JP3531031B2 - Anti-theft tag and anti-theft device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a mounting state and a detaching state with respect to an antitheft object, and when the detached state is detected and a predetermined signal is received,
The present invention relates to an anti-theft tag that outputs an alarm and an anti-theft device.

[0002]

2. Description of the Related Art An anti-theft tag is attached to a product which is an anti-theft object, so that a person does not have to take measures such as removing it.
The gate or the tag itself outputs an alarm when the product is taken out from the gate provided near the exit of the store. The anti-theft tag has a self-sounding type that outputs an alarm when the attachment state and the detachment state of the product are detected, and when the detachment state is detected and a predetermined signal is received from the gate, and L and C inside. It has a resonance circuit consisting of, and is attached to the product, the resonance circuit resonates with a radio wave of a predetermined frequency from the gate, and the gate
There is a resonance type paper tag that outputs an alarm when a radio wave transmitted by a resonance circuit is received due to the resonance.

A conventional self-sounding type anti-theft tag receives only a predetermined signal from its dedicated gate and outputs an alarm. On the other hand, in the resonance type paper tag, the gate for the resonance type paper tag eliminates the influence of the resonance frequency shift (due to temperature, humidity, etc.) of the resonance type paper tag, and transmits the radio wave from the resonance frequency to the center frequency of the nominal resonance frequency. As shown in FIG. 3, the sweep is performed substantially periodically. In some resonance type paper tags, the gate transmits the transmitted radio waves in a burst shape with the nominal resonance frequency as the center frequency, and the radio waves emitted by the resonance circuit of the resonance type paper tag during the non-transmission period. Trying to receive.

[0004]

Since the self-sounding anti-theft tag can issue an alarm even when it is removed, and is relatively expensive, it is used for expensive goods and is a resonance type paper tag. Cannot be detected even if peeled off, and
Since they are cheap, they are used for cheap products, but when they are used at the same place, their dedicated gates (transmission / reception means) are required. If you want to use both with the same dedicated gate, for example, if you want to use a self-sounding anti-theft tag with a dedicated gate of a resonance type paper tag, install a single tuning circuit inside the self-sounding anti-theft tag to resonate. Even if the frequency modulation signal (sweep signal) or burst signal transmitted by the dedicated gate of the paper tag is tuned, it is possible to obtain sufficient reception sensitivity compared to the case where the continuous signal of a single frequency is tuned. I can't.

In order to obtain sufficient reception sensitivity, it is necessary to increase the reception gain, but if the reception gain is increased, the reception gain of radio waves (noise) from the external inverter other than the gate, the mobile phone, etc. also increases. There is a problem that malfunctions are likely to occur. The present invention has been made in view of the above-mentioned circumstances, and has a high reception sensitivity of a signal transmitted by a dedicated gate of a resonance-type paper tag and has a good noise resistance, and a self-sounding anti-theft tag and its theft. An object of the present invention is to provide an anti-theft device equipped with an anti-theft tag.

[0006]

A theft prevention tag according to a first aspect of the present invention detects an attachment state and a removal state with respect to an antitheft object, and outputs an alarm when the removal state is detected and when a predetermined signal is received. In an anti-theft tag that outputs, a tuning circuit that tunes to a received signal of a first frequency that is made into a sweep signal or a burst signal for causing a resonance-type paper tag for anti-theft to resonate, and reception that the tuning circuit tunes to and amplifying detector circuit for amplifying the signal detection, the frequency of the amplification detection circuit amplifies detected signal, the sweep signal
Signal sweep frequency or burst frequency of the burst signal
A frequency discriminating means for discriminating whether or not it matches a second frequency which is a number, and an alarm output for outputting an alarm when the frequency discriminating means discriminates that the frequency of the signal matches the second frequency. And means.

[0007] In this anti-theft tag, tuning circuit, the sweep signal for resonating the resonant paper tag for theft prevention
Alternatively , the amplification detection circuit amplifies and detects the reception signal tuned by the tuning circuit, which is tuned to the reception signal of the first frequency converted into the burst signal . The frequency discrimination means is such that the frequency of the signal amplified and detected by the amplification detection circuit is the sweep frequency of the sweep signal.
When the frequency discriminating means discriminates whether or not it matches (generally coincides with) the second frequency which is the wave number or the burst frequency of the burst-like signal, and the frequency discriminating means discriminates that the frequency of the signal matches the second frequency. The alarm output means outputs an alarm. As a result, the reception sensitivity of the signal transmitted by the dedicated gate of the resonance type paper tag is improved, the noise resistance is improved, and even the self-sounding anti-theft tag can be used in the dedicated gate of the resonance type paper tag.

In the theft prevention tag according to the second aspect of the invention, the frequency discriminating means divides the frequency of the signal amplified and detected by the amplification detection circuit by 1 / n (n is an integer), and the frequency division circuit. Cycle determining means for determining whether or not the cycle of the signal divided by the frequency divider circuit by 1 / n matches the cycle corresponding to the frequency of 1 / n of the second frequency; It is determined whether or not the matching is continuously determined a predetermined number of times, and when the matching is continuously determined a predetermined number of times, a determination signal is given to the alarm output means.

In this anti-theft tag, the frequency dividing circuit divides the frequency of the signal amplified and detected by the amplification detecting circuit by 1 / n, and the period determining means determines the frequency of the signal divided by the frequency dividing circuit by 1 / n. It is determined whether or not the cycle matches (generally matches) the cycle corresponding to the frequency of 1 / n of the second frequency. The judging means is
The cycle determination means determines whether or not it is determined that the cycle is continuously matched a predetermined number of times, and when it is determined that the cycle is continuously matched a predetermined number of times, a predetermined signal is given to the alarm output means.
As a result, the reception sensitivity of the signal transmitted by the dedicated gate of the resonance type paper tag is improved, the noise resistance is improved, and even the self-sounding anti-theft tag can be used in the dedicated gate of the resonance type paper tag.

A theft prevention device according to a third aspect of the present invention is defined in claim 1.
Alternatively, the anti-theft tag described in 2, the resonance-type paper tag for theft prevention, and radio waves for causing the resonance-type paper tag to resonate are emitted substantially periodically to detect that the resonance-type paper tag resonates. The anti-theft gate is provided with alarm output means for outputting an alarm when the anti-theft gate detects that the resonant paper tag resonates.

In this theft prevention device, the antitheft tag according to claim 1 or 2, the resonance type paper tag for theft prevention, and the electric wave for causing the resonance type paper tag to resonate are emitted substantially periodically to cause resonance. Since the anti-theft gate that detects that the shaped paper tag has resonated and the anti-theft gate has an alarm output unit that outputs an alarm when it detects that the resonant paper tag has resonated, Both self-sounding anti-theft tags and resonant paper tags can be used with one type of gate.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
It will be described with reference to the drawings showing the same. Embodiment 1. FIG. 1 is a block diagram showing a main part configuration of an embodiment of an anti-theft tag according to the present invention. This anti-theft tag includes a single tuning circuit 1 that tunes to a received signal having a frequency for resonating a resonant paper tag, and an amplification detection circuit 2 that amplifies and detects the received signal tuned by the single tuning circuit 1. I have it. The single tuning circuit 1 tunes to an intermediate frequency of a swept signal or burst signal having a constant frequency band as shown in FIG.

In this theft prevention tag, the frequency of the signal amplified and detected by the amplification detection circuit 2 is the same as the above-mentioned sweep frequency of the sweep signal or the burst frequency of the burst-like signal for resonating the resonance type paper tag. Match (generally agree)
A frequency discriminating circuit 3 (frequency discriminating means) for discriminating whether or not to perform an alarm signal generation for generating an alarm signal when the frequency discriminating circuit 3 discriminates that the frequency of the signal matches the sweep frequency or the burst frequency. and circuit 4, and a speaker 5 (alarm output means) alarm signal generating circuit 4 (alarm output means) outputs an alarm signal generated.

FIG. 2 is a block diagram showing a configuration example of the frequency discrimination circuit 3, which is an implementation example using a monostable multivibrator. The frequency discriminating circuit 3 divides the signal amplified and detected by the amplification detecting circuit 2 into 1/2 (n = 2),
1/2 divider circuit 6 that shapes and outputs a square wave, and 1/2
The monostable multivibrators 7 and 8 (cycle determining means) to which the signal output from the frequency dividing circuit 6 is given, and the output terminal Q of the monostable multivibrator 7 are connected to the signal input terminal Sin and the bar reset terminal bar Reset. Shift register 9 and output terminals QA to Q of shift register 9
N is connected to each input terminal, and the output of the AND circuit 10 is given to the alarm signal generating circuit 4.

The shift register 9 and the logical product circuit 10 (determining means) are such that the periods of the signals input to the monostable multivibrators 7 and 8 correspond to the above-mentioned sweep frequency or half the burst frequency. The number of times determined to match (generally match) the cycle is the predetermined number (N) of the cycle
It is determined whether or not they continue.

Output terminal Q of monostable multivibrator 7
Is connected to the bar reset terminal bar Reset of the monostable multivibrator 8.
The inverting output terminal Q of is connected to the clock terminal CLK of the shift register 9. The monostable multivibrators 7 and 8 are retriggerable monostable multivibrators that are triggered at the rising edge of the input signal and are once triggered and retriggered at the rising edge of the input signal even within the pulse width time.

The monostable multivibrator 7 has a cycle (corresponding to the lower limit frequency of the frequency range (the sweep frequency and the burst frequency are not always constant) for discriminating the above-mentioned sweep frequency or 1/2 frequency of the burst frequency ( Therefore, it has a pulse width of the longest period). The monostable multivibrator 8 has a pulse width of a cycle (hence, the shortest cycle) corresponding to the upper limit frequency of the frequency range for discriminating the above-mentioned sweep frequency or 1/2 frequency of the burst frequency. The frequency discriminating circuit 3 and the alarm signal generating circuit 4 may be caused to perform the same signal processing as the above-mentioned signal processing by a microcomputer or a custom IC.

The operation of the anti-theft tag having such a structure will be described below with reference to the timing chart shown in FIG. The received signal tuned by the single tuning circuit 1 is amplified and detected by the amplification detection circuit 2. The signal detected by the amplification detection circuit 2 is given to the frequency discriminating circuit 3, and the frequency discriminating circuit 3 sweeps the above-mentioned sweep signal so that the frequency of the given signal resonates the resonance type paper tag. Discriminate whether or not it matches the frequency or the burst frequency of the burst-like signal.

The 1/2 frequency dividing circuit 6 of the frequency discriminating circuit 3 is
The signal detected and amplified by the amplification detection circuit 2 is divided into 1/2,
It is shaped into a square wave and given to the monostable multivibrators 7 and 8. The monostable multivibrator 7 is used when the period of a given square wave is shorter than its pulse width (see FIG. 4A).
(A)), continuously outputs an H level signal (b), and supplies it to each bar reset terminal bar Reset of the monostable multivibrator 8 and the shift register 9 to operate the monostable multivibrator 8 and the shift register 9, respectively. Enable it.

When the period of the given square wave is longer than its pulse width (FIG. 4A (a)), the monostable multivibrator 8 is self-triggered even if it is triggered and the output signal becomes H level. Each time the pulse width period elapses, the output signal returns to L level (c), and the rising signal output from the inverting output terminal bar Q at this time becomes the clock of the shift register 9 (d). This clock shifts the data stored in the shift register 9. Therefore, the period of the given square wave is continuously shorter than the pulse width of the monostable multivibrator 7, and the monostable multivibrator 8 is
If the pulse width is longer than the pulse width of, the stored data in the shift register 9 continuously becomes H level, and when this continues N times, all the output signals of the output terminals QA to QN become H level, and the AND circuit 10. Gives an H level signal to the alarm signal generating circuit 4. The alarm signal generation circuit 4, when given an H level signal, generates an alarm signal and outputs it from the speaker 5.

When the period of the given square wave is longer than its pulse width (FIG. 4B (a)), the monostable multivibrator 7 has its own output even if it is triggered and its output signal becomes H level. Each time the pulse width period elapses, the signal returns to the L level (b), the L level signal is given to each bar reset terminal bar Reset of the monostable multivibrator 8 and the shift register 9, and the monostable multivibrator 8 and the shift register 9 are turned on. Reset to inoperable state. Therefore, when the period of the given square wave is longer than the pulse width of the monostable multivibrator 7, the shift register 9 does not operate, the AND circuit 10 does not give the H level signal to the alarm signal generating circuit 4, The alarm signal generation circuit 4 does not generate an alarm signal.

The monostable multivibrator 7 continuously outputs an H level signal (b) when the period of the given square wave is shorter than its pulse width (FIG. 4C (a)).
The monostable multivibrator 8 and the shift register 9 are applied to the respective bar reset terminals Bar Reset to enable the monostable multivibrator 8 and the shift register 9 respectively.

When the period of the given square wave is shorter than its pulse width (FIG. 4C (a)), the monostable multivibrator 8 continuously outputs the H level signal and returns to the L level. No (c), the clock of the shift register 9 is not output from the inverting output terminal bar Q (d). Therefore, the given square wave period is equal to the monostable multivibrator 8
If the pulse width is shorter than the pulse width, the storage data in the shift register 9 is not shifted, the AND circuit 10 does not give the H level signal to the alarm signal generating circuit 4, and the alarm signal generating circuit 4 does not generate the alarm signal.

From the above, the frequency discriminating circuit 3 determines the lower limit of the frequency range for discriminating the above-mentioned sweep frequency or 1/2 frequency of the burst frequency with the period of the given square wave continuously given N times. When it is shorter than the cycle corresponding to the frequency (hence the longest cycle) and longer than the cycle corresponding to the upper limit frequency (hence the shortest cycle), the H level signal is given to the alarm signal generating circuit 4. As a result, the alarm signal generation circuit 4 generates an alarm signal and outputs it from the speaker 5.

Embodiment 2. FIG. 5 is an explanatory diagram for explaining a main part configuration of an embodiment of an anti-theft device according to the present invention. In this anti-theft device, the self-sounding anti-theft tag T described in the first embodiment is entangled in a button hole or the like of a relatively expensive anti-theft object (product) such as a jacket in a store floor of a store. The resonating paper tag PT is attached to a relatively inexpensive product such as a sock and a handkerchief directly or on its packaging bag (A).

The resonance type paper tag PT has a resonance circuit, and the resonance circuit resonates with a radio wave of a predetermined frequency from a gate TX provided near the entrance of the sales floor, and the gate TX is
When the electric wave transmitted from the resonance circuit is received by the resonance, the alarm device AL (alarm output means) provided around the gate TX outputs an alarm. The self-sounding anti-theft tag T
When receiving a radio wave of a predetermined frequency from the gate TX and discriminating that the received radio wave signal is a radio wave signal of the predetermined frequency from the gate TX, an alarm is output from the built-in alarm device.

A desk-type master remote control key TRK is installed at the cashier near the exit of this sales floor, and a self-sounding anti-theft tag T can be switched from the set mode to the reset mode by simply placing a product on it. It is supposed to be. The self-sounding anti-theft tag T is removed from the product after entering the reset mode (B). The product to which the resonance type paper tag PT is attached is treated (electromagnetic shield or the like) so that the resonance circuit of the resonance type paper tag PT does not resonate at the cash register at the time of sale (B). The self-sounding anti-theft tag T is set by the remote control key when attached to the product (C). The resonance type paper tag PT is in a set state as it is and attached to the product.

[0028]

According to the anti-theft tag of the present invention, the reception sensitivity of the signal transmitted by the dedicated gate of the resonance type paper tag is improved, the noise resistance is improved, and even the self-sounding anti-theft tag is resonated. It can be used with the dedicated gate of the shape paper tag.

According to the antitheft device of the present invention, both the self-sounding antitheft tag and the resonance type paper tag can be used in one type of gate.

[Brief description of drawings]

FIG. 1 is a block diagram showing a main part configuration of an embodiment of an anti-theft tag according to the present invention.

FIG. 2 is a block diagram showing a configuration example of a frequency discrimination circuit.

FIG. 3 is a waveform diagram for explaining the concept of transmission radio waves swept by a resonance type paper tag gate.

FIG. 4 is a timing chart showing the operation of the anti-theft tag.

FIG. 5 is an explanatory diagram for explaining a main part configuration of an embodiment of an anti-theft device according to the present invention.

[Explanation of symbols] 1 Single tuning circuit 2 amplification detection circuit 3 Frequency discrimination circuit (frequency discrimination means) 4 Alarm signal generation circuit (alarm output means) 5 speakers 6 1/2 divider circuit (divider circuit) 7,8 Monostable multivibrator (cycle determination means) 9 shift register (determination means) 10 AND circuit AL alarm (alarm output means) PT Resonant Paper Tag T anti-theft tag TRK Desktop type master remote control key

Claims (3)

(57) [Claims] 1. A resonance type anti-theft paper for an anti-theft tag, which detects an attachment state and a detached state of an anti-theft object and outputs an alarm when the detached state is detected and when a predetermined signal is received. Sweep to resonate the tag
A tuning circuit that tunes to a received signal of a first frequency converted into a signal or a burst signal, an amplification detection circuit that amplifies and detects a reception signal that is tuned by the tuning circuit, and a signal that the amplification detection circuit amplifies and detects. The frequency of is the sweep frequency of the sweep signal
A frequency discriminating means for discriminating whether or not it matches with a second frequency which is a wave number or a burst frequency of the burst-like signal , and the frequency discriminating means discriminates that the frequency of the signal matches the second frequency. An anti-theft tag, further comprising alarm output means for outputting an alarm. 2. The frequency discriminating means divides the frequency of the signal amplified and detected by the amplification detection circuit by 1 / n (n
Is a integer) and a cycle determining means for determining whether or not the cycle of the signal divided by the frequency divider circuit by 1 / n matches the cycle corresponding to the frequency of 1 / n of the second frequency. And determining whether or not the cycle determining means determines that the cycle continues for a predetermined number of times, and when the cycle determining means determines that the cycle continues for a predetermined number of times, a predetermined signal is given to the alarm output means. The anti-theft tag according to claim 1, further comprising: 3. An anti-theft tag according to claim 1 or 2,
Anti-theft resonance type paper tag, an anti-theft gate that detects the resonance of the resonance type paper tag by transmitting a radio wave for causing the resonance type paper tag to resonate almost periodically, and the anti-theft Anti-theft device, characterized in that the gate for use has an alarm output means for outputting an alarm when it detects that the resonant paper tag has resonated.