JPH0419933A - Robbery preventive apparatus - Google Patents

Abstract

PURPOSE:To lower electric power consumption of a tag apparatus by detecting the movement of an object article to be protected through the movement of a ball in the tag apparatus attached to the article and giving the alarm. CONSTITUTION:A tag apparatus 2 which is attached to an object article 1 to be protected receives electric wave radiated in a prescribed region with a receiver part 9 and operates a robber alarm 3 by its output. The electric current for the operation of the alarm 3 is supplied from a battery 4 through a movement sensor part 17. The movement sensor part 17 is composed of a movement sensor 18 and a self-maintaining circuit 19. The movement sensor 18 is composed of a plurality of electrodes and a plurality of divided electrodes in the inside walls and a case which keeps a freely movable conductive ball in the inside. Owing to the movement of an object article to be protected, the ball moves and switches the switching contact I or II and thus the alarm 3 becomes in operational state.

Description

DETAILED DESCRIPTION OF THE INVENTION FIELD OF INDUSTRIAL APPLICATION The present invention relates to an anti-theft device that detects when a protected item on display is illegally taken out of a controlled area.

BACKGROUND OF THE INVENTION FIG. 6 shows a protected item 1 and a tag device 2 attached to the protected item 1. As shown in FIG. 7, the tag device 2 has a built-in alarm device 3, a battery 4, etc., and the operation of the alarm device 3 is normally turned off by a switch section 5. An antenna 6 that radiates radio waves B to a specified area A is installed near the entrance 8 of the store where the protected item 1 is displayed, as shown in FIGS. 8 and 9. 7 is a checkout table where money and protected items 1 are exchanged between the customer and the prefectural government. The transmitter lO that provides a signal to the antenna 6 is connected to a power amplifying section 11 as shown in FIG.
, an oscillation circuit 12 and a power supply 13. The UHF band is used as the frequency of the radio wave B, and a Yagi antenna with several elements is used as the antenna 6.

In a normal sales format, the tag device 2 is removed from the protected item 1 at the checkout table 7 by the prefectural government or by a special procedure, and only the product is handed over to the customer. from checkout table 7, pass through designated area A, and exit the store through entrance 8.

In a shoplifting situation, when the protected item 1 with the tag device 2 passes through the specified area A, the receiving section 9 of the tag device 2 detects the radio waves 6 emitted from the antenna 6 and operates the switch section 5. Then, alarm 3 is turned on and an alarm sounds in the vicinity, immediately notifying the prefectural government that shoplifting has occurred.

Problems to be Solved by the Invention The battery 4 built into the tag device 2 consumes power even during exhibition, and it is necessary to reduce power consumption as much as possible in order to achieve stable operation over a long period of time. It is.

Furthermore, in anti-theft devices using frequency bands U) (F), the installation of the antenna 6 and elements are devised so as to limit the prescribed area A to a narrow area near the entrance/exit 8, but it is sufficiently narrow. It is difficult to specify only one area, and it is difficult to use a sufficiently short distance from the checkout table 7 to the entrance 8.

Furthermore, if a fraudulent act occurs, such as passing through the designated area A while covering the tag device 2 with a simple shielding material, the radio wave B will be completely blocked by the shielding material and will no longer reach the receiving unit 9. As a result, theft could not be prevented.

In order to limit the prescribed area A to a narrower area than before or to detect any fraudulent activity caused by the use of a shielding material, it is preferable to lower the operating frequency radiated from the transmitter 10.

However, if the operating frequency is lowered, malfunctions of the tag device 2 due to noise will increase, so the tag device 2 is equipped with various verification circuits, etc., so that it responds only to specific codes transmitted from the transmitter 10. However, if a verification circuit or the like is provided in this way, the power consumption of the tag device 2 will increase and the battery 4 will be consumed during the exhibition, and stable operation over a long period of time cannot be expected. A problem occurs.

An object of the present invention is to provide an anti-theft device that can reduce power consumption of tag devices on display.

Means for Solving the Problems The theft prevention device of the present invention comprises: a transmitting device that radiates radio waves to a specified area; a tag device attached to an item to be protected that detects the radio waves and generates an alarm; A movement sensor part is installed in the power supply circuit and starts energizing when it detects that the tag device has been moved from the display position, and the movement sensor part is enclosed in a conductive ball and this ball is movable. a common electrode that the ball contacts is arranged on at least one of the inner side of the lower surface or the inner side of the upper surface, and a plurality of divided electrodes are arranged on the inner side of the peripheral surface connecting the lower surface and the upper surface; Consists of an electrode and a self-holding circuit that is connected to the divided electrode and maintains the set state,
The relationship between the interval between the divided electrodes and the diameter of the ball is set so that there is no conduction between adjacent divided electrodes through the ball, and the adjacent divided electrodes are alternately connected to the set input and reference potential of the self-holding circuit. It is characterized by what it did.

Effect: According to this configuration, the movement sensor section turns off the power supply circuit of the tag device until the protected item is lifted from the display position. When the protected item is lifted, the movement sensor unit starts energizing the tag device's power circuit, and when the protected item passes through the specified area, the tag device detects radio waves and issues an alarm.

The movement sensor unit has a common electrode, a divided electrode, and a conductive ball enclosed in a case, and when the object to be protected is lifted from the display position, the ball moves within the case and inputs instructions to the self-holding circuit reliably. Apply.

EXAMPLE Hereinafter, an example of the present invention will be described based on FIGS. 1 to 5. Components having the same functions as those shown in FIGS. 6 to 9 showing the conventional example will be described with the same reference numerals.

FIG. 2 shows the anti-theft device of the present invention, in which the frequency used is changed to 12.5 kHz and the antenna 6 is replaced by a loop coil 14. The loop filter 14 radiates a 12.5 kHz signal to a defined area A near the entrance/exit 8.

The antenna of the receiving section 9 of the tag device 2 has also been changed to a loop coil 15. A movement sensor section 17 that controls power supply to the switch section 5 and the alarm device 3 is interposed in the power supply circuit of the tag device 2 . As shown in FIG. 3, this movement sensor section 17 is composed of a movement sensor 18 and a self-holding circuit 19. The movement sensor 18 is constructed as shown in FIGS. 4 and 5.

A conductive ball 21 is enclosed in a case 20 that is composed of a lower case 20a and an upper case 20b that closes an opening on the upper surface of the lower case 20a. There are balls 2 on the inside of the bottom and inside of the top of the case 20! Common electrodes 22a and 22b are provided in contact with the common electrodes 22a and 22b, and a plurality of divided electrodes 23a to 23g are provided on the inside of the circumferential surface of the lower case 20a. The common electrodes 22a and 22b are connected to each other by the contact piece J of the common electrode 22a coming into contact with the bent piece K of the common electrode 22a when the upper case 20b is attached to the lower case 20a, as shown in FIG. Common electrode 22a- in the electrical circuit diagram
b. Split electrodes 23a, 23c, 23e, 2
3g is connected to each other by the integrally formed connecting piece M, lead wire N, and connecting piece O, and the divided electrode 23b is connected to the first divided electrode 23a-ce-g in the electric circuit diagram shown in FIG. , 23d, and 23f are integrally formed connecting pieces P1. They are connected to each other by P2 to form second divided electrodes 23b-d-f in the electrical circuit diagram shown in FIG. Here, a capacitor 26 is interposed between the common electrodes 22a-b and the reference potential, and the second divided electrodes 23b-d-
f is connected to a reference potential. The set terminal S of the self-holding circuit 1B, which is pulled up to a high level by the resistor 27, is connected to the first divided electrodes 23a-c-e-f.

Note that here, adjacent divided electrodes 23a and 23b, 2
3b and 23C, 23c and 23d, 23d and 23e,
23e and 23f.

The spacing between the divided electrodes 23a to 23g and the ball 2 are adjusted so that there is no conduction between the divided electrodes 23a and 23g through the ball 21.
The size of the diameter of 1 is set. Also, here, the connecting pieces P, P2 run along the corners of the bottom of the lower case 20a, but because of the curved surface of the ball 21, the connecting pieces P,
, P2, the common electrode 22a is connected via the ball 17,
There is no conduction with 22b.

With this configuration, the first divided electrodes 23ac-e
-g, a common electrode 22a, a first opening/closing contact I formed by 22b and a ball 21, and a second divided electrode 23b.
-df, the common electrodes 22a and 22b, and the second switching contact (2) formed by the ball 21 do not turn on at the same time. During the exhibition, the self-holding circuit 19 is reset in advance and the set terminal S is pulled up to a high level. At this time, even if the first switching contact I is in the on state, the capacitor 26 has been charged up and the set terminal S is maintained at a high level. When the self-holding circuit 19 is reset, the opening/closing section 28
maintains the state in which power is supplied from the battery 4 to the off state.

When the protected item 1 is lifted, the ball 21 moves inside the case 20, causing the first switching contact I and the second switching contact ■ to repeat opening and closing, and when the second switching contact ■ turns on, the capacitor 26 charges are discharged and the first switching contact I
When turned on, a charging current flows through the resistor 27 to the capacitor 26, the set terminal S is inverted to low level, the self-holding circuit 19 is set, and the opening/closing part 28 is inverted to the energized state.

Here, when the tag device 2 is slightly tilted, the ball 21 moves inside the case 20, and the first opening/closing contact I and the second opening/closing contact H open/close, and the self-holding circuit 19 is reliably set. Then, energization can be started through the opening/closing part for two days.

In the above embodiment, the common electrodes 22a and 22b were arranged on the inside of the bottom surface and the inside of the top surface of the case 20, but by considering the diameter of the ball 21 and the interval between the inside of the bottom surface and the inside of the top surface inside the case 20, A similar effect can be obtained by simply providing a common electrode on either the inside or the inside of the upper surface.

In the above example, the case where the operating frequency is 12.5 kilohertz, which is a very low electric field, was explained as an example, but even when the operating frequency is as high as the UHF band, the tag device on display can be 2. Power consumption can be reduced.

Effects of the Invention As described above, according to the present invention, there is provided a movement sensor section which is interposed in the power supply circuit of the tag device and starts energization when detecting that the tag device has been moved from the exhibition position. a conductive ball, a common electrode in which the ball is movably enclosed, the ball comes into contact with at least one of the inner side of the lower surface and the inner side of the upper surface, and the inner peripheral surface connecting the lower surface and the upper surface; a case in which a plurality of divided electrodes are arranged, and a self-holding circuit that is connected to the common electrode and the divided electrode and maintains the set state,
The relationship between the interval between the divided electrodes and the diameter of the ball is set so that there is no conduction between adjacent divided electrodes through the ball, and the adjacent divided electrodes are alternately connected to the set input and reference potential of the self-holding circuit. Therefore, there is no directionality in the detection of the movement sensor unit, and movement in any direction can be detected with extremely high precision.The power consumption of the tag device on display can be significantly reduced, and it can be used for a long period of time. You can expect stable operation over the long term.

Moreover, in the event that the protected item is lifted, it is possible to reliably start energizing each part of the tag device, and it is possible to avoid a decrease in reliability caused by turning off the energization while on standby. .

[Brief explanation of drawings]

Fig. 1 is a perspective view of a tag device used in the anti-theft device of the present invention and the object to be protected to which it is attached, Fig. 2 is a configuration diagram of the anti-theft device of the present invention, and Fig. 3 is a movement of the device. A configuration diagram of the sensor section, FIG. 4 is an exploded perspective view of the movement sensor of the device,
Fig. 5 is a plan view of the movement sensor of the same device with the bottom of the case opened, Fig. 6 is a perspective view of a tag device used in a conventional anti-theft device and the object to be protected to which it is attached, and Fig. 7 1 is a block diagram of a conventional anti-theft device, and FIGS. 8 and 9 are a schematic cross-sectional view and a plan view of the vicinity of the entrance and exit of a store. DESCRIPTION OF SYMBOLS 1... Product to be protected, 2... Tag device, 4... Battery, I7... Movement sensor section, 18... Movement sensor, 1
9... Self-holding circuit, 20... Case, 21...
Ball, 22a, 22b... Common electrode, 23a-2
3g...divided electrode, 2B...capacitor.

Claims (1)

[Claims] 1. A transmitting device that emits radio waves in a specified area, a tag device that is attached to the protected item and that detects the radio waves and generates an alarm, and a tag device that is installed in the power supply circuit of the tag device and that allows the tag device to be moved from the exhibition position. The movement sensor part is provided with a conductive ball and the ball is movably enclosed in at least one of the inside of the lower surface or the inside of the top surface. A case in which a common electrode with which the ball comes into contact is arranged and a plurality of divided electrodes are arranged inside a peripheral surface connecting the lower surface and the upper surface, and a case that is connected to the common electrode and the divided electrode and held in a set state. The relationship between the interval between the divided electrodes and the diameter of the ball is set so that there is no conduction between adjacent divided electrodes through the ball, and the adjacent divided electrodes are alternately self-held. Anti-theft device connected to the circuit's set input and reference potential.