JP2001084464A - Antitheft device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To define an area where an alarm is outputted by making an antitheft output the alarm at the time of continuously receiving prescribed signals respectively outputted by two kinds of transmission circuits. SOLUTION: The antitheft tab outputs the alarm when a receiving circuit continuously receives the prescribed signal for a time T1. In such a case, the transmission circuits 13 and 14 respectively output the prescribed signals for times T2 and T3 meeting conditions such as T1>T2, T1>T3, T1<=T2+T3. That is, the respective transmission circuits 13 and 14 of two kinds of gates TXa and TXb for antitheft alternately output the prescribed signals from loop coils 15 and 16 every prescribed second according to phase control from a synchronous circuit 12 to form three areas. When the tag goes into a required area, the tag continuously receives the prescribed signals until a prescribed time passes because the tag alternately receives the prescribed signals from the coils 15 and 16 of the gates TXa and TXb. As a result, the tag rings a buzzer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-theft tag which is attached to an anti-theft object and outputs an alarm when a receiving circuit receives a predetermined signal such as radio waves or ultrasonic waves for a predetermined period of time. , An anti-theft device having an anti-theft gate for outputting the predetermined signal, an anti-theft tag attached to the anti-theft object and outputting another predetermined signal in response to the predetermined signal, and a theft for outputting the predetermined signal The present invention relates to an anti-theft device including an anti-theft gate and an alarm circuit that outputs an alarm when another predetermined signal output by the anti-theft tag is continuously received for a predetermined time.

[0002]

2. Description of the Related Art An anti-theft device is an anti-theft device in which an anti-theft tag is attached to a product to be anti-theft, and the product is provided near an exit of a store without a person taking measures such as removal. The anti-theft gate or the tag itself outputs an alarm when an attempt is made to take it out of the security gate. The anti-theft tag includes a self-sounding anti-theft tag that detects an attached state and a detached state of a product, and outputs an alarm when the detached state is detected and a predetermined signal is received from the anti-theft gate. Has a resonance circuit composed of L and C, is attached to a product, and the resonance circuit resonates with radio waves of a predetermined frequency from the anti-theft gate,
There is a resonance type paper tag or the like that outputs an alarm when the anti-theft gate receives a radio wave transmitted by a resonance circuit due to its resonance.

[0003]

Conventionally, the anti-theft gate is configured to generate a signal such as a continuous electromagnetic wave. However, by this, an alternating magnetic field is formed around the anti-theft gate in all directions. For example, when an anti-theft gate is installed at the entrance, the area where the anti-theft tag issues an alarm is formed in a direction other than the required frontage direction. For this reason, there is a problem that the anti-theft tag generates an alarm even in an area where the anti-theft tag does not want to generate an alarm (especially, a product display area in a store). The present invention has been made in view of the circumstances described above,
It is an object of the present invention to provide an anti-theft device capable of limiting an area for issuing an alarm.

[0004]

The anti-theft device according to the first invention is attached to an anti-theft object and outputs an alarm when its receiving circuit receives a predetermined signal continuously for a time T1. An anti-theft device comprising a tag and a transmitting circuit for outputting the predetermined signal, wherein T1> T2, T1
1> T3, time T2 satisfying the condition of T1 ≦ T2 + T3
T3, two types of transmitting circuits each outputting a predetermined signal, and synchronization for synchronizing the two types of transmitting circuits so that the two types of transmitting circuits alternately output the predetermined signals at times T2 and T3, respectively. Wherein the anti-theft tag is configured to output an alarm when predetermined signals output from the two types of transmission circuits are continuously received.

In this anti-theft device, the anti-theft tag is
An alarm is output when the receiving circuit is attached to the anti-theft object and the receiving circuit continuously receives a predetermined signal for a time T1.
A transmitting circuit outputs a predetermined signal. Two types of transmission circuits,
T1> T2, T1> T3, T1 ≦ T2 + T3 which satisfy the conditions of T2 + T3, respectively output predetermined signals, and the synchronizing circuit uses the two types of oscillators alternately for the times T2, T3,
In order to output a predetermined signal, the two types of transmission circuits are synchronized. The anti-theft tag outputs an alarm when the predetermined signals output by the two types of transmitting circuits are continuously received.

Accordingly, the anti-theft tag continuously outputs the predetermined signal for a time period during which the alarm can be issued only in the overlapping area of the respective areas where the predetermined signals transmitted by the two types of the anti-theft gates respectively reach. As a result, it is possible to realize an anti-theft device capable of limiting an area where an alarm is issued.

According to a second aspect of the present invention, there is provided an anti-theft device for transmitting a first signal, and a theft which is attached to an object to be stolen and outputs a second signal in response to the first signal output by the transmitting circuit. An anti-theft device comprising an anti-theft tag and an alarm circuit for outputting an alarm when the second signal output by the anti-theft tag is continuously received for a time T1.
> T2, T1> T3, T1 ≦ T2 + T3, T2 and T3, respectively, two types of transmitting circuits each outputting the first signal, and the two types of transmitting circuits alternately perform the time T
2, T3, and a synchronizing circuit for synchronizing the two types of transmitting circuits so as to output a first signal, respectively, wherein the alarm circuit includes a first signal from the two types of transmitting circuits. When the second signal output according to is received,
It is characterized by outputting an alarm.

In this anti-theft device, the transmitting circuit outputs a first signal, the anti-theft tag is attached to the anti-theft object, and outputs a second signal in response to the first signal output by the transmitting circuit. The alarm circuit outputs an alarm when the second signal output by the anti-theft tag is continuously received for a time T1. T1> T2, T1> T3, T
Times T2 and T3 satisfying the condition of 1 ≦ T2 + T3 respectively output a first signal, and the synchronous circuit outputs two kinds of signals so that the two kinds of transmitting circuits alternately output the first signals respectively at times T2 and T3. Synchronize the oscillator. The alarm circuit outputs an alarm when the anti-theft tag receives the second signal output in response to the first signal from the two types of transmission circuits.

[0009] Thus, only in the overlapping portion of the respective areas where the predetermined signals transmitted by the two types of anti-theft gates reach, the anti-theft tag operates continuously for a time during which the alarm circuit can issue an alarm. It is possible to output another predetermined signal according to the predetermined signal,
It is possible to realize an anti-theft device capable of limiting an area for issuing an alarm.

The antitheft device according to the third invention is characterized in that the times T2 and T3 are equal.

In this antitheft device, since the times T2 and T3 are equal, it is easy for the synchronization circuit to synchronize.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below.
This will be described with reference to the drawings showing the above. Embodiment 1 FIG. FIG. 1 is a circuit diagram showing a main part configuration of two types of anti-theft gates according to a first embodiment of the anti-theft device according to the present invention. These two types of anti-theft gate TX
a and TXb denote an oscillator 10 and a frequency dividing circuit 11 for dividing a periodic signal output from the oscillator 10 into a predetermined signal having a predetermined period.
And a predetermined signal obtained by dividing the frequency by the frequency dividing circuit 11. The transmitting circuits 13 and 14 repeat transmission / stop of transmission of the predetermined signal from the loop coils 15 and 16 every 50 msec (time T2 and T3). And a synchronizing circuit 12 for synchronizing the transmitting circuits 13 and 14 so that the frequency dividing circuit 11 is supplied with a predetermined signal and the transmitting circuits 13 and 14 alternately perform transmitting / receiving. I have. The oscillator 10, the frequency dividing circuit 11 and the synchronizing circuit 12 need only be provided in one of the two types of theft prevention gates TXa and TXb.

FIG. 2 is a perspective view showing the appearance of the anti-theft gate. The anti-theft gate is provided with a case 17 for accommodating the oscillator 10, the frequency dividing circuit 11, the synchronizing circuit 12, and the transmitting circuits 13 and 14 at a lower portion, and a rectangular frame 18 at an upper portion.
Are provided, and loop coils 15, 16 are provided in the hollow portion of the frame 18.
Is stored. There is a case 17 in which the oscillator 10, the frequency divider 11 and the synchronization circuit 12 are not housed. As shown in FIG.
An area C where the areas A and B where the predetermined signals transmitted by each of the anti-theft gates TXa and TXb reach reach C
Is installed between the two anti-theft gates.

FIG. 4 is a block diagram showing a configuration of a main part of an anti-theft tag in the anti-theft device according to the first embodiment of the present invention. This anti-theft tag T is an anti-theft gate TX
a, a receiving circuit 20 for receiving a predetermined signal from TXb,
A timer 21, an alarm display unit 22 including a light-emitting diode or the like for displaying that an alarm is being issued, a buzzer 23 for issuing an alarm, and a wire or a wire for detecting attachment / detachment to / from a product. An attachment / removal detection circuit 24 including pins and the like, a reset circuit 26 for resetting a state in which an alarm can be issued and an alarm state, an above-described receiving circuit 20, a timer 21, and an alarm display unit 22, a buzzer 23, an attachment / detachment detection circuit 24, and a reset circuit 26, each of which is provided with a microprocessor 27 for transmitting and receiving signals to and from them.

Hereinafter, the operation of the anti-theft device having the anti-theft gates TXa and TXb and the anti-theft tag T having such a configuration will be described with reference to the timing chart of FIG. 5 and the flowchart of FIG. explain. As shown in FIGS. 5A and 5B, the transmission circuits 13 and 14 of the two types of anti-theft gates TXa and TXb are alternately controlled, for example, every 50 msec, as shown in FIGS. A predetermined signal is output from the loop coils 15 and 16 to form areas A, B and C (FIG. 3).

The anti-theft tag T emits an alarm, for example, when a predetermined signal is received continuously for 100 ms (time T1 = approximately 100 ms to 51 ms). When the predetermined signal is received (S2), the timer 21 starts counting time (S4). Until 100 ms (predetermined time) elapses (S8), and when the predetermined signal is not received (S6), the timer 21 starts counting. Is reset (S16). Accordingly, when the anti-theft tag T enters the area A or B (FIG. 3), the predetermined signal is continuously received for only 50 msec, and therefore, no alarm is issued.

When the anti-theft tag T enters the area C (FIG. 3), a predetermined signal is output from the loop coils 15 and 16 of the two types of anti-theft gates TXa and TXb as shown in FIG. Is alternately addressed to 50 ms.
Until 0 ms (predetermined time) elapses (S8), the reception of the predetermined signal is continued (S6). As a result, the anti-theft tag T
Causes the buzzer 23 to sound and the alarm display section 22 to blink, and issues an alarm (S10). This alarm is issued until reset by the reset circuit 26 (S12).
When the anti-theft tag T is reset by the reset circuit 26 (S12), the timer 21 is reset (S1).
4) Stop issuing the alarm (S15).

FIG. 7 shows the above-described anti-theft gate TX.
FIG. 2 is an explanatory diagram for describing a main configuration of a first embodiment of an anti-theft device including a, TXb and an anti-theft tag T;
In this anti-theft device, the self-sounding anti-theft tag T described above is attached to a button hole of a relatively expensive anti-theft object (commodity) such as a jacket at a store in a store. (CA). The self-sounding anti-theft tag T
As described above, when a predetermined signal from the anti-theft gates TXa and TXb is alternately received, the buzzer 23 sounds and the alarm display section 22 flashes to issue an alarm.
If a wire or a pin of the attachment / detachment detection circuit 24 is removed without performing a reset process by the reset circuit 26, an alarm is issued.

At the cash register near the exit of the counter, a table-top type master remote control key TRK is installed. Simply by placing a product on the master remote control key TRK, the reset circuit 26 is reset, and a self-sounding theft prevention device is provided. The tag T changes from the set mode to the reset mode.
The self-sounding anti-theft tag T is removed from the product after entering the reset mode (CB). The self-sounding anti-theft tag T is set by the remote control key RK when attached to a product (CC).

Embodiment 2 FIG. 8 is a circuit diagram showing a main part configuration of two types of anti-theft gates according to the second embodiment of the anti-theft device of the present invention. 3 consisting of these two types
The anti-theft gates TXe, TXf, TXg include an oscillator 30, a frequency dividing circuit 31 for dividing the periodic signal output from the oscillator 30 into a predetermined signal of a predetermined period, and a predetermined frequency divided by the frequency dividing circuit 31. A signal is given, for example, every 50 ms (time T2, T3), the loop coil 36, 3 of the predetermined signal.
Transmission circuit 3 that repeats transmission / stop of transmission from 7, 38
3, 34, and 35, and a predetermined signal obtained by dividing the frequency of the frequency dividing circuit 31. The transmitting circuits 33, 35 are so arranged that the transmitting circuits 33, 35 and the transmitting circuit 34 alternately perform transmission / transmission stop.
And a synchronizing circuit 32 for synchronizing with the transmitting circuit. Note that the oscillator 30, the frequency dividing circuit 31, and the synchronizing circuit 32
May be provided in any of the theft prevention gates TXe, TXf, TXg.

Gates TXe, TXf, TXg for theft prevention
Is similar to the perspective view of FIG. 2 described above. As shown in FIG.
One of the three anti-theft gates TXe, TXf, TXg is an area G, H where two areas D, E, F, each of which receives a predetermined signal transmitted therefrom, are of the three anti-theft gates TXe, TXf, TXg. It is installed so as to be formed between them. The configuration of the main part of the anti-theft tag T according to the second embodiment is the same as the above-described block diagram of FIG.

Hereinafter, the operation of the anti-theft device having the anti-theft gates TXa and TXb and the anti-theft tag T having such a configuration will be described with reference to the timing chart of FIG. The transmission circuits 33, 35 and 34 of the two types of theft prevention gates TXe, TXg and TXf are controlled by the phase control from the synchronization circuit 32, as shown in FIGS. For example, a predetermined signal is alternately output every 50 msec.
6, 38 and 37 to form areas D to H (FIG. 9).

The anti-theft tag T emits an alarm, for example, when a predetermined signal is received continuously for 100 ms (time T1 = approximately 100 ms to 51 ms). If the predetermined signal is not received before 100 ms (predetermined time) elapses after the predetermined signal is received, reset is performed. Therefore, the anti-theft tag T
When entering the area D, E, or F (FIG. 9), the predetermined signal is continuously received for only 50 msec, so that no alarm is issued.

When the anti-theft tag T enters the area G or H (FIG. 9), two types of anti-theft gates TXe,
As shown in FIG. 10D, a predetermined signal is alternately received for 50 msec from the TXf or the TXf, TXg loop coil 36, 37 or 37, 38, so that 100 msec (predetermined time) elapses. , And continues to receive the predetermined signal.
As a result, the anti-theft tag T issues an alarm, and the alarm is issued until reset. The anti-theft tag T
When reset, the alarm stops. Other configurations and operations are the same as the configurations and operations described in the first embodiment, and a description thereof will not be repeated. However, the two anti-theft gates TXa, TXb in FIG. 7 are three anti-theft gates TXe, TXf,
TXg.

Embodiment 3 FIG. 11 is an explanatory diagram for explaining a main configuration of the anti-theft device according to Embodiment 3 of the present invention. The anti-theft device includes anti-theft gates TXc and TXd for outputting a predetermined radio signal (first signal).
And a resonance circuit, which is attached to the product and includes L and C inside, and the resonance circuit resonates with a radio signal of a predetermined frequency output by the anti-theft gates TXc and TXd. (A second signal). The anti-theft gates TXc and TXd alternately transmit radio signals for the same time (time T2, T3), similarly to the anti-theft gates TXa and TXb in the first embodiment. The radio signal transmitted by the resonance circuit of the resonance type paper tag PT is received by the receivers ALc and ALd (alarm means) attached to the anti-theft gates TXc and TXd, respectively.

FIG. 12 is a block diagram showing a configuration example of the receivers ALc and ALd. This receiver ALc, ALd
A reception circuit 41 for receiving a radio signal (second signal) from the resonance type paper tag PT, a timer 40, an alarm display unit 42 including a light emitting diode or the like for displaying that an alarm is being issued, Buzzer 43 for issuing an alarm
A reset circuit 44 for resetting a state in which an alarm can be issued and a state in which an alarm is issued; the above-described receiving circuit 41, timer 40, alarm display section 42, buzzer 4
3 and a reset circuit 44. The microprocessor 45 includes a microprocessor 45 for transmitting and receiving signals to and from them and controlling them.

The operation of the anti-theft device including the anti-theft gates TXc and TXd, the receivers ALc and ALd, and the resonance type paper tag PT having the above-described configuration will be described below with reference to the timing chart of FIG. This will be described with reference to the flowchart of FIG. The two types of anti-theft gates TXc and TXd operate in the same manner as the anti-theft gates TXa and TXb in the first embodiment, and FIG.
As shown in (b), radio signals of a predetermined period are output alternately for the same time to form areas A, B and C (FIG. 3). Resonant paper tag PT is a gate TX for theft prevention
The resonance circuit resonates with a radio signal from c and TXd, and outputs a radio signal due to the resonance.

The receivers ALc and ALd have a time shorter than the sum of the times when the anti-theft gates TXc and TXd alternately output radio waves (time T2 and T3) and longer than the time when each radio wave is output. When a radio signal output from the resonance type paper tag PT is received continuously for a time (time T1), an alarm is issued, and when a radio signal from the resonance type paper tag PT is received (S
20) The timer 40 is started to measure time (S24). If no radio signal is received until the time T1 elapses (S28), the timer 40 is reset (S36). Accordingly, when the resonance type paper tag PT enters the area A or B (FIG. 3), the radio signal from the resonance type paper tag PT is shorter than the time T1, so that no alarm is issued.

When the resonance type paper tag PT enters the area C (FIG. 3), two types of theft prevention gates TXc,
Since the radio signal is alternately received from TXd as shown in FIG. 5C, the radio signal due to resonance is continuously transmitted until the time T1 (predetermined time) elapses. For this reason, the receivers ALc and ALd continue to receive the radio signal due to resonance until the time T1 (predetermined time) elapses (S28) (S28).
26). As a result, the receivers ALc and ALd output the buzzer 4
3 is sounded, the alarm display section 42 is made to blink, and an alarm is issued (S30). This alarm is issued until reset by the reset circuit 44 (S32). Receiver AL
When c and ALd are reset by the reset circuit 44 (S32), the timer 40 is reset (S3).
4) Stop issuing the alarm (S35).

Referring to FIG. 11, the anti-theft device is used in a store in a store, in which the above-described resonant paper tag P is used.
T is attached to a relatively inexpensive anti-theft object (commodity) such as a sock and a handkerchief (CA). As described above, the resonance type paper tag PT continuously transmits a radio wave signal due to resonance when alternately receiving a radio wave signal from the anti-theft gates TXc and TXd, and the receiver A
Lc and ALd issue an alarm when the radio signal is received for a time longer than the time T1. When a product to which the resonance type paper tag PT is attached is sold, the resonance circuit has a gate TXc, TXd for preventing theft at a cash register when the product is sold.
(E.g., electromagnetic shield) so as not to resonate with a radio signal from the computer (CB). In the claims,
For convenience of comparison with the drawings, reference numerals are given, but the present invention is not limited to the structure of the accompanying drawings.

[0031]

According to the antitheft device of the first invention,
Only in the overlapping areas of the respective areas where the predetermined signals transmitted by the two types of anti-theft gates reach,
The anti-theft tag can receive a predetermined signal continuously for a time during which an alarm can be issued, thereby realizing an anti-theft device capable of limiting an area where an alarm is issued.

According to the anti-theft device according to the second invention, 2
Only in the overlapping areas of the respective areas where the predetermined signals transmitted by the anti-theft gates of each type reach, the anti-theft tag can be used in response to the predetermined signals for another period of time during which the alarm circuit can issue an alarm. As a result, a predetermined signal can be output, and an anti-theft device that can limit an area where an alarm is issued can be realized.

According to the anti-theft device according to the third invention, since the times T2 and T3 are equal, it is easy for the synchronization circuit to synchronize.

[Brief description of the drawings]

FIG. 1 shows an embodiment 2 of the anti-theft device according to the present invention.
It is a circuit diagram which shows the principal part structure of the type anti-theft gate.

FIG. 2 is a perspective view showing an appearance of an anti-theft gate.

FIG. 3 is an explanatory diagram for explaining the operation of the anti-theft gate of the anti-theft device according to the present invention.

FIG. 4 is a block diagram showing a main configuration of an anti-theft tag of the anti-theft device according to the present invention.

FIG. 5 is a timing chart showing the operation of the antitheft device according to the present invention.

FIG. 6 is a flowchart showing the operation of the anti-theft tag of the anti-theft device according to the present invention.

FIG. 7 is an explanatory diagram for explaining a main configuration of the anti-theft device according to the present invention.

FIG. 8 shows a second embodiment of the antitheft device according to the present invention;
It is a circuit diagram which shows the principal part structure of the anti-theft gate of a kind.

FIG. 9 is an explanatory diagram for explaining the operation of the anti-theft gate of the anti-theft device according to the present invention.

FIG. 10 is a timing chart showing the operation of the antitheft device according to the present invention.

FIG. 11 is an explanatory diagram for explaining a main configuration of an anti-theft device according to the present invention.

FIG. 12 is a block diagram showing a main configuration of a receiver of the anti-theft device according to the present invention.

FIG. 13 is a flowchart showing the operation of the receiver of the anti-theft device according to the present invention.

[Explanation of symbols]

 12, 32 Synchronous circuit 13, 14, 33-35 Transmitting circuit 15, 16, 36-38 Loop coil 21, 40 Timer 23, 43 Buzzer ALc, ALd Receiver (alarm circuit) PT Resonant paper tag (anti-theft tag) T Anti-theft tag TXa-TXg Anti-theft gate

Claims (3)

[Claims] 1. An anti-theft tag (T) which is attached to an anti-theft object and outputs an alarm when the receiving circuit (20) receives a predetermined signal continuously for a time T1; and outputs the predetermined signal. A transmission circuit (13, 14) that outputs a predetermined signal at times T2, T3 satisfying the condition of T1> T2, T1> T3, T1 ≦ T2 + T3, respectively. 14) and the two types of transmitting circuits (13, 14) alternately output the predetermined signal at times T2, T3, respectively.
3, 14) and a synchronization circuit (12) for synchronizing the two types of transmission circuits (1).
An anti-theft device, which outputs an alarm when the predetermined signals respectively output by the third and fourth aspects are continuously received. 2. An oscillator circuit for outputting a first signal.
4) an anti-theft tag (PT) attached to the anti-theft object and outputting a second signal in response to the first signal output by the transmission circuit (13, 14);
An alarm circuit (ALc, ALd) for outputting an alarm when the second signal output by T) is continuously received for a time period T1, wherein T1> T2, T1> T3, and T1 ≦ T2 + T3. Times T2 and T3 satisfying the condition, two types of transmission circuits (13 and 14) for outputting the first signal, respectively, and the two types of transmission circuits (13 and 14) are alternately time T2 and T3, respectively. In order to output one signal, the two types of transmission circuits (13,
14) and a synchronization circuit (12) for synchronizing, the alarm circuit (ALc, ALd) includes the anti-theft tag (P
T) is the first of the two types of transmission circuits (13, 14).
An anti-theft device that outputs an alarm when a second signal output in response to the signal is received. 3. The anti-theft device according to claim 1, wherein the times T2 and T3 are equal.