JPH10126318A - Noncontact medium and noncontact transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable transmitting and receiving data of a specific noncontact medium to and from a reader/writer by using a receiving device by disconnecting receiving devices for other media, except the specific noncontact medium by a disconnecting device once an overlap detecting device detects an overlap. SOLUTION: An LC parallel resonance circuit 15 constitutes the receiving device for a noncontact medium A, and this device is used to send and receive data. Further, the overlap detection part 22 detects the noncontact media A... overlapping with one another. Once the overlap detection part 22 detects the overlap, a resonance capacitor disconnecting means 23 disconnects a resonance circuit 15 constituting receiving devices for other media other than the specific noncontact media A. For example, when the output waveform of the resonance circuit 15 is less than a specific value, the presence of an overlap is detected. Then a medium having 'order 1' stored in a RAM 26 as the foremost information allowing transmission or reception foremost is set as the medium A and the resonance capacitor 14 for a medium with unstored 'order 2', etc., is disconnected from the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-contact medium and a non-contact transmission system used for a non-contact automatic ticket gate, for example.

[0002]

2. Description of the Related Art A conventional non-contact medium (non-contact card) is configured so that when a plurality of media exist in a communication area for a reader / writer, communication is not performed by a protocol (protocol, communication protocol). Can communicate with all media.

However, the conventional non-contact medium power receiving unit has a resonance circuit. When a plurality of media overlap in a communication area, the mutual inductance of the antenna coil in the medium is added to the resonance circuit. Therefore, since the resonance frequency changes, sufficient power cannot be received, and as a result, there has been a problem that any non-contact card cannot communicate with the reader / writer.

This point will be described in more detail with reference to FIGS. 12 and 13. As shown in FIG.
01 and 102 and the non-contact media 105 and 106 provided with the antenna coils 103 and 104 overlap each other.
Since the antenna coils 103 and 104 of 05 and 106 oppose and approach each other, the mutual inductance M increases. Now, the state of FIG. 12 is modeled as shown in FIG. 13 for convenience of calculation. Thus, this modeled FIG.
When the output E of No. 3 is obtained, it can be expressed by the following [Equation 1].

[0005]

(Equation 1)

When the above [Equation 1] is arranged, it becomes the following [Equation 2].

[0007]

(Equation 2)

Therefore, the resonance point (resonance frequency) when the non-contact media 105 and 106 overlap is expressed by the following [Equation 3]:
It is represented by [Equation 4] and deviates from the original resonance point (resonance frequency) shown by [Equation 5].

[0009]

(Equation 3)

[0010]

(Equation 4)

[0011]

FIG. 5

When the non-contact media 105 and 106 thus overlap, the resonance frequency changes due to the influence of the mutual inductance M, making it impossible to receive sufficient power. There was a problem that communication with the reader / writer became impossible.

[0013]

According to the first aspect of the present invention, when the overlap of the non-contact medium is detected, the receiving means of the other medium except the specific non-contact medium is cut off. It is an object of the present invention to provide a non-contact medium capable of enabling communication with a reader / writer by eliminating a shift in resonance frequency.

According to a second aspect of the present invention, when an overlap of a non-contact medium is detected in a non-contact transmission system including a communication unit for outputting data and a non-contact medium,
An object of the present invention is to provide a non-contact transmission system capable of preventing a shift of a resonance frequency and enabling communication with a reader / writer by separating receiving means of another medium other than a specific non-contact medium. I do.

According to a third aspect of the present invention, in addition to the object of the second aspect, the first information is stored in a specific medium, and the first information is stored when the overlap of the media is detected. By disconnecting the receiving means of the medium in which is not stored, it is possible to enable communication between the specific medium and the reader / writer even when using any combination of media. The purpose is to provide a transmission system.

According to the fourth aspect of the present invention, in addition to the object of the first, second or third aspect of the present invention, it is detected that the output means of the receiving means overlaps when the output waveform is lower than a predetermined value. Accordingly, an object of the present invention is to provide a non-contact medium or a non-contact transmission system capable of performing accurate overlap detection.

The invention described in claim 5 of the present invention has the object of the invention described in claim 1, 2, 3, or 4,
By configuring the receiving means and the resonance circuit, for example, LC
An object of the present invention is to provide a non-contact medium or a non-contact transmission system capable of eliminating a shift in resonance frequency by separating a resonance capacitor of a resonance circuit.

[0018]

According to a first aspect of the present invention, there is provided a non-contact medium for transmitting or receiving data using a receiving means, wherein the overlap detecting means detects an overlap of the non-contact medium. A non-contact medium provided with a disconnecting unit for disconnecting a receiving unit for other medium except for a specific non-contact medium when the overlap detecting unit detects the overlap.

According to a second aspect of the present invention, there is provided a non-contact transmission system including a transmitting unit for outputting data, and a non-contact medium for receiving data from the transmitting unit by receiving means. Overlap detection means for detecting that a plurality of non-contact media are superimposed on the non-contact medium, and when the overlap detection means detects the overlap, disconnect the reception means for other media except for the specific non-contact medium. It is a non-contact transmission system provided with a disconnecting means.

According to a third aspect of the present invention, in addition to the configuration of the second aspect of the present invention, a storage means for storing first information indicating that transmission or reception is performed first on a specific medium. And a disconnecting means for disconnecting the receiving means of the medium for which the earliest information is not stored when the overlap detecting means detects the overlap.

According to a fourth aspect of the present invention, in addition to the configuration of the first, second or third aspect of the present invention, the overlap detecting means overlaps when the output waveform of the receiving means is lower than a predetermined value. A non-contact medium or a non-contact transmission system for detecting that

According to the fifth aspect of the present invention, in addition to the configuration of the first, second, third or fourth aspect of the present invention,
The receiving means is a non-contact medium or a non-contact transmission system constituted by a resonance circuit.

[0023]

According to the first aspect of the present invention, the above-mentioned overlap detecting means detects the overlap of the non-contact medium, and the above-mentioned separating means detects the overlap by the overlap detecting means. Then, the receiving means of the other medium except the specific non-contact medium is disconnected. For this reason, since there is no shift in the resonance frequency, there is an effect that data can be transmitted or received with a reader / writer using a receiving unit in a specific non-contact medium.

According to the second aspect of the present invention,
In a non-contact transmission system including a transmission unit that outputs data and a non-contact medium that receives data, the above-described overlap detection unit detects an overlap of the non-contact medium, and the above-described separation unit overlaps with the overlap detection unit. When is detected, the receiving means of the other medium except the specific non-contact medium is disconnected,
The shift of the resonance frequency is prevented, and as a result, there is an effect that data can be received from the reader / writer using the receiving means in the specific non-contact medium.

According to the invention described in claim 3 of the present invention,
In addition to the effect of the invention described in claim 2, the above-mentioned storage means stores the earliest information indicating that transmission or reception is performed first on a specific medium, and the above-mentioned separation means makes the overlap detection means detect the overlap. When it is detected, the receiving means of the medium in which the earliest information is not stored is disconnected. Therefore, even when a plurality of media are used, there is an effect that communication between the specific medium in which the earliest information is stored and the reader / writer can be performed.

According to the invention described in claim 4 of the present invention,
In addition to the effect of the first, second or third aspect of the present invention, the above-mentioned overlap detecting means detects overlap when the output waveform of the receiving means is lower than a predetermined value.
There is an effect that accurate overlap detection can be performed.

According to the invention described in claim 5 of the present invention,
In addition to the effects of the first, second, third or fourth aspect of the present invention, the above-mentioned receiving means is constituted by a resonance circuit. For example, by disconnecting the resonance capacitor of the LC parallel resonance circuit,
There is an effect that the deviation of the resonance frequency can be eliminated.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. The drawings show a non-contact medium and a non-contact transmission system. In FIG. 1, the non-contact transmission system is a non-contact reader / writer 12 (hereinafter simply abbreviated as a reader / writer) capable of communicating with an upper system (upper device) 11. And a non-contact medium (non-contact card) A.

FIG. 2 is a block diagram showing a control circuit of the above-mentioned non-contact medium A.
4 and an LC parallel circuit 15 is provided.
Are connected to a power receiving unit 18 via lines 16 and 17. An analog switch 19 is provided in series with the above-described resonance capacitor 14, and the analog switch 19 is turned on by a signal from a resonance capacitor separating means 23 described later.
The N and OFF operations are performed to control connection / disconnection of the above-described resonance capacitor 14. However, the resonance capacitor 14 is connected when the power is turned on.

The CPU 20 operates in accordance with the program stored in the ROM 21 so that the overlap detector 22 and the resonance capacitor 2
3. Drive control of the data receiving unit 24 and the data transmitting unit 25, and the RAM 26 stores data corresponding to "rank 1" as an example of the earliest information indicating that the transmission or reception is performed first. The other media are "rank 2" and "rank 3"
The terminal corresponding to “rank 4” is stored.

Here, the above-mentioned LC parallel resonance circuit 15 constitutes a receiving means of the non-contact medium A, and transmits and receives data using the receiving means. Further, the above-described overlap detection unit 22 detects that a plurality of non-contact media A are overlapped. In this embodiment, as shown in FIG. 3B, when the output waveform of the receiving means (see the LC parallel resonance circuit 15) is lower than a predetermined value (when the frequency increases), it is detected that the output waveform overlaps. Further, when the overlap detecting section 22 detects the overlap, the resonance capacitor separating means 23 separates the receiving means of the other medium except the specific non-contact medium A. As a prerequisite, in this embodiment, the medium stored in the RAM 26 is set to the specific medium A with “rank 1” as the earliest information indicating that transmission or reception is performed first, and the overlap detection unit 22 detects the overlap. When this is done, the receiving means (see the resonance capacitor 14) of the medium in which the earliest information is not stored, in other words, the medium of "rank 2", "rank 3", and "rank 4" is disconnected. When the resonance capacitor 14 is disconnected, FIG.
The capacitor on the right side of the model shown in FIG. 3 is disconnected, and the output E becomes as shown in [Equation 6].

[0032]

(Equation 6)

When the media are overlapped, the mutual inductance M is substantially equal to the inductance L, so that a good resonance output can be obtained for the medium of "order 1".

FIG. 3 shows a voltage waveform when the media overlap, a shows a transmission waveform from the reader / writer 12, b shows a change in frequency due to mutual inductance when the media overlaps, As for the reception voltage where there is no transmission waveform (see range d), a waveform that is the product of two sine waves of [Equation 3] and [Equation 4] appears. For this reason, the frequency of the above-mentioned part is measured, and if it is higher than the original frequency, it can be detected that the media overlap. Note that FIG.
Is a timing output waveform when the waveform of b in the figure is envelope-detected and compared with a threshold value.

In order to provide such a function, the above-mentioned overlap detecting section 22 is configured as shown in FIG. That is, the overlap detection unit 22 includes an envelope detector 27, a frequency counter 28, a comparator 29, and a voltage detection circuit 30, and performs envelope detection on the waveform of FIG. Then, a timing signal (see FIG. 3C) is input to a frequency counter 28, an overlap detection output is obtained from a comparator 29, and a voltage detection circuit 30 is connected to the antenna coil 13 so that a voltage detection output Is configured to obtain.

Here, the above-described voltage detection circuit 30 is provided for the following reason. "Rank 1""rank2""rank3"
When using the three media (see the time chart of FIG. 6), when the overlap detection unit 22 detects the overlap of the media,
The resonance capacitors 14 of the other two media (mediums of ranks 2 and 3) except for the specific medium (medium of rank 1) may be separated, but the two media of ranks 2 and 3 are separated. In the case where the medium is used (see the time chart in FIG. 7), the resonance capacitor 14 is separated from the two media of “rank 2” and “rank 3” according to the above method. Is provided, when the power reception voltage is lower than the voltage before disconnection, the resonance capacitor 14 of the medium of “order 2” is connected to enable communication of the medium of the order of priority.

Similarly, by controlling the disconnection / connection of the resonance capacitor 14 at the timing shown in [Table 1] based on the order, the overlap detection, and the detection signal of the voltage drop,
When using any combination of media, the resonance capacitor 14 of the medium having the higher priority is connected, and the other resonance capacitors 14 can be disconnected. In Table 1 below, a circle indicates connection of the resonance capacitor 14 and a cross indicates disconnection of the resonance capacitor 14.

[0038]

[Table 1]

It is needless to say that the contents of [Table 1] may be stored in the storage means as a table. The operation of the non-contact medium and the non-contact transmission system thus configured will be described in detail below with reference to a flowchart shown in FIG. 5 and time charts shown in FIGS.

In the first step S1, the CPU 20 sets the counter to zero (initialization). In the next second step S2, C
The PU 20 performs timing detection by the envelope detector 27 (see the rising portion at the timing of the time point t1 shown in FIGS. 6 and 7). Next, in the third step S3, the CP
U20 stores the power reception voltage V1 or V3 corresponding to the time point t1 in a predetermined area of the RAM 26.

Next, in a fourth step S4, the CPU 20 determines whether or not an overlap of the plurality of non-contact media A has been detected based on the output from the overlap detection unit 22, and terminates the process when a NO determination is made. When the determination is YES, the process proceeds to the next fifth step S5. In the fifth step S5, the CPU 2
0 executes timing detection (see the rising portion at the timing of time t2 shown in FIGS. 6 and 7).

Next, in a sixth step S6, the CPU 20 executes switching of [Table 1]. Here, 1 in [Table 1]
The resonance capacitor 14 in the non-contact medium A of “rank 1” is connected,
Separation of the resonance capacitor 14 in the other non-contact medium A after “order 2” is executed. The capacitor connection / disconnection signals NO1, NO2, NO shown in FIGS.
3 corresponds to “rank 1”, “rank 2”, and “rank 3”.

Next, in a seventh step S7, the CPU 20 executes timing detection (see the rising portion at the timing of the time point t3 shown in FIGS. 6 and 7). Next, in an eighth step S8, the CPU 20 stores the power reception voltage V2 or V4 corresponding to the time point t3 in a predetermined area of the RAM 26.

Next, in a ninth step S9, the CPU 20 determines whether or not a voltage drop is detected. The time chart shown in FIG. 6 shows a case where a total of three non-contact media A of “rank 1”, “rank 2”, and “rank 3” are used. Since no voltage drop is recognized when V1 <V2, the ninth step is performed. In S9, the determination is NO, and the process ends.

The time chart shown in FIG.
This shows a case where a total of two non-contact media A of “order 3” are used, and a voltage drop is recognized when V3> V4, so a YES determination is made in the ninth step S9, and the process proceeds to the next tenth step S10. . In this tenth step S10, the CP
U20 executes the switching of [Table 1]. Here, the resonance capacitor 14 in the non-contact medium A of “order 1” and “order 2” is connected, corresponding to the content of the first time, voltage drop column of [Table 1], and other than “order 3”. The separation of the resonance capacitor 14 in the non-contact medium A is performed.

Next, in an eleventh step S11, the CPU 20
Performs the increment of the counter. That is, after performing the count-up process of switching from the first time to the second time in [Table 1], the process returns to the second step S2, and the same processing as described above is performed by repeating the flowchart below.

As described above, according to the above-mentioned non-contact medium,
The above-mentioned overlap detecting means (see the overlap detecting section 22) detects the overlap of the non-contact medium A, and the above-mentioned separating means (see the resonance capacitor separating means 23) detects a specific non-contact when the overlap detecting means detects the overlap. The receiving means (refer to the resonance circuit 15) of the other medium except the contact medium (refer to the medium of order 1) is disconnected. Because of this, there is no shift in the resonance frequency,
With a specific non-contact medium, there is an effect that data can be transmitted or received with a reader / writer using a receiving unit (see the resonance circuit 15).

According to the above-mentioned non-contact transmission system,
In the non-contact transmission system including the transmission unit of the reader / writer 12 that outputs data and the non-contact medium that receives data, the above-described overlap detection unit (see the overlap detection unit 22) detects the overlap of the non-contact medium A. When the overlap detecting means detects the overlap, the above-mentioned separating means (refer to the resonance capacitor separating means 23) receives the medium other than the specific non-contact medium (refer to the medium of order 1). 1
5), the resonance frequency shift is prevented,
As a result, there is an effect that data can be received from the reader / writer 12 using the receiving means (see the resonance circuit 15) in a specific non-contact medium.

Further, the above-mentioned storage means (see the RAM 26) stores the earliest information (see the first-ranked medium) for transmitting or receiving first in a specific medium, and stores the above-mentioned separating means (resonant capacitor separating). When the overlap detecting means (see the overlap detecting unit 22) detects the overlap, the means for receiving the medium for which the earliest information is not stored is disconnected. For this reason, even when a plurality of media are used, the specific medium storing the earliest information and the reader / writer 1
2 can be communicated with.

In addition, the above-mentioned overlap detecting means (see the overlap detecting section 22) detects the overlap when the output waveform of the receiving means (see the resonance circuit 15) is lower than a predetermined value. There is an effect that detection can be performed. Further, since the above-mentioned receiving means is constituted by the resonance circuit 15, for example, the resonance capacitor 1 of the LC parallel resonance circuit is used.
By separating 4, there is an effect that the deviation of the resonance frequency can be eliminated.

Further, even if the user possesses a plurality of non-contact media A, it can be used while being stacked in a card case or the like. Since it is not necessary to take out the non-contact medium A every time, there is an advantageous effect.

8 and 9 show another embodiment of the non-contact medium and the non-contact transmission system.
Randomly connects / disconnects the capacitor 14,
When non-overlapping is detected, the state is maintained. Even with this configuration, only one non-contact medium can be connected to the resonance capacitor 14.

That is, in the first step S21 of the flowchart shown in FIG. 8, the CPU executes timing detection, and in the next second step S22, the CPU 20 determines whether or not the overlap is detected based on the output from the overlap detector 22. Is determined, and the process ends when the determination is NO, while the process proceeds to the next third step S23 when the determination is YES. In the third step S23, the CPU 20 generates a random number (0 or 1). Here, the random number 0 is for disconnection of the resonance capacitor 14, and the random number 1 is for connection of the resonance capacitor 14.

Next, in a fourth step S24, the CPU 20 executes timing detection, and in a next fifth step S25,
The CPU 20 executes capacitor switching corresponding to a random number (0 or 1). FIG. 9 shows a time chart in this case. The time chart of FIG. 9 shows a medium a, a medium b, and a medium c.
(However, all are non-contact media) when a total of three media are used.

FIGS. 10 and 11 show the above embodiment (FIGS. 1 to 7).
2) is applied to a non-contact medium automatic ticket gate system. Magnetic ticket inserter 31
A passage 34 is formed between a pair of non-contact automatic ticket gates 33 having an antenna coil 32. The reader / writer 12 of the above-mentioned non-contact automatic ticket gate 33 is shown in FIG.
It is configured as shown in FIG.

That is, the CPU 35, in accordance with the program stored in the ROM 36, controls the door controller 37, the non-contact medium controller 38, the magnetic card controller 39, and the display controller 40.
And the RAM 41 stores necessary tables and data.

The non-contact medium control unit 38 includes a power transmission unit 42 for transmitting power to the antenna coil 32,
A data receiving unit 43 for receiving data from the antenna coil 32 and a data transmitting unit 44 for transmitting data to the antenna coil 32 are provided to execute communication with the non-contact medium A via the antenna coil 32. The display controller 40 controls the display of a display 45 for guiding a message or the like to the user.

Even if the above-described non-contact transmission system is applied to the non-contact automatic ticket gate system shown in FIGS. 10 and 11, if the overlap of the non-contact medium A is detected by the processing of the flowchart shown in FIG. Since the resonance capacitor separating means 23 (see FIG. 2) in the medium A separates the receiving means (see the resonance capacitor 14 in the resonance circuit 15) of the other non-contact medium except for the specific non-contact medium A, the resonance frequency can be reduced. The displacement can be prevented, and the specific non-contact medium A has an effect that data can be transmitted / received to / from the reader / writer 12 using the resonance circuit 15 (see FIG. 2).

In the correspondence between the configuration of the present invention and the above-described embodiment, the receiving means of the present invention includes the resonance circuit 1 of the embodiment.
5, the overlap detecting means similarly corresponds to the overlap detecting section 22, the disconnecting means corresponds to the resonance capacitor separating means 23, and the transmitting section for outputting data corresponds to the data transmitting section 44. , The earliest information is ranking information (rank 1
And the storage means corresponds to the RAM 26, but the present invention is not limited to the configuration of the above embodiment. For example, the analog switch 19 in FIG. 2 may have a non-contact structure using a semiconductor switching element instead of the contact switch.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a non-contact medium and a non-contact transmission system according to the present invention.

FIG. 2 is a control circuit block diagram of a non-contact medium.

FIG. 3 is an explanatory diagram of a waveform showing a change in received voltage when media overlap.

FIG. 4 is a block diagram of an overlap detection unit;

FIG. 5 is a flowchart showing capacitor disconnection control when media overlap.

FIG. 6 is a time chart when three media are used.

FIG. 7 is a time chart when two media are used.

FIG. 8 is a flowchart showing another embodiment of the present invention.

FIG. 9 is the same time chart.

FIG. 10 is an explanatory diagram showing a non-contact automatic ticket gate system.

FIG. 11 is a control circuit block diagram of a reader / writer of the contactless automatic ticket gate.

FIG. 12 is a circuit diagram showing an increase in mutual inductance when media overlap.

FIG. 13 is a circuit diagram showing a model of the circuit of FIG. 12;

[Explanation of symbols]

 A: Non-contact medium 15: Resonant circuit 22: Overlap detecting unit 23: Resonant capacitor separating means 26: RAM 44: Data transmitting unit

Claims (5)

[Claims] A non-contact medium for transmitting or receiving data using a receiving means, an overlap detecting means for detecting an overlap of the non-contact medium, and a specific non-contact medium when the overlap detecting means detects the overlap. A non-contact medium provided with a separating unit for separating a receiving unit of another medium other than the contact medium. 2. A non-contact transmission system comprising: a transmitting unit for outputting data; and a non-contact medium for receiving data from the transmitting unit by a receiving unit, wherein the non-contact medium includes a plurality of non-contact media. Non-contact transmission comprising: overlap detection means for detecting that the media are overlapped; and separation means for separating, when the overlap detection means detects the overlap, reception means for other media except for a specific non-contact medium. system. 3. A storage medium for storing the earliest information indicating that transmission or reception is performed first on a specific medium, and a medium on which the earliest information is not stored when the overlap detecting means detects an overlap. 3. A non-contact transmission system according to claim 2, further comprising a disconnecting unit for disconnecting said receiving unit. 4. A non-contact medium or non-contact transmission system according to claim 1, wherein said overlap detecting means detects the overlap when the output waveform of said receiving means is lower than a predetermined value. 5. A non-contact medium or a non-contact transmission system according to claim 1, wherein said receiving means comprises a resonance circuit.