JPH05225455A - Burglarproof device - Google Patents

Abstract

PURPOSE:To enable a clerk to surely recognize that a merchandise is stolen even if the level of the alarm tone leaked to the outside is low in the case the merchandise is hidden in a bag or the like and is going to be brought out of the shop. CONSTITUTION:When a merchandise is stolen, the multiple signal of plural frequency signals is generated as the alarm tone from an alarm device 15 built in a burglarproof device main body 13, and the clerk recognizes it by the alarm tone that the merchandise is stolen. The level of the alarm tone leaked to the outside is reduced when the merchandise is hidden in a bag or the like and is going to be brought out of the shop, but the gain of a detector 14 is raised to amplify and detect the attenuated alarm tone and the output state is switched only at the time of detecting that plural kinds of signal having preliminarily determined specific frequencies are included in the detected tone, therefore, the malfunction of the output circuit of the detector 14 due to the peripheral noise is avoided. Consequently, a warning lamp 25 for reporting the occurrence of an alarm is operated by the output circuit, thereby, the clerk recognizes it by the lamp 25 that the commodity is stolen.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-theft device attached to an in-store exhibit to protect a product from shoplifting.

[0002]

2. Description of the Related Art When using this type of device, a signal of a specific frequency f is radiated in the vicinity of the entrance / exit of a store, and the body of the anti-theft device has a sound generator 1 and a battery 2 as shown in FIG. The transistors 3 and 4 and the receiving circuit 5 are built in.

This anti-theft device body is attached to a product with a conductive tag code 6, and the anti-theft device body has a built-in transistor 7 for detecting that the tag code 6 has been illegally removed. ..

A specific method of attaching the tag code 6 to a product is, as described in Japanese Patent Laid-Open No. 2-14398, joining by snapping, pressing on an electrode by a pressing body, or sandwiching by a spring-like electrode. Is attached to the product by.

In this example, the transistor 7 detects conduction between the junction 8a and the junction 8b. Junction 8a
In the state where the tag code 6 is conductive between the junction 8b and the junction 8b, the collector potential of the transistor 7 is at "L" level.

The parallel resonance frequency of the coil 9 and the capacitor 10 of the receiving circuit 5 is set to a specific frequency f, and when a product attached with this anti-theft device is taken out of the store, it is near the entrance of the store. While the signal of the specific frequency f radiated to the coil is linked to the coil 9, the receiving circuit 5
Output voltage level rises, the transistor 4 turns on the base current of the transistor 3 during that period, and the battery 2 supplies power to the sounding device 1 via the transistor 3.

When the signal of the specific frequency f is not linked to the coil 9, the output voltage of the receiving circuit 5 is lowered and the transistor 4 is turned off. However, in the conventional case, the collector voltage of the transistor 3 is passed through the feedback resistor 11. Is applied to the base of the transistor 4, the transistor 4 is held in the ON state, and the sounding device 1 continues to ring.

When the tag code 6 is cut or the joint portions 8a and 8b are illegally removed in an attempt to remove the antitheft device attached to the product and take it out of the store, the transistor 7 of the transistor 7 is removed. Collector potential is "H"
Inverting to the level, the transistor 4 turns on the base current of the transistor 3 during that period, and power is supplied to the sounding device 1 from the battery 2 via the transistor 3. The alarm sound generated from the sounding device 1 was a single frequency signal as shown in FIG.

[0009]

When a theft occurs, the sounding device 1 built in the antitheft device main body attached to the stolen product operates to generate an alarm sound, but the shoplifting action is performed. When a person tries to get out of the store by hiding the body of the anti-theft device in a bag or the like, the level of the alarm sound leaking from the bag to the outside becomes small, and there is a problem that the clerk listens to the alarm sound.

According to the present invention, when the main body of the anti-theft device is hidden in a bag or the like and is to be taken out of the store, the clerk can be sure to recognize the occurrence of the theft even if the level of the alarm sound leaking to the outside is small. It is an object of the present invention to provide an antitheft device that can be used.

[0011]

The anti-theft device of the present invention is provided with a transmitter for radiating a signal of a specific frequency near the exit of a controlled area, which amplifies a detection sound and outputs a signal of a predetermined specific frequency. Anti-theft protection that is attached to the product to be protected by determining whether it is included in the detected sound, detecting the presence of multiple types of signals with a predetermined specific frequency, and switching the output circuit The device body has a separation detecting means for detecting that the anti-theft device body has been removed from the object to be protected, and a signal for separating the anti-theft device body from the object to be protected by the separation detecting means or a signal having a specific frequency. And an alarm device for generating a multiple signal of a plurality of frequency signals as an alarm sound in this set state.

[0012]

According to this structure, when a theft occurs, the alarm device incorporated in the body of the anti-theft device generates a multiple signal of a plurality of frequency signals as an alarm sound, and the clerk can recognize the occurrence of the theft from the alarm sound.

When the main body of the anti-theft device is hidden in a bag or the like and is going out of the store, the level of the alarm sound leaking to the outside is reduced, but the alarm sound is attenuated by increasing the gain of the detection device. Amplify and detect, and switch the output state of the detection device only when it detects that the detected sound contains multiple types of signals with a predetermined specific frequency. The output circuit of the device does not malfunction. Therefore, by operating the warning light for notifying the alarm occurrence and another alarm device by the output circuit of the detection device, the store clerk can recognize the occurrence of theft from the warning light and the alarm sound.

[0014]

Embodiments of the present invention will be described below with reference to FIGS. In addition, what has the same operation as in FIG.
Description will be given with the same reference numerals.

As shown in FIG. 1, the antitheft device of the present invention comprises a transmitter 12, an antitheft device body 13 and a detection device 14. The transmitter 12 has a transmission frequency of a specific frequency f, and radiates a signal only in the vicinity of the entrance / exit of the store where the article to be protected is placed. The anti-theft device body 14 is attached to the product with the tag code 6 as in the conventional case.

The alarm device 15 for generating an alarm sound is configured to generate a multiple signal of a plurality of frequency signals as an alarm sound, and the conventional sounding device 1 for generating an alarm sound of a single frequency.
And its configuration is different. Specifically, when the transistor 3 is turned on, the alarm device 15 turns on the alarm 100 shown in FIG.
The first signal S1 of Hz and the second signal S2 of 2 KHz shown in FIG. 2 (b) are multiplexed to create a third signal S3 shown in FIG. The third signal S3
Is pronounced as a sound wave.

The detection device 14 includes a microphone 17 arranged near the entrance and exit of the store, an amplifier 18 for amplifying the sound detected by the microphone 17, and first and second amplifiers connected to the output of the amplifier 18.
Synchronous filters 19 and 20 and the first and second synchronous filters 1
First and second match detection units 2 connected to the outputs of 9 and 20
1, 22 and an AND gate 23 that detects the logical product of the output of the first match detection unit 21 and the output of the second match detection unit 22,
It is composed of a transistor 24 which is switched by the output of the AND gate 23 and a warning lamp 25 which is turned on / off by the transistor 24. When the frequency of the first signal S1 included in the third signal S3 of the alarm sound is 100 Hz and the frequency of the second signal S2 is 2 KHz, the extracted frequency component of the first synchronous filter 19 is The frequency of the first signal S1 is set to 100 Hz, and the extraction frequency component of the second synchronous filter 20 is set to 2 KHz of the frequency of the second signal S2. When the signal level of the output of the first synchronous filter 19 is equal to or higher than the specified value, the first match detection unit 21 outputs H
When the signal level is inverted to a level below the specified value, the output returns to the L level. The second match detection unit 22 inverts the output to the H level when the signal level of the output of the second synchronous filter 20 is equal to or higher than the specified value, and turns the output to the L level when the signal level becomes less than the specified value. Return. Therefore, when the microphone 17 detects the third signal S3, the output of the AND gate 23 is inverted to the H level, the transistor 24 is turned on, and the warning lamp 25 is turned on.

With this configuration, when the anti-theft device body 13 is hidden in a bag or the like and the user tries to leave the store, the third signal S3, which is an alarm sound leaking from the bag to the outside, is output from the microphone 17. Detected by the amplifier 18, amplified to a required level by the amplifier 18, and the first and second synchronous filters 19,
The warning light 25 is switched on via 20. Here, although the amplification degree of the amplifier 18 is set to be large so that the attenuated alarm sound can be detected, the first and second synchronous filters 19 and 20 and the AND gate 23 are provided so that the frequency is 1
Since the warning light 25 is turned on only when both the first signal S1 of 00 Hz and the second signal S2 of frequency 2 KHz are included, ambient noise is detected and the warning light is erroneously operated.
Very few 25 lights.

Therefore, even if the alarm sound is attenuated to such a weak level that the clerk cannot hear it, the detection device 14 amplifies and detects it and turns on the warning light 25. The occurrence of theft can be recognized from the warning light 25.

Although the self-holding circuit in the detection device 14 is not described in detail in the above embodiment, when the output of the AND gate 23 is inverted to the H level, the output of the AND gate 23 is then set to the L level. It can be configured so that the warning light 25 continues to light up even after returning.

Although the warning light 25 is turned on / off by the output circuit of the detection device 14 in the above-mentioned embodiment, the occurrence of theft can be surely notified even if a device for generating an alarm on is connected instead of the warning light.

The alarm device 15 of the above embodiment multiplexes the first signal S1 of continuous signal and the second signal S2 of continuous signal to output the third signal S3 shown in FIG. 2 (c) as an alarm sound. I pronounced, but this is the same as the signal shown in Fig. 3 (a) (b).
The same is true when the tone burst signal is synthesized as shown in FIG.

In each of the above embodiments, the frequency of the first signal S1 was lower than that of the second signal S2.
The frequency of the signal S1 of the second signal S2 is higher than that of the second signal S2, or the second signal S2 is set to an audible frequency.
It is also possible to set the signal S1 of 1 to the ultrasonic frequency.

In each of the above embodiments, the alarm sound is composed of two frequency signals combined, but the alarm sound is composed of three or more frequency signals combined, and the detection device includes signals of three or more specific frequencies. The reliability is further improved by detecting that the output circuit is switched and switching the output circuit.

[0025]

As described above, according to the present invention, a transmitter for radiating a signal of a specific frequency is provided near the exit of a controlled area to amplify the detected sound and to output a signal of a predetermined specific frequency to the detected sound. A detection device is provided that determines whether or not it is included, detects that a plurality of types of signals of a predetermined specific frequency are included, and switches the output circuit.
The anti-theft device body attached to the product to be protected includes a separation detection unit that detects that the anti-theft device unit has been removed from the product to be protected, and a separation detection unit that separates the body of the anti-theft device from the product to be protected. Or it is set by detecting the signal of a specific frequency, and in this set state, an alarm device that generates a multiple signal of multiple frequency signals as an alarm sound is provided, so you can hide the anti-theft device main body in a bag etc. and leave the store In such a case, the level of the alarm sound leaking to the outside is reduced, but the gain of the detection device is increased and the attenuated alarm sound is amplified and detected, and the warning light and another alarm device are operated. By this, the clerk
The alarm sound can be used to recognize the occurrence of theft.

Further, the output circuit is switched only when the detection device detects that the detection sound includes a plurality of types of signals of a predetermined specific frequency, and therefore the output of the detection device is output due to ambient noise. The circuit is highly reliable and rarely malfunctions.

[Brief description of drawings]

FIG. 1 is a block diagram of an anti-theft device of the present invention.

FIG. 2 is a waveform diagram of an alarm device built in the antitheft device body of the same device.

FIG. 3 is a waveform diagram of an alarm sound according to another embodiment.

FIG. 4 is a configuration diagram of a conventional anti-theft device body.

FIG. 5 is a waveform diagram of a conventional alarm sound.

[Explanation of symbols]

 1 sounding device 2 battery 5 receiving circuit 6 tag code 7 transistor [separation detecting means] 12 oscillator 13 anti-theft device body 14 detecting device 15 alarm device 17 microphone 18 amplifier 19 first synchronous filter 20 second synchronous filter 23 AND Gate 25 Warning light S1 First signal S2 Second signal S3 Warning sound

Claims (1)

[Claims] 1. A transmitter for radiating a signal of a specific frequency is provided near the exit of the control area to amplify the detected sound and determine whether or not a signal of a predetermined specific frequency is included in the detected sound. The anti-theft device body that is attached to the product to be protected is equipped with a detection device that detects the presence of multiple types of signals of a predetermined specific frequency and switches the output circuit. Separation detection means for detecting removal from the product, and the separation detection means detects the separation of the anti-theft device body from the protection target product or the signal of a specific frequency, and is set. An anti-theft device provided with an alarm device that generates a multiple signal as an alarm sound.