JP2013181810A - Method of detecting conductive film, conductive film sensor, and method for setting magnetic field frequency of conductive film sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor capable of specifying the position of a conductive film with a conductor disposed on its backside.SOLUTION: A conductive film sensor comprises: a frequency specification part 302 for acquiring Q-values when radiating a plurality of magnetic fields having different frequencies from a magnetic field radiator 1 to a sample conductive film 3 with a sample conductor 2 disposed on its backside while changing an interval between the sample conductor 2 and the sample conductive film 3, and specifying a frequency having the smallest variations in the Q-value; a relation acquisition part 303 for acquiring a relation between the position of the sample conductive film 3 and the Q-value when irradiating the sample conductive film 3 with a magnetic field of the specified frequency; and a position specification part 305 for radiating the magnetic field of the specified frequency from the magnetic field radiator 1 to a measuring object conductive film with the conductor 2 disposed on its backside to measure a Q-value, and specifying the position of the measuring object conductive film on the basis of the relation and a measured Q-value.

Description

  The present invention relates to a detection technique, and relates to a method for detecting a conductive film, a conductive film sensor, and a method for setting a magnetic field frequency of the conductive film sensor.

  When a magnetic field is excited by a coil and a magnetic film is irradiated on a conductive film such as a metal film, an eddy current is generated in the conductive film. Here, when the distance between the coil and the conductive film is changed by electromagnetic induction, the electrical characteristics such as the Q value and impedance of the coil change. Therefore, if the relationship between the distance between the conductive film and the coil and the electrical characteristics of the coil is acquired in advance, the measurement is performed from the value of the electrical characteristics of the coil when the magnetic film is irradiated to the measurement target conductive film. It is possible to calculate the position of the target conductive film (see, for example, Patent Document 1).

JP 2010-164472 A

  However, when a conductor is disposed behind the conductive film, when a magnetic field is excited from the coil, an eddy current is generated in both the conductive film and the conductor. Therefore, there is a problem that neither the conductive film nor the conductor can be accurately detected. Therefore, the present invention provides a method for detecting a conductive film, a conductive film sensor, and a method for setting a magnetic field frequency of the conductive film sensor that can specify the position of a conductive film having a conductor disposed behind. One of the purposes.

  According to an aspect of the present invention, (a) a magnetic field radiator is disposed toward a sample conductive film having a sample conductor disposed behind, and (b) a distance between the sample conductive film and the sample conductor. , Radiating a plurality of magnetic fields with different frequencies from the magnetic field emitter toward the sample conductive film, measuring the resistance or quality factor of the magnetic field radiator, and (c) changing the interval Identifying the frequency of the magnetic field with the least variation in resistance or quality factor, and (d) the position of the sample conductive film and the resistance when the magnetic field of the specified frequency is irradiated toward the sample conductive film. Or obtaining a relationship with the quality factor, (e) disposing a magnetic field emitter toward the conductive film to be measured with a conductor disposed behind, and (f) conducting the measurement object. Radiating a magnetic field of a specified frequency toward the film and measuring the resistance or quality factor of the magnetic field emitter; (g) relationship and resistance when radiating the magnetic field toward the conductive film to be measured Alternatively, a method for detecting a conductive film is provided, which includes specifying a position of a conductive film to be measured based on a measurement value of a quality factor.

  Further, according to the aspect of the present invention, the sample conduction is directed to (a) a magnetic field radiator that radiates a plurality of magnetic fields having different frequencies, and (b) a sample conductive film having a sample conductor disposed behind. A characteristic acquisition unit for acquiring the resistance or quality factor of the magnetic field emitter when a plurality of magnetic fields are radiated from the magnetic field radiator while changing the distance between the conductive film and the sample conductor; and (c) when the interval is changed. A frequency specifying unit that specifies the frequency of the magnetic field having the least variation in resistance or quality factor; and (d) the position of the sample conductive film when the magnetic field having the specified frequency is irradiated toward the sample conductive film. A relationship acquisition unit for acquiring the relationship between the resistance or the quality factor, and (e) the frequency specified from the magnetic field emitter toward the conductive film to be measured with the conductor disposed behind. A measurement unit that radiates the field and measures the resistance or quality factor of the magnetic field radiator; and (f) the relationship and the measured value of the resistance or quality factor when the magnetic field is radiated toward the conductive film to be measured. A conductive film sensor is provided that includes a position specifying unit that specifies the position of the conductive film to be measured.

  Further, according to an aspect of the present invention, (a) a magnetic field radiator is disposed toward a sample conductive film having a sample conductor disposed behind, and (b) the sample conductive film and the sample conductor are disposed. The magnetic field radiator emits a plurality of magnetic fields each having a different frequency toward the sample conductive film while changing the interval, and the resistance or quality factor of the magnetic field emitter is measured, and (c) the interval is changed. And determining the frequency of the magnetic field with the least variation in resistance or quality factor, and a method for setting the magnetic field frequency of the conductive film sensor is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the detection method of the conductive film which can pinpoint the position of the conductive film with which the conductor is arrange | positioned in the back, a conductive film sensor, and the setting method of the magnetic field frequency of a conductive film sensor can be provided. .

It is a 1st schematic diagram of the electroconductive film sensor which concerns on the 1st Embodiment of this invention. It is a 2nd schematic diagram of the electroconductive film sensor which concerns on the 1st Embodiment of this invention. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of frequency 10kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 10kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of frequency 200kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 200kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the variation | change_quantity of the Q value of a coil accompanying the change of the space | interval of the sample conductor and sample conductive film which concern on the 1st Embodiment of this invention. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of frequency 10kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of frequency 200kHz which concerns on the 1st Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of the frequency of 120 kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 120kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the resistance of a coil at the time of irradiating the magnetic field of frequency 300kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the Q value of a coil at the time of irradiating the magnetic field of frequency 300kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the variation | change_quantity of the Q value of a coil accompanying the change of the space | interval of the sample conductor and sample conductive film which concern on the 2nd Embodiment of this invention. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of frequency 50kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of the frequency of 120 kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample electroconductive film. It is a graph which shows the relationship between the inductance of a coil at the time of irradiating the magnetic field of frequency 300kHz which concerns on the 2nd Embodiment of this invention, and the distance between a coil and a sample conductive film. It is a schematic diagram of the electroconductive film sensor which concerns on other embodiment of this invention.

  Embodiments of the present invention will be described below. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, the drawings are schematic. Therefore, specific dimensions and the like should be determined in light of the following description. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

(First embodiment)
As shown in FIG. 1, the conductive film sensor according to the first embodiment includes a magnetic field radiator 1 that emits a plurality of magnetic fields having different frequencies, and a central processing unit connected to the magnetic field radiator 1 ( CPU) 300. The CPU 300 includes a characteristic acquisition unit 301, a frequency identification unit 302, and a relationship acquisition unit 303. The characteristic acquisition unit 301 changes a plurality of magnetic fields from the magnetic field radiator 1 while changing the distance M between the sample conductive film 3 and the sample conductor 2 toward the sample conductive film 3 on which the sample conductor 2 is disposed behind. The value of the resistance or the quality factor of the magnetic field radiator 1 (hereinafter referred to as “Q value” or “Q value”) is acquired. The frequency specifying unit 302 specifies the frequency of the magnetic field with the least variation in the resistance value or Q value of the magnetic field radiator 1 when the distance M between the sample conductive film 3 and the sample conductor 2 is changed.

  The relationship acquisition unit 303 indicates the relationship between the position of the sample conductive film 3 and the resistance or Q value when the magnetic field having the frequency specified by the frequency specifying unit 302 is irradiated toward the sample conductive film 3. get. Here, the position of the sample conductive film 3 is, for example, a relative position of the front surface or the back surface of the sample conductive film 3 with respect to the magnetic field radiator 1, and more specifically, a distance D from the magnetic field radiator 1. is there.

  CPU 300 further includes a measurement unit 304 and a position specifying unit 305. As shown in FIG. 2, the measuring unit 304 radiates a magnetic field having a frequency specified by the frequency specifying unit 302 from the magnetic field radiator 1 toward the measurement target conductive film 5 in which the conductor 4 is arranged behind. In this case, the resistance value or Q value of the magnetic field radiator 1 is measured. The position specifying unit 305 measures the relationship acquired by the relationship acquiring unit 303 and the resistance of the magnetic field radiator 1 when the magnetic field having the frequency specified by the frequency specifying unit 302 is radiated toward the measurement target conductive film 5. The position of the conductive film 5 to be measured is specified based on the value or the measured value of Q. Here, the position of the measurement target conductive film 5 is, for example, the relative position of the front or back surface of the measurement target conductive film 5 with respect to the magnetic field radiator 1, and more specifically, the distance from the magnetic field radiator 1. D.

  The magnetic field radiator 1 shown in FIGS. 1 and 2 has a coil 11. The coil 11 radiates, for example, a first magnetic field, a second magnetic field, and a third magnetic field, each having a different frequency, with a changeover switch. Alternatively, the first magnetic field, the second magnetic field, and the third magnetic field, each having a different frequency, are radiated alternately every predetermined time or every predetermined wave number.

The sample conductor 2 shown in FIG. 1 is made of, for example, a magnetic material such as iron, or a nonmagnetic material such as aluminum, copper, or an alloy containing these predominantly. The sample conductive film 3 is made of, for example, a nonmagnetic material such as aluminum, copper, or an alloy mainly containing these. The coil 11 forms a part of the LC oscillation circuit. The LC oscillation circuit is configured such that the oscillation amplitude is a monotone function of the Q value of the coil 11. The Q value of the coil 11 is given by the following equation (1), where ω is the resonance angular frequency, L is the self-inductance of the coil 11, and R is the resistance of the coil 11.
Q = ωL / R (1)

  Along with the oscillation of the LC oscillation circuit, a high-frequency AC magnetic field is formed from the coil 11 toward the sample conductive film 3 and the sample conductor 2, and eddy currents are generated in the sample conductive film 3 and the sample conductor 2, respectively. . The loss of electrical energy due to the eddy current increases the apparent resistance R of the coil 11 and decreases the Q value. The change in the resistance value R or Q value of the coil depends on the distance D from the magnetic field radiator 1 to the sample conductive film 3 and the interval M between the sample conductive film 3 and the sample conductor 2.

  Here, as an example, the magnetic field radiator 1 irradiates the sample conductive film 3 and the sample conductor 2 with a first magnetic field of 10 kHz as the first frequency from the coil 11, and the measured value of the resistance R of the coil 11 or The measured value of Q is transmitted to the characteristic acquisition unit 301. FIG. 3 shows that the distance M between the sample conductive film 3 made of aluminum having a thickness of 10 μm and the sample conductor 2 made of aluminum having a thickness of 10 mm is 5 μm, 25 μm, 50 μm, 75 μm, 100 μm, 500 μm, and 1000 μm. When the first magnetic field of 10 kHz is radiated from the coil 11, the distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 and the measured value of the resistance R of the coil 11 It is a graph which shows an example of a relationship. FIG. 4 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  Further, as an example, the magnetic field radiator 1 shown in FIG. 1 irradiates the sample conductive film 3 and the sample conductor 2 with a second magnetic field of 50 kHz as the second frequency from the coil 11, and the resistance R of the coil 11 is reduced. The measured value or the measured value of Q is transmitted to the characteristic acquisition unit 301. FIG. 5 shows that the distance M between the sample conductive film 3 made of aluminum having a thickness of 10 μm and the sample conductor 2 made of aluminum having a thickness of 10 mm is set to 5 μm, 25 μm, 50 μm, 75 μm, 100 μm, 500 μm, and 1000 μm. When the second magnetic field of 50 kHz is emitted from the coil 11, the distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 and the measured value of the resistance R of the coil 11 It is a graph which shows an example of a relationship. FIG. 6 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  Further, as an example, the magnetic field radiator 1 shown in FIG. 1 irradiates the sample conductive film 3 and the sample conductor 2 with a third magnetic field of 200 kHz as the third frequency from the coil 11, and the resistance R of the coil 11 is reduced. The measured value or the measured value of Q is transmitted to the characteristic acquisition unit 301. FIG. 7 shows that the distance M between the sample conductive film 3 made of aluminum having a thickness of 10 μm and the sample conductor 2 made of aluminum having a thickness of 10 mm is 5 μm, 25 μm, 50 μm, 75 μm, 100 μm, 500 μm, and 1000 μm. When the third magnetic field of 200 kHz is radiated from the coil 11, the distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 and the measured value of the resistance R of the coil 11 It is a graph which shows an example of a relationship. FIG. 8 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  When the sample conductor 2 and the sample conductive film 3 shown in FIG. 1 are irradiated with a magnetic field, the eddy current loss in the sample conductor 2 decreases as the distance M between the sample conductor 2 and the sample conductive film 3 increases. To do. However, in this case, since the demagnetizing field generated in the sample conductor 2 is reduced, the eddy current loss in the sample conductive film 3 is increased.

  Here, when the frequency of the magnetic field irradiated to the sample conductor 2 and the sample conductive film 3 is increased, the increase amount of the eddy current loss in the sample conductive film 3 is larger than the decrease amount of the eddy current loss in the sample conductor 2. Become bigger. Accordingly, when the frequency of the magnetic field applied to the sample conductor 2 and the sample conductive film 3 is high, the sample conductor 2 and the sample conductivity are increased as the distance M between the sample conductor 2 and the sample conductive film 3 increases. The eddy current loss in the entire film 3 increases, the value of the resistance R of the coil 11 increases as shown in FIG. 7, and the Q value of the coil 11 tends to decrease as shown in FIG.

  On the other hand, as the frequency of the magnetic field applied to the sample conductor 2 and the sample conductive film 3 decreases, the increase in eddy current loss in the sample conductive film 3 is smaller than the decrease in eddy current loss in the sample conductor 2. Become smaller. Therefore, when the frequency of the magnetic field applied to the sample conductor 2 and the sample conductive film 3 is low, the sample conductor 2 and the sample conductivity are increased as the distance M between the sample conductor 2 and the sample conductive film 3 increases. The eddy current loss in the entire film 3 decreases, the value of the resistance R of the coil 11 decreases as shown in FIG. 3, and the Q value of the coil 11 tends to increase as shown in FIG.

  However, if the frequency of the magnetic field applied to the sample conductor 2 and the sample conductive film 3 is set to an appropriate value, the amount of decrease in eddy current loss in the sample conductor 2 due to the frequency of the magnetic field and the interval M The amount of increase in eddy current loss in the sample conductive film 3 is substantially equal. In this case, the change in the eddy current loss in the entire sample conductor 2 and the sample conductive film 3 due to the change in the distance M between the sample conductor 2 and the sample conductive film 3 is suppressed. Therefore, as shown in FIG. 5, the change in the value of the resistance R of the coil 11 due to the change in the interval M is also suppressed, and as shown in FIG. . In this case, the resistance R value and Q value of the coil 11 change mainly according to the distance D from the magnetic field radiator 1 to the sample conductive film 3.

  FIG. 9 shows an example of the amount of change in the Q value when the distance D from the magnetic field radiator 1 to the sample conductive film 3 is 2 mm and the distance M between the sample conductor 2 and the sample conductive film 3 is changed. It is a graph to show. As shown in FIG. 9, when the frequency of the magnetic field is 50 kHz, the amount of change in the Q value is the smallest. In this case, the frequency specifying unit 302 shown in FIG. 1 specifies 50 kHz as the frequency of the magnetic field with the smallest variation in the Q value of the coil 11 that occurs when the interval M changes. The frequency specifying unit 302 may specify 50 kHz as the frequency of the magnetic field having the smallest variation in the resistance R value of the coil 11 that occurs when the interval M changes. In addition, the frequency specifying unit 302 may provide a predetermined threshold value and specify a frequency at which the variation of the resistance R or the Q value of the coil 11 falls within the threshold value.

  10 to 12 are graphs when the inductance L of the coil 11 is measured under the same conditions as those for creating the graphs of FIGS. 3 to 9. As shown in FIGS. 10 to 12, the inductance L of the coil 11 is affected by the change in the interval M regardless of the value of the frequency of the magnetic field applied to the sample conductor 2 and the sample conductive film 3. Therefore, the frequency specifying unit 302 shown in FIG. 1 cannot specify the frequency of the magnetic field that is not affected by the change in the interval M, based on the inductance L of the coil 11.

  The relationship acquisition unit 303 shown in FIG. 1 takes, for example, an average value of the resistance R of the coil 11 with respect to the distance D from the magnetic field radiator 1 to the sample conductive film 3 shown in FIG. From this, a relational expression that uniquely determines the distance D is calculated. Alternatively, the relationship acquisition unit 303 may calculate a table in which the distance D is uniquely determined from the value of the resistance R of the coil 11. Alternatively, for example, the relationship acquisition unit 303 takes the average of the Q values of the coil 11 with respect to the distance D shown in FIG. 6 and calculates a relational expression or table that uniquely determines the distance D from the Q value of the coil 11. The relationship acquisition unit 303 illustrated in FIG. 1 stores the calculated relationship formula or table in the relationship storage device 401.

  Next, as shown in FIG. 2, the conductive film 5 to be measured with the conductor 4 disposed behind is disposed in front of the conductive film sensor according to the first embodiment. The conductor 4 is made of substantially the same material as the sample conductor 2 shown in FIG. The conductor 4 may have substantially the same thickness as the sample conductor 2, or may have a different thickness. However, the thicknesses of the conductor 4 and the sample conductor 2 are sufficiently thicker than the skin depth for the specified frequency so as not to be affected by the difference in thickness. The measurement target conductive film 5 shown in FIG. 2 has substantially the same thickness as the sample conductive film 3 shown in FIG. 1 and is made of substantially the same material. Here, the distance D from the magnetic field radiator 1 to the measurement target conductive film 5 shown in FIG. 2 is the measurement target, and the interval M between the conductor 4 and the measurement target conductive film 5 is unknown and can vary.

  The measurement unit 304 irradiates the measurement target conductive film 5 and the conductor 4 with the magnetic field of, for example, 50 kHz specified by the frequency specification unit 302 via the magnetic field radiator 1, and measures the measured value of the resistance R or Q of the coil 11. Measure the measured value. The measuring unit 304 transmits the measured value of the resistance R or the measured value of Q of the coil 11 to the position specifying unit 305.

  The position specifying unit 305 receives the measured value of the resistance R or the measured value of Q of the coil 11 when the measuring target conductive film 5 and the conductor 4 are irradiated with the magnetic field of 50 kHz from the measuring unit 304. Further, the position specifying unit 305 reads the relationship between the resistance R of the coil 11 and the distance D or the relationship between the Q of the coil 11 and the distance D from the relationship storage device 401. Further, the position specifying unit 305 calculates the value of the distance D from the magnetic field radiator 1 to the measurement target conductive film 5 based on the read relationship and the measured value of the resistance R or the measured value of the coil 11. calculate. For example, when the relationship is represented by an expression in which the distance D is a dependent variable and the resistance R is an independent variable, the position specifying unit 305 substitutes the measured value of the resistance R into the independent variable of the expression, and the distance D Is calculated. Alternatively, when the relationship is represented by an expression in which the distance D is a dependent variable and Q is an independent variable, the position specifying unit 305 substitutes the measured value of Q for the independent variable of the expression to obtain the value of the distance D Is calculated. The position specifying unit 305 causes the output device 313 to output the calculated value of the distance D, for example.

  As described above, according to the conductive film sensor according to the first embodiment, by selecting an appropriate frequency, the interval M between the conductor 4 and the conductive film 5 to be measured is unknown, and Even if it changes, the distance D from the magnetic field radiator 1 to the conductive film 5 to be measured can be accurately measured. The conductive film sensor according to the first embodiment is a metal foil used for, for example, an electrode of a battery, and is useful for measuring the position of a metal foil in which a metal roller for transportation is arranged behind. It is.

(Second Embodiment)
In the first embodiment, the sample conductive film 3 shown in FIG. 1 is made of aluminum and has a thickness of 10 μm, and the sample conductor 2 is made of aluminum and has a thickness of 10 mm. Here, the resistance value R or Q value of the coil can vary depending on the material and thickness of the sample conductive film 3 and the sample conductor 2. Therefore, the relationship stored in the relationship storage device 401 may be stored in association with the respective materials and thicknesses of the sample conductive film 3 and the sample conductor 2.

  FIG. 13 shows that the distance M between the sample conductive film 3 made of aluminum and having a thickness of 10 μm and the sample conductor 2 made of stainless steel (SUS) and having a thickness of 10 mm unlike the first embodiment is 5 μm, The distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 when the magnetic field of 50 kHz is radiated from the coil 11 to 25 μm, 50 μm, 75 μm, 100 μm, 500 μm, and 1000 μm, and the coil It is a graph which shows an example of the relationship with the measured value of 11 resistance R. FIG. 14 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  FIG. 15 shows the distance M between the sample conductive film 3 made of aluminum having a thickness of 10 μm and the sample conductor 2 made of stainless steel (SUS) having a thickness of 10 mm, which is 5 μm, 25 μm, 50 μm, 75 μm, 100 μm, 500 μm. When the magnetic field of 120 kHz is radiated from the coil 11 to 1000 μm, the distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 and the measured value of the resistance R of the coil 11 are obtained. It is a graph which shows an example of this relationship. FIG. 16 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  FIG. 17 shows an interval M between the sample conductive film 3 made of aluminum having a thickness of 10 μm and the sample conductor 2 having a thickness of 10 mm made of stainless steel (SUS) of 5 μm, 25 μm, 50 μm, 75 μm, 100 μm, and 500 μm. When the magnetic field of 300 kHz is radiated from the coil 11 to 1000 μm, the distance D between the coil 11 and the sample conductive film 3 acquired by the characteristic acquisition unit 301 and the measured value of the resistance R of the coil 11 are obtained. It is a graph which shows an example of this relationship. FIG. 18 is a graph showing an example of the relationship between the distance D between the coil 11 and the sample conductive film 3 and the measured value of Q of the coil 11 acquired by the characteristic acquisition unit 301 under the same conditions. is there.

  FIG. 19 shows that when the sample conductor 2 is made of stainless steel (SUS), the distance D from the magnetic field radiator 1 to the sample conductive film 3 is 2 mm, and the distance M between the sample conductor 2 and the sample conductive film 3 is set. It is a graph which shows an example of the variation | change_quantity of Q value when changing. As shown in FIG. 19, when the frequency of the magnetic field is 120 kHz, the amount of change in the Q value is the smallest. As described above, the frequency of the magnetic field at which the amount of change in the Q value is minimized can vary depending on the material and thickness of the sample conductive film 3 and the sample conductor 2.

  20 to 22 are graphs when the inductance L of the coil 11 is measured under the same conditions as those for creating the graphs of FIGS. 13 to 19. As shown in FIGS. 20 to 22, the inductance L of the coil 11 is affected by the change in the interval M even when the sample conductor 2 is made of stainless steel (SUS).

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, embodiments, and operation techniques should be apparent to those skilled in the art. For example, in the first embodiment, the example in which the magnetic field radiator 1 has one coil 11 has been shown. However, as shown in FIG. 112 and a third coil 113 may be included. In this case, the first coil 111 emits a first magnetic field, the second coil 112 emits a second magnetic field, and the third coil 113 emits a third magnetic field. The first coil 111, the second coil 112, and the third coil 113 are arranged in parallel so that the distance D from the sample conductive film 3 is the same. The first coil 111, the second coil 112, and the third coil 113 are separated from each other so that interference between the first magnetic field, the second magnetic field, and the third magnetic field is reduced. May be arranged. Alternatively, the first coil 111, the second coil 112, and the third coil 113 may alternately generate a magnetic field every predetermined time or every predetermined wave number. Thus, it should be understood that the present invention includes various embodiments and the like not described herein.

DESCRIPTION OF SYMBOLS 1 Magnetic field radiator 2 Sample conductor 3 Sample conductive film 4 Conductor 5 Measuring object conductive film 11, 111, 112, 113 Coil 301 Characteristic acquisition part 302 Frequency specification part 303 Relationship acquisition part 304 Measurement part 305 Position specification part 313 Output device 401 relation storage device

Claims (9)

Placing a magnetic field emitter toward the sample conductive film with the sample conductor behind it;
While changing the distance between the sample conductive film and the sample conductor, a plurality of magnetic fields having different frequencies are radiated from the magnetic field radiator toward the sample conductive film, and the resistance or quality factor of the magnetic field radiator Measuring and
Identifying the frequency of the magnetic field with the least variation in resistance or quality factor when changing the spacing;
Obtaining a relationship between the position of the sample conductive film and the resistance or quality factor when the magnetic field of the specified frequency is irradiated toward the sample conductive film;
Disposing the magnetic field radiator toward a measurement target conductive film having a conductor disposed behind;
Radiating a magnetic field of the specified frequency toward the conductive film to be measured, and measuring the resistance or quality factor of the magnetic field radiator;
Based on the relationship and the measured value of the resistance or quality factor when the magnetic field is radiated toward the measurement target conductive film, specifying the position of the measurement target conductive film;
A method for detecting a conductive film, comprising: The sample conductor and the conductor are made of the same material,
The sample conductive film and the measurement target conductive film are made of the same material.
The method for detecting a conductive film according to claim 1.   The method for detecting a conductive film according to claim 1 or 2, wherein the thickness of the sample conductive film and the thickness of the measurement target conductive film are the same.   The method for detecting a conductive film according to claim 1, wherein the thickness of the sample conductor and the thickness of the conductor are thicker than a skin depth with respect to the specified frequency. A magnetic field radiator that emits a plurality of magnetic fields each having a different frequency;
The magnetic field when the plurality of magnetic fields are radiated from the magnetic field emitter while changing the distance between the sample conductive film and the sample conductor toward the sample conductive film on which the sample conductor is disposed behind. A characteristic acquisition unit for acquiring the resistance or quality factor of the radiator;
A frequency specifying unit that specifies the frequency of the magnetic field with the least variation in resistance or quality factor when the interval is changed;
A relationship acquisition unit for acquiring a relationship between the position of the sample conductive film and the resistance or quality factor when the magnetic field of the specified frequency is irradiated toward the sample conductive film;
A measurement unit that radiates a magnetic field of the specified frequency from the magnetic field radiator toward a measurement target conductive film having a conductor disposed behind, and measures a resistance or a quality factor of the magnetic field radiator;
Based on the relationship and the measured value of the resistance or quality factor when the magnetic field is emitted toward the measurement target conductive film, a position specifying unit that specifies the position of the measurement target conductive film,
A conductive film sensor. The sample conductor and the conductor are made of the same material,
The sample conductive film and the measurement target conductive film are made of the same material.
The conductive film sensor according to claim 5.   The conductive film sensor according to claim 5 or 6, wherein a thickness of the sample conductive film and a thickness of the measurement target conductive film are the same.   The conductive film sensor according to claim 5, wherein the thickness of the sample conductor and the thickness of the conductor are thicker than a skin depth with respect to the specified frequency. Placing a magnetic field emitter toward the sample conductive film with the sample conductor behind it;
While changing the distance between the sample conductive film and the sample conductor, a plurality of magnetic fields having different frequencies are radiated from the magnetic field radiator toward the sample conductive film, and the resistance or quality factor of the magnetic field radiator Measuring and
Identifying the frequency of the magnetic field with the least variation in resistance or quality factor when changing the spacing;
A method for setting a magnetic field frequency of a conductive film sensor.