JPH11282977A - Tag signal receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a signal-to-noise ratio in reading tag information and to improve the accuracy of read data while eliminating the restrictions of a direction and a space to which a radio tag is turned and highly accurately receiving signals from the radio tag in a wide range in a tag signal contactless receiver at the time of receiving tag signals provided with desired information and transmitted from the radio tag carried by a person or attached to an object at the outside. SOLUTION: This receiver is provided with an excitation coil 1 for generating excitation signals for exciting a tag coil in the radio tag 21, a reception coil part 3A having a plurality of coils which is mutually different in axial directions for receiving the tag signals transmitted for the radio tag with the tag coil excited by the excitation signals, and signal generation parts 2, 10 and 11 for generating signals for reading data included in the plural reception tag signals received in the coils constituting the reception coil part 3A.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is suitable for use in externally receiving a tag signal transmitted from a wireless tag carried by a person or attached to an object containing desired information in a non-contact manner. And a tag signal receiving device.

[0002]

2. Description of the Related Art In recent years, for example, in a distribution system for journalizing articles flowing at random on a conveyor, a wireless tag storing information unique to the article is attached to each of these articles and stored in the wireless tag. A tag information communication system has been developed in which information unique to an article is read by an external receiving and reading device in a non-contact manner, and journal entries are performed based on the read information.

FIG. 11 or FIG. 12 is a diagram showing a tag information communication system. The tag information communication system shown in FIG. 11 or FIG. 12 comprises a receiving / reading device 20 and a wireless tag 21. Are activated upon receiving magnetic energy from the receiving and reading device 20 and transmit tag information, and the receiving and reading device 20 receives a tag signal from the wireless tag 21.

That is, in the receiving / reading device 20, the wireless tag 21 is excited by electromagnetic induction, the desired tag information transmitted from the excited wireless tag 21 is received, and the tag information is demodulated and converted into data. It has become. Here, the receiving and reading device 20 is configured to include an exciting coil 1, an exciting circuit unit 2, a receiving coil 3 and a reading circuit unit 4, and the wireless tag 21 is configured to include a tag coil 6 and a tag IC (Integrated Circuit) 7. The tag IC 7 further includes a memory 5 (see FIG. 12).

The excitation circuit section 2 is constituted by, for example, an AC power supply, and controls the excitation coil 1 by supplying an electric signal for exciting the excitation coil 1. The receiving coil 3 receives the magnetic flux including the tag information generated by the wireless tag 21 as an electric signal, and the tag information received by the receiving coil 3 is amplified and demodulated by the reading circuit unit 4 and converted into data. It is supposed to be.

Further, the memory 5 of the tag IC 7 stores desired information as tag information (information for identifying the article to which the wireless tag 21 is attached, etc.). Tag 2 by the excitation signal of
In order to obtain energy for activating the power supply 1 by electromagnetic induction technology and to transmit the tag information stored in the memory 5.

Therefore, the tag coil 6 has two functions as a coil for receiving energy from the exciting coil 1 and a coil for transmitting data to the receiving coil 3. When the wireless tag 21 is activated by the energy obtained by the tag coil 6, the tag IC 7 stores the tag information stored in the memory 5 into the tag coil 6.
Is controlled to be transmitted via the.

By the way, in the tag information communication system shown in FIG. 11 or FIG.
In order to improve the energy and signal transmission efficiency between the RFID tag 21 and the RFID tag 21, for example, as shown in FIG. It is required that the coils are arranged substantially coaxially and arranged so that the coils face each other.

That is, by arranging the receiving / reading device 20 and the wireless tag 21 as shown in FIG. 13 described above, an excitation signal generated by the excitation coil 1 for the tag coil 6 (a magnetic flux for supplying power to the wireless tag 21). ) 8 can efficiently penetrate the tag coil 6, while the signal magnetic flux (including tag information to be transmitted to the receiving and reading device 20) 9 generated by the tag coil 6 also Can be efficiently penetrated.

[0010]

However, especially when the tag information communication system shown in FIG. 11 or FIG. It is rare that the wireless tag 21 can be arranged so that the coils 6 on the wireless tag 21 side attached to the article moving above are arranged substantially coaxially and face each other.

That is, when the three coils 1, 3, and 6 are arranged substantially coaxially and are not arranged so as to face each other, for example, as shown in FIG. If the wireless tag 21 is tilted without being opposed to the receiving coil 3, the energy received by the wireless tag 21 becomes small, but the magnetic flux which becomes a signal received by the receiving coil 3 also becomes small.

On the other hand, in order to arrange the coils 1, 3, and 6 under the above-described conditions, the method of fixing the wireless tag 21 to the article is restricted or the wireless tag 21 is fixed to the article. When reading the wireless tag 21, the wireless tag 21
However, there is also a problem that it takes time and effort to rearrange the articles so that the articles face the optimum direction with respect to the receiving / reading apparatus 20. Further, in the case where the above-mentioned three coils are arranged coaxially and arranged so as to face each other, there are the above-described problems, and as shown in FIG.
There is also a problem that unnecessary magnetic flux 8 from the exciting coil 1 penetrates and a signal of a weak magnetic flux 9 cannot be demodulated and read.

That is, in the receiving and reading device 20, since the exciting coil 1 and the receiving coil 3 are formed on substantially the same plane, the receiving coil 3 receives the magnetic flux 8 as an exciting signal from the exciting coil 1 in the coil area. Link according to the ratio. Since the excitation signal 8 is usually stronger than the signal 9 from the tag coil 6 to be received, the detection of the excitation signal 8 in the reception coil 3 requires the signal pair of the reception signal detected by the reception coil 3 to be detected. This is a factor that lowers the noise ratio.

On the other hand, while magnetic flux having a frequency of 125 kHz is used for energy transmission by the excitation coil 1, magnetic flux having a frequency of 62.5 kHz is used for signal transmission from the tag coil 6 to the receiving coil 3. And set the frequency to 125 kHz and 6
It is conceivable that a filter circuit (for example, a low-pass filter or a band-pass filter) that removes a 125-kHz signal from a 2.5-kHz signal and extracts a 62.5-kHz signal is read and mounted in the memory circuit unit 4.

However, when a filter circuit is applied to remove the excitation signal 8 contained in the reception signal of the reception coil 3, the frequency transmission characteristic of the filter circuit has a limit. When the frequency is about 125 kHz: 62.5 kHz (= 2: 1) as described above, it is not possible to sufficiently remove the signal in the 125 kHz band.

In other words, when the reading circuit unit 4 amplifies the received signal from the receiving coil 3, the frequency component of the excitation signal 8 which is a disturbance may be removed by a filter circuit. In order to remove the excitation signal 8 which is about twice as high as the frequency of the signal 9 from the filter 9, there is a limit in the characteristics of the filter circuit. In summary, in the tag information communication system shown in FIG. 11 or FIG. 12, in the receiving / reading device 20, there are restrictions on the spatial area for favorably reading the signal from the wireless tag 21, the direction of the wireless tag, and the like.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is intended to eliminate the directional and spatial restrictions to which a wireless tag is directed and to receive a signal from the wireless tag over a wide range and with high accuracy. It is another object of the present invention to provide a tag signal receiving apparatus capable of improving the signal-to-noise ratio when reading tag information and improving the accuracy of read data.

[0018]

According to the present invention, there is provided a tag signal receiving apparatus according to the present invention, wherein an exciting coil for generating an exciting signal for exciting a tag coil in a wireless tag has an axial direction different from that of the exciting coil. A receiving coil unit having a plurality of coils, receiving the tag signal transmitted from the wireless tag by exciting the tag coil by the excitation signal, the plurality of coils, and each coil constituting the receiving coil unit And a signal generation unit that generates a signal for reading data included in the tag signal from the wireless tag from the plurality of reception tag signals received by the wireless tag.

According to a second aspect of the present invention, there is provided the tag signal receiving apparatus according to the first aspect, wherein the plurality of coils constituting the receiving coil section are arbitrarily arranged. Further, in the tag signal receiving apparatus according to the present invention, the plurality of coils are arranged so that the plurality of coils are wound around a sphere with the same center point. It is characterized by that.

According to a fourth aspect of the present invention, there is provided the tag signal receiving apparatus according to the first aspect, wherein the signal generating section cancels a disturbance signal component received by the receiving coil section. A disturbance canceling signal generating section for generating a signal; and a synthesizing section for synthesizing an output from each coil constituting the receiving coil section together with the signal generated by the disturbance canceling signal generating section. It is characterized by having been done.

According to a fifth aspect of the present invention, in the tag signal receiving apparatus of the fourth aspect, the disturbance canceling signal generator detects an excitation signal component generated by the excitation coil. An excitation signal component detector, a phase shifter that inverts the phase of the excitation signal component detected by the excitation signal component detector, and a predetermined level of the signal whose phase is inverted by the phase shifter. And a level adjusting unit for adjusting the speed.

According to a sixth aspect of the present invention, there is provided the tag signal receiving apparatus according to the fifth aspect, wherein the excitation signal component detecting section detects the excitation signal component from a drive signal for driving the excitation coil. Is detected. According to a seventh aspect of the present invention, there is provided the tag signal receiving apparatus according to the fifth aspect, wherein the excitation signal component detecting section detects an excitation signal component generated by the excitation coil by electromagnetic induction. It is characterized by comprising a signal component detecting coil.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a tag information communication system to which a tag signal receiving device according to an embodiment of the present invention is applied. The tag information communication system shown in FIG. And a wireless tag 21 similar to that of FIG.

That is, the wireless tag 21 is activated upon receiving magnetic energy from the receiving / reading device 20A and transmits tag information, while the receiving / reading device 20A transmits the tag signal transmitted from the wireless tag 21. It is designed to receive. Here, the receiving / reading device 20A includes a tag signal receiving unit (tag signal receiving device) 22 and a reading circuit unit 4 similar to that of FIG. 11 described above, and the tag signal receiving unit 22 further includes an excitation circuit. It comprises a unit 2, a receiving coil unit 3A, a combining unit 10, and a cancel signal generating unit 11. In FIG. 1, FIG.
Alternatively, the same reference numerals as those in FIG. 12 indicate the same parts.

That is, the exciting coil 1 is
The excitation circuit section 2 is configured by, for example, an AC power supply or the like, and supplies an electric signal for exciting the excitation coil 1 with an excitation signal of a predetermined frequency. The excitation coil 1 is controlled through the above. Here, the receiving coil unit 3 </ b> A has three coils 31 to 33 whose coil directions are different from each other, and is transmitted from the wireless tag 21 by exciting the tag coil 6 by an exciting signal from the exciting circuit unit 2. The tag signal is received by a plurality of coils 31 to 33.

That is, as shown in FIG. 2A, the receiving coil 3A has a coil 31 having a coil axis parallel to the x-axis on the three-dimensional coordinate axis, and a coil axis parallel to the y-axis on the three-dimensional coordinate axis. The coil 32 is provided with a coil 33 having a coil axis parallel to the z-axis on the three-dimensional coordinate axis, and the coils 31 to 33 are arranged in different directions.

The three coils 31 to 33 are arranged so that their centers coincide with each other. In other words, the three coils 31 to 33 are wound around a sphere with the same center point of each coil 31 to 33. It is arranged to be mounted. Thereby, as shown in FIG. 2B, for example, when the magnetic flux from the tag coil 6 penetrates obliquely to the coils 31 to 33 having three different coil axes, each of the coils 31 to 33 respectively The magnetic flux penetrates according to the direction of the coil axis and the angle formed by the magnetic flux.

That is, since the magnetic flux from the tag coil 6 is received by the three coils 31 to 33 having different coil axis directions, even if the position or the posture of the wireless tag 21 changes, at least two or more coils 31 33, the magnetic flux can be captured, and the capture of the magnetic flux from the tag coil 6 is ensured. In other words, by arranging the plurality of receiving coils 31 to 33 so that the directions of the coil axes are different, even when the position or the direction of the wireless tag changes, any one of the coils 31 to 33 causes the tag from the tag coil 6 to change. The signal can be received.

The cancel signal generating section 11 as a disturbance canceling signal generating section generates a signal for canceling a disturbance signal component received by the receiving coil section 3A. As shown in (1), it comprises an excitation signal English sentence detecting unit 12, a phase adjusting unit 13, and a level adjusting unit 14. That is, the excitation signal component detection unit 12 detects the excitation signal component generated by the excitation coil 1, and as shown in FIG. 4, for example, a drive signal (drive electric signal) for driving the excitation coil 1 ) As a voltage drop value, and an excitation frequency signal serving as an excitation signal component can be detected from a voltage drop component caused by the resistor 12-1.

The phase adjuster 13 shown in FIG. 3 inverts the phase of the excitation signal component detected by the excitation signal component detector 12, and more specifically, as shown in FIG. 13-1 and PLL (Phase Locked Loop)
It is configured to include a circuit section 13-2. Here, the phase shifter 13-1 shifts the phase of the excitation frequency signal detected by the excitation signal component detection unit 180 by 180 degrees, and the PLL circuit unit 13-2 includes the phase shifter 13-1.
The phase comparator 13-3 can output a frequency signal using the excitation frequency signal whose phase has been shifted by 180 degrees as a reference signal, a phase comparator 13-3, a low-pass filter (LPF).
ilter) 13-4 and voltage controlled oscillator (VCO; Voltag)
e Controlled Oscillator) 13-5.

That is, the phase shifter 13-1 and the PL
The L circuit unit 13-2 generates a frequency signal in which the phase of the excitation signal generated by the excitation circuit unit 2 is inverted based on the voltage drop value from the excitation signal component detection unit 12, and generates the generated frequency signal. The signal is output as a signal having a frequency and a phase for removing the excitation signal component received by the receiving coil 3A.

The level adjusting section 14 shown in FIG. 3 adjusts the frequency signal from the phase adjusting section 13 to a predetermined level for removing the excitation signal component received by the receiving coil section 3A. This is configured by, for example, an amplifier whose gain can be adjusted. As a result, in the cancel signal generation unit 11, a signal for canceling the disturbance signal component received by the reception coil unit 3A (a signal having a level equal to the sum of the excitation signals induced in the coils 31 to 33 and having an opposite phase). ) Can be generated by performing phase adjustment and level adjustment on the excitation signal component from the excitation circuit unit 2.

Further, the synthesizer 10 shown in FIG. 1 converts the received signals from the plurality of coils 31 to 33 constituting the receiving coil unit 3A into a signal for canceling a disturbance signal component generated by the cancel signal generating unit 11. And a synthesizing unit, which functions as a synthesizing unit. In other words, the combiner 10 receives the signals from the plurality of coils 31 to 33 and the signal from the cancel signal generation unit 11 without any interference by inputting the signals, and synthesizes (adds) the input signals. In detail, for example, as shown in FIG.
1 to 10-10 and resistors 10-11 to 10-14.

Thus, in the synthesizer 10 shown in FIG. 6, the magnetic flux (tag coil 6
(Including the excitation signal component from the exciting coil 1 together with the tag signal component from the excitation coil 1) are input through the input ports 10a to 10c, respectively, while the signal from the cancel signal generation unit 11 is input through the input port 10d. The input signals are combined and output through the output port 10e.

More specifically, as shown in FIG. 7, a reception tag signal (a tag signal component 10a-1 and an excitation signal component 1a) corresponding to the magnetic flux penetrating the coil 31 is provided to the input port 10a.
0a-2) is input to the input port 10b, and a reception tag signal (tag signal component 10b-1 and excitation signal component 10b-1) corresponding to the magnetic flux penetrating the coil 32 is input to the input port 10b.
10B) is input.

Similarly, a coil 33 is connected to the input port 10c.
Tag signal (tag signal component 1) corresponding to the magnetic flux penetrating through
0c-1 and the excitation signal component 10c-2)
Is input to the input port 10d, and a disturbance canceling signal 10D from the cancel signal generating unit 11 for removing the composite component of the above-described excitation signal components 10a-2 to 10c-2 is input.

In the synthesizer 10, these signals 10A-1A
By combining 0D, the excitation signal component 1 of the signals 10A to 10C received by each of the coils 31 to 33 is output.
0a-2 to 10c-2 of the removed tag signal component 10
The combined signal of a-1 to 10c-1 is output through the output port 10e. Therefore, from the plurality of reception tag signals received by each of the coils 31 to 33 constituting the reception coil unit 3A by the excitation circuit unit 2, the cancel signal generation unit 11, and the combiner 10, the wireless tag 21 is used. Function as a signal generation unit that generates a signal for reading data included in the tag signal.

The synthesized signal from the synthesizer 10 is input to the reading circuit 4 similar to that shown in FIG. 11 as a signal for reading data contained in the tag signal from the wireless tag 21. The reading circuit 4 demodulates and codes the data. With the above configuration, in the tag information communication system to which the tag signal receiving device according to one embodiment of the present invention is applied, as shown in FIG. 1, the exciting coil excited by the exciting circuit unit 2 of the receiving and reading device 20A The excitation signal output from the wireless tag 2
1 is transmitted to the tag coil 6 (see FIG. 11), while the wireless tag 21 is activated by the energy of the excitation signal from the excitation coil 1 and receives and reads the data stored in the memory 5 via the tag coil 6. The data is transmitted to the device 20A.

In the receiving and reading device 20A, the receiving coil unit 3
A signal corresponding to the magnetic flux intersected by each of the coils 31 to 33 constituting A is output to the synthesizer 10 without causing interference, and is received by the receiving coil unit 3A from the excitation signal from the excitation circuit unit 2. A signal for canceling a disturbance signal component is generated. Here, since the coils 31 to 33 have mutually different axial directions, the coils 31 to 33 receive a tag signal from the wireless tag 21 located in a wide range without any directional and spatial restrictions to which the wireless tag 21 faces. But this coil 3
In 1 to 33, in addition to the magnetic flux of the tag signal component from the wireless tag 21 described above, the magnetic flux of the excitation signal component for activating the wireless tag 21 from the excitation coil 1 also intersects. The voltage signal induced by the above includes a signal component that becomes a disturbance when demodulating the tag signal.

On the other hand, the excitation signal component detection section 12 of the cancellation signal generation section 11 detects the excitation signal component from the excitation circuit section 2 and uses this excitation signal component to convert the phase of the disturbance signal and the phase by the phase adjustment section 13. At the same time, by adjusting the level to be equal to the level of the disturbance signal by the level adjuster 14, a signal having a phase opposite to that of the sum of the excitation signals induced in the coils 31 to 33 is generated.

In the combiner 10, for example, as shown in FIG. 7, the output from each of the coils 31 to 33 constituting the receiving coil section 3A is combined with the signal generated by the canceling signal generating section 11 to thereby combine them. For example, as shown in FIG. 7, the signal 10A received by each coil 31-33
-10C, the excitation signal components 10a-2 to 10c-
The combined signal of the tag signal components 10 a-1 to 10 c-1 from which 2 has been removed is output to the reading circuit unit 4.

Thus, in the reading circuit section 4, the tag signal from which the disturbance signal component has been removed with high precision is input as the output of the synthesizer 10, and the tag signal is demodulated and coded while improving the signal-to-noise ratio. I have. As described above, the tag signal receiving apparatus according to the embodiment of the present invention includes the exciting coil 1, the receiving coil unit 3A, the exciting circuit unit 2 as a signal generating unit, the cancel signal generating unit 11, and the combiner 10. As a result, the signal from the wireless tag 21 can be received in a wide range and with high accuracy, so that the method of arranging the articles or fixing the wireless tags 21 to the articles is particularly restricted in a logistics journal that randomly flows on the conveyor. In addition to eliminating the addition, it is also possible to remove the disturbance signal component (mainly the excitation signal component) and demodulate the data by eliminating the directional and spatial restrictions to which the wireless tag 21 is directed, so that the tag information can be read. The advantage is that the signal-to-noise ratio at the time of reading can be improved and the accuracy of the read data can be improved, and, as a result, highly reliable communication of the wireless tag can be realized. A.

According to the present invention, various modifications can be made without departing from the spirit of the present invention, regardless of the above-described embodiment. For example, in the tag signal receiving apparatus according to the above-described embodiment, the resistor 12-1 is provided as the excitation signal component detection unit 12. In addition, for example, as shown in FIG. The excitation signal component detection unit 12 as described above is provided by an excitation signal detection coil
The function as the excitation signal component detection unit 12 may be realized by detecting a tap as an excitation signal component by extracting a tap from the excitation coil 1 as shown in FIG. .

Further, as the receiving coil section 3A in the above-described tag signal receiving apparatus according to the present embodiment, the coils 31 to 33 are wound around a sphere with the same center point of the three coils 31 to 33. Although arranged, the arrangement is not limited to this, and at least two or more coils may be arbitrarily arranged so that the axial directions are different from each other. For example, as shown in FIG. 10, in a logistics system in which articles 41 are provided with a wireless tag 21 in which information unique to the articles is stored and journals are made to flow on a conveyor 40 at random, coils 31 having different axial directions are provided. To 33 may be arranged in the vicinity of the exciting coil 1 with the coil centers being different from each other instead of being the same.
Even in this case, there is an advantage similar to that of the above-described embodiment.

In the above-described tag signal receiving apparatus according to the present embodiment, the excitation coil 1 is constituted by a single coil. However, for example, a plurality of excitation coils 1 may be arranged. This makes it possible to more reliably supply power to the tag coil 6, while improving the signal-to-noise ratio at the time of reading tag information and improving the accuracy of read data as in the above-described case.

Further, the tag signal receiving apparatus according to the above-described embodiment is applied to a tag signal communication system using a read-only wireless tag 21 for reading tag information. However, the present invention is not limited to this. It goes without saying that the tag signal receiving apparatus of the present invention can be easily applied to communication using a wireless tag of a type capable of receiving energy supply from a coil and writing data for recording data in an IC memory. Nor.

[0047]

As described above in detail, according to the tag information receiving apparatus of the present invention, the exciting coil for generating the exciting signal for exciting the tag coil in the wireless tag and the axial direction are mutually opposite. A plurality of coils different from each other, a reception coil unit that receives the tag signal transmitted from the wireless tag by exciting the tag coil with the excitation signal, and the reception coil unit, A signal generating unit that generates a signal for reading data included in the tag signal from the wireless tag from a plurality of received tag signals received by the coil; Eliminate spatial and spatial constraints,
Since the signal from the wireless tag can be received over a wide range and with high accuracy, it is possible to demodulate the data by removing the disturbance signal component (mainly the excitation signal component) and improve the signal-to-noise ratio when reading the tag information. There is an advantage that the accuracy of the read data can be improved, and high reliability communication of the wireless tag can be realized.

According to the second aspect of the present invention, since the plurality of coils constituting the receiving coil section can be arbitrarily arranged, the direction in which the wireless tag is directed can be improved.
Eliminate spatial restrictions, receive signals from wireless tags over a wide area and with high precision, remove disturbance signal components (mainly excitation signal components), demodulate data, and read tag information There is an advantage that the accuracy of read data can be improved by improving the signal-to-noise ratio at the time of wireless communication, and high reliability communication of the wireless tag can be realized.

According to the third aspect of the present invention,
The plurality of coils may be arranged such that the plurality of coils have the same center point and are wound around a sphere, thereby eliminating the directional and spatial restrictions to which the wireless tag is directed, and enabling wireless communication. Since the signal from the tag can be received over a wide range and with high precision, the disturbance signal component (mainly the excitation signal component) can be removed and the data can be demodulated, and the signal-to-noise ratio when reading the tag information can be improved and read. There is an advantage that the accuracy of data can be improved, and thus highly reliable communication of the wireless tag can be realized.

Further, according to the present invention described in claim 4,
The signal generator, a disturbance canceling signal generator for generating a signal for canceling a disturbance signal component received by the receiving coil unit, and an output from each coil constituting the receiving coil unit. By constructing a synthesizing unit for synthesizing together with the signal generated by the disturbance canceling signal generating unit, a disturbance signal component received by the receiving coil unit is canceled, and a tag signal from the wireless tag is generated. Since the signal for reading the included data is generated, the disturbance signal component (mainly the excitation signal component) can be removed to demodulate the data, thereby improving the signal-to-noise ratio when reading the tag information. There is an advantage that the accuracy of the read data can be improved, and high reliability communication of the wireless tag can be realized.

According to the fifth aspect of the present invention, the disturbance canceling signal generator includes an excitation signal component detector that detects an excitation signal component generated by the excitation coil.
A phase shift unit that inverts the phase of the excitation signal component detected by the excitation signal component detection unit; and a level adjustment unit that adjusts the level of the signal whose phase is inverted by the phase shift unit to a predetermined level. With the configuration, the excitation signal component adjusted to a predetermined level and inverted in phase is
The signal is used as a signal for canceling a disturbance signal component received by the reception coil unit, whereby the disturbance signal component (mainly the excitation signal component) can be removed to demodulate the data, and the tag information can be read. There is an advantage that the accuracy of read data can be improved by improving the signal-to-noise ratio at the time of wireless communication, and high reliability communication of the wireless tag can be realized.

Further, according to the present invention described in claim 6,
The excitation signal component detection unit can be configured to detect the excitation signal component from a drive signal for driving the excitation coil, so that a disturbance signal component (mainly an excitation signal component) is removed to demodulate data. So you can
There is an advantage that the signal-to-noise ratio at the time of reading the tag information is improved to improve the accuracy of the read data, and that high-reliability communication of the wireless tag can be realized.

According to the seventh aspect of the present invention, since the excitation signal component generated by the excitation coil can be constituted by an excitation signal component detection coil for detecting by electromagnetic induction, a disturbance signal component can be provided. Since data can be demodulated by removing (mainly the excitation signal component), the signal-to-noise ratio at the time of reading tag information is improved to improve the accuracy of read data, and as a result, highly reliable communication of wireless tags is realized. There are advantages that can be.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a tag information communication system to which a tag signal receiving device according to one embodiment of the present invention is applied.

FIGS. 2A and 2B are schematic diagrams illustrating a magnetic flux intersecting a receiving coil unit in the present embodiment.

FIG. 3 is a block diagram illustrating a cancel signal generator according to the embodiment.

FIG. 4 is a diagram illustrating a main part of a cancel signal generation unit according to the embodiment.

FIG. 5 is a block diagram illustrating a main part of a cancel signal generation unit according to the embodiment.

FIG. 6 is a circuit configuration diagram illustrating a combiner according to the present embodiment.

FIG. 7 is a diagram for explaining an operation example of the synthesizer in the embodiment.

FIG. 8 is a diagram illustrating a main part of a cancel signal generation unit according to another embodiment of the present invention.

FIG. 9 is a diagram illustrating a main part of a cancel signal generation unit according to another embodiment of the present invention.

FIG. 10 is a diagram showing an example of the arrangement of a plurality of coils constituting a receiving coil unit according to another embodiment of the present invention.

FIG. 11 is a diagram showing a conventional tag information communication system.

FIG. 12 is a diagram schematically illustrating a conventional tag information communication system.

FIG. 13 is a diagram showing an example of coil arrangement in a conventional tag information communication system.

FIG. 14 is a diagram showing an example of coil arrangement in a conventional tag information communication system.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 excitation coil 2 excitation circuit section (signal generation section) 3 reception coil 3A reception coil section 4 reading circuit section 5 memory 6 tag coil 7 tag IC 8 excitation magnetic flux 9 signal magnetic flux 10 synthesizer (synthesis section, signal generation section) 10-1 10-10 Coil 10-9-10-12 Resistance 10a-10d Input port 10e Output port 10a-1-10c-1 Tag signal component 10a-2-10c-2 Excitation signal component 10A-10D signal 11 Cancel signal generator (Disturbance cancellation signal generation unit, signal generation unit) 12 Excitation signal component detection unit 12-1 Resistance 12-2 Coil 13 Phase adjustment unit 13-1 Phase shifter 13-2 PLL circuit unit 13-3 Phase comparator 13- 4 Low Pass Filter 13-5 Voltage Controlled Oscillator 14 Level Adjuster 20, 20A Receiving / Reading Device 21 Wireless Tag 31-33 Le 40 conveyor 41 luggage

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H04B 1/59 H04B 1/59 5/00 5/00 Z // B65G 47/49 B65G 47/49 (72) Inventor Takayuki Tomita Kobe, Hyogo-ku, 1-1-1 Wadazakicho Sanishi Heavy Industries, Ltd. Kobe Shipyard

Claims (7)

[Claims] 1. A wireless tag comprising: an excitation coil for generating an excitation signal for exciting a tag coil of a wireless tag; and a plurality of coils having mutually different axial directions, wherein the tag coil is excited by the excitation signal to achieve the wireless communication. A receiving coil unit that receives a tag signal transmitted from a tag by the plurality of coils; and a plurality of receiving tag signals received by each of the coils constituting the receiving coil unit. A tag signal receiving device, comprising: a signal generation unit that generates a signal for reading contained data. 2. The tag signal receiving apparatus according to claim 1, wherein said plurality of coils constituting said receiving coil section are arbitrarily arranged. 3. The tag signal receiving apparatus according to claim 2, wherein the plurality of coils are arranged so that the plurality of coils have the same center point and are wound around a sphere. 4. A disturbance canceling signal generating section for generating a signal for canceling a disturbance signal component received by the receiving coil section, and a coil constituting the receiving coil section. 2. The tag signal receiving apparatus according to claim 1, further comprising a synthesizing unit for synthesizing the output of the tag with the signal generated by the disturbance canceling signal generating unit. 5. An exciting signal component detecting section for detecting an exciting signal component generated by the exciting coil, wherein the disturbance canceling signal generating section detects the exciting signal component detected by the exciting signal component detecting section. A phase shifter for inverting the phase with respect to
5. The tag signal receiving device according to claim 4, further comprising a level adjusting unit that adjusts the level of the signal whose phase is inverted by the phase shift unit to a predetermined level. 6. The tag signal receiving device according to claim 5, wherein said excitation signal component detection section is configured to detect said excitation signal component from a drive signal for driving said excitation coil. apparatus. 7. The excitation signal component detection unit according to claim 5, wherein the excitation signal component detection unit includes an excitation signal component detection coil that detects an excitation signal component generated by the excitation coil by electromagnetic induction. Tag signal receiving device.