JPH06502733A - Method of manufacturing a tag comprising a resonant circuit capable of being activated and deactivated and activation and deactivation of said resonant circuit - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] A method of manufacturing a tag including a resonant circuit capable of being activated and deactivated, and Activation and deactivation of said resonant circuit The invention can be made into an activated state and an inactive state according to the prerequisite of claim 1. The present invention relates to a method for manufacturing a tag.

Public knowledge to secure items from theft, especially in self-service stores A very popular method of The use of carefully crafted electronic safety devices that contain radio signals. The item is special The tag is marked with one or more coils and keys. Is it made so that the resonant circuit created by the connection between the capacitors is arranged? , but some coils and capacitors may be used in a single circuit. Wear. These elements are usually made of insulating plastic or similar material. a conductive layer or aluminum on this support layer. Placed on only one side of the support layer or on both sides. Because the support layer is used This is because it acts as a dielectric medium within the capacitor. This circuit has a high quality factor (Q value).

The transmitter uses the resonant frequency of a resonant circuit or a frequency that is systematically varied within a certain range. Because of the high Q value of this circuit, the receiver or this resonant circuit emits a signal with a wave number. The resonant circuit can be detected when the natural frequency is emitted.

Items equipped with a tag with a resonant circuit are paid at the exit of the store where the account is set up. These tags must be removed or torn when passing through the area. if If this is not done, an attempt to cross the controlled area is received. device is detected and an alarm is activated.

A resonant circuit can be modified by applying an electromagnetic field that generates a current in the circuit. conductive breaks that can be burned out more easily than other parts of the circuit. Provide certain parts with reduced area or e.g. plates of capacitors A section is provided that fosters a particularly small distance between the electromagnetic The strength of the field and therefore the modification of the circuit can be made to be of limited magnitude. .

By attaching a tag, whether the tag's resonant circuit has a specific natural frequency or not. is subjected to an electromagnetic field in order to detect the It shall not cause any modification of the magnetic field or resonant circuit. On the other hand, modifying the circuit The electromagnetic field provided for In this way, the part of the capacitor to be destroyed must be must be well defined or required to have uniform dimensions. do not have. Approximately 3 μm in the dielectric medium located between the capacitor plates in the part to be destroyed. It is considered appropriate to give a thickness of

A thickness thinner than this may reduce the Q factor of the circuit.

Instead of reducing the thickness of the dielectric medium within the capacitor in a single section, The entire plate area of the passitor is covered by a dielectric medium of approximately 3 μm. It can be done. However, the production of such dielectric media must be controlled to have sufficiently high precision. It is difficult to control it.

From U.S. Pat. No. 4,021,705, the conductive paths within the coil are This conductive path is selected by making it extremely thin in minutes and applying a strong electromagnetic field. Is there a way to destroy the coil in the tag's resonant circuit by destroying the Are known.

The method of modifying such a resonant circuit is virtually impossible! When not covering , requires an electromagnetic field strong enough to have a detrimental effect on surrounding objects, and thus This method is not applicable to

U.S. Pat. No. 4,498,076 discloses a conductive layer (usually made of aluminum). or other conductive materials can also be used as capacitor plates) and intermediate The dielectric medium is compressed by a piston to reduce the thickness of the dielectric medium in a small area inside. is smaller than outside the range, and thus even more than outside this range. Resonant cycles by allowing breakdown to occur in the capacitor at low voltages. Repairs should be made so that a small distance is created between the two capacitor turfs in the path. A method of manufacturing a resonant circuit suitable for performing positive resonant circuits is disclosed.

This method has many drawbacks. This is because, in this case as well, within a limited range Dimensions of the required dielectric medium, i.e. 3 μm compression or piston and capacitor Obtain extremely accurate 90° angles between planes and usable reproducible results. This is because it requires precisely controlled pressure.

This compression is done on a hard rubber substrate, which may introduce other inaccuracies during manufacturing. It is considered that

A more detailed examination of the circuits manufactured by the last-mentioned method is provided by a number of circuits already available. destroyed during the manufacturing process and thus not well defined by this method resulting in the thickness of the dielectric medium, resulting in - there is a huge variation in the magnitude of the Q value, - the energy required to bring it to the inactive state; energy is not well defined, The thickness of one conductive layer is reduced, and this - despite one spark failure as explained below. The capacitor acts as a single capacitor (self-healing capacitor). As the conductive layer continues to be compressed, destruction becomes uncertain; - during compression the circuit may be destroyed. The risk of breaking increases with the size of the piston, so the size of the part to be compressed must be strictly restricted, A substrate undergoing compression changes its properties over time, Temperature changes in the manufacturing area create problems when using the applied tools; In this way, since a poorly formed product is produced by this method, 2 between two capacitor plates or other voltage holding elements in the circuit described. There is a clear need for other methods of reducing the thickness of the insulating layer.

The present invention allows the device to be disconnected by slight pressure by impact against the insulating material placed on the tag. The thickness of the edge is reduced to a predetermined thickness with great precision and a low intensity electromagnetic field is applied. or by applying an electric field, a range is formed that causes destruction. The present invention provides a method.

The method described above can be applied to one or more capacitors forming part of a resonant circuit. This includes heating a range of In this way, the dielectric medium softens or melts. The dielectric medium is heated with great precision by applying a slight pressure to the heated area. A region having a predetermined thickness of the layer is formed.

The present invention is characterized by the temperature, impact range dimensions, impact time, and Inexpensive, including some parameters such as the magnitude of the applied pressure and the shape of the impact range. It provides a technically simple and easy-to-understand method.

The invention uses laser, ultrasonic, microwave or other suitable means as the heating element. The last step is that it gives a completely free choice of heating method as it is available in several stages. Emphasis is placed on the pressure required on the dielectric medium material to the known prior art. The pressure is substantially lower than that at

Therefore, the obtained manufacturing results have a low reject rate and a well-formed and processed area. The thickness of the dielectric medium layer has greater precision and uniformity than known prior art techniques. can be obtained.

In this way, the strength of the electromagnetic field required to modify the resonant circuit can be precisely determined. I can do that.

In connection with the resonant circuits treated by the present invention, the required electromagnetic field strength is significantly lower. For example, it can be destroyed by an electromagnetic field weaker than that of a piezoelectric crystal in a gas igniter. may occur within a predetermined range.

A variant method for forming a region in a dielectric medium with a desired thickness is to It is an object of the present invention to provide a dielectric medium having pores that allow the pores to form a dielectric medium. Insert the desired thickness into this hole. An electric medium is placed, and for this area, the magnitude of the desired electromagnetic field is Given only one thickness of the corresponding dielectric medium, destruction is thus ensured. It will be done so that

Instead of a dielectric medium, a conductive connection of suitable thickness to one capacitor plate can be used. Pieces of electrically conductive material can be placed in a connected state.

This capacitor is finished by compressive stress.

In connection with the method described above, on one cava soter plate as described above, this Placing pieces of conductive material of suitable size electrically connected, thereby creating a pressure dielectric medium layer or capacitor plate, and other capacitor plates. The dielectric medium may also be applied to the substrate at the same time or during the operation process of the pond. Pores in quality can be avoided.

Also, these variant methods are great for giving a reasonable range to be destroyed. It is characterized by accuracy.

The invention will be explained in detail below with reference to the accompanying drawings, or Inside, 1 [J is a plan view of the resonant circuit forming part of the tag, and FIGS. 2 and 2A are 1 shows a cross-sectional view through a portion of the capacitor in the circuit of FIG. Figure 3 shows a cut across a number of conductors that are part of the windings of the coil in the circuit of Figure 1. Figure 4 shows the dielectric medium layer between the capacitor plates or the capacitor tarp. A cross-sectional view across a capacitor such that it has a thickness with dimensions proportional to the thickness of the rate. Figure 5 shows the dielectric medium layer between the capacitor plates or the capacitor plate. A cross section across a capacitor that has a relatively small thickness compared to the thickness of the capacitor. FIG. 6 shows a precisely dimensioned piece of dielectric medium or 5 shows a cross-sectional view across a capacitor with a hole in a dielectric medium configured to Figure 7 shows a precisely dimensioned piece of conductive material to be placed inside. a cross-sectional view across a capacitor with a hole in a dielectric medium; FIG. 8 shows a piece of conductive material assembled by being pressed into a dielectric medium. Figure 2 shows a cross-sectional view across a capacitor.

The conductive material in the resonant circuit shown in Figure 1 is preferably aluminum. Or other conductive materials can be used as well. This conductive layer is acid-etched. The supporting plastic material 2 is manufactured by It can be placed on both sides of the plastic material 2. In the latter case the supporting material is It can directly act as a dielectric medium within the capacitor 3.

If the conductive layer is placed on only one side of the support layer 2, it is placed on the dielectric medium or the support layer. The conductive layer or dielectric medium is then applied to the conductive layer or dielectric medium. must be done as it is done. One end 5 of the coil 4 is directly connected to a capacitor. -3, while the other end 6 is connected to another plate, e.g. This plate is closed by, for example, as indicated by the dash-dotted line 4A. The windings of the coil are placed between an insulating layer or a conductive path between the windings of the coil. by leading a conductive path across the line, or - in a supporting layer with conductive layers on both sides. Related - capacitors by leading the connections through the plastic layer The plate is connected to the one plate of the plate.

Conductive layers can also be produced by cutting blanks.

FIG. 2 shows that a capacitor plate 7 formed in a conductive material is connected to a dielectric medium 8. FIG. 4 shows a cross-sectional view through portions of the capacitor spaced apart by a distance. predetermined In a plurality of areas, or in just one area, this dielectric medium is e.g. a heating element 9 is pressed, by which a suitable insulating material is subjected to compression; It is possible to reduce the thickness of the dielectric medium to the intended dimensions by means of slight pressure being done. Can heating be done by heating elements and energy? For example, using other means such as ultrasound, lasers or microwaves to transmit Can be used. Pressure against the dielectric medium is applied by heating elements or by the surface of the capacitor. This can be done by applying a vacuum or overpressure to.

The impact on the dielectric medium is also applied after the final assembly of the resonant circuit as shown in Figure 2. Refer to Figure 2A and immediately before applying the capacitor plate on one side of the dielectric medium. It can be applied to the negative side of the dielectric medium.

Figure 3 shows a portion of the cross-section across the coil of the resonant circuit on the tag; Each winding of the coil IO is arranged on the dielectric medium layer 11, and this portion C The intended thinness applied by the method described herein on top of multiple windings IO Another dielectric medium N12 of thickness is arranged, and a conductive layer 13 is arranged thereon. . Shocking with an appropriate electromagnetic field will cause destruction, followed by subsequent shorting or generation of the coil. Jiru. A plate 13 of conductive layer with a dielectric medium layer 12 covers any area on the coil. can also be arranged in sections, this plate having only two or more windings I It only needs to be covered or placed over the inlet of the coil.

Figures 4 and 5 show how such a capacitor can "self-repair" after destruction. Figure 3 shows a cross-sectional view through the capacitor to show how it returns.

FIG. 4 shows a capacitor in which the dielectric medium material 15 is substantially thicker than the plates 16. - is shown. The holes caused by spark destruction are more capacitive than the dielectric medium material 15. It is large within the tar plate 16. Therefore, the two capacitor plates 16 are connected to each other. therefore, the capacitor operates as a capacitor and therefore remains insulated. A stable short circuit is made as given.

Figure 5 shows an example of a capacitor being destroyed by a deactivation signal in a stable manner. It shows. In this case the dielectric medium layer is much thinner than the capacitor plate 16. The holes in the metal plate 16 after fracture are smaller than the holes in the dielectric medium layer 15. , thus providing a stable short circuit.

Finally, Figures 6, 7 and 8 may have similar parts or the same reference numerals. to create elements in a resonant circuit for activating and deactivating the tag. 1 shows a variant method of building. For example, the plate shown in Figure 6, which has a thickness of 10 μm, The electrolytic medium 18 is provided with holes 19 in which the intended thickness, for example 3μ, is provided. A small piece of dielectric medium 20 with a thickness of m is placed. attraction to the air The electric constant is extremely small, and the portion of the hole I9 that is not occupied by the dielectric medium 20 is filled with the dielectric medium. It is made to have no significance compared to the corresponding dimensions of the material.

Instead of a dielectric medium, a conductive material is electrically connected to the capacitor plate 17 strip 21 is inserted as shown in FIG. This can be done in such a way that the exact distance contemplated in between can be obtained.

Finally, FIG. 8 shows a strip of conductive material in conductive connection with plate 17. 21 is pressed into the dielectric medium material I8 by pressure, and here again the capacitor plate is The precise distance contemplated between the ports 17 is obtained.

In situations where the tag is placed on or in the item to be attached, It may be desirable to be able to activate the resonant circuit of the device. This thing is Can be done in the same way as is done to perform deactivation of a resonant circuit . This is because the resonant circuit is tuned to a natural frequency after activation of the circuit during tag assembly. This is because it has a sheared natural frequency. Tag inoperable If the electromagnetic field must also be By applying a magnetic field, a connection between two ends can be created by a current path being interrupted. connections may be made and lost connections may be made.

Afterwards, the resonant circuit is again interrupted by an even stronger electromagnetic field as described above. be able to. By activating the resonant circuit, the natural frequency of this circuit can be modified. Right or wrong is done. Even if the circuit is not activated, the resonant circuit or Sea tered capacity. Therefore, tag deactivation is It can be done with two frequencies to detect the status of the tag.

F/63 FI65 international search report 1@1. %s+, #1A) e’1ctlla*Nv PCT/DK 91100 3461m, 1. ．． 21. Ill””AIpifall, 1,116. PCT /D taste +91100346 international investigation report

Claims (8)

[Claims] 1. Actuation with at least one coil and at least one capacitor A method of manufacturing a tag comprising a resonant circuit that can be activated and deactivated, the tag comprising: In particular, when the tag leaves the sales store, it must be accounted for. the control of said tag is configured to be placed on or in an item such as a transmitter and a suitable receiver; In that case, the transmitter generates signals of several different frequencies, and these frequencies are connected to a resonant circuit. through the natural frequency of the channel and the receiver records the presence of such a resonant circuit. The capacitor plate is arranged in one or more areas. the dielectric medium material disposed between the conductive material has a thickness that is less than the thickness of the conductive material; In the method for manufacturing the tag, the dielectric material disposed on the tag is The thermal shock on the medium material (2, 8, 15) causes the heated dielectric medium material ( 8) The thickness can be reduced by applying a weak electromagnetic or electric field with a slight pressure. characterized in that a range is provided in which the damage can be reduced in such a way that destruction occurs. How to manufacture tags. 2. Destruction connects the coil (4) to the capacitor (3) and causes the coil (4) to connect to the capacitor (3) before activation. A resonant circuit (1 ) to the extent that said resonant circuit (1) is activated such that a connection is formed that forms a A method as claimed in claim 1, characterized in that: 3. In order to deactivate the resonant circuit (1), the resonant circuit is connected to the capacitor. After the destruction of the tarplate (7, 36) said resonant circuit is destroyed by a short circuit. Sometimes there are multiple ranges between the capacitor plates (7, 16) in the resonant circuit (1). A thinner insulating layer (8, 15) is formed outside these areas. Claim 1, characterized in that the plate is located between the two plates. method described in. 4. In order to deactivate said resonant circuit, a plate (13) of electrically conductive material is placed on the core. The thickness is thinner than the insulating layer (11) of the tag across the numerous conductors (10) in the facing an insulating layer (12) having a plurality of windings of the coil. ) of a claim characterized in that it is made to be short-circuited by destruction across the The method described in Scope No. 1. 5. The deactivation range in the resonant circuit (1) connects the lead-in wire to the coil (4). It is characterized by being made to occur by passing them in close contact with each other. 1. The method as claimed in claim 1. 6. having at least one coil and at least one capacitor Manufacture a tag containing a resonant circuit that can be made into an activated state and deactivated. a method in which an account is set when said tag is specifically removed from a sales store; These items must be placed on or in such items. Control of the tag is carried out by a device that includes a transmitter that emits electromagnetic waves and a suitable receiver. The transmitter then emits a signal with several frequencies, and these frequencies through the natural frequency of said resonant circuit, and when said receiver has such a resonant circuit. The capacitor is placed between the plates of the capacitor. the thickness of the conductive material in one or more areas where the dielectric medium material is In the method of manufacturing the tag, the tag is adapted to have a thickness less than One or more holes (19) are provided in said dielectric medium (18), at which point A small piece of dielectric medium with a uniform thickness suitable for activating and deactivating at any location. The capacitor plate (17) is then placed in the dielectric medium. manufacture a tag characterized in that it is adapted to be placed on a material (18); Method. 7. One or more holes (19) are provided in said dielectric medium (18), and A small piece of conductive material with a thickness suitable for activating and deactivating the piece (21) is in conductive connection with one capacitor plate (17). and then the capacitor plate (17) and the dielectric medium (18) Claim 6, characterized in that the device is configured to be assembled. Method. 8. one or more having a thickness suitable for activating and deactivating A piece of electrically conductive material (21) is in electrically conductive connection with said capacitor plate (17). after which the capacitor plate is moved by a slight pressure. said dielectric medium material ( Claim 7, characterized in that the device is press-fitted into the The method described.