JP2010276587A - Device, method and program for detecting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detecting device which can obtain conditions near the apex of an linear conductor even if there is no observation space near the apex thereof. <P>SOLUTION: The detecting device 100 detecting discharge conditions of liquid at the apex of a discharge needle N includes an excitation section 10 exciting standing waves of electromagnetic wave at microwave frequency in a cavity resonator 11 with TM01 mode to pass AC current I at microwave frequency to the discharge needle N arranged along the center of rotating magnetic field of the TM01 mode concerned through electromagnetic induction, a receiving section 20 receiving electromagnetic wave emitted from the discharge needle N resulting from flowing of AC current I, and a detecting section 30 detecting presence of discharge and the discharge rate at the apex of the discharge needle N based on electromagnetic wave received by the receiving section 20. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a detection device, a detection method, and a detection program, and more particularly to a detection device, a detection method, and a detection program for detecting a situation at one end of a linear conductor.

  Conventionally, in devices that discharge liquids such as chemicals and liquid adhesives for woodwork from discharge needles, a flow meter is provided in the liquid flow path, and a detection device that detects the presence or absence of discharge and the amount of discharge is provided around the discharge needles As a result, the discharge amount of the liquid is controlled based on the measurement result of these flow meters and the detection result of the detection device.

  However, when the discharge amount is controlled using a flow meter, it is not always possible to directly grasp whether or not the required amount of liquid has been injected. There is a possibility that the discharge amount varies. Therefore, if high accuracy is not required, the discharge status can be monitored indirectly with a flow meter provided in the flow path, but if it is necessary to precisely control the discharge amount, it is located near the discharge port. It was necessary to directly monitor the discharge situation by providing the detection device.

  Therefore, when precisely controlling the discharge amount, it is necessary to secure an observation space for disposing the detection device near the tip of the discharge needle, but there are cases where the observation space cannot be secured. For example, a dowel to be filled with a liquid adhesive for woodworking, a tank for storing beverages of a vending machine, and the like. In such a case, it is necessary for the operator to control the liquid injection device based on experience or to provide an injection amount inspection step after the injection. For these reasons, when the observation space could not be secured at the tip of the discharge needle, the liquid injection operation could not be completely automated.

  In the above description, the tubular discharge needle has been described as an example. However, if the situation around the discharge needle can be grasped, the situation around the tip should be grasped regardless of the presence or absence of the tube. For example, there is a possibility that the present invention can be applied to detection of an object that contacts the tip of a linear conductor, or detection of an object that approaches the tip or an object that moves away from the tip.

  The present invention has been made in view of the above-mentioned problems, and more specifically, a detection device that can grasp the state of the discharge needle tip of the liquid injection device as described above even when there is no observation space around it. In general, the object is to provide a detection device, a detection method, and a detection program that can grasp the situation near the tip of the linear conductor even if there is no observation space near the tip of the linear conductor.

  In order to solve the above problems, a detection device of the present invention is a detection device that detects a situation at one end of a linear conductor, and an excitation unit that causes an alternating current to flow through the conductor using a cavity resonator; A receiving unit that receives an electromagnetic wave radiated from the conductor when the alternating current flows; and a detection unit that detects a situation at the one end of the conductor based on the electromagnetic wave received by the receiving unit. . The situation here refers to the presence / absence of an object attached to the one end, the presence / absence of an object arranged close to the one end, or the presence / absence of an object approaching or separating from the one end. . More specifically, the conductive material adheres to the tip, or the attached conductive material is detached from the tip, or the interface that can reflect electromagnetic waves is approaching or separated from the tip. The situation is being illustrated.

  In the above configuration, the alternating current travels through the conductor to the one end and is reflected there. Further, when an alternating current flows through the conductor, electromagnetic waves are radiated from the conductor. When this radiated electromagnetic wave is received by the conductor, an alternating current is generated in the conductor. In particular, the alternating current induced by the electromagnetic wave incident from the side that coincides with the length direction of the conductor is the length of the conductor. It will travel in the direction and flow through the entire conductor.

  At this time, if the conductor is grounded in any part on the other end side than the part where the excitation unit induces the alternating current using the cavity resonator, the alternating current is generated on the other end side. Since it does not reflect, it becomes easy to isolate | separate components, such as the alternating current reflected by the said one end side, and the alternating current induced by the incident electromagnetic wave.

  That is, the detection unit is caused by the component radiated due to the alternating current reflected at the one end or the alternating current generated due to the electromagnetic wave received at the one end in the electromagnetic wave received by the receiving unit. The amount that varies depending on the component emitted is detected. Based on the detected fluctuation amount, the situation at the one end is detected. That is, the detection unit determines whether or not an object that generates an electromagnetic interaction with the tip of the conductor exists in the vicinity of the tip of the conductor.

By the way, as an alternative aspect of the present invention for efficiently flowing an alternating current to the conductor by the cavity resonator, the excitation unit applies a TM01 mode standing wave of a predetermined frequency to the cavity resonator. When excited, the conductor may be disposed along the center of the rotating magnetic field of the TM01 mode.
In the TM01 mode, an electric field is concentrated at the center of the rotating magnetic field, and the electric field vector at the center of the rotating magnetic field is determined in one direction. That is, if the linear conductor is arranged along the center of the rotating magnetic field, the total sum of the electric field vectors passing through the conductor is maximized, so that the standing wave of the cavity resonator is changed to the alternating current flowing through the conductor. Conversion efficiency is maximized.

Further, as an optional aspect of the present invention for enhancing the influence of the one end state on the alternating current, the excitation unit excites a standing wave in a microwave frequency band in the cavity resonator, thereby You may make it let the alternating current of a microwave frequency flow through a conductor.
The alternating current of microwave frequency becomes a skin current in the conductor. When the AC current becomes a skin current, most of the current flows from the outer edge of the conductor to the skin thickness, so that the interaction between the AC current and the outside is maximized. That is, the influence of the situation at the one end becomes more prominent in the alternating current.

Further, as an optional aspect of the present invention for improving the detection accuracy of the state of the one end, the alternating current flowing through the conductor is a standing wave, and the tip of the conductor is the standing wave. The length may substantially match the stomach.
When the length of the ejection needle N is adjusted so that the position of the antinode of the standing wave substantially coincides with the tip of the conductor, the intensity of the reflected wave R1 in a state where no object is attached to the tip of the conductor. Is maximized. When an object adheres to the tip of the conductor, the reflection position of the excitation wave G shifts or the reflection intensity changes, so that the intensity of the standing wave varies.

As a selective one aspect of the present invention for detecting a situation in which the liquid is discharged from the tip of the linear conductor when the linear conductor is tubular and the liquid passes through the inside thereof, The conductor is a tube, and the detection unit determines the timing at which liquid discharge starts from the one end through the tube and the timing at which liquid discharge ends based on the electromagnetic wave received by the reception unit. You may comprise so that it may detect.
According to this configuration, when liquid is discharged from the tip of the conductor through the tube, the liquid adheres to the tip. Then, since the intensity of the electromagnetic wave received by the receiving unit changes, it is possible to detect the discharge state of the liquid based on this change. Further, since the intensity of the electromagnetic wave received by the receiving unit also changes when the liquid adhering to the tip of the conductor is detached from the tip, it is possible to detect the state of separation of the liquid based on this change.

  Furthermore, when the linear conductor is tubular and liquid passes through the inside, the detection unit receives the amount of liquid discharged from the one end through the tube by the reception unit. It can also be detected based on electromagnetic waves. That is, when the liquid leaves, electromagnetic waves radiated from the tip based on the alternating current are reflected from the liquid surface and returned to the tip. This electromagnetic wave is received again at the tip, and an alternating current (received wave) is generated in the conductor. In addition, an alternating current (reflected wave) in which the alternating current induced by the excitation unit is reflected at the boundary between the gas phase and the leading edge also flows at the tip. The received wave has a Doppler shift corresponding to the flying speed of the liquid, and the frequency is slightly lower than that of the reflected wave. Therefore, a Doppler beat occurs due to the superposition of the received wave and the reflected wave. If the Doppler beat frequency is measured, the flying speed of the liquid can be obtained. This flying speed is a separation speed of the liquid from the tip, and can be regarded as a discharge speed of the liquid. Therefore, the discharge amount can be obtained by multiplying the discharge speed by the cross-sectional area of the tube and the time during which the discharge is continued.

  Note that in order to measure the Doppler beat, the Doppler beat vibration must continue for a predetermined time in which the frequency of the Doppler beat can be specified in the electromagnetic wave received by the receiver. That is, the Doppler beat frequency cannot be specified unless the droplet continues to fly for the predetermined time. Of course, it is sufficient that a space that allows the droplet to fly for a period of one period of roaring is ensured at the tip of the tip, but if only a space shorter than this can be ensured, a half period or 1 / The frequency of the beat is estimated from the beat of four periods. Of course, the beat frequency may be estimated by performing sinusoidal mapping or the like on the data acquired by the detection unit.

Even if the conductor is not tubular, when an object approaches the tip of the conductor, Doppler beats occur in the electromagnetic wave, and when the object moves away from the tip of the conductor, Doppler is also applied to the electromagnetic wave. A roar occurs. Therefore, the detection unit may detect the amount of displacement between the one end and the object based on the electromagnetic wave received by the reception unit. That is, the distance between the object and the detection device can be measured.
Further, since the alternating current fluctuates not only according to the Doppler beat, but also depending on the distance between the object and the tip, if the fluctuation is calibrated as a function of the distance between the object and the tip, the object and the detection are detected. The distance to the apparatus can be measured, and the displacement amount and displacement history of the object can be acquired.

  The above-described detection device includes various modes such as being implemented in a state of being incorporated in another device or implemented together with another method. The present invention also provides a detection system including the detection device, a detection method having a process corresponding to the configuration of the above-described device, a detection program for causing a computer to realize a function corresponding to the configuration of the above-described device, and a computer recording the program It can also be realized as a readable recording medium. The inventions of these detection system, detection method, detection program, and medium on which the program is recorded also have the above-described operations and effects. Of course, configurations described in claims 2 to 9 are also applicable to the system, the method, the program, and the recording medium.

As described above, according to the present invention, it is possible to provide a detection device that can grasp the situation in the vicinity of the tip of the linear conductor even when there is no observation space in the vicinity of the tip.
Moreover, according to the invention concerning Claim 2, detection sensitivity can be improved.
According to the invention of claim 3, since the conversion efficiency into alternating current can be improved, the detection sensitivity is improved.
Moreover, according to the invention concerning Claim 4, detection sensitivity improves.
Moreover, according to the invention concerning Claim 5, detection sensitivity improves.
According to the sixth aspect of the present invention, even when there is no observation space near the tip of the linear conductor, it is possible to know the discharge state of the liquid discharged from the tip.
According to the seventh and eighth aspects of the present invention, even when there is no observation space near the front end of the linear conductor, the discharge amount of the liquid discharged from the front end can be known.
According to the ninth aspect of the invention, it is possible to provide a micro displacement meter using electromagnetic waves, particularly microwaves, and it is possible to provide a microwave proximity switch using the same.
According to the tenth aspect of the present invention, it is possible to provide a detection method capable of grasping the situation near the tip of the linear conductor even if there is no observation space near the tip of the linear conductor.
According to the eleventh aspect of the present invention, it is possible to provide a control program for controlling the detection device that can grasp the situation near the tip of the linear conductor even if there is no observation space near the tip of the linear conductor.

It is a block diagram which shows the structure concerning one Embodiment of this invention. It is a figure explaining the skin current of an electric wire. It is a figure which shows the electromagnetic field distribution in a cavity resonator. It is a perspective view which shows the structure of a cavity resonator. It is an example of a structure for exciting the TM01 mode. It is a block diagram which shows the hardware constitutions of a receiving part and a detection part. It is the figure put together with the relationship between the electric current and electromagnetic waves in the front-end | tip of a discharge needle. FIG. 5 is a diagram showing a positional relationship between a standing wave generated by an excitation wave G and a reflected wave R1 and a discharge needle N. It is the figure which showed intensity distribution of the electromagnetic waves radiated | emitted from a discharge needle. It is the graph which measured the frequency distribution of the electromagnetic wave in each state shown in FIG. It is a graph of the intensity | strength change of the electromagnetic waves observed by the droplet being ejected and detached. It is a flowchart of a detection process. It is a block diagram which shows the structural example of a detection apparatus. It is a block diagram which shows the structural example of a detection apparatus. It is a block diagram which shows the structure of the detection apparatus concerning the modification 1. It is a block diagram which shows the structure of the detection apparatus concerning the modification 2. It is a distribution map of the electric field in the fine wire of the stainless steel bent by R10mm. It is the figure which showed an example of the electric current which generate | occur | produces at the discharge needle tip concerning the modification 3. It is a block diagram which shows the structure of the receiving part concerning the modification 4.

Hereinafter, embodiments of the present invention will be described in the following order.
(1) Configuration of the present embodiment:
(2) Detection of droplets adhering to the conductor tip:
(3) Calculation of droplet discharge amount using Doppler beat:
(4) Detection process:
(5) Miniaturization of equipment:
(6) Modification 1:
(7) Modification 2:
(8) Modification 3:
(9) Modification 4:
(10) Summary:

(1) Configuration of the present embodiment:
<Outline configuration>
FIG. 1 is a block diagram showing a configuration according to an embodiment of the present invention. As shown in the figure, the detection apparatus 100 includes an excitation unit 10 that generates a skin current by flowing an alternating current I having a predetermined frequency through a linear conductor C, and a predetermined frequency that is radiated from the conductor C by the alternating current I. A receiving unit 20 that receives electromagnetic waves and a detection unit 30 that analyzes the electromagnetic waves received by the receiving unit 20 and detects the state of the tip of the conductor C are provided. The conductor C is in contact with the excitation unit 10 on the base side, but the conductor C is not in contact with the excitation unit 10 except for the base side. That is, the conductor C is grounded only on the base side, and current is not reflected on the base side.

<AC current component>
As will be described in detail later with reference to FIG. 7, the AC current I includes not only the component directly induced by the excitation unit 10 (hereinafter referred to as “excitation wave G”), but also this excitation wave. G is a component reflected by the tip of the conductor C (hereinafter referred to as “reflected wave R1”), or a component (hereinafter, referred to as “reflected wave R1”) where an electromagnetic wave once radiated from the tip is reflected by the object surface and received again by the tip. , “Received wave R2”) and a beat component generated by mixing these components. In particular, the beat generated by the reflected wave R1 and the received wave R2 will be described as “beat DB” in the following description.
Hereinafter, each part 10-30 is demonstrated in detail.

<Excitation unit>
The excitation unit 10 generates an excitation wave G, which is an alternating current having a predetermined frequency, on the conductor C. In the present embodiment, the microwave band frequency will be described as an example of the predetermined frequency, but other frequency bands may be adopted as long as the alternating current is a frequency at which it becomes a skin current.
As shown in FIG. 2, the alternating current is converted into a skin current, so that the current is concentrated from the conductor surface to a depth of δ. However, when the conductor C is a tubular discharge needle N and is a type that allows liquid to pass inside as in the present embodiment, it is better to adopt a frequency band that converts to a skin current. It does not necessarily have to be an electromagnetic wave in a frequency band that causes a skin current.

<Relationship between conductor tip state and radiated electromagnetic wave>
The state of the tip of the conductor C detected by the detection unit 30 includes, for example, the presence / absence of liquid adhesion, the amount of liquid attached, the presence / absence of an object approaching the conductor tip, and the presence / absence of an object separated from the conductor tip. . The conductor C generates a reflected wave R1 and a received wave R2 corresponding to these states. Thus, when the alternating current flowing through the conductor C is changed by being affected by the state of the tip of the conductor C, the electromagnetic wave radiated from the conductor C also changes. That is, if the electromagnetic wave radiated from the conductor C is analyzed, the situation near the tip of the conductor C can be grasped.

<Exciting current without contact by cavity resonator>
When the alternating current I is caused to flow through the conductor C by the excitation unit 10, it is preferable to perform the contactlessly. This is because, in this embodiment, it is desired to pass an alternating current through the conductor C in a state where the root side is grounded but the tip side is electrically opened. Moreover, if it is non-contact, a connector etc. are unnecessary, and attachment / detachment of the detection apparatus 100 with respect to a test object becomes easy, and also there exists an advantage that a conductor etc. are hard to be damaged at the time of attachment or removal. In order to allow an AC current to flow through the conductor C in a non-contact manner, the excitation unit 10 includes a cavity resonator 11. The cavity resonator 11 can excite a standing wave having a specific microwave frequency inside.

  The conductor C receives a standing wave excited by the cavity resonator 11 because a part of the conductor C passes through the cavity resonator 11. At this time, if the sum of the electric field vectors passing through the conductor C has a component in the length direction of the conductor C, an alternating current corresponding to the excitation wave G is generated in the conductor C by electromagnetic induction. That is, the standing wave excited by the cavity resonator 11 is converted into an alternating current flowing through the conductor C. In the present embodiment, the standing wave excited in the cavity resonator 11 is set as the TM01 mode in order to increase the conversion efficiency for changing the standing wave into an alternating current.

<TM mode>
FIG. 3 is a diagram showing an electromagnetic field distribution in the cavity resonator 11 in which the standing wave of the TM01 mode is generated. In the figure, the electric field vector is indicated by a solid line, and the magnetic field vector is indicated by a broken line.
As shown in FIG. 3, the cavity resonator 11 generates a rotating magnetic field around the axis of the cylinder by exciting the standing wave of the TM01 mode, and has a vector in the axial direction of the cylinder. An electric field is generated. The conductor C is disposed along the axis of the cylinder that is the center of the rotating magnetic field in the TM01 mode. Therefore, in this embodiment, the conversion efficiency from the microwave to the alternating current is further improved while using the cavity resonator 11 with low radiation loss and high energy efficiency.

<Configuration of cavity resonator>
Here, an example of the structure of the cavity resonator 11 will be described with reference to FIG. Although FIG. 4 shows a cylindrical cavity resonator as an example, it is of course possible to use a rectangular cavity resonator or a spherical cavity resonator.
The cavity resonator 11 shown in FIG. 4 includes a cylindrical cylindrical side wall 11a and end side walls 11b and 11c that close both ends in the axial direction. The end side wall 11b electromagnetically seals one end of the cylindrical side wall 11a. One end of the conductor C is grounded to the end side wall 11b. The end side wall 11c is formed with an opening 11c1 at a central portion on the cylinder axis, and the other end of the cylindrical side wall 11a is electromagnetically sealed except for the opening 11c1.
The distance L between the end side wall 11b and the end side wall 11c is L = n × λ / 2 (n is a natural number) where λ is the wavelength of the standing wave of the microwave to be generated in the cavity resonator 11. ) Is satisfied.

<Excitation method>
Microwaves are introduced from the microwave unit 12 to the cavity resonator 11 configured as shown in FIG. 4 through a predetermined transmission line. As the predetermined transmission line, a coaxial line, a strip line, a waveguide, a dielectric waveguide, or the like can be used. Further, in order to couple a predetermined transmission line to the cavity resonator 11, loop coupling, probe coupling, hole coupling, slit coupling, or the like can be used. In the present embodiment, as shown in FIG. 4, a microwave is excited in the cavity resonator by inserting a loop antenna into the cavity resonator 11 and exciting a rotating magnetic field in the cavity resonator 11.
In addition, for example, even if the TE01 mode excited in the rectangular waveguide is introduced into the cylindrical resonant cavity by joining the rectangular waveguide and the cylindrical resonant cavity as shown in FIG. 5, the TM01 mode standing wave is introduced into the cylindrical resonant cavity. Can be excited.

<Frequency band to be used>
The microwave excited in the cavity resonator 11 of the present embodiment is preferably an ISM band (Industry-Science-Medical Band) microwave. This is because the ISM band has little influence on existing communications, and the regulations on electromagnetic interference (Electro Magnetic Interference) and the like are relatively loose. More specifically, the 2.4 GHz band (2400-2500 MHz), the 5.8 GHz band (5725-5875 MHz), and the 10.8 GHz band defined by the ITU (International Telecommunication Union) in the microwave band. It is preferable to use a 24 GHz band (24-24.25 GHz).

<Microwave radiated from conductor C>
As described above, since the conductor C passes through the center of the TM01 mode rotating magnetic field, an alternating current traveling in the length direction is induced. That is, the excitation wave G induced in the conductor C travels in the length direction of the conductor C and flows also to a portion outside the cavity resonator 11. The excitation wave G that has flowed to the grounded side of the conductor C (hereinafter referred to as “root side”) is diffused to the ground as it is.

  On the other hand, as described above, the excitation wave G that has flowed to the side of the conductor C that is not grounded (hereinafter referred to as the “tip side”) is reflected at the boundary surface of the tip to generate a reflected wave R1. In addition, the electromagnetic wave radiated from the tip of the conductor C has a component that returns to the tip when reflected by the surface of the object further ahead of the tip, and when this reflected electromagnetic wave component is incident from the tip. A reception wave R2 is generated. Therefore, the electromagnetic wave radiated from the conductor C is based on the alternating current of the superposition of the excitation wave G, the reflected wave R1, and the received wave R2.

<Receiver>
The receiving unit 20 receives an electromagnetic wave radiated by an alternating current flowing through the conductor C. In the present embodiment, the antenna 21 of the receiving unit 20 is arranged inside the cavity resonator 11 in order to reduce the device size, but the receiving unit 20 and the antenna 21 are outside the cavity resonator 11. You may arrange in. Moreover, although the antenna 21 of this embodiment shares the antenna which excites the standing wave in the cavity resonator 11, of course, you may arrange | position the antenna 21 prepared separately in the cavity resonator 11. FIG. .

  FIG. 6 is a block diagram illustrating a hardware configuration of the receiving unit 20 and the detecting unit 30 in the present embodiment. As shown in the figure, the receiving unit 20 includes an antenna 21, a BPF (Band Pass Filter) 22, an amplifier 23, and a detector 24. The microwave received by the antenna 21 is input to the BPF 22, and unnecessary frequency components and noise components other than the desired microwave frequency band are removed before being input to the amplifier 23. The amplifier 23 amplifies the microwave with a predetermined amplification factor. The detector 24 detects an electromagnetic wave having a predetermined frequency from the amplified microwave. The microwave detected by the detector 24 is input to the detection unit 30.

<Detector>
As shown in FIG. 6, the detection unit 30 includes an A / D converter 31 and a control unit 32. The microwave signal input from the receiving unit 20 is input to the A / D converter 31 and converted into a digital signal. The digitized microwave signal is input to the control unit 32 and processed analytically. The control unit 32 includes a ROM (Read Only Memory) in which a detection program is stored, a CPU (Central Processing Unit) that appropriately reads and executes the detection program from the ROM, and a RAM (Random Access Memory) that is used as a work area of the CPU. ). When the detection program is executed by the control unit 32, a detection process described later is executed.

(2) Detection of droplets adhering to the conductor tip:
<Droplet adhesion detection>
As a specific example of detection performed using the detection apparatus 100 described above, there is discharge detection of a dispenser. A dispenser is a so-called liquid dispensing apparatus, and is a general term for a controller that supplies a liquid in a precise amount and its peripheral devices. In this detection apparatus 100, the discharge needle N attached to the tip when supplying the liquid supplied from the dispenser is the conductor C of the present invention, and the discharge needle N is based on the intensity change of the electromagnetic wave radiated from the discharge needle N. It is detected whether or not the liquid is being discharged from the tip.

<Dispenser configuration>
As shown in FIG. 1, the discharge needle N of the dispenser is disposed along the center of the rotating magnetic field in the cavity resonator 11 and penetrates the cavity resonator 11 from side to side. Since the base side of the discharge needle N is in contact with the end side wall 11b of the cavity resonator 11, it is in a grounded state. On the other hand, the tip side protrudes outside from the opening 11c1 of the end side wall 11c without contacting the cavity resonator 11.

The base side of the discharge needle N is connected to the main body of the dispenser via a liquid supply tube or the like, and liquid is fed from the main body of the dispenser. The amount of liquid to be fed can be controlled to a certain degree of accuracy by the dispenser. For example, the feeding speed of the liquid fed to the discharge needle N can be controlled to a certain degree.
The discharge needle N is supplied with an alternating current as a mixed wave of the excitation wave G, the reflected wave R1, and the reception wave R2. FIG. 7 is a diagram summarizing the relationship between the current at the tip of the ejection needle N and the electromagnetic wave.

<Current flowing through discharge needle N>
As shown in FIG. 7, the received wave R2 is assumed to be a current generated by receiving an electromagnetic wave that is ejected from the tip of the ejection needle N and reflected from the surface of the droplet that moves away from the tip. The reflected wave R1 indicates the current reflected at the boundary between the tip of the discharge needle N and the liquid when the liquid is discharged from the tip of the discharge needle N and is attached to the tip. In the state where no liquid is attached to the surface, the current reflected at the boundary between the tip of the ejection needle N and the gas phase is indicated. In order for the reflected wave R1 generated in this way to reflect the situation near the tip of the discharge needle N more remarkably, it is preferable that the tip of the discharge needle N becomes an antinode of the standing wave.

FIG. 8 is a diagram showing the positional relationship between the standing wave generated by the excitation wave G and the reflected wave R1 and the ejection needle N. As shown in FIG. The standing wave shown in the figure is generated by the alternating current I in a state where no liquid adheres to the tip of the discharge needle N. When the length of the discharge needle N is adjusted so that the position of the antinode of the standing wave substantially coincides with the tip of the discharge needle N in this state, the reflected wave in a state where no liquid adheres to the tip of the discharge needle N. The intensity of R1 is maximized. On the other hand, when a droplet adheres to the tip of the ejection needle N, the reflection position of the excitation wave G shifts, and the intensity of the standing wave due to the superposition of the excitation wave G and the reflection wave R1 decreases. That is, if the configuration of FIG. 8 is used to detect this reduced amount, the S / N is improved.
FIG. 9 shows the intensity distribution of electromagnetic waves radiated from the ejection needle by these alternating currents, and FIG. 10 shows the measurement results.

<Electromagnetic wave radiated from discharge needle N>
FIG. 9 shows the intensity distribution of the electromagnetic wave radiated from the ejection needle, with a water droplet attached to the tip of the ejection needle N (upper figure) and with no adhesion (lower figure). As can be seen from the electric field distribution in the figure, when a water droplet adheres to the tip of the discharge needle N, the electric field around the discharge needle N becomes stronger. This indicates that when a water droplet adheres to the tip of the ejection needle N, the reflected wave R1 becomes stronger. This is because the current reflectivity at the boundary between the metal and the liquid such as water is higher than the current reflectivity at the metal / gas phase boundary.

FIG. 10 is a graph obtained by measuring the frequency distribution of the electromagnetic wave in each state shown in FIG. The figure shows the result of measuring the electromagnetic wave intensity at each frequency while sweeping the electromagnetic wave from 0 to 30 GHz with a network analyzer. The discharge needle used in the measurement of FIG. 10 is No. 13 needle (outer diameter is 2.4 mm) used for rough applications such as application of liquid adhesive for woodworking, and belongs to the largest category in the standard rank. .
In the graph of FIG. 10, it can be seen that the radiation intensity of the electromagnetic wave in each state of FIG. 9 is increased by 4 dB when the water droplet is attached. That is, it can be seen that it is possible to easily identify whether or not a water droplet is attached to the tip of the ejection needle N based on the intensity of the electromagnetic wave.

<Discharge amount detection>
Furthermore, if the detection apparatus 100 is used, it is possible not only to detect whether or not the liquid is discharged from the discharge needle N but also to grasp the discharge amount.
As described above, the timing t1 at which ejection starts and the timing t2 at which ejection ends can be detected based on changes in the intensity of electromagnetic waves. Further, the discharge amount ΔD per unit time can be roughly known from the liquid delivery speed on the dispenser side. Therefore, the total discharge amount of the discharge needle N is obtained by the calculation of ΔD × τ (τ = t2−t1).

  As described above, conventionally, in order to determine whether or not the liquid is being ejected from the ejection needle N, it has been necessary to arrange detection means such as an optical sensor near the tip of the ejection needle N. If the detection apparatus 100 according to the present embodiment is used, it is possible to identify whether or not the liquid is being discharged from the discharge needle N even if there is no observation space around the tip (discharge port) of the discharge needle, and the liquid discharge amount can be determined. It can be detected. Therefore, it is possible to know whether or not the liquid adhesive for woodworking was actually discharged even in a part where the observation space such as the back of a deep dowel is not secured, and how much liquid adhesive for woodworking is discharged. It can be ascertained.

(3) Calculation of droplet discharge amount using Doppler beat:
In addition, when the above-mentioned liquid delivery speed on the dispenser side cannot be obtained, it is also possible to calculate the liquid release speed based on the Doppler beat. In this calculation, two assumptions are made. One is that the speed at which the droplets are ejected is constant, and the other is that the separation speed is the speed during ejection.

  As shown in FIG. 8, when the liquid droplets are separated from the tip of the discharge needle N, they move away from the discharge needle N at a speed U. At this time, the component radiated in the direction of the detached droplet in the electromagnetic wave radiated from the tip of the ejection needle N is reflected toward the ejection needle N when it reaches the surface of the droplet. Since the electromagnetic wave reflected from the droplet is received again from the tip of the ejection needle, a reception wave R2 is generated in the ejection needle N by this electromagnetic wave. However, a Doppler shift occurs in the received wave R2 by the amount corresponding to the flying speed of the droplet.

On the other hand, when the liquid droplet is detached, the liquid droplet disappears from the tip of the discharge needle N and a boundary with air is formed. When the excitation wave G is reflected at this boundary, a reflected wave R1 is generated. Both the reflected wave R1 and the received wave R2 are alternating currents that propagate from the distal end side to the root side of the ejection needle N, and a beat DB is generated by superposition of the received wave R2 and the reflected wave R1.
FIG. 11 is a graph of the electromagnetic wave intensity change actually observed in the discharge needle N. FIG. The figure shows the intensity change of the electromagnetic wave component based on the alternating current propagating from the distal end side to the root side of the ejection needle N. As shown in the figure, when the liquid droplet starts to be ejected, the reception intensity becomes strong, and when the liquid droplet is detached, the reception intensity once returns to the original level. Then, it can be seen that the beat DB is generated by receiving the reception wave R2 and the reflection wave R1. In this embodiment, the detachment speed of the droplet is obtained using this beat DB.

The droplet separation speed U can be calculated using the following equation (2). The following equation (2) is obtained by modifying the following equation (1) that represents the frequency fb of the beat DB.

In the expressions (1) and (2), f is a microwave frequency excited by the cavity resonator 11, and c is the speed of light. The beat fb is an actual measurement value obtained from the electromagnetic wave received by the receiving unit 20.

If the separation speed U is obtained, the discharge amount V can be calculated by the following equation (3).

In the above equation (3), τ is the time from the start of the discharge of the detached droplet to the separation from the tip of the discharge needle, and d is the inner diameter of the discharge needle. As described above, τ can be easily obtained based on the intensity change of the reflected wave.

However, in a system in which the distance from the tip of the ejection needle N to the landing point of the droplet is less than the distance to fly during one beat period, the whole beat DB does not appear in the actual measurement result. Therefore, the beat DB frequency fb required for the equation (2) cannot be obtained based on the electromagnetic wave received by the receiver 20.
The flight distance δ corresponding to one period of beat is calculated by the following equation (4).

In the equation (4), λ is the wavelength of the microwave with the frequency f. As shown in the equation (4), it can be seen that the travel distance δ is an amount that does not depend on the flying speed of the droplet. It can also be seen that one period of beat is observed in the half period of the oscillated microwave.

  When the equation (4) is used, the flight distance δ when the microwave frequency is 24 GHz is 6.25 mm. That is, in order to observe beats for one period, it is understood that a space that allows droplets to fly 6.25 mm or more is necessary. If the measurement system can secure this distance, the droplet separation speed can be obtained by the above method, but there are many systems that cannot secure the distance of 6.25 mm.

  Therefore, in a measurement system that cannot secure a flight distance corresponding to one period of the beat frequency fb from the tip of the discharge needle N to the landing point of the droplet, a method of estimating the frequency by mapping a sine wave to a beat waveform, It is possible to adopt a method of detecting the zero cross start and the lower end of the amplitude at 90 ° and considering this as a quarter cycle. However, even in the latter case, a flight distance of 1.56 mm is required with 24 GHz microwave, and in any case, it is necessary to secure a landing distance of a predetermined distance or more.

  In the former method, a beat waveform is captured by a high-speed ADC (analog / digital converter), and sine wave mapping is performed on the captured waveform. However, since the sampling period is not an angular function, it is inevitable that the estimation equation is quite complicated. Further, since there is a problem that it is difficult to determine how much sampling contributes to the beat, it is preferable to perform the latter method.

(4) Detection process:
The detection process performed in the detection apparatus 100 demonstrated above is demonstrated with reference to FIG. FIG. 12 is a flowchart of the detection process executed by the control unit 32. It should be noted that the present detection process is not only executed programmatically as in the control unit 32, but may be configured such that an arithmetic process equivalent to the main detection process is executed by an electric circuit or an electronic circuit.

  In addition, the detection apparatus 100 displays a detection process result, an operator instructs the detection apparatus 100 to start detection, displays the detection process result, and sets a display method for the result. An operation input unit may be provided. However, a display and an operation input unit are not essential. For example, an external computer is connected to the detection apparatus 100 and the detection apparatus 100 is controlled via the external computer, or an analysis result output from the detection apparatus 100 is acquired by the external computer. May be omitted.

  When the detection process is started by performing a predetermined operation at the operation input unit, in step S100 (hereinafter, “step” is omitted), the control unit 32 outputs a predetermined output from the reception unit 20. The process of acquiring the electromagnetic wave intensity data of the microwave frequency is started. This acquisition process is continued until this detection process ends.

  In S105, the control unit 32 determines whether or not the acquired electromagnetic wave intensity exceeds a predetermined threshold value. When the predetermined threshold is exceeded, the time exceeding the predetermined threshold is stored in the RAM or the like as the ejection start time t1 and the process proceeds to S110. When the predetermined threshold is not exceeded, the process of S105 is repeated. The predetermined threshold is determined experimentally. For example, the electromagnetic wave intensity when the liquid is attached to the tip of the discharge needle N and the electromagnetic wave intensity when the liquid is not attached to the tip of the discharge needle N Any value between is set.

  In S110, the control unit 32 determines whether or not the acquired electromagnetic wave intensity has zero-crossed. If zero crossing has occurred, the zero crossing time is stored in the RAM or the like as the discharge end time t2, and the process proceeds to S115. If zero crossing has not occurred, the process of S110 is repeated.

  In S115, the control unit 32 performs zero-crossing and analyzes the subsequent electromagnetic wave intensity to obtain the beat DB frequency. The frequency of the beat DB can be acquired using any of the methods described above. For example, in a measurement system that can secure a flight distance for one period of beat DB, the beat DB is defined as the beat period from the time when the zero cross is detected in S110 to the detection time of the next zero cross detected next. The frequency fb is calculated.

  In S120, the control unit 32 calculates the separation speed U by performing the calculation of the equation (2) using the frequency fb calculated in S115, and uses the separation speed U as the discharge amount per unit time of the liquid. Assuming that the liquid discharge amount V is calculated by performing the calculation based on the equation (3).

  In S125, the control unit 32 displays the discharge amount calculated in S120 on the display, and also displays the detection results such as the discharge start time t1 and the discharge end time t2 as necessary. The operator looks at the discharge amount displayed on the display and performs further discharge if necessary. Of course, if the operator has previously set a target discharge amount via the operation input unit or the like, the control unit 32 determines the discharge amount calculated in S120, and if it is insufficient, additional discharge is performed. Do. In addition, when performing additional discharge, fine adjustment of the discharge amount may be performed by discharging small amounts intermittently, for example, discharging one droplet at a time. When S125 ends, the detection process ends.

(5) Miniaturization of equipment
In putting the above apparatus into practical use, it is assumed that there is a high demand for downsizing. This is because the cavity resonator has to penetrate the discharge needle to the inside, and is likely to be attached to a movable part operated by a robot. Moreover, it is preferable that it is small also from the workability | operativity of replacement at the time of reusing this detection apparatus with a some apparatus. Therefore, it is preferable that the resonance cavity that penetrates the discharge needle is particularly small and light, and the number of members that are integrally formed with the cavity resonator is preferably as small as possible. A configuration example for reducing the size and weight of the cavity resonator 11 and a portion handled integrally with the cavity resonator 11 is shown in FIGS.

  FIG. 13 is a block diagram illustrating a configuration example of the detection apparatus. In the figure, the main part of the detection device 200 is a cavity resonator 211 and a micro wave that introduces a microwave into the cavity resonator 211 with a loop antenna to excite the TM01 mode and receives the microwave with the loop antenna. A wave unit 212, a high-frequency cable 213 that transmits a microwave received by the microwave unit 212, and a Doppler unit 214 that detects a beat DB in a desired frequency band from the microwave input via the high-frequency cable 213. ing.

  In the above configuration, the cavity resonator 211 and the microwave unit 212 are integrated, and the Doppler unit 214 is configured separately from the cavity resonator 211. Therefore, only the cavity resonator 211 and the microwave unit 212 are required to be disposed in the moving part of the robot, and the demand for miniaturization and weight reduction can be met. However, since the high-frequency cable 213 is very expensive at several tens of thousands of yen, it is better not to use the high-frequency cable in terms of cost. Therefore, in the configuration of FIG. 14, a detection device can be created without using a high-frequency cable.

  In FIG. 14, a detection apparatus 300 includes a cavity resonator 311, a microwave unit 312 that excites a TM01 mode by introducing a microwave into the cavity resonator 311 with a loop antenna, and a cavity resonator 311 with an antenna. A Doppler unit 314 that receives microwaves and detects beat DB of a desired frequency band is provided. In the figure, the microwave unit 312 and the Doppler unit 314 are directly attached to the resonance cavity of the cavity resonator 311. It should be noted that the power supply and the parts that perform various processes are separately provided.

  Here, it will be examined whether or not the Doppler unit 314 can be integrated with the cavity resonator 311. The size of the cavity resonator used in this embodiment is 5.8 mm × 9.5 mm. Commercially available Doppler units include 22 mm × 45 mm × 9 mm and 15 mm × 19 mm. Therefore, it is possible to integrate these into the cavity resonator 311. If it is made exclusively for this detection device, the Doppler unit should be further miniaturized, and it can be seen that it can be miniaturized to a sufficiently practical level. .

(6) Modification 1:
In the embodiment described above, the detection device for grasping the situation near the tip of the discharge needle N has been described. However, as described in the means for solving the problem, the present technology is applicable to the linear conductor. It can also be applied to the purpose of grasping the situation around the tip.
Therefore, in the first modification, an example in which the present technology is used as a so-called touch probe will be described.

  FIG. 15 is a block diagram showing a schematic configuration of this modification. As shown in the figure, the detection device 400 according to the present modification causes a microwave resonator to pass a microwave frequency alternating current through a conductor line L by exciting a microwave standing wave in a TM01 mode in a cavity resonator 411. A state of one end of the conductor by analyzing the electromagnetic wave received by the receiving unit 420, the receiving unit 420 receiving the electromagnetic wave of the microwave frequency radiated from the conductor line L by the alternating current, and the exciting unit 410 that generates current And a detecting unit 430 for detecting.

The conductor line L is a linear conductor such as a piano wire, and is disposed along the center of the rotating magnetic field excited by the cavity resonator 411. The conductor wire L is grounded to the cavity resonator 411 at the root side, like the discharge needle N described above, and the tip end side is formed on the side wall of the cavity resonator 411 without contacting the cavity resonator 411. It is led out from the opening.
Except that the ejection needle N is replaced with the conductor wire L, the corresponding configuration of the above-described embodiment can be appropriately employed for the excitation unit 410, the reception unit 420, and the detection unit 430 of Modification 1.

  In the detection apparatus 400 configured as described above, a strong electric field is formed in all directions at the tip of the conductor line L. When an object approaches the tip of the conductor line L, the electric field changes, and the alternating current I flowing through the conductor line L varies. The detection unit 430 can detect with high sensitivity another object that approaches or contacts the tip of the conductor wire L by monitoring the fluctuation of the alternating current I. Therefore, the touch probe can detect an approach of another substance before an actual contact and can issue an approach alarm. In addition, the touch probe of this modification is advantageous over the conventional touch probe in that other substances can be detected without mechanical strain.

  Furthermore, if configured as in this modification, it can also be used as a minute displacement meter that detects minute movements and vibrations of an object. When the present invention is used as a micro displacement meter, in addition to the configuration of the detection device 400 described above, calibration is performed so that the reception intensity can be obtained as a function of distance. That is, the reflected wave R1 and the received wave R2 described in the above-described embodiment are received, and the nonlinear relationship between the received intensity and the distance from the object to the tip of the conductor line L is calibrated. This relationship is created for each object because the correlation may be different for each object. Further, if the Doppler beat as measured in the above-described embodiment is measured as well as the reception intensity, the relative approach speed and separation speed between the object and the tip of the conductor wire L can be obtained.

(7) Modification 2:
In the above-described embodiment, the description has been given by taking the discharge needle as an example, but the present invention can be realized even when the discharge needle is bent. That is, if the discharge needle is configured to be bendable, the discharge state at the tip of the discharge needle can be grasped outside the hole while the discharge needle is inserted into the inside of the hole bent inside, so that the observation area is unnecessary. The characteristics in are effectively utilized. In the second modification, a case where the detection apparatus of the present invention is used as an apparatus for supplying drinking water to a drinking water vending machine will be described as an example. The principal part of the detection apparatus 500 concerning this modification 2 was shown in FIG.

  As shown in FIG. 16, the detection apparatus 500 according to this modification causes a microwave standing current wave in the TM01 mode to be excited in the cavity resonator 411 so that an alternating current having a microwave frequency flows through the ejection needle N ′. An excitation unit 510 that generates a skin current, a receiving unit 520 that receives an electromagnetic wave having a microwave frequency radiated from the ejection needle N ′ by the alternating current, and an electromagnetic wave received by the receiving unit 520 to analyze one end of the conductor And a detecting unit 530 for detecting the situation.

The discharge needle N ′ is a conductor wire that can be bent, and a hole is formed in the center of the discharge needle N ′. The discharge needle N ′ is grounded to the cavity resonator 511 at the root side, like the discharge needle N described above, and the tip side is formed on the side wall of the cavity resonator 511 without contacting the cavity resonator 11. Is led out from the opening. The discharge needle N ′ is fixed so as not to bend inside the cavity resonator 511, and is disposed along the center of the rotating magnetic field excited by the cavity resonator 511. The discharge needle N ′ can be bent at the tip derived from the cavity resonator 511.
Except that the discharge needle N is replaced with the discharge needle N ′, the corresponding configuration of the above embodiment can be appropriately employed for the excitation unit 510, the reception unit 520, and the detection unit 530 of the second modification.

  According to the detection device 500 configured as described above, the operation of supplying drinking water to a drinking water vending machine becomes extremely easy. For example, the detection device detects the amount of liquid discharged from the discharge needle N ′ and detects the decrease in the reflected wave R1 when the liquid surface touches the tip of the discharge needle N ′ and ends the replenishment operation. 500. On the other hand, a drinking water supply hole H for inserting a nozzle constituted by the discharge needle N 'is provided in the vending machine. It is desirable that the drinking water replenishing hole is provided with a lid and can be locked. The discharge needle N ′ is preferably formed with a mark for determining whether or not the tip of the nozzle has reached the liquid level when the drinking water supply tank is full. In addition, the function of detecting the amount of the replenished liquid is realized by the first discharge needle N ′, and the function of detecting that the drinking water is sufficiently replenished to the replenishment tank is provided by the second discharge needle or the conductor C having no pipe. Can be realized separately.

  By using the above-described detection device 500, an operator can perform a drinking water replenishment operation that is conventionally performed while opening the main door and confirming the amount stored in the drinking water storage tank without opening the main door. You can do it. That is, the operator unlocks the lid, inserts a nozzle into the drinking water supply hole H, and instructs the automatic supply device to supply drinking water. Then, the detection apparatus 500 supplies drinking water while determining whether or not the tip of the discharge needle N ′ is in contact with the liquid surface at predetermined time intervals. When the detection device 500 detects that a change that only indicates that the tip of the discharge needle N ′ is in contact with the liquid level has occurred in the alternating current flowing through the discharge needle N ′, the drinking water has filled the storage tank. Determine and stop the liquid supply mechanism. Thus, since the replenishment of drinking water is automatically completed, the operation | work which an operator performs becomes very easy.

An experimental example showing that the state of the tip of the discharge needle N ′ can be detected by the detection device 500 of the second modification is shown in FIG. FIG. 17 shows the electric field distribution measured with a stainless steel fine wire bent at R10 mm.
As shown in the figure, even a bent stainless steel wire. It can be seen that the electric field propagates along the line. Therefore, the excitation wave G as in the above-described embodiment propagates to the bent tip, and the reflected wave R1 reflected from the tip of the bent discharge needle N ′ is reflected and propagates to the root side. It can be seen that the received wave R2 received at the tip of the ejection needle N ′ also propagates to the root side.

(8) Modification 3:
By the way, bubbles may be generated in the discharged liquid. When the liquid in which bubbles are mixed is discharged, the discharge amount is deviated, so that the reliability of the process is lowered. For example, bubbles having a high viscosity such as an adhesive are highly likely to be generated. However, if the amount of the discharged adhesive is different from a specified amount, the reliability of the process is lowered. Therefore, in the third modification, a method for detecting whether or not bubbles are mixed in continuously ejected liquid is proposed.

  Although the detection devices 100, 200, 300, 400, and 500 according to the above-described embodiments are targeted for detection of the intensity of the electromagnetic wave radiated based on the “excitation wave G”, the “reflected wave R1”, and the “received wave R2”. If the method of the present invention is used, an alternating current (hereinafter referred to as “reflected wave R3”) reflected at the interface S1 of the bubble B formed in the discharged liquid can also be detected. FIG. 18 is a diagram showing a current generated at the tip of the discharge needle when the liquid is continuously discharged from the discharge needle N ″.

  In FIG. 18, “excitation wave G”, “reflected wave R1”, and “reflected wave R3” are generated at the tip of the ejection needle N ″. As shown in the figure, the bubble B formed in the liquid travels in the ejection direction at substantially the same speed U ″ as the liquid ejection speed U. Therefore, the reflected wave R3 reflected by the interface S1 has a velocity U "Doppler shift occurs. That is, an alternating current obtained by superimposing the reflected wave R3 and the reflected wave R1 generates a Doppler beat DB ". Note that the Doppler beat DB" is a phenomenon before a droplet is detached from the tip of the ejection needle N ". Therefore, it can be clearly distinguished from the Doppler beat DB of the above-described embodiment. Note that the Doppler beat DB "generated in the third modification is also a method similar to that of the above-described embodiment. Can be detected.

  When the Doppler beat DB ″ is detected, the fluctuation range ΔI of the amplitude of the Doppler beat DB ″ is measured. This fluctuation width ΔI corresponds to the intensity of the reflected wave R3. If the fluctuation width ΔI exceeds a predetermined value, it can be determined that the reflected wave R3 is generated. That is, whether or not bubbles are mixed in the discharged liquid can be detected based on the amplitude of the Doppler beat DB ″.

(9) Modification 4:
In the embodiment described above, the antenna is used as the antenna of the receiving unit as an example. However, the means for measuring the electric field strength of the electromagnetic wave radiated to the space is not limited to this.
FIG. 19 shows another example of a receiving unit that measures electromagnetic waves. This figure shows an electric field sensor using an electro-optic crystal (EO crystal) whose refractive index changes when an electric field is applied. The electro-optic effect (EO effect) includes a Pockels effect and a Kerr effect, but an EO crystal having a Pockels effect is often used for an electric field sensor using an EO crystal. This is because the amount of change in the refractive index is linearly proportional to the electric field strength, so that calibration is easy.

<Receiver configuration>
In FIG. 19, the reception unit 620 includes an electric field sensor 621 and a polarization processing unit 622. The electric field sensor 621 includes a reflective film 621a formed of a dielectric, an EO crystal 621b, a collimator lens 621c, a ferrule 621d, and an optical fiber 621e in order from the tip. The rear end of the optical fiber 621e is connected to an optical fiber connector, and is connected to the polarization processing unit 622 via this optical fiber connector. Note that, for example, a 1 mm square EO crystal can be used. Therefore, the electric field sensor 621 can be made smaller than an electric field sensor (having a length of several centimeters to several tens of centimeters) using a conventional dipole antenna.

<Movement of light in electric field sensor>
In the receiving unit 620, the tip of the optical fiber 621e is connected perpendicularly to the EO crystal 621b. In the EO crystal 621b, a light incident surface that is a plane on which light is incident from the optical fiber 621e and a reflective surface that is a plane on which the reflective film 621a is formed are formed in parallel to each other. The reflective film 621a reflects light that has reached the reflective surface from the inside of the EO crystal 621b. Accordingly, the incident light incident from the optical fiber 621e is perpendicularly incident on the incident surface, reaches the reflecting surface as it is, is reflected vertically by the reflecting surface, and is incident on the optical fiber 621e again.

  The reflected light incident on the optical fiber 621e maintains the same polarization state as the incident light when the EO crystal is not irradiated with electromagnetic waves. This is because the refractive index of the EO crystal 621b has not changed. On the other hand, since the refractive index changes when the EO crystal is irradiated with electromagnetic waves, the reflected light incident on the optical fiber 621e changes to a polarization state different from the incident light. The polarization processing unit 622 converts a change in the polarization state into a change in light intensity by the analyzer 622a and the like, and outputs a signal corresponding to the electric field intensity of the electromagnetic wave by converting the light intensity conversion into an electric signal. If the signal according to the electric field strength obtained in this way is analyzed by the analysis processing unit of the above-described embodiment or modification, the covering state can be inspected.

In addition, the phase change occurs in the light when transmitting the optical fiber, but the same phase change occurs in both the incident light that goes up the optical fiber and the reflected light that goes down the optical fiber, so the phase change cancels up and down, Phase change in the optical fiber can be made zero.
In addition, the electric field sensor 621 of the present embodiment can accurately capture the state of the original electromagnetic wave that is to be measured. The EO crystal 621b, the collimator lens 621c, and the ferrule 621b do not contain metal, and the reflective film 621a is formed of a dielectric, and can transmit a signal to the polarization processing unit 622 through the optical fiber 621e. This is because the electromagnetic waves that are radiated are not disturbed and electrical coupling does not occur even if they are arranged in the vicinity of the measurement object.

(10) Summary:
The detection device 100 according to the embodiment described above excites a standing wave of an electromagnetic wave having a microwave frequency in the TM01 mode in the cavity resonator 11 in the detection device 100 that detects the discharge state of the liquid at the tip of the discharge needle N. The excitation unit 10 for flowing an alternating current I having a microwave frequency to the discharge needle N arranged along the center of the rotating magnetic field of the TM01 mode by electromagnetic induction, and the discharge current N is emitted from the discharge needle N when the alternating current I flows. The receiving unit 20 that receives the electromagnetic wave to be received, and the detection unit 30 that detects the presence / absence of ejection and the ejection amount at the tip of the ejection needle N based on the electromagnetic wave received by the receiving unit 20 are provided. Therefore, the detection apparatus 100 can grasp the situation in the vicinity of the tip even if there is no observation space near the tip of the linear conductor.

  Note that the present invention is not limited to the above-described embodiments and modifications, and the structures disclosed in the above-described embodiments and modifications are mutually replaced, the combinations are changed, the known technique, and the above-described implementations. Configurations in which the configurations disclosed in the embodiments and modifications are mutually replaced or the combinations are changed are also included.

DESCRIPTION OF SYMBOLS 10 ... Excitation part, 11 ... Cavity resonator, 11a ... Cylindrical side wall, 11b ... End side wall, 11c ... End side wall, 11c1 ... Opening, 12 ... Microwave unit, 20 ... Reception part, 21 ... Antenna, 22 ... BPF, 23 ... Amplifier, 24 ... Detector, 30 ... Detector, 31 ... A / D converter, 32 ... Control part, 100 ... Detector, 200 ... Detector, 211 ... Cavity resonator, 212 ... Microwave Unit: 213 ... High-frequency cable, 214 ... Doppler unit, 300 ... Detector, 311 ... Cavity resonator, 312 ... Microwave unit, 314 ... Doppler unit, 400 ... Detector, 410 ... Excitation unit, 411 ... Cavity resonance 412 ... Microwave unit 420 ... Receiving unit 430 ... Detecting unit 500 ... Detecting device 510 ... Excitation unit 511 ... Cavity resonator 512 ... My 620 ... receiving unit, 620 ... receiving unit, 621 ... electric field sensor, 621a ... reflective film, 621b ... EO crystal, 621c ... collimator lens, 621d ... ferrule, 621e ... optical fiber, 622 ... Polarization processing unit, 622a ... analyzer, C ... conductor, G ... excitation wave, I ... alternating current, L ... conductor wire, N ... ejection needle, R1 ... reflected wave, R2 ... received wave

In order to solve the above-described problems, the detection device of the present invention is a detection device that detects a situation at one end of a linear conductor, and excites a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode. Then, an electromagnetic wave is transmitted through an excitation unit that causes the alternating current of the predetermined frequency to flow through the conductor having the other end inserted into the cavity resonator by electromagnetic induction, and a receiving antenna disposed inside the cavity resonator. A receiving unit for receiving , detecting an intensity change of a radiated wave radiated by the alternating current based on an intensity change of an electromagnetic wave received by the receiving unit, and at the one end of the conductor based on an intensity change of the radiated wave And a detector that detects electric field fluctuations . The situation here, or a presence or absence of an object to be attached to the one end, or a presence or absence of an object which is disposed close to said one end, or a presence or absence of an object approaching or away from the first end . More specifically, there is a conductive material is attached to the tip, or conditions and adhesion to have conductive material is detached from the front end, while the interface that can reflect electromagnetic waves are close to the distal end, or spaced The situation is being illustrated.

That is, the detection unit is caused by the component radiated due to the alternating current reflected at the one end or the alternating current generated due to the electromagnetic wave received at the one end in the electromagnetic wave received by the receiving unit. The amount that varies depending on the component emitted is detected. Based on the detected fluctuation amount, the situation at the one end is detected. That the detector is the object that generates an electromagnetic interaction between the tip of the conductor determines whether present in the vicinity of the front end of the conductor.

Incidentally, as a selective one aspect of the present invention for supplying efficiently alternating current to the conductor by the cavity resonator, the excitation portion, a standing wave of TM01 mode of a predetermined frequency to the cavity resonator excited, the conductor may be disposed along the center of the rotating magnetic field of the TM01 mode.
In the TM01 mode, an electric field is concentrated at the center of the rotating magnetic field, and the electric field vector at the center of the rotating magnetic field is determined in one direction. That is, by arranging the linear conductor along the center of the rotating magnetic field, the sum of the electric field vector passing through the conductors is maximized, the alternating current flowing through the conductor from the standing wave of the cavity resonator Conversion efficiency is maximized.

As selective one aspect of the present invention to enhance the effects of conditions of the end with respect to alternating current, wherein the excitation portion by exciting a standing wave of a microwave band to the cavity resonator, the You may make it let the alternating current of a microwave frequency flow through a conductor.
The alternating current of microwave frequency becomes a skin current in the conductor. When the AC current becomes a skin current, most of the current flows from the outer edge of the conductor to the skin thickness, so that the interaction between the AC current and the outside is maximized. That is, the influence of the situation at the one end becomes more prominent in the alternating current.

As selective one aspect of the present invention for improving the detection accuracy of the status of the one end, alternating current flowing in the conductor has become a standing wave, the conductor, the tip of the standing wave The length may substantially match the stomach.
When the length of the ejection needle N is adjusted so that the position of the antinode of the standing wave substantially coincides with the tip of the conductor, the intensity of the reflected wave R1 in a state where no object is attached to the tip of the conductor. Is maximized. When an object adheres to the tip of the conductor, the reflection position of the excitation wave G shifts or the reflection intensity changes, so that the intensity of the standing wave varies.

As a selective one aspect of the present invention for detecting a situation in which the liquid is discharged from the tip of the linear conductor when the linear conductor is tubular and the liquid passes through the inside thereof, The conductor is a tube, and the detection unit detects a timing at which the intensity of the radiated wave exceeds a predetermined threshold as a liquid discharge start timing of the tube, and then the intensity of the radiated wave has a predetermined intensity. You may comprise so that the timing which becomes lower than a threshold value may be detected as completion | finish timing of the liquid discharge of the said pipe | tube .
According to this configuration, when liquid is discharged from the tip of the conductor through the tube, the liquid adheres to the tip. Then, since the intensity of the electromagnetic wave received by the receiving unit changes, it is possible to detect the discharge state of the liquid based on this change. Further, since the intensity of the electromagnetic wave received by the receiving unit also changes when the liquid adhering to the tip of the conductor is detached from the tip, it is possible to detect the state of separation of the liquid based on this change.

Further, when the linear conductor is tubular and the liquid passes through the inside, the detection unit determines the amount of the liquid discharged from the one end through the tube as the liquid delivery speed. It is also possible to detect based on the start timing of the liquid discharge and the end timing of the liquid discharge . The liquid delivery speed may be obtained from a liquid delivery device, but the detection unit is based on the Doppler beat frequency fb of the radiated wave and the frequency f of the electromagnetic wave excited by the cavity resonator. The separation rate U of the liquid discharged from the one end through the pipe is calculated by the following equation (A), and the amount of the liquid is detected by regarding the separation rate U of the liquid as the liquid delivery speed. it can.
U = c × fb / 2f (A)
(In the formula (A), c is the speed of light.)
That is, when the liquid leaves, electromagnetic waves radiated from the tip based on the alternating current are reflected from the liquid surface and returned to the tip. This electromagnetic wave is received again at the tip, and an alternating current (received wave) is generated in the conductor. In addition, an alternating current (reflected wave) in which the alternating current induced by the excitation unit is reflected at the boundary between the gas phase and the leading edge also flows at the tip. The received wave has a Doppler shift corresponding to the flying speed of the liquid, and the frequency is slightly lower than that of the reflected wave. Therefore, a Doppler beat occurs due to the superposition of the received wave and the reflected wave. If the Doppler beat frequency is measured, the flying speed of the liquid can be obtained. This flying speed is a separation speed of the liquid from the tip, and can be regarded as a discharge speed of the liquid. Therefore, the discharge amount can be obtained by multiplying the discharge speed by the cross-sectional area of the tube and the time during which the discharge is continued.

Even if the conductor is not tubular, when an object approaches the tip of the conductor, Doppler beats occur in the electromagnetic wave, and when the object moves away from the tip of the conductor, Doppler is also applied to the electromagnetic wave. A roar occurs. Therefore, the detection unit may detect the amount of displacement between the one end and the object based on the electromagnetic wave received by the reception unit. That is, the distance between the object and the detection device can be measured.
Further, since the alternating current fluctuates not only according to the Doppler beat, but also depending on the distance between the object and the tip , the relationship between the received intensity of the radiated wave and the distance from the one end to the predetermined object was calibrated. By storing the correspondence relationship, the distance between the object and the detection device can be measured based on the correspondence relationship and the intensity of the radiation wave, and the displacement amount and displacement history of the object can be acquired. You can also

As described above, according to the present invention, it is possible to provide a detection device that can grasp the situation in the vicinity of the tip of the linear conductor even when there is no observation space in the vicinity of the tip.
Moreover, according to the invention concerning Claim 2, detection sensitivity can be improved.
According to the invention of claim 3, since the conversion efficiency into alternating current can be improved, the detection sensitivity is improved.
Moreover, according to the invention concerning Claim 4, detection sensitivity improves.
Moreover, according to the invention concerning Claim 5, detection sensitivity improves.
According to the sixth aspect of the present invention, even when there is no observation space near the tip of the linear conductor, it is possible to know the discharge state of the liquid discharged from the tip.
According to the seventh and eighth aspects of the present invention, even when there is no observation space near the front end of the linear conductor, the discharge amount of the liquid discharged from the front end can be known.
According to the ninth aspect of the invention, it is possible to provide a micro displacement meter using electromagnetic waves, particularly microwaves, and it is possible to provide a microwave proximity switch using the same.
According to the invention of claim 10, the circuit configuration of the receiving unit and the detecting unit can be reduced.
According to the eleventh aspect of the invention, the number of antennas can be reduced.
According to the twelfth aspect of the present invention, it is possible to provide a detection method capable of grasping the situation near the tip of the linear conductor even if there is no observation space near the tip.
According to the thirteenth aspect of the present invention, it is possible to provide a control program for controlling a detection device that can grasp the situation near the tip of the linear conductor even when there is no observation space near the tip of the linear conductor.

To solve the above problem, the detection device of the present invention is a detection device that detects the status at one end of the linear conductor, the cavity resonator, the electromagnetic wave of a predetermined frequency to the cavity resonator constant An excitation unit that excites a standing wave in the TM01 mode and a resonance cavity of the cavity resonator penetrate in the electric field direction of the standing wave, and an alternating current of the predetermined frequency flows by electromagnetic induction of the standing wave The linear conductor, a receiving unit that receives electromagnetic waves via a receiving antenna disposed inside the cavity resonator, and radiated by the alternating current based on an intensity change of the received electromagnetic waves of the receiving unit. comprising the a detecting section that detect changes in the intensity of the radiation wave, the, the linear conductors are grounded in any position on the side nearer the other end of the linear conductor than the resonant cavity And located closer to the one end than the resonant cavity. The electric field generated by electromagnetic induction of the standing wave in the axial direction of the linear conductor is directed toward the one end, and the detection unit is configured to change the intensity of the radiated wave based on the intensity change of the radiation wave. The electric field fluctuation at one end is detected . The situation here refers to the presence / absence of an object attached to the one end, the presence / absence of an object disposed close to the one end, or the presence / absence of an object approaching or separating from the one end. . More specifically, the conductive material adheres to the tip, or the attached conductive material is detached from the tip, or the interface that can reflect electromagnetic waves is approaching or separated from the tip. The situation is being illustrated.

Claims (11)

A detection device for detecting a situation at one end of a linear conductor,
An excitation unit that excites a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode, and causes an alternating current of the predetermined frequency to flow through the conductor having the other end inserted into the cavity resonator by electromagnetic induction;
A receiver for receiving electromagnetic waves radiated from the conductor;
A detection unit for detecting a situation at the one end of the conductor based on an electromagnetic wave received by the reception unit;
A detection apparatus comprising:   The conductor is grounded in any part of the excitation unit that is closer to the other end of the linear conductor than a part that induces an alternating current using the cavity resonator. Detection device.   3. The excitation unit excites a standing wave of a TM01 mode having a predetermined frequency in the cavity resonator, and the conductor is disposed along substantially the center of a rotating magnetic field of the TM01 mode. The detection device according to 1.   The said excitation part flows the alternating current of a microwave frequency to the said conductor by exciting the standing wave of a microwave frequency to the said cavity resonator, The any one of Claims 1-3 characterized by the above-mentioned. Detection device. The alternating current flowing through the conductor is a standing wave,
The inspection device according to any one of claims 1 to 4, wherein the conductor has a length substantially matching a tip of the standing wave. The conductor is a tube,
The said detection part detects the timing when the discharge of the liquid was started from the said one end through the said pipe | tube, and the timing when the discharge of the liquid was complete | finished based on the electromagnetic waves which the said receiving part received. The detection device according to any one of the above. The conductor is a tube,
The detection device according to claim 1, wherein the detection unit detects an amount of liquid ejected from the one end through the tube based on an electromagnetic wave received by the reception unit. . The conductor is a tube,
The said detection part detects the separation speed of the liquid discharged from the said one end through the said pipe | tube based on the Doppler beat in the electromagnetic waves which the said reception part received. The detection device described.   The detection device according to claim 1, wherein the detection unit detects a distance between the one end and an object based on an electromagnetic wave received by the reception unit. A detection method for detecting a situation at one end of a linear conductor,
Exciting a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode, and passing an alternating current of the predetermined frequency to the conductor having the other end inserted into the cavity resonator by electromagnetic induction;
A receiving step of receiving electromagnetic waves radiated from the conductor;
A detection step of detecting a situation at the one end of the conductor based on the electromagnetic wave received in the reception step;
A detection method comprising: A detection program for controlling a detection device for detecting a situation at one end of a linear conductor,
An excitation function for exciting a standing wave of an electromagnetic wave having a predetermined frequency in a cavity resonator in a TM01 mode, and causing an alternating current of the predetermined frequency to flow through the conductor having the other end inserted into the cavity resonator by electromagnetic induction;
A receiving function for receiving electromagnetic waves radiated from the conductor;
A detection function for detecting a situation at the one end of the conductor based on an electromagnetic wave received by the reception function;
A detection program for causing a detection device to realize the above.