ES2946633A1 - Anti-theft tag deactivator (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Anti-theft tag deactivator made up of an electronic board with: an oscillator (5), configured to generate sinusoidal signals with a preset frequency; a squarer (11) configured to square the binary signals, a signal amplifier (7) and a power stage (8); a control circuit (6) for activating the trip switch; an antenna (4) for emitting the generated electromagnetic pulses. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

Anti-theft tag deactivator

TECHNIQUE SECTOR

The present application refers to an anti-theft label deactivator, which can be coupled to a self-managed purchase system in a store. It allows that when the customer places the product in his cart or basket, properly identifying it for payment, the anti-theft label is deactivated. This ensures that the user does not need to carry out an additional step, generally at the merchant's checkout.

STATE OF THE ART

The existence of patent ES2279666 is known in the state of the art, which refers to an electronic purchase assistance system for cars. This system allows a customer to pick up the items in their cart and make the payment automatically. For this, it comprises a mobile subsystem associated with the cart and a stationary subsystem associated with the establishment. This system has a double security control to reduce theft. A security control is the identification of each article or product by means of an identifying device at the same time as the deactivation of the anti-theft controller element. The deactivation only occurs once the item has been identified, to ensure that the proper charge is made.

The deactivator used in the state of the art adequately fulfills its function, but it is necessary to improve its versatility to allow the user, normally a commercial establishment, to adapt the electronic assistance system to their particular conditions.

The applicant is not aware of any solution to these problems similar to the invention, for deactivation of anti-theft labels, with the same characteristics as the system described in this document.

BRIEF EXPLANATION OF THE INVENTION

The invention refers to an anti-theft tag deactivator according to the claims. His achievements improve and solve technical problems.

This deactivator allows you to instantly deactivate tags of various models and types, such as RF 8.2MHz (all types, shapes and sizes). It allows a deactivation distance of up to 12 cm, this distance depending on the type of label to be deactivated and its relative position with respect to the product barcode.

The invention makes it possible to achieve a portable, versatile deactivator that can be configured according to the type of label used in the store where it is applied. The deactivator can vary, through a software interface, the intensity of the deactivation, the number of pulses emitted and their duration, as well as the detection distance for tripping and deactivation, and the frequency of the electromagnetic pulses by hardware adjustment.

Deactivation control can be performed by communications protocol from any bare-metal system or with any operating system.

For this, the anti-theft tag deactivator is made up of an electronic board with:

- an oscillator configured to generate sinusoidal signals with a frequency preset by hardware;

- a squarer. configured to grid the signals in binary,

- a signal amplifier

- a configured power stage that amplifies the energy of the deactivating electromagnetic pulses;

- a trip switch activation control circuit;

- a tuned antenna for the emission of the generated electromagnetic pulses.

All powered electrically from a battery or a stabilized source of direct current.

The remainder of the specification describes other particular embodiments.

DESCRIPTION OF THE FIGURES

For a better understanding of the invention, the following figures are included.

Figure 1: Diagram of an example application of the deactivator.

Figure 2: Diagram of an embodiment example.

Figure 3: Examples of antenna geometries: A) circular, B) rectangular with curved smaller sides and c) sum or intersection of the above.

MODES OF CARRYING OUT THE INVENTION

An embodiment of the invention is briefly described below, as an illustrative and non-limiting example thereof.

Figure 1 shows an application example of the device, made up of a shopping container (1), which is normally a shopping cart, although it can be a basket. The container (1) has an inlet, a handle and a loading area. It is normally mounted on wheels. As in the state of the art, the container (1) has a label reader (2) and in turn a deactivator (3) of the anti-theft systems. When the tag reader (2) recognizes the item being purchased, the deactivator (3) disables the anti-theft tag arranged in front of the tag reader (2) as long as the anti-theft tag distance requirements are met.

As seen in figure 2, the deactivator (3) is made up of an electronic board with an antenna (4). The deactivator generates a sequence of electromagnetic pulses of high intensity, duration and preset shape. Such an electromagnetic discharge makes it possible to perforate the dielectric of the capacitors that are part of the adhesive anti-theft labels, rendering them useless. The board includes an oscillator (5) that produces the sinusoidal signal, usually with a frequency of 8.2 MHz. This frequency can be preset in the hardware setting, to adjust to the offset of some labels.

This is convenient because, although the tags must be tuned to the nominal center frequency of 8.2MHz, due to the manufacturing method of each supplier, their resonant frequency may not be exactly at that frequency. Therefore, it is preferable to set the oscillator to the actual frequency. To do this, a test can be made from real samples of the labels, randomly and statistically. By trial and error, the final output frequency is thus adjusted to the actual resonance frequency of the label. This operation can be done at the factory, on delivery to the customer or during maintenance if there is a change of supplier.

The signal is controlled by a control circuit (6) that activates a switch or switch, which is responsible for allowing the emission of the high frequency signal in the frame/sequence of pulses of adequate duration and intensity. The resulting signal, therefore, passes through a signal amplifier block made up of a preamplifier (7) followed by a power stage (8) configured to increase the amplitude of the pulses. In the preamplifier (7) it is amplified in voltage and intensity and from the power stage (8) where, fed by high voltage DC voltage from a converter (9), it attacks the emitter output circuit, with previous adjustment (10). of impedance and tuning (resonance) in final loop, being converted back to sinusoidal. All this fed in direct current from a stabilized source (12). The preamplifier (7) can be integrated into the power stage (8).

This previous adjustment (10) is carried out by means of a variable capacitor or trimmer, confirming the characteristics of the output pulses with an oscilloscope (connected by induction). The adjustment seeks to achieve the maximum amplitude of the pulses and is normally carried out at the factory.

The power stage (8) is the one that directly feeds the output loop. It is a system with MOSFET transistors in a half-bridge configuration, fed through an impedance transformer with an intermediate tap. It is responsible for increasing the amplitude of the pulses.

The conditions of the deactivation electromagnetic pulse train can be controlled by the control circuit, in order to adapt them to the type of tags to be deactivated. Thus, the quantity, width and sequence of the deactivation electromagnetic pulse train can be modified.

The set is made up of passive elements, such as resistors, coils and various, fixed and variable capacitors, as well as various semiconductors such as BJT and MOSFET transistors, rectifying diodes and a programmable microprocessor, with high-speed logic gate modules and impedance transformers, all mounted on a printed circuit with layout techniques and shields designed to not be sensitive to the emitted pulses themselves. All the elements are fed in stabilized direct current.

Figure 3 shows some examples of antenna (4) or emitter loop, depending on the type of label to be deactivated, the deactivation distance and the frequency of resonance. The solution of figure 3B is circular, that of figure 3A is rectangular, with curved smaller sides and figure 3C shows a shape corresponding to the intersection of both geometries. Other geometries are possible.

The example in Figure 3A achieves more field at the ends. The example of figure 3B, on the other hand, concentrates the field more, while figure 3C distributes it more throughout the area of influence. These three examples optimize the radiation towards the outside of the equipment.

Thus, Figure 3A is designed for cases where the label may be in different places on the products. If the label is after the barcode or always at the same point, the solution in figure 3B is ideal.

Optionally, in the case of generating sinusoidal signals, a squarer (11) configured to square the signals in binary can be directly integrated at the output of the oscillator. Thus, the signal is gridded in binary (double wave 180° out of phase).

Claims (1)

1- Anti-theft tag deactivator, characterized in that it comprises an electronic board with: an oscillator (5), configured to generate sinusoidal signals of a preset frequency; a signal amplifier block made up of a preamplifier (7) followed by a power stage (8) configured to increase the amplitude of the pulses; a control circuit (6) for activation of a trigger switch; an antenna (4) for emitting the generated electromagnetic pulses. 2- Deactivator of anti-theft labels, according to claim 1, characterized in that it comprises a squarer (11) between the oscillator (5) and the signal amplifier block. 3- Anti-theft label deactivator, according to claim 1, characterized in that the frequency of the oscillator signals (5) is adjustable by hardware. 4- Deactivator of anti-theft tags, according to claim 1, characterized in that the antenna (4) has a selected shape between circular, rectangular with curved smaller sides and the intersection of both.