JP5727312B2 - Conductor sensor and conductor detection method - Google Patents

Description

  The present invention relates to a detection technique, and relates to a conductor sensor and a conductor detection method.

  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, an object of the present invention is to provide a conductor sensor and a conductor detection method capable of specifying the positions of at least two conductors.

  According to an aspect of the present invention, (a) a magnetic field radiator that radiates first and second magnetic fields having different frequencies, and (b) a first conductor and a first conductor are disposed in front of the first conductor. The first relationship between the characteristics of the magnetic field emitter, the positions of the first and second electric conductors, and the first and second when the first electric field is irradiated to the second electric conductor using the magnetic field radiator A relationship storage device for storing the characteristics of the magnetic field radiator and the second relationship between the positions of the first and second conductors when the second magnetic field is irradiated to the second conductor using the magnetic field radiator; (C) the characteristics of the magnetic field radiator and the first characteristic when the first magnetic field is irradiated to the first measuring object conductor and the second measuring object conductor disposed in front of the first measuring object conductor; Based on the relationship of 1, the third relationship of the positions of the first and second conductors is calculated, and the second magnetic field is irradiated to the first and second conductors to be measured. A relationship calculation unit for calculating a fourth relationship between the positions of the first and second conductors based on the characteristics of the magnetic field radiator and the second relationship, and (d) the third relationship and the fourth relationship. And a specifying unit that specifies a combination of positions of the first and second conductors common to each other.

  According to the aspect of the present invention, (a) the first conductor and the second conductor disposed in front of the first conductor are irradiated with the first magnetic field using the magnetic field radiator. Providing a first relationship between the characteristics of the magnetic field radiator and the positions of the first and second conductors, and (b) using a magnetic field radiator for the first and second conductors. Preparing a second relationship between the characteristics of the magnetic field radiator and the positions of the first and second conductors when a second magnetic field having a frequency different from that of the magnetic field is irradiated, and (c) a first Based on the characteristics and the first relationship of the magnetic field emitter when the first magnetic field is irradiated to the measurement target conductor and the second measurement target conductor disposed in front of the first measurement target conductor, Calculating the third relationship between the positions of the first and second conductors, and (d) irradiating the first and second measurement target conductors with the second magnetic field. Calculating the fourth relationship of the positions of the first and second conductors based on the characteristics of the magnetic field radiator and the second relationship; and (e) common to the third relationship and the fourth relationship. Identifying a combination of positions of the first and second conductors. A method of detecting a conductor is provided.

  According to the present invention, it is possible to provide a conductor sensor and a conductor detection method capable of specifying the positions of at least two conductors.

It is a schematic diagram of the conductor sensor which concerns on embodiment of this invention. It is a graph which shows the 1st relationship of the Q value of the 1st coil at the time of irradiating the 1st magnetic field concerning an embodiment of the invention, and the position of the 1st and 2nd electric conductor. It is a graph which shows the 2nd relationship of the Q value of the 2nd coil at the time of irradiating the 2nd magnetic field concerning an embodiment of the invention, and the position of the 1st and 2nd electric conductor. 1st and 2nd electric conduction based on Q value and the 1st relation of the 1st coil at the time of irradiating 1st magnetic field to the 1st and 2nd measuring object electric conductor concerning an embodiment of the invention It is a graph which shows the 3rd relationship of the position of a body. First and second conductivity based on the Q value of the second coil and the second relationship when the first and second measurement target conductors according to the embodiment of the present invention are irradiated with the second magnetic field. It is a graph which shows the 4th relationship of the position of a body. It is the graph which superimposed the 3rd relationship and 4th relationship which concern on embodiment of this invention. It is a schematic diagram of the conductor 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.

  As shown in FIG. 1, the conductor sensor according to the embodiment has a first coil 11 that radiates a first magnetic field having a first frequency, and a second frequency that is different from the first frequency. The magnetic field radiator 1 which has the 2nd coil 12 which radiates | emits a 2nd magnetic field, and the central processing unit (CPU) 300 connected to the magnetic field radiator 1 are provided. The conductor sensor according to the embodiment further includes a relation storage device 401 connected to the CPU 300. The relationship storage device 401 was acquired in advance by irradiating the first conductor and the second conductor disposed in front of the first conductor with the first magnetic field using the magnetic field emitter 1. The first relationship between the characteristics of the magnetic field radiator 1 and the positions of the first and second conductors is preserved. The relation storage device 401 is acquired in advance by irradiating the first conductor and the second conductor disposed in front of the first conductor with the second magnetic field using the magnetic field emitter 1. Further, the second relationship between the characteristics of the magnetic field radiator 1 and the positions of the first and second conductors is also preserved.

  The CPU 300 includes a relationship calculation unit 301. The relationship calculating unit 301 irradiates the first measurement target conductor 2 and the second measurement target conductor 3 disposed in front of the first measurement target conductor 2 from the magnetic field radiator 1 with the first magnetic field. And the third position of the first conductor and the position of the second conductor based on the characteristics of the magnetic field radiator 1 and the first relation stored in the relation storage device 401. Is calculated. In addition, the relationship calculation unit 301 stores the relationship between the characteristics of the magnetic field radiator 1 when the second magnetic field is irradiated from the magnetic field radiator 1 to the first measurement target conductor 2 and the second measurement target conductor 3, and the relationship memory. Based on the second relationship stored in the device 401, a fourth relationship between the position of the first conductor and the position of the second conductor is also calculated. Further, the CPU 300 includes a specifying unit 303 that specifies a combination of the position of the first conductor and the position of the second conductor, which is common to the third relationship and the fourth relationship.

  The position of the specified first conductor is the position of the first measurement target conductor 2. The position of the first measurement target conductor 2 is, for example, the relative position of the first measurement target conductor 2 with respect to the magnetic field radiator 1, and more specifically, the distance D from the magnetic field radiator 1. . Further, the position of the specified second conductor is the position of the second conductor 3 to be measured. The position of the second measurement target conductor 3 is, for example, the relative position of the second measurement target conductor 3 with respect to the first measurement target conductor 2, and more specifically, the first measurement target conductivity. This is a distance M from the front surface of the body 2 to the back surface of the second measurement target conductor 3.

  The 1st coil 11 and the 2nd coil 12 are arranged in parallel so that distance D with the 2nd measuring object conductor 3 may become the same. The first coil 11 and the second coil 12 may be spaced apart so as to reduce interference between the first magnetic field and the second magnetic field. Further, the difference between the first frequency and the second frequency may be set so that interference is reduced. Alternatively, the first coil 11 and the second coil 12 may alternately generate a magnetic field every predetermined time or every predetermined wave number. Furthermore, when it is desired to reduce the influence of the resistivity variation of the first measurement target conductor 2 or the second measurement target conductor 3, the first measurement target conductor 2 or the second measurement target conductor 3 is used. You may set the frequency which suppresses the fluctuation | variation of resistivity. For example, when there is a variation in the film thickness of the second measurement target film 3 as an error factor, it is within a range in which the positions of the first measurement target conductor 2 and the second measurement target conductor 3 can be detected. Thus, the first and second frequencies may be lowered.

Each of the first measurement object conductor 2 and the second measurement object conductor 3 is made of, for example, a magnetic material such as iron, or a non-magnetic material such as aluminum, copper, or an alloy containing these predominantly. The first measurement target conductor 2 is a plate or the like that is thicker than the skin depth for the lower frequency of the first and second frequencies. In addition, the 1st measuring object conductor 2 may be a thin film etc. thinner than the skin depth with respect to the lower frequency among the first and second frequencies. Moreover, the 2nd measuring object conductor 3 is a thin film etc. thinner than the skin depth with respect to the lower frequency among the 1st and 2nd frequencies. The first coil 11 forms part of an LC oscillation circuit. The LC oscillation circuit is configured such that the oscillation amplitude is a monotone function of the quality factor value of the first coil 11 (hereinafter referred to as “Q value”). The Q value of the first coil 11 is given by the following equation (1), where ω is the resonance angular frequency, L is the self-inductance of the first coil 11, and R is the high-frequency resistance of the first 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 first coil 11 toward the second measurement target conductor 3 and the first measurement target conductor 2, and the second measurement target conductor 3. And an eddy current generate | occur | produces in each of the 1st conductor 2 to be measured. The loss of electrical energy due to the eddy current increases the apparent high frequency resistance R of the first coil 11 and decreases the Q value. Accordingly, the change in the Q value depends on the positions of the second measurement target conductor 3 and the first measurement target conductor 2. In addition, changes in characteristics such as apparent self-inductance, high-frequency resistance, or impedance of the first coil 11, changes in the oscillation of the LC oscillation circuit, and changes in the current flowing in the LC oscillation circuit are also related to the second. This depends on the positions of the measurement object conductor 3 and the first measurement object conductor 2. The same applies to the second coil 12.

  Here, for example, the magnetic field radiator 1 irradiates the second measuring object conductor 3 and the first measuring object conductor 2 with a first magnetic field of 100 kHz as the first frequency from the first coil 11. The measured value of the Q value of the first coil 11 is transmitted to the relationship calculation unit 301. Further, as an example, the magnetic field radiator 1 irradiates the second measurement target conductor 3 and the first measurement target conductor 2 with a second magnetic field of 500 kHz as the second frequency from the second coil 12, The measurement value of the Q value of the second coil 12 is transmitted to the relationship calculation unit 301.

  When acquiring the first relationship as shown in FIG. 2 stored in the relationship storage device 401, for example, the first conductor to be measured is substantially equal in size and material to the first conductor 2 to be measured. A second conductor having the same size and material as the second measurement target conductor 3 is prepared. Next, in each case where the distance M between the first conductor and the second conductor disposed in front of the first conductor is, for example, 25 μm, 50 μm, 75 μm, and 100 μm, FIG. A first magnetic field of 100 kHz is radiated from the first coil 11 while changing the distance D between the first coil 11 and the first conductor shown, and the Q value of the first coil 11 is measured. . Thereby, as shown in FIG. 2, the Q value of the first coil 11, the distance D between the magnetic field radiator 1 and the first conductor, the distance M between the first and second conductors, The first relationship is obtained.

  When acquiring the second relationship as shown in FIG. 3 stored in the relationship storage device 401 shown in FIG. 1, for example, a first that is substantially the same in size and material as the first measurement target conductor 2. And a second conductor having substantially the same size and material as the second measuring object conductor 3 are prepared. Next, in each case where the distance M between the first conductor and the second conductor is, for example, 25 μm, 50 μm, 75 μm, and 100 μm, the second coil 12 and the first conductor shown in FIG. A second magnetic field of 500 kHz is emitted from the second coil 12 while changing the distance D between the body and the Q value of the second coil 12 is measured. Thereby, as shown in FIG. 3, the Q value of the second coil 12, the distance D between the magnetic field radiator 1 and the first conductor, the distance M between the first and second conductors, The second relationship is obtained. Note that the first relationship and the second relationship may be input to the relationship storage device 401 from the input device 312 illustrated in FIG.

  The relationship calculation unit 301 receives the measured value of the Q value of the first coil 11 from the magnetic field radiator 1. In addition, the relationship calculation unit 301 reads the first relationship illustrated in FIG. 2 from the relationship storage device 401. When the measured value of the Q value of the first coil 11 is 51.8 when the second magnetic field to be measured 3 and the first electrical conductor to be measured 2 are irradiated with the first magnetic field of 100 kHz, The relationship calculation unit 301 calculates the distance D between the magnetic field radiator 1 and the first conductor as shown in FIG. 4 from the first relationship shown in FIG. The third relationship between the distance M between the conductors is calculated.

  Further, the relationship calculation unit 301 receives the measured value of the Q value of the second coil 12 from the magnetic field radiator 1. Further, the relationship calculation unit 301 reads the second relationship illustrated in FIG. 3 from the relationship storage device 401. The measured value of the Q value of the second coil 12 when the second magnetic field 3 and the first electric conductor 2 shown in FIG. 1 are irradiated with the second magnetic field of 500 kHz is 113.5. If there is, the relationship calculation unit 301 calculates the distance D between the magnetic field radiator 1 and the first conductor as shown in FIG. 5 from the second relationship shown in FIG. A fourth relationship between the distance M between the first and second conductors is calculated.

  As illustrated in FIG. 6, the specifying unit 303 illustrated in FIG. 1 is provided between the magnetic field radiator 1 and the first conductor at the intersection of the function that provides the third relationship and the function that provides the fourth relationship. The value of the distance D and the value of the distance M between the first and second conductors are specified. The specified value of the distance D between the magnetic field radiator 1 and the first conductor is a measured value of the distance D from the magnetic field radiator 1 to the first measurement target conductor 2 shown in FIG. Further, the value of the specified distance M between the first and second conductors becomes the measured value of the distance M between the first measurement target conductor 2 and the second measurement target conductor 3. The specifying unit 303 includes a measurement value of the distance D from the magnetic field radiator 1 to the first measurement target conductor 2 and a measurement value of the interval M between the first measurement target conductor 2 and the second measurement target conductor 3. Are output to the output device 313, for example.

  When the slope of the function giving the third relation shown in FIG. 4 and the slope of the function giving the fourth relation shown in FIG. 5 are approximated, the magnetic field radiator 1 and the first conductor are An error may occur when specifying the value of the distance D and the value of the distance M between the first and second conductors. Therefore, the first frequency of the first magnetic field and the second frequency are set so that the difference between the slope of the function that gives the third relationship and the slope of the function that gives the fourth relationship is greater than or equal to a predetermined magnitude. A second frequency of the magnetic field may be set.

  As described above, according to the conductor sensor according to the embodiment, the position of the first measurement target conductor 2 and the position of the second measurement target conductor 3 shown in FIG. 1 are simultaneously measured. It becomes possible. Furthermore, according to the conductor sensor according to the embodiment, the presence of the first measurement target conductor 2 does not give an error to the measured value of the position of the second measurement target conductor 3. Further, the presence of the second measurement target conductor 3 does not give an error to the measured value of the position of the first measurement target conductor 2. Therefore, according to the conductor sensor according to the embodiment, the position of the first measurement target conductor 2 and the position of the second measurement target conductor 3 can be measured in real time and with high accuracy. Become.

(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 embodiment, it has been described that the position of the second measurement target conductor 3 is the distance M from the surface of the first measurement target conductor 2 to the back surface of the second measurement target conductor 3. However, the position of the second measurement target conductor 3 may be a distance from the surface of the first measurement target conductor 2 to the surface of the second measurement target conductor 3. Alternatively, the position of the second measurement target conductor 3 may be represented by a distance from the magnetic field radiator 1 to the second measurement target conductor 3.

  Moreover, in embodiment, although the magnetic field radiator 1 showed the example which has the 1st coil 11 and the 2nd coil 12, as shown in FIG. Only the coil 13 may be included. In this case, the single coil 13 may radiate the first magnetic field and the second magnetic field alternately every predetermined time or every predetermined wave number. Alternatively, the single coil 13 may emit a magnetic field obtained by superimposing a first magnetic field having a first frequency and a second magnetic field having a second frequency. In this case, the characteristic such as the Q value or impedance of the single coil 13 is divided into a characteristic relating to the first frequency and a characteristic relating to the second frequency. 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 1st measuring object conductor 3 2nd measuring object conductor 11 1st coil 12 2nd coil 13 Coil 300 CPU
301 Relationship Calculation Unit 303 Identification Unit 312 Input Device 313 Output Device 401 Relationship Storage Device

Claims (14)

A magnetic field radiator that radiates first and second magnetic fields having different frequencies;
Characteristics of the magnetic field radiator when the first magnetic field is applied to the first conductor and the second conductor disposed in front of the first conductor by using the magnetic field radiator; The first relationship between the positions of the first and second conductors and the magnetic field radiator when the first and second conductors are irradiated with the second magnetic field using the magnetic field radiator. A relation storage device for storing the characteristics of the first relation and the second relation of the positions of the first and second conductors;
Characteristics of the magnetic field radiator when the first magnetic field is applied to the first measurement target conductor and the second measurement target conductor disposed in front of the first measurement target conductor, and the first Based on the relationship of 1, the third relationship between the positions of the first and second conductors is calculated, and the magnetic field when the first and second measurement target conductors are irradiated with the second magnetic field. A relationship calculating unit that calculates a fourth relationship of the positions of the first and second conductors based on a characteristic of the radiator and the second relationship;
A specifying unit for specifying a combination of positions of the first and second conductors common to the third relationship and the fourth relationship;
With
The positions of the first and second conductors are relative positions of the first and second conductors with respect to the magnetic field radiator.
Conductor sensor.   A magnetic field radiator that radiates first and second magnetic fields having different frequencies;
  Characteristics of the magnetic field radiator when the first magnetic field is applied to the first conductor and the second conductor disposed in front of the first conductor by using the magnetic field radiator; The first relationship between the positions of the first and second conductors and the magnetic field radiator when the first and second conductors are irradiated with the second magnetic field using the magnetic field radiator. A relation storage device for storing the characteristics of the first relation and the second relation of the positions of the first and second conductors;
  Characteristics of the magnetic field radiator when the first magnetic field is applied to the first measurement target conductor and the second measurement target conductor disposed in front of the first measurement target conductor, and the first Based on the relationship of 1, the third relationship between the positions of the first and second conductors is calculated, and the magnetic field when the first and second measurement target conductors are irradiated with the second magnetic field. A relationship calculating unit that calculates a fourth relationship of the positions of the first and second conductors based on a characteristic of the radiator and the second relationship;
  A specifying unit for specifying a combination of positions of the first and second conductors common to the third relationship and the fourth relationship;
  With
  The position of the first conductor is a relative position of the first conductor with respect to the magnetic field radiator;
  The position of the second conductor is a relative position of the second conductor with respect to the first conductor.
  Conductor sensor. The conductor sensor according to claim 1 or 2 , wherein the magnetic field radiator includes a first coil that radiates the first magnetic field and a second coil that radiates the second magnetic field. Wherein the magnetic field radiators, at different times, the first and the magnetic field comprises a coil for radiating a second magnetic field, the conductor sensor according to claim 1 or 2. Wherein the magnetic field radiators, the first and the magnetic field comprises a coil for radiating a second magnetic field superimposed on the first magnetic field, the conductor sensor according to claim 1 or 2. A coil of the magnetic field radiators constitutes an LC oscillator circuit, characteristics of the field emitter is the oscillation amplitude of the LC oscillator circuit, conductor sensor according to claim 1 or 2. The conductor sensor according to any one of claims 1 to 5 , wherein the characteristic of the magnetic field radiator is impedance, inductance, resistance, or quality factor. Characteristics of the magnetic field radiator when the first magnetic field is applied to the first conductive material and the second conductive material disposed in front of the first conductive material using the magnetic field radiator; Providing a first relationship between positions of the first and second conductors;
Characteristics of the magnetic field radiator when the first and second conductors are irradiated with a second magnetic field having a frequency different from that of the first magnetic field using the magnetic field radiator; Providing a second relationship of the positions of the conductors;
Characteristics of the magnetic field radiator when the first magnetic field is applied to the first measuring object conductor and the second measuring object conductor arranged in front of the first measuring object conductor, and the first Calculating a third relationship of the positions of the first and second conductors based on the relationship of 1;
Based on the characteristics of the magnetic field radiator and the second relationship when the first and second conductors to be measured are irradiated with the second magnetic field, the positions of the first and second conductors are changed. Calculating the relationship of 4;
Identifying a combination of positions of the first and second conductors common to the third relationship and the fourth relationship;
Only including,
The positions of the first and second conductors are relative positions of the first and second conductors with respect to the magnetic field radiator.
Conductor detection method.   Characteristics of the magnetic field radiator when the first magnetic field is applied to the first conductive material and the second conductive material disposed in front of the first conductive material using the magnetic field radiator; Providing a first relationship between positions of the first and second conductors;
  Characteristics of the magnetic field radiator when the first and second conductors are irradiated with a second magnetic field having a frequency different from that of the first magnetic field using the magnetic field radiator; Providing a second relationship of the positions of the conductors;
  Characteristics of the magnetic field radiator when the first magnetic field is applied to the first measuring object conductor and the second measuring object conductor arranged in front of the first measuring object conductor, and the first Calculating a third relationship of the positions of the first and second conductors based on the relationship of 1;
  Based on the characteristics of the magnetic field radiator and the second relationship when the first and second conductors to be measured are irradiated with the second magnetic field, the positions of the first and second conductors are changed. Calculating the relationship of 4;
  Identifying a combination of positions of the first and second conductors common to the third relationship and the fourth relationship;
  Including
  The position of the first conductor is a relative position of the first conductor with respect to the magnetic field radiator;
  The position of the second conductor is a relative position of the second conductor with respect to the first conductor.
  Conductor detection method. The method for detecting a conductor according to claim 8 or 9, wherein the magnetic field radiator includes a first coil that radiates the first magnetic field and a second coil that radiates the second magnetic field. . The method for detecting a conductor according to claim 8 or 9, wherein the magnetic field radiator includes a coil that radiates the first magnetic field and the second magnetic field at different times. The method for detecting a conductor according to claim 8 or 9, wherein the magnetic field radiator includes a coil that radiates the first magnetic field and the second magnetic field superimposed on the first magnetic field. The method for detecting a conductor according to claim 8 or 9, wherein the magnetic field radiator includes a coil constituting an LC oscillation circuit, and the characteristic of the magnetic field radiator is an oscillation amplitude of the LC oscillation circuit. The characteristics of the magnetic field radiators, impedance, inductance, a resistance, or quality factor, the detection method of the conductive member according to any one of claims 8 to 12.