CN111723895B - Radio frequency tag - Google Patents
Radio frequency tag Download PDFInfo
- Publication number
- CN111723895B CN111723895B CN202010089822.7A CN202010089822A CN111723895B CN 111723895 B CN111723895 B CN 111723895B CN 202010089822 A CN202010089822 A CN 202010089822A CN 111723895 B CN111723895 B CN 111723895B
- Authority
- CN
- China
- Prior art keywords
- antenna coil
- electromotive force
- state
- tag
- reader
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004891 communication Methods 0.000 claims abstract description 68
- 238000004804 winding Methods 0.000 claims description 4
- 238000000034 method Methods 0.000 description 21
- 230000008569 process Effects 0.000 description 21
- 238000010586 diagram Methods 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 4
- 230000006870 function Effects 0.000 description 4
- 230000004044 response Effects 0.000 description 4
- 230000005540 biological transmission Effects 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000009471 action Effects 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
Classifications
-
- 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
-
- 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
-
- 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
-
- 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
Abstract
The invention realizes an RF tag capable of stably performing communication. The RF tag (1) comprises: an antenna coil (20); an antenna coil (30) disposed opposite to the antenna coil (20); and a switch (40) for switching between a first state in which the antenna coil (30) is connected so as to be rewound with respect to the antenna coil (20), and a second state in which the antenna coil (30) is not rewound with respect to the antenna coil (20).
Description
Technical Field
The present invention relates to a Radio Frequency (RF) tag.
Background
Radio frequency identification (Radio Frequency Identification, RFID) technology is a technology in which a reader/writer (reader/writer) wirelessly communicates with an RF tag (also referred to as an RFID tag), reads information from the RF tag, or writes information to the RF tag.
RFID technology is utilized in various industrial fields, and readers and RF tags having various structures 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 literature ]
[ patent literature ]
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
[ problem to be solved by the invention ]
However, in the conventional technology described above, the magnetic flux from the reader/writer becomes sparse at a position distant from the reader/writer, and therefore, sufficient electromotive force cannot be supplied to the RF tag. Therefore, if the RF tag is located at a position where power can be supplied only with ease, it is difficult to perform stable communication.
An object of an embodiment of the present invention is to realize an RF tag capable of stably performing communication.
[ means of solving the 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 opposite to 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 so that the second antenna coil is wound back to the first antenna coil, and a second state in which the second antenna coil is not wound back to the first antenna coil.
According to the above configuration, in the first state, the second antenna coil is connected so as to be wound back with respect to the first antenna coil, and therefore the electromotive force generated in the entire antenna coil becomes 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, the distance from the reader/writer to the first antenna coil and the distance from the reader/writer to the second antenna coil are different when in use. 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, and therefore 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 distance of the reader/writer. Therefore, the electromotive force generated in the whole antenna coil in the first state becomes an index of the distance from the reader/writer.
In the second state, the second antenna coil is not rewound with respect to the first antenna coil, and therefore the RF tag can obtain a larger electromotive force than in the first state.
According to the above, the communication is performed by switching to the second state according to the electromotive force obtained in the first state, and thus the communication can be performed stably.
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 by using an electromotive force generated by the first antenna coil and the second antenna coil as a power source in the first state.
According to the above 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 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 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 connected in a forward winding manner 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 a larger electromotive force than in the first state in the second state.
An RF tag according to another aspect of the present invention includes: a first antenna coil; a second antenna coil disposed opposite to the first antenna coil; and a control unit that inputs the electromotive force VA of the first antenna coil and the electromotive force VB of the second antenna coil, and communicates with the reader/writer using at least the electromotive force VA of the first antenna coil as a power source if 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, the distance from the reader/writer to the first antenna coil and the distance from the reader/writer to the second antenna coil are different when in use. 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, and therefore 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 of 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.
According to the 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, the communication can be performed stably by communicating with the reader/writer using at least the electromotive force of the first antenna coil as the power source.
In one embodiment, the control unit 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 sources when VA-VB is equal to or greater than a predetermined value.
According to the above configuration, communication can be performed stably 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 the reader/writer side as a communication target, compared to the second antenna coil.
According to the above configuration, communication can be performed stably by communicating with the reader/writer using the electromotive force of at least the first antenna coil as a power source.
In one embodiment, the inner circumference of the second antenna coil is smaller than the inner circumference of the first antenna coil.
According to the above configuration, even if the interval between the first antenna coil and the second antenna coil is not increased, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be increased. Thus, 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 can be improved without increasing the size of the RF tag.
In one embodiment, the axis of the first antenna coil is coincident with the axis of the second antenna coil.
According to the above 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. Thus, 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 can be improved.
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 the above configuration, even if the interval between the first antenna coil and the second antenna coil is not increased, the difference between the electromotive force of the first antenna coil and the electromotive force of the second antenna coil can be increased. Thus, 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 can be improved without increasing the size of the RF tag.
In addition, the term "RF tag" as used herein generally refers to an information medium that uses electromagnetic waves to read and write information stored in a built-in memory without contact. The information of the RF tag is read and written by a tag communication device (reader/writer). 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 (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 the principle of operation 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: reader-writer
20. 30: antenna coil
40: switch
70: main control part
71. 72: RF part
73. 74: communication control unit
75: determination unit
76: addition unit
77: comparator with a comparator circuit
78: storage unit
Detailed Description
Hereinafter, an embodiment of one side of the present invention (hereinafter, also referred to as "the present embodiment") will be described with reference to the drawings.
[ embodiment 1 ]
Application example of ≡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 principle of operation of the RF tag 1. An example of a scenario in 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.
In the antenna coil 20 and the antenna coil 30, an electromotive force is generated by a magnetic field generated by the reader/writer 2.
The antenna coil 30 is disposed opposite to the antenna coil 20, and therefore, the distance from the reader/writer 2 to the antenna coil 20 and the distance from the reader/writer 2 to the antenna coil 30 are different when 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, in general, the farther from the reader/writer 2, the weaker the magnetic field becomes, and thus a difference in electromotive force occurs between two antenna coils having different distances from the reader/writer 2. For example, the magnetic field HA1 is applied to the antenna coil 20 of the RF tag 1 located at the a position, and the magnetic field HB1 is applied to the antenna coil 30, and since HA1 > HB1, the electromotive force generated in the antenna coil 20 is greater than the electromotive force generated in the 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 near the reader/writer 2 (for example, the a position) and small in the distant place (for example, the B position). 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, the a position), and small in the distance of the reader/writer 2 (for example, the B position). For example, a magnetic field HA2 is applied to the antenna coil 20 of the RF tag 1 located at the B position, and a magnetic field HB2 is applied to the antenna coil 30, and since HA1 to HB1 > HA2 to HB2, the difference between the electromotive force generated in the antenna coil 20 of the RF tag 1 located at the a position and the electromotive force generated in the antenna coil 30 > the difference between the electromotive force generated in the antenna coil 20 of the RF tag 1 located at the B position and the electromotive force generated in the 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 as to be rewound with respect to the antenna coil 20, and a second state in which the antenna coil 30 is not rewound with respect to the antenna coil 20. The second state may be a state in which the antenna coil 30 is blocked from the antenna coil 20, or a state in which the antenna coil 30 is connected to the antenna coil 20 in a forward winding manner.
In the first state, the antenna coil 30 is connected so as to be wound reversely with respect to the antenna coil 20, and therefore, the electromotive force generated in the entire antenna coil becomes 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 whole antenna coil in the first state becomes an index of the distance from the reader/writer 2.
In the second state, the antenna coil 30 is not wound back around the antenna coil 20, and thus the RF tag 1 can obtain a larger electromotive force than in the first state.
The RF tag 1 switches to the second state to perform communication when the position of the reader/writer 2 is sufficiently close to the position based on the electromotive force generated in the whole antenna coil in the first state, and thus can perform communication stably.
2 structural example
[ hardware configuration example of RF tag 1 ]
An example of a 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 back with respect to the antenna coil 20. Specifically, one of the wires of the antenna coil 20 is connected to the RF section 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 section 71. The antenna coil 30 is rewound with respect to the antenna coil 20.
In one embodiment, the switch 40 blocks the antenna coil 30 relative to the antenna coil 20 in the second state. Specifically, one of the wires of the antenna coil 20 is connected to the RF section 71, and the other wire is also connected to the RF section 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 uses the antenna coil 20 to communicate with a reader/writer.
In another embodiment, the switch 40 connects the antenna coil 30 in the second state so as to be wound forward with respect to the antenna coil 20. Specifically, one of the wires of the antenna coil 20 is connected to the RF section 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 section 71. The antenna coil 30 is wound in the same direction as the antenna coil 20.
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 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 a larger electromotive force than 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 closer to the reader/writer to be communicated than the antenna coil 30. Therefore, in the second state, at least the electromotive force generated in the antenna coil 20 is used as a power source. In the case where the antenna coil 30 is disposed closer to the reader/writer than the antenna coil 20, in the second state, at least the electromotive force generated in the antenna coil 30 may be used as a power source.
In addition, in one embodiment, the axis 21 of the antenna coil 20 coincides 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 at 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 accurately represents the distance from the reader/writer. This makes it possible to switch to the second state with good accuracy 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 configured to 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 increased by appropriately selecting the inner circumference, 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 addition, 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. According to 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 interval 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 with high accuracy 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 section 70 controls the respective sections of the RF tag 1. The RF section 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) conversion unit, a Digital/Analog (D/a) conversion unit, a matching circuit, a tuner, a modulation/demodulation circuit, and the like, for example. The communication control unit 73 performs processing of generating a transmission signal and receiving a signal, and controls the switch 40. In the first state, when the main control unit 70 is normally operated by using the electromotive forces generated by the antenna coil 20 and the antenna coil 30 as power sources, 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.
3 action examples
Fig. 3 is a flowchart showing an example of processing of the RF tag 1. An example of processing of the RF tag 1 is described based on the flowchart of fig. 3. The processing flow described below is merely an example, and each processing may be changed as far as possible. The processing flow described below can be appropriately omitted, replaced, or added according to the embodiment.
First, from a state where no electromotive force is supplied to the RF tag 1 but the RF tag 1 is not operated, the electromotive force is supplied to the RF tag 1 by a magnetic field generated by the reader/writer. At this time, the switch 40 may be in the first state or the second state. If the voltage of the generated electromotive force is higher than the start-up voltage of the RF tag 1 (YES in S10), the RF tag 1 starts to operate. On the other hand, if the voltage of the generated electromotive force is lower than the start-up voltage of the RF tag 1 (NO in S10), the RF tag 1 is not sufficiently started up and cannot operate (S11), and the process ends.
When the RF tag 1 starts to operate, 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 reverse winding manner.
Then, the RF tag 1 waits for a command (inventory) to be sent from the reader/writer. When a command (list) is transmitted from the reader/writer, the communication control unit 73 performs a process of receiving the command (list) (S13). When the RF tag 1 receives a 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 considers that the main control unit 70 operates normally by using the electromotive forces generated by the antenna coil 20 and the antenna coil 30 as power sources 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 the reception process of the command (list) (no in S14), the communication control unit 73 returns a reception error to the reader/writer (S16), and the process 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 section 71. In another embodiment, in S15, the antenna coil 30 is connected so as to be wound in a clockwise direction with respect to the antenna coil 20.
Then, the RF tag 1 waits for a command (read or write) to be sent 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).
If the communication control unit 73 successfully performs the reception process of the command (read or write) (yes in S18), the communication control unit 73 returns the normal completion of reception 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 the reception process of the command (read or write) (no in S18), the communication control unit 73 returns a reception error to the reader/writer (S20). The above-described process ends.
By the above processing, the RF tag 1 can be switched to the second state for communication at a position sufficiently close to the reader/writer where the main control unit 70 is normally operated in the first state. This enables stable communication.
[ embodiment 2 ]
Another embodiment of the present invention is described below. For convenience of explanation, members having the same functions as those described in the above-described embodiments are denoted by the same reference numerals, and the description thereof will not be repeated.
Fig. 4 is a block diagram showing a configuration example of a main part of the RF tag 5 according to 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 section 74 includes a determination section 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 section 71, and the RF section 71 inputs an electromotive force generated in the antenna coil 20 and inputs/outputs a wireless signal transmitted/received by the antenna coil 20. The antenna coil 30 is connected to the RF section 72, and the RF section 72 inputs 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-VB and outputs the difference Δv to the comparator 77, and the comparator 77 compares the difference Δv with a predetermined value (threshold value) Vth stored in advance in the memory 78. Thus, the determination unit 75 can determine whether or not VA-VB is equal to or higher than the predetermined value Vth.
Based on the determination result of the determination unit 75, 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 source if VA-VB is equal to or higher than the predetermined value Vth. In one embodiment, if VA-VB is equal to or greater than predetermined value Vth, communication control unit 74 communicates with the reader/writer using electromotive force VA of antenna coil 20 and electromotive force VB of antenna coil 30 as power sources. 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 processing flow described below is merely an example, and each processing may be changed as far as possible. The processing flow described below can be appropriately omitted, replaced, or added according to the embodiment.
First, from a state where no electromotive force is supplied to the RF tag 5 but the RF tag 5 is not operated, the electromotive force is supplied to the RF tag 5 by a magnetic field generated by the reader/writer. If the voltage of the generated electromotive force is higher than the start-up voltage of the RF tag 5 (yes in S30), the RF tag 5 starts to operate. On the other hand, if the voltage of the generated electromotive force is lower than the start-up voltage of the RF tag 5 (no in S30), the RF tag 5 is not sufficiently started up and cannot operate (S31), and the process ends.
The RF tag 5 that starts the operation waits for a command (list) to be transmitted from the reader/writer. When a command (list) is transmitted from the reader/writer, the communication control unit 74 performs a process of receiving the command (list) (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 Δv to the comparator 77 (S33). The comparator 77 compares the difference Δv with a predetermined value (threshold value) Vth stored in advance in the storage unit 78 (S34). If the comparator 77 determines Δv+ Vth (yes in 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 Δv+ 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.
Then, when a command (read or write) is transmitted from the reader/writer, the communication control unit 74 performs a reception process of the command (read or write) (S36).
If the communication control unit 74 successfully performs the reception process of the command (read or write) (yes in S38), the communication control unit 74 returns the normal completion of reception to the reader/writer, and returns a response (response) to the command (read or write) to the reader/writer (S39). If the communication control unit 74 fails the reception process of the command (read or write) (no in S38), the communication control unit 73 returns a reception error to the reader/writer (S40). The above-described process ends.
According to the above 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 and the electromotive force VB of the antenna coil 30 are equal to or greater than a predetermined value, the RF tag 5 uses at least the electromotive force VA of the antenna coil 20 as a power source to communicate with the reader/writer, and thus, stable communication is possible.
[ embodiment 3 ]
Another embodiment of the present invention is described below. For convenience of explanation, members having the same functions as those described in the above-described embodiments are denoted by the same reference numerals, and the description 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 performed.
Fig. 6 is a flowchart showing an example of processing of the RF tag in the present embodiment. A processing example of the RF tag in the present embodiment will be described based on the flowchart of fig. 6. The processing flow described below is merely an example, and each processing may be changed as far as possible. The processing flow described below can be appropriately omitted, replaced, or added according to the embodiment. Further, some of the processes may be performed in parallel with other processes or in a changed order. The steps that perform the same processing as those described in the above embodiment are denoted by the same reference numerals, and the description thereof is not repeated.
In the present embodiment, in S35, if the comparator 77 determines Δv+ Vth (yes in S35), the communication control unit 74 determines the communication stability flag (flag) to be 1 (a value indicating communication stability) (S41). On the other hand, if the comparator 77 determines that Δv+ Vth is not present (no in S35), the communication control unit 74 determines the communication stability flag to be 0 (a value indicating communication instability) (S42). After the communication control unit 74 determines the communication stability flag, the communication control unit 74 performs a reception process of the command (read or write) (S36). If the communication control unit 74 successfully performs the reception process of the command (read or write) (yes in S38), the communication control unit 74 returns the normal completion of reception 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 section 74 transmits a response to the addition of the communication stability flag.
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 steady state of communication by a light emitting diode (Light Emitting Diode, LED) or the like based on the communication steady flag, whereby the steady state of communication can be notified to the user side. Thus, when the communication is unstable, the user can be prompted to adjust the positional relationship between the reader/writer and the RF tag.
[ implementation by means of software ]
The control blocks (particularly, the main control section 70) of the RF tag 1 and the RF tag 5 may be realized by logic circuits (hardware) formed on an integrated circuit (IC chip) or the like, or may be realized by software.
In the latter case, the RF tag 1 and the RF tag 5 include computers that execute commands of programs, which are 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 (Central Processing Unit, CPU) can be used. As the recording medium, "not-transitory tangible medium" may be used, 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, a random access memory (Random Access Memory, RAM) or the like for expanding the program may be further provided. Moreover, the program may be provided to the computer via any transmission medium (communication network or broadcast wave, etc.) that can transmit this program. In addition, an embodiment of the present invention can be realized in the form of a data signal embedded in a carrier wave, which 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 of the claims, and embodiments obtained by appropriately combining technical components disclosed in the different embodiments are also included in the technical scope of the present invention.
Claims (8)
1. A radio frequency tag comprising:
a first antenna coil;
a second antenna coil disposed opposite to the first antenna coil;
a switch that switches between a first state in which the second antenna coil is connected to the first antenna coil so as to be wound back with respect to the first antenna coil, and a second state in which the second antenna coil is not wound back with respect to the first antenna coil, and an electromotive force obtained in the second state is larger than an electromotive force obtained in the first state; and
a control part for switching the switch,
in the first state, the control unit normally operates by using the electromotive forces generated by the first antenna coil and the second antenna coil as power sources, and the control unit switches the switch to the second state, and the normal operation means that the control unit successfully receives a command transmitted from the reader/writer.
2. The radio frequency tag of claim 1, wherein
The second state is a state in which the second antenna coil is blocked with respect to the first antenna coil.
3. The radio frequency tag of claim 1, wherein
The second state is a state in which the second antenna coil is connected in a forward winding manner with respect to the first antenna coil.
4. A radio frequency tag comprising:
a first antenna coil;
a second antenna coil disposed opposite to 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,
the first antenna coil is disposed on the reader/writer side as a communication object with respect to the second antenna coil,
if the VA-VB value is more than or equal to the prescribed value,
the control section communicates with the reader/writer using at least the electromotive force VA of the first antenna coil as a power source.
5. The radio frequency tag of claim 4, wherein
If the VA-VB value is more than or equal to the prescribed 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 sources.
6. The radio frequency tag of claim 4 or 5, wherein
The inner circumference of the second antenna coil is smaller than the inner circumference of the first antenna coil.
7. The radio frequency tag of claim 4 or 5, wherein
The axis of the first antenna coil coincides with the axis of the second antenna coil.
8. The radio frequency tag of claim 4 or 5, 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 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111723895A CN111723895A (en) | 2020-09-29 |
| CN111723895B true CN111723895B (en) | 2024-04-02 |
Family
ID=72559431
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010089822.7A Active CN111723895B (en) | 2019-03-22 | 2020-02-13 | Radio frequency tag |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JP7021657B2 (en) |
| CN (1) | CN111723895B (en) |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 (6)
| 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 |
| WO2006134428A1 (en) * | 2005-06-14 | 2006-12-21 | Nokia Corporation | Tag multiplication |
| US7503491B2 (en) * | 2005-10-29 | 2009-03-17 | Magnex Corporation | RFID chip and antenna with improved range |
| 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 (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
|---|
| 13.56MHz RFID读写器天线的设计与仿真;戴彩艳等;无线电工程(第01期);第42-45页 * |
| Comparison of MEMS switches and PIN diodes for switched dual tuned RF coils;Adam Maunder et al.;Magnetic Resonance in Medicine;第1-8页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| JP7021657B2 (en) | 2022-02-17 |
| JP2020155042A (en) | 2020-09-24 |
| CN111723895A (en) | 2020-09-29 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9269038B2 (en) | Antenna device, card-type communication device, and communication terminal apparatus | |
| EP3214574B1 (en) | Encoded information reading terminal with locate functionality | |
| EP2051191A1 (en) | RFID system capable of detecting RFID tag orientation, an RFID tag thereof, and a puzzle system using the RFID system | |
| US7663486B2 (en) | RFID tag user memory indication | |
| CN101814154A (en) | Information processing device, communication control method and program | |
| EP2701314B1 (en) | Detection of load-modulated NFC signals | |
| JP5935235B2 (en) | COMMUNICATION DEVICE, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD | |
| KR100988813B1 (en) | Multi-mode rfid reader architecture | |
| US10032105B2 (en) | IC card, portable terminal, and portable electronic apparatus | |
| US9773134B2 (en) | Apparatus and method pertaining to switching RFID transceiver read states | |
| JP2015032957A (en) | Proximity wireless transmitting/receiving device | |
| JP4850025B2 (en) | Communication device | |
| CN111723895B (en) | Radio frequency tag | |
| US9912386B2 (en) | Method for operating object capable via contactless communication | |
| JP5034850B2 (en) | Communication system and communication apparatus | |
| US20140145832A1 (en) | Rfid tag including multi-voltage multipliers and operating method thereof | |
| JP2006270813A (en) | Package for radio tag | |
| US20150161421A1 (en) | Apparatus and method for controlling supply of power to radio frequency identification tag | |
| CN111723588A (en) | Read-write machine | |
| CN111490805B (en) | NFC communication | |
| JP7366765B2 (en) | Control program for IC cards, IC card processing systems, and IC card processing devices | |
| JP7092022B2 (en) | Tag communication systems, mobile terminals and control programs | |
| JP2009080687A (en) | Contactless ic card measurement apparatus, contactless ic card measurement method and contactless ic card measurement program | |
| JP2022031327A (en) | Wireless tag reading device and program | |
| CN116562314A (en) | Radio frequency identification communication system, reader-writer and radio frequency identification communication method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |