JP2511459Y2 - Alarm device for shoplifting prevention device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alarm device attached to a product for preventing shoplifting.

[0002]

2. Description of the Related Art Conventionally, two types, a high frequency type and a low frequency type, have been widely used as shoplifting prevention devices. In a high frequency type shoplifting prevention device, a tag incorporating a circuit that resonates with a radio wave having a relatively high frequency is attached to a product in advance. The tag is removed from the item when the item is paid for. On the other hand, when shoplifting is performed, the resonance circuit of the tag attached to the product resonates with the weak electric wave emitted from the transmitting antenna installed at the exit to emit a minute electric wave. The reception antenna detects this radio wave and activates the alarm device.

This type of shoplifting prevention device does not require a power source for a tag attached to a product, and it is possible to manufacture a small and thin tag like a bar code sticker by using a printed wiring technique. But above the tag 10
There are drawbacks such that the tag does not work due to its shielding effect and the tag can be easily peeled off from the product simply by mounting the yen coin.

On the other hand, in a low frequency type anti-shoplifting device, a primary coil excited by a relatively low frequency is installed at the exit, and an alarm device equipped with a secondary coil for inducing a voltage by this primary coil Are attached in advance. When shoplifting is performed, a voltage is induced in the secondary coil of the alarm device at the exit, and an alarm sound is emitted from the alarm device.

FIG. 9 is a view for explaining an alarm device attached to a product in such a low frequency type shoplifting prevention device, A is a perspective view of the alarm device, and B is an example of an electrical configuration of the alarm device. It is a block diagram shown roughly.
In FIGS. A and B, the alarm device is in an operating state by connecting the internal power source and each circuit element by closing the power switch SW. When a shoplifter tries to leave an outlet with a product, the low-frequency detector 1 detects a low-frequency signal from a primary coil attached to the outlet and induces a voltage. This voltage is amplified by the output unit 2,
Drive the buzzer 3. Once a voltage sufficient to operate the buzzer 3 is output from the output unit 2, the holding circuit 4 holds the output from the output unit 2 and continues to ring the buzzer 3.

Further, a limit switch 5 is connected between the internal power supply and the buzzer 3. Limit switch 5
Is an arm 6 that is partly protruding outside the alarm device.
Is turned on and off by. That is, when the alarm device is attached to the product so that the arm 6 contacts the product, the limit switch 5 is kept off because the arm 6 is pushed into the alarm device, but the alarm device is peeled off from the product. If a gap greater than a predetermined value is created between the alarm device and the product, the arm 6 moves outward and turns on the limit switch 5, so that the internal power source is connected to the buzzer 3 and the buzzer 3 Will work.

FIG. 10 is a circuit diagram showing in detail the electrical configuration of the alarm device of FIG. In FIG. 10, the resistor R1
1, capacitor C11 and NPN transistor Tr11
Constitutes a holding circuit 4, a secondary coil CL, a capacitor C
The resistor 12, the resistor R12, and the NPN transistor Tr12 form the low-frequency detector 1. The secondary coil CL and the capacitor C12 form a low frequency detection resonance circuit that resonates at, for example, 22.9 KHz. The PNP transistor Tr13 and the electrolytic capacitor C13 form the output unit 2, and the limit switch 5 is connected between the collector and the emitter of the transistor Tr13. Buzzer 3 and limit switch 5
The connection point between and is connected to the base of the transistor Tr11 via the diode D and the resistor R13 to form the holding circuit 4. Reference numeral 7 is a lithium battery (for example, 3 volts) that is an internal power source.

Since this low frequency type anti-shoplifting device uses a frequency much lower than that of the high frequency type tag,
The alarm device is not easily affected by the shielding effect of metal, and as described above, the alarm sound is emitted when the alarm device is peeled off from the product, so that the effect of suppressing shoplifting is high. However, by inserting a thin plate between the alarm device and the product to prevent the arm 6 from projecting outward, the limit switch 5 can be made inoperable, so that the alarm device can be easily manufactured. It has the drawback of being removable from. Further, the power switch S of the alarm device is turned on / off from the outside by a key, but this key often has a simple mechanical structure, and a person who knows the structure operates the key with a wire or the like. Then, there is also a drawback that the power switch S can be easily turned off.

[0009]

The present invention has been made in order to solve the above-mentioned drawbacks, and it is difficult to obstruct the operation, and the shoplifting prevention device can surely operate at the time of shoplifting. It is an object of the present invention to provide an alarm device for use.

[0010]

In order to achieve the above object, the present invention is an alarm device for a shoplifting prevention device, which is attached to a product and has a built-in power source, which responds to a signal supplied from the outside. A circuit for turning the power on and off, a limit switch that operates when the alarm device for shoplifting prevention device is removed from the product, and an alarm generation unit that generates an alarm when the limit switch operates when the power is on. An alarm device for a shoplifting prevention device, comprising: a protective plate that is provided around the limit switch and that prevents illegal action against the limit switch. The above-mentioned signal supplied from the outside is, for example, a signal having a predetermined frequency, pulse code or current polarity. In one embodiment of the present invention, the limit switch is controlled by an arm so as not to operate when the arm is in contact with a product,
Also, a protection plate is provided to prevent an illegal act against the arm.

[0011]

The power source is turned on and off in response to a signal having a predetermined frequency, pulse code or current polarity from the outside, and the limit switch operates when the shoplifting prevention alarm device is removed from the product. If the limit switch is activated when is on, an alarm will be generated. The protective plate prevents illegal activities for deactivating the limit switch.

[0012]

1 is a block diagram schematically showing the electrical construction of an alarm device AL for a shoplifting prevention device according to the present invention, and FIGS. 2A and 2B are perspective views of the alarm device AL and FIG. It is a side view. In these figures, the same components as those shown in FIGS. 3 and 4 are designated by the same reference numerals, and the description thereof is omitted here.

In FIG. 1, an alarm device AL attached to a product has a high-frequency resonance portion 8 which resonates with a high-frequency wave (for example, a short wave) emitted from a transmitting antenna installed at an exit to emit a minute electric wave. It has a high frequency part which it has, and a low frequency part which induces a voltage and operates the buzzer 3 when a low frequency signal from the primary coil installed at the outlet is detected.

The high frequency resonance section 8 is similar to the conventional one.
A tag that resonates with high frequency radio waves and emits weak radio waves may be used. On the other hand, the low frequency section includes, in addition to the low frequency detection section 1, the output section 2, the buzzer 3, the holding circuit 4 and the limit switch 5,
A power on / off circuit 9 and a latching relay 10 which is turned on / off by the output of the power on / off circuit 9 and holds the state.
And a contact 10 'of the latching relay 10
Is connected to a position where the voltage from the internal power supply can be supplied to each component of the low frequency part.

When the alarm device AL is attached to the product, the power-on / off circuit 9 is supplied from an external circuit 11 separate from the alarm device AL.
To work. As a result, the latching relay 10 is turned on and its contact 10 'is closed to maintain the state, so that the alarm device AL keeps the operating state. The subsequent operation is shown in FIG.
And as already described with reference to FIG. It should be noted here that, as will be described later in detail, the power-on / off circuit 9 operates once and then reverses to a specific frequency or pulse code which is not used in another store or when it is turned on. This means that the alarm device can be turned off externally only by a specific person, because it can be turned off only by the current of the polarity.

Further, the alarm device according to the present invention has the configuration shown in FIG.
As shown in FIG. 3, protective plates 12 and 13 that are the same as or slightly longer than the arm 6 and obliquely protrude are provided on both sides of the arm 6. Since the protective plates 12 and 13 are deformed when the alarm device is attached to the product, they do not hinder the pushing of the arm 6. Moreover, even if a thin plate is inserted between the product and the alarm device for shoplifting and the arm 6 is kept pushed in, the thin plate cannot reach the arm 6 because of the protection plates 12 and 13, and the force is still forced. When the thin plate is pushed in, a gap larger than a predetermined amount is created between the product and the alarm device, the arm 6 moves outward, and the buzzer 3
To work.

Next, some specific examples of the external circuit 11 and the power-on / off circuit 9 which is turned on / off by the external circuit 11 will be described. FIG. 3 shows an example of an external circuit 11 that outputs a signal modulated at a specific frequency, and a power on / off circuit 9 that is turned on / off by the external circuit 11 to set / reset the latching relay 10. The external circuit 11 is provided with a switch SW1, and a direct current is applied from the output terminals O ₁ -O ₂ to the input terminals I ₁ -I ₂ of the power on / off circuit 9 when the switch SW1 is turned off, and the switch SW1 is turned on. When
A pulsating current in which a direct current is interrupted is given by an oscillation output of a predetermined frequency from the oscillation circuit OSC. The power on / off circuit 9 receives the direct current from the input terminals I ₁ -I ₂ and the latching relay 1
The set coil X _{1 of} 0 is turned on to close the contact 10 ′, and power is supplied to the alarm circuit AL. On the other hand, when a pulsating flow is applied to the input terminals I ₁ -I ₂ , the reset coil X ₂ of the latching relay 10 is turned on by the resonance operation of the resonance circuit RC including the coil L ₁ and the capacitor C _1, and the contact 10 'Is opened and the alarm circuit AL is turned off.

In the power-on / off circuit 9, the reset coil X ₂ is not turned on and the set coil X ₁ is turned on unless the frequency given from the outside matches the resonance frequency of the resonance circuit RC. Therefore, if the resonance frequency range of the resonance circuit RC is narrowed, the probability of turning on the reset coil X ₂ can be lowered even if the frequency given from the outside is changed, and even if the reset coil X _{2 is} reset.
Even if you can turn on, you cannot see it from the outside.

FIG. 4 shows an external circuit 11 for outputting a digital signal modulated with a specific pulse code, and FIG.
Is turned on and off by this digital signal to set and reset the latching relay 10
Is shown. The external circuit 11 is an encoder which outputs a 4-bit code which differs depending on the pressed key of the keyboard KB, and which has an output terminal 2 ⁰ -2 ³ to turn on / off the power circuit 9.
The 4-bit code is sent to the input terminals I ₁ , I ₂ , I ₄ , and I ₈ . For example, if you press the key C on the keyboard KB once, the corresponding 4-bit code is output once.
The bit code is identified by the power on / off circuit 9, and the set coil X ₁ of the latching relay 10 is turned on, and the contact 1
Power is supplied to the alarm circuit AL by closing 0 '. on the other hand,
When key C is continuously pressed a predetermined number of times, the number of times key C is pressed is detected, and reset coil X _{2 of} latching relay 10 is detected.
Is turned on to open the contact 10 'and the alarm circuit is turned off. Note that reference numerals IC1 to IC5 in FIG. 5 are integrated circuits used here, and the respective numbers are 14585, 14022, 14015, and 1408 in order from IC1.
2, 14093, specifically, IC1 is a comparison circuit between the input and the set value, IC2 is a sequential switcher, IC3 is a match number detection circuit of IC1, IC4 is an AND circuit, and IC5.
Is a waveform shaping NAND circuit. Reference numerals N1 to N4 are setting switches.

FIG. 6 shows an example in which an external circuit 11 that outputs currents of different polarities is directly connected to the latching relay 10. In this case, the power on / off circuit 9 is omitted. The latching relay 10 is a one-winding type, and when the switch SW2 of the external circuit 11 is set to the set side, the coil X of the latching relay 10 is energized to turn on the latching relay 10 and close the contact 10 '. On the other hand, when the switch SW2 is set to the reset side, the latching relay 10
Current flows in the opposite direction to the coil X of the latching relay 1
0 turns off and opens contact 10 '.

In the above description, the low frequency part of the alarm circuit AL is assumed to have the conventional circuit configuration shown in FIG. 10, but another circuit example of the low frequency part will be described here. Figure 7
Shows the first example thereof, and the capacitor C2 that constitutes the low-frequency detection resonance circuit together with the secondary coil CL is the capacitance of the secondary coil CL itself. The buzzer 3 is a piezoelectric type and has a built-in oscillator. In this circuit, when the alarm device is removed from the product, the limit switch 5 closes and turns on the transistor Tr7. As a result, the transistor Tr8 also turns on, causing the buzzer 3 to ring. At this time, the transistor Tr7 is kept on by the transistor 8 and the resistor R1 in the on state, so that the buzzer 3 continues to ring until the contact 10 'of the latching relay 10 is opened. On the other hand, even when the secondary coil CL and the capacitor C2 resonate at the frequency of the magnetic field formed by the primary coil at the exit, the transistors Tr7 and T7
Since r8 is turned on and holds that state, contact 1
Buzzer 3 continues to ring until 0'is opened.

Since the circuit of FIG. 7 has only one secondary coil, the sensitivity of the alarm device AL depends on the direction of the magnetic field formed by the primary coil installed at the outlet and the secondary coil of the alarm device AL. It will be different. In order to eliminate this, a plurality of secondary coils having sensitivity in different directions may be provided. FIG. 8 shows a circuit configuration in which three secondary coils CL _X , CL _Y and CL _Z are arranged in three orthogonal directions to form a resonance circuit with capacitors C _X , C _Y and C _Z , respectively. Shows. The output of each resonance circuit is amplified by the transistors Tr _X , Tr _Y and Tr _Z. Note that these resonance circuits may be connected in parallel and amplified by one transistor.

As described above, in this alarm device,
Once activated, the alarm device will only be used by special people by sending a specific frequency or pulse code that is not used in other stores, or a current of the opposite polarity to that used when turning it on. Since it is not possible to externally turn off the power of the device, shoplifting by turning off the internal power to disable the alarm device can be prevented. In addition, shoplifting by placing the limit switch in an inoperable state becomes impossible. Furthermore, since it has both a high-frequency part and a low-frequency part, it is difficult to disable both of them at the same time. Even if the internal power supply of the frequency section can be turned off, the high frequency section operates, so that the occurrence of shoplifting can be detected with high accuracy.

[0024]

As is apparent from the above description of the present invention in detail with reference to some embodiments, the alarm device according to the present invention can be operated only by a special person once it is activated. Since it is not possible to turn off the power of the alarm device from the outside, it is possible not only to prevent shoplifting by turning off the internal power to disable the alarm device, but also to disable the limit switch. Since shoplifting by placing it is also impossible, shoplifting can be reliably prevented. In addition, since it has both a high frequency section and a low frequency section, it is difficult to disable both of them at the same time. Even if the internal power supply of the frequency section can be turned off, the high frequency section operates, so that it is possible to obtain a special effect that the occurrence of shoplifting can be detected with high accuracy.

[Brief description of drawings]

FIG. 1 is an alarm device AL for a shoplifting prevention device according to the present invention.
3 is a block diagram schematically showing the electrical configuration of FIG.

2A is a perspective view of the alarm device AL of FIG. 1, and B is a side view thereof.

FIG. 3 is a diagram showing a first example of a specific circuit of the power on / off circuit 9 in the alarm device AL according to the present invention, which is turned on / off by an external circuit 11 which outputs a signal modulated at a specific frequency. It is a figure which shows the power supply ON / OFF circuit 9 which is set and resets the latching relay 10 which is carried out.

FIG. 4 is a diagram showing an external circuit 11 that outputs a digital signal modulated by a specific pulse code.

FIG. 5 is a diagram showing a second example of the power on / off circuit 9 of the alarm device AL according to the present invention, which is turned on / off by a digital signal from the external circuit 11 of FIG. 4 to set / reset the latching relay 10. Is.

FIG. 6 is a diagram showing a latching relay 10 of an alarm device AL according to the present invention, which is turned on and off by an external circuit 11 that outputs currents having different polarities.

FIG. 7 is a diagram showing an example of a circuit configuration of a low frequency section in the alarm device AL according to the present invention.

FIG. 8 is a diagram showing another example of the circuit configuration of the low frequency section in the alarm device AL according to the present invention.

FIG. 9 is a perspective view of a conventional alarm device, and B is a block diagram schematically showing its electrical configuration.

10 is a circuit diagram showing in detail the electrical configuration of the alarm device of FIG.

[Explanation of symbols]

1: Low frequency detection unit, 2: Output unit, 3: Buzzer, 4: Holding circuit, 5: Limit switch, 6: Arm, 7: Power switch, 8: High frequency resonance unit, 9: Power on / off circuit, 10:
Relay, 11/12: Protective plate

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Creator Toshio Goto 639, Sanwa-cho, Hamamatsu City, Shizuoka Prefecture (56) References JP-A-62-130492 (JP, A)

Claims (2)

(57) [Scope of utility model registration request] 1. An alarm device for shoplifting prevention device, which is attached to a product and has a built-in power supply, comprising: a circuit for turning on / off the power supply according to a signal supplied from the outside; and an alarm device for shoplifting prevention device. A limit switch that operates when the power switch is turned on, an alarm generation unit that generates an alarm when the limit switch operates when the power supply is on, and an illegal action against the limit switch that is provided around the limit switch. An alarm device for shoplifting prevention device, comprising: a protective plate for preventing the shoplifting. 2. The alarm device for a shoplifting prevention device according to claim 1, wherein the limit switch is controlled by an arm so as not to operate when the arm is in contact with a product, and the protection plate is the arm. An alarm device for shoplifting prevention devices, which is characterized by preventing illegal activities against.