JP2002288747A - Sensor for theft prevention device and theft prevention device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor for a theft prevention device preventing the realization of a condition in which an alarm is not outputted even if a member like a thin plate and having strength is inserted into a bonding part of a pressure sensitive adhesive double coated tape. SOLUTION: This sensor 11 for the theft prevention device is bonded to an object 13 for preventing theft to detect its bonding condition and removal condition by conductivity/non-conductivity of an electric circuit. This sensor 11 is provided with a projecting part 16 to be inserted into a screw hole 14 for mounting a support leg provided in the object 13 for preventing theft and detection means 17, 10 provided in the projecting part 16 and detecting a condition in which the projecting part 16 is inserted into the screw hole 14 and a condition in which it is pulled out of the screw hole 14. The bonding condition and the removal condition are detected by detecting the projecting part 16 inserted condition and the projecting part 16 pulled out condition by the detection means 17, 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sensor for an anti-theft device which is attached to an anti-theft object and detects the attached state and the detached state by the conduction / non-conduction of an electric circuit.
And an improvement of an anti-theft device provided with the anti-theft sensor.

[0002]

2. Description of the Related Art Some conventional anti-theft sensors include an automatic reset type push button switch. This anti-theft sensor is designed to prevent theft so that the push button switch is pressed. It is attached to the object with double-sided tape, and the attached state and the detached state are detected based on the pressed state and the return state of the push button switch. When the anti-theft sensor is removed from the anti-theft object, the state of the push button switch is detected by the return of the push button switch, and the anti-theft device equipped with the sensor outputs an alarm. Also, when the cord connecting the anti-theft device sensor and the anti-theft device body (the anti-theft tag) is disconnected, the anti-theft device is in the same state as when the push button switch is returned, and the alarm is also issued. Is output.

[0003] On the other hand, even if the anti-theft device is removed from the counter without removing the anti-theft sensor so that an alarm is not output, the anti-theft main unit is not provided with a signal provided near the exit of the counter. It receives a predetermined signal from the device and outputs an alarm. As described above, the anti-theft device is
If the anti-theft sensor is set with the anti-theft sensor attached to the anti-theft object, the anti-theft device sensor will be removed from the anti-theft object unless the anti-theft sensor is reset by a predetermined procedure. An alarm is output even when an object is attempted to be taken out of the exit of the counter, so that the theft of the product can be prevented.

[0004]

In the conventional anti-theft device sensor and anti-theft device described above, the anti-theft device sensor is attached to the anti-theft object with double-sided tape so that the push button switch is pressed. Since it is affixed, insert a strong thin plate-like member into the adhesive part of the double-sided tape, sandwich the inserted member between the push button and the anti-theft object, and press the push button switch Then, there is a problem that the alarm is not output even if the sensor for the anti-theft device is removed. Even if the tip of the push button is provided with an incline and the member is devised so as not to be caught between the push button and the anti-theft object, if the push button is pushed with a strong force, the result is the same with the strength of the push button. is there.

[0005] Even if the anti-theft device sensor and the anti-theft device main body are short-circuited in the middle of the cord connecting the anti-theft device main body, the anti-theft device main body is in the same state as the state where the push button switch is pressed. If the cord is cut off from the portion near the anti-theft device sensor, there is a problem that the anti-theft device body can be removed from the anti-theft object without outputting an alarm.

The present invention has been made in view of the above circumstances, and in the first to third inventions, even if a strong thin plate-shaped member is inserted into the adhesive portion of the double-sided tape, an alarm is issued. An object of the present invention is to provide a sensor for an anti-theft device that cannot be set to a state in which output is not performed. A fourth object of the present invention is to provide a sensor for an anti-theft device that can detect a short circuit even if a short circuit occurs in a cord connecting the anti-theft device body and the anti-theft device sensor. Fifth
An object of the invention is to provide an anti-theft device including the anti-theft sensor according to the first to fourth inventions. Sixth
An object of the present invention is to provide an anti-theft device further including a transmitter for transmitting a predetermined signal to be received by a receiving unit.

[0007]

A sensor for an anti-theft device according to the first invention is attached to an anti-theft object, and detects the attached state and the detached state by conducting / non-conducting an electric circuit. A projection to be inserted into a screw hole for mounting a support leg provided in the antitheft object, a state provided in the projection, the state in which the projection is inserted into the screw hole, and the screw hole Detecting means for detecting a state of being removed from the apparatus, and the detecting means detects the inserted state and the removed state to detect the attached state and the removed state. I do.

[0008] In this sensor for an anti-theft device, the anti-theft sensor is attached to an object to be anti-theft, and the attached state and the detached state are determined as follows.
It is detected by the conduction / non-conduction of the electric circuit. A projection is provided for insertion into a screw hole for mounting the support leg provided on the anti-theft object, and the detecting means provided on the projection is removed from the screw hole with the projection inserted into the screw hole. Detected state. The detecting means detects the attached state and the removed state by detecting the inserted state and the removed state. This makes it possible to realize a sensor for an anti-theft device in which even if a strong thin plate-shaped member is inserted into the adhesive portion of the double-sided tape, an alarm cannot be output.

A sensor for an anti-theft device according to a second invention is
The sensor further includes a bottomed tubular member that is screwed into the screw hole and into which the protrusion is to be inserted, and wherein the detection unit is configured to contact and separate a distal end of the protrusion and a bottom of the tubular member. By detecting, the inserted state and the removed state are detected.

The anti-theft sensor further includes a bottomed tubular member screwed into the screw hole and into which the protrusion is to be inserted, and the detecting means includes a tip of the protrusion and a bottom of the tubular member. By detecting the contact and separation of the protruding part, the inserted state and the removed state are detected, so even if a strong thin plate-shaped member is inserted into the adhesive part of the double-sided tape, an alarm is output It is possible to realize a sensor for an anti-theft device that cannot be turned off.

[0011] A sensor for an anti-theft device according to a third aspect of the present invention comprises:
The bottom of the tubular member has conductivity, the tip of the protrusion has two electrodes to be conducted by the bottom, and the detecting means is configured to conduct and disconnect between the two electrodes. , The contact and the separation are detected.

In this sensor for an anti-theft device, the bottom of the tubular member has conductivity, and the tip of the projection has two electrodes that are electrically connected to the bottom of the tubular member. Since the contact and separation between the tip of the protrusion and the bottom of the tubular member are detected by conduction and non-conduction between the two electrodes,
Even if a strong thin plate-shaped member is inserted into the adhesive portion of the double-sided tape, it is possible to realize a sensor for an anti-theft device in which an alarm cannot be output.

[0013] A sensor for an anti-theft device according to a fourth aspect of the present invention comprises:
A resistor inserted in the electric circuit, and further provided with means for detecting the presence or absence of a voltage across the resistor provided outside the resistor, and the means for detecting absence of the voltage across the resistor,
It is characterized by detecting a short circuit of the electric circuit outside the circuit.

In this anti-theft sensor, the resistor is inserted in the electric circuit, and the detecting means provided outside detects the presence or absence of the voltage at both ends of the resistor, and the detecting means detects the voltage at both ends. The short circuit of the electric circuit outside is detected by detecting the absence of the anti-theft device. Therefore, even if a short circuit occurs in the middle of the cord connecting the anti-theft device main body and the anti-theft device sensor, the short circuit should be detected. Can be realized.

[0015] The anti-theft device according to the fifth invention is characterized in claim 1.
A sensor for receiving an anti-theft device described in any one of claims 1 to 4, a receiving means for receiving a predetermined signal in a non-contact manner, and when the sensor for the anti-theft device detects a detached state, the sensor for the anti-theft device is electrically operated. Means for outputting an alarm when a short circuit is detected and when the receiving means receives a predetermined signal.

The anti-theft device comprises the anti-theft sensor according to any one of claims 1 to 4, wherein the receiving means receives a predetermined signal in a non-contact manner and outputs an alarm, When the sensor for the device detects the removal state, when the sensor for the anti-theft device detects the short circuit of the electric circuit, and when the receiving means receives the predetermined signal, an alarm is output. An anti-theft device equipped with such a sensor for an anti-theft device can be realized.

The anti-theft device according to a sixth aspect of the present invention is characterized by further comprising a transmitter for transmitting a predetermined signal to be received by the receiving means. The anti-theft device further includes a transmitter for transmitting a predetermined signal to be received by the receiving means. Therefore, when the product to which the anti-theft device is attached is taken out of the sales floor, an alarm is output to output an alarm. The device can be realized.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings showing an embodiment. FIG. 1 is an external view and a partial cross-sectional view for explaining a sensor for an anti-theft device and an anti-theft tag (the anti-theft device main body) according to the present invention. The anti-theft sensor 11 is a screw hole member 1 for a tripod of a product 13 (theft prevention object) with a screw hole for a tripod (support leg) such as a camera, a digital camera, and a video camera.
9, a bottomed tubular member 15 screwed into a screw hole 14 provided in the cylindrical member 9, and a protrusion 16 inserted into the tubular member 15.
The surface on the same side as the protrusion 16 is adhered to the surface of the product 13 where the screw hole 14 is provided by the double-sided tape 18.

The anti-theft sensor 11 also has
It has a sensor cord adapter 10 connected by a curl cord 12 and connected between an anti-theft device sensor 11 and an anti-theft tag 9. Sensor cord adapter 10
Is formed in the same shape as the anti-theft tag 9,
Adhered to. At the tip of the protrusion 16 of the anti-theft device sensor 11, two electrodes 17 connected to the sensor code adapter 10 by the curl cord 12 are provided. The anti-theft device sensor 11 has one of the electrodes 17 and A resistor R11 connected between the curl cords 12 is built in.

FIG. 2 is a perspective view showing the appearance of the sensor 11 for the anti-theft device. The anti-theft device sensor 11 has a thin plate shape, for example, a thickness of 3 mm, a length and width of 20 mm × 3
It has a size of about 0 mm, and is provided with a protrusion 16 on one surface, and a portion of the other surface excluding the protrusion 16 is adhered to the product 13 with a double-sided tape 18. The protruding portion 16 is made of resin similarly to other portions of the anti-theft device sensor 11, and has two electrodes 17 at its tip.

FIG. 3 is a perspective view showing the external appearance of the tubular member 15. The outer surface of the tubular member 15 is threaded, and the end on the mouth side is threaded. I have. FIG.
It is the top view (a) which shows the external dimension of the cylindrical member 15, the longitudinal cross section (b), and the side view (c). Screw hole 14 for tripod
Is JIS standard, screw nominal 1 / 4-20UNC
The pitch is 1.270 mm and the valley diameter is 6.
An internal thread having a diameter of 350 mm and an inner diameter of 4.976 mm is cut on the inner surface. Therefore, the outer surface of the cylindrical member 15 is also provided with the 1 / 4-20 UNC external thread.

The diameter of the tripod screw hole 14 is determined as described above, but the depth depends on the product 13.
It varies from 4 mm to 7.6 mm. Therefore, if the depth is set to, for example, 3.5 mm and a cylindrical member 15 whose inner bottom is gold-plated is prepared, the two electrodes 17 are connected to the cylindrical member 1.
The length of the protruding portion 16 for abutting on the bottom of the fifth device 5 is determined, and the anti-theft sensor 11 that can be used for any product having the tripod screw hole 14 can be realized. A flange having a diameter of 6.8 mm is provided at the end on the mouth side of the cylindrical member 15 so as to fit into a concave portion provided around the mouth of the screw hole 14 for a tripod.

In this embodiment, the state in which the anti-theft device sensor 11 is removed from the product 13 is detected by checking whether or not the two electrodes 17 contact the gold-plated bottom of the tubular member 15. However, for example, by providing an automatic return type push button switch at the tip of the projection 16 or by providing an automatic return type push button switch on the side surface of the projection 16, It is possible to detect the inserted state and the removed state. Further, even when the tubular member 15 is not provided, it is possible to detect a state in which the protrusion 16 is inserted into and removed from the screw hole 14.

FIG. 5 is a block diagram showing a configuration example of the anti-theft device sensor 11 and the sensor cord adapter 10. As shown in FIG. The sensor 11 for the anti-theft device includes two electrodes 17 indicated by an automatic return a contact, and a resistor R11 connected between one of the electrodes 17 and one of the curl cords 12.
The other of the electrodes 17 is the curl cord 12
Connected to the other cord. One of the curl codes 12 is connected to one terminal of a resistor R12 in the sensor code adapter 10 and to each of the inverting input terminals of the comparison circuits CM1 and CM2, and the other terminal of the resistor R12 is
The sensor cord adapter 10 is connected to the negative electrode of the battery BAT2. The other code of the curl code 12 is
It is connected to one terminal of the resistor R13 in the sensor cord adapter 10 and the positive electrode of the battery BAT2.

Between the positive electrode and the negative electrode of the battery BAT2,
The resistors R13, R14, R15 are connected in series, the common connection node of the resistors R13, R14 is connected to the non-inverting input terminal of the comparison circuit CM1, and the common connection node of the resistors R14, R15 is connected to the non-inversion terminal of the comparison circuit CM2. Each is connected to an inverting input terminal. The comparison circuits CM1 and CM2 constitute a window comparator, and the comparison circuits CM1 and CM2
The input voltage of each inverting input terminal of the resistors R14 and R15
When the voltage between the common connection node voltage and the common connection node voltage between the resistors R13 and R14 deviates from each other, a signal having the same polarity is output, and the input voltage of each inverting input terminal is changed to the resistors R14 and R1.
When the voltage is between the common connection node voltage of No. 5 and the common connection node voltage of the resistors R13 and R14, signals having different polarities are output.

Each output signal of the comparison circuits CM1 and CM2 is
The exclusive OR circuit EXOR is supplied to different input terminals, and the output signal of the exclusive OR circuit EXOR is supplied to the anti-theft tag 9 after being inverted by the inverter INV. The negative electrode of the battery BAT2 is connected to the anti-theft tag 9 by a common potential line.

The sensor 1 for an anti-theft device having such a configuration
1 and the sensor code adapter 10, when the protrusion 16 is inserted into the screw hole 14 and the two electrodes 17 are in contact with the gold-plated bottom of the tubular member 15, the two electrodes 17 are conductive. , The comparison circuits CM1, CM at that time
2 are connected to the resistors R11 and R1.
2, which is between the common connection node voltage of resistors R14 and R15 and the common connection node voltage of resistors R13 and R14. Therefore, the comparison circuit CM1 outputs a positive signal,
Since the comparison circuit CM2 outputs a negative signal, the exclusive OR circuit EXOR outputs an H level signal, and the output of the inverter INV becomes L level (0 V).

When the sensor 11 for the anti-theft device is peeled off the product 13, the protrusion 16 is removed from the screw hole 14, and the two electrodes 17 are separated from the bottom of the tubular member 15,
The two electrodes 17 become nonconductive, and the comparison circuit CM at that time
1, the input voltage of each inverting input terminal of CM2 becomes 0V,
Common connection node voltage of resistors R14 and R15 and resistor R
13 and R14 are on the lower voltage side than between the common connection node voltages. Therefore, the comparison circuits CM1 and CM2 both output a positive signal, and the exclusive OR circuit EXOR outputs L
A level signal is output, and the output of the inverter INV becomes H level.

Here, if the outer skin of the curl cord 12 is peeled off and short-circuited on the way, the input voltage of each inverting input terminal of the comparison circuits CM1 and CM2 becomes the positive voltage of the battery BAT2, and the common voltage of the resistors R14 and R15. The voltage is higher than the voltage between the connection node voltage and the common connection node voltage of the resistors R13 and R14. Therefore, the comparison circuits CM1 and CM2
Output a negative signal together, and an exclusive OR circuit EXOR
Outputs an L level signal, and the output of the inverter INV becomes H level. Therefore, the sensor code adapter 10
The same signal at H level is obtained when the anti-theft sensor 11 is peeled off from the product 13 and the protrusion 16 is pulled out of the screw hole 14 and when the curl cord 12 is peeled off and short-circuited halfway. To the anti-theft tag 9.

FIG. 6 is a block diagram showing a configuration example of the anti-theft tag 9. The anti-theft tag 9 is composed of the IC 1 and an external circuit externally attached to the IC 1, and in a state where the anti-theft device sensor 11 is attached to the product 13,
An L-level (0 V) signal is supplied to the input unit 4 from the sensor code adapter 10 in conjunction with the conduction of the two electrodes 17. In this state, if someone attempts to take out the product 13, the anti-theft tag 9 receives a predetermined signal from a transmitter (not shown) installed at the exit of the counter and outputs an alarm.

Also, if someone tries to avoid this,
When the anti-theft device sensor 11 is peeled off from the product 13 and the anti-theft tag 9 is removed, the two electrodes 17 become non-conductive, and the anti-theft tag 9 sends an H level signal from the sensor code adapter 10 to the input unit 4. Output an alarm. Also, when the outer skin of the curl cord 12 is peeled off and short-circuited during the course, an H level signal is given to the input unit 4 from the sensor cord adapter 10 to output an alarm.

The IC 1 includes an input unit 4 for outputting a signal in response to a signal given from the sensor code adapter 10;
A reset input unit 2 that outputs a signal when a reset signal from the reset switch RS is received, an antenna input unit 3 that receives a signal from a resonance circuit (antenna circuit), converts the signal into a code signal, and outputs the code signal, And a code identification unit 7 for identifying a given code signal and outputting an identification result signal.

The IC 1 also receives a signal and a code (identification result signal thereof) from the input unit 4, the reset input unit 2, and the code identification unit 7, and performs a processing according to the received signal and code. A driving unit 8 that receives an alarm signal from the signal processing unit 5 and drives the light emitting diode LED and the buzzer BUZ; and an oscillation circuit 6 that supplies an oscillation pulse of a predetermined frequency to the antenna input unit 3 and the signal processing unit 5 and the like. ing. The power supply voltage of IC1 is supplied to I1 via a power supply terminal VT connected to the positive electrode of battery BAT1 of the external circuit.
The ground potential is given to each part in C1 and is given to each part in IC1 via a ground terminal GT connected to the negative electrode of battery BAT1.

A signal line from the sensor code adapter 10 is connected to an input terminal of the input section 4, and a common potential line from the sensor code adapter 10 is grounded. One terminal of a reset switch RS of an external circuit of the IC 1 is connected to an input terminal of the reset input unit 2, and the other terminal of the reset switch RS is grounded. A capacitor C4 is connected in parallel to the reset switch RS.

In the oscillation circuit 6, in order to determine an oscillation frequency, a resistor R1 of an external circuit of the IC 1 is connected between two terminals, and a capacitor C1 of the external circuit is connected to one terminal thereof. The input terminal of the antenna input unit 3 has npn
The collector of the transistor Tr1 is connected, and the emitter of the transistor Tr1 is grounded. Transistor T
A resistor R6, the other of which is connected to the positive electrode of the battery BAT1, a resistor R5, the other of which is grounded, and one terminal of a capacitor C5 are connected to the base of r1. The other terminal of the capacitor C5 is connected via a resistor R2 to a parallel circuit of the capacitor C2 and the coil L1, and the other side of this parallel circuit is grounded. The capacitor C2 and the coil L1 constitute a resonance circuit.

The output terminal of the drive section 8 is connected to the cathode of the light emitting diode LED via a resistor R4, and the anode of the light emitting diode LED is connected to the positive electrode of the battery BAT1. The output terminal of the drive unit 8 is connected to a resistor R3, the other of which is connected to the base of a pnp transistor Tr2, the emitter of the transistor Tr2 is connected to the positive electrode of the battery BAT1, and the collector is connected to the other terminal of the battery BAT1. It is connected to one terminal of a buzzer BUZ connected to the positive electrode of BAT1. One terminal of the buzzer BUZ is connected to the anode of the diode D1, and the cathode of the diode D1 is connected to the coil L2, the other of which is grounded. A capacitor C3 is connected in parallel to the battery BAT1.

With this anti-theft tag 9, when set (in the set mode), someone tries to take out the product 13 to which the anti-theft tag 9 is attached from the entrance of the counter where the tag is installed. Then, the resonance circuit of the capacitor C2 and the coil L1 resonates by a radio wave of a predetermined signal transmitted from the transmitter provided at the entrance. This resonance voltage is input to the antenna input unit 3 by driving the transistor Tr1, and is demodulated into a code signal of the alarm input. The demodulated code signal of the alarm input is identified by the code identification unit 7, and the identification result is given to the signal processing unit 5.

In the anti-theft tag 9, in the set mode, somebody removes the anti-theft device sensor 11 from the product 13 and removes the anti-theft tag 9 in order to avoid the above-mentioned situation. , A signal of H level is given from the sensor code adapter 10 to the input unit 4, the signal processing unit 5 recognizes the signal through the input unit 4, sets the anti-theft tag 9 to the alert mode, The drive unit 8 outputs an alarm signal. The alarm signal causes the light emitting diode LED to blink when the output terminal of the drive unit 8 becomes L level at 8 Hz, for example. At this time, the driving unit 8
The sound signal of 4 kHz is superimposed on the L level signal of 8 Hz, the transistor Tr2 is driven, and the buzzer BUZ sounds.

In the anti-theft tag 9, in the set mode, someone tries to avoid the above-mentioned situation by peeling off the outer skin of the curl cord 12 and short-circuiting it midway. Anti-theft sensor 11
When the side is cut and the anti-theft tag 9 is to be removed from the product 13, an H-level signal is given from the sensor code adapter 10 to the input unit 4, and the signal processing unit 5
, The anti-theft tag 9 is set to the alert mode, and the drive unit 8 outputs an alarm signal.
The alarm signal causes the light emitting diode LED to blink when the output terminal of the drive unit 8 becomes L level at 8 Hz, for example. At this time, the driving unit 8 superimposes a 4 kHz sound signal on the 8 Hz L level signal, and
Is driven to sound the buzzer BUZ.

The signal processing section 5 recognizes the alarm input based on the identification result of the alarm input code, sets the anti-theft tag 9 to the alarm mode, and causes the drive section 8 to output an alarm signal.
The alarm signal causes the light emitting diode LED to blink when the output terminal of the drive unit 8 becomes L level at 8 Hz, for example. At this time, the driving unit 8 superimposes a sound signal of 4 kHz on the L level signal of 8 Hz to form a transistor Tr2
Is driven to sound the buzzer BUZ. In the claims, reference numerals are provided for convenience of comparison with the drawings, but the present invention is not limited to the structure shown in the attached drawings.

[0041]

According to the anti-theft sensor according to the first to third aspects of the present invention, even if a strong thin plate-shaped member is inserted into the adhesive portion of the double-sided tape, an alarm is not output and the theft cannot be output. A sensor for the prevention device can be realized.

According to the anti-theft sensor according to the fourth invention, even if a short circuit occurs in the middle of the cord connecting the anti-theft device main body and the anti-theft device sensor, the short circuit can be detected. An apparatus sensor can be realized.

According to the anti-theft device according to the fifth invention, an anti-theft device having the anti-theft sensor according to the first to fourth inventions can be realized.

According to the anti-theft device according to the sixth aspect of the present invention, it is possible to realize an anti-theft device that outputs an alarm when a product to which the anti-theft device main body is attached is taken out of the counter.

[Brief description of the drawings]

FIG. 1 is an external view and a partial cross-sectional view illustrating a sensor for an anti-theft device and an anti-theft tag according to the present invention.

FIG. 2 is a perspective view illustrating an appearance of a sensor for an anti-theft device.

FIG. 3 is a perspective view showing an appearance of a tubular member.

FIG. 4 is a plan view, a longitudinal sectional view, and a side view showing the external dimensions of the tubular member.

FIG. 5 is a block diagram showing a configuration example of a sensor for a theft prevention device and a sensor code adapter.

FIG. 6 is a block diagram illustrating a configuration example of an anti-theft tag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC 3 Antenna input part 4 Input part 5 Signal processing part 9 Anti-theft tag (anti-theft device main body) 10 Sensor code adapter (detection means) 11 Sensor for anti-theft device 12 Curl code 13 Product (anti-theft object) 14 Screw Hole 15 Cylindrical member 16 Projection 17 Electrode (detection means) 18 Double-sided tape BUZ Buzzer CM1, CM2 Comparison circuit EXOR Exclusive OR circuit INV Inverter R11, R12, R13, R14, R15 Resistor RS Reset switch

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Satoru Satoru 1-1-1 Hama, Amagasaki-shi, Hyogo F-term in Kubota Technology Development Laboratory Co., Ltd. 5C084 AA03 AA09 BB04 CC34 DD07 DD74 EE07 HH03 HH08 HH12 HH13

Claims (6)

[Claims] An anti-theft device sensor (11) that is attached to an anti-theft object (13) and detects the attached state and the detached state based on the conduction / non-conduction of an electric circuit. A projection (16) to be inserted into a screw hole (14) for mounting a support leg provided in 13);
The protrusion (16) is provided on the screw hole (14) and the protrusion (16) is inserted into the screw hole (14).
Detecting means (17, 1) for detecting a state of being removed from 4).
0), wherein the detecting means (17, 10) detects the inserted state and the removed state to detect the attached state and the detached state. Sensor for prevention device (11). 2. A bottomed tubular member (15) which is screwed into said screw hole (14) and into which said projection (16) is to be inserted.
The detecting means (17, 10) detects the contact and separation between the tip of the protrusion (16) and the bottom of the tubular member (15), so that the inserted state and The sensor (11) for an anti-theft device according to claim 1, wherein the sensor (11) is adapted to detect a state in which the device is removed. 3. The bottom of the tubular member (15) has conductivity, and the tip of the projection (16) has two electrodes (17) to be electrically connected by the bottom. The sensor (11) for an anti-theft device according to claim 2, wherein the means (17, 10) is adapted to detect the contact and the separation by conduction and non-conduction between the two electrodes (17). 4. A resistor (R1) inserted in the electric circuit.
1) and means (10) provided outside thereof for detecting the presence or absence of a voltage across the resistor (R11), and the means (10) detects absence of the voltage across the resistor (R11).
The sensor (11) for an anti-theft device according to any one of claims 1 to 3, wherein the sensor (11) is configured to detect a short circuit of the electric circuit outside the device. 5. A sensor (11) for an anti-theft device according to claim 1, a receiving means (9) for receiving a predetermined signal in a non-contact manner, and a sensor (1) for the anti-theft device.
Means for outputting an alarm when 1) detects a detached state, when the anti-theft sensor (11) detects a short circuit in an electric circuit, and when the receiving means (9) receives a predetermined signal. (9) An anti-theft device comprising: 6. An anti-theft device further comprising a transmitter for transmitting a predetermined signal to be received by said receiving means (9).