore the above equation (11) can be transformed into the following equation (12). Vc-Ve={(1 / ε S )-1}×(K×t) t=Vc-Ve / {(1 / ε S )-1} …(12)

[0174] Therefore, as can be seen from the above equation (12), the difference values ​​(Q1, Q2) derived from the above difference processing are the thickness t of the insulating plate T and {(1 / ε S )-1}.

[0175] Next, the procedure for deriving the difference value Q1 or the difference value Q2 according to this embodiment will be described with reference to FIG. 4 (graph lines S1 to S3).

[0176] The horizontal axis shown in Figure 4 is the gap g (g1, g2) that is determined so that the distance between the sensor surface 14 and the conductive material CD shown in Figure 1(A) can be freely changed by positioning them each time.

[0177] The gap g described below may be assumed to be in a state where an insulating plate T is inserted into the gap g. Therefore, in a non-inserted state where the insulating plate T is not inserted into the gap g, the gap g may be referred to as a given first distance (or gap g1) simply indicating the distance between the opposing surfaces. Furthermore, in a inserted state where the insulating plate T is inserted into the gap g, the gap g may be referred to as a given second distance (or gap g2) indicating the distance from the top surface of the insulating plate T to the sensor surface 14.

[0178] The vertical axis shown in Figure 4 represents the detection output Vx (or the first output value Ve) that forms the basis of the proportionality constant for the magnetic field generated in the gap g, or the detection output Vx (or the second output value Vc) that forms the basis of the correlation variable for the electric field generated in the gap g.

[0179] The proportional graph line S1 shown in Figure 4 represents the gain Ga0 of the correlation variable calculated as proportional slope information (capacitance output) that changes according to the correlation between a given first distance (gap g1) in a non-inserted state (without insulating plate T) and the second output value Vc obtained from detecting the electric field (capacitance) at that time, and also represents the gain Gb of the proportional constant calculated as proportional slope information (eddy current output) that changes according to the correlation between the same given first distance (shared gap g1) and the first output value Ve obtained from detecting the magnetic field (eddy current) generated at that time.

[0180] The graph line S1 in this embodiment can show the progression (standard proportional slope information in this embodiment) of the gain (gain Gb = gain Ga0) that is regarded as an index of equivalence (Vc = Ve) based on the balance of proportional changes according to the shared gap g1 between gain Gb and gain Ga0.

[0181] From this, when the differential processing (second output value Vc - first output value Ve) is performed in the non-insertion state described above, the result is a measurement process (calculation, processing) that obtains a differential value of 0 (correlation information related to no insulating plate (Null)).

[0182] Next, the proportional graph line S2 shown in FIG. 4 represents the gain Ga1 of the correlation variable calculated as proportional slope information (capacitance output) that shifts (parallel movement displaced based on the transition of one Vc) from the graph line S1 (gain Gb=Ga0) in accordance with a predetermined influence (Vc≠Ve) of the thickness t of the insulating plate T1 (thickness of the object to be measured, dielectric) when a predetermined second distance (gap g2) is inserted as shown in FIG. 1(A).

[0183] The graph line S2 in this embodiment represents the gain Ga1 of the correlation variable (second output value) that changes according to the correlation with the plate thickness t of the insulating plate T1, which is obtained based on the detection of the electric field generated at a given second distance (gap g2), and can also show a progression as proportional slope information (gain Ga1) that shifts the graph line S1 by a predetermined amount due to the plate thickness t.

[0184] And in the measuring means 2 according to the present embodiment, when a detection state is obtained in which a predetermined graph line S2 (in the state where the insulating plate is inserted), which is a shift with respect to the graph line S1 of the reference (state where the insulating plate is not inserted), or a graph line S3 described later is obtained, the development of the measurement process including the conditional processing for determining that the predetermined measurement conditions are satisfied proceeds.

[0185] As a specific example, in the measurement process when the above conditional processing is satisfied, a first process for obtaining a first output value Ve0 illustrated in the graph line S1 of FIG. 4 as an index Ve0 (first calculation information) is performed, and a second process for specifying a second output value Vc1, which is a shift from the index Ve0 shown in the graph line S2 of FIG. 4 (second calculation information), is performed, and a difference process (subtraction of Vc1 - Ve0) for calculating the difference (shift amount, correlation information) of the values obtained based on the establishment of the first process and the second process is executed so that the measurement process can be performed.

[0186] And the above measurement process can determine the measured value (the plate thickness t of the insulating plate T1) by performing a reference process using the stored thickness information (table setting) numerically converted in advance based on a known measured object (insulating plate) as calibration (measurement adjustment for matching the reference) from the difference value Q1 calculated from the above difference process.

[0187] Next, the proportional graph line S3 shown in FIG. 4 is in the case where a given second distance (gap g2) with a predetermined insulating plate T2 (T1 < T2) as shown in FIG. 1(A) is inserted, and represents a gain Ga2 of a correlation variable that is determined as proportional inclination information that shifts by a predetermined influence corresponding to the plate thickness t of the insulating plate T2 from the graph line S1.

[0188] The graph line S3 in this embodiment represents the gain Ga2 of the correlation variable (second output value) that changes according to the correlation with the plate thickness t of the insulating plate T2, which is obtained based on the detection of the electric field generated at a given second distance (gap g2), and can also show a progression as proportional slope information (gain Ga2) that shifts the graph line S1 by a predetermined amount due to the plate thickness t.

[0189] As another specific example, in the measurement process when the above condition processing is satisfied, a first process is performed to obtain the first output value Ve0 illustrated in graph line S1 of Figure 4 as an index Ve0, a second process is performed to determine the second output value Vc2 which is a shift from the index Ve0 illustrated in graph line S3 of Figure 4, and a difference process (subtraction of Vc2 - Ve0) is performed to calculate the difference between the values ​​obtained based on the establishment of the first process and the second process.

[0190] The above measurement process then performs a reference process using stored thickness information that has been previously quantified based on a known object to be measured as calibration from the difference value Q2 calculated from the above-mentioned difference process, thereby determining the measurement value (thickness t of insulating plate T2).

[0191] The present invention has been described above based on the preferred embodiment, but the present invention is not limited to the above embodiment and various modifications are possible without departing from the gist of the present invention.

[0192] The center electrode surface ELc and the guard electrode surface ELg according to this embodiment may be formed on only one surface of a single predetermined substrate, or may be formed on both surfaces of a single predetermined substrate. Alternatively, the probe substrate 15 may be formed solely of a first layer substrate 16 having the center electrode surface ELc and the guard electrode surface ELg. Alternatively, the probe substrate 15 may be formed by laminating the first layer substrate 16 and the second layer substrate 17. Alternatively, the probe substrate 15 may be formed by laminating the first layer substrate 16 and the third layer substrate 60. Alternatively, the first layer substrate 16, the second layer substrate 17, and the third layer substrate 60 may be stacked with gaps between them at their opposing portions.

[0193] 1(A) may be configured to be an integral bundle so that the cables CV1 and CV2 do not electrically affect each other, allowing for the routing and movement of the probe body 13. Alternatively, the cables CV1 and CV2 may be configured to extend independently and in parallel so that they do not electrically affect each other, allowing for the routing and movement of the probe body 13.

[0194] The eddy current measuring means 12 of this embodiment generates a magnetic field (high frequency magnetic field Φ) by irradiating magnetic field lines from the coil 18, causes eddy currents ec to be formed in the conductive material CD based on the generation of the magnetic field, and makes it possible to detect the amount of change in the magnetic field corresponding to the eddy current loss caused by the formation of the eddy currents ec as the sheet resistance of the conductive material CD.

[0195] Specifically, when a coil 18 with an AC voltage applied is brought close to a conductive object CD, a voltage is generated in the conductive object CD due to electromagnetic induction, causing an AC current (induced current) to flow, generating a so-called eddy current ec. The generation of the eddy current ec disrupts the resonance state of the closed circuit, causing a change in the magnetic field generated by the coil 18 in the closed circuit. The impedance (equivalent to the resistance of a DC circuit) of the coil 18 changes in response to the change in the magnetic field. This principle is used to measure the sheet resistance of the object to be measured. The magnitude of the eddy current ec is determined by the given distance related to the gap g to be measured and the material and size of the object to be measured (dielectric).

[0196] The amount of change in the magnetic field may be obtained by assuming that a resistance equivalent to the eddy current loss is added in series or in parallel to a series resonant circuit including the coil 18.

[0197] The magnetic field can be acquired as 1) the amount of change in impedance, 2) the amount of change in inductance, 3) the amount of change in capacitance, and 4) the amount of change in resonance frequency in the resonance circuit 19. That is, a change in the magnetic field of the coil 18 disrupts the resonance state of the resonance circuit 19, and this is reflected in the output detection signal. By reading this as an indication of the sheet resistance of the object to be measured, the sheet resistance value (first detection value) can be calculated.

[0198] Furthermore, an operational amplifier may be provided to convert the detection signal (signal voltage) acquired by the eddy current measuring means 12 from the probe body 13 into a 1:1 amplified signal, convert this amplified signal into an effective DC voltage value as the detection result, and output this converted DC voltage value to an A / D converter (not shown).

[0199] Specifically, the amplifier may be configured to include a high-frequency AC oscillation circuit (not shown) connected to the coil 18, and a detection circuit (not shown) that separates the required signal wave (voltage value) from the modulated wave from the high-frequency AC oscillation circuit.

[0200] That is, the generated eddy current ec becomes Joule heat and is consumed, resulting in a loss of power (eddy current loss). The amount of change in the magnetic field of coil 18 corresponding to the eddy current loss may be obtained by eddy current measurement means 12 as the difference between the high frequency power supplied to coil 18 and the high frequency power returned from coil 18, and based on this, the amplifier may output a detection signal (signal voltage).

[0201] Furthermore, the change in high frequency power may be input as a modulated wave from the high frequency AC oscillator circuit to a detection circuit, where the detection circuit separates a signal wave from the modulated wave, converts the signal wave into a DC voltage value, and outputs the voltage signal (first detection value) to a predetermined A / D converter (not shown).

[0202] Furthermore, with regard to the rectifier circuit 9 (diode rectification) shown in Fig. 1(A), either full-wave rectification or half-wave rectification may be used as a rectification method for converting an alternating current (AC) voltage into a direct current (DC) voltage. Also, a modified configuration may be adopted in which the rectifier circuit 9 shown in Fig. 1(A) is not provided.

[0203] In order to achieve the above object, a non-contact sensor device according to a modified example of the present invention comprises: A sensor device having a probe unit, a detection unit, and a measurement processing unit, which performs non-contact thickness measurement of an object to be measured when the object to be measured is inserted into a gap where the probe unit and a given conductive object face each other, The aforementioned probe section is a probe substrate having a predetermined surface for facing the conductive object and at least forming an annular electrode surrounding a central surface area of ​​the predetermined surface, and a coil overlapping the central surface area and extending in a direction away from the conductive object, wherein a magnetic field is generated in the gap based on the supply of electricity to the electrode and the coil, and an electric field surrounding the magnetic field is generated in the gap; The aforementioned measurement processing unit is The device may be configured to be able to measure thickness by determining correlation information calculated based on a first detection value related to the magnetic field in the gap and a second detection value related to the electric field in the gap, which are detected by the detection unit when the object to be measured is inserted into the gap, and a coefficient correlating with the thickness of the object to be measured.

[0204] Furthermore, in order to achieve the above object, a non-contact sensor device according to a modified example of the present invention comprises: The probe substrate is forming an annular pattern electrode that is divided into a first annular electrode and inner and outer second electrodes that concentrically surround the inside and outside of the first electrode, respectively; a first electric field generated based on the supply of electricity to the first electrode is located in the annular central portion, and second electric fields are generated by the annular inner portion and the annular outer portion based on the supply of electricity to the inner and outer second electrodes, respectively, to sandwich the first electric field in the gap; The above detection unit is The second detection value may be detected as being related to the first electric field in the annular central portion.

[0205] Furthermore, in order to achieve the above object, a non-contact sensor device according to a modified example of the present invention comprises: The probe part is a ring-shaped probe base material surrounding a central surface region in the predetermined plane as a hollow portion; a coil that is overlapped so that an opening facing the conductive material is accommodated within the hollow portion; The housing is formed to accommodate the When viewed from the predetermined surface toward the coil, an annular gap may be provided between the hollow portion of the annular probe base and the opening of the coil.

[0206] Furthermore, in order to achieve the above object, a non-contact sensor device according to a modified example of the present invention comprises: The measurement processing unit is a coefficient in a first coefficient section that previously obtains a correlation between a given distance between the probe portion and the surface of the conductive object facing each other in the gap and a first detection value related to the magnetic field corresponding to the given distance; a coefficient in a second coefficient section obtained by calculating a correlation between the thickness of the object to be measured and the second detection value from a second detection value related to an electric field obtained by inserting an object to be measured having a known thickness into the gap; and a process for using the a process of determining correlation information correlating with the thickness of the object to be measured of unknown thickness from a first detection value related to the current magnetic field and a second detection value related to the current electric field detected when the object to be measured of unknown thickness is inserted into the gap, and the coefficients in the first coefficient section and the second coefficient section; The above configuration may be adopted.

[0207] Furthermore, in order to achieve the above object, a non-contact sensor device according to a modified example of the present invention comprises: The measurement processing unit is When a measurement object of unknown thickness is inserted into a given distance (gap), a first detection value related to the current magnetic field and a second detection value related to the current electric field are obtained from the detection unit, calculating a first output value by an operation using the first detected value and a coefficient in the first coefficient unit; calculating a second output value by an operation using the second detection value and a coefficient in the second coefficient unit; The apparatus may be configured to perform processing for determining the correlation information from a difference based on the first output value and the second output value.

[0208] In addition, as a modified example of the present invention, in order to achieve the above object, A measurement method comprising a probe unit, a detection unit, and a measurement processing unit, for non-contact thickness measurement of an object to be measured when the object to be measured is inserted into a gap where the probe unit and a given conductive object face each other, the method comprising: The aforementioned probe section is The magnet has electrodes and coils, and an electric field and a magnetic field can be generated in the gap by supplying electricity to the electrodes and coils; The aforementioned detection unit is a first detection value related to at least one of a voltage, a current, a frequency, and a phase in a magnetic field; a second detection value related to at least one of a voltage, a current, a frequency, and a phase in the electric field; to be able to detect The aforementioned measurement processing unit is a setting step for using a first coefficient obtained in advance based on a correlation between a given distance between the opposing surfaces in the gap and a first detection value obtained in accordance with the given distance; a step of setting a second coefficient obtained by previously calculating a correlation between the thickness of the object to be measured and the second detection value obtained by inserting the object to be measured having a known thickness into the gap; a step of calculating correlation information based on the first detection value and the second detection value detected when an object to be measured having an unknown thickness is inserted at the given distance, the first coefficient, and the second coefficient, and performing thickness measurement; The measurement method may be configured to include the following.

[0209] Furthermore, the present invention can be configured in such a way that a measurement value corresponding to the thickness of an object to be measured can be calculated with high accuracy even when the probe body 13 is installed by a machine or an operator with low precision in positioning the sensor surface relative to the conductive object. Therefore, the method of positioning the sensor surface 14 of the probe body 13 so that it faces the conductive object may be performed not only by an operator holding and pulling the probe body 13, but also by attaching the probe body 13 to the tip (end effector) of a robot arm that is controlled to move in two or three dimensions and pulling the probe body 13 by the robot arm. [Industrial Applicability]

[0210] As an example of the use of the present invention, it can be applied to a sensor device that non-contactly measures the thickness of a measurement object (insulating plate T) inserted into a gap between the sensor surface (probe portion) of the probe body and an opposing conductive object.

[0211] The present invention may also be applied to laser processing devices that use gap measurement, liquid crystal inspection devices, disk runout measurement devices, devices that measure wafer thickness flatness, devices that perform positioning control for measuring stage movement amounts, etc. The present invention may also be applied to various copying devices that use gap measurement. [Explanation of symbols]

[0212] 1. Non-contact sensor device 2. Measurement methods 3 … AC constant current source 4... Amplifiers, etc. 5... Impedance conversion circuit 6 ... Second calculation section 7...Capacitive measurement means 8...Oscillator circuit 9 … Rectifier circuit 10a... Amplification circuit 10b... Zero shift circuit 10c... Amplifier 11 ... Second calculation unit 12... Eddy current measuring means 13 ... probe body 14 ... sensor surface 15 ... Probe board 16...1st layer board 17...2nd layer board 18... Coil 19 … Resonant circuit 20...Third insulated wire 21 ... First insulated wire 22... inner segment electrodes 23... Center through hole 24a, 24b, 24c... Second insulated wire 25... Outer segment electrode 25b... 1st outer section surface 25c... 2nd outer section 28 ... Electrode surface near the periphery 29 ... Electrode surface near the inner circumference 58... Coil 59 … Resonant circuit 60...3rd layer board CV...Cable section (CV1, CV2) CD: Conductive material Cx: capacitance E1: First electric field E2: Second electric field ELc … Center electrode surface ELg: Guard electrode surface ec … eddy current g...gap I … constant current T...insulating plate Φ...magnetic field (high frequency magnetic field, magnetic flux, magnetic lines of force)

Claims

1. A sensor device having a probe unit, a detection unit, and a measurement processing unit, which performs non-contact thickness measurement of an object to be measured when the object to be measured is inserted into a gap where the probe unit and a given conductive object face each other, The probe unit includes: a housing having a predetermined surface facing the conductive material, an electrode disposed on the predetermined surface, and a coil disposed on the electrode and extending in a direction away from the conductive material, The predetermined surface is a sensor surface having a common surface area that generates an electric field and a magnetic field in the gap based on an electrical supply to the electrode and the coil; The measurement processing unit A sensor device characterized in that it is capable of measuring the thickness by calculating correlation information based on a first detection value related to the magnetic field and a second detection value related to the electric field detected by the detection unit when the object to be measured is inserted into the gap, and a coefficient correlating with the thickness of the object to be measured.

2. The electrode is the probe base material is disposed on the predetermined surface of the probe portion, the probe base material having: a first electrode capable of generating a first electric field in a central surface region of the sensor surface; a second electrode capable of generating a second electric field so as to surround the first electric field in a non-central surface region of the sensor surface; and insulating portions provided on the first electrode and the second electrode, The insulating portion is an insulating linear path that separates each of the first electrode and the second electrode into a plurality of segmented electrodes; and a small electrode path connecting some of the segmented electrodes, Each of the first electrode and the second electrode is The sensor device according to claim 1, characterized in that the insulating linear path and the small electrode path form an open loop pattern that suppresses the flow of induced currents that may occur in the central plane region and the non-central plane region due to the magnetic field.

3. The probe substrate is a second layer substrate laminated on a first layer substrate on which the patterned first electrode and the second electrode are provided, The second layer substrate comprises: the first electrode for overlapping and covering the insulating portion disposed in a central surface region of the sensor surface; the second electrode for overlapping and covering the insulating portion disposed in a non-central surface region of the sensor surface; 3. The sensor device according to claim 2, further comprising:

4. The probe substrate is a third layer substrate disposed so as to overlap the first layer substrate on which the first electrode related to the electrical supply on the input side and the second electrode related to the electrical supply on the output side are provided, The third layer substrate is The sensor device according to claim 2, characterized in that a second electrode is provided which is arranged to overlap and cover the first electrode and the second electrode provided on the first layer substrate, and which is related to the electrical supply on the output side.

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