JPH0521191Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a security device that is attached to a desired object and used at a predetermined location.

(Prior art) In recent years, for example, record stores, bookstores, etc.
Security devices are becoming widely used for the purpose of preventing products in stores from being stolen by unscrupulous individuals. In other words, this security device is equipped with a receiving circuit that receives a specific frequency signal.For example, the security device is installed in advance on products such as records in the store, and the above-mentioned frequency signal is transmitted near the entrance and exit of the store. If a customer attempts to illegally take away a record, etc. with a security device attached to it (without paying for it), when the customer attempts to exit through the store's entrance, A receiving circuit within the security device receives a frequency signal from a transmitting circuit, thereby emitting an alarm such as a buzzer.

FIG. 2 is a block diagram showing an example of this type of security device. As shown in FIG. 2, a power source 1,
The output from this power supply 1 is used as a driving source, and the antenna 2
A receiving circuit 3 that operates when receiving the frequency signal of F1 via the power source 1 and the output from the power source 1 are used as driving sources,
A receiving circuit 4 that operates when receiving a frequency signal F2 different from the frequency signal F1, and each receiving circuit 3, 4.
AND circuit 5 that obtains the AND output of the operation outputs from
and a buzzer drive circuit 7 which operates to sound the buzzer 6 when the logical product output from the AND circuit 5 is input.

In other words, if the security device shown in Figure 2 is attached to a record or other product in the store, and a customer attempts to take it away illegally with the security device attached to the record, etc., the customer will be unable to exit through the store's entrance. When this happens, the receiving circuits 3 and 4 respectively receive the F1 and F2 frequency signals transmitted from the transmitting circuit installed near the entrance of the store, and the AND circuit 5 establishes the logical product condition. The output is input to a buzzer drive circuit 7, and the buzzer 6 issues an alarm.

(Problems to be Solved by the Invention) However, the conventional crime prevention device as described above has the following problems. That is, since each of the receiving circuits 3 and 4 and the buzzer drive circuit 7 are constantly in operation due to the output from the power supply 1, the power consumption by these circuits is large (particularly the power consumption by the receiving circuits 3 and 4 is large). The security device cannot be used for a long period of time. Furthermore, if the AND circuit 5 becomes defective for some reason, its output will be input to the buzzer drive circuit 7 and the buzzer 6 will erroneously issue an alarm.

This invention was developed to solve the above-mentioned problems, and its purpose is to reduce power consumption so that the device can be used for a long time, and to prevent malfunctions due to defective parts. Our goal is to provide a highly reliable security device without any problems.

(Means for solving the problem) In order to achieve the above object, the security device of the present invention uses a power source and the output from the power source as a driving source,
A first receiving circuit that operates upon receiving a first frequency signal, and an output from a power source as input, operates on the condition that an operational output is input from the first receiving circuit, and transmits the power output. a power supply controller, a second reception circuit that uses the output from the power supply controller as a drive source and operates when receiving a second frequency signal different from the first frequency signal; and a second reception circuit that uses the output from the power supply controller as a drive source. The driving source is a latch circuit that latches the AND output of the operation outputs from the first and second receiving circuits, and the output from the power supply controller, and the condition is that the latch output from the latch circuit is input. The alarm circuit is configured to include an alarm circuit that operates and sends out an alarm output.

(Function) Therefore, in the security device of the present invention, the first receiving circuit is always in operation due to the output from the power source. On the other hand, in this state, the first receiving circuit
By receiving and operating the frequency signal, an output from the power supply is sent through the power supply controller, and the second receiving circuit, the latch circuit, and the alarm circuit are activated. In this state, when the second receiving circuit receives the second frequency signal and operates, the AND output of the operation outputs of the first and second receiving circuits is latched by the latch circuit. The latch output will be input to the alarm circuit and an alarm output will be sent out.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the security device according to the present invention.

That is, as shown in FIG.
a first receiving circuit 10 that operates upon receiving 1;
The output from the power supply 8 is input, and the first receiving circuit 1
The first latch circuit 11 that latches the operation output from 0 and the output from the power supply 8 are input, and on the condition that the latch output is input from the first latch circuit 11, the timer time T operates and the operation output is performed. a timer circuit 12 that sends out the power output, a power supply controller 13 that operates on the condition that the operation output from the timer circuit 12 is input, and sends out the power output; The second receiving circuit 14 operates when it receives a second frequency signal F2 different from the first frequency signal F1, and the AND output of the operating output from the timer circuit 12 and the operating output from the receiving circuit 14 is calculated. Obtain AND circuit 15
and a second circuit which uses the output from the power supply controller 13 as a driving source and latches the AND output from the AND circuit 15.
The latch circuit 16 and the output from the power supply controller 13 are used as driving sources, and the buzzer 1 operates on the condition that the latch output is input from the second latch circuit 16.
7 and a buzzer drive circuit 18 that makes the buzzer 7 sound. Here, the buzzer 17 and the buzzer drive circuit 18 constitute an alarm circuit.

Next, the operation of the security device configured as described above will be described.

The first receiving circuit 10, the first latch circuit 11, and the timer circuit 12 are constantly activated by the output from the power source 8. On the other hand, when the first receiving circuit 10 receives the first frequency signal F1 and operates in such a state, its operating output is latched by the first latch circuit 11, and is further latched by the latch output from now on. The timer circuit 12 operates for a timer time period T and outputs an operational output. Then, the power supply controller 13 is operated by the operation output from the timer circuit 12, and the output from the power supply 8 is sent out. As a result, the second receiving circuit 14,
The second latch circuit 16 and buzzer circuit 18 are activated. In this state, the second receiving circuit 14 receives the second frequency signal F2 and operates, so that the AND condition of the operational output of the timer circuit 12 and the operational output of the second receiving circuit 14 is established as an AND circuit. 15, and this output is latched by the second latch circuit 16. Finally, this latch output is input to the buzzer drive circuit 18, and the buzzer 17 remains until the timer circuit 12 resumes operation.
An alarm will be issued.

Therefore, for example, if the security device of this embodiment is attached to a product such as a record in a store, and a customer attempts to take it away illegally with the security device still attached to the record, etc., the customer will be able to enter the store through the entrance. When attempting to leave the store, the first and second receiving circuits 10 and 14 receive the F1 and F2 frequency signals transmitted from the transmitting circuit installed near the entrance of the store. When the AND condition is satisfied, the latch is latched by the second latch circuit 16, the latch output is input to the buzzer drive circuit 18, and the buzzer 17 issues an alarm.

As described above, in the security device of this embodiment, the first receiving circuit 10 and the first latch circuit 11 are always connected.
Only the timer circuit 12 is kept in operation, and the first receiving circuit 10 receives the first frequency signal F1.
The power supply controller 13
Since the remaining second receiving circuit 14, second latch circuit 16, and buzzer circuit 18 are activated through The power consumption of the latch circuit 16 and the buzzer circuit 18 can be reduced, and the security device can be used for a longer period of time than conventional devices. Furthermore, even if the AND circuit 15 becomes defective for some reason, the second latch circuit 1
6 does not work, so the buzzer 1 may be activated due to defective parts.
7 will no longer be erroneously issued. Furthermore, the operation output of the timer circuit 12 and the second
The second latch circuit 16 latches the output of the AND circuit 15 which inputs the operational output of the receiving circuit 14, so that the second frequency signal F2 cannot be obtained continuously due to radio wave interference or the like. Even in such a case, it is possible to reliably generate an alarm using the buzzer 17.

In the above embodiment, the operational output of the first receiving circuit 10 is provided to the power supply controller 13 via the first latch circuit 11 and the timer circuit 12, but the first latch circuit 11 and the timer circuit 12 may be omitted and the operational output of the first receiving circuit 10 may be directly provided to the power supply controller 13.

(Effects of the invention) As explained above, according to the invention, the device can be used for a long time with low power consumption, and it is extremely reliable and does not malfunction due to defective parts. We can provide high security devices.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the security device according to the present invention, and FIG. 2 is a block diagram showing a conventional security device. 8...Power supply, 9...Antenna, 10...First receiving circuit, 11...First latch circuit, 12...
Timer circuit, 13...Power controller, 14...Second receiving circuit, 15...AND circuit, 16...Second latch circuit, 17...Buzzer, 18...Buzzer drive circuit.

Claims (1)

[Scope of utility model registration request] a power source; a first receiving circuit that uses an output from the power source as a driving source and operates when a first frequency signal is received; an output from the power source is an input; and an operating output from the first receiving circuit is input. a power supply controller that operates and sends out the power output under the condition that the power supply output is received; and a power supply controller that uses the output from the power supply controller as a drive source and operates when a second frequency signal different from the first frequency signal is received. a second receiving circuit; a latch circuit that uses the output from the power supply controller as a driving source and latches the AND output of the operational outputs from the first and second receiving circuits; 1. A crime prevention device comprising: an alarm circuit that uses an output as a driving source and operates to send out an alarm output on condition that a latch output is input from the latch circuit.