JPH03503219A - Electronic Article Surveillance System with Improved Discrimination - 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] Electronic Article Surveillance System with Improved Discrimination (Annex) Attached document containing a total of 13 pages regarding the calculator list.

TECHNICAL FIELD This invention relates generally to electronic security systems, and more particularly to an improved electronic article surveillance system. Regarding tem.

Various electronic object surveillance systems are used to limit the illegal removal of objects from certain buildings. A system has been proposed and implemented. One common form of this is retail stores, books An electronic article monitoring system installed near the exits of buildings and similar locations. Ru. However, electronic article monitoring systems can be used, among other applications, to It can also be used for process and inventory management by detecting items as they pass through the system. can.

Regardless of the application involved, such electronic article surveillance systems generally have a common It works on a principle. Items to be monitored are provided with tags (of various different types). The tag has a circuit (resonant circuit) that reacts with the applied radio frequency field. child A transmitter and a transmitting antenna are provided to form a field of A receiver and a receiving antenna are provided to detect disturbances caused by the noise. If tag resonance When a circuit passes between a transmitting antenna and a receiving antenna (both antennas are generally (placed near the exit of the field), influences the field formed and is detectable. An event occurs within the receiver. This is then used to issue appropriate alarms. Ru. Other systems of this general type include New Chassis, Troff. is available from manufacturers such as Checkpoint Systems, Inc.

Such systems have been proven to be effective in both security and inventory and process control. However, certain enhancements to such systems have been found desirable. most Also important is the range of possible errors ( e.g. false alarms), in particular the presence of tags (indicating the presence of the protected article) and electronic articles. Reduces errors in distinguishing between other sources of interference that may be in the vicinity of the surveillance system There is an ever-present need to do so. measures taken to improve the accuracy of the system. Any method available shall attempt to reduce such undesirable consequences. Dew.

Recently, the differences between different types of tags based on the differences in the resonant circuits involved have been accurately determined. There is an interest in providing an electronic article surveillance system with sufficient resolution to identify It's happening. Different types of tags differ depending on the configuration of the resonant circuit they contain. It has long been recognized that different types have different "signatures" (responses). example For example, the resonant circuit of a so-called "hard" tag generally comprises a specific label device; such as hanging tags and labels that result in differences in component dimensions and configurations. Other forms of tags will generate a somewhat stronger signal. As a result, different Analysis of the signature allows for the differentiation of different forms of tags. It has become conceptually possible to distinguish between labels and labels. However, to date, the available Stems do not have the sensitivity to reliably detect this difference.

(Summary of the invention) Therefore, providing an electronic goods auditing system with improved accuracy and reliability. This is the first object of the present invention.

Able to react accurately and reliably to increased proportions and differences in labels or tags encountered It is also an object of the present invention to provide an electronic goods audit system.

The electronic article audit system uses tags that pass near the electronic article audit system. An electronic article auditing system that reliably distinguishes between signals generated by interference and potential sources of interference. It is also an object of the present invention to provide.

Electronic article monitoring system that can identify differences between different types of tags and labels It is also an object of the invention to provide.

Individual and adjustable addressability of tags or labels according to desired operating parameters It is also an object of the present invention to provide an electronic article monitoring system that allows Ru.

These and other objectives are achieved by the present invention in conjunction with the achievement of the above-mentioned goals. We offer several different improvements to conventional electronic article monitoring systems. This is achieved by

For example, the transmitting antenna for the system may be a conventional single wire or single coaxial cable. Instead of a loop antenna, use a “paired lead” loop antenna configuration. Ru. The term "pair leads" applies not only to the currently preferred twin-axial cables, but also to , and other two flat wires, such as twin coaxial cables called "ship lines". Also included are row lead arrangements and the like. Pair of lead wires in each desk , one lead forms an "active" antenna loop. That is, the transmitting antenna In some cases, an antenna loop excited by the transmitting circuit is formed, and the receiving antenna In this case, an antenna loop is formed to excite the receiving circuit. The other lead wire is "passive" loops, i.e. functions that are not excited or connected but are related only by mutual coupling. form a loop that interacts with the dynamic loop. The passive loop is properly passively excited. The combination of active and passive loops has a desirable flat will exhibit a linear amplitude response and a linear phase response. However, this beneficial result is may be obtained without substantially reducing the efficiency of an antenna constructed as such.

In addition, one of the leads of the pair, preferably the passive one, is connected when the tag is detected. 7-stem alarm device (e.g. warning light or buzzer) from the receiver circuit. ) can be supplied with an activation signal.

The system's receiver has improvements in the filtering and processing sections, and Improved method for detecting signals from tags or labels passing near the antenna It is equipped with steps. A linear phase (constant group delay) filter filters the received signal. used to more effectively maintain the improve the signal sent to the The processor has a “bisteresis” threshold detector will be provided. Following the conversion from analog format, this detector and processing routines adapted to alter the next processing of the sensed signal due to changes in the system. By improving the shape (width) of the final pulse sent to the Furthermore, there is a system that acts to maintain and distinguish between the different signals received by the unit. (Changes in the system will change the tabs or labels to send and receive antennas.) (based on changes and/or imperfections when provided to the provider).

These several improvements ensure different signatures of tags and labels passing nearby. can be identified and identified, improving system reliability, and Electronic article monitoring that can classify tags and labels by type and indicate their destination. This will lead to system provision. Regarding electronic article monitoring systems with these capabilities, Further details will appear in connection with the detailed description given below in conjunction with the accompanying drawings. Let's be fooled.

(Brief explanation of the drawing) FIG. 1 is a block diagram of a typical electronic article monitoring system.

Figures 2a and 2b show the transmitting and receiving portions of the electronic article surveillance system of Figure 1. 2 is a diagrammatic plan view of the improved antenna system used in conjunction with the section; FIG. .

Figure 3 is a schematic diagram of the antenna system shown in Figures 2a and 2b. It is a target line diagram.

Figure 4 shows the frequency and position of the antenna system as shown in Figures 2a and 2b. FIG. 3 is a graph showing phase response; FIG.

FIG. 5 shows an improved receiver for use in conjunction with the electronic article surveillance system of FIG. FIG.

FIG. 6 is a graph illustrating how a received signal is processed by the receiver of FIG. .

Figure 7 shows a digital It is a graph showing a method of converting into a display.

Figure 8 shows how the processor receives and distinguishes between various digital signals. 2 is a graph showing an operating method.

Figure 9 incorporates multiple monitoring and support devices in a single interaction environment. This is a schematic representation of the security system.

Like numbers indicate like elements in the several figures.

(Detailed description of preferred embodiments) Figure 1 is manufactured by Checkpoint Systems, Thorofare, New Chassis. Typical elements of electronic article surveillance systems of the type manufactured and available here include: 1 shows (in block diagram form) how it is generally configured.

The system 1 includes a tag 2, which can be attached to a variety of different tags according to known techniques. It can be attached to any item. For example, tag 2 is common to tags of this format. A form of "rigid" tag attached to an item using commonly provided connecting pins. It can be an expression. Alternatively, tag 2 can be placed under a hanging suitably tied to the item. It may also be in the form of a tag. Furthermore, tag 2 takes the form of a label adhered to the article. You can also do that. Any of the various types of tags and methods of attachment are covered by this general business. can be used to accomplish tasks.

The type of tag used or the method of attachment to the items with which it is combined is irrelevant. In addition, tag 2 has a resonant circuit (not shown) that can react to the applied field of electromagnetic energy. ) is included. A transmitting antenna 3 is provided, which is combined with A field corresponding to the operation of the transmitting circuit 4 can be generated.

Receiving electromagnetic energy from both the transmitting antenna 3 and the resonant circuit of the tag 2, the receiver A receiving antenna 5 is provided for generating a signal to be sent to the circuit 6. reception The device 6 is activated upon receiving this signal and transmits and receives signals in the vicinity of the transmitting and receiving antennas 3.5. The existence of tag 2 is checked, and if tag 2 is present, an alarm is given.

This generally improves the received signal by improving the signal picked up by the receiving antenna 5. This is achieved by adding an amplifier 7 which operates to Then amplified The transmitted signal is required to be used in conjunction with transmitting and receiving antennas 3.51. The high frequency (carrier wave) component of the signal detected by the electronic article surveillance system Recovering (or restoring) the active component (basic band) used to detect the presence of tag 2. is added to the detector 8, which operates to Next, the detector 8 separates the The separated baseband signal contains noise or other interfering components in the separated signal. a filter 9 that acts to further attenuate unwanted low-level waves and high-frequency signal components; added to. The filtered signal is a digital version of the analog signal received from the filter 9. operative to convert into a digital signal suitable for providing to processor 11 is sent to converter lO. Following this, the uke interprets the signal taken; The captured signal indicates the presence of tag 2 near the transmitting antenna 3 and receiving antenna 5. The task of checking whether this indicates an event to be detected is the process. This is done within the server 11.

As previously mentioned, conventional conventional configurations are designed to improve the resolution of the final system. The invention improves the transmission antenna 3 and the reception antenna in various ways. A signal indicating Tag 2 passing near Tena 5 and an event that should be properly detected. Its ability to distinguish between non-existent and other signals (noise, interference, etc.) has been improved and updated. Discrimination between different tags based on the difference in the signature of the resonant circuit included in the tag, 1111 The ability to perform accurately is acquired.

This improves the transmitting antenna 3 and the receiving antenna 5 and transfers the signal to the processor 11. The tsunami generator 9 and the transducer 10 operate to supply the This includes improvements to the routines (software) used in the process. These have been improved Further details regarding these matters are explained below.

The transmitter circuit 4 is substantially the same as the transmitter of a conventional general type of electronic article surveillance system. : Same *IR. However, if possible, the process of reducing distortion is carried out within the unit. be called.

Referring to Figures M2a and 2b, these illustrate the construction of an antenna embodying the present invention. Shows how it is made and installed.

FIG. 2a shows the transmitting antenna 3, and FIG. 2b the receiving antenna 5.

In each case a housing 7 is provided. This current preferred practice In the example, this housing 7 is made of hollow synthetic resin, inside which all the other parts are placed. In particular, the transmitter circuit 4 is located in the base portion 7a of Fig. (Fig. 1) is placed, and the receiver circuit 6 (Fig. 1) is placed on the base portion 7a of Fig. *2b. ) is placed.

Each housing 7 includes a pair of upright members 7b and U connected by cross members 7d and 7e. It has 7c. In each housing 7, the antenna loop 15 is connected to the base portion 7. Starting from a, on one side of the loop the upright member 7b and on the other side the upright member 7c. However, in the cross member 7d, this of the antenna loop 15 The two sides swap positions. In other words, the portion extending along the upright member 7b is the upright portion. The part that was extending along material 7c enters 7b. antenna loop 15 is completed within the crosspiece 7e.

This interchange of the upper and lower portions of each antenna loop 15 complies with FCC regulations. as it satisfies the need to reduce interference from external, remote sources of radio frequency energy. As appropriate, it causes far-field cancellation of the antenna pattern. It takes This technique of using one or more substitutions is known and is itself an essential aspect of the invention. It does not constitute an element.

However, according to the invention, the antenna loop 5 is preferably implemented with a biaxial cable. (Cables suitable for this purpose are Belden Wire & Co., P.O. Box 1980, Richmond, Indiana. - available from Cable Company under product number 9271). Kaka The cable has a pair of separate leads surrounded by a conductive shield. Equipped with an insulating sleeve. A conductor for grounding the shield is also provided and Spacers connect the leads to maintain uniform spacing of the elements within the insulating sleeve. Twisted together.

Using two separate, generally parallel wires to form the antenna loop 15 It is also possible. A pair of coaxial cables can be used. in any case It is also preferred that each lead wire be separated by uniform spacing from each other along its entire length. Yes. Additionally, twisting the paired lead wires uniformly along their length will avoid local defects. This is preferred because it reduces regularity.

When using a pair of shielded lead wires, as in the case of the twin-axial cable described above, In some cases, the leads inside the shield are used to help perform the basic function as an antenna element. For this reason, it is appropriate to provide a cut in this shield.

Such a break is shown at 9a in Figure 2a, and the leads inside the shield 9 are now exposed. are doing. To maintain the electrical connection of the shield 9, the upper and lower parts of the cut are electrically connected by conductors 9b and 9c. Although not shown, the second It is preferable to provide the same cut for the antenna 5 shown in Figure b.

In Figures 2a and 2b, this preferred biaxial cable comprises a cylindrical element 9 and a conductor. Represented somewhat schematically by electrical pairs 17a, 17b and 18a, 18b, this They are shown emerging from the open lower end of element 9. In particular, element 9 Represents the conductive shielding of a biaxial cable, with pairs of conductors 17a, 17b and 18a, 18 b shows the separate leads inside the cable.

In Figures 2a and 2b, these leads are respectively connected to the transmitter circuit 4. It can be seen emerging from inside the shielding 9 near the receiver circuit 6.

More specifically, conductors 17a and +7b are two separate leads inside the shield 9. The two ends of the same one are shown, and the conductors 18a and 18b are the shields. Both ends of the second of the two separate lead wires inside the ti9 are shown.

As shown in Figure 2a, the transmitter circuit 4 is connected to one lead and The exposed ends of the lines are indicated by numbers 17a, 17b in figure i2a. This send The circuitry for this lead constitutes an "active" load for this lead, inside the shield 16. The loop formed by the antenna constitutes the "active" loop of the transmitting antenna.

In Figure 2b I; connected to one lead is the receiver circuit 6. The exposed ends of this lead wire are similarly indicated by numbers 17a and 17b in Figure 2b. It's been done. Therefore, in Figure 2b, this is the "active" loop of the receiving antenna. This is a receiving circuit that forms a loop.

Now, the other lead wire inside each shield 9, that is, the end that comes out is shown in FIGS. 2a and 2. b The lead wires indicated by numbers 18a and 18b in each of the figures are described below. Bell. These other leads are connected to the associated active load (i.e. the transmitter circuit 4 or receiver circuit 4). signal circuit 6). The appearance portions 18a and 18b of these lead wires are , connected to a "passive" load 20 in each of FIGS. 2a and 2b, and The loop formed by each of these leads inside the shield 9 is connected to each antenna. Construct a "passive" loop.

Each of these passive loops is a reciprocal bond between two closely spaced leads. The stage is connected to the inner active loop of the same shield 9.

The impedance of passive load 20 is selected as follows. In other words, the passive load is When reflected through the mutual coupling to each active load, the total effect is without substantially reducing the antenna efficiency that would otherwise have been obtained. gives each antenna loop 15 a flatter amplitude response and a more linear phase response. The selection is made so that the

Due to the distributed characteristics of mutual coupling between the leads inside each shield 9, precise etc. It is difficult to form any circuit. etc. for the transmitter part of the system An outline of the circuit is shown in a dashed rectangle indicated by number 19 in FIG.

The second step in the method of carrying out the invention is shown in FIG. The use of lead wires makes the amplitude response of the antenna approximately the same as that shown at 21 in Figure 4. to an amplitude response approximately similar to that shown at 22, i.e., the operating frequency This results in a fairly uniform amplitude response throughout the band. Also, roughly similar to what was shown in 23. from a similar response to a relatively more linear response, denoted by t; A corresponding improvement in the phase response of N is also shown in FIG.

This flattening of the antenna's amplitude response and linearization of its phase response eliminate false alarms. Tag signals can be effectively detected over a wider frequency range without emitting alarms. It becomes possible to This means that the resonant circuit, which is a part of each tag 2, is connected between the tags. This is important because they have different trends in resonance frequency. For this reason, the usual method , the sweep frequency ( For example, 8.2MHz ± 800KHz) is required to be used in the system. . Even so, some tags are not compatible with the electronic article surveillance system in which they are used. Since it cannot meet the required tolerances, it will probably be rejected after its manufacture. wider By being able to effectively detect a wide range of frequencies, the electronic article surveillance system of the present invention Vision system 1 operates to detect a wider range of resonant tags, while manufacturing The number of tags rejected during the process can be significantly reduced.

The use of a twin-axial cable as the receiving antenna 5 gives the system another advantage. . When the presence of tag 2 is detected between transmitting antenna 3 and receiving antenna 5, appropriate The basic function of the receiver 6 is to issue a warning. For this purpose, Section 2b In the figure, a normal A warning light device is installed.

In order to turn on this warning light when necessary, this and the base 7ai of the housing 7 :li! It is necessary to provide a DC connection between the receiver 6 and the connected receiver 6.

For this purpose, passive leads (the exposed ends of which are shown in Figure 2b with numbers 18a and 1) are used. 8b) can be used. In particular, the direct current from receiver 6 The output is connected to this passive via a connection schematically shown by lead 26 in Figure 2b. It can be supplied to the lead wire. At the top of the loop formed by the biaxial cable , with a warning light device 25, as schematically shown by the connection lead wire 27 in FIG. connected to the same passive lead wire nearby. As a result, between the receiver 6 and the warning light 25, This eliminates the need for separate additional wiring. This eliminates the presence of such additional wiring. The potential negative impact on antenna performance associated with

The result is a more uniform response to signals received within the system's operating frequency range. It is a highly effective transmitting and receiving antenna with a wide range of functions. Exclude as out of specification. In addition to the effect of reducing the number of removed tags (thereby reducing waste), the present invention Another method that gives the improved receiver 6 a relatively "clean" (undistorted) signal 18 There are advantages. This is fully illustrated in Figure 5 and is handled as follows. Ru.

Referring to FIG. 6, the signal 28 received by the antenna 5 (FIG. 6a) is , modulates the operating frequency of the system (e.g., 8.2 MHz), and modulates the received The fundamental band signal (for example, For example, 20kHz). The operating frequency (8.2MHz) is the resonance frequency of tag 2. Preferably swept to measure variations in the road (approximately ±800 kHz per second). 82 times). When the tag 2 passes between the transmitting antenna 3 and the receiving antenna 5, this A small deflection 29 occurs in the envelope line of must be detected by the signal 6'. It should be noted that this runout is due to the phase and amplitude, but the magnitude is very small compared to the carrier signal (generally 1/1 1000 to 1/10000). Therefore, in relation to Figures 5 and 6, This signal can be isolated and identified using sophisticated detection techniques, as described below. must be used.

The received waveform is first amplified (amplifier 7) and then sent to a detector 8. child amplification, if desired, by prefiltering (at 30) and/or (at 31) Post-filtering may be included. The detector 8 essentially operates in the fundamental band (0-20kHz z) from its swept carrier (nominally swept at about 8-2 MHz). It operates like this. Therefore, the obtained waveform (Fig. 6b) is the separated fundamental band signal. The protrusion 33 substantially corresponds to No. 32 and is added to the transmitting antenna 3 and the receiving antenna 3. Deflection 29 (in amplitude and phase) caused by the presence of tag 2 between antenna 5 change). It should be noted that this signal was detected as fundamental band signal 32. the position and orientation of the tag 2 relative to the antenna 3.5, including variations in both the protrusion 33 and the antenna 3.5; This point tends to change depending on the situation. Before the obtained signal is sent to filter 9 (amplifier 34).

The filter 9 receives five carrier signals (8.2 MHz), including the signal received from the transmitter 4. ) other interference signals and noise outside the effective band that are received by the antenna 5. It operates to separate the detected signal 32 from other signals. this purpose Therefore, a low pass filter 35 to eliminate undesired low frequency components, and a subsequent A series of combinations of high pass filters 36 are used to remove unwanted high frequency components. It is preferable. .

These waveforms are detected and processed by system 1 in response to tag 2. It is a particular goal of the electronic article monitoring system of the present invention to maintain . Filtering inherently affects such a signal, not only in terms of its amplitude, but also in terms of its amplitude. It also tends to have negative effects by adding time-delay distortion to signals that are . The amplitude of the signal is preferably recovered in an amplifier 40 following the filter 9. Delicious. However, the initial waveform preservation deteriorates as a result of the time-delay distortions encountered. be done.

Referring to FIG. 6c, conventionally, such distortions are and the influence on the main signal 41 produced by the tag passing between the antenna and the receiving antenna. However, the effect on the distortion 42 created by the filtering stage must also be compensated for. There wasn't. According to the invention, the filter 9 is now configured to avoid the negative effects of time delay distortion. For this purpose, #l is constructed as a linear phase (constant group delay) filter. Various known Any linear phase filter configuration can be used for this purpose. The result is the transmitter The first signal created by circuit 4 #2 and separated from detector 8 (Fig. 6b) I This is the filtered signal 43 that closely matches the signal. As further explained below , this is a common thread that contributes to the various improvements provided by the present invention. This is an important advantage for subsequent processing. Further removes noise components within the operating fundamental band. It is preferable that a smoothing filter 44 is connected to the amplifier 40 in order to eliminate the noise.

Furthermore, the detection signal based on the presence of tag 2 has been increased from previously available systems. When indicating strength, such filtering allows the received signal to fall within a fairly low frequency band of the transmitter. are more effectively distinguished from other signals. See Figures 6e and 61 for explanation. Then, the receiver 6' receives both the signal 45 from the transmitter 4 and the signal 46 from the tag 2 ( signal and its harmonics). Shown in WB2 diagram As shown, the tag signal 46 (of the same general form) until it reaches the frequency band 47 ) would not be easily discernible from the transmitted signal 45. However, see Figure 6f. For example, the filtering described above causes the transmitted signal 45' to attenuate faster than the tag signal 46', causing the tag signal to The tag signal 46'' is transmitted as the transmission signal 4 within the frequency band 48 in which the tag signal 46' exhibits a large strength. It can be seen that it can be identified from 5°. This is the tag information available for further processing. 46'.

To explain with reference to FIG. 7, (response 51 indicating the detected tag and interference signal 7a) is applied to the transducer 10. The analog signal received from the filter 9 is supplied to the processor 11. converted into a digital signal suitable for This general form of preprocessor allows , the received analog signals provide sufficient resolution for interpretation by processor 11. is digitized to a 1-bit resolution (1 or 0) that has been found to be accurate. note Note that while this is currently preferred from the standpoint of its simplicity, if If so, it can be used in conjunction with a multi-bit processor for higher resolution conversion. It is also possible to

Referring to FIG. 7b, conventionally such a conversion is performed (for both rising and falling signals). 6C) applied analog signal (by generating a positive pulse relative to In order to perform the desired conversion (pulse formation) by the level fluctuation of the tag signal, The level above the selected threshold 55.56 centered on the selected level 57. This is accomplished using a threshold detector that operates to detect the signal. This is a filter From 9 onwards, the receiver generates a series of pulses with varying pulse widths, depending on the analog signal being taken. Generate positive pulses 58.59.60.61.

The width of these pulses obtained is determined by the characteristics detected between the transmit antenna 3 and the receiver 5. The "signature" of the specified tag 2 is defined. Other signals, especially electronic article surveillance systems Interference or murmuring or other pulses in the vicinity of the system may also occur. However, these additional This pulse has different characteristics (width) than the signature of tag 2 being searched for, so The stem's processor determines that a particular series of pulses corresponds to the tag 2 signature (pattern). It is possible to check whether the signal matches the signal (signal) or whether it is an interference signal.

As mentioned above, the wide band of signals that allow this determination to proceed is based on the previously described A transmitter and a receiver, and a combination that operates to better maintain the operating signal. It will be utilized by the transmitting antenna 3 and the receiving antenna 5 which are connected to each other. deer However, even with these improvements, the In addition to its primary function of distinguishing tag signatures from interfering signals, In order to be able to sufficiently discriminate different signals corresponding to different formats of tags, It is still difficult to distinguish between various pulses with sufficient characteristics of the processor 11. It was generally found to be inadequate.

The first reason for this is that the antenna passing between the transmitting antenna 3 and the receiving antenna 5 This arises from several considerations regarding Group 2. As with any tag In particular, when it comes to illegally removing items, Tag 2 is designed to ensure that the receiving antenna receives the maximum signal. The optimum position for the transmit antenna 3 and the receive antenna 5 (i.e. Generally, it is not placed parallel to the planes of the transmitting antenna 3 and the receiving antenna 5. nothing However, the tag is often placed at a different angle to the antenna. Will.

As a result, signals of different nature are often applied to the converter lO and the processor lO 1, the signals to be processed are a wide range of different signals. For example, see Figure 7c (for illustration purposes only). The relatively strong signal 65 was selected. Relatively wide pulses that cross threshold 55 quickly and return slowly to the selected threshold There is a tendency to make 66. However, the low intensity signal 67 It will arrive and return sooner, creating a much narrower pulse 68. This is the thing signals are found to complicate the situation and often undermine subsequent signal geography steps.

To distinguish between pulses that match the signature of the tag and pulses that correspond to interfering signals. A commonly used technique is that the pulses received t; The purpose is to check whether it has a duration (width) that falls within the range. This win A tag is established within the processor 11 to accommodate various possible tag configurations. It adapts not only to the different signals, but also to the wide spectrum of detected pulses corresponding to the interfering signal. It must be broadly defined. As a result, such systems identification between different types of tags (and their signatures) is not possible; 3. A narrow effective pulse (immediately It is not uncommon for these systems to fail to identify pulses (68). won. Enlarging the default window can help the system recognize large numbers of tags. Probably. However, this also identifies and accepts a large number of interfering signals as well as the presence of tags, It has the corresponding drawback of inducing a large number of false alarms. This generally reaches an optimum It demands that you hold back where you don't have it.

The present invention improves the overall detection process and tag signature and electronic article monitoring system. in order to more carefully distinguish the received signals from other signals that come within the operating range of the system. Various actions are taken within the transducer 10 and processor 11 for this purpose.

The first of these improvements forms part of the converter 10 and is in the manner in which the initial threshold comparison is performed. related. Specifically, a [hysteresis-type] threshold comparison was performed, and each transformed were selected to define (detect) the leading and trailing edges of the pulse (the two Using two different thresholds (generated by different comparator circuits 70.71) Ru. Referring to Figure 7d, two different threshold values 72, 73 can be appropriately selected. Therefore, the same initial signal 65.67 shown in FIG. 7C becomes a pulse 66.68. This would also produce pulses 74 and 75 that are fairly close in proportion to each other. the result , pulses 74.75 constitute a more accurate representation of the original signal. This is where it continues Not only is it applied to stronger signals, but also enabled by the converter 10. Applicable to weaker signals that extend widely over the area of the detectable signal be done.

The selection of two different threshold values 72,73 is based on the specific signature of tag 2 operating here. (characteristics) as well as the expected environment for the system. Therefore, Preferably, these levels are adjustable to accommodate different applications.

This can be set, if desired, at relative levels (i.e. upper and lower thresholds varying as a set). (threshold) as well as adjusting the difference between two selected thresholds. Wear. For special applications, the thresholds 72.73 can be adjusted such that one is positive and the other is negative. It is even possible to adjust the

Referring to FIG. 8, this improved signal has the following signature and interference source The processor 11 incorporates additional improvements for discriminating between. normal , the detected signal 80 (either a signature of the tag as shown or an interfering signal) Following detection of the leading edge 82 of the first pulse 81 resulting from the signal), the trailing edge of the pulse 83 is the predetermined pulse width set for the expected pulse width of the desired tag signature. Steps are taken to check whether the selected window 85 is within the window 85. If so If so, the next step is to examine the next pulse 90 in the series of pulses 80 detected. It will be destroyed.

Conventionally, this is preset (fixed) for the width of the second pulse 90 and that pulse. This was done by a similar comparison with the specified window.

However, with the present invention, this conventional technique is The variable window 91 is “redefined” (calculated and adjusted) according to the is replaced by an analysis of the second pulse 90 according to The calculated adjustments made are: Analysis of the first pulse 81 in the series of pulses 80 and the subsequent second pulse 90 It is made based on several assumptions made regarding the expected characteristics. If the second pulse 90 constitutes the signature of tag 2 (usually processor 11 The counter (given in software within) is not incremented as before. It will be done. However, this increment means that only two pulses 81.90 are resolved in succession. It should be noted that this decision is made later. generally requires a third pulse 95 of the sensed signal 80 to be analyzed before being detected. It is different from the traditional system.

As previously indicated, this membrane-based electronic article surveillance system Repeatedly sweep around the operating frequency, which causes tag 2 between antenna 3. is configured to generate a repetitive signal corresponding to the presence of. This is a This produces multiple signals of similar type that are detected by the sensor 11. Continuing on, the signal taps on the receiver. 2, or other signals (e.g. interference). In addition to the Steps are also taken to determine whether or not the reference is coincident in time with the reference. if If the identified signature is detected during a scheduled sweep of the system f; For example, the steps of incrementing the system counter are taken again. Ru. Otherwise, it is assumed that there was a false signal and the signal is ignored.

In conventional systems, this is limited to a selected number (e.g. 6 or 7 counts). This will continue until the counter reaches the counter, at which time it will be assumed that there is tag 2 and an alarm will be issued. It will be done. However, when Tag 2 passes through the electromagnetic field created by the system, the between the field (flux) and the resonant circuit of tag 2 passing through such field. Interrelationships often fluctuate.

This is detected in response to a continuous sweep of the transmitter circuit; the tag signal (mainly the strength ), which often results in effective recognition of the tag signature by Processor II. hinder. The improvements described in connection with the electronic article monitoring system of the present invention It acts to improve the reliability of the knowledge process.

Moreover, it is possible that the signature of the tag is not detected. Regarding processor 11 The reason for this is a series of further improvements.

In particular, if the system's scheduled Sweeping in progress! If this expected tag signature is not detected, set the counter to O. The traditional method was to reset it. This is to avoid false alarms and similar things. However, detection of tag 2 may fail. According to the present invention, this technology: Continuously sensed according to the periodic sweep of the transmitter! ;both signs and other events an up-down counter (in the processor 11) that operates to track the Replaced with For this purpose, when the tag signature is detected, then When a detected signature occurs following a scheduled sweep (default within the window), the counter is incremented. sweep signal Detected events that occur outside the window defined for are ignored.

If no tag signature is detected within the predetermined window, the counter - is decremented. This is because the counter is set to the aforementioned threshold (e.g. 5 count) or returns to 0 (no tag exists) This significantly reduces the impact of undetected signatures. various different counters It is noted that a set of options can be selected for use in this regard. For example, ment may cause one or more increases. Similarly, the decrement is l or more. The count established for the increment is can be the same as established for decrement (i.e. one-to-one ), or use a different count as desired for special applications. I can do it.

Referring again to FIG. 5, systems that provide these functions typically include It receives the main signal 100 from the i-value detector 70, 71, and also precedes the I-linear phase filter 9. from an external signal detector 101 (which provides logic levels for timing) A computer equipped with a processor 11 that receives control signals and attached to this specification Includes program list (appendix). If desired, the first pulse of the received signal can be resolved. Additional controls at 102 for changing the window used for analysis controllable (programmable) (the continuation pulse can be adjusted computationally as described above). window).

If desired, the processor II adjusts the sweep rate of the electronic article monitoring system l to can be controlled at 103 to change the sweep rate from 82Hz to t: It is noted that This is best shown in Figure 9 of the Electronic Article Surveillance System 1 Power Board. This allows tags to be sorted individually using different sweep speeds. do.

In practice, for the entire security system 105, the tag disabling device i09.110 and In addition to other supporting devices such as similar devices, multiple electronic article monitoring systems1 06.107.108 is commonly used.

In many cases, these #IF adults are placed relatively close to each other, which allows this Interference between these various devices may occur. Such interference may occur if each of the various units Occurs by operating at one fundamental frequency. Small differences in these operating frequencies , or small differences (due to design tolerances and the like) in these synchronizations Beat patterns can sometimes result in false alarms and other false signals.

Traditionally, these synchronize the several uni-nodes used into one main unit. (for example, installing devices 106.107 and disabling devices 109.110 [108] synchronization) between the various units used. He avoided interference. However, this requires a lot of wires to connect several units. It complicates the installation of such systems, and such interconnecting wires (which themselves are subject to interference (acting as an antenna that generates signals) often causes unacceptable interference. It is possible to live. In either case, during the initial installation of this membrane-type security system, In order to reduce as much as possible the aforementioned problems, the various components of this system have been Careful adjustment (y4) is necessary. Sometimes it is necessary to maintain this careful balance. It is necessary to readjust various components of the system in order to maintain

The present invention allows each of the various components that make up the embedded system to be Operates at sweeping speeds, thereby avoiding possible interference between the respective components This eliminates the need for the special measurements mentioned above.

For example, devices 106, 107, 108 can be operated at three different sweep speeds and 109, 110 can be operated at fourth and fifth sweep speeds (no as long as the activation speed of the activation device is different from the activation speed of the associated electronic article monitoring system; There is no need to run this at different speeds).

This improvement in system operation due to the programmability of the processor 11 is accomplished in a simple manner tailored to the specific application desired.

The different sweep speeds used are The selected sweep speed allows the system to discriminate between available sweep speeds. The selected sweep rate is approximately 70 H2 or higher to separate by at least 3 Hz and It is considered important to maintain the frequency below approximately 90 Hz, but the It should be noted that it is also possible to

These above-mentioned adjustments can be made, if desired, by pre-established programming of the processor 11. by selection by a ram or by a switch depending on the specific application required. can be incorporated into the system. This is the basic sweep rate for the system selection of window parameters for tag signature detection; Including both.

Therefore, various improvements have been made to significantly reduce distortions in the system and to to better preserve the fundamental signals generated and also to interpret the obtained signals more effectively. It will be understood that the invention may be used in combination in order to This includes distortion In order to reduce the improved configuration of tena 5, improved configuration of filter 90 and converter IO, and Special features of the present invention include improved processing routines performed within Prosensor 11. Improvements are also included. The result is that the system separates the tag's signal from other interfering signals. Be sensitive enough to not only improve identification but also discriminate between different tags. Is Rukoto.

Such improved identification is not achievable with traditional electronic article surveillance systems. gave improvements to abilities. For example, tag grouping by tag signature (characteristic) It allows precise identification between different tag formats, which allows group classification. child This can be used to achieve more error-free results or with electronic article monitoring systems I Electronic article surveillance systems are used to differentiate between different tag formats that are used together. It is well suited for use with System 1. This is also to avoid interference with adjacent components. to vary the sweep speed used in conjunction with the operation of the electronic article monitoring system. It can also be used for food. Additionally, these features are dependent on the processor as mentioned above. By adjusting (programming) the parameters used in can be easily changed.

Details of the parts, materials and illustrations herein described and illustrated to provide a detailed description of the invention. Various changes in arrangement can be made by those skilled in the art to understand the invention as set forth in the claims below. It will be understood that anything may be done without departing from the principles and scope of the invention.

T Lua T Receiver-f) 14 Talop O Seyser 63 (A/B) 01/637 ( A/B) OIVOC program (6MHz resonator) (Fixed sweep speed selection) (Patesonic smoothing filter) ψThreat 1111 Meeting ＊＊＊＊Meeting Sokei 豐 Meeting Meeting Fees - VEFLl, 2A Suga Meeting Meeting 1111th meeting 1111th meeting 1111th meeting 1111th meeting 1111th meeting "POR DEFINmONS meeting" Meeting expenses ψ threat ψ◆ meeting ψ 會彎－■■c■■■E－ MICROIs SEr UP IN MODE 7 (SINGLE CHI P)0RTI PI3 PI3 PIS PI3 PI3 PI3 Pll PloMSBPgmSelLSB AImTime Alm5r c (+) (-) Jla Jlbinininininin, in・sw pselin POR 2 P27 P26 P25 P24 P23 P22 P 21 P2ON / U VideoEn 10th (Video) --ModeSet- (M-in　　　in　　　　　　in-0RT4 P47 P46 P45 P44 P43 P42 P41 P40TP5 TP4 P, S, PSEn Extl nh Aim A1ml1g-oLTIoLllin-in i n Out table with oul-discount plddrequOOh p2d+jrequ(Hh p1dataequ02h p2dalaequQ3h p4drjrequ05h p46maequ07h stacktopeqUcmh romcquanequo+oooh ramstart equi 40h ramstop equi 0Ffh ρStmaX equ 45 electric csreq08h oar equi 0bh beep+ime equU ocooohicr equ Odh 1imer eqU 09h tworrset equ 1200 onesec equ 22: one see, timerf’mec e qu 112: l1ve sec, mmermaskon equ 02h swp78 equi 19230 swp82 equi 18290 swp86 equi 17440 swp90 equi 16670 swpmin78 equi 19480swpmin82 equi + E15 20swpmin86 equi 17650swpmin90 equi 168 50swpmax78 equ 18990swpmax82 equ 180 70swpmax86equ 17240swpmax90equ 164 80swpadi78 equi 20 swpadj82 equi O swpadj86 equ -20 swpadi90 equ -35 The 6301 is configured mode 75t atus as follows: 1, Internal RAM from 40h to FFh2, Internal ROM from FOOO h to FFFFh3, NMI 1ie (j to ground4, IR Qlinemuexpudenobeatnotedetectionckt-5,0u tput (P4 used fot Alarm Level 16. nmer 1npt++ (P2O) used for +thresh ored - thresh 1nput7, P42 is 0trlp+J used f or 5ona+en and lamp driver8, P10/P11 (Jssetea sweep rate parame+ersstaIu s ds 1 signflg ds 1 tleads2 tfaltds2 +ends2 Iemp ds 2 tlimas ds 4 pcnIds 1 vflag ds 1 almenllg ds 1 pstimflgdsl ptimer ds 1 a1mcn electric rds1 window ds2 window2ds2 jpcnl ds 1 Time95ds2 almflg ds 1 +mark ds 2 taclcn(ds 1 sri=hf1g ds 1 vent ds 1 a+imer ds 1 a+jmf1g ds 1 rtclk dS l Ir1pCnt ds 1 1dellim dS 4 electric dropds2 +bufl ds 2 2bn1l1 ds 1 -nhf1gds1 sv/ptime dS 2 swpITIIndS2 swpmax ds 2 bastrmrt tis 4 Initialization procedure org rom Yu Dong reset Idaa #00000000b :1nit UQ port l5taa ptadr Iclaa #ooooOooObSlaa pldata ldaa #0O001000b :ini ilo port 2s +aa p2ddr Idaa #0O001000b;disablecompostlevi de.

5laa p2data ldaa #1100 (Hlob:1ntli10pOrt4Staa p4ddr Idaa 100O00000b Staa p4da+a lds #5faCklOp ;1nil IOp of Stac kramchk Idx #ramstarl ;wrhe/rea dramldaa #Oaah ram+p1staa O,X cmpa O, x bne ramerror ― cpx #rams+op+1 bne ramlpl Sophistry #[a 鴫鴴 1daa #5Sh ramlp2 Amount aa O, x crrIpaO,x bne ramerror CρX #ramsIOp+1 bne ramlp2 bra ramok ramerrorrldaa #01h ;setbttoor status staa 　　　　5 status bra rorrchk ramok clr 5talus; racejbi.

romchk Idx #romstart; comparerom chksumka romlp adda Qxnx bne romIp Gorge Kl romok Idaa #02h ;set b stroke 1 ofstatus oraa 5 tatus bra romexit romok Idaa #0fdh ;clear bi' 11andaSta+LIS romex II 5iaa 5tatusiochkldaap2d ata;getlevelsonpOt12anda #OOO0111 1bcmpa #0O001111b; normal reset 1e velsbne　　　1oerror ldaa p4dala :(lel 00n41evelsan cla #1100l1000110b IDCKK)OOOObbn e　　　　1oerror bra 1ook ioelTOr 1daa 5tatus ;+, +pdat e 5tatus 咋eoraa #04h ;set ba 2ols+5usbra 1oexit io　ok　　Idaa　　　5tatus　　　　;clear ba 2aroja #CjTbh ioeXit 5laa 5tatusbeepcode Ida a 5 tatus; get status ccxieanda #07h beq notau company brta#01h;+estrambt+bns rambeep bita #02h ;test nom bitbne rombeep bhp, zQ4h ; test Vo bhbne 1o beep noIautl Idab 11bra beep rambeep Idab 12bra beep rombeep 1dab 13bra beep iobeep Idab #4bra typ beep　　　Idaa　　p4data　　　;alarms　ono raa #06h Slaa p4dala lclaa #2 bsr bdelay ldaa p4clata ;alarm offanda # 0f9h Guo p4da+8 1claa #3 by bdelay ecb bne　　　beep bra mexl bdelay Idx #0cO00hblp1 dex bne blpl eCa bne bdelay rnl! y1 1daa12 :+nI'IIcjet Coun terstaa pent clr pstimflg dr Vent dr vflag dr almenllg clr srchflg C1r ta9cnt clr almflg car ps+imer C1r almcnlr dr rtclk clratim mouth 9 elr atimer dr bniflg air inhflg ldd! imer ;ini+valid reply tim ersStd +end Sld tmark Reading target type selector switch option　Idaa　pldaza　;read option iumperanda #0cOh bne 1I Idx #t11imis; 9et 11 pulse limasl dd O, x std baslimit ldel　　　2. x sld baslim +2 1 daa #5 staa tnpcnt bra flas+ iI Cmpa #40hbne 12 Idx lI31Imhs :ger tl pulse 11m1 g1dd O, x sad　　　　　basltmitIdd　　　　　2. x sld baslimi'I+21daa #5 slaa tripcn+ bra city i2 cmpa #80hbne j3 1dx #Ll) Iimls; 9et 11 pulse l1m 1zsldd O, x Sld baslimi + anger Cj 2+X 5Id baslimiI+2Iclaa #5 *aatripcnl bra rtast p Idx #t41mits ;get 11 pull se　11m1tsIdd　　　　　O, x s+dbaslimi+ ki6 2. X 5td　　　　　Overnight at hasIimit+2 a#5 staa tripcnz brI11as! rlas+ 1dbaslimrlHinitaltimewindows std tdetlim ldd basIimit+2std tdetli m+2Idx #swptbl ; int+ Swe eratewindowsIcld O, x S1d swprom61dat) IrB bx Idd O,X 5ad swpmin ldab lie bx Idd O, to Sld SWpmaX Idaa Ic5r :enable ocLiedg (- ) anda #11H1101boraa #0OO1100 0bStaa IC3r +tiaa p2dala :enable composie video.

anda #0f7h Staa p2dala li main ldx #swp+bl ;get, HP osLIionandldabpldala:CONVenlosweepra IeClalaandb #03h slb bx ldd O, x; gel sweep periodmd swp+ime ldab #8; gelmin, sweeptimebx ldd Q, x Std SWpmin ldab #8: gel max, sweep Limebx ldd O,X S’ld　　　SWpmax Selected sweep speed window timing adjustment Ida6 118;mak e sweep / window adjusementsbx ldd O, x add baslim stroke std tlimis Idd O, x add baslimi+2md+11m1tS+2 Check external flags and sensors Idaa p4data: checkex+emal bud nhtbit baa #08h Sekiq no-1nh +daa　　　　#o+fh　　　　：se+　eXIernal 1n hibh flags+aa inhflg Idaa p2da! a ; disable video input a 5 oah Staa p2dala bra a+armen no-inh clr inhflg: clear ex+er nal tnhibit flagIdaa p2data ;ena ble video 1nputanda llCf7h Staa p2clala alarm! dab #0ffh ; setalarmenab leflagstab a1men! Ig Idaa p4data btla　　　#0O010000b　;+es+peopleansore nablebne primsIal : 5fanSOrena bleddr pstimllg bra valchk pums+a+　IsI　　ps+imf1g　　;peoplesens or+imerrunning? Sekiq psense Idaa #ps+max ;check for peo ple 5 sensor + imeoutαηpa ptimer 1) lli valchk pL inh cl "almenllgclr pslimng bra valchk psense bita #00100000b ;5enso racl~e? bne pL-inh cIr　　　　　ptimer　　　　　：5tarl　person 5ensor timerklaa #0ffh s'Iaa ps'Iimf1g t0+--Membership--Membership--Meeting--Meeting--Meeting--Meeting Do you enjoy Cao Feng's visit to Cao Feng? Addiction quality ψ meeting fee φ and e■■■■■■ Checking various target windows, etc. and time sorting Meeting 1111 Fees 11 Meeting fees Meeting tψ豐φ豐 ◆ The meeting 1 valchk tsI vrlag ;validreply? 1 )eq +imQCtlk clr vflag ldd tmark :5aVe 1ast valid time s16 Dego kjd　　　　　1end　　　　　　　　; mesad tmark tsI srchllg :aquire mode (clear ) Sekiq pu+5eI Idd　　　　　tmark　　　　　　　　;repQinwindow? 5ubd Iime95 bmi early :replytoo earthyvnext 1 5 ubd swpminadd swpmax 1) pl failsrch ;reply too +ateld d tmark :update next windowaddd swpmax std time95 Alarm threshold counter increase/decrease adjustment inc I29Cnl Idaa　　　　　　tagcnt　　　　　　　;alarm condi tion? +s+a　　　　　　　　　：valid tag three hold den.

bpl　　　thresh cxr　　　tagcnt　　　:zero　negative　Cou ntimp noalarm τhreshcmpa#10:l1m1tcount+erbit CnteSt Idaa #10 staa tagcnt [:[1testIdaatagcru:IeStfOrthreSll, CO Unlcmpa tripcnl blo noalarm Iclaa #0flh ;se+alarm flags taa almflg dr vcr++ bra vexh +imechkIddtmark; checkfor+imeouτadcld swpmin sur electric imer bmi failsrchbra vexil railsrch C1ra :reSQ+fla gss+aa almflg dec t, agcnj -a rne’a s+aa　　　srchflg　　　　;1ose　aquisaions taa tagcnt fnext ldd tmark ;update tim e 5lotsaddd swptime Std　　　　tmark add swpmax 5Id time95 0raa　　　　＃α廿〕 s+aa p4data nex+ Imp Main internal cloak routine ) 111 + ☆ 111 + 1 - 111 + 111 + 1 - 111 + 111 + 1 - 111 + 111 + 1 - 111 + 111 + 1 - Fung - Cost Fung! Book meeting - 1 Meeting meeting - Ken meeting expenses Meeting meeting 1 Telephone bottle■■■^Enjoyment bag meeting ψ− timeclk 1daa tcsr :clear o C Hyaku LagLDD OCR: RESEL 1nlerrL+pl zulagstd oar inc nclk inc　　　　　ρslimer dec a+Imar Composite video processing routines tde!　　Idaa　　pldala　　　：de+ermine+ /-thresholdanda #OOO01100bcmpa#Oc h: dingalseleveldefect addition q　　　　ttau old bi'Ia #000QO100b , + threshold? b ne tminusj air signllg bra window (minusf Idaa 1Iotjhstaa signf lg window Ic1d ier :get 111. twlstd tlead add #twoffse+ :campu+e end tim e　wjndowsld　　　1drOp ldx ; delta time tablen slope 1daa tcsr ;arm fallin g edge (+)oraa #02h SiaaIC3r ldaa　　　　icr　　　　;clear id flagicllp +Idaa 1csr:WaFI for idlag bita #80h bna Re! mesav 1(ld tdrop subcl timer bmi tlault? bra 1dlp t tfauh 1 7mp Iexhhimesav 1daa t csr　　　　;aryy+Ieadingedge(-)ancla　　　 Iαdh staa tcsr Idd　　　icr　　　　　;get tf(n)std　　　t lall subd + Iead: dei(n) = tl(n) - tl (n) std jemp subd O, x +deh > delt (min) bmi 　　　texit lclab #2 ;update Iimtt addr, painterbx ldcl　　　　Iemp　　　　　;deft　　　deft(max)sub d O, x bpl texIt Adaptive calculation of next pulse ldd Iemp ;updale pulse 11m1tsa ddd #180 ssd O, x idx #tdetlim ldd temp add #2 Std O, x deCent beq valid icrlp2Idaatcsr;wai+foricflag(-1bita 　　　　180h bnesrgncr* 1cld Idrop; check for window 0 VelflOWsubcj　　　timer bmi jexi bra 1cllp2 Video sign replacement check signchk　Idaa　　pldala　　　　;ge++hres holdsignanda 11α)001100t)cmpa #Qch　　　　　　;check for 1alse 1levels related Ie is bita #0OOOCHOOb ;+ threshold? bne 　　　　tminus2 tst signflg :check tar sign c hange sekiq leX pa clr　　　　signllg bra 1neX+ lm1nUS21sI signllg knee 1hreStlO 1dbne IeXit com signllg +nex+ +adicr ;get t(n)d tlead bra n5lope valid 1claa #0flh :set valid tep7 flagstaa a9 ldd Idrop ; upcla+e valid time da d tend Idaa p4da+a ;validreptyin d, ont, p, 5anda #10111111boraa # 0100QOOObs133 p4c+a+a Idab #25 :set valid pulse width h (Sous) + pdly decb bne tpdly ancla #10111111bstaa p4data lcjaa tcsr; dear electric ag ring ing edgeIdaa 1cr teXit 1daa tcsr;realmnegat ive 5lopeancia #0Tdh staa tcsr ldaa icr ; clear icf flagIdaa ＃2　　　　　;restorecounterporterst aa pent ldd trmffs ;restore tl pulse l irnitsstdtdatlim Icjd　　　tlimtLs+2std　　　tdetlim+ 2ti External signal adaptation prohibition function bni Isl bniflg :already in th Is it routine? bna xrestore ;r estore 1ndex register on 5lackIdaa #0ffh ;set bni acIiVe flagstaa 　　　　bntflgIdaa　　　p2data　　;1nhiba　v Ideo for a timeoraa #08h Staa p2 (jala Idx #320; clelay Time w (20+25 ”　N)　us.

bnidly cli ex bne bnidly ei tS′1inhf1g :check external 1nhibix flagbne　　　　bnexz anda 1lcJr7h ;enable video line5 laa p2data bnexl 1daa +csr ;cle ar possible icrflagIdaa icr ;when video is enabledclr bnffl g Mountain xreSIore +Sx ;Iormpoir++er +ostackedxregldd 1500 :reSIor e original delay value initial pulse window table Hlirrmsdw320,5(KOKlyindowIimeS(0,Sus/ cnl) L21imils dw 360,500+311m1+s dw 400,500t41mils clw 42 0.500 fee 11 fees Il helmet meeting--I11 snow- meeting bag! Bag meeting - Bag ψ 豐 meeting 豐豐豐豐 Meeting - Fees - Fees - Fees - Fees - Fees - Fees - Fees - Fees - Fees ■■■■ Sweep speed selection parameter table swp+bl dw swp78dw swp90 dw swp86 dw swp82 dw swpmin78 dw swpmin90 dw swpmin86 dw swpmin82 dw swpmax78 dw swpmax90 dw swpmax86 chv swpmax82 dw swpadi78 dw swpadi90 dw swpadi86 dw swpadi82 orgOflOOh; versioni, d, stringdb ALPHARECEIVERVER,1,2AiO/10/88'org 　Offeeeh dw reset 9os+processor rec INer’f traporg (Xff4h dw+imeclk:coarserealtimeclkusing;oar 　overflow org 0ff16h dW　　　　　Idet　　　　　;Il’1reStlllO1d　dete ctor (timer) 1nlerrtlplor9 0ff18h :t)eaInQIe defection interruptd w bni org Offleh dw　　　　　resel;5tart　Of reset 5ection end reset FIG, 6e FIG.9 international search report

Claims (1)

[Claims] 1. A transmitter that feeds a signal into a transmitting antenna to form an electromagnetic field and should be protected. produced by a resonant circuit forming part of the first tag means associated with the article; a receiver having means for receiving a signal including a signal assigned to the tag and identifying the signal of the tag; a receiving antenna that provides the received signal to the device, and a resonant circuit of the first tag means. a resonant circuit of the second tag means different from the first tag means; An electronic article surveillance system equipped with means for identifying the tag with the signal generated by the tag. visual system. 2. The receiver converts the tag's signal to other signals received by the receiver. Claim 1, further comprising a filter separating the filter from the filter, the filter being a linear phase filter. system described in. 3. The signal of the tag is an analog signal, and the receiver converts the analog signal into a digital signal. means for converting into a digital signal, the converting means being responsive to two different threshold levels. 2. A system as claimed in claim 1, which operates by: 4. One of the two different threshold levels defines the leading edge of the digital pulse. the other of the two threshold levels defines the trailing edge of the digital pulse. 4. A system according to claim 3, which operates to. 5. The tag signal is in the form of a series of pulses, and the receiver synchronizes the tag signal. processor means for determining whether the first pulse of the series of pulses is means for testing whether the duration falls within a selected window; A window in which the second pulse of the series of pulses varies in response to the duration of the first pulse. and means for testing whether the claim has a duration that falls within the window. The system according to paragraph 1. 6. The selected window is adjustable according to the tag means to be detected. A system according to claim 5. 7. The receiver counts signals of tags identified by the processor means. a counter that detects the tag's signal within a predetermined time range; Increment the value for each tag identified in the tag, and when the tag's signal is As stated in claim 5, the value is decremented when the value is not identified within the range between system. 8. The transmitter sends a main signal that is periodically swept around the main signal at a specified speed. 2. The system of claim 1, wherein the system generates a signal, the speed of which is adjustable. 9. The transmitter that feeds the signal to the transmitting antenna to form the electromagnetic field and the made by a resonant circuit forming part of the tag means associated with the article a receiver having means for receiving a signal including the signal and identifying the signal of the tag; and a receiving antenna that provides the received signal, and the signal of the tag is an analog signal. Yes, the received signal comprises means for converting the analog signal into a digital signal, and the receiving signal comprises means for converting the analog signal into a digital signal, The means is an electronic article monitoring system that operates in response to two different threshold levels. 10. one of said two different threshold levels defining a leading edge of the digital signal; the other of the two threshold levels is configured to define the trailing edge of the digital signal. 10. The system of claim 9 which operates. 11. A transmitter that feeds a signal into a transmitting antenna to form an electromagnetic field and any protection created by a resonant circuit that releases a portion of the tag means associated with the article a receiver having means for receiving a signal including a signal of the tag and identifying the signal of the tag; The tag's signal is transmitted through a series of pulses. the receiver comprises a processor for identifying the signal of the tag; step is the duration during which the first pulse of the series of pulses falls within the selected window. means for testing whether a second pulse of the series of pulses has a second pulse of the first pulse; whether it has a duration that falls within a window that changes in response to the duration of the pulse An electronic goods monitoring system comprising means for verifying the 12. The selected window is adjustable according to the tag means to be detected. 12. The system according to claim 11. 13. The receiver counts the signals of the tags identified by the processor means. a counter for detecting the tag's signal over a predetermined time range; The value is incremented when the tag is identified within the predetermined range. Claim 11: Decrementing the value when the value is not identified within the time range. system described in. 14. A transmitter that feeds a signal into a transmitting antenna to form an electromagnetic field and any protection created by a resonant circuit forming part of the tag means associated with the article a receiver having means for receiving a signal including a signal of the tag and identifying the signal of the tag; a receiving antenna for providing the received signal, and the transmitter is configured to generates a main signal that is periodically swept around the main signal, and the speed is adjustable. An electronic article monitoring system.