JP3478151B2 - ID tag transceiver - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ID tag transmitting / receiving apparatus for transmitting / receiving a radio wave signal to / from an ID tag, and more particularly to preventing a radio wave transmitted from a transmitting antenna from reaching a distant place and to a receiving antenna. It relates to the one that can cancel the jumping noise.

[0002]

For example, a remote ID using high frequency radio waves is used as a mobile body identification system.
There is a system. This is for performing communication by radio waves between a controller and an ID tag to read data from an ID tag located at a distant position or write data to the ID tag. The frequency of the radio signal used in this system is, for example, about 125 KHz, and has a stronger magnetic field property.

It is considered that such a remote ID system is applied to various systems such as a delivery system, an inventory management system and a sales system. As an example, there is a totaling system for revolving sushi restaurants. The outline of this system is that the ID tag embedded in the plate on which sushi is placed records the data such as the type of sushi, the time when it was made, and the selling price. Gather in places to communicate with the ID tags on those dishes, and I
The data is obtained from the D-tag and the amount payable by the customer is calculated.

When the remote ID system of a mobile body is applied to the above-mentioned counting system, if the transmitting / receiving device for communicating with the ID tag is of a fixed type, the plate should be carried to the installation place of the transmitting / receiving device. It is inconvenient because it must be done. Therefore, first of all, a hand-held transmitter-receiver device aggregates the number of plates of each type on the table on which the customer is sitting and writes them in the aggregation ID tag, and then brings the aggregation ID tag to the cashier to bring it to the POS terminal. (Terminais for poinnt of
A system has been considered in which a fixed transmission / reception device connected to a sales system) obtains data such as the number of plates for each type of plate from a counting ID tag and calculates the amount of money to be paid by the customer.

In both the fixed type and the handheld type, conventionally considered transmitting / receiving devices, the transmitting and receiving antennas are each formed of one coil and are concentric so that they are superposed in front and back. It is located in. With the transmission / reception antenna having such a configuration, the radio wave (magnetic field) radiated from the transmission antenna reaches a considerable distance, which may cause noise in other electronic devices.

Further, when a radio signal is emitted from the transmitting antenna, an electromotive force is generated in the receiving antenna due to the magnetic flux forming the radio signal, and the receiving antenna receives it as noise. Further, various kinds of radio waves are flying in the air, but there is a problem that the receiving antenna receives such radio waves as environmental noise. For this reason, it is necessary to add a multi-stage band filter or the like to the receiving circuit, which causes a cost increase.

The present invention has been made in view of the above circumstances. An object of the present invention is to shorten the reach of radio waves radiated from a transmitting antenna, and to prevent radio waves transmitted from a transmitting antenna by a receiving antenna. Another object of the present invention is to provide an ID tag transmission / reception device that can prevent the reception of noise and environmental noise as much as possible.

[0008]

Means for Solving the Problems] inventions described in claim 1,
A transmitter for transmitting and receiving radio signals to and from the ID tag
In the ID tag transceiver device having a Tenao standby receiving antenna, the transmitting antenna, a first transmitting antenna unit formed by arranging two coils in which the winding direction opposite to each other symmetrically, one A second transmitting antenna section, in which two coils, which are half the size of the one coil and whose winding directions are reversed, are arranged in line symmetry on both sides of the coil, and the receiving antenna is wound. A first receiving antenna section in which two coils whose directions are opposite to each other are arranged in line symmetry, and a winding direction is reversed on both sides of one coil by half the size of the one coil. A second receiving antenna section having two coils arranged in line symmetry, and the first and second transmitting antenna sections constituting the transmitting antenna,
The first and second receiving antenna sections forming the receiving antenna have the central symmetry lines aligned with each other, and the first and second transmitting antenna sections and the first and second
The center of symmetry with the receiving antenna section of
It is characterized in that the respective antenna parts are arranged side by side so as to overlap with each other so as to be different from each other. This
According to the above configuration, when the radio signal is transmitted from the first transmitting antenna unit, the first transmitting antenna unit is configured to be 2
Since the winding directions of the individual coils are reversed, the magnetic flux amounts of the radio signals radiated from the two coils are approximately equal in the distance, so that the radio signals cancel each other out. Therefore, the radio wave is as much does not reach the distant transmitted from the first transmitting antenna unit.

However, at a place somewhat close to the first transmitting antenna section, except for the adjacent portions of the two coils, the amount of magnetic flux of the radio wave signal transmitted from these coils is different.
As long as the D tag is near the first transmitting antenna unit, the ID tag can normally receive the radio wave signal transmitted from the first transmitting antenna unit.

Further, when transmitting a radio signal from the second transmitting antenna section, the one coil in the center and the two coils on both sides constituting the second transmitting antenna section have opposite winding directions, and Since the area of one coil in the center and the area of two coils on both sides are the same, the radio signals radiated from these coils cancel each other in the distance. However, at a certain position near the second transmitting antenna unit, the magnetic flux amount of the radio signal transmitted from the coils is different except for the adjacent portions of the coils. As long as it's near, its ID tag is first
The radio signal transmitted from the transmitting antenna unit of can be normally received.

On the other hand, since the first receiving antenna section is composed of two coils which are opposite to each other in the winding direction,
Environmental noise penetrates (links) the two coils in equal amounts. Therefore, the electromotive forces generated in the two coils due to the environmental noise cancel each other out, and the first receiving antenna unit does not receive it as noise. However, the ID located near the first receiving antenna part to some extent
With respect to the radio signal transmitted from the tag, since the two coils receive different amounts of magnetic flux, the first receiving antenna unit can normally receive the radio signal transmitted from the ID tag.

The central coil and the two coils on both sides of the second receiving antenna section have opposite winding directions, and the area of one central coil and the two coils on both sides are the same. Are the same, the environmental noise transmits through the central coil and the two coils on both sides in equal amounts. Therefore, the electromotive forces generated in the central coil and the coils on both sides due to the environmental noise cancel each other out, and the second receiving antenna unit does not receive it as noise. However, with respect to the radio signal transmitted from the ID tag located to some extent near the second receiving antenna section, the amount of magnetic flux received by one central coil is different from that of the two coils on both sides. The antenna unit can normally receive the radio signal transmitted from the ID tag.

First and second transmitting antenna sections, and a first
And the direction of the line of symmetry with the second receiving antenna section is 90
Since the radio signal is transmitted from any of the first and second transmitting antenna units, whichever of the first and second receiving antenna units receives the radio signal from the ID tag. Also, the magnetic flux of the radio wave signal transmitted from each coil of the transmitting antenna is transmitted through the coils of opposite windings of the receiving antenna in equal amounts, and the electromotive forces generated by the transmission of the magnetic flux cancel each other out. The radio wave signal transmitted from the transmitting antenna unit is prevented from being received as noise by the receiving antenna unit.

Therefore, by transmitting the radio wave signal from either the first or second transmitting antenna section and receiving the radio wave signal from the ID tag by either the first or second receiving antenna section, the ID Low noise communication can be performed with the tag.

By the way, in the transmitting / receiving antenna of the first aspect of the present invention, for the first transmitting antenna section and the first receiving antenna section, the regions corresponding to the adjacent portions of the two coils, the second transmitting antenna section, and the second transmitting antenna section are provided. In the second receiving antenna unit, the region corresponding to the adjacent portions of the three coils becomes the dead zone, and the ID tag existing in the dead zone cannot be transmitted / received.

However, according to the invention of claim 2,
Since the four combinations of the first and second transmitting antenna units and the first and second receiving antenna units are sequentially switched, the combination of the transmitting antenna and the receiving antenna in which the dead zone does not exist in the place where the ID tag exists. Can be selected and communication with the ID tag can be normally performed.

Further, for example, when communicating with an ID tag,
For the same user, the positional relationship between the ID tag and the transmission / reception device is often the same as the previous communication. In consideration of such a situation, in the invention of claim 3, the combination of the transmitting antenna and the receiving antenna is switched in order from the latest combination that can be transmitted / received to / from the ID tag in the past. Therefore, it becomes possible to communicate immediately, which is convenient for use.

The coils of which the winding directions of the first and second receiving antenna parts are opposite to each other cancel the noise component by interlinking with an equal amount of magnetic flux. In order to interlink with an equal amount of magnetic flux, it is necessary to make the areas of the coils wound in opposite directions equal to each other.
Further, in order to cancel the jumped-in portion of the radio waves transmitted from the first and second transmitting antenna units, the coils must be provided in line symmetry. However, it is very difficult to realize this with a normal winding coil. According to the invention of claim 4, since the coils of the first and second receiving antenna parts are constituted by the circuit pattern on the substrate, they can be accurately formed in the same area and in line symmetry.

According to a fifth aspect of the present invention, the circuit patterns of the two coils of the first receiving antenna section are formed such that the areas surrounded by each turn are the same, and the second receiving antenna section has the same area. The circuit pattern of one coil in the center of the part and two coils on both sides thereof is formed such that the area surrounded by each turn is the same for one coil in the center and two coils on both sides. Therefore, the canceling action of the signal can be more effectively exhibited.

The coils of the first and second receiving antenna parts must be provided in a precise positional relationship in order to complement each other and eliminate the dead zone. In the invention of claim 6,
Since the coils of the first and second receiving antenna parts are formed on the multilayer substrate, they can be arranged at accurate positions and the manufacturing process can be simplified. According to the invention of claim 7, since the Faraday shield pattern is formed on the multi-layer substrate on which the first and second receiving coils are formed, the Faraday shield pattern is formed on the side closer to the ID tag than the portion where the first and second receiving coils are formed. The electric field strength of the environmental noise received by the receiving antenna can be weakened, and the noise can be further reduced.

In the invention of claim 8, since the Faraday shield pattern is connected to the 0 V reference voltage pattern of the plus power source and the minus power source formed on the multilayer substrate, the electric field strength of the environmental noise received by the receiving antenna is increased. Can be weakened more reliably. In the invention of claim 9, since the multi-layered substrate is mounted with the components of the control circuit for controlling transmission / reception with the ID tag, the first and second components are mounted.
A connector for connecting the receiving antenna unit of 1 to the control circuit is not required.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. It should be noted that this embodiment is applied to a totalizing system of a revolving sushi store. Here, the revolving sushi store is a store having the following system. A loop-shaped conveyor is provided in the store, and passenger seats are provided along the conveyor. The sushi is placed on a plate and conveyed by a conveyor to the audience. The customer takes the plate on which the favorite sushi is placed from among the plates carried by the conveyor, and after finishing eating, the plates are placed in order on the table. On the store side, the sushi is placed on a plate of a color or pattern according to the selling price, so that the customer can know the approximate amount to be paid to the store from the plates and the number of the stacked plates. After finishing the meal, the clerk counts the number of plates by color or pattern, and determines the amount to be paid to the store.

The dish 1 on which sushi is placed is shown in FIG. 16, and is made of a plastic such as ABS resin, for example, and an ID tag (not shown) is embedded therein. The ID tag includes the type of plate, the selling price,
The time when sushi was made is recorded.

The sushi plates 1 eaten by the customers are stacked on the table. To calculate the payment amount of a customer who has finished eating, first, operate the handheld transmitter / receiver 2 to communicate with the ID tag of the stacked plates 1 and collect the data obtained from the ID tag to calculate the plate. Predetermined data such as the type of 1 and the number of sheets is created. Then, the totalized data created by the handheld transmitter / receiver 2 is written in the totalization ID tag 3 by transmitting and receiving a radio signal between the handheld transmitter / receiver 2 and the totalization ID tag 3.

As shown in FIG. 14, the totaling ID tag 3 includes an antenna coil 4 for transmitting and receiving radio signals.
The resonance capacitor 5, the control IC 6, and the smoothing unit 7 are mounted on the printed wiring board 8.

The control IC 6 is an MP as a control unit.
U (microprocessor unit) 9 and rectification unit 1
0, the modulation / demodulation unit 11, the memory unit 12, and the like are integrated into a single chip. Also, the smooth portion 7
Has a smoothing capacitor, a Zener diode and the like, which are not shown.

The antenna coil 4 is connected in parallel with the resonance capacitor 5 to form a resonance circuit, and when a transmission / reception device which is an external device transmits a radio wave signal for power of a predetermined high frequency, Upon receiving this, the rectifying unit 10
Send to. The rectifying unit 10 constitutes an operating power supply circuit together with the smoothing unit 7. The rectifying unit 10 rectifies the electric wave signal for electric power transmitted from the resonance circuit, smoothes the electric wave signal by the smoothing unit 7, and supplies DC power of a constant voltage (operating power). ) And supply it to the MPU 9 or the like.

A signal such as data transmitted from the transmitting / receiving device is transmitted by being superimposed on the electric power radio signal, and the signal is demodulated by the modulator / demodulator 11 and given to the MPU 9. The MPU 9 operates according to an operation program stored in the ROM included in the memory unit 12, executes processing according to a signal input from the modulation / demodulation unit 11, and erases received data from an EEPROM or the like included in the memory unit 12. For example, the data is written in a possible nonvolatile memory, the data is read from the memory unit 12, modulated by the modulation / demodulation unit 11, and transmitted as a radio signal from the antenna coil 4.

FIG. 15 shows a fixed transmission / reception device 13 for transmitting / receiving radio wave signals to / from the aggregation ID tag 3. The fixed transmission / reception device 13 is installed at a cashier (accounting) of a sushi store, for example, a POS terminal (terminals for point of
ales system), for example ECR (electronic c
ash register) 14. Then, the fixed transmission / reception device 13 transmits / receives a radio signal to / from the tallying ID tag 3 to obtain predetermined data such as the type of the dish 1 eaten by the customer and the number of the dishes 1, and sends the data to the ECR 14. ECR
14 calculates the amount to be paid by the customer based on the data given from the fixed transmission / reception device 13 and transmits the contents of the data together with the current time information to the management computer.

FIG. 13 is stationary transceiver 1 3 and E
The electrical configuration of CR14 is shown. First, the ECR 14 instructs the control unit 15 to have a register unit 16 having a function similar to that of a conventional cash register, a display unit 17 for displaying payment amount, a printer unit 18 for printing a bill to be given to a customer, and a management unit. Communication unit 19 that communicates with a computer (not shown), communication unit 2 that communicates with fixed transceiver 13
It is configured by connecting 0 and the like.

On the other hand, the stationary transceiver 1 3, to the control unit 21, LCD for transmitting and receiving apparatus 22 for transmitting and receiving radio signals, a display or notification about reception performed between the totalization ID tag 3 (liquid crystal display ) 23, LED (light emitting diode) 24 and buzzer 25, clock unit 26, RAM 28 backed up by battery 27, EC
A communication unit 29 and the like for communicating with R14 are connected.

The control unit 21 of the stationary transceiver device 1 3
As shown in FIG. 12, includes a MPU 30, a ROM 31 storing operation programs, and a RAM 32 for temporarily storing data. On the other hand, the transmitter / receiver 22
Includes a transmission antenna unit 35 including first and second transmission antenna units 33 and 34, and a transmission antenna unit 38 including first and second reception antenna units 36 and 37.

The transmitter / receiver 22 has a transmitter 39 and a receiver 40, and the transmitter 39 uses the first relay 41 as a switching means to connect the first and second transmission antenna units 33 and 34. Selectively connected to either
The receiving section 40 is selectively connected to either the first or second receiving antenna section 36 or 37 by a second relay 42 as a switching means. The above-mentioned first and second relays 41 and 42 are each composed of a switch element using a semiconductor element. The switching state of the first and second relays 41 and 42 is controlled by the MPU 30 via the drive unit 43.

Then, the MPU 30 as the communication control means
When transmitting and receiving with the aggregation ID tag 3, first, the carrier signal is modulated by the transmitting unit 39 and transmitted from the transmitting antenna 35 as a power radio signal, and thereafter, the data to be transmitted is the power radio signal. Then, the signal is modulated by the transmitting unit 39 so as to be superimposed on, and transmitted from the transmitting antenna 35.

The radio wave signal transmitted from the aggregation ID tag 3 is received by the reception antenna 38, demodulated by the reception unit 40, and discriminated as data. And MPU
The storage unit 30 temporarily stores the data demodulated by the reception unit 40 in the RAM 32, and then stores the data together with the calendar date and time measured by the clock unit 26 via the communication unit 29.
It is designed to be sent to the 14 side.

As shown in FIG. 11, the fixed transmitter / receiver 13 accommodates a substrate, a multilayer printed wiring board 45 as a multilayer substrate in this embodiment, in a casing 44, and further, the casing 44 is used as a main body. It is configured to be covered with a case 46. The antenna units 33, 34,
As will be described later, each of 36 and 37 is configured by connecting a plurality of coils in series .
The second transmitting antenna units 33 and 34 are configured as a winding coil formed by winding a wire, and are formed in the first and second grooves 44a and 44b having different depths formed on the upper and lower surfaces of the casing 44. It is arranged. Also, the first
The second receiving antenna portions 36 and 37 are formed on the multilayer printed wiring board 45 by printed wiring means.

The first and second transmitting antenna units 33,
At 34, electric power required for operating the counting ID tag 3 is transmitted by radio waves. Therefore, each transmitting antenna unit 3
A considerably large current flows through the coils of 3,34. If the coils of the first and second transmitting antenna units 33 and 34 are formed by the printed wiring means, the impedance of the coils becomes large and a large current cannot flow.
The coils of the first and second transmitting antenna units 33 and 34 are composed of ordinary winding coils.

Here, each antenna 33, 34, 36, 3
The coil configuration of No. 7 will be specifically described with reference to FIG. That is, (a-1), (a-2), (b-1), (b in FIG.
-2) is for each antenna unit 33, 34, 36, 37,
The relationship among the size, the winding direction (indicated by an arrow), and the disposition position of the plurality of coils forming the antenna part is conceptually shown. First, as shown in FIG. 1 (a-1), the coil configuration of the first transmitting antenna unit 33 includes two coils 33a, 33b of the same size wound in opposite directions with the same number of turns.
Are arranged so as to be line-symmetric with respect to the line A.

The coil configuration of the second transmitting antenna section 34 is, as shown in FIG. 1 (a-2), one coil 34a.
Two coils 34b and 34c are arranged on both sides of the coil. One central coil 34a is formed so as to be line-symmetric with respect to the center line B of itself. The two coils 34b and 34c on both sides have a size and shape obtained by bisecting the coil 34a at the center line C so that the coil 34a is half the area of the central coil 34a, and has the same number of turns as the coil 34a. It is formed so as to be opposite. And
The two coils 34b and 34c are arranged in line symmetry with respect to the center line B of the coil 34a.

The coils 33a and 33b of the first transmitting antenna unit 33 and the coils 34a to 34c of the second transmitting antenna unit 34, which are configured as described above, are respectively provided in the first and second grooves 44a and 44b. Is installed in.
By arranging the coils in the grooves 44a and 44b, the coils 33
The positions of a, 33b, 34a to 34c are accurately determined,
Coil 33a, 3 which constitutes the 1st transmitting antenna part 33
3b and the coil 34 that constitutes the second transmitting antenna unit 34
a to 34c are arranged side by side so as to be vertically overlapped with each other so that the directions of the symmetry lines A and B coincide with each other.

On the other hand, the coil configuration of the first receiving antenna section 36 is, as shown in FIG. 1 (b-1), the same number of turns as the first transmitting antenna section 33, but wound in opposite directions. Two coils 36a and 36b having the same size are arranged so as to be line-symmetric with respect to the line C.

As shown in FIG. 1B-2, the coil structure of the second receiving antenna section 37 is the same as that of the second transmitting antenna section 34. Two coils are provided on both sides of one coil 37a. 37b and 37c are arranged. The single central coil 37a is formed so as to be line-symmetric with respect to its own center line C. Two coils 37 on both sides
b and 34c have a size and shape obtained by dividing the coil 37a in half by the center line D of the coil 37a so as to be half the area of the central coil 37a, and have the same number of turns as the coil 37a but the opposite winding directions. Is formed in. The two coils 37b and 37c are arranged so as to be line-symmetric with respect to the center line D of the coil 37a.

The first and second receiving antenna parts 36
And 37 coils 36a, 36b and 37a-37
Actually, c is formed in each predetermined inner layer of the multilayer printed wiring board 45 in a rectangular substantially spiral pattern as shown in FIGS. 2A and 2B, and is printed on the other inner layers. They are connected in series by wired crossovers (not shown). In this case, the coils 36a and 36b forming the first receiving antenna unit 36 and the coils 37a to 37c forming the second receiving antenna unit 37 are vertically arranged so that their symmetry lines C and D are aligned. Are formed side by side so that they overlap each other.

The multilayer printed wiring board 45 has a first
And the second receiving antenna units 36 and 37 are arranged so as to vertically overlap with the first and second transmitting antenna units 33 and 34, and the lines of symmetry C of the first and second receiving antenna units 36 and 37 are D is first and second
Are arranged so as to be orthogonal to the symmetry lines A and B of the transmitting antenna units 33 and 34. In addition, each antenna unit 33,
The sizes of the outer contours of 34, 36 and 37 are set to be equal.

Of the layers of the multilayer printed wiring board 45, the layers located on the communication direction side (upper side) with the totaling ID tag 3 than the first and second receiving antenna units 36 and 37,
For example, as shown in FIG. 3, a Faraday shield pattern 47 having no closed loop is formed on the upper surface layer.

In each layer of the multilayer printed wiring board 45, the side opposite to the direction of communication with the totaling ID tag 3 (lower side) than the first and second receiving antenna units 36 and 37.
A predetermined circuit pattern is formed on a layer located at, for example, the surface layer on the lower surface, and the circuit pattern is formed through the through holes (neither is shown) of the first and second transmitting antenna units 33 and 34. The coils 33a, 3 constituting the
3b and 34a-34c. And
On the lower surface of the multilayer printed wiring board 45, an electronic component 48 including a communication control circuit for constituting a circuit of the fixed transceiver 13 shown in FIG. 13 is mounted. As a result, wiring work for connecting the electronic component 48 and the coils 33a, 33b and 34a to 34c forming the first and second transmitting antenna units 33 and 34 becomes unnecessary.

The electronic circuit 48 includes a digital circuit and an analog circuit. In particular, analog circuits require positive and negative power supplies. Multilayer printed wiring board 45
A common reference voltage pattern for 0 volt (not shown) is formed on the inner layer of the same as the reference potential of both power supplies. Then, the Faraday shield pattern 47 is
The reference voltage pattern for 0 volt is connected through a through hole.

By the way, the fixed transmission / reception device 13 uses the counting ID.
When communicating with the tag 3, the transmission is performed by one of the first and second transmitting antenna sections 33 and 34, and the reception is performed by one of the first and second receiving antenna sections 36 and 37. Done.

In the transmitting / receiving apparatus 13 of this embodiment, during communication,
It is possible to prevent the radio signal transmitted from the transmitting antenna units 33 and 34 from reaching such a distant place. That is, in the first transmitting antenna unit 33, the two coils 33a and 33b have the same size (area) and the same number of turns, but the winding directions are opposite to each other, so that the radio signals radiated from the respective coils 33a and 33b. Have the same magnetic flux amount but opposite magnetic flux directions. Further, in the distant place, the arrival amount of the magnetic flux radiated from the two coils 33a and 33b becomes substantially the same, so that they cancel each other out. Therefore, the radio signal radiated from the first transmitting antenna unit 33 does not reach so far, and it is possible to suppress environmental noise as much as possible.

Further, in the second transmitting antenna section 34, the central coil 34a is arranged on both sides of the coils 34b, 34.
Since the size (area) is double that of c and the winding direction is opposite, the amount of arrival of the magnetic flux emitted from one coil 34a and the arrival of the magnetic flux emitted from two coils 34b, 34c at a distance. The amount is almost the same and they cancel each other out. Therefore, similarly to the first transmitting antenna section 33, the radio signal radiated from the second transmitting antenna section 34 does not reach that far.

On the other hand, the magnetic fluxes radiated from the coils whose winding directions are opposite to each other are different at a certain distance from the first and second transmitting antenna units 33 and 34, so that the reaching amount is large. One can be received as a radio signal transmitted from the transmitting antenna units 33 and 34.

Further, in the transmitter / receiver 13 of the present embodiment, even if environmental noise jumps into the first and second receiving antenna sections 36 and 37, it is possible not to receive this as noise. That is, in the first receiving antenna unit 36, the two coils 36a and 36b have a size (area).
Is the same, so the environmental noise coming from afar is 2
The same amount of light is transmitted (chained) to the individual coils 36a and 36b. As a result, the electromotive force generated in each of the coils 36a and 36b cancels each other by canceling each other because the coils 36a and 36b have the same number of turns and are reversely wound, and therefore have the same size and opposite directions. . Therefore, the first
In the receiving antenna section 36, the electromotive force due to the environmental noise is practically not generated, and the environmental noise is practically not received.

In the second receiving antenna section 37, since the central coil 37a has a size (area) twice that of the coils 37b and 37c on both sides and the winding direction is opposite, the electromotive force due to environmental noise is The central coil 37a and the coils 37b and 37c on both sides cancel each other out. Therefore, in the second receiving antenna unit 37, the electromotive force due to the environmental noise is practically not generated, and the environmental noise is practically not received.

However, the transmission source is the receiving antenna section 36, 3
In the case where the magnetic flux forming the radio wave signal is smaller than that of No. 7 and is present in a place close to a certain extent, the amounts of the magnetic fluxes constituting the radio wave signals transmitted through the coils having the opposite winding directions in the respective receiving antenna units 36 and 37 are different. Therefore, the difference in electromotive force due to the difference in the flux linkage amount can be received as a radio signal.

In this case, the first and second transmitting antenna units 3
3 and 34 are transmission sources existing in the vicinity of the first and second receiving antenna units 36 and 37, the symmetry lines C and D of the first and second receiving antenna units 36 and 37 are the first and the first. Since it is orthogonal to the symmetry lines A and B of the two transmitting antenna units 33 and 34,
The first and second receiving antenna units 36 and 37 do not receive the transmission radio waves from the first and second transmitting antenna units 33 and 34. The reason will be described below.

First, there are four combinations of the transmitting antenna units 33 and 34 and the receiving antennas 36 and 37. FIG. 6 shows a combination of the first transmitting antenna section 33 and the first receiving antenna section 36. FIG. 3A shows the positional relationship between the two coils 36a and 36b of the first receiving antenna 36 and one coil 33a of the first transmitting antenna 33,
(B) shows two coils 36 of the first receiving antenna 36
a, 36b and the other coil 3 of the first transmitting antenna 33
The positional relationship with 3b is shown. In addition, in FIG.
(+) And (-) indicate the winding direction (the same applies to FIGS. 7 to 9 below).

As shown in FIG. 6 (a), the areas in which the coils 36a and 36b of the first receiving antenna 36 overlap one coil 33a of the first transmitting antenna 33 are the same, so that The transmission amount of the magnetic flux radiated from one coil 33a of the transmitting antenna 33 is substantially the same for each coil 36a and 36b of the first receiving antenna 36. Therefore, the electromotive force generated in each of the coils 36a and 36b by the magnetic flux radiated from the coil 33a has the same magnitude and the opposite directions, so that they cancel each other.

Further, as shown in FIG. 6B, the areas in which the coils 36a and 36b of the first receiving antenna 36 overlap with the other coil 33b of the first transmitting antenna 33 are the same, so The transmission amount of the magnetic flux radiated from the other coil 33b of the one transmitting antenna 33 is substantially the same for each coil 36a and 36b of the first receiving antenna 36. Therefore, the electromotive force generated in each of the coils 36a and 36b by the magnetic flux radiated from the coil 33b also has the same magnitude and the opposite directions, so that they cancel each other out.

In this way, the first magnetic flux emitted from the coils 33a and 33b of the first transmitting antenna 33 causes the first
Since the electromotive forces generated in the coils 36a and 36b of the receiving antenna 36 are canceled out by each other,
The first radio wave signal transmitted from the first transmission antenna 33 is
The receiving antenna 36 does not receive the signal.

FIG. 7 shows a combination of the first transmitting antenna section 33 and the second receiving antenna section 37. FIG. 3A shows three coils 37a of the second receiving antenna 37.
~ 37c and the one coil 33a of the transmitting antenna 33, and FIG.
The positional relationship between the individual coils 37a to 37c and the other coil 33b of the first transmission antenna 33 is shown.

As shown in FIG. 7A, one coil 33a of the first transmitting antenna 33 is connected to the second receiving antenna 3
The area overlapping with the central coil 37a of 7 is the same as the total area where one coil 33a of the first transmitting antenna 33 overlaps with the two coils 37b and 37c on both sides of the second receiving antenna 37. The amount of magnetic flux radiated from the coil 33a passing through one coil 37a at the center and the amount passing through the two coils 37b and 37c on both sides are substantially the same. Therefore, the electromotive force generated in the central coil 37a by the magnetic flux radiated from the coil 33a and the electromotive force generated in the two coils 37b and 37c on both sides have the same magnitude but opposite directions. They will cancel each other out.

As shown in FIG. 7B, the area where the other coil 33b of the first transmitting antenna 33 and the central coil 37a of the second receiving antenna 37 overlap is the area of the first transmitting antenna 33. Since the other coil 33b has the same area as the area where the two coils 37b and 37c on both sides of the second receiving antenna 37 overlap, the magnetic flux radiated from the coil 33b passes through the central one coil 37a. The amount is substantially the same as the amount transmitted through the two coils 37b and 37c on both sides. Therefore, the electromotive force generated in the central coil 37a by the magnetic flux radiated from the coil 33b and the electromotive force generated in the two coils 37b and 37c on both sides have the same magnitude but opposite directions. They will cancel each other out.

As described above, the magnetic flux radiated from the coils 33a and 33b of the first transmitting antenna 33 causes the second
Since the electromotive forces generated in the coils 37a to 37c of the receiving antenna 37 of FIG.
The radio signal transmitted from the first transmitting antenna 33 is
The receiving antenna 37 does not receive the signal.

FIG. 8 shows a combination of the second transmitting antenna section 34 and the first receiving antenna section 36, and FIG. 9 shows a combination of the second transmitting antenna section 34 and the second receiving antenna section 37. Is shown. Also in the case of the combination shown in FIGS. 8 and 9, in the same manner as described above, the coil 36a of the first reception antenna unit 36 is generated by the magnetic flux radiated from the coils 34a to 34c of the second transmission antenna unit 34. And the electromotive forces generated in 36b cancel each other out, and each coil 34a of the second transmitting antenna unit 34
The electromotive force generated in the coil 37a of the second receiving antenna section 37 and the electromotive force generated in the two coils 37b and 37b cancel each other by the magnetic flux radiated from ~ 34c. Therefore, the radio signal transmitted from the second transmitting antenna unit 36 is transmitted to the first and second receiving antenna units 3
6 and 37 are not received as noise.

As described above, in the transmitting antenna 35, the first and second transmitting antenna units 33 and 34 are respectively provided with a plurality of coils 33a, 33b and 34a in order to prevent the transmitted radio waves from reaching a long distance. ~ 34c
Due to the above configuration, there is a dead zone region where radio waves hardly reach even near the transmitting antennas 33 and 34.

This dead zone exists in the boundary area between the coils wound in opposite directions to each other, and occurs in the area of the size of the antenna coil 4 of the ID tag 3. As for the first transmitting antenna unit 33, in the region corresponding to the adjacent portion E of the two coils 33a and 33b (the hatched portion in FIG. 5 (a-1)), the radiation from the coils 33a and 33b is generated. Since the amount of the magnetic flux transmitted through the antenna coil 4 of the ID tag 3 is substantially the same among the generated magnetic flux, the region becomes a dead zone. In the second transmitting antenna section 34, the central coil 34
a and the adjacent portions F1 and F between the coils 34b and 34c on both sides
2 (in the shaded portion in FIG. 5 (a-2)), I in the magnetic flux radiated from the coil 34a
The amount of magnetic flux that passes through the antenna coil 4 of the D tag 3 and the amount of magnetic flux that passes through the antenna coil 4 of the ID tag 3 among the magnetic flux emitted from the coil 34a side half of the coil 34b, and the amount of magnetic flux that is emitted from the coil 34c. ID tag 3 out of magnetic flux
Of the magnetic flux passing through the antenna coil 4 and the coil 34
ID of the magnetic flux radiated from the coil 34c side half of a
Since the amount of magnetic flux passing through the antenna coil 4 of the tag 3 is substantially the same, the region becomes a dead zone.

Further, in the receiving antenna 38, in order to prevent reception of environmental noise and radio waves transmitted from the first and second transmitting antenna sections 33 and 34,
Since the second and second receiving antennas 36 and 37 are composed of a plurality of coils 36a and 36b and 37a to 37c, respectively, the first and second receiving antennas 36 and 37 are formed.
Dead zone occurs.

This dead band is generated by the first receiving antenna section 36.
In FIG. 5B-1, as indicated by hatching, the area corresponds to the adjacent portion G of the two coils 36a and 36b, and in the second receiving antenna section 37,
As shown by hatching in FIG. 5B-2, the adjacent portion H of the central coil 37a and the coils 37b, 37c on both sides
It becomes a region corresponding to 1, H2. The width of the area of the adjacent portions H1 and H2 is slightly larger than the size of the antenna coil 4 of the ID tag 3.

When the ID tag 3 for aggregation is present in this dead zone, an equal amount of magnetic flux is transmitted to each coil 36a and coil 36b in the first receiving antenna section 36, and a central coil is provided in the second receiving antenna section 37. Since an equal amount of magnetic flux is transmitted to 37a and the two coils 37b and 37c on both sides, the magnetic flux allows the coils 36a, 36b and 3
The electromotive forces generated in the coil 7a and the coils 37b and 37c have the same magnitude but opposite directions, so that they cancel each other. Therefore, when the tallying ID tag 3 exists in the dead zone, the first and second receiving antenna units 36 and 37 cannot receive the radio waves from the tallying ID tag 3.

In this way, the first and second transmitting antenna units 3
3, 34 and the first and second receiving antenna units 36, 37
There are dead zones in each. And those first,
There are four combinations of the second transmitting antenna units 33 and 34 and the first and second receiving antenna units 36 and 37 as described above. In any combination, the dead band of the transmitting antenna and the dead band of the receiving antenna are included. ID for any of
If the tag 3 is present, transmission / reception cannot be performed with the aggregation ID tag 3.

For example, the first transmitting antenna section 33 and the first transmitting antenna section 33
When combined with the receiving antenna section 36 of FIG.
The shaded area in 1) is the area where communication is impossible. Hereinafter, the area in which the first transmitting antenna unit 33 and the second receiving antenna unit 37 are incommunicable becomes incommunicable, and
-2), the shaded area, the second transmitting antenna unit 34
The area in which communication is impossible due to the combination of the first receiving antenna section 36 and the first receiving antenna section 36 is the area indicated by hatching in FIG. 10 (b-1), the second transmitting antenna section 34, and the second receiving antenna section 37. The area where communication becomes impossible due to the combination of
The shaded area indicates the area.

In this case, the combination of the transmitting antenna unit and the receiving antenna unit is the combination of the first transmitting antenna unit 33 and the first receiving antenna unit 36, and the combination of the first transmitting antenna unit 33 and the second receiving antenna unit. When switching between the combination of the antenna units 37, the incommunicable area is shown in FIG.
The shaded area is indicated by 0 (a-3). In addition, when switching between the combination of the second transmission antenna unit 34 and the first reception antenna unit 36 and the combination of the second transmission antenna unit 34 and the second reception antenna unit 37, in this case The incommunicable area is a shaded area in FIG. 10B-3.

Furthermore, the first and second transmitting antenna units 33,
When the four combinations of 34 and the first and second receiving antenna units 37 and 38 are switched, eventually, the incommunicable region does not exist. This means that even if the totaling ID tag 3 exists in the dead zone in a certain combination of the transmitting antenna unit and the receiving antenna unit, if the combination of the transmitting antenna unit and the receiving antenna unit is sequentially changed, It means that communication is possible. And the battery 2
The RAM 28 backed up by 7 stores the combinations of the transmitting antenna unit and the receiving antenna unit that have become communicable in a temporal order, and the combinations are first to fourth in order from the latest one. Has been given priority.

The operation of the fixed reader / writer 13 constructed as described above will now be described with reference to the flowchart shown in FIG. Here, in the combination of the transmitting antenna unit and the receiving antenna unit stored in the RAM 28, the first priority is the first transmitting antenna unit 33 and the first receiving antenna unit 37. Set the counting ID tag 3 at a desired position above the fixed reader / writer 13,
When the communication operation is started, the fixed reader / writer 13
The MPU 30 of 1 accesses the RAM 28 and reads the combination of the transmitting antenna unit and the receiving antenna unit defined in the first priority. Then, the MPU 30 switches the first and second relays 41 and 42 via the drive unit 29, and connects the first transmission antenna unit 33 stored as the first priority in the RAM 28 to the transmission unit 39. At the same time, the first receiving antenna unit 36 is connected to the receiving unit 40 (the above is step S1).

After that, the MPU 30 makes the totalization ID tag 3
In order to transmit and receive with the transmitting unit 39, the carrier signal is modulated by the transmitting unit 39 and transmitted as the electric power radio signal from the first transmitting antenna unit 33, and thereafter, the transmitting unit superimposes the data to be transmitted on the electric power radio signal. The signal is modulated by 39 and transmitted from the first transmitting antenna unit 33. On the other hand, on the aggregation ID tag 3 side, the transmitted radio wave signal is received by the antenna coil 4, and the radio wave signal is rectified and smoothed by the rectifying unit 10 and the smoothing unit 7 to be converted into a constant power DC power, and the MPU 9 or the like. It is supplied as a power supply for the operation of

The MPU 9 of the tallying ID tag 3 starts its operation by the supply of the operation power, and the processing corresponding to the content of the transmitted signal, in this case, the plate which the customer has finished eating from the memory section 12 The operation of reading data such as the type and number of 1 and modulating the data by the modulation / demodulation unit 11 and transmitting from the antenna coil 4 is performed. The radio signal transmitted from the counting ID tag 3 is received by the first receiving antenna unit 36 of the fixed reader / writer 13, the received signal is demodulated by the receiving unit 40, and the demodulated data is stored in the RAM 32. (The above is step S2).

After that, the MPU 30 makes the totalization ID tag 3
It is determined whether or not the communication with is normally terminated, and when the communication is normally terminated, the determination is “YES” in step S3, the process proceeds to the next step S14, and the communication is normally terminated on the LCD 23. A message indicating that the communication has been performed is displayed, and the buzzer 25 is sounded to notify that the communication has ended normally. Then MPU30
First, the combination of the transmitting antenna and the receiving antenna (in this case, the first transmitting antenna unit 33 and the first receiving antenna unit 36), which has successfully completed the communication in step S15, is first stored in the RAM 28. Stored as a priority and returned.

By the way, depending on the position of the counting ID tag 3, there is a case where the combination of the transmitting antenna and the receiving antenna of the first priority cannot communicate with the counting ID tag 3. In this case, the MPU 30 determines "N" in step S3.
If it is “O”, the process proceeds to step S5, where RA is again performed.
By accessing M28, the combination of the transmitting antenna and the receiving antenna defined in the second priority is read, and the transmitting antenna and the receiving antenna of the second priority are respectively set in the transmitting unit 3
9 and the receiver 40 (step S4). Then, in this combination, the totalization ID tag 3 is communicated (step S5), and when the communication is normally completed, it is determined to be "YES" in step S6, and the normal communication is notified in step S14. After that, the process proceeds to step S15, where the first combination of transmitting and receiving antennas for which communication has been normally completed is
The combination is stored in the RAM 30 as the priority, and the combination stored as the first priority until then is lowered to the second priority, and the process returns.

When the combination of the transmitting antenna and the receiving antenna of the second priority fails to communicate with the aggregation ID tag 3, the MPU 30 determines "NO" in step S6 and proceeds to step S7. Here, the RAM 28 is accessed to read the combination of the transmitting antenna and the receiving antenna defined in the third priority, and the transmitting antenna and the receiving antenna of the second priority are connected to the transmitting unit 39 and the receiving unit 40, respectively. . Then, with this combination
When the communication with the D-tag 3 is completed (step S8) and the communication is normally completed, it is determined to be "YES" in step S9 and the LCD 23 displays a message indicating that the communication is normally completed and a buzzer is displayed in step S14. After sounding No. 25 to notify that communication is normally completed, the process proceeds to step S15, where the combination of the transmitting and receiving antennas for which communication is normally completed is stored in the RAM 30 as the first priority, and the first communication is performed until then.
The combination stored as the priority is moved down to the second priority, and the combination of the second priority is moved down to the third priority, and a return is made.

When the combination of the transmitting antenna and the receiving antenna of the third priority fails to communicate with the aggregation ID tag 3, the MPU 30 makes a "NO" determination at step S8 and proceeds to step S10. Here, the RAM 28 is accessed to read the combination of the transmitting antenna and the receiving antenna defined in the fourth priority, and the transmitting antenna and the receiving antenna of the fourth priority are connected to the transmitting unit 39 and the receiving unit 40, respectively. . Then, in this combination, the totalization ID tag 3 is communicated (step S11), and when the communication is normally completed, it is determined to be "YES" in step S12, and the normal communication is displayed and notified in step S14. After that, the process proceeds to step S15, where the combination of the transmitting and receiving antennas for which communication has been normally completed is stored in the RAM 30 as the first priority, and the combination stored until then as the first priority is stored as the first priority. The combination of the 2nd priority and the 2nd priority is moved down to the 3rd priority, and the combination of the 3rd priority is lowered to the 4th priority.

When the combination of the transmitting antenna and the receiving antenna defined in the fourth priority fails to communicate with the counting ID tag 3, the MPU 30 determines "NO" in step S12 and determines in step S13. The error status is set in the register and the buzzer 2
5 is sounded to notify the communication error, and the process returns.

After the communication with the totaling ID tag 3 is normally completed and the process returns, the MPU 30 displays the type and number of plates eaten by the customer, the calendar day and time of totaling obtained from the clock unit 26, and the like. The first data is transmitted to ECR14. ECR1
4 calculates the payment amount of the customer from the data and sends the contents of the data to the management computer.

As described above, according to this embodiment, the counting ID
When communicating with the tag 3, it is possible to prevent the radio signal radiated from the transmitting antenna 35 from reaching far, and when the radio signal radiated from the counting ID tag 3 is received by the receiving antenna 38, There is no risk of receiving environmental noise or noise components such as radio signals transmitted from the transmitting antenna 35.

In this case, the first and second receiving antenna units 3
In order that 6 and 37 do not pick up a noise component, in each receiving antenna section 36 and 37, it is necessary for the coils whose winding directions are opposite to transmit an equal amount of magnetic flux, and to transmit an equal amount of magnetic flux. For this reason, it is necessary that the coils whose winding directions are opposite to each other have the same sum of the areas (sizes) surrounding them for each turn. That is, the first receiving antenna unit 3
For 6, one coil 33a and the other coil 33
b, the sum of the surrounding areas for each turn is the same, and in the second receiving antenna 37, the sum of the surrounding areas for each turn of the central coil 37a and the coils 37b, 37c on both sides. It is necessary that the total sum of the surrounding areas is the same for each turn of. Further, in each of the receiving antenna units 36 and 37, it is necessary to arrange coils whose winding directions are opposite to each other in line symmetry.

When the coils forming the first and second receiving coil portions 36 and 37 are formed of ordinary winding coils, it is very difficult to satisfy the above requirements. However, if the coils of the first and second receiving coil portions 36 and 37 are formed by the printed wiring means as in the present embodiment, the above requirements can be satisfied easily.

In order to eliminate the dead zone of reception by switching the receiving antenna section connected to the receiving section 40,
It is necessary to arrange the second receiving antenna units 36 and 37 in an accurate positional relationship. In this embodiment, since the first and second receiving antenna parts 36 and 37 are formed on the multilayer printed wiring board 45, both receiving antenna parts 36 and 37 can be arranged in a precise positional relationship with each other. Further, by forming the first and second receiving antenna units 36 and 37 on the multilayer printed wiring board 45, it is possible to obtain the effect that the receiving antenna 38 can be made thin.

Of course, the first and second transmitting antenna parts 33 and 34 casing 44 are also provided with first and second grooves 44a and 44b.
And 44b, the coils 33a, 33b, and 34a to 34 of the first and second transmitting antenna units 33 and 34, respectively.
Since c is accommodated, the first transmitting antenna unit 3
3 The second transmitting antenna unit 34 can also be arranged in a regular positional relationship, and the multilayer printed wiring board 45 is disposed in a regular position so that the first and second transmitting antenna units 3 can be arranged.
It is possible to maintain a regular positional relationship with both 3, 34 and the first and second receiving antenna units 36, 37.

Regarding the environmental noise, if the noise itself is prevented from reaching the receiving antenna 38, the environmental noise can be more surely not received. The Faraday shield pattern 47 is formed on the multilayer printed wiring board 45 for this purpose. The Faraday shield pattern 47 shields environmental noise, which has a strong character as an electromagnetic wave, from reaching the receiving antenna 38 as much as possible.

Therefore, even if environmental noise passes through the Faraday shield pattern 47, it reaches the receiving antenna 38 in a very weakened state, so that the first and second receiving antenna units 36 are provided. , 37 can reliably prevent environmental noise from being received.

In this case, the Faraday shield pattern 4
7 is connected to the 0 volt reference pattern of the analog circuit. This 0 volt reference pattern includes the first and second
Since one ends of the receiving antenna units 36 and 37 are connected, the voltage generated in the first and second receiving antenna units 36 and 37 becomes a positive and negative current with respect to the 0 volt reference pattern. The electric field component of the space near the Faraday shield pattern 47 is canceled and weakened by the current generated on the Faraday shield pattern 47.

By connecting the Faraday shield pattern 47 to the 0 V reference pattern of the analog circuit, the space potential near the Faraday shield pattern 47 becomes the 0 V reference pattern potential, and the Faraday shield pattern 47 and the first and second Since the second receiving antenna units 36 and 37 are arranged close to each other, the spatial potentials of the first and second receiving antenna units 36 and 37 are the potential of the 0 volt reference pattern, and the 0 volt reference pattern is used. Since the electric field component of noise is weakened with respect to the pattern, the signals generated in the first and second receiving antenna units 36 and 37 can be reduced, and the shield effect is improved.

The radio signal transmitted from the counting ID tag 3 has a shorter distance to the transmitting antenna 35 than the wavelength and has a strong character as a magnetic field. Therefore, it passes through the Faraday shield pattern 47 and becomes normal. Receiving antenna 38
Reach up to.

By the way, in the case of holding the counting ID tag 3 in hand and communicating with the fixed reader / writer 13,
In many cases, the user always brings the counting ID tag 3 to the same position. In consideration of such a situation, the fixed reader / writer 13 is configured to switch the combination of the transmitting antenna and the receiving antenna in order from the latest combination that can be transmitted / received to / from the ID tag in the past. Therefore, it becomes possible to communicate immediately, which is convenient for use.

The present invention is not limited to the embodiments described above and shown in the drawings, and the following expansions and modifications are possible. The present invention is not limited to the fixed reader / writer, but can be widely applied to a handheld reader / writer and other reader / writers that transmit and receive an ID tag and a radio signal. Each coil is not limited to the rectangular shape.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an antenna according to an embodiment of the present invention.

FIG. 2 is a diagram showing an antenna pattern of a multilayer printed wiring board.

FIG. 3 is a diagram showing a Faraday shield pattern.

FIG. 4 is a flowchart showing communication control contents.

FIG. 5 is a diagram showing a dead zone of an antenna.

FIG. 6 is an explanatory diagram of noise cancellation of a receiving antenna, part 1

FIG. 7 is an explanatory diagram of noise cancellation of the receiving antenna, part 2

FIG. 8 is an explanatory diagram 3 of noise cancellation of the receiving antenna.

FIG. 9 is an explanatory diagram of noise cancellation of the receiving antenna, part 4

FIG. 10 is a diagram showing an incommunicable region due to a combination of a transmitting antenna and a receiving antenna.

FIG. 11 is a sectional view of a fixed reader / writer.

FIG. 12 is a block diagram showing an electrical configuration for communication of a fixed reader / writer.

FIG. 13 is a block diagram showing the electrical configuration of a fixed reader / writer and ECR.

FIG. 14 is a block diagram showing an electrical configuration of a counting ID tag.

FIG. 15 is a perspective view of a fixed reader / writer and ECR.

FIG. 16 is a perspective view of a handheld reader / writer.

[Explanation of symbols]

In the figure, 1 is a plate, 3 is a totaling ID tag, 13 is a fixed transmission / reception device, 14 is an ECP, 21 is a control unit, 22 is a transmission / reception device, 30 is an MPU (communication control device), and 33 is the first transmission. Antenna parts, 33a, 33b are coils, 34 is a second transmitting antenna part, 34a to 34c are coils, 35 is a transmitting antenna, 36 is a first receiving antenna part, 36a, 36b.
Is a coil, 37 is a second receiving antenna section, 37a to 37
c is a coil, 38 is a receiving antenna, 41 and 42 are the first and second
The second relay (switching means), 44 is a casing, 45 is a multilayer printed wiring board (substrate, multilayer substrate), 47 is a Faraday shield pattern, and 48 is an electronic component.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-8-222936 (JP, A) JP-A-8-222938 (JP, A) JP-A-9-98014 (JP, A) JP-A-10- 209737 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01Q 7/00 H04B 5/02 G06K 19/07 G06K 19/077

Claims (9)

(57) [Claims] 1. An ID tag transmitting / receiving device comprising a transmitting antenna and a receiving antenna for transmitting and receiving a radio wave signal to and from an ID tag, wherein the transmitting antenna comprises two coils whose winding directions are opposite to each other. A first transmitting antenna section arranged in line symmetry,
And a second transmitting antenna section in which two coils, which are half the size of the one coil and whose winding directions are opposite to each other, are arranged line-symmetrically on both sides of the one coil. And a first receiving antenna section in which two coils whose winding directions are opposite to each other are arranged in line symmetry,
And a second receiving antenna section in which two coils, which are half the size of the one coil and whose winding directions are opposite to each other, are arranged in line symmetry on both sides of the one coil. The first and second transmitting antenna sections that form the first antenna and the second receiving antenna sections that form the receiving antenna have the central symmetry lines in the same direction. in a transmitting antenna section and the first and second receiving antenna section as different directions from each other by 90 degrees of the central line of symmetry and heavy their respective antenna unit vertically
A transmitter / receiver for an ID tag, which is arranged side by side so that 2. The communication between the first and second transmitting antenna units and the ID tag by sequentially switching the combination of the first and second receiving antenna units. The ID tag transmission / reception device according to 1. 3. The combination of the first and second transmitting antenna units and the first and second receiving antenna units is a time-dependent relation in which the combination that can be transmitted and received with the ID tag in the past is time. 3. The ID tag transmission / reception device according to claim 2, wherein the ID tag transmission / reception device is configured to be switched in order from the latest one when the communication is performed with the ID tag. 4. The coil according to any one of claims 1 to 3, wherein each of the coils forming the first and second receiving antenna units is formed of a circuit pattern formed on a substrate. Transceiver for ID tags. 5. The circuit pattern of the two coils of the first receiving antenna section is formed such that the sum of the areas surrounded by each turn is equal, and the circuit pattern of the second coil is the same.
In the circuit pattern of the one coil in the center of the receiving antenna section and the two coils on both sides thereof, the sum of the surrounding areas for each turn is one center coil and two coils on both sides. The ID tag transmitting / receiving device according to claim 4, wherein the transmitting / receiving device and the ID tag are formed to be equal to each other. 6. The ID tag transmission / reception according to claim 4, wherein the circuit pattern forming each of the coils of the first and second reception antenna units is formed on a multilayer substrate. apparatus. 7. The first and second layers are formed on the multilayer substrate.
7. The transmission / reception for an ID tag according to claim 6, wherein a Faraday shield pattern is formed at a position closer to the communication direction with the ID tag than the circuit pattern forming each of the coils of the receiving antenna section. apparatus. 8. The Faraday shield pattern has 0 of a positive power source and a negative power source formed on the multilayer substrate.
The ID tag transmitting / receiving apparatus according to claim 7, wherein the ID tag transmitting / receiving apparatus is connected to a volt reference voltage pattern. 9. The multi-layer substrate includes the first and second layers.
A component of a control circuit, which is located on the side opposite to the direction of communication with the ID tag with respect to the circuit pattern forming each coil of the receiving antenna section, controls transmission and reception with the ID tag. 7. The method according to claim 6, wherein
9. A transmitting / receiving device for an ID tag according to any one of 8 to 8.