CN111723895A - Radio frequency tag - Google Patents
Radio frequency tag Download PDFInfo
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- CN111723895A CN111723895A CN202010089822.7A CN202010089822A CN111723895A CN 111723895 A CN111723895 A CN 111723895A CN 202010089822 A CN202010089822 A CN 202010089822A CN 111723895 A CN111723895 A CN 111723895A
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- 238000004891 communication Methods 0.000 claims description 69
- 238000000034 method Methods 0.000 description 24
- 230000008569 process Effects 0.000 description 24
- 238000010586 diagram Methods 0.000 description 6
- 230000004044 response Effects 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 230000004913 activation Effects 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 230000009471 action Effects 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000006641 stabilisation Effects 0.000 description 2
- 238000011105 stabilization Methods 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000004065 semiconductor Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
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Classifications
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
- G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
- G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
- G06K19/07745—Mounting details of integrated circuit chips
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
- G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
- G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
- G06K19/07749—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06K—GRAPHICAL DATA READING; PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS
- G06K19/00—Record carriers for use with machines and with at least a part designed to carry digital markings
- G06K19/06—Record carriers for use with machines and with at least a part designed to carry digital markings characterised by the kind of the digital marking, e.g. shape, nature, code
- G06K19/067—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components
- G06K19/07—Record carriers with conductive marks, printed circuits or semiconductor circuit elements, e.g. credit or identity cards also with resonating or responding marks without active components with integrated circuit chips
- G06K19/077—Constructional details, e.g. mounting of circuits in the carrier
- G06K19/07749—Constructional details, e.g. mounting of circuits in the carrier the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card
- G06K19/07773—Antenna details
- G06K19/07777—Antenna details the antenna being of the inductive type
- G06K19/07779—Antenna details the antenna being of the inductive type the inductive antenna being a coil
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/12—Supports; Mounting means
- H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
- H01Q1/2208—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems
- H01Q1/2225—Supports; Mounting means by structural association with other equipment or articles associated with components used in interrogation type services, i.e. in systems for information exchange between an interrogator/reader and a tag/transponder, e.g. in Radio Frequency Identification [RFID] systems used in active tags, i.e. provided with its own power source or in passive tags, i.e. deriving power from RF signal
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
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- Engineering & Computer Science (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Theoretical Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Near-Field Transmission Systems (AREA)
Abstract
The invention realizes an RF tag capable of stably communicating. An RF tag (1) comprises: an antenna coil (20); an antenna coil (30) disposed so as to face the antenna coil (20); and a switch (40) that switches between a first state in which the antenna coil (30) is connected so as to be counter-wound with respect to the antenna coil (20) and a second state in which the antenna coil (30) is not counter-wound with respect to the antenna coil (20).
Description
Technical Field
The present invention relates to a Radio Frequency (RF) tag (tag).
Background
Radio Frequency Identification (RFID) technology is a technology for wirelessly communicating with an RF tag (also referred to as an RFID tag) by a reader/writer, reading information of the RF tag, and writing information into the RF tag.
RFID technology is used in various industrial fields, and reader/writers and RF tags having various configurations have been developed (patent documents 1 to 3). The electromotive force of these RF tags is supplied by a magnetic field generated by a reader/writer.
[ Prior art documents ]
[ patent document ]
Patent document 1: japanese patent laid-open publication No. 2011-87025
Patent document 2: japanese patent laid-open No. 2009-94681
Patent document 3: japanese patent laid-open publication No. 2017-204036
Disclosure of Invention
[ problems to be solved by the invention ]
However, in the conventional technology described above, since the magnetic flux from the reader/writer becomes sparse at a position distant from the reader/writer, a sufficient electromotive force cannot be supplied to the RF tag. Therefore, if the RF tag is at a position where it is difficult to supply power, it is difficult to perform communication stably.
An object of one embodiment of the present invention is to provide an RF tag capable of performing stable communication.
[ means for solving problems ]
In order to solve the problem, an RF tag according to an aspect of the present invention includes: a first antenna coil; a second antenna coil disposed to face the first antenna coil; and a switch that switches between a first state in which the second antenna coil is connected to the first antenna coil in such a manner that the second antenna coil is reversely wound with respect to the first antenna coil and a second state in which the second antenna coil is not reversely wound with respect to the first antenna coil.
According to the above configuration, since the second antenna coil is connected so as to be wound around the first antenna coil in the first state, the electromotive force generated in the entire antenna coil is a difference between the electromotive force generated in the first antenna coil and the electromotive force generated in the second antenna coil.
Further, since the first antenna coil and the second antenna coil are disposed so as to face each other, a distance from the reader/writer to the first antenna coil is different from a distance from the reader/writer to the second antenna coil in use. Since the degree of change in the magnetic field due to the distance from the reader/writer is large in the vicinity of the reader/writer and small in the far direction, the difference between the electromotive force generated in the first antenna coil and the electromotive force generated in the second antenna coil is also large in the vicinity of the reader/writer and small in the far direction of the reader/writer. Therefore, the electromotive force generated in the entire antenna coil in the first state serves as an index of the distance from the reader/writer.
In the second state, the second antenna coil is not reversely wound with respect to the first antenna coil, and therefore the RF tag can obtain an electromotive force larger than that in the first state.
As described above, communication can be performed stably by switching to the second state according to the electromotive force obtained in the first state and performing communication.
In one embodiment, the RF tag includes: and a control unit that switches the switch, wherein the control unit switches the switch to a second state when the control unit operates normally in the first state using electromotive force generated by the first antenna coil and the second antenna coil as a power source.
With this configuration, the RF tag can be switched to the second state to perform communication at a position sufficiently close to the reader/writer where the control unit normally operates in the first state. This enables stable communication.
In one embodiment, the second state is a state in which the second antenna coil is blocked with respect to the first antenna coil.
According to the above configuration, the electromotive force obtained in the first state becomes a difference between the electromotive force generated in the first antenna coil and the electromotive force generated in the second antenna coil, and the electromotive force obtained in the second state becomes the electromotive force generated in the first antenna coil or the electromotive force generated in the second antenna coil, so that the RF tag can obtain an electromotive force larger than that in the first state in the second state.
In one embodiment, the second state is a state in which the second antenna coil is wound in the forward direction with respect to the first antenna coil.
According to the above configuration, the electromotive force obtained in the first state is a difference between the electromotive force generated in the first antenna coil and the electromotive force generated in the second antenna coil, and the electromotive force obtained in the second state is a sum of the electromotive force generated in the first antenna coil and the electromotive force generated in the second antenna coil, so that the RF tag can obtain an electromotive force larger than that in the first state.
An RF tag according to another aspect of the present invention includes: a first antenna coil; a second antenna coil disposed to face the first antenna coil; and a control unit that inputs an electromotive force VA of the first antenna coil and an electromotive force VB of the second antenna coil, and communicates with a reader/writer using at least the electromotive force VA of the first antenna coil as a power supply when VA-VB is equal to or greater than a predetermined value.
According to the above configuration, since the first antenna coil and the second antenna coil are disposed so as to face each other, a distance from the reader/writer to the first antenna coil is different from a distance from the reader/writer to the second antenna coil in use. Since the degree of change in the magnetic field due to the distance from the reader/writer is large in the vicinity of the reader/writer and small in the distance, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil is also large in the vicinity of the reader/writer and small in the distance from the reader/writer. Therefore, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil becomes an index of the distance from the reader/writer.
As described above, when the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil is equal to or greater than the predetermined value, communication with the reader/writer is performed using at least the electromotive force of the first antenna coil as a power supply, whereby stable communication can be performed.
In one embodiment, the control unit communicates with a reader/writer using an electromotive force VA of the first antenna coil and an electromotive force VB of the second antenna coil as power supplies when VA-VB is equal to or greater than a predetermined value.
According to the above configuration, communication can be stably performed by using the electromotive force of the first antenna coil and the electromotive force of the second antenna coil as power sources.
In one embodiment, the first antenna coil is disposed on a reader/writer side to be communicated with, as compared with the second antenna coil.
According to this configuration, communication can be performed stably by performing communication with the reader/writer using the electromotive force of at least the first antenna coil as a power source.
In one embodiment, an inner circumference of the second antenna coil is smaller than an inner circumference of the first antenna coil.
According to this configuration, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be increased without increasing the distance between the first antenna coil and the second antenna coil. Thus, the operation accuracy corresponding to the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be improved without increasing the size of the RF tag.
In one embodiment, the axis of the first antenna coil coincides with the axis of the second antenna coil.
According to this configuration, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can accurately represent the distance from the reader/writer. This improves the operation accuracy according to the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil.
In one embodiment, the number of turns of the first antenna coil is greater than the number of turns of the second antenna coil.
According to this configuration, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be increased without increasing the distance between the first antenna coil and the second antenna coil. Thus, the operation accuracy corresponding to the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be improved without increasing the size of the RF tag.
In addition, the "RF tag" in the present specification generally refers to an information medium for reading and writing information stored in a built-in memory in a non-contact manner using electromagnetic waves. A tag communication device (reader/writer) is used for reading and writing information of the RF tag. RF tags are sometimes referred to as "RFID tags", "electronic tags", "IC tags", "wireless tags", and the like. The RF tag in this specification includes both passive tags (passive tags) and active tags (active tags), and also includes a contactless Integrated Circuit (IC) card (card) that is mainly carried by a person.
[ Effect of the invention ]
According to an aspect of the present invention, an RF tag capable of stably performing communication can be realized.
Drawings
Fig. 1 is a block diagram showing a configuration example of a main part of an RF tag according to embodiment 1 of the present invention.
Fig. 2 is a diagram illustrating an operation principle of the RF tag according to embodiment 1 of the present invention.
Fig. 3 is a flowchart showing an example of processing of the RF tag according to embodiment 1 of the present invention.
Fig. 4 is a block diagram showing a configuration example of a main part of an RF tag according to embodiment 2 of the present invention.
Fig. 5 is a flowchart showing an example of processing of the RF tag according to embodiment 2 of the present invention.
Fig. 6 is a flowchart showing an example of processing of the RF tag according to embodiment 3 of the present invention.
[ description of symbols ]
1. 5: RF tag
2: read-write machine
20. 30: antenna coil
40: switch with a switch body
70: main control part
71. 72: RF section
73. 74: communication control part
75: determination unit
76: addition unit
77: comparator with a comparator circuit
78: storage unit
Detailed Description
Hereinafter, an embodiment (hereinafter, also referred to as "the present embodiment") according to one aspect of the present invention will be described with reference to the drawings.
[ embodiment mode 1 ]
Application example § 1
Fig. 1 is a block diagram showing a configuration example of a main part of an RF tag 1 according to the present embodiment. Fig. 2 is a diagram illustrating the operation principle of the RF tag 1. An example of a scenario to which the present invention is applied will be described with reference to fig. 1 and 2. The RF tag 1 includes an antenna coil (first antenna coil) 20, an antenna coil (second antenna coil) 30, and a switch 40.
The antenna coil 20 and the antenna coil 30 generate electromotive forces by magnetic fields generated by the reader/writer 2.
Since the antenna coil 30 is disposed to face the antenna coil 20, a distance from the reader/writer 2 to the antenna coil 20 is different from a distance from the reader/writer 2 to the antenna coil 30 in use. In one embodiment, as shown in fig. 2, the antenna coil 20 is spaced apart from the antenna coil 30 by a distance d.
As shown in the lower graph of fig. 2, generally, the magnetic field becomes weaker as the distance from the reader/writer 2 becomes longer, and thus a difference in electromotive force occurs between two antenna coils having different distances from the reader/writer 2. For example, when a magnetic field HA1 is applied to antenna coil 20 of RF tag 1 located at position a and a magnetic field HB1 is applied to antenna coil 30, HA1 > HB1 causes the electromotive force generated in antenna coil 20 to be greater than the electromotive force generated in antenna coil 30.
As shown in the graph, the degree of change in the magnetic field due to the distance from the reader/writer 2 is generally large in the vicinity of the reader/writer 2 (for example, a position a) and small in the distant place (for example, a position B). Therefore, the difference between the electromotive force generated in the antenna coil 20 and the electromotive force generated in the antenna coil 30 is also large in the vicinity of the reader/writer 2 (for example, a position a) and small in the distance from the reader/writer 2 (for example, a position B). For example, when magnetic field HA2 is applied to antenna coil 20 of RF tag 1 located at position B and magnetic field HB2 is applied to antenna coil 30, HA1-HB1 > HA2-HB2, the difference between the electromotive force generated in antenna coil 20 of RF tag 1 located at position a and the electromotive force generated in antenna coil 30 > the difference between the electromotive force generated in antenna coil 20 of RF tag 1 located at position B and the electromotive force generated in antenna coil 30.
Here, the switch 40 switches between a first state in which the antenna coil 30 is connected to the antenna coil 20 so that the antenna coil 30 is reversely wound with respect to the antenna coil 20, and a second state in which the antenna coil 30 is not reversely wound with respect to the antenna coil 20. The second state may be a state in which the antenna coil 30 is blocked with respect to the antenna coil 20, or a state in which the antenna coil 30 is wound in the forward direction with respect to the antenna coil 20 and connected.
In the first state, since the antenna coil 30 is connected so as to be counter-wound with respect to the antenna coil 20, the electromotive force generated in the entire antenna coil is a difference between the electromotive force generated in the antenna coil 20 and the electromotive force generated in the antenna coil 30. Therefore, the electromotive force generated in the entire antenna coil in the first state serves as an index of the distance from the reader/writer 2.
In the second state, the antenna coil 30 is not wound around the antenna coil 20, and therefore the RF tag 1 can obtain a larger electromotive force than in the first state.
The RF tag 1 can perform communication stably by switching to the second state and performing communication when the RF tag is sufficiently close to the reader/writer 2 based on the electromotive force generated in the antenna coil as a whole in the first state.
Construction example 2
[ example of hardware configuration of RF tag 1 ]
An example of the hardware configuration of the RF tag 1 will be described with reference to fig. 1 and 2. In the example of fig. 1, the RF tag 1 includes a main control unit (control unit) 70 in addition to the antenna coil 20, the antenna coil 30, and the switch 40. The main control unit 70 includes an RF unit 71 and a communication control unit 73.
In the first state, the switch 40 is connected so that the antenna coil 30 is wound around the antenna coil 20. Specifically, one of the wires of the antenna coil 20 is connected to the RF unit 71, and the other wire is connected to the antenna coil 30. One of the wires of the antenna coil 30 is connected to the antenna coil 20, and the other wire is connected to the RF unit 71. The antenna coil 30 is wound around the antenna coil 20.
In one embodiment, the switch 40 blocks the antenna coil 30 from the antenna coil 20 in the second state. Specifically, one of the wires of the antenna coil 20 is connected to the RF unit 71, and the other wire is also connected to the RF unit 71. The antenna coil 30 is not connected to any member.
At this time, the electromotive force obtained in the first state becomes a difference between the electromotive force generated in the antenna coil 20 and the electromotive force generated in the antenna coil 30, and the electromotive force obtained in the second state becomes the electromotive force generated in the antenna coil 20, so that the RF tag 1 can obtain an electromotive force larger than that in the first state in the second state. Further, the RF tag 1 communicates with a reader/writer using the antenna coil 20.
In another embodiment, the switch 40 connects the antenna coil 30 to the antenna coil 20 in the forward winding direction in the second state. Specifically, one of the wires of the antenna coil 20 is connected to the RF unit 71, and the other wire is connected to the antenna coil 30. One of the wires of the antenna coil 30 is connected to the antenna coil 20, and the other wire is connected to the RF unit 71. The antenna coil 30 is wound along the antenna coil 20.
At this time, the electromotive force obtained in the first state is a difference between the electromotive force generated in the antenna coil 20 and the electromotive force generated in the antenna coil 30, and the electromotive force obtained in the second state is a sum of the electromotive force generated in the antenna coil 20 and the electromotive force generated in the antenna coil 30, so that the RF tag 1 can obtain an electromotive force larger than that in the first state in the second state. The RF tag 1 communicates with a reader/writer using the antenna coil 20 and the antenna coil 30.
In the present embodiment, the antenna coil 20 is disposed on the reader/writer side as a communication target rather than the antenna coil 30. Therefore, in the second state, the electromotive force generated at least in the antenna coil 20 is used as a power source. In the case of the configuration in which the antenna coil 30 is disposed on the reader/writer side of the antenna coil 20, the electromotive force generated at least in the antenna coil 30 may be used as the power source in the second state.
In one embodiment, the axis 21 of the antenna coil 20 is coincident with the axis 31 of the antenna coil 30. Thus, the antenna coil 20 and the antenna coil 30 face each other at the same position with the same inclination with respect to the reader/writer, and the strength of the magnetic field passing through the antenna coil 20 and the antenna coil 30 changes in the same manner according to the distance from the reader/writer. Therefore, the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 indicates the distance from the reader/writer with high accuracy. This makes it possible to switch to the second state accurately based on the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 in the first state.
The switch 40 is controlled by the communication control unit 73 to switch between the first state and the second state. The switch 40 may be in the first state when no power is input, or in the second state when no power is input.
In one embodiment, the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 in the first state can be adjusted by appropriately selecting the inner periphery of each antenna coil, the number of turns, the material of the coil, and the material of the core (core). For example, in one embodiment, the inner circumference of the antenna coil 30 may be smaller than the inner circumference of the antenna coil 20. In one embodiment, the number of turns of the antenna coil 20 may be larger than the number of turns of the antenna coil 30. With this configuration, the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 in the first state can be increased without increasing the distance between the antenna coil 20 and the antenna coil 30. This can avoid an increase in size of the RF tag 1, and can switch to the second state accurately according to the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 in the first state.
The main control unit 70 integrally controls each unit of the RF tag 1. The RF unit 71 includes a known high-frequency circuit for realizing wireless communication using an antenna coil. The RF unit 71 may include one or more of a filter, an Analog/Digital (a/D) converter, a Digital/Analog (D/a) converter, a matching circuit, a tuner (tuner), a modulation/demodulation circuit, and the like. The communication control unit 73 generates a transmission signal and processes a reception signal, and controls the switch 40. When the main control unit 70 normally operates using the electromotive forces generated by the antenna coil 20 and the antenna coil 30 as a power source in the first state, the communication control unit 73 switches the switch 40 to the second state. In one embodiment, the normal operation of the main control unit 70 means that the main control unit 70 successfully receives a command transmitted from the reader/writer.
Action example 3
Fig. 3 is a flowchart showing an example of processing of the RF tag 1. An example of processing of the RF tag 1 will be described based on the flowchart of fig. 3. The process flow described below is merely an example, and each process may be changed as far as possible. In addition, the process flow described below can be appropriately omitted, replaced, and added according to the embodiment.
First, from a state where no electromotive force is supplied to the RF tag 1 and the RF tag 1 is not operated, an electromotive force is supplied to the RF tag 1 by a magnetic field generated by the reader/writer. In this case, the switch 40 may be in the first state or the second state. When the voltage of the generated electromotive force is higher than the starting voltage of the RF tag 1 (YES in S10), the RF tag 1 starts operating. On the other hand, if the voltage of the generated electromotive force is lower than the activation voltage of the RF tag 1 (NO in S10), the RF tag 1 is not activated sufficiently and cannot operate (S11), and the process ends.
When the RF tag 1 starts operating, the communication control unit 73 controls the switch 40 to be in the first state (S12). Thereby, the antenna coil 20 and the antenna coil 30 are connected in a counter-wound manner.
Then, the RF tag 1 waits for a command (inventory) to be transmitted from the reader/writer. When the command (list) is transmitted from the reader/writer, the communication control unit 73 performs a command (list) reception process (S13). When the RF tag 1 obtains sufficient electromotive force in the first state and the communication control unit 73 successfully performs the reception process of the command (list) (yes in S14), the communication control unit 73 regards that the main control unit 70 normally operates using the electromotive forces generated by the antenna coil 20 and the antenna coil 30 as the power source in the first state, and switches the switch 40 to the second state (S15). On the other hand, if the communication control unit 73 fails to perform the reception processing of the command (list) (no in S14), the communication control unit 73 returns a reception error to the reader/writer (S16), and the processing ends.
In one embodiment, in S15, the antenna coil 20 is separated from the antenna coil 30, and only the antenna coil 20 is connected to the RF unit 71. In another embodiment, in S15, the antenna coil 30 is connected to the antenna coil 20 in a clockwise manner.
Then, the RF tag 1 waits for a command (read or write) to be transmitted from the reader/writer. When a command (read or write) is transmitted from the reader/writer, the communication control unit 73 performs a reception process of the command (read or write) (S16).
When the communication control unit 73 successfully performs the reception processing of the command (read or write) (yes at S18), the communication control unit 73 returns the reception normal completion to the reader/writer (S19). When the command is read, the read memory data of the RF tag 1 is returned to the reader/writer. If the communication control unit 73 fails to receive the command (read or write) (no in S18), the communication control unit 73 returns a reception error to the reader/writer (S20). The process is ended as described above.
By the above processing, the RF tag 1 can be switched to the second state and perform communication at a position sufficiently close to the reader/writer where the main control section 70 normally operates in the first state. This enables stable communication.
[ embodiment 2 ]
Another embodiment of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiments are given the same reference numerals, and the explanation thereof will not be repeated.
Fig. 4 is a block diagram showing a configuration example of a main part of the RF tag 5 of the present embodiment. An example of the hardware configuration of the RF tag 5 will be described with reference to fig. 4. In the example of fig. 4, the RF tag 5 includes an antenna coil 20, an antenna coil 30, and a main control unit (control unit) 70. The main control unit 70 includes an RF unit 71, an RF unit 72, and a communication control unit 74. The communication control unit 74 includes a determination unit 75. The determination unit 75 includes an addition unit 76, a comparator 77, and a storage unit 78.
The RF section 72 has the same function as the RF section 71. The antenna coil 20 is connected to the RF unit 71, and the RF unit 71 receives an electromotive force generated in the antenna coil 20 and inputs/outputs a radio signal transmitted/received by the antenna coil 20. The antenna coil 30 is connected to the RF unit 72, and the RF unit 72 receives an electromotive force generated in the antenna coil 30.
The determination unit 75 determines whether or not the electromotive force VA of the antenna coil 20 — the electromotive force VB of the antenna coil 30 is equal to or greater than a predetermined value. The adder 76 calculates VA to VB and outputs the difference Δ V to the comparator 77, and the comparator 77 compares the difference Δ V with a predetermined value (threshold) Vth stored in advance in the storage unit 78. Thus, the determination unit 75 can determine whether or not VA-VB is equal to or greater than the predetermined value Vth.
The communication control unit 74 communicates with the reader/writer using at least the electromotive force VA of the antenna coil 20 as a power supply when VA-VB is equal to or greater than the predetermined value Vth, based on the determination result of the determination unit 75. In one embodiment, when VA-VB is equal to or greater than a predetermined value Vth, the communication control unit 74 communicates with the reader/writer using the electromotive force VA of the antenna coil 20 and the electromotive force VB of the antenna coil 30 as power supplies. This enables more stable communication.
Fig. 5 is a flowchart showing an example of processing of the RF tag 5. An example of processing of the RF tag 5 is described based on the flowchart of fig. 5. The process flow described below is merely an example, and each process may be changed as far as possible. In addition, the process flow described below can be appropriately omitted, replaced, and added according to the embodiment.
First, from a state where no electromotive force is supplied to the RF tag 5 and the RF tag 5 is not operated, an electromotive force is supplied to the RF tag 5 by a magnetic field generated by the reader/writer. When the voltage of the generated electromotive force is higher than the activation voltage of the RF tag 5 (yes at S30), the RF tag 5 starts operating. On the other hand, if the voltage of the generated electromotive force is lower than the activation voltage of the RF tag 5 (no in S30), the RF tag 5 is not activated sufficiently and cannot operate (S31), and the process ends.
The RF tag 5 which starts the action waits for a command (list) to be transmitted from the reader/writer. When the command (list) is transmitted from the reader/writer, the communication control unit 74 performs a command (list) reception process (S32).
The adder 76 subtracts the electromotive force VB of the antenna coil 30 from the electromotive force VA of the antenna coil 20 generated in the reception process of S32, and outputs the difference Δ V to the comparator 77 (S33). The comparator 77 compares the difference Δ V with a predetermined value (threshold) Vth stored in the storage unit 78 in advance (S34). If the comparator 77 determines that Δ V ≧ Vth (yes at S35), the RF tag 5 waits for a command (list) to be transmitted from the reader/writer. On the other hand, if the comparator 77 determines that Δ V ≧ Vth is not present (no in S35), the communication control unit 74 returns a reception error to the reader/writer (S37), and the process ends.
When a command (read or write) is transmitted from the reader/writer, the communication control unit 74 performs a command (read or write) reception process (S36).
When the communication control unit 74 has successfully performed the reception process of the command (read or write) (yes at S38), the communication control unit 74 returns the reception normal completion to the reader/writer, and returns the response (response) to the command (read or write) to the reader/writer (S39). If the communication control unit 74 fails to receive the command (read or write) (no in S38), the communication control unit 73 returns a reception error to the reader/writer (S40). The process is ended as described above.
According to the above-described processing, as described in embodiment 1, since the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30 becomes an index of the distance from the reader/writer, when the electromotive force VA of the antenna coil 20 — the electromotive force VB of the antenna coil 30 is equal to or greater than a predetermined value, the RF tag 5 communicates with the reader/writer using at least the electromotive force VA of the antenna coil 20 as a power supply, and thus can perform communication stably.
[ embodiment 3 ]
Another embodiment of the present invention will be described below. For convenience of explanation, members having the same functions as those described in the above embodiments are given the same reference numerals, and the explanation thereof will not be repeated.
The hardware configuration of the RF tag in the present embodiment is different from that of the RF tag 5 in embodiment 2 only in the processing to be executed.
Fig. 6 is a flowchart showing an example of processing of the RF tag in the present embodiment. An example of processing of the RF tag in the present embodiment will be described based on the flowchart of fig. 6. The process flow described below is merely an example, and each process may be changed as far as possible. In addition, the process flow described below can be appropriately omitted, replaced, and added according to the embodiment. Further, a part of the processing may be performed in parallel with other processing or performed in a changed order. In addition, steps for performing the same processing as the steps described in the above embodiment are denoted by the same reference numerals, and the description thereof will not be repeated.
In the present embodiment, when the comparator 77 determines that Δ V ≧ Vth in S35 (yes in S35), the communication control unit 74 determines the communication stabilization flag (flag) to be 1 (a value indicating communication stabilization) (S41). On the other hand, if the comparator 77 determines that Δ V ≧ Vth (no in S35), the communication control unit 74 determines the communication stability flag to be 0 (a value indicating communication instability) (S42). When the communication control unit 74 determines the communication stable flag, the communication control unit 74 performs a command (read or write) reception process (S36). When the communication control unit 74 has successfully performed the reception process of the command (read or write) (yes at S38), the communication control unit 74 returns the reception normal completion to the reader/writer, and returns the response to the command (read or write) to the reader/writer (S43). At this time, the communication control unit 74 adds a communication stability flag to the response and transmits the response.
According to the above-described processing, the RF tag of the present embodiment can notify the reader/writer of information (communication stability flag) indicating the result of determining the communication stability, based on the difference between the electromotive force of the antenna coil 20 and the electromotive force of the antenna coil 30. For example, the reader/writer displays the stable state of communication by a Light Emitting Diode (LED) or the like based on the communication stability flag, and thereby can notify the user side of the stable state of communication. Therefore, when the communication is unstable, the user can be prompted to adjust the position relation between the reader-writer and the RF tag.
[ implementation by software ]
The control blocks (particularly, the main control section 70) of the RF tags 1 and 5 can be realized by a logic circuit (hardware) formed on an integrated circuit (IC chip) or the like, or can be realized by software.
In the latter case, the RF tags 1 and 5 include a computer that executes instructions of a program that is software for realizing the respective functions. The computer includes, for example, one or more processors (processors), and a computer-readable recording medium storing the program. In the computer, the processor reads and executes the program from the recording medium, thereby achieving the object of the present invention. As the processor, for example, a Central Processing Unit (CPU) can be used. As the recording medium, "a non-transitory tangible medium" may be used, and for example, a tape (tape), a disk (disk), a card, a semiconductor Memory, a programmable logic circuit, or the like may be used in addition to a Read Only Memory (ROM) or the like. Further, the system may further include a Random Access Memory (RAM) for expanding the program. Further, the program may be supplied to the computer via an arbitrary transmission medium (a communication network, a broadcast wave, or the like) that can transmit the program. Further, an embodiment of the present invention can be realized as a data signal embedded in a carrier wave in which the program is realized by electronic transmission.
The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims, and embodiments obtained by appropriately combining technical components disclosed in different embodiments are also included in the technical scope of the present invention.
Claims (10)
1. A radio frequency tag, comprising:
a first antenna coil;
a second antenna coil disposed to face the first antenna coil; and
a switch configured to switch between a first state in which the second antenna coil is connected to the first antenna coil in a manner that the second antenna coil is reversely wound with respect to the first antenna coil and a second state in which the second antenna coil is not reversely wound with respect to the first antenna coil.
2. The radio frequency tag of claim 1, comprising:
a control unit for switching the switch,
in the first state, the control unit switches the switch to the second state when the control unit normally operates using electromotive forces generated by the first antenna coil and the second antenna coil as a power source.
3. A radio frequency tag as claimed in claim 1 or 2, wherein
The second state is a state in which the second antenna coil is blocked with respect to the first antenna coil.
4. A radio frequency tag as claimed in claim 1 or 2, wherein
The second state is a state in which the second antenna coil is wound and connected in the forward direction with respect to the first antenna coil.
5. A radio frequency tag, comprising:
a first antenna coil;
a second antenna coil disposed to face the first antenna coil; and
a control unit for inputting an electromotive force VA of the first antenna coil and an electromotive force VB of the second antenna coil,
if VA-VB is greater than or equal to the predetermined value,
the control section communicates with the reader/writer using the electromotive force VA of at least the first antenna coil as a power supply.
6. The radio frequency tag according to claim 5, wherein
If VA-VB is greater than or equal to the predetermined value,
the control section communicates with the reader/writer using the electromotive force VA of the first antenna coil and the electromotive force VB of the second antenna coil as power supplies.
7. A radio frequency tag as claimed in claim 5 or 6, wherein
The first antenna coil is disposed on the reader/writer side as a communication target than the second antenna coil.
8. A radio frequency tag as claimed in claim 5 or 6, wherein
An inner circumference of the second antenna coil is smaller than an inner circumference of the first antenna coil.
9. A radio frequency tag as claimed in claim 5 or 6, wherein
An axis of the first antenna coil coincides with an axis of the second antenna coil.
10. A radio frequency tag as claimed in claim 5 or 6, wherein
The number of turns of the first antenna coil is greater than the number of turns of the second antenna coil.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2019055346A JP7021657B2 (en) | 2019-03-22 | 2019-03-22 | RF tag |
| JP2019-055346 | 2019-03-22 |
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| Publication Number | Publication Date |
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| CN111723895A true CN111723895A (en) | 2020-09-29 |
| CN111723895B CN111723895B (en) | 2024-04-02 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202010089822.7A Active CN111723895B (en) | 2019-03-22 | 2020-02-13 | Radio frequency tag |
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| JP (1) | JP7021657B2 (en) |
| CN (1) | CN111723895B (en) |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070008140A1 (en) * | 2005-06-14 | 2007-01-11 | Mikko Saarisalo | Tag multiplication |
| US20070095925A1 (en) * | 2005-10-29 | 2007-05-03 | Magnex Corporation | RFID chip and antenna with improved range |
| JP2007194924A (en) * | 2006-01-19 | 2007-08-02 | Yokogawa Electric Corp | Antenna, and radio tag device and radio tag communication device using same |
| CN101042727A (en) * | 2006-03-20 | 2007-09-26 | 旺宏电子股份有限公司 | Systems and methods for enhancing communication in a wireless communication system |
| JP2007281818A (en) * | 2006-04-05 | 2007-10-25 | Sony Corp | Non-contact ic card, antenna operation switching method and portable terminal |
| CN101387709A (en) * | 2007-07-20 | 2009-03-18 | 施耐德电器工业公司 | Inductive proximity detector with switched windings |
| JP2010067134A (en) * | 2008-09-12 | 2010-03-25 | Sony Corp | Reader/writer, communication method, and program |
| CN201590479U (en) * | 2009-12-15 | 2010-09-22 | 北京握奇数据系统有限公司 | Non-contact antenna, antenna array and smart card |
| JP2010226574A (en) * | 2009-03-25 | 2010-10-07 | Maxell Seiki Kk | Ic tag for direction discrimination, and method for discriminating direction of work |
| JP2011077976A (en) * | 2009-10-01 | 2011-04-14 | Hitachi Kokusai Electric Inc | Automatic antenna adjusting method |
| JP2012194917A (en) * | 2011-03-17 | 2012-10-11 | Toshiba Corp | Portable electronic device and method of controlling portable electronic device |
| CN104604077A (en) * | 2012-09-05 | 2015-05-06 | 瑞萨电子株式会社 | Non-contact charging device, and non-contact power supply system using same |
| JP2018169966A (en) * | 2017-03-30 | 2018-11-01 | 京セラドキュメントソリューションズ株式会社 | Antenna substrate and image forming apparatus |
| CN109073717A (en) * | 2016-04-04 | 2018-12-21 | 皇家飞利浦有限公司 | RF emission system with the optional driving port for MR imaging apparatus |
| CN109257082A (en) * | 2017-07-14 | 2019-01-22 | 中兴通讯股份有限公司 | A kind of antenna switching handling method, apparatus and system |
| CN208589547U (en) * | 2016-01-13 | 2019-03-08 | 株式会社村田制作所 | Antenna assembly and electronic equipment |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2000295024A (en) * | 1999-04-06 | 2000-10-20 | Sony Corp | Non-contact tag |
| JP2001313515A (en) * | 2000-02-21 | 2001-11-09 | Tamura Electric Works Ltd | Antenna system and contactless ic card reader/writer |
| JP2005218021A (en) * | 2004-02-02 | 2005-08-11 | Fujitsu Frontech Ltd | Small loop antenna for inductive reader/writer |
| JP2011087025A (en) * | 2009-10-14 | 2011-04-28 | Renesas Electronics Corp | Ic card |
-
2019
- 2019-03-22 JP JP2019055346A patent/JP7021657B2/en active Active
-
2020
- 2020-02-13 CN CN202010089822.7A patent/CN111723895B/en active Active
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20070008140A1 (en) * | 2005-06-14 | 2007-01-11 | Mikko Saarisalo | Tag multiplication |
| US20070095925A1 (en) * | 2005-10-29 | 2007-05-03 | Magnex Corporation | RFID chip and antenna with improved range |
| JP2007194924A (en) * | 2006-01-19 | 2007-08-02 | Yokogawa Electric Corp | Antenna, and radio tag device and radio tag communication device using same |
| CN101042727A (en) * | 2006-03-20 | 2007-09-26 | 旺宏电子股份有限公司 | Systems and methods for enhancing communication in a wireless communication system |
| JP2007281818A (en) * | 2006-04-05 | 2007-10-25 | Sony Corp | Non-contact ic card, antenna operation switching method and portable terminal |
| CN101387709A (en) * | 2007-07-20 | 2009-03-18 | 施耐德电器工业公司 | Inductive proximity detector with switched windings |
| JP2010067134A (en) * | 2008-09-12 | 2010-03-25 | Sony Corp | Reader/writer, communication method, and program |
| JP2010226574A (en) * | 2009-03-25 | 2010-10-07 | Maxell Seiki Kk | Ic tag for direction discrimination, and method for discriminating direction of work |
| JP2011077976A (en) * | 2009-10-01 | 2011-04-14 | Hitachi Kokusai Electric Inc | Automatic antenna adjusting method |
| CN201590479U (en) * | 2009-12-15 | 2010-09-22 | 北京握奇数据系统有限公司 | Non-contact antenna, antenna array and smart card |
| JP2012194917A (en) * | 2011-03-17 | 2012-10-11 | Toshiba Corp | Portable electronic device and method of controlling portable electronic device |
| CN104604077A (en) * | 2012-09-05 | 2015-05-06 | 瑞萨电子株式会社 | Non-contact charging device, and non-contact power supply system using same |
| CN208589547U (en) * | 2016-01-13 | 2019-03-08 | 株式会社村田制作所 | Antenna assembly and electronic equipment |
| CN109073717A (en) * | 2016-04-04 | 2018-12-21 | 皇家飞利浦有限公司 | RF emission system with the optional driving port for MR imaging apparatus |
| JP2018169966A (en) * | 2017-03-30 | 2018-11-01 | 京セラドキュメントソリューションズ株式会社 | Antenna substrate and image forming apparatus |
| CN109257082A (en) * | 2017-07-14 | 2019-01-22 | 中兴通讯股份有限公司 | A kind of antenna switching handling method, apparatus and system |
Non-Patent Citations (2)
| Title |
|---|
| ADAM MAUNDER ET AL.: "Comparison of MEMS switches and PIN diodes for switched dual tuned RF coils", MAGNETIC RESONANCE IN MEDICINE, pages 1 - 8 * |
| 戴彩艳等: "13.56MHz RFID读写器天线的设计与仿真", 无线电工程, no. 01, pages 42 - 45 * |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2020155042A (en) | 2020-09-24 |
| JP7021657B2 (en) | 2022-02-17 |
| CN111723895B (en) | 2024-04-02 |
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