JP2016051438A - Container, fluid volume management system and fluid volume management method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container capable of easily managing a fluid volume inside a sealed container without wiring.SOLUTION: A container is capable of communicating with an external transmitting/receiving unit. The container includes an accommodation part and an RFID tag. The accommodation part accommodates fluid and includes a metal portion having a slot formed at least in an outside surface of a side wall. The slot does not communicate with an inside surface of the side wall. An IC chip is mounted onto the slot in the metal portion of the accommodation part. The RFID tag is configured with the slot and the IC chip and communicates with the external transmitting/receiving unit at an intensity corresponding to a fluid surface position inside the accommodation part.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a container, a liquid amount management system, and a liquid amount management method.

  Conventionally, management of the amount of liquid in a container includes visual detection, a float detection method, and a detection method using a CCD / light / ultrasonic sensor.

  However, when the container is not necessarily transparent and needs to be sealed, liquid management cannot always be performed visually. As a method other than visual observation, for example, Patent Document 1 discloses a float detection method as shown in FIG. 13 and detects a liquid level with a float 82 suspended from a string 81 in a container 80. .

  As a method using a sensor, for example, in Patent Document 2, a photoelectric sensor is used as a position sensor. In addition, as an example of the method managed by the sensor, other contact type limit sensors may be used. Furthermore, a float type detection means (mechanism + detection sensor), other position detection methods such as a CCD line sensor (light projection / light reception type sensor), and the like are also conceivable.

  In addition, for detection of solid metal, an RFID installed on the surface of a metal object has been proposed (see, for example, Patent Document 3).

  In the method of Patent Document 1, the container 80 cannot be sealed in order to hang the string, and the string 81 may be caught and erroneously detected, and the apparatus is complicated.

  When a sensor is used as in Patent Document 2, a line is necessary, and there is a restriction on the location of the sensor in the container.

  As in Patent Document 3, RFID is used for an external transmission / reception unit such as detection and identification of solid metal. However, when the UHF frequency band is liquid, the RFID communication strength changes. For this reason, it has been considered unsuitable for the management of containers containing liquids.

  Therefore, in view of the above circumstances, the present invention provides a container in which the amount of liquid in a sealed container can be easily managed without wiring, which solves the above problems.

In order to solve the above problems, the present invention has the following means.
In one proposal, the container is capable of communicating with an external transmitting / receiving unit, and includes a metal portion that contains a liquid and has a slot formed at least on an outer side surface of the side wall, and the slot includes an inner side surface of the side wall. An IC chip is attached to the slot of the housing part and the metal part of the housing part, which is not communicated, and is formed by the slot and the IC chip, and has the strength according to the liquid surface position in the housing part and the external transmitting / receiving part And an RFID tag that communicates with each other.

  The amount of liquid in a sealed container can be easily managed without wiring.

It is explanatory drawing which shows an example of a structure of a liquid quantity management system. It is a flowchart about operation | movement of the system of FIG. (A) shows the configuration of a dipole antenna as a comparative example, (b) shows the dimensions of (a), and (c) shows the liquid level position and communication when using the antenna of this comparative example. The characteristic view which shows the relationship with distance is shown. It is the schematic of the integrated RFID tag which concerns on Embodiment 1, and the container provided with this RFID tag. It is the schematic of the sticking type RFID tag which concerns on Embodiment 2, and the container provided with this RFID tag. (A) shows the outline of the horizontal antenna used in Embodiment 2, (b) shows the dimensions of (a), (c) shows the liquid surface position and communication distance when this antenna is used. The characteristic view which shows the relationship is shown. (A) shows the outline | summary of the vertical antenna used in Embodiment 2, (b) shows the dimension of (a), (c) is the liquid level position and communication distance when this antenna is used. The characteristic view which shows the relationship with is shown. It is the schematic of the sticking type RFID tag which concerns on Embodiment 3, and the container provided with two or more of this RFID tag. It is the schematic of the sticking type RFID tag which concerns on Embodiment 4, and the container in which this RFID tag was provided variably. (A) is an enlarged view of the IC chip module provided in the integrated RFID tag according to Embodiment 5, (b) is a cross-sectional view of the IC chip module of (a), and (c) is of (a). It is a block diagram with which the IC chip module was attached to the container. (A) is a schematic view of a container provided with an integrated RFID tag and covered with a cover, and (b) is a schematic view of a container provided with an integrated RFID tag and wrapped in a bag. It is the schematic of piping provided with the RFID tag which concerns on embodiment of this invention. It is the schematic of the container which concerns on a prior art example.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

<Overall configuration>
FIG. 1 is an explanatory diagram illustrating an example of a configuration of a liquid amount management system. In this system, according to the state of communication between the RFID reader / writer (reader / writer) and the RFID tag, the state of the liquid level is read, the predetermined amount is grasped by the control means, and the amount of liquid to be fed is controlled, A valve (adjusting means) 400 restricts the amount of liquid in the container.

  The liquid amount management system 1000 includes an RFID tag 500, an RFID reader / writer 200, a control unit 300, and an adjustment unit (valve) 400 for managing the amount of liquid in the container or pipe 100.

  The RFID tag 500/600 is a flat slot antenna installed or integrally formed in the container or pipe 100, monitors the liquid level information in the container or pipe 100, and transmits the monitoring result (reflects, returns). To do). More specifically, the RFID tags 500/600 receive radio waves supplied from the RFID reader / writer 200 and generate electric power by rectification. Then, processing is executed with the electric power generated in the RFID tag 500/600, and data (ID or the like) in the RFID tag is returned (transmitted).

  When this data is put on radio waves and sent back to the RFID reader / writer 200, the communication strength changes depending on the positional relationship between a preset liquid level threshold and the liquid level in the container or pipe 100 (liquid level position). To do. The RFID reader / writer 200 receives the signal with a communication strength corresponding to the positional relationship with the liquid level (liquid level position) (details will be described later together with FIG. 5). In a plurality of embodiments of the present invention, the RFID tag 500/600 is a passive tag without a power source, and supports communication in the UHF band (860 to 960 MHz).

  The RFID reader / writer 200 supplies (radiates) a radio wave (electromagnetic wave) to the RFID tag 500/600, and the RFID tag 500/600 returns the radio wave, thereby transferring (communication) data (liquid level detection result). )I do. That is, the liquid level information is detected based on the strength of the returned radio wave (communication strength). In any of the embodiments of the present invention, IU-9061 (registered trademark) manufactured by Mars or V750 (registered trademark) manufactured by OMRON is used as the RFID reader / writer 200. These RFID readers / writers perform communication at 920 to 950 MHz.

  As the control means 300, a liquid level position interpretation unit 301, a calculation setting unit (computer) 302, and a valve adjustment unit (supply liquid amount control unit) 303 are provided. The control means 300 controls the amount of liquid supplied into the container or the pipe 100 according to the read liquid amount.

  The valve 400 serving as the adjusting unit adjusts the amount of liquid supplied into the container or the pipe so that the amount of liquid controlled by the control unit 300 is obtained.

  FIG. 2 is a flowchart for the operation of the system of FIG. First, in S101, the RFID tag 500/600 installed in the container or piping communicates with the reader / writer 200. Although details will be described later, the RFID tag of the embodiment of the present invention is a slot antenna. The RFID tag 500/600 communicates with a reader / writer which is an external transmission / reception unit with an intensity corresponding to the liquid level position. The container or pipe 100 provided with the RFID tag 500/600 and the RFID reader / writer 200 communicate with each other at a predetermined distance of several meters depending on the direction of the RFID tag and the communication output of the reader / writer. Is done.

  In S102, the liquid level position interpretation unit 301 of the control means 300 interprets the liquid level position in the container or the pipe according to the communication status (the radio wave returned from the RFID tag) received by the RFID reader / writer 200.

  In S103, the amount of liquid supplied to the container or the pipe 100 (the amount of liquid supplied) is calculated and set by the calculation setting unit 302 of the control means 300 according to the read liquid surface position. As the setting of the liquid supply amount, the supply start from the liquid supply stop state and the supply stop from the liquid supply state may be set as the liquid supply amount increases or decreases.

  In S <b> 104, the valve adjustment unit 303 of the control unit 300 adjusts the supply amount of the liquid into the container or the pipe 100 by controlling the valve 400 so that the desired liquid amount is obtained. The adjustment of the liquid supply amount is not only to increase or decrease the liquid supply amount, but also to open the valve 400 so that the liquid supply is started or to stop the liquid supply. Also includes setting to close. Moreover, you may control the kind of liquid supplied in the container or the piping 100 according to the liquid volume read.

  In S105, the valve 400 supplies the liquid with the adjusted liquid amount. Alternatively, the supply from the valve is started or stopped.

  In any embodiment of the present invention, by using such a liquid quantity management system, the liquid quantity in the container or the pipe can be managed remotely.

  Here, in the UHF band used in a plurality of embodiments of the present invention, since the movement of molecules generally interferes with radio waves, the communication status tends to be easily influenced by moisture and metal.

  For example, generally, an RFID tag constituting an antenna device in the UHF band is installed on the outer surface of the side wall of the container, and liquid is poured into the container with the distance between the RFID tag and the reader / writer kept constant. Then, the minimum output of the RFID reader / writer required when reading the ID (Identifier) of the RFID tag varies depending on the position of the liquid surface.

  Specifically, when the liquid level is below the IC chip (communication unit) of the RFID tag, the ID can be read with the output of the reader / writer relatively low. When a large amount of liquid is poured into the container and the liquid level approaches the upper end of the IC chip of the RFID tag (the upper end of the antenna device in the height direction of the container), the ID is read unless the output of the RFID reader / writer is increased. Can not be.

  Using this property, in the embodiment of the present invention, the liquid level position in the container or the pipe 100 is detected according to the communication status. However, in order to realize this liquid amount management, an RFID tag including all antenna devices may not be used. As shown in the following embodiment, a planar slot antenna is used as an RFID tag for communication. There must be.

<Comparative example>
Here, as a comparative example, in FIGS. 3 (a) to 3 (c), an experimental example in which the liquid level is managed by a dipole antenna instead of the RFID tag of the slot antenna described in the embodiment described later on the side wall of the container. Indicates. Here, as an example, the dipole antenna is a sticking type, and ALN 9640 (registered trademark) manufactured by Alien Co., Ltd. was used.

  In FIG. 3A, an RFID tag 90 which is a dipole antenna is an affixed antenna label having a dipole antenna element 91 and an IC chip 92 made of a metal plate (for example, aluminum foil). As a label size of this dipole antenna, as shown in FIG. 3B, the horizontal length of the aluminum foil (dipole antenna element): 8 mm × vertical length: 96 mm.

  FIG. 3C is a characteristic diagram showing the relationship between the liquid surface position and the communication distance when an experiment is performed using the dipole antenna of FIG. FIG. 3C is a characteristic diagram showing the relationship between the liquid surface position of the liquid and the communication distance when the antenna of this comparative example is used. In the graph of FIG. 3C, the horizontal axis represents frequency (MHz), and the vertical axis represents the theoretical forward reading range, that is, communication performance (communication distance: m). From this graph, the change in communication performance was measured when the liquid level was changed from 0 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, and 60 mm from the bottom of the aluminum foil 91 that is a metal member. The read range of the RFID reader / writer can be read from the graph of each frequency shown in the figure.

  As can be seen from FIG. 3C, when the minimum output of the reader / writer required for reading the ID of the RFID tag 90 of this comparative example by the RFID reader / writer is constant, the RFID tag and the reader / writer The communication distance between will change. When the dipole antenna as in this comparative example is used, the communication distance gradually decreases in the vicinity of the communication part (IC chip) of the dipole antenna, and no rapid change is observed. Hard to stick. Therefore, it is not very suitable for measuring the liquid level position.

  Thus, in order to enable detection of the threshold value by changing the strength of the communication distance, in any embodiment of the present invention, a slot antenna is used in the measurement of the liquid surface position. The RFID tag 500/600 and the container (or pipe) 100 provided with the RFID tag 500/600 will be described below.

<< Embodiment 1 >>
FIG. 4 is a schematic view of the RFID tag according to the first embodiment and a container provided with the RFID tag. In the present embodiment, the container 100 includes a metal container 110 such as a stainless steel container and an RFID chip 500. A slot 501 formed of an elongated slit (cut) or groove is directly formed in the metal housing portion 110, and the IC chip 502 is electrically joined to the slot 501 with a conductive agent or the like. In the present embodiment, the slot 501 and the IC chip 502 constitute an RFID tag (integrated RFID tag) formed integrally with the housing part 110. This RFID tag is a planar slot antenna.

  In the present embodiment, as the metal portion of the housing portion, at least the side wall surface of the housing portion 110 is made of metal (metal housing portion). The slot 501 is formed at least on the outer side surface of the side wall of the metal housing part 110, and the slot 501 does not communicate with the inner side surface of the side wall. For example, when the slot 501 is a notch (slit), the inner surface of the portion of the slot 501 of the metal housing portion 110 is made of glass or resin, and the metal housing portion 110 is sealed.

  As an example of the size of the RFID tag 500, in the horizontal antenna shown in FIGS. 4A to 4C, the horizontal length (Ly) of the slot 501 is 188 mm × the vertical length (Lx) is 4 mm. 4D, the slot 501 has a horizontal length of 4 mm × a vertical length of 188 mm.

  Here, when the length (dimension in the longitudinal direction) Ly of the slot 501 is ½ times the wavelength λ of the radio wave used for communication between the RFID antenna and the RFID reader / writer, the slot 501 receives the radio wave. In this case, the voltage generated between both ends of the slot 501 in the X-axis direction becomes the maximum.

  For example, when the wavelength λ is 920 to 950 MHz, Ly = 160 to 200 mm. The width (dimension in the short direction) Lx of the slot 501 is related to the frequency width at which a desired gain (good antenna performance) as an antenna can be obtained. That is, as the width Lx is reduced, the frequency width is reduced. Conversely, as the width Lx is increased, the frequency width is increased. However, as the width Lx is increased, the impedance increases and the efficiency of the antenna decreases.

  In general, the slot 501 is formed by punching using a mold, and is shaped by secondary processing as necessary. In this case, if the width Lx is too narrow, it is difficult to obtain a desired width with a predetermined accuracy. Therefore, it is conceivable to form the slot 501 by laser processing, but this leads to an increase in cost. On the other hand, if the width Lx is too narrow, a foreign object such as a metal piece may be caught in the slot 501 and the antenna performance may be deteriorated. Therefore, when the wavelength λ is 950 MHz, the width Lx is set to 2 to 4 mm. Therefore, for example, in this embodiment and a plurality of embodiments described later, slots with Ly = 188 mm and Lx = 4 mm are used.

  In embodiments of the present invention, ICs such as ALIEN's Higgs3 (registered trademark), Avery Dennison's Impinj Monza3 (registered trademark), NXP G2XL (registered trademark), which can communicate at the UHF frequency, are used as the IC chip in the embodiments. Use a tip. These IC chips are electrically joined with a conductive agent or the like to constitute an antenna. However, the present invention is not limited to this configuration, and any UHF frequency is possible. For example, in this embodiment, the IC chip 502 uses a Higgs3 chip (registered trademark) manufactured by ALIEN.

  When used for measuring the liquid level, the RFID tag is provided on the side wall as shown in FIG. 4 (a) or FIG. 4 (d). In addition, it may be provided in the upper part as shown in FIG. 4 (b) to be used for confirming that the liquid is full, and may be provided in the lower part as shown in FIG. In this embodiment, four RFID tags 500 are provided, but the number of antenna labels is at least as shown in FIG. 4A or FIG. 4D when detecting the threshold of one liquid level. It is sufficient to form it on the side wall.

  The RFID tag 500, which is a slot antenna installed in this way, communicates with the RFID reader / writer 200, which is an external transmission / reception unit, with strength according to the liquid level position of the storage unit 110. Specifically, the RFID tag 500 replies (sends) 920 to 950 MHz radio waves supplied from the RFID reader / writer 200 (see FIG. 1, IU-9061 manufactured by Mars or V750 manufactured by OMRON). The amount of liquid is detected based on the communication situation in which the strength changes according to the amount of liquid. As a premise, the container 100 in which any RFID tag 500 of FIGS. 4A to 4D is installed is installed in an effective communication area which is a space area capable of communicating with the RFID reader / writer 200 outside the container. ing. In the embodiment of FIG. 4, since four RFID tags 500 are provided, the liquid level position interpretation unit 301 is based on the communication characteristics returned from a plurality of RFID tags, that is, the liquid level position information. The liquid level position may be determined.

  Here, the RFID reader / writer 200, as shown in FIGS. 4 (a) and 4 (d), particularly communication characteristics (also referred to as communication information) returned by the RFID tag 500 installed on the side wall. Reception sensitivity or communication. The liquid level is interpreted using the fact that the sensitivity corresponds to the amount of liquid in the container.

  Specifically, in the RFID tag 500 constituting the slot antenna, when there is liquid up to the lower half in the width direction of the slot 501, the returned radio wave is absorbed by the liquid and the communication sensitivity is deteriorated (FIG. 4A). Alternatively, if there is a liquid up to about half of the extending direction of the slot 501 or a little lower than half, the returned radio wave is absorbed by the liquid and the communication sensitivity deteriorates (FIG. 4D). The change in communication sensitivity will be described in detail using the second embodiment. It is preferable to arrange the central part of the IC chip 502 at a place where the communication sensitivity changes.

  Then, control is performed in the control means 300 and the valve 400 as the adjustment means based on the detection result of the amount of liquid.

  In the embodiment of FIG. 4, four RFID tags are provided. Therefore, based on communication information (communication strength) received from the RFID reader / writer 200 and returned from one or a plurality of RFID tags (combination). In addition, the liquid surface position interpretation unit 301 may determine the liquid surface position.

  In the present embodiment, by using the RFID tag 500 constituting the slot antenna, the communication distance changes rapidly, and the liquid level can be detected accurately. Accordingly, the amount of liquid in the container that cannot be seen in a sealed state can be easily confirmed from the outside, and liquid leakage can be prevented. Furthermore, since the liquid level is detected by communication between a passive RFID tag and an RFID reader / writer located at a remote location, no wiring is generated for detection and control of the liquid level. Even it can be detected safely.

<< Embodiment 2 >>
FIG. 5 is a schematic diagram of an RFID tag according to the second embodiment and a container provided with the RFID tag. In the present embodiment, the container 100 </ b> A includes a non-metallic container 120 such as resin or glass, and an RFID tag 600 installed in the non-metallic container 120. In the present embodiment, the RFID tag 600 includes a metal member 601, a slot 602 formed of an elongated slit or groove formed in the metal member 601, and an IC chip 603 electrically joined to the slot 602 with a conductive agent or the like. It is prepared as an antenna label. In the present embodiment, a part of the outer surface of the side wall of the housing part 120 is covered as a metal part in the housing part by attaching the metal member 601 in which the slot 602 is formed.

  In the present embodiment, the metal member 601 in which the slot 602 is formed and the IC chip 603 constitute a label-like RFID tag (attached RFID tag) 600 that is attached to the housing unit 120. The RFID tag 600 is a flat-type slot antenna. For example, a slot 602 is formed in a metal member 601 made of aluminum foil, and an IC chip 603 is electrically joined thereto with a conductive agent or the like, and an adhesive, Label with an adhesive to make an antenna label. Since the metal member 601 is formed with a slot 602, it can also be called a slot substrate or an antenna substrate.

  The metal member 601 of the RFID tag 600 serving as the antenna label is attached to the non-metallic container 120. In this embodiment, since the metal member 601 is affixed to at least the side wall surface of the non-metallic housing part 120, the slot 602 formed in the metal member 601 communicates with the inner side surface of the side wall of the non-metallic housing part 120. do not do.

  As an example of the dimensions of the RFID tag 600, in the horizontal antenna shown in FIGS. 5A to 5C, the metal member 601 has a horizontal length of 216 mm × a vertical length of 104 mm and a thickness of 13 μm, and the slot 602 is horizontal. The length in the direction (Ly): 188 mm × the length in the vertical direction (Lx): 4 mm. 5D, the metal member 601 has a horizontal length of 104 mm × vertical length of 216 mm and a thickness of 13 μm, and the slot 602 has a horizontal length of 4 mm × vertical length: 188 mm.

  In the present embodiment, for example, Impinj Monza 3 manufactured by Avery Dennison is used as the IC chip.

  As a position for attaching the RFID tag 600, when used for measuring the liquid level, it is provided on the side wall as shown in FIG. 5 (a) or FIG. 5 (d). In addition, it may be provided in the upper part as shown in FIG. 5B for use in confirming that the liquid is full, and may be provided in the lower part as shown in FIG. In the present embodiment, four RFID tags 600 are affixed as antenna labels. However, the number of RFID tags 600 may be the same as that shown in FIG. It is sufficient to attach it to at least the side wall as in d).

  The RFID tag 600, which is a slot antenna installed in this way, communicates with the RFID reader / writer 200, which is an external transmission / reception unit, with an intensity corresponding to the liquid level position of the storage unit 110. Specifically, the RFID tag 600 replies (transmits) a radio wave of 920 to 950 MHz transmitted from the RFID reader / writer 200 (see FIG. 1, IU-9061 manufactured by Mars or V750 manufactured by OMRON). The amount of liquid is detected based on the communication situation in which the strength changes according to the amount of liquid. As a premise, the container 100 in which any RFID tag 600 of FIGS. 5A to 5D is installed is installed in an effective communication area that is a space area capable of communicating with the RFID reader / writer 200 outside the container. ing.

  As shown in FIGS. 6 (c) and 7 (c), the RFID reader / writer 200 has a response strength of radio waves from the RFID tag 600 installed on the side wall according to the amount of liquid in the container. The liquid level is deciphered by utilizing the fact that the communication characteristics (communication sensitivity) change corresponding to the strength of the response.

  Specifically, in the RFID tag 600 constituting the slot antenna, if there is liquid up to the lower half in the width direction of the slot 602, the returned radio wave is absorbed by the liquid and the communication sensitivity is deteriorated (FIG. 5A). Alternatively, if there is a liquid up to about half of the extending direction of the slot 602 or slightly below half, the returned radio wave is absorbed by the liquid and the communication sensitivity is deteriorated (FIG. 5D).

  Therefore, the control means 300 and the valve 400 perform control based on the detection result of the liquid amount due to the change in communication sensitivity.

<About communication characteristics>
(Experiment 1)
Regarding specific communication characteristics, the communication characteristics of the antenna device according to the second embodiment described above were tested. In this experiment, detection was performed using an RFID label performance detection apparatus Tagformance lite (registered trademark) manufactured by Voyantic.

  Here, as Experiment 1, an example in which the RFID chip is arranged on the side wall of the container in the direction shown in FIG. 6A (the direction in which the slot extends in the horizontal direction, the sideways antenna) with the following dimensions will be described. To do.

  In this experiment, by comparing the liquid level position facing the RFID tag 600 with the central portion in the slot width direction, the liquid level position (height) in the container 100A is compared with the liquid level threshold value, and the liquid level is detected. Specifically, in the RFID tag, the liquid level height a from the lower surface of the metal member 601 is compared with the height b from the lower surface of the metal member 601 to the central portion in the width direction of the slot. Thereby, the liquid level height A from the bottom surface of the container in the entire container is compared with the liquid level threshold value Th1 associated with the center position B in the width direction of the slot from the bottom surface of the container, and the liquid level is compared. Detected.

  As a simulation condition when the characteristics of FIG. 6C are measured, the dimensions of each part of the antenna device shown in FIG. 6B are the same as those in FIG. 216 mm × vertical length 104 mm and thickness 13 μm, and the slot 602 has a horizontal length (Ly): 188 mm × vertical length (Lx): 4 mm.

  Therefore, the position b in the width direction of the slot 602 from the lower part of the metal member 601 made of aluminum foil used in this experiment is ½ of the vertical length 104 mm of the metal member 601 of the RFID tag 600. (B = 52 mm).

  FIG. 6C is a characteristic diagram showing the relationship between the liquid level position of the liquid and the communication distance when an experiment is performed using the RFID tag (slot sideways) which is the slot antenna of FIG. 6B. In the graph of FIG. 6C, the horizontal axis indicates the frequency (MHz), and the vertical axis indicates the theoretical forward reading range, that is, the communication performance (communication distance: m). From this graph, the change in communication performance when the liquid level was changed from 0 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm from the lower part of the metal member 601 as the slot substrate was measured. The read range of the RFID reader / writer can be read from the graph of each frequency shown in the figure.

  In FIG. 6C, when the liquid level is raised, a communication distance of 2 m or more can be secured if the distance from the lower surface of the label is 50 mm, which is lower than the position b in the central portion in the slot width direction. On the other hand, when the liquid level height a is 60 mm exceeding the central portion of the slot, the communication distance is 1 m or less (the condition of 60 mm is n = 2).

  Thus, when the minimum output of the RFID reader / writer required when reading the ID of the RFID tag with the RFID reader / writer is constant, the communication distance between the RFID tag and the RFID reader / writer is the liquid level. It changed abruptly across the position threshold Th1. In FIG. 6C, the communication distance can be distinguished from the upper data group and the lower data group at 920 MHz with a boundary of about 1.5 m.

  Accordingly, when the RFID reader / writer 200 is used at the output level used in this experiment, it is preferable that the distance between the container 100A in which the RFID tag is installed and the RFID reader / writer 200 is 1.5 to 2 m.

  It can also be seen that the communication distance sharply decreases when the height of the liquid level changes across the center of the slot. The liquid level can be accurately detected by rapidly changing the communication distance.

  Using this property, when a specific liquid level threshold is detected using the RFID tag 600 including a lateral antenna, the liquid level height (liquid level threshold) Th1 to be detected and the center position in the width direction of the slot 602 are detected. It is preferable to install them so that B is coincident or close. Furthermore, it is more preferable to install the central part of the IC chip 603 at a place where the communication sensitivity changes.

(Experiment 2)
Further, using the same detection device, the RFID tag is arranged on the side wall of the container in the direction shown in FIG. 7A (the direction in which the slot extends in the vertical direction, the vertical antenna) with the following dimensions. The characteristics of the example will be described.

  In this experiment, by comparing the liquid level position facing the RFID tag 600 and the central portion in the slot extending direction, the liquid level position (height) in the container 100A is compared with the liquid level threshold value, and the liquid level is detected. Specifically, in the RFID tag, the liquid level height a from the lower surface of the metal member 601 is compared with the height b from the lower surface of the metal member 601 to the center position in the extending direction of the slot. Thus, the liquid level height A from the bottom surface of the container in the entire container is compared with the liquid level threshold Th2 associated with the position B near the center in the extending direction of the slot from the bottom surface of the container. Is detected.

  The dimensions of each part shown in FIGS. 7A and 7B of the simulation conditions when the characteristics of FIG. 7C are measured are the same as those in FIG. 5D in that the metal member 601 has a horizontal length. 104 mm × vertical length 216 mm, thickness 13 μm, and slot 602 has horizontal length: 4 mm × vertical length: 188 mm. Therefore, the height b from the lower part of the metal member 601 made of aluminum foil to the center part in the slot width direction used in this experiment is 108 mm because it is ½ of the vertical length (216 mm) of the antenna label. (B = 108 mm).

  FIG. 7C is a characteristic diagram showing the relationship between the liquid level position of the liquid and the communication distance when an experiment is performed using the RFID tag (vertical direction) which is the slot antenna of FIG. 7B. In the graph of FIG. 7C, the horizontal axis indicates the frequency (MHz), and the vertical axis indicates the theoretical forward reading range. From this graph, the change in communication performance when the height of the liquid level was changed to 30 mm, 40 mm, 80 mm, and 120 mm from the lower part of the metal member 601 was measured. The read range of the RFID reader / writer can be read from the graph of each frequency shown in the figure.

  Also in this experiment, when the minimum output of the reader / writer required when reading the ID of the RFID tag with the RFID reader / writer is constant, the communication distance between the RFID tag and the reader / writer is the threshold of the liquid level position. It changed abruptly across Th2. Specifically, in FIG. 7C, when the liquid level is raised, a communication distance of 3 m or more can be secured up to 40 mm. On the other hand, when the surface height a is 80 mm, the communication distance becomes 2 m or less at a stretch.

  For example, in FIG. 6C, the communication distance can be distinguished from the upper data group and the lower data group in 920 MHZ with a boundary of about 2.5 m. Accordingly, when the RFID reader / writer 200 is used at the output level used in this experiment, it is preferable that the distance between the container 100A in which the RFID tag is installed and the RFID reader / writer 200 is set to 2.5 to 3 m.

  In this configuration example, it can be seen that the communication distance sharply decreases across about 80 mm in the vicinity of (about a little lower) 108 mm at the position b at the center in the extending direction of the slot. Using this property, in order to detect a specific liquid level threshold with the RFID tag 600 composed of the vertical antenna, the height (liquid level threshold) Th2 of the liquid level to be detected is determined in the extending direction of the slot 602. It is preferable to install so as to be close to (or less than) the position B at the center. Further, it is more preferable to install the central portion of the IC chip 603 at a place where the communication sensitivity changes.

  In the present embodiment, the same effects as in the first embodiment are obtained. Furthermore, since the RFID tag of Embodiment 2 can be attached to and detached from the container by pasting, it can be added later to the existing container.

  In the present embodiment, the same effects as in the first embodiment are obtained. Furthermore, since the RFID tag of Embodiment 2 can be attached to and detached from the container by pasting, it can be added later to the existing container.

<< Embodiment 3 >>
FIG. 8 is a schematic diagram of an RFID tag and a container provided with a plurality of the RFID tags according to the third embodiment. In the first and second embodiments, one RFID tag is installed on the side wall of the container. However, a plurality of RFID tags may be installed on the side wall.

  In the present embodiment, the pasted RFID tag 600 (see FIG. 5) which is the slot antenna used in the second embodiment is used. Since the dimensions, materials, characteristics, etc. are the same, the description is omitted.

  In this embodiment, two or more RFID tags 600 are attached to the side wall. As an example, in FIG. 8, three sheets are stuck side by side in the vertical direction.

  As the positions H, M, and L for attaching the RFID tag 600, the positions may be provided above and below a necessary area of the side wall, provided at the upper part, or provided at the lower part. Also in this embodiment, a plurality of RFID tags 600, which are installed slot antennas, return 920 to 950 MHz radio waves supplied from the RFID reader / writer 200 (see FIG. 1). Determine the amount of liquid.

  Then, based on the detection result of the amount of liquid due to the change in communication sensitivity between the RFID tag 600 and the RFID reader / writer 200, control is performed by the control means 300 and the valve 400 (see FIG. 1). For example, the detection liquid level corresponding to the central portion of the slot width of the RFID tag 600 provided near the top surface (H) corresponds to the supply stop level and the central portion of the slot width of the RFID tag 600 provided near the bottom surface (L). The detection liquid level is set as the supply start level. With this setting, the valve 400 can automatically stop supplying the liquid when the amount of liquid in the container reaches the supply stop level (H) by supplying the liquid. On the other hand, when the amount of liquid in the container decreases to the supply start level (L) due to the use of the liquid, the valve 400 can automatically start supplying the liquid.

  Alternatively, the RFID tag 600 attached to the center part (M) is set as a detection position, and when the liquid reaches the position B, the supply of the liquid is started or stopped, or the supply amount of the liquid is increased or decreased. You may adjust so that the kind of liquid may be changed depending on the case.

  Further, in the embodiment of FIG. 8, since three RFID tags are provided, the liquid surface position interpretation unit 301 is more reliably configured based on communication information (communication strength) received from a plurality of RFID tags. The surface position may be determined.

<< Embodiment 4 >>
FIG. 9 is a schematic view of an RFID tag according to Embodiment 9 and a container in which the RFID tag is variably provided. In this embodiment, the pasted RFID tag 600 (see FIG. 5) that is the slot antenna used in the second embodiment is used. Since the dimensions, materials, characteristics, etc. are the same, the description is omitted.

  In this embodiment, the RFID tag 600 is variably attached to the side wall, and the position is changed as necessary to grasp the actual liquid level.

  Also in this embodiment, a plurality of installed RFID tags RFID tag 600 returns a radio wave supplied from RFID reader / writer 200 (see FIG. 1) at 920 to 950 MHz, and RFID reader / writer 200 receives it. Then, the amount of liquid is determined.

  Then, based on the detection result of the amount of liquid due to the change in communication sensitivity between the RFID tag 600 and the RFID reader / writer 200, control is performed by the control means 300 and the valve 400 (see FIG. 1).

  For example, the liquid supply start level and the liquid supply stop level for the amount of liquid in the container are set in advance, and the RFID tag 600 can be moved together so that the side wall of the container coincides with the liquid level vertically. it can. In this case, when the center position in the width direction of the slot 602 of the RFID tag 600 corresponding to the liquid level rises to the liquid supply stop position (H), the valve 400 automatically stops the liquid supply. On the other hand, when the center in the width direction of the slot 602 of the RFID tag 600 is lowered to the liquid supply start position (L), the valve 400 can automatically start liquid supply.

  Alternatively, the central portion (M) may be set as a detection position, and when the liquid reaches the position B, the liquid supply may be adjusted to start or stop, or to increase or decrease the liquid supply amount. .

<< Embodiment 5 >>
In the experiment using the above-described embodiment, when a plurality of embodiments of the present invention are used, the liquid level is changed due to a significant change in the communication sensitivity between the RFID tag 600 and the RFID reader / writer 200 in the frequency band of 920 to 950 MHz. The height was detected.

  Here, in the UHF band, the frequency band assigned to the RFID differs from country to country. In consideration of using a product across multiple countries, it is preferable that an RFID frequency corresponding to each country can be used.

  In Japan, 915.8 to 923.5 MHz is used as the RFID frequency band, and 952 to 957.6 MHz is used after 2018. The RFID frequency band is, for example, 902 to 926 MHz in the United States, 920.5 to 924.5 MHz in China, and 908.5 to 914 MHz in Korea, and is close to the frequency band in Japan. Therefore, as can be seen from FIG. 5 (c) of the experimental graph, in these bands, the communication distance changes abruptly at a predetermined threshold with the same communication performance as 920 MHz, so that the amount of liquid in the container is detected. As described above, communication can be performed using the RFID chip.

  However, the RFID frequency band is 865 to 868 MHz in Europe, but referring to the graph of FIG. 5C, the communication performance around 865 MHz is not significantly different from other values around the threshold value. It is difficult to detect the liquid level.

  Therefore, an RFID tag having antenna performance that enables the communication performance to change abruptly near a desired liquid level threshold even when the frequency to be used is changed is applied as an embodiment of the present invention.

  10A is an enlarged view of the IC chip module of the slot antenna according to the fifth embodiment, FIG. 10B is a cross-sectional view of the IC chip module of FIG. 10A, and FIG. It is the block diagram in which the IC chip module of Fig.10 (a) was attached to the container.

  In the present embodiment, an IC chip module 510 including an IC chip 511 can be attached to the slot 501 of the metal portion (a metal housing portion in the present embodiment) as the frequency variable RFID tag 500A.

  More specifically, the IC chip module 510 includes an IC chip 511 and two terminal members 520 as shown in FIG. 10A as an example.

  Each terminal member 520 has a metal foil (here, an aluminum foil) 521 and a resin film 522 that laminates both surfaces of the metal foil 521. The resin film 522 has a role as an insulating member between the metal plate P and the metal foil 521 and has a role to protect the metal foil 521 from contamination and breakage.

  As an example, the metal foil 521 of each terminal member 520 is connected to the electrode 512 of the IC chip 511 as shown in FIG.

  Similar to the first embodiment, the IC chip module 510 having such a configuration is attached to a slot 501 that is an elongated slit (cut) or groove provided in a metal container as shown in FIG.

  In short, in the IC chip module 510, the two conductive members (metal foils) 521 are insulated from the outer surface of the metal part (metal housing part 110) on one side and the other side of the slot 501 in the width direction of the slot 501. It is attached via a member (resin film 522). The IC chip 511 is supplied with power via two conductive members (metal foils) 521.

  Here, the communicable distance between the RFID tag 500A and the external reader / writer 200 is the size of the metal foil 521 in the terminal member 520 and the protective film interposed between the metal plate (metal container 110). And the thickness of an insulator such as an adhesive layer. That is, by adjusting the size of the metal foil 521 in accordance with the thickness of the insulator, the impedance in electrostatic coupling can be reduced and the communicable distance can be extended.

Here, the frequency of the radio wave used for communication is f, the electromotive force generated between one side and the other side of the slot (slit or groove) 501 when receiving the radio wave is Wa, the voltage is V, The area of each of the members 521 is S, the thickness of the insulating member 522 is d, the dielectric constant of the insulating member 522 is ε _r , the dielectric constant of vacuum is ε ₀ , and the minimum value of electric power required for the operation of the IC chip 511 is Wmin. Then, the IC chip module 510 in the RFID tag 500A is
Wmin ≦ Wa-4πf · S · ε ₀ · ε _r · V ² / d (1)
(See JP 2013-140575 A).

For example, when f = 950 MHz, the insulator is PET (polyethylene terephthalate), d = 20 μm, and the desired communication distance is 3 m, if S = 100 mm ² , the relationship of the above formula (1) can be satisfied. it can.

  By adjusting the IC chip module to the slot 501 that is a slit or groove with an adhesive (tape), an adhesive, a screw, a clip, etc., the sensitivity can be adjusted depending on the liquid and the material of the container. Like that. For example, in this embodiment, the IC chip position is 20 mm with a stainless steel container.

  Depending on the communication status returned from the RFID tag 500A including the adjusted IC chip module 510, an RFID reader / writer (IU-9061 manufactured by Mars or V750 manufactured by OMRON) is used in 920 to 950 MHz and other frequency bands in the UHF band. Etc.) is read the amount of liquid.

  In this embodiment, the IC chip module 510 is described as the integrated RFID tag of the first embodiment. However, the IC chip module 510 can also be adopted in the pasted RFID tag of the second embodiment. Specifically, an IC chip module 510 including an IC chip 511 can be attached to a slot 602 of a metal part (a metal member in the second embodiment) 601. By using the IC chip module 510, it is possible to adjust the sensitivity so that the frequency of the communication of the attached RFID tag is variable.

  In this embodiment, control is performed by the control means 300 and the valve 400 based on the detection result of the amount of liquid due to the change in communication sensitivity between the RFID tag 500A and the RFID reader / writer 200 whose communication frequency is adjusted to the frequency for each country. Do.

  Also in this embodiment, there exists an effect similar to the above-mentioned embodiment. Furthermore, in this embodiment, since the frequency band in which RFID can be communicated can be changed while maintaining the threshold characteristic, this management system can be used in a plurality of countries.

<< Embodiment 6 >>
FIG. 11A is a schematic view of a container provided with an RFID tag and covered with a cover, and FIG. 11B is a schematic view of a container provided with an RFID tag and wrapped in a bag.

  In the containers 100E and 100F of the present embodiment, the liquid level of the container may be managed by covering, for example, a resin cover with respect to the metal container 110 provided with the integrated RFID 500 as in the first embodiment. . Alternatively, as shown in FIG. 11B, the liquid level may be managed in a state where the container is wrapped in a bag. In this case, it is preferable that a cover or a bag is opened at a portion corresponding to the slot 501 and the IC chip 502 which are radio wave communication portions of the RFID tag so as not to interrupt the communication.

  In the present embodiment, even if the metal container 110 is covered with a resin cover or bag in order to enhance safety, the same effect as that of the first embodiment can be obtained.

  Further, as a container used in a plurality of embodiments of the present invention, an airtight container such as an ink jet ink tank or a battery tank can be applied. By utilizing any one of the embodiments of the present invention, it is possible to easily detect the remaining amount of ink and battery electrolyte and to manage the amount of liquid in these configurations.

<Piping>
Although the container is used as the above-described embodiment, the RFID tags 500, 600, and 500A according to the embodiment of the present invention may be employed in the piping. 12A and 12C show an example of a pipe 700 provided with the RFID tag 500 or 500A of the first or fifth embodiment described above. FIGS. 12B and 12D show an example of 700A provided with the RFID tag 600 of the second embodiment.

  Note that FIG. 12 shows an example in which one RFID tag is arranged. However, in FIGS. 12A to 12D, the RFID tags 500, 500A, and 600 are arranged on the side wall surface of the pipe as in the third embodiment. A plurality of them may be provided. Alternatively, with respect to FIGS. 12B and 12D, the RFID tag 600 may be arranged so as to be movable with respect to the side wall surface as in the fourth embodiment.

  When the RFID tag according to the embodiment of the present invention is used for piping as in this configuration example, the same effect as the configuration using the container is obtained.

<Slit modification>
In the embodiment of the present invention described above, the slit (or groove, slot) has a linear shape. However, the shape of the slit is not limited to a straight line, and the area of the slit is equal in the vertical direction across the center of the IC chip. The shape of the slit may be changed within a range that satisfies the above. For example, the slit may be bent one or more times at various angles including a right angle. Here, in order to make the slit area equal across the center of the IC chip, when bending at the IC chip installation position, bend an odd number of times, and when bending at a position different from the IC chip installation position, It is preferable to bend even times.

  Furthermore, as a modification of the shape, the slits may be branched (including a T-shaped branch) or crossed. In addition, the slit may be curved, and the slit may be bent or bent a plurality of times, thereby forming an angular ring shape or an annular shape. Alternatively, it is also possible to form a part of the slit into a square ring shape and an annular shape and combine these rings.

  Similarly to the above-described embodiment, the slit may have a portion extending in the direction of gravity and / or a portion extending in the horizontal direction. In addition, / or the slit may have a portion that extends with an inclination with respect to the gravity direction and the horizontal direction.

  Here, when the slit is deformed, the slit area is equal in the vertical direction across the central part of the IC chip in a normal state in consideration of the location where the container is disposed sideways or the piping is disposed. In addition, even when rotated 90 degrees to the left and right, it is more preferable that the slit area is equal in the vertical direction across the center of the IC chip. For example, it is preferable to have point symmetry with respect to the center of the IC chip as an axis, or line symmetry with respect to the horizontal plane passing through the center of the IC chip.

  Even when the slot antenna using the deformed slit is installed, the slit is arranged so that the central part of the IC chip is close to the liquid level threshold value to be detected in the housing part. With this arrangement, the RFID reader / writer 200 changes the intensity of communication from the RFID tag according to the comparison between the center part of the slit (the center part of the IC chip) and the actual liquid level in the container. The comparison result between the surface and the liquid level threshold can be detected.

  The “container” in the claims of the present invention may also include piping as shown in FIG. Further, in the above description of the present invention, “sealing” may include not only tight sealing so that there is no gap, but also opening that allows liquid supply.

  The invention is not limited by the embodiments described above and the accompanying drawings, but is defined by the appended claims. Accordingly, within the scope of the technical idea of the present invention described in the claims, a person having ordinary knowledge in the technical field can make various forms of substitutions, modifications and changes. These are also within the scope of the present invention.

100, 100A, 100B, 100C, 100D, 100E, 100F Container 110 Metal housing (housing)
120 Resin housing (housing)
200 RFID reader / writer (reader / writer)
301 Liquid level position interpretation unit (control means)
302 Calculation setting unit (control means)
303 Valve adjustment part (control means)
400 Valve (Adjustment means)
500,500A RFID tag (integrated RFID tag, slot antenna)
501 Slit or groove (slot)
502 IC chip 510 IC chip module 511 IC chip 512 Electrode 520 Terminal member 521 Metal foil (conductive member)
522 Resin film (insulating material)
600 RFID tags (attached RFID tags, slot antennas)
601 Metal foil (antenna label)
602 Slit or groove (slot)
603 IC chip 700 Piping 1000 Liquid level adjustment system A Liquid level in liquid container (liquid level height, liquid level position)
B Slot central portion in container a Liquid level height in RFID tag b Slot central portion Th1, Th2 in RFID tag Liquid level threshold

JP 09-330130 A Japanese Patent No. 3171523 Japanese Patent No. 3676245

Claims (11)

A container that can communicate with an external transceiver,
A receiving portion that contains a liquid and is provided with a metal portion in which a slot is formed at least on the outer side surface of the side wall; and the slot does not communicate with the inner side surface of the side wall;
An RFID chip is attached to the slot of the metal part of the housing part, is formed of the slot and the IC chip, and communicates with the external transceiver unit with strength according to the liquid surface position in the housing part; Having
container. As the metal part, a part of the outer surface of the side wall of the housing portion is covered by attaching a metal member in which the slot is formed,
The IC chip is electrically joined and attached to the slot of the metal member,
The metal member in which the slot is formed and the IC chip are RFID tags that can be attached to the housing portion.
The container according to claim 1. The metal member of the RFID tag is attached to the housing part so as to be movable.
The container according to claim 2. As the metal part, at least the side wall of the housing portion is a metal container, and the slot is directly formed on the outer surface of the side wall of the metal container,
The IC chip is electrically joined and attached to the slot of the metal container,
The slot and the IC chip are RFID tags formed integrally with the housing portion.
The container according to claim 1. In the RFID tag, an IC chip module including the IC chip can be attached to the slot of the metal part,
The IC chip module includes two conductive members that are respectively attached to outer surfaces of the metal portions on one side and the other side of the slot with respect to the width direction of the slot via insulating members. The IC chip is supplied with power through the two conductive members,
In the IC chip module, the frequency of the radio wave used for communication is f, the electromotive force generated between one side and the other side of the slot when receiving the radio wave is Wa and the voltage is V, and the two conductive members are respectively , S, the insulating member thickness d, the insulating member dielectric constant ε _r , the vacuum dielectric constant ε ₀ , and the minimum power Wmin required for the operation of the IC chip,
The relationship of “Wmin ≦ Wa−4πf · S · ε ₀ · ε _r · V ² / d” is satisfied,
The container according to claim 1. Arranging a plurality of the RFID tags in the housing part,
The container according to any one of claims 1 to 5. The IC chip is variably attached to the slot.
The container according to any one of claims 1 to 6. A metal portion containing liquid and having a slot formed at least on an outer surface of the side wall, wherein the slot does not communicate with the inner side surface of the side wall; and the slot of the metal portion of the housing portion Or an IC tag attached to the groove, formed of the slot and the IC chip, and having an RFID tag that communicates with an external transmitting / receiving unit with strength according to the liquid level position in the housing unit;
An RFID reader / writer that reads the position of the liquid surface of the container in the container based on the intensity of communication by communicating radio waves with the RFID tag;
Control means for controlling the amount of liquid supplied to the storage part of the container according to the liquid amount read;
Adjusting means for adjusting the amount of liquid supplied to the container of the container so that the controlled amount of liquid is obtained,
Liquid volume management system. The adjusting means automatically supplies or stops liquid when the liquid in the container of the container reaches a predetermined amount.
The liquid amount management system according to claim 8. The control means controls the type of liquid to be supplied to the container of the container according to the read liquid amount,
The adjusting means supplies the controlled type of liquid into the container so as to have the controlled liquid amount.
The liquid quantity management system according to claim 8 or 9. A liquid amount management method for managing the amount of liquid in a container,
The container is provided with a metal portion that contains liquid and has a slot formed at least on the outer side surface of the side wall, and the slot does not communicate with the inner side surface of the side wall; An IC chip is attached to the slot, and the RFID tag is formed by the slot and the IC chip, and communicates with an external transmitting / receiving unit at a strength corresponding to a liquid surface position in the housing unit.
The step of reading the liquid level information based on the strength of communication by communicating radio waves with the RFID tag by the external transceiver unit;
Controlling the amount of liquid to be supplied to the container of the container according to the read liquid surface position;
Adjusting the amount of liquid supplied to the container of the container so that the controlled amount of liquid is obtained.
Liquid volume control method.

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