JPH0665992U - Alarm device for shoplifting prevention device - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an alarm device capable of reliably preventing shoplifting. An alarm device for a shoplifting prevention device having a built-in power supply, the circuits 9 and 10 turning on and off the power supply in response to signals such as a predetermined frequency, pulse code, and polarity of current from the outside. First means 1, 2, 3, 4 for issuing an alarm in response to the occurrence of shoplifting when the power is on;
Second means 8 for notifying the occurrence of shoplifting regardless of whether the power is on or off. Further, a limit switch 5 that is closed when the alarm device is detached from the product to generate an alarm from the first means, and a limit switch 5
Protective plates 11 and 12 are provided around the edge of the limit switch 5 for preventing illegal action for making the limit switch 5 inoperative.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an alarm device attached to a product to prevent shoplifting.

[0002]

[Prior 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 anti-shoplifting device, a tag incorporating a circuit that resonates with a radio wave having a relatively high frequency is attached to a product in advance. When the product is paid for, the tag is removed from the product. 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 and emits a minute electric wave. This radio wave is detected by the receiving antenna and the alarm device is activated.

This type of shoplifting prevention device does not require a power source for the tag attached to the product, and it is possible to manufacture a small and thin tag like a barcode sticker by using the printed wiring technology. . However, there are some drawbacks such as simply putting a 10-yen coin on the tag makes it inoperable due to its shielding effect and making it easy to remove the tag from the product.

On the other hand, in a low-frequency shoplifting prevention 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 diagram for explaining a warning device attached to a product in such a low frequency type shoplifting prevention device, A is a perspective view of the warning device, and B is an example of an electrical configuration of the warning device. 2 is a block diagram schematically showing FIG. 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 and drives the buzzer 3. Once the output section 2 outputs a sufficient voltage to operate the buzzer 3, the holding circuit 4 holds the output from the output section 2 and keeps the buzzer 3 ringing.

Further, a limit switch 5 is connected between the internal power supply and the buzzer 3. The limit switch 5 is turned on and off by an arm 6 which is partly protruding outside the alarm device. 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. When the alarm device and the product are separated from each other and a gap greater than a predetermined value is created, the arm 6 moves outward and the limit switch 5 is turned on. The buzzer 3 is connected and the buzzer 3 operates.

FIG. 10 is a circuit diagram showing in detail the electrical configuration of the alarm device of FIG. In FIG. 10, the resistor R11, the capacitor C11 and the NPN transistor Tr11 constitute the holding circuit 4, and the secondary coil CL, the capacitor C12, the resistor R12 and the NPN transistor Tr12 constitute the low frequency detection unit 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. The connection point between the buzzer 3 and the limit switch 5 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 due to the metal, and as described above. However, when the alarm device is peeled off from the product, an alarm sound is emitted, which is highly effective in suppressing shoplifting. 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 operated. It has the drawback that it can be removed from the product. Also, the power switch S of the alarm device is turned on and 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 1 can be easily turned off.

[0009]

[Problems to be solved by the device]

 The present invention has been made to solve the above drawbacks, and it is an object of the present invention to provide an alarm device for a shoplifting prevention device, which is difficult to interfere with the operation and can be reliably operated during shoplifting. To aim.

[0010]

[Means for Solving the Problems]

 In order to achieve the above object, an alarm device for a shoplifting prevention device according to the present invention is a circuit for turning on / off an internal power supply in response to an external signal such as a predetermined frequency, pulse code, or polarity of current. Is equipped with. Further, a first means for issuing an alarm in response to the occurrence of shoplifting when the internal power source is on, and a second means for notifying the occurrence of shoplifting irrespective of whether the internal power source is on or off, A limit switch that is closed when the alarm device is removed from the product to generate an alarm from the first means, and is provided around the limit switch to prevent illegal activities for making the limit switch inoperative. And a protective plate for protection.

[0011]

[Action]

 The internal power supply is turned on and off in response to external signals such as predetermined frequency, pulse code, and current polarity. The first means issues an alarm in response to the occurrence of shoplifting when the internal power supply is on. The second means notifies the occurrence of shoplifting regardless of whether the internal power supply is on or off. The limit switch is closed when the alarm device is removed from the product to generate an alarm from the first means. A protective plate is provided around the limit switch to prevent illegal activities that render the limit switch inoperative.

[0012]

【Example】

 FIG. 1 is a block diagram schematically showing the electrical configuration of an alarm device AL for a shoplifting prevention device according to the present invention, and FIGS. 2A and 2B are a perspective view and a side view of the alarm device AL, respectively. . 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 will be omitted.

In FIG. 1, an alarm device AL attached to a product includes a high-frequency resonator 8 that resonates with a high-frequency wave (for example, a short wave) emitted from a transmitting antenna installed at an exit to emit a minute radio wave. It has a high-frequency part that it has, and a low-frequency part that 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 resonator 8 may be a tag that resonates with a high-frequency radio wave and emits a weak radio wave, as in a conventional one. On the other hand, the low frequency section is turned on and off by the power on / off circuit 9 and the output of this power on / off circuit 9 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. The latching relay 10 for holding the state is provided, and the 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 section.

When the alarm device AL is attached to a product, the power on / off circuit 9 is operated from an external circuit 11 separate from the alarm device AL. As a result, the latching relay 10 is turned on and its contact 10 'is closed to maintain its state, so that the alarm device AL maintains the operating state. Subsequent operations are as already described with reference to FIGS. 9 and 10. It should be noted here that, as will be described in detail later, the power-on / off circuit 9 operates once and then operates at a specific frequency or pulse code that is not used in another store or when it is turned on. This means that the alarm device can only be turned off by an external person, because it can only be turned off by a current of opposite polarity.

Further, in the alarm device according to the present invention, as shown in FIG. 2, protective plates 12 and 13 that are the same as or slightly longer than the arm 6 and project obliquely 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 pushed in, the thin plate cannot reach the arm 6 because of the protection plates 12 and 13. When the thin plate is pushed in by force, 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 operates.

Next, an example of a specific circuit including the external circuit 11 and the power on / off circuit 9 that 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 sets and resets the latching relay 10 that is turned on and off by the external circuit 11. The external circuit 11 is provided with a switch SW1, and DC is given 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. At this time, 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. When a direct current is applied to the input terminals I ₁ -I ₂ , the power on / off circuit 9 turns on the set coil X ₁ of the latching relay 10 to close the contact 10 ′, and power is supplied to the alarm circuit AL. It On the other hand, when the pulsating current 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 contacts 10 'is opened and the alarm circuit AL is turned off.

[0018] In this power supply on-off circuit 9 should match the resonant frequency of the frequency given resonant circuit RC from the outside, the reset coil X ₂ will not turn on, Settokoi Le X ₁ is turned on. 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 turned on. Even if something happens, it cannot be confirmed externally.

FIG. 4 shows an external circuit 11 for outputting a digital signal modulated by a specific pulse code, and FIG. 5 shows a power on / off for setting and resetting the latching relay 10 which is turned on / off by this digital signal. A circuit 9 is shown. The external circuit 11 is an encoder that outputs different 4-bit codes depending on the pressed key of the keyboard KB, and outputs from the output terminal 2 ⁰ -2 ³ to the input terminals I ₁ , I ₂ , I _{4 of the} power on / off circuit 9. , Send a 4-bit code to I ₈ . For example, when the key C on the keyboard KB is pressed once, the corresponding 4-bit code is output once, and the 4-bit code is identified by the power on / off circuit 9 and the set coil X _{1 of the} latching relay 10 is identified. Is turned on, the contact 10 'is closed, and power is supplied to the alarm circuit AL. On the other hand, when the key C is continuously pressed a predetermined number of times, the number of times the key C is pressed is detected, the reset coil X ₂ of the latching relay 10 is turned on, the contact 10 'is opened, and the alarm circuit is turned off. Note that reference numerals IC1 to IC5 in FIG. 5 are integrated circuits used here, and their numbers are 14585, 14022, 14015, 1408 2, and 14093 in order from IC1, and specifically, IC1 is a comparison circuit between the input and the set value, IC2 is a sequential switcher, IC3 is a matching 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 with different polarities is directly connected to the latching relay 10, and 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, a current flows in the opposite direction to the coil X of the latching relay 10, the latching relay 10 is turned off and the contact 10 'is opened.

In the above description, the low frequency part of the alarm circuit AL has been assumed to have the conventional circuit configuration shown in FIG. 10, but another circuit example of the low frequency part will be described here. FIG. 7 shows the first example, and the capacitor C2 that constitutes the low frequency detection resonance circuit together with the secondary coil CL is the electrostatic capacity 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 outlet, the transistors Tr7 and Tr8 are turned on and the state is maintained, so that the contact 10 'is opened. Buzzer 3 continues to ring until it is heard.

Since the circuit of FIG. 7 has only one secondary coil, the direction of the magnetic field formed by the primary coil installed at the outlet and the direction of the secondary coil of the alarm device AL causes the alarm device AL to move. The sensitivity will be different. In order to solve 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 resonant circuits may be connected in parallel and amplified by one transistor.

As described above, in this alarm device, once it is in the operating state, it has a specific frequency or pulse code that is not used in other stores, or a current with a polarity opposite to that when it is turned on. Since only a special person can turn off the power of the alarm device from the outside by sending etc., prevent shoplifting by turning off the internal power supply and disabling the alarm device. You can 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]

[Effect of device]

 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 by a special person only after it is activated. Since it cannot be turned off from the outside, it not only prevents shoplifting by turning off the internal power supply and disabling the alarm device, but also by putting the limit switch in an inoperable state. Since shoplifting will not be possible, shoplifting can be reliably prevented. In addition, 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 special effect of being able to detect the occurrence of shoplifting with high accuracy can be achieved.

[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) Inventor Noboru Tsuchiya 2-34-15 Kamoe, Hamamatsu City, Shizuoka Prefecture (72) Inventor Toshio Goto 639, Sanwa Town, Hamamatsu City, Shizuoka Prefecture

Claims (3)

[Scope of utility model registration request] 1. An alarm device for a shoplifting prevention device having a built-in power supply, comprising a predetermined frequency, pulse code from the outside,
An alarm device comprising a circuit for turning on / off the power source in response to a signal such as a polarity of current. 2. The alarm device according to claim 1, wherein when the power is on, first means for issuing an alarm in response to the occurrence of shoplifting and shoplifting regardless of whether the power is on or off. A second means for notifying the occurrence of 3. The alarm device according to claim 1, further comprising: a limit switch that is closed when the alarm device is detached from a product to generate an alarm from the first means; and a limit switch around the limit switch. An alarm device provided with a protective plate for preventing illegal action for making the limit switch inoperative.