DE2035356A1 - Method and device for determining the condition and identity of objects - Google Patents

Description

M 2864

^% PATENT LAWYERS

Dr .. | na. HA-. ^: S RUSCHKl Dipl.-lnjj. H 1. &Quot; 2AGULAe,

BEa; : t-j 33 Augusta-Viktorla-Slral · f «

Minnesota Mining and Manufacturing Company, Saint, Paul Minnesota 55101 (Y.8t.v, A.)

Method and device for determining the condition and identity of objects

The invention relates generally to devices for determining an object using magnetic alternating fields and in particular to devices in which the object to be determined does not need to come into contact with the devices themselves ¹¹ , and in a certain area, an "interrogation zone", a magnetic contact field is generated through which the object must wander. In this case, either the identity or the state of the object is determined by the magnetic addressing of the eesponder.

In French Patent No. 763,681, issued to Perre Arthur Picard, a device is disclosed in which dynamically

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see magnetic phenomena to determine presence an object such as a book carried through the door of a library. The establishment according to Picard is based on the discovery that when a sinusoidal alternating magnetic field acts on a piece of metal, a voltage is induced which is characteristic of the metal composition and which is balanced in two Coils in the vicinity of the generated magnetic field is induced, line analysis of this characteristic stress hence a classification of the metal in the generated magnetic field. A Buoh can therefore be determined »at to which a piece of metal of a special class is attached.

Picard called a class of metals "those for." a magnetic saturation a strong magnetic field must be generated · In the French patent specification mentioned, it is stated that · the sound induces a voltage to a metal from the class mentioned, except for a basic component a certain · number contains harmonic components · Haoh of the description produced such a metal »namely iron« a voltage »which has a third harmonic · and a small proportion of the fifth harmonic contains

Picard also teaches »that highly permeable metals» e.g. those metals »which saturate in a weak magnetic field» a Induce voltage »which, in contrast to the voltage induced by iron, contains harmonics of higher order. Picard mentions Permalloy as a highly permeable metal and states »that the τοη Permalloy induced characteristic stress as components harmonics of the ninth and eleventh order In contrast to metals such as copper, Elsen or aluminum »dl · practically do not produce any harmonics of such a high order ·

Vaeh der Lehr · τοη Picard only determines the composition of a metal the order of the harmonics »which are present in the characteristic tension. Picard also teaches “that the size of the metal piece and its outer shape

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Affect the amplitudes of the harmonics proportionally. Accordingly the ratio of the two individual harmonics would be the same for a particular metal regardless of size and the shape of the metal piece Picard also teaches that Ratio at least between selected components for different metals is characteristically different. Picard however, indicates that the size of the piece of metal to be used as a responder is important, not just for determining the order of the harmonic present, but rather for the generation of a signal that is sufficient for the determination is strong.

The teaching of Picard therefore says that metals with a high Permeability and in particular Permalloy can be distinguished from other classes of magnetizable metals by that there are harmonics of the ninth and eleventh order, and by the ratio of some more characteristic harmonics Components to each other «

So Picard believed that Permalloy was a suitable material for inserting a special Merall marker into Books in a library was because normally hardly anyone would carry a metal sheet with them »

There are several devices in the Picard patent for generating an electromagnetic field disclosed. One of these devices has an S-shaped coil. That from The field generated by such a coil has only one direction at one point, while the entire number of directions is only a part of all possible directions. Another The device is equipped with two coils, which are excited at the same time, but in which there is no phase equality, so that a! eld is created which is referred to as a "rotating" field will. Such a Jew points at different times in each case a different direction, which different directions, however, always only form part of all possible directions. Furthermore, the size of such a rotating field is small compared to the size of the coil. Of course, by generating of a field with a great intensity as opposed to one

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"Minimum intensity to reduce the unreliability, which is a consequence of the fact that in some directions There is no field · Such a strong field would have more vector components with sufficient intensity than a field with a minimum intensity. (Sin PeId with a minimum intensity is a field that supplies a responder with sufficient energy when the responder is for the "greatest sensitivity." oriented ") Here the directions are increased, which in the field are possible. With an increase in intensity However, de · feldes will generally cover the costs of the field-generating means and increases the risk that the use of other facilities is hindered or disrupted.

With the devices of the type mentioned above, it can only be achieved with difficulty that every responder receives sufficient energy when entering an interrogation. Although "energy" is a function of time and intensity, for the sake of simplicity, the expression "energy ^{11" is} intended to mean only its intensity hereinafter. The energy received by a responder at one point in a zone depends on both the field intensity At this point as well as the orientation of the responder with respect to the direction of the field at this point, the plane, the axis or the length of a responder are suitably used for the definition of the orientation of a responder. Known responders indicate a flat · Receiving coil, an axial electric dipole or a piece usually in the form of "an elongated strip" in isotropic magnetizable material, which has at least one long dimension · The orientation of such geometric features (plane, axis, length) in relation to the direction The field ·· generally determines the proportion of the energy de · field ·· at this point, which is determined by the Resp onder is received. The expression "sighting or intensity of the field" used in the present description is intended to mean "1" ti! * "*" Or the intensity of the field at one point, «Ad di ··· position is usually di» j «nig« lt «lle where there is eioh a leaponder, with a © * Btmpwimr, Ut mwt · ί» aolta * · f «4« «« rleaA ·· feature Attf * «Iei _f -tomttht« in ·

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Orientation where the responder receives most of the energy. Any other orientation will receive a small amount of energy. The orientation at which the greatest amount of energy is received is the "orientation of greatest sensitivity". In general, the orientation with the greatest sensitivity of a receiving coil or other planar receiving means is that orientation in which the direction of the field is perpendicular to the plane of the coil or of the receiving means, and in the case of an axial electric dipole this is the orientation in which the The direction of the leide runs parallel to the axis of the dipole, while in the case of a magnetizable metal piece the orientation of the metal piece is that orientation in which the direction of the ieldes runs parallel to the longest dimension of the metal piece (straight). The terms "orientation or direction of a responder ^M " used hereafter are intended to mean the direction of the geometrical feature of the responder which is used to "define the orientation for the greatest sensitivity"

Of course, in some cases the payment can be made of a responder in a zone may be random, or the direction changes when the responder is moved through the zone. This applies to those cases in which theft is prevented should be. In most areas of use, a responder can take any possible direction, which can also constantly change. For example, there is a responder on an item being carried on a conveyor belt, it is very likely that a responder will only be some of them all possible directions and this does not change the zone while running. These considerations and those involved in setting up Desired Reliability are important factors in determining the requirements for the field, i.e. determining whether a field component along each direction at each point of the zone, along each direction at some points in the zone or along only certain directions in one or in most of them Places in the zone must be provided. With the expression "f« ld component · is of course a · tector · meant, whose intensity provides the receptor with * sufficient "eggs.

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■ The field of dae zn Vice end requirements depend also the external fora dea Responders from "yon This Auforderungen are of course less strict for a" multidimensional "responder ale for a" one-dimensional "responders. Her multidimensional responders have two or more geometric features, each of which has a different direction. “One-dimensional responders are flat coils, foils and electric Dipol®. One-dimensional responders are generally preferable to multi-dimensional responders because of their cost and potential for damage. With some. In areas of application, other considerations lead the one-dimensional responder to want "!" If not absolutely necessary. For example, the ability to hide the device as protection against theft is a very desirable feature.

One embodiment of the invention provides a very reliable one Attachment «to intdtoken. of an object through spontaneous generation of fields in several directions. " The peak intensities of the field «· are thrown in such a way, toe · a si * Activate a ·· leepond # re Sufficient field co-workers in almost every direction - generated will. Di · f elder count as one. loXge tob impulses replace " with each impulse in the sequence having a different direction «. The invention uses the electrical attitude, with the very short pulses and as large a number as possible During the holiday, a responder would be sucked in led by a Üker ^ »oliBBgmBone.

The irfindmBg eieht furthermore eia koataktloiee ferfaiiren for detecting the presence, identity or dee Zustandus a Segenstandts in finer überwacliiimgezoiie before "z # B" at the output of a library, laughing this retracts, is every to be discovered Oegenntand a responder angek "oiit _f the least of an open strip of a ferrönagaetic material with a total magnetic saturation moment of at least 0.1 electromagnetic units or "IPol-centimeter ^1. -The open strip is chosen so that cSreesen magnetization

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at an orientation for the highest sensitivity with respect to to a sinusoidally changing 60 Hz test magnetic field alt a predetermined peak intensity τοη less than 20 Oe is reversed each time the test field is changed.

Strictly speaking, this is a complete reversal of magnetism a polarity opposite to the other saturation state is not required. The term "inversion or magnetization reversal" is intended to mean a periodic change in the magnetization of at least 0.2 electromagnetic units per cm for one Mean change of the acting field.

In the surveillance zone there is an electromagnetic. Generated alternating field, which has at least said predetermined peak intensity and is substantially free of frequency components having a predetermined frequency of at least

Continuation! Page 7

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Exceed 1,000 Hs. If an object provided with an open strip is introduced into the generated field, and are orientates the open stripe and a vector component of the generated field, the magnetization of the open stripe end is reversed with each change of field Magnetic field generated. Funding is provided with which in the proximity of the detection zone a whole band of frequency components of the magnetic flux can be monitored. The lower one The cutoff or cutoff frequency of this band is higher than that predetermined frequency, while the bandwidth is at least 600 Hz Means are provided for determining a signal, which corresponds to a polar magnetic field pulse, and that to determine the presence, the identity or the state of the Object is used »whereby the amplitude and the time characteristic of at least one of the signals is determined.

The expression "open strip ¹¹ " denotes a strip which, after magnetization, has separate poles, ie the strip is not closed or shaped into a coil. For a particular responder, the predetermined peak intensity of the test field is the Mindeet field, which is a reversal of the Can cause magnetization of the marking agent.

^{The expression "ferromagnetic 11} " used in the present specification is intended to encompass both conductive and non-conductive materials, iron and its alloys with nickel as conductive materials and ferrite as non-conductive materials these can generate ten times stronger external magnetic fields than the non-conductive materials. A marker made of conductive material can therefore be made smaller than that of a non-conductive material. Small markers are also cheaper and can be hidden away. They are particularly important for preventing sound thefts.

It has been shown that «read an open strip from you ferromag & etlachen material, if you have enough attan la. reference

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a characteristic impulse of an external polar magnetic field is generated when its magnetization is reversed under the influence of a technical idea, the change of which exceeds 300 oersted per second described responder, the responder consisting of an * open stripe cannot be reliably differentiated by means of a single frequency or a ratio τοη two frequencies to one of the «Ss it has been shown that the amplitude of a certain harmonic τοη of the AKpIi ¹ IiUl * and the frequency of the acting suffering depends as well as the tone of the orientation of the responder "in relation to this field · With a selected band of suitable frequencies, however, a responder according to the invention can generate a signal that has distinguishing features" which are essentially independent τοη the orientation of the responder as well as τοη the Amplitude and the frequency of the acting field "The responder according to the invention is actually frequency-independent up to the extent that it generates the signal that is characteristic of it, unless another, for example a pulsed field is used instead of a sinusoidal field"

If a sinusoidal field acts on an open strip according to the invention, an outer polar pulse is generated, which can be distinguished by the total flux components in a band whose lower limit (the predetermined frequency) exceeds t000 Hz and whose width is at least ten times of the field frequency, so that with certainty a statistically representative group τοη frequencies is obtained «A signal that shows the entire change in the flux components within the band over time (a" magnetization recovery signal ^M ), e.g. the voltage induced in a coil linked to the flux, is very narrow and is less than 0.1 milliseconds at half an amplitude *

The signal generated τοη the open strip has yet another distinguishing feature, namely occurs at a certain composition and with a certain size and shape of the material the aplitude peak of the signal

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Influence of a ·· Weohselfeldee with a certain waveform for a predetermined time after each wave of the field. This feature dee signals scarcely be further defined by the absolute instantaneous value of the applied field · s at the time in which the Mettoaagnetieierung dee open strip has the value Hull, exerts Hypotheee according takes place in the ·· * time, the "reversal" of the magnetization, which, in our opinion, corresponds to the peak of the magnetization reversal signal. In the following part of the honor, this instantaneous value of the acting field is referred to as the "alternating atroacoustic force" of the material, although it must be noted that the alternating electric force depends not only on the magnetic properties of the material but also on the waveform of the acting force. ld ··· This expression, however, is a suitable means of comparing the addresses of different open strips subject to the same affliction.

The open strip according to the invention can consist of a thin Tape or a wire of a ferromagnetic material with a magnetic moment of at least 0.1 electromagnetic unit. The characteristic dimensions, i.e. the Length in relation to the square root of the cross-section of the band or of the wire · should have at least · 150 · At ratios below this value, the internal self-demagnetizing field effect · with highly magnetic materials can increase the acting field to more than 20 oersteds. If the conditions are below 150, the amplitude of the magnetization reversal signal drops sharply and is noticeably dependent on the orientation of the open strip in the acting field

The corresponding criterion for a thin flat slice from a ferromagnetic material would be a ratio of geometric characteristic dimension sur thickness τοη at least 6,000. Conductive tape or disk-shaped responders should have a thickness of approximately 0.1 to 150 microns, while wire-shaped · conductive · specials should have a diameter of tob Should be 10 to 300 microns. With larger dimensions, the amplitude of the magnetization reversal signal decreases, and

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the width becomes larger at half the amplitude and can finally ' not very differentiated are τοη IT inversion signals, the by ferromagnetic metal objects that May be carried by people.

Sin thin, fluffy and narrow responders are particularly suitable for books in libraries, as the responder is in the Spines inserted or wiped between two book pages can be and thus remains hidden. A book is generally provided with two pairs of τοη torso leaves that go through a fold with each other running over the entire length connected are · This · false are usually wider than a open strip, so that IaIs a responder easily can be hidden. If the responder is provided with an adhesive coating and a pad on both sides, so it can be used close to the bandage between two sides will.

The preferred number and the relative orientations of the geometric characteristic dimensions of the markings depend on the features of the acting field in a quiet manner to be explained below. For the purposes of the present description, an idealized marker with one major dimension will be referred to as a "one-dimensional" marker, while a marker with two mutually perpendicular major dimensions, xB _# in the form of an "L", "Ϊ" or "4-", will be referred to as sweidimensional marking means and a responder with three mutually perpendicular main dimensions as a "three-dimensional" marking means or responder is referred to.

open strips can be entirely inorganic or consist of a ferromagnetic laminate held in place with an organic adhesive, or the strip can also from a dispersion of ferromagnetic particles in one organic binders, see B. Vinyl chloride. The responder can also mm «several at a short distance from one another separate ferromagnetic strips exist, the position of which is fixed to one another, or which are embedded in "in non-magnetic material, see B. as very fine «wire threads or

Ribbons in a piece of paper ©

Another embodiment of a responder consists of two or more open strips with different AC coercive forces, which are used as a unit. Even if such united open strips with each other are in contact, they influence each other magnetically but not so strong, so each strip is its own can generate characteristic impulse.

Another responder suitable for the Zweck® of the invention consists of one or more of the described open strips together with at least one "sterer" - »element» with the help of which a responder can choose to sensitize or desensitize can be. Sensitized is a condition in which the responder is under the influence of a field a characteristic signal is generated, and vice versa with deeenibilized denotes a condition, in which the responder this characteristic signal is not generated but instead

either another divorced signal, or at all no signal.

As has been shown, there is a possibility that the magnet! - to prevent or change the inversion of a responder, therein, the field acting on the open strip is effective preload by having a remanently magnetizable control element Material is used. In the case of remanent magnetization, the field of the control element acts alternately. strengthening or weakening for the EeId acting on each other following half-periods. If a sufficiently strong remanent field is generated on an open strip, that is sufficient Hettofield in the half-period in which the remanent "field counteracts the outside field, does not prevent a reversal of the Magnetization of the open stripe in the characteristic. Way to effect. Reversing the magnetization of the open Strip for; every change of the Weehselfeläe® does not need to be complete to be prevented ”, rather“ the reversal is sufficient to be changed so that the resulting signal is not characteristic of a responder »Dementeprecliemi needs" such a magnetic control iie flee * d @ s open

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Not to completely cover the strip. For example causes one magnetizes it control only on a central part of an open strip that segments on both Pages behave roughly like two independent strips. The part located in the middle should therefore be sufficiently large and arranged in such a way that none of the segments meets the aforementioned ratio criterion.

You need remanent magnetization of the control not to be uniform, and in fact, unevenly magnetized controls are generally desirable because of their Use that is less expensive.

An unevenly magnetized control has, for example exhibits a series of bands of remanent magnetization, with adjacent bands being oppositely polarized. In order to keep internal demagnetization effects low and to generate the strongest external magnetic field, preferably the directions of magnetization of the bands of a control element magnetized in this way parallel to the length of the control element get lost.

A control element can be used to re-sensitize a responder magnetized in the conventional manner. For example, to magnetize a control evenly, you could the element can be exposed to the action of the field of a strong permanent magnet. Purely a band-like, uneven one Magnetization of a control element, the element could be exposed to the action of a series of permanent magnets, adjacent permanent magnets are oppositely polarized. When removing the magnetizing magnets a certain amount of Caution should be used. A movement of the magnetizing magnets along an axis parallel to the magnetic poles would be lead to a change in the desired magnetization with the consequence that the magnetic influence of the control element up to is decreased to the extent smaller than that for de-sensitizing of an open strip required extent · When using a single pulsed magnetic field, its YeId distribution is similar to the field distribution generated by permanent magnets, for magnetizing marking means

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the difficulties mentioned can be avoided, since in this case no controlled movement is required between the marking means and the magnetization source. Devices for generating such fields are known per se. ^{The "overdamped H} discharge of a capacitor through a coil is given as an example.

A conventional one was used to sensitize marking agents Demagnetization device can be used with the on the marking means a relatively high frequency Magnetic field with decreasing amplitude jsup brought into action will. For example, a device can be used that has a "underdamped" discharge of a capacitor through a coil causes (d * h · an interconnection of a coil with a capacitor same as the circuit used to magnetize a control, but with a high Q value On the other hand, a degaussing device can also be used be used with a string of permanent magnets, which are polarized in the opposite direction »If a control element is train on such a degaussing device along a When the legs of magnets move the common coordinate, a magnetic alternating field © in · Through acts on the control element A suitable choice and arrangement of the magnets can generate a field with a decreasing amplitude in the demagnetization device will. Are magnets of different strengths used and arranged in such a way that their fields lend in the direction of movement gradually weaker »so the amplitude of the magnetic field apparently disappears, if, the arrangement over a control is carried away »The same result could also be achieved by using equally powerful magnets be arranged in steps or in an inclined plane, so that the amplitude of the magnetic field gradually decreases

Sa the external magnetic field of a St © uer <tleiieB.t # e depending äem pattern of magnetization verändarlich s®ia kmm ₀ so Eis® degaussing the control element in the strictest Siane in general is not required, but the "egpsatleÄ® influence dee Steuerelement60 needs to be reduced only to the AmeisaS that ua® eiawirlctiaie IeIt fiea offtaeB 9treif # & ummagneti "- ·»

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can eggs.

The coercive force of the control element should be at least 5 Oe and the element should be in the case of remanent magnetization

a static external magnetic field of at least 3/4 Oe above be able to produce at least a part of an adjacent open strip · In order to simplify manufacture, can Control consist of a thin, magnetic and uniform coating of a gamma iron oxide powder in a vinyl chloride binder on one side of the open strip.

After other desensitization procedures, the open Strip so deformed or torn that its resulting longest linear section is less than the length required for the said ratio length ι square root of the cross section is required. A marking element can also be deseneitized by stretching the open strip to change its magnetic response. For example, an open strip can be used together with a heat sensitive bimetal strip or as an element of such a bimetal strip be used.

A responder with one or more open strip but without control is hereinafter referred to as a "Einzustands ¹¹ responders, while a responder is referred to by one or more control elements and having one or more open strip hereinafter referred to as ⁿ Hehrsu8tands ^N responders.

If a responder is passed through the effective field, the responder must be influenced in at least one and preferably in several places when moving through the monitoring zone in such a way that the open strip of the responder is reversed. Its absolutely safe orientation would be achieved with a "one-dimensional" field of action together bit a "three-dimensional ¹¹ responder, the strength of the field of action at every point in the monitoring zone being at least 1.4 times (root 2) of the switching field of the marking elements A one-dimensional field is a PeId in which all magnetic lines of force in the monitoring zone run parallel to one another.

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A one-dimensional panel has two perpendicular to each other Directions that also run perpendicular to the direction of the field, In which directions there are actually no components of the field of activity. Likewise, exhibits a two-dimensional Field only has one direction in which no components of the field of action actually run, while with a three-dimensional field Field no field components run in any direction. From this it can be seen that with a combination of a one-dimensional Responders with a three-dimensional field and also a two-dimensional responder with a two-dimensional en field and a three-dimensional responder with a one-dimensional field an absolute "orientation" to each Position in the surveillance zone is reached with certainty.

With such combinations, the path of the responder through the surveillance zone can be very short and only slightly longer than an open strip. If the .Veg is extended, it would be a Such an ideal combination, with which the responder is sure to be orientated at every point in the surveillance zone is not required. To ensure that the Movement of an open strip through a surveillance zone over a relatively long distance at least one magnetic reversal takes place, it is only necessary that the vectors of the magnetic field components are greater than the switching field of the Marking element in each direction at some points in the surveillance zone.

This condition can be met in that three One-dimensional fields are generated, each of which is oriented to a different coordinate axis in space. On the other hand, the required condition can also be met by that in the movement path through the monitoring zone several Districts are preceded in which the orientation of the field of action does not change, but the fields in successive districts have a different orientation.

In addition to the length of the zone through which the open strip is intended to move, there are a particular facility for building other important and interdependent changes

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borrowed, with which it is secured that when moving an open Stripping through the monitoring zone at least one magnetic reversal takes place, which variables consist of the speed of the open strip, the number and orientation the characteristic geometric dimensions of the open strip, from the frequency of the effective alternating field the peak intensity of the field, and from the vector components of the field at any point in the surveillance zone at any point in time.

The magnetic alternating field can according to the conventional method are generated for example by supplying an air coil or the coil of an electromagnet with alternating current and by moving a permanent magnet in such a way that its magnetic field changes polarity in the monitoring zone.

A device and method for creating it became a magnetic field is determined that allows the effective field to be limited to an intensity that is not much stronger is than the minimum intensity. In one embodiment of the Device according to the invention, several individual fields are generated in sequence, which together form a field component in almost in every direction and almost at all points in the surveillance zone »In a further embodiment, according to the invention only generates two electromagnetic fields · The field lines of these two fields run almost everywhere in the Surveillance zone at right angles to each other. At a field intensity which is 1.4 times (square root of 2) the minimum intensity, actually exists in many directions at every point in the monitoring zone at least the minimum intensity · At each point, that of two field lines that cross each other almost vertically With such an intensity determined, the fields have a component in each direction in which the two fields comprehensive level. The device according to the invention also creates a relatively large surveillance zone

For a specific purpose, the device according to the invention generates fields whose frequency period (the one-time excitation of the device required time) is chosen so that at an assumed speed of the fiesffnders

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the lines of force of each. The field is essentially the same Maintain direction for a distance equal to the distance traveled by a responder during a sequence period would. In effect, this route becomes a "place" in the surveillance zone. The sequence period can be made very short so that fields with generally curved lines of force can be used »

The device for generating an effective field in a zone has a plurality of electromagnetic field generating means. Each field-generating means generates an electromagnetic field due to the supplied electrical energy, its lines of force generally curved in a zone »The direction of each field line at essentially every point in the zone differs from the direction of at least one other field at this point. Funds are provided to support the Supply field-generating means sequentially with electrical energy. The difference in field sightings depends from the total directions that have to be provided and from the number of fields to be generated. Should only two Fields are created, and all directions should be in one plane, so fields of the minimum intensity are used the directions should differ from each other by 90 °. If more fields are generated, the directions be reduced differently between two fields »

Each field generating means can have at least one straight line Head consist. If a field-generating means consists of more as one conductor, the conductors are arranged parallel to each other. The heads of the various fields-generating means preferably run parallel or at right angles to each other. If the conductors run at right angles to each other, the Crossing points preferably arranged at a distance from the relevant ends

A suitable agent is for obtaining parallel conductors in the use of parallel portions of a generally rectangular abrasive ·, which consists of a coil, either generally, "for the form of a ^w o ⁿ or a" ⁹ S "wound ·

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Such coils are hereinafter referred to ^{simply as n} o "coils or" 8 ^{M coils.} Parallel sections of the coil are then used as long »straight parallel conductors. An embodiment made from such rectangular coils has at least one ^H o ^M coil and at least one ^H 8 ^H coil. The relevant sections of the coils run parallel and essentially in the same plane and are at a distance from one another in this plane. If the coils receive current one after the other, they generate fields, the directions of which run essentially at right angles to one another almost everywhere in a relatively large zone.

For critical uses where a high degree of certainty is required in generating or changing the characteristic response of a kesponder, a preferred embodiment of the invention is provided which is equipped with three electromagnetic field generating means which receive power in sequence. Each field generating means generates an electromagnetic field in a zone , the lines of force of which are generally curved within the zone. At every point in the zone, the directions of the lines of force of the three fields are essentially perpendicular to one another. A device which generates two fields, the lines of force of which are substantially perpendicular to one another at substantially any point in the zone, are hereinafter referred to as "two-dimensional field" generating devices.

In a preferred embodiment, a device generating a three-dimensional field has two ^H 8 ^N coils and one "ο" coil. The parallel end and middle sections of the first "8 * coil act as long conductors and generate a first field. Only the field ^{that is generated by the middle section of the second H} 8 ^H - ₈ coil is required as the second field. Both coils are suitably designed flat and are close to one another in substantially parallel planes. The two "8" -. 3puleu. are arranged at right angles to one another, and their middle sections intersect at the height of their midpoints. The parallel sections of the "0" which generate the third field -Scoils run parallel to the ind and middle sections

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the first "8" coil. All parallel sections of the ^Il o ^w --Sp "le run between the Bittel portion and an end of the first" eight sections ^W -Spule.

Another »device generating a three-dimensional field has two ferromagnetic linear electromagnets, which are arranged at right angles to each other and approximately each other cross in the middle, as well as an air core whose circumference runs close to the poles of the linear electromagnets

The field-producing means are sequentially supplied with power to generate a pulsed field, wherein a sinusoidally varying power source was from the switch a means for next media · Bas field produced by any means during a continuous power supply will hereinafter be referred to as "field pulse ¹ * · Furthermore, in those devices in which each field-generating means is provided with a coil, field impulses were generated by discharging an underdamped LC circuit Means are provided which supply the LC circuits with electrical energy one after the other. When this energy is discharged via the LC circuit, an underdamped sine wave field pulse is generated Field pulse off Every field-generating means and every field pulse consists of a sinusoidal field, the direction of which changes several times. However, it is pointed out that with an overdamped LC circuit the direction of a pulse would not change, but with each discharge it would overdamp Circuit a single rectified pulse can be generated

Is it should also be noted that a sequence period does not need to be equal to the sum of all field pulses in terms of duration. It has actually been shown to be in some cases It is desirable to include a continuous interval with a duration of at least t seconds in each sequence period, in which no field is generated. Eb has been shown through that

009886/1548

the activation of this one-second interval Work of a so-called heart pacemaker from the fields the device according to the invention is not influenced.

It is generally required of the flux monitoring device and the detector circuit that the magnetic flux changes in the monitoring zone are monitored, and that the magnetic flux changes generated by a responder are distinguished from all external magnetic flux changes. External flux changes include the applied field, the lump generated by electric motors, the noise generated when a circuit breaker is operated, etc., the effect on the sensor depending to some extent on the strength and distance from the monitoring zone. There are monitoring devices for the magnetic flux, which directly display the frequency of the change in the field, and other devices which display the momentary strength of the field, from which display the alternating frequency can be derived. The latter devices include magnetoresistive devices, devices using the Hall effect, and magneto-diode sensors. Both types of devices can be used together with flux collecting devices to improve sensitivity. In such a device, at least one coil is provided with which the magnetic flux is inductively determined. A large coil with a few turns can be used, and even with only one turn, or several small coils can be used, each coil having relatively more turns. Small coils make the door pull so that they are less sensitive to magnetic puffing caused by electric motors and circuit breakers. On the other hand, a large coil speaks more evenly to one responder to different! Place in the zone · as «islands · small coils. Any number of opposing coils can be provided so that magnetic fluff from a distant source can be minimized while detecting a responder that is closer to one coil than another. If several coils are used, these can be provided with individual detectors, or the coils are sequentially connected to a common one

009886/1560

Detector connected.

The signal detector assigned to the positive monitoring device In its simplest form, shows the presence of a Responders in the surveillance zone by determining the time and the amplitude characteristics of a signal corresponding to a single magnetization reversal of a responder. As already executed, a responder according to the invention generates a unusually narrow signal and a signal that occurs for a specific field of action while a responder is with a certain alternating current coercive force a signal at a predetermined point in time after a change in the field of action generated · By determining signals that are within a predetermined Intervals occur and have a minimum amplitude, and which begin and during a minimum interval end, the detector distinguishes between noise, the signals generated by the responder and external signals from others Objects that respond to an alternating magnetic field.

The predetermination of the point in time at which the characteristic signals generated by a responder occur Furthermore, to equip the detector circuit somewhat more extensively as a safety factor against false alarms. The reference means for measuring successive signals can be a preceding Signal, the phase or the time of the effect feces The alternating points of the field of action can be used appropriately for this purpose · Furthermore, in the Monitoring zone a responder can be permanently arranged, the generates the reference signal. The time intervals between the signals as well as the individual signal characteristics therefore show reliably the determination of a marking agent on · If both options are provided, then · in fact, wrong Alarms free system can be set up

In the case of a theft prevention system, of course, mandatory action must be taken as soon as it is an apparently stolen item is discovered. The too appropriate special measures depend of course on the work wise the device according to the invention. These measures eggs can emerge from the photo

009886/1540

the person in the growth zone, or there will be one automatic device for opening the doors put out of operation.

The determination device can consist of a circuit, which is responsive to at least one signal that has a minimum amplitude and a smaller than the maximum width. You can also determine the time of occurrence of the circuit Monitor signals with respect to the time characteristic of either the action magnetic field or a reference signal associated with is correlated with the magnetic field signal. The same circuit can be used for both single-state reaponders and multi-state responders As already stated, the signals generated by an open strip when an associated control element is demagnetized have essentially the same amplitude and width as those of one Stripes generated signals that are used as a single-state responder. However, if the control is magnetized, the shape, amplitude and time of occurrence of the Signal is changed, the τοπ open stripes are generated The detector circuit can therefore essentially determine the magnetization of the control element

If the device according to the invention is used to prevent a Theft τοη books used from a library, so can dl «books are desensitized by using a multi-state specifier during a review, so that the Book can be taken from the library. When the book is returned, it can be sensitized so that an inadmissible removal of the book from the library is prevented.

With such sensitization and desensitization does not need the exact · position · of the particular person to be known be su. By "in" skillful "and hidden arrangement" ines or several responders on an object can according to the invention against "in" deception by covering up or be effectively protected by removing the responder *.

The invention will now be described in detail. In the attached drawings is di «.

009886/154 8

1 shows an overview of a system for preventing theft or an unauthorized removal of objects from a building, with the system at the exits of the building is arranged,

2 shows a representation of two long, straight and parallel ones Ladders and the lines of force generated by a current flowing in the ladders,

3 shows a representation of four long, straight and parallel ones Ladders and the lines of force drawn from that in the ladders flowing electricity are generated,

FIG. 4 501 , a schematic representation of two generally rectangular "o" coils, and 503 a diagrammatic representation of 501 and a zone in which the field lines of the coils run almost at right angles to one another,

Fig. 5 505 , an illustration of a grid formed by three superimposed coils and consisting of two generally rectangular "8" coils and one generally rectangular "o" coil, 507 . £ 0 £ and 511 each a representation of the coils of the grid 505.

FIG. 6 502 , a representation of two coils according to FIG. 5 and a cross section through a zone in which vectors represent the fields which ^{are generated by the "horizontal 11} sections of the coils shown in FIG. 5, 504 a representation represent the coil shown in Figure 5 _e, which is not shown in 502, and a cross-section through a zone in the vectors of the field, the vertical from the ^w middle portion ¹¹ is a generated ^M shown in Figure 5 8 "coil ,

7 is a front view of a preferred embodiment of a field generating means used in the device according to Fig 1 _e,

Fig.S a schematic representation of the windings of a part the field-generating device shown in Figure 7,

Ö09886 / 1548

Fig «, 9» 10 each shows a representation of the magnetic fields generated by the in the device shown in Fig. 7 are generated,

Pig · 11 shows the superposition of two groups of Magnetic field lines from the one shown in Pig · 7 Facility are generated,

Mg.12 a circuit diagram for a device with which several,

en an electromagnetic field generating device of the One after another to be supplied with electrical energy, and

13 is a circuit diagram for a preferred embodiment of the the magnetic flux monitoring device and the signal detector in the system according to Fig.1.

A preferred embodiment of a multi-state hesponder, which can be particularly used to protect the book inventory of a library, consists of an open strip of annealed permalloy tape with the composition of $ 4 molybdenum, $ 79 nickel and $ 1 iron and with a thickness of 25 microns, a length of 18 cm and a width of 0.6 cm. There is a control or control element provided from a gamma iron oxide strip, which has the same width and length as the open strip. Such a control or monitoring element can be generated in such a way that first 100 parts by weight of a gamma iron oxide pigment used for audio tapes and 2 parts by weight of a wetting agent such as Boss and Rowe Yelfcin TTS are dispersed in a solvent such as toluene, with a 25 A mixture containing solids is produced. 50 parts by weight of a resin composition are added to this mixture, ζ _β Β _β 75 $ of a copolymer of 89 parts of vinyl chloride and 11 parts of vinyl acetate (VYHH) and 25 ^ dioctylphthalato Methyl ethyl ketone and toluene can be added as required. The solution is applied by means of a doctor blade to a removable paper sheet-like base coated with silicone. After the solution has dried, the backing is peeled off and all controls are used.

609886/1548

often

Manufactured to a uniform thickness of 230 microns. If the thickness of the described open strip is more than 230 microns so the open strip can be desensitized when the control element is magnetized by a magnetron magnet with a gap of 25.4 mm. These controls are then layered together to form an open strip ο For the production in large quantities, the mixture can be applied to a wide sheet of the material of the open strip from which strips 0.6 cm wide are then cut out.

The Fig.1 shows three units 10A, 10B and 1OC, which are so arranged are that they form two exit paths, with the spaces between the opposing units 10A and 10B and between 1OB and 100 each form a "monitoring zone".

The unit 10A is partially cut open so that two Electromagnets 12A and 12B, one air core coil 14- and four smaller ones Coils 16a, 16B, 16C and 16D can be seen. The electromagnets and the air-core coil form a device that generates an effective field with a connection contact (referred to as input contact), which is connected to the ungrounded (hot) conductor 18 of a filtered AC power source, and to an "output contact", which is connected via the conductors 22, 24 and 26 to a field sequence circuit 20, of which only those with the Unit 10A connected conductors 22A, 24A and 26A are shown. The units 10A and 10C have the same structure, while the unit 10B differs from the other units in that it is not equipped with the four smaller coils is. These smaller coils each have 900 turns of magnet wire with a diameter of 0.1 mm have a diameter of 10 cm and form a magnetic marked 29 Flow monitoring device, these coils are connected in series with a coaxial cable RG 58 A / U, at separate points placed on one side of the surveillance zone and very carefully oriented so that from the magnetic noise generated by the field generating device and other sources as much as possible is filtered out. In the illustrated embodiment, the upper coils 16A and 16B are perpendicular

009886/1548

oriented, while the lower coils 16C and 16D are oriented horizontally. Each coil is provided with one not shown and 12.7 micron thick aluminum foil wrapped around a shield against electrostatic noise, but allows the passage of magnetic signals. These shielding foils are connected to the shield of the connecting coaxial cable.

A signal detector 32A is connected to the magnetic flux monitoring device of the unit 10A via a coaxial cable 28.

he

sen, and an equal signal detector 32b is available via a coaxial cable 30 in communication with the magnetic flux monitor of unit 10C, a sensitized responder is used carried through the field of action in a surveillance zone, so the responder is remagnetized with each change of the effective field and generates an impulse of an outer polar one Magnetic field. The plus monitoring device in this zone responds to this change in magnetic flux in the zone and generates a signal which corresponds to the pulse and which is passed to the associated detector circuit 32. The detector circuit generates due to the special amplitudes and time characteristics of the Marking signal, a signal that sets an alarm and display circuit 34 in operation.

The Pig »1 shows in general the spatial arrangement of the field-generating Device and the plus monitoring device, which devices form monitoring zones that are in a Library are arranged, the books are equipped with a responder according to the invention. They are special river monitoring devices and field generating devices are shown, although other such devices are also in accordance with the invention can be provided. The field-generating device can, for example, also consist of a grid-like or other arrangement of There are ladders, an arrangement of which is shown in Pig.2 is to generally show the PeId generated by long straight conductors.

Pig. 2 shows a section of two long, straight and parallel ones Conductors 512 and 514 with the lines of force leading from that in each

.009836 / 1-54.8

J *

flowing current can be generated at different time intervals. The circular line 513 represents only one line of force in a series of circular lines of force that flow from the in the conductor 512 Electricity can be generated while the circular line 515 is just one line of force of a series of concentric and circular lines of force which are generated by the current flowing in conductor 514. For the purpose of simplifying the illustration, FIGS 2 shows only the magnetic flux lines. For the same reasons, only the magnetic properties of the electromagnetic field treated «.

As can be seen from Figo2, run in the interrupted line 517 enclosed district 510 the field lines the two conductors 512 and 514 although curved, but essentially at right angles to one another at the crossing points. The district 510 represents a cross section through a surveillance zone and is therefore represented at right angles, since this is often the case is the shape of the cross-section of a passage in which the surveillance zone generates an electromagnetic field shall be. Entrances and exits, corridors and similar passages generally have such a cross section.

Assuming dimension 519 of district 510 corresponds to the width of a passage, and that the conductors 512 and 514 are oriented perpendicularly, the correspond to Dimensions 519 and 521 of the width respectively. the length of the surveillance zone. The considerations in determining the actual The length of the surveillance zone has already been explained. As is well known, the intensity of the field changes directly with the Amplitude of the current flowing in the conductor and vice versa in relation to the distance from the conductor. For a special pass with a width 519, with a distance of the conductors 512 and 5H from one another which corresponds to the dimension 523, and whose distance from the edge of the passage is equal to the distance 525, and for a particular one requiring sufficient energy Eesponder can analyze each of the fields at their crossing points at the furthest point in District (near the dimension 521) can be determined, which amplitude of the current flowing in the conductors 512 and 514 have

009 886/1548

AS

3 shows four long, straight and parallel conductors 516, 518, 520 and 522 and two groups of magnetic field lines which could be generated by the current flowing in the conductors. One group of the flow lines is shown with solid lines and the other group with broken lines. The solid lines are the lines of force that would be created if currents were to flow in opposite directions of the same magnitude in conductors 516 and 518 while conductors 520 and 522 did not flow. The field lines shown with broken lines are generated with a reversed current flow j d.ho, the conductors 516 and 518 are de-energized, while currents of the same strength but in opposite directions flow in the conductors 520 and 522. It is pointed out that, given the same dimensions in FIGS. 2 and 3, the field in FIG. 3 has a greater length (521); however, both fields can be generated in the same period of time (in both cases only two "field pulses" need to be generated) »The analysis to determine the current requirements of the two conductors in Fig. 3 is carried out generally in the same way as with reference to the Fig. If another "set" of such an arrangement of conductors is provided and these two sets of conductors are arranged in closely spaced parallel planes so that the conductors of the respective sets are perpendicular to each other, a three-dimensional device is created. In such a device is at essentially any location in the district 510 at least once during each pulse sequence of the four pulse fields, each 'of the three on each other nearly perpendicular magnetic fields "The ⁿ end" conductors of said further set of conductors is in Figure 3 with shown in broken lines and denoted by 527. ·

Figures "Figure 4 shows a two-dimensional field generating means, which is designated with 501 and two ^H o" _Spulen 524 and 526 having ". For purposes of analysis, the vertical portions of the coil are considered to be long, straight and parallel conductor. The coils 524 and 526 are in

009886/154 8

- 22 -

ίο

however, they overlap substantially in the same plane in such a way that the distance between the adjacent sections 528 and 530 belonging to different coils is much smaller than the distance between the vertical sections of the same coil. In this way, the field lines between the vertical sections located on the inside are approximately the same as the field lines shown in FIG. At 503 , a zone formed by such unevenly spaced coils is shown, which has the length 521, the width 519 and the height 534. If the coils were equidistant from one another, ie "if the distance between the inner sections were equal to half the distance between the vertical sections of the same coil, fields would be generated with the field lines shown in FIG. 3". It has been shown that with such unevenly spaced coils with a length of 105 cm of the vertical sections and with 120 cm long horizontal sections, which coils consisted of 10 turns of a wire strand No. "10 A.Woss" (like both No. 30610), An essentially two-dimensional field can be generated in a monitoring zone which has a height of about 90 cm, a width of 90 cm and a length of 150 cm when a pulsating undamped sinusoidal current with an initial peak amplitude of 180 amps is passed through the coils became.

A device generating a three-dimensional field is shown in FIG. The device shown at 505 has a grid-like structure 539 which consists of three coils. In the preferred embodiment, the coils are located in parallel and closely spaced planes. The coils are at 507 . 509 and 511 shown individually. The grid has three vertical components 540, 542 and 544 and five horizontal components 546, 548, 550, 552 and 554. As will be seen from the following description of these components, each of these components consists of at least one section of a coil, and most of these components comprise sections of a plurality of coils. It should be noted that those fields are not required that

Q09886 / 1548

from the coil sections forming the constituent parts 540 and 544. However, these fields are created and shorten the "length" of the zone when components 540 and 544 are located sufficiently close to component 542. In those cases where a component consists of a section of more than one coil, only the field of one section is required. Therefore, only the required fields of the individual coils are dealt with below. In Figure 5, an upright and generally rectangular "8" coil 555 is shown at 507. The coil consists of a conductor wound in the shape of an "8" forming two generally rectangular and serially connected portions of nearly equal size, indicated generally at 558 and 560, and having substantially parallel obar and lower lengths. Part 558 has an upper length 572 and a lower length 574, while part 560 has an upper length 576 and a lower length 578. The lower length 574 of the loop 558 and the top length 576 of the loop 560 together constitute 555 · Doe upper and lower lengths of the parts 558 and 560 and that the upper length 512 "and the lower length 578 of the central portion of the" 8 "coil form the end sections of the ¹¹ 8 "coil 555 · Energy pulses can be fed to the coil via the connection contacts 580 and 582. The arrows shown in the two loops, one of which is labeled 584, indicate the direction of current flow through the various sections of the loop for direct current. From the sub-figure 507 it can be seen that the length 572 corresponds to the horizontal component 54b, that the length 572 corresponds to the horizontal component 546, that the lengths 574 and 576 correspond to the horizontal component 550, and that the length 578 corresponds to the horizontal component 554 . The sub-figure 509 shows a ^M o "coil 557" whose horizontal sections are denoted by 586 and 588, and which correspond to the horizontal bed parts 548 and 552 of the grid 539 (sub-figure 505) ... In the sub-figure 511 one is to the side rotated "8 * - coil shown. The lengths of the coil labeled 594 and 596 correspond to the vertical component 542 of the grid

539 (505.), while lengths 590 and 592 denote components

540 resp. 544.

009836 / 154B

203-356

Pig. 6 shows vector representations of the magnetic lines of force for the fields which are generated by the device generating a three-dimensional field (coils 555, 557 and 559 according to FIG. 5). In subfigure 502 field vectors are illustrated in a plane of the coil also extends both parallel to the "vertical" lengths (for _e B ₀ 594 and 596) and perpendicular to the plane of the coil, and a side view of the lengths of the coils 555 and 557 The coil 559 is not shown. A region 539 of a cross section is shown with dashed lines. Field vectors are shown at three arbitrarily selected points 610, 612 and 614. The vectors labeled "a ^M " correspond to the field produced by lengths 572, 574, 576 and 578 of coil 555, while the vectors labeled "b" vectors correspond to the field produced by conductors 586 and 588 of the coil 557. The field vectors of the field generated by the third coil 559 are shown at 504 at points 610, 612 and 614, the field being viewed in a plane parallel to the horizontal lengths of the coils and perpendicular to the The coils 555 and 557 are not shown, the region 510 is shown again with broken lines and the vectors of the field of the coil 559 are designated as "c" vectors. The sub-figure 504 shows the one in the middle located lengths 594 and 596 and the end lengths 590 and 592 of coil 559. Dimension 521 of district 510 is only part of the way from two middle sections 594 and 596 to end conductors 590 and 592. This is t is a consequence of the fact that in the end conductors 590 and 592 the current flows in the opposite direction than in the conductors 594 and 596. In the conductors 594 and 596 the current flows in the same direction, so that the two conductors as a single conductor can be treated. In such an "8 ^M coil, the distance between the conductors 594 and 596 of the central section and the end conductors 590 and 592 can be changed by changing the dimension 521. The field vector diagrams shown in FIG. 6 at 502 show that the coils 555 and 557 generate a two-dimensional field at points 610, 612 and 614, while the field vectors shown at 504 show that

009886/1 543

ORtGINAL INSPECTED

the field of coil 559 adds a "third dimension" to the field Has.

In an embodiment of the device according to FIG. 5 used to discover responders according to the invention, where the surveillance zone consisted of an area leading to a passage, a surveillance zone with a height of at least 150 cm, with a width of 60 cm and with a length of 75 cm (dimensions 534 »519 and 521). The grid formed by coils 555, 557 and 559 had the following dimensions: the vertical components 540, 542 and were 180 cm long, while the horizontal components 546, \ 548, 550 and 554 had a length of 150 cm exhibited. The ^M o "coil M was centered around the intersection of the central sections of the '^''coils, and their lengths 586 and 588 were spaced 53 cm from the lengths 574 and 576 of coil 555. All of the coils 555, 557 and 559 were made from a vinyl insulated wire strand Kr · 10 (both No. 30610). The coil 555 consisted of 6 turns, the coil 557 of 10 turns and the coil 559 of 7 turns.

It should be noted that the planar structure shown in FIG. 5 can be manufactured without great expense and can be clad in such a way that it has a pleasing appearance. Such a structure can be placed on one side of a passage leading to a door without difficulty ”. The loading M specified structure has still the further advantage that the coils can thus be "calibrated" easily, that between an energized coil and the other two non-excited coil inductance occurs only a small or none. The energy generated by a coil is therefore actually available to generate a field which is effective in a surveillance zone.

Fig. 7 shows a front view of a field generator and the flow monitoring device according to FIG. 1. The electromagnets 12 of the field generating device consisted of iron bars with a cross section of 5 »1 cm, which were surrounded by coils. The bars were made of sheet metal with a thickness of. <·; 0.457 mm made of transformer sheet 2 type M-19 susanmiehgeBetat and

. · ■ '-. .. '= 0098.86 / 1 543

ORfGiNAL INSPECTED

^ ι Kv -> 5 -

had a length of 142 cm and a width of 5.0 cm. Each coil consisted of two turns of 125 turns of enamelled wire with a diameter of 0.2 cm, those on the rod Were evenly distributed, as well as from two further windings, each with 60 turns of a magnet wire with a diameter of 0.259 cm at each end of the poles. The two additional windings with 60 turns each were combined with the ones at the end 60 turns of the windings consisting of 125 turns are bifilar wound. This type of winding is shown schematically in fig shown

As can be seen from Figo8, the 60 turns are the Windings 36A and 36B with each other and with the parallel connection of the 125-turn windings 38A and 38B in Switched in series. This combination of windings is hereinafter referred to as “coil winding”, which is provided with an input contact 35 and an output contact 37. It was found that the poles of the magnets were 7 »5 cm from the ends of the rods. Two such establishments, which are arranged at a distance of about 1 meter from each other and have the dimensions mentioned are suitable for the establishment of a surveillance zone with the dimensions of approximately 100 cm 200 cm χ 200 cm.

The air core coil 14 consists of a simple closed loop with several turns. In the embodiment shown in Pig. 7, the loop 14 is circular, the diameter of which is equal to the distance between the poles of the electromagnets 12, while the loop of 80 turns of enamelled wire with a diameter of 2.05 mm is formed. If the electromagnets weren't the same length, the loop would be curved, but designed so that the circumference of the loop is close to the poles of both magnets runs. The reasons for such a measure result from the relationships between the magnetic fields of the electromagnets and the air core coil, explained below.

The i'igures 9 and 10 show the characteristic magnetic fields of an electromagnet and an air coil like the coil shown in Un- PL; - ·. ·, Y in free space, where the '

009886/1548

Lines of force run in the plane of the drawing · According to the representation contains the field of the vertically oriented electromagnet vertical components (parallel to the Y-axis) and close to the poles important horizontal components (parallel to the X axis). The magnetic field of the air core coil also contains components which run parallel to the X-axis and parallel to the Y-axis.

If the air-core coil is moved past the poles of the electromagnet, the two forms of the field-generating means complement each other. This can best be seen in FIG Devices 12A and 12B and H are generated in a zone unit For the sake of clarity, the lines representing the field generated by device 12A are drawn uniformly dashed, while the lines representing the field generated by device 12B are drawn by alternating short and long lines The lines representing the field generated by the device 14 are fully drawn, as can be seen from the illustration at 2_, where one group of lines of force intersects at point m and the other group of lines of force at point n the angular relationship of the magnetic field strengths at point m and at 6 at point η (vectors) len the components r, s and t represent the strength of the magnetic fields at point m generated by devices 12B, H and 12A, while at, 6 the components r ¹ , s ¹ and t ^{1 represent} the strength of the corresponding magnetic fields at the point Represent η by vectors. As can be seen, the components of each group are almost perpendicular to one another, although the directions of the components r, s and t are different from the views of the components r ¹ , s ¹ and t ¹ . From FIG. 11 it can be seen that the vector components of the points of intersection of other groups of lines of force likewise run almost perpendicular to one another. By appropriately selecting the individual magnetic field strengths, the devices 12A, 12B and H could produce an almost exemplary field.

If fields not less than 1.4 times (root generated from 2) of the panel of the open strip, so are

■ '009886 / -! 548 .-' ■■ '■■ ORIGINAL INSPECTED -

203Γ> 356 - 35 -

such fields even at the ends of the surveillance zone at the ends of the polar magnets at which the directions concerned the fields change rapidly, almost exemplary or "three-dimensional". Of course, an absolutely uniform three-dimensional nal field is not required as it is actually impossible to run a responder through an entire zone without that the marking element is aligned at least once to a component of the field of action that is larger than that Control panel of the marking element.

The fields shown in Figures 9, 10 and 11 are generated unless there is an external magnetic influence. In the device shown in Figure 1 with three zone units the middle zone unit works together with the two outer zone units to form two monitoring zones, so that one after the other all nine field-generating means would have to be put into operation so that the fields shown are generated «. Because of the relatively long distance For the reasons already explained, it is not necessary to generate the nine fields in sequence. This actually can be undesirable because the peak amplitude of the currents flowing through the windings of the electromagnets and through the air core coil and thus the cost of the circuit can be reduced by having a field on the same side in each zone unit is generated ο

12 shows a circuit diagram for a device with a power supply part 670, with three power transmission sections 672A, 672B and 6720 and with a sequence control signal generator 683. The circuit is not limited to exactly three transmission sections 672, but this number has only been used to simplify the description a circuit for a field-generating device with three coils according to FIG. 5 or selected. From the transmission sections 672 · nut is shown in detail a section, since all these Abe.chnitte have the same structure "Sinfl the electrical characteristics of the coils differ from each other ά © ^ & ο _9, they have raatersehied-

AEIE Liehe inductive properties, IMD to Seder coil sugeführte energy have the same Bauer wia frequency so

00 9 886 / IbA8

other values can of course be selected for some circuit elements The power supply section 670 suitably comprises an AC voltage source 674 which is derived from the conventional Mains connection 617 can exist, as well as a conventional voltage doubler rectifier 676. This generates a DC voltage with a potential of approximately Hull and minus 200 volts, the voltage across conductors 678 and 680 of the power transmission sections 672A, 672B and 6720 is fed »

The invention provides an electrical circuit that is shown in a conductor (e.g. in the winding of the electromagnet according to Figures 7 and 8, in the air core coil according to Figure 7 and in the Conductors of the field-generating means according to Figures 2, 3, 4 and 5) generates an alternating current, the first half-cycle of which Generates an electromagnetic field, which in turn generates a characteristic signal that can be determined. The electric The circuit therefore generates a damped sinusoidal electromagnetic field in a monitoring zone »The circuit has a parallel resonance circuit, the inductive component of which consists of a conductor that generates the electromagnetic field. Means are provided by which a source of electrical Energy is intermittently connected to the resonance circuit, so that a predetermined amount of electrical energy is generated The resonance circuit is supplied, the energy source is from the resonance circuit switched off, free vibrations consume the energy supplied to the resonance circuit in the form of an energy in the conductor flowing damped sinusoidal current, so that in the As a result, a damped sinusoidal electromagnetic field is generated. The transmitted energy can either be in the capacitive or stored in the inductive component of the resonance circuit. Should the energy be stored in the inductive element the time required to generate sufficiently strong currents results in considerably longer pulses are all generated when the energy is stored in the capacitive Element.

In a preferred embodiment of the invention, the Amount of electrical energy transferred to the resonance circuit limited approximately to a value at which the speed

009885/1548 ORIfflNAUNSPECTED

the dissipation of energy from the resonance circuit is the speed Exceeds, with which the energy from the resonance circuit is stored. This can be done with the help of a silicone-controlled rectifier can be achieved, with which the resonance circuit is intermittently connected to the energy source. Used with the rectifier and a correspondingly selected inductor connected in series with the resonance circuit, no further means are required for Blocking the rectifier and disconnecting the resonant circuit from the energy source is required. You inductance of the inductor should be at least 4.7 times the inductance of the conductor used to generate the electromagnetic field. This inductance should preferably be 4.7 to 25 times and ideally approximately 6 times the inductance of the conductor be. If the difference is less than 4.7 times, the silicone-controlled rectifier cannot be blocked.

In another embodiment of the invention, the Inductor is the primary winding and the inductive part of the resonance circuit is the secondary winding of a transformer® Um with certainty an effective coupling of the two windings with one another To achieve, the transformer can consist of an autotransformer (autotransformer) «In a further different embodiment is instead of an inductor between the bonding agent and a resistor connected to the resonance circuit

As is known per se, the amount of a resonant circuit can be supplied energy can be determined by either the Charge on the capacitive element or the current flowing in the inductive element of the resonance circuit is regulated

With reference to the Pig »12, a description is given below an electrical circuit described »with the one more Circuit interacts so that several of the first-mentioned circuits Can be used to borrow several fields Means of supplying electrical energy »

It should be noted that when switching after the Pig.12 the energy transferred from the energy source Ia first Line in the capacitive element and not in the inductive Element of the resonance circuit is stored® Das Kapazitive

.. ... -. .- ..Q098 8S / 154 8

ORiQiNAL INSPECTED

- 36 -

The element of the resonance circuit therefore exercises a double puncture first of all the energy is transmitted from this element, and secondly, a resonant circuit is formed together with the inductive element, which the rest of the transmitted energy consumed as free vibrations. Because of this double puncture, this capacitive element is sometimes referred to hereinafter as considered a component of the resonance circuit as well as a part of the energy transmission section and accordingly the remainder of this section being the means represents for connecting the energy source to the resonance circuit.

The energy transfer section 672 contains a switch in the form of a transistor 682A, which is switched into the conductive state when a control signal from a sequence control signal generator 685 is fed to the connection point 684A. If the transistor 682A is conductive, then the section 672A forwards an energy pulse to the coil of the associated field-generating device. In FIG. 12, the coil belonging to the energy transmission section bJZA is shown schematically as an inductor 686. If the transistor 682 is conductive, a capacitor 688 stores an energy pulse which is passed on to the field-generating device as a damped energy pulse. The circuit for charging the capacitor 688, which later causes the forwarding of this charge to the field-generating means or the inductor 686 is believed to be novel and includes m an inductor 690, a silicon controlled rectifier 692, and a circuit shown at 694 to trigger the rectifier 692 · The trigger circuit 694 has a normally non-conductive transistor 696, the base electrode of which is connected to one end of the two resistors 698 and 700. The resistor 698 is connected at the other end via a blocking capacitor 704 and a diode 706 to the collector electrode of the transistor 682A Conductor is connected to conductor 678, which has a reference voltage of zero volts. If the transistor 682 is non-conductive, then the value across the capacitor 704 is normally

■■■ '009886/1 5 AB

Voltage approximately 200 volts, so that no current can flow to the base electrode of transistor 696 _p while the transistor remains in the normal non-conductive state. When the transistor 682 becomes conductive, the capacitor 704 is charged, and the charging current flowing through the capacitor 704 puts the transistor 696 in the conductive state until the voltage on the capacitor 704 has reached 212 volts comprises the emitter and collector resistors 710 and 712 of the transistor 696, a capacitor charging network with a resistor 714, a Zener diode 716 and with a capacitor 718. The grid conductor of the rectifier 692 is connected to both the emitter electrode of the transistor 696 and the emitter resistor 710 in connection, so that at a voltage of approximately minus 200 V at the other end of the resistor 710 and at the cathode of the diode 692, the rectifier is rendered conductive or triggered and only when the transistor 696 is conductive »The transistor 696 becomes conductive when the connection point 684 is supplied with a pulse that drives transistor 682 forward inside biases. A current flows from the emitter electrode to the collector electrode of the transistor 682 via the diode 706, the capacitor 704 and the resistor 698, the transistor 696 being switched to the conductive state. In this case, the capacitor 718 is discharged via the resistor 712 and the transistor 696, so that the grid electrode of the silicone-controlled rectifier 692 is supplied with a current pulse that puts the rectifier into the conductive state, so that the capacitor 688, the inductor 690 and A current flows through the rectifier 692, with the result that energy is stored on the capacitor 688. In order for the energy to be stored sufficiently quickly, the value of the inductor 69O must be selected such that it is no more than approximately 1/5 of the value of the inductor 686. Most of the current from capacitor 688 therefore flows through inductor 690 and not through inductor 686. When capacitor 688 charges to approximately minus 200 volts, the current flowing in inductor 590 is at its maximum. until the energy in the inductor 690 is consumed, with the consequence that

009886/1 5 48

the capacitor is charged to a voltage of approximately -300 volts. This highest voltage depends in part on the ratio of the inductances of inductors 686 and 690 and the losses caused by the resistance in inductor 690 and other circuit elements through which the current flows If the maximum value is reached, and no more current flows in the inductor 690, the silicone-controlled rectifier 692 becomes non-conductive. The capacitor 688 is now discharged into the field-generating inductor 686, a current with a characteristic damped and sinusoidal waveform flowing in the coil, between one end of the inductor 686 and the conductor 678, on which the reference voltage of zero volts is a resistor 691 is turned on with a very small value. The voltage drop across resistor 591 is exactly proportional to the current flowing in inductor 686 and can therefore be used as a synchronization signal for a detector device. In such a device, a detector indicates the presence of a responder if a characteristic signal is determined at a certain time in relation to the time base of the electromagnetic field

The sequence control signal generator 683 has the task of supplying a control signal to the connection points 684A, 684B and 6840 in sequence so that the coils of sections 672A, 672B and 672C generate field pulses, one of which is shown as an inductor 686. The generator 683 could consist of a number of monostable multivibrators in a ring circuit, so that when each multi-vibrator is switched from the unstable to the stable state, the operating states of the following multivibrators in the ring circuit are reversed. The outputs of the individual multivibrators would be fed to connection points 684. Another possibility is to connect the connection points 684 to the individual stages of a simple plip-flop counter, which is operated by a free-running multivibrator

FIG. 13, which consists of two drawings, is a circuit

009886/1548

2 0 3 "'. 3'-, G -fet

forming one of the two and the same Aufb _a u having combinations of Magnetflusstiberwachungseinrichtung 29 to the signal detecting circuits 32 of the plant according to the Fig.1. As can be seen from FIG. 13, the coils 16A, 16B, 16C and 16D of the magnetic flux monitoring device 29 are connected to the input of the detector circuit 32 via a coaxial cable 28.

The detector circuit 32 comprises a signal shaping and amplifying section (SSAS) 128, a signal discriminating section (SDS) 130 and an output section 132, the exit of which via the conductor 134 to the alarm and display device 34 the system according to Fig.1 is directed.

The SSAS section 128 comprises, in turn, an input filter 136, a preamplifier 138 in the first stage, a preamplifier HO in the second stage, a preamplifier in the third stage, which is connected to another filter via a coaxial cable (144) »another amplifier and a limiter stage (148) which switches circuit elements off known designs exist. The two twin T filter elements of the filter 136 have a very high at 60 Hz Transmission impedance on what frequency the frequency of the field generating Device in the embodiment according to Figure 7 is. These filters consist of a cheap version with a tolerance of $ 10, do not require voting, eliminate it almost completely eliminates the very strong 60 Hz interference and attenuates other interference signals up to 1000 Hz as well. In the input filter 136 have capacitors 201, 202, 204 and. 206 a value of 0.01 microfarads, the capacitors 208 and 210 a value of 0.022 microfarads each, the resistors 212, 214 »216 and 218 a value of 270 kilo ohms each and the resistors 220 and 222 a value of 120 kilo ohms each on »In the Yor amplifier stage 138 a transistor with very low self-noise is used, since it should be avoided 'iaea in the amplified signal' at the output an additional self-noise. occurs »

The second and third amplifier stages 140 and 142 cause a signal amplification with good linearity.

009886/1548

ORIQINAL IfSISPECTED

interconnected coupling capacitors attenuate frequencies below about x 1000 Hz. Between the preamplifiers HO and 142, a variable resistor 150 is switched on, with which the system can be set so that no false alarms are triggered are randomly occurring signals that are in the area the system in question may occur frequently. The cheapest Adjustment is made by increasing the alternating voltage applied to the collector electrode of transistor 152 a value at which the detector 130 detects a signal although it is known not to be in the surveillance zone for a responder characteristic signal has been generated 1st. The value of this alternating voltage at the collector electrode is determined, after which the variable resistor 1-50 is set so that the alternating voltage applied to the collector electrode of the transistor 152 half of the determined value.

The filter 144 consists of a high-pass filter with an additional band-pass filter, the mean value of which is matched to the fundamental frequency of the effective field, the latter filter from a twin T-filter network connected between the high-pass filter capacitors. The twin T-filter network has a high transmission impedance at the round frequency of 60 Hz of the effective field, while the high-pass filter capacitors essentially evaporate signals whose frequency is between 60 and 1000 Hz, which frequency is the predetermined frequency in the currently preferred embodiment. In the filter 144, the capacitors 224 and 266 each have a value of 0.01 microfarads, the resistors 228 and 230 each have a value of 270 kilohms, the resistor 232 a value of 120 kilohms and the capacitor 234 a fourth of 0.022 microfarads on. The amplifier 146 effects an additional amplification, while the limiting stage 148 effects a further amplification, represents a high input impedance for the amplifier 146 and supplies the signal discriminator 130 with asymmetrically cut signals.

The signal discriminator 130 generates an output signal which puts the alarm and display device 34 into operation whenever

009886 /: 548 ^: '■■;' ■ "'■'' ^: ORIGINALINSPECTED

if at successive intervals of about 16-2 / 3 Milliseconds three signals with an amplitude at least twice as high as that of the house and with a duration of occur less than about 0.3 milliseconds. Each these signals corresponds to the characteristic signal of a responder of the embodiment described above. Also corresponds to the 16-2 / 3 millisecond interval of the period of a 60 Hz signal and therefore represents the magnetization reversals of a sensitized responder. The signal discriminator 130 is generally synchronized with the effective field in such a way that a characteristic signal is only determined within a time span of approximately 1.5 milliseconds or within a time window that immediately leads to a The change in direction of the field of activity follows. When discovering such a signal is sent to the output section 132 via the Conductor 154 is supplied with a signal. Upon receipt of three signals over conductor 154 at successive intervals of output section 132 carries out the alarm for 16-2 / 3 seconds and display device 34 to a signal. Upon receipt of a first signal, the output section 132 disables the counter during of the following 13-2 / 3 milliseconds, and if no further signal is received in the following 6 milliseconds, so the counter is reset to the KuIl state.

The signal discriminator 130 has a blocking transistor 156 which, together with the trigger circuit 158, the delay timer 160 and the coercive gate 162, causes a Output from the limiter 148 to the combination a waveform shaper 164 and a signal width discriminator 166 prevented for most of each period. In operation, the trigger circuit 158 approximately changes its state at the point in time at which the AC mains voltage exceeds the value zero · At this transition from the positive a negative value takes place at the output of the trigger circuit an equal transition, with a pulse being generated which triggers the delay timer via a capacitor 168 and the monostable multivibrator in the unstable. State offset. The delay timer remains in this state,

009886/1548

20353S6

approximately 4 milliseconds long, after which a shutdown occurs approximately at the point in time in which the field of action has the value zero crossed (the field of action has a lag of slightly less than 90 ° or approximately compared to the mains voltage 4 milliseconds). If the delay timer becomes effective, it conducts a negative-going one through the capacitor 170 Pulse that triggers the coercive gate and puts a monostable multivibrator in the unstable state in which the multivibrator remains approximately 1.5 milliseconds until it returns to the steady state. Lies in the unstable state at resistor 172 a low voltage, so that to the base electrode of the blocking transistor 156 no current flows. When gate 162 is in the unstable state, the transistor is 156 therefore non-conductive, during which time the waveform shaping circuit is put into operation. At the same time, the resistor 174 is supplied with a high voltage, so that the base electrode of transistor 176 receives current and the transistor becomes conductive, with the result that the signal width discriminator is in operation is set. If the multivibrator of the coercive gatexB returns to the stable state, the reverse pail is present. At the Resistor 172 has a high voltage, so that transistor 156 conducts a current through resistor 177 with the result that transistor 179 is continuously conductive, the waveform shaping circuit is taken out of service. At the same time, the resistor 174 is supplied with a low voltage, so that the Transistor 176 receives no power and the signal width discriminator is turned off. Only during the momentary unstable state of the coercive gate 162 in every 60 Hz period a signal can therefore be received. The characteristic signal pulse from a responder according to the invention is generated.

If such a characteristic signal is received by the limiting stage 148 in a timely manner, the state becomes the Waveform shaping circuit changes when the level of amplitude exceeds the value of approximately 8 volts while transistors 179 and 181 switch from normally conducting to non-conducting State. This is done via the condenser

009886/15 4 8 ORIGINAL INSPECTED

sator 178 and the diode 180 passed a pulse that the multivibrator 182 of the signal width discriminator is placed in the unstable state.

The transistors 179 and 181 remain in their new states. So long as the received signal exceeds the value of approximately 6 volts, which is the time for characteristic marker signals is less than about 0.3 milliseconds. Because during this time by the collector electrode 'of the transistor 179 no current flows, the transistor 184 remains blocked, which is blocked again when either one or both transistors 176 and 186 are non-conductive. The non-conductive state of the first transistor has already been mentioned in the description of the coercive gate 162 is described. The transistor 186 is non-conductive during the steady state of the signal width enmultivibrator 182. The transistor 184 is therefore only then conductive when the coercive gate and the signal width multivibrator are in the unstable state and during one Normal state of the signal shaper 164 »when the collector current of transistor 179 supplies its base electrode with a forward bias. The unstable state of the multivibrator 182 must therefore take longer than the width of the characteristic signal.

If the transistor 184 is put into the conductive state by a characteristic signal, the input conductor becomes of output section 132 is fed a negative-going signal via conductor 154.

The output section has a counter 188, a period timer 190, a consecutive pulse gate 192 and a counter clear gate 194.

The period timer 190 is simply a monostable Multivibrator connected to input conductor 154 and moving from a negative going signal into the unstable State is shifted. With every transition of the period timer from the stable to the unstable state, the counter is 188 advanced by the switching transistor 196 by one step. The unstable state of the Perlodenzeitgebera lasts approximately

009 886/15 48 _

IMSPECTbD

2 Π 3 - 3 h 6

13-k! / 3 millieeconds, so the speed of the counter to one counting step every 13-2 / 3 milliseconds or approximately one counting step in a 60 Hz period. The counter will be cleared or reset during these 13-2 / 3 milliseconds lasting time span from the one at connection point 198 Lying forward bias is prevented because in this case the transistor 200 is blocked. That from another monostable Multivibrator existing consecutive pulse gate 192 is in the unstable state when the period timer returns to the stable state. In about 6 milliseconds permanent unstable condition, gate 192 prevents the counter from being reset to zero by ^ j that the base electrode of the counter clear gate 194 is supplied with a bias voltage in the Vorv.ärssinne. Is the period timer has not yet been returned to the unstable state when the consecutive pulse gate 192 has returned to the stable state the counter is reset to the Hull setting.

A relay driver circuit 133 generates when the counter until three has counted, an output signal on conductor 134, which puts the alarm and display device 34 into operation.

The device and the method according to the invention can be used for other purposes besides protecting against theft from libraries or from warehouses. The inputs M eg direction can also be used sum sorting items. The objects belonging to one class can be equipped with a responder whose open strip has a certain AC coercive force, while the objects belonging to another class are blown with a responder whose open strip has a different alternating current coercive force, etc.

The responder according to the invention could also be used as a fraud-proof seal, while maintaining its integrity can be determined without direct contact with facilities, e.g. on a railroad car driving past an inspection point. Such a responder can come from a powerful

009 8 8 6/1548 _0R , _aiNAL inspected

035356

term adhesive consist of a length of an open strip of ferromagnetic material. The adhesive can from that described in American Patent No. * Ee 24 906 Execution, while the open strip " may be made of permalloy 6 mm wide, 25 microns thick and 18 cm long.

Claims

009 886/15 4 8

Claims (1)

Claims Procedure for determining presence, identity or the state of an object in a surveillance zone, characterized in that (1) A responder is attached to the Gregenstand, consisting of at least consists of an open strip of ferromagnetic material, the entire magnetic saturation moment of which is at least 0.1 pole-cm, the magnetization of each strip if this is sinusoidal in the full length of the action of a frequency of 60 Hz changing magnetic test field with a predetermined maximum strength of less than 20 Oersted every change of direction of the test field is reversed so that (2) at least one alternating magnetic field with an amplitude peak of at least 3/4 oersted and at a rate of change of more than 300 oersted per second and is generated in a surveillance zone which is substantially free of frequency components having a frequency of at least 1,000 Hz exceed that (3) an object is introduced into the surveillance zone that (4) all frequency components of the magnetic flux in the surveillance zone within a frequency band with a width above said predetermined frequency monitored by at least 600 Hz and a signal is generated that corresponds to the change in magnetic flux, which is caused by the open strip with every change of direction of the generated field, which signal is determined, and that (5) the amplitude and time characteristic at least one of the signals determined in process stage (4) 009886/154 8 ORIGINALiNSPECTED is used to confirm the presence, identity or condition of the item 2. The method according to claim 1, characterized in that a timing signal is generated in step (5) and with the temporal occurrence of at least one of said signals is compared to the presence, the identity and determine the condition of an object. 3. The method according to claim 1, characterized in that in process step (2) as a field of action sinusoidally changing alternating field is generated. 4. The method according to claim 1, characterized in that in method step (2) at least two magnetic Alternating fields are generated, the frequencies of the alternating fields differ from one another by at least 5 Hz that in method step (4) at least two signals can be determined which correspond to the change in magnetic flux produced by the open strip with each change of direction is caused, and that in method step (5) the amplitude and the time characteristic of at least two Signals is detected to determine the presence, identity and condition of an object. 5. The method according to claim 1, characterized in that a carrier determines an object in the surveillance zone and that method step (2) is only initiated if a carrier has been identified. 6, the method according to claim 1, characterized in that in method step (2) in the monitoring zone a Pulse train with a number of pulses of an electromagnetic field is generated, the lines of all fields, are generally curved, and the corresponding directions of the lines at substantially every point in the Monitoring zone are essentially different from the 009886/1548 Direction of the lines of at least one other electromagnetic field at this point. · 7. The method according to claim 6, characterized in that in method step (2) the pulse sequence during a , Sequence period is generated which has at least one continuous Includes a period of at least 1.0 seconds during which no field is generated and an interval with a duration of not more than 0.4 seconds, in which a pulse is generated. 8. Device for performing the method according to claim 6, characterized by a number of field-generating Means (512 and 530, or 516, 518, 520 and 522 or 528 and 530 or 555, 557 and 559, or 12A, 12B and 14), from which each means generates an electromagnetic field due to the supplied electrical energy, its lines of force are generally curved in a surveillance zone, and their direction at substantially every point in the surveillance zone from the direction of the lines of force at least one further electromagnetic field is different in the named location, and by a device (Fig. 12), which supplies all field-generating means in sequence with electrical energy. 9. Device according to claim 8, characterized in that the field-generating means of first means (512 or 516 and 518 or 528 or 550 or 12A) for generating a first electromagnetic field, and the second Means (514 or 520 and 522 or 530 or 559 or 12B) are provided for generating a second electromagnetic field are whose lines of force are at essentially each 'Position in the surveillance zone essentially vertical to the direction of the lines of force of the first field to the concerned end points. 009886/154 8 OB ^ AL INSPECTED 10. Device according to claim 9 »characterized in that that the first field generating means consists of at least one first long and straight conductor (512 or 528 or 516 and 518 or 574 and 576), and that the second field-generating means consists of at least one further long and straight conductor (514 or 530 or 520 or 594 and 596) that is essentially parallel to the first conductor runs. 11 · Device according to claim 10, characterized in that that the first field-generating means (574 and 576 or and.518) consists of at least two long, straight and parallel Ladders. 12 · Device according to claim 11, characterized in that the second field-generating means consists of at least two long straight and parallel conductors, and that the conductors at least one of the two mentioned field-generating Means consist of parallel sections of a generally rectangular planar loop. 1% device according to claim 12, characterized in that that said loop consists of a generally rectangular coil in the shape of an "8", and that said parallel sections from the end and middle sections consist of the 8-shaped coil 14 · Device according to claim 13 »characterized in that the conductors of the first or the second field-generating By means of parallel sections of a generally rectangular and flat loop, and that the Loops of the two mentioned field-generating means with are located a small distance from each other in substantially parallel planes. 009886/1 BA 8 _QnmmL inspected 5a 15. Device according to claim 9, characterized in that the first field-generating means consists of a first long and straight conductor, and that the second field-generating Means consists of a second long and straight ladder that crosses the first ladder at right angles, whereby the crossing point of the respective ends of the ladder is located away. 16. Device according to claim 15 »characterized in that ■ that of the two mentioned field-generating means at least means comprises at least one additional long and straight parallel conductor extending substantially into is on the same level as the first and second ladder. 17 · Device according to claim 16, characterized in that that of at least one field-generating means alternately one of the conductors with the energy supply device as a first group of conductors is connected, and that the other conductors are connected to the energy supply device as a second group of ladders are connected and that the ■ Energy supply device supplies all named groups with energy in sequence. 18. Device according to claim 15, characterized in that of the first and the second field-generating means at least one means of a central section (574 and 576 or 594 and 596) in the form of an "8" Coil. 19 · Device according to claim 9, characterized in that that the first field generating means (12A) comprises a first, substantially rectilinear electromagnet, and that the second field-generating means (12B) has a second, has substantially rectilinear electromagnets that are close to the first electromagnet and substantially at right angles to this is arranged what electromagnets cross close to their center. 009886/154 8 ORIGINAL INSPECTED 20. Device according to claim 9, characterized in that that the first field-generating means (12A) consists of a substantially rectilinear electromagnet, that the second field-generating means (14) consists of a substantially planar air-core coil, the diameter of which is approximately the same the distance between the magnetic poles of the first electromagnet and that the air core is close to the electromagnet is arranged so that its circumference is in the vicinity of the poles of the electromagnet. 21 · Device according to claim 9 »characterized by a third means (590 or H) for generating a third electromagnetic field, the field lines of which run in one direction at essentially every point in the monitoring zone essentially perpendicular to the directions of the field lines of the first and the second field get lost. Device according to Claim 21, characterized in that both the first (550) and the third (590) field-generating means consist of a generally rectangular and figure-8-shaped coil, the turns of which form two generally rectangular coil parts of almost the same size each coil portion has substantially parallel upper and lower lengths, with an upper and a lower length together forming a central portion of the "8" coil, while the other upper and lower lengths of the coil portions form end portions of the ^H 8 "coil which is ^M 8 ^M coil is oriented in such a way that its central sections cross each other at right angles close to its centers, that the second field-generating means (570) consists of parallel sections of a generally rectangular ⁿ o "coil, that the ^H 8 ^M coil and the ^M o ^H coil are closely spaced from one another in substantially parallel planes, and that all parallel sections of the ^w o ^M coil are between the middle section and one end section of the ^H 8 "coil run parallel to them, 009886/154 8 2035358 23 set-up length according to claim 22, characterized in that dasβ identifies the mentioned energy supply device a source of electrical energy, an energy transfer section interposed between each field generating means and the Energy source is switched on that every energy transmission section contains a switch which, based on a control signal, causes the transmission section to open a To conduct energy pulse from the energy source to the field-generating means, and that a control signal generator is provided which supplies a control signal to all switches in a predetermined order. 24. Device according to claim 23 »characterized in that that each field generating means consists of a coil with a substantial electrical inductance that said Energy source consists of a direct current source, and that each energy transmission section has a capacitor has that the energy transfer section forms an LC circuit together with the field-generating means, that the capacitor of the transmission section stores an energy pulse when said switch is actuated and the energy as a damped energy impulse to the field generating one Funds. 25 · Device according to claim 24, characterized in that that said LC circuit consists of an overdamped electrical circuit, which is an overdamped electromagnetic Field pulse generated. 26, device according to claim 24, characterized in that that the IC circuit consists of an underdamped electrical en
There is a circuit that generates an underdamped electromagnetic field pulse. 009886/154 27 · Device for carrying out the method according to claim 1, characterized by an open strip of a thin and flat ferromagnetic tape with a thickness from about 0.1 to 150 microns or from a ferromagnetic Wire approximately 10 to 300 microns in diameter, and characterized in that said open strip has the ratio of length to the square root of Cross-section is at least 150. 28. Device for performing the method according to claim 1, indicated by an open strip a thin flat disk made of a ferromagnetic Material approximately 0.1 to 130 microns thick, and characterized in that the ratio of major diameter to thickness of the disc is at least 6,000. 29. Device for performing the method according to claim 1, characterized by a responder, consisting of ^H n ^M open strips, where ^M n ^{w is} an integer greater than 1, which said strips are chosen so that they are after a change in direction of the field of action reverse their magnetization in sequence in equal time intervals, each time interval being equal or smaller than 7 £, where ^W T ^{M is} equal to the period of the effective field, and with each reversal of magnetization a magnetic pulse is generated which occurs with a characteristic frequency that can be clearly determined by a simple device. 30. Device for performing the method according to claim 1, characterized in that the responder from a layer of a normally tacky, very strong self-adhesive and at least one of the adhesive on one side there is an open strip that carries a peelable backing material on the adhesive layer is attached, eo that the open strip after removal of the carrier material with the help of the adhesive layer can be attached to an object. 009886/154 8 31. Device for performing the method according to claim 1, characterized in that the responder also has at least one control element made of a ferromagnetic Has material, the coercive force of which is at least 5 Oersted, and which has a remanent magnetization static external »magnetic field of at least 3/4 oersted generated on part of the open strip, this being is at least partially magnetized, the amplitude and the time characteristic of a signal generated by the open strip under the action of the effective field clearly different from the corresponding signal when the control element is demagnetized 32 · Device according to claim 31, characterized in that that each control creates a static external magnetic field on a different part of the open strip. 33 · Device according to claim 32, characterized in that the control elements have different coercive forces exhibit. 34 · Device according to claim 31, characterized in that the control element over the entire length of the open A static external magnetic field with a value of at least 3/4 Oersted is generated across the strip. 35 · Device according to claim 7, characterized by a Number of field generating agents, each of which is agent Generates an electromagnetic PeId in a surveillance zone, the field lines of which are generally curved and on one at essentially every location in the surveillance zone have a different sighting than the field lines of at least one further electromagnetic field on the relevant Provided by facilities that change the magnetic flux above 1,000 Hz within the surveillance zone components and an external polar magnetic field beeper determine that is generated by a responder when the direction of the field of action changes, by means that 0098 86/154 8 - 5f- St. due to the determination of an external polar magnetic field generate a status display, and by means of preventing a responder from changing the direction of the Effective field generates an external polar magnetic field pulse 36 · Device according to claim 35 »characterized by identifiers which are assigned to each object and can be read by an appropriate device, by means of encrypting and recording a label, and by means based on the reading of the Identity card of a user and a token one Activate the desensitization device and record the contents of the identity card and the number plate 37 device for carrying out the method according to claim 1, characterized by an electrical circuit, which generates a damped, sinusoidal electromagnetic field in a surveillance zone, which activates a responder passed through the surveillance zone an electrical energy absorbing resonance circuit with an inductive and a capacitive component, which two components are connected in parallel, the inductive component consisting of a conductor which generates an electromagnetic field, and a device which connects a source of electrical energy to the resonant circuit, whereby a predetermined amount of electrical energy, energy is transmitted to the resonance circuit, and a damped sinusoidal in the monitoring zone due to the consumption of the remaining transmitted energy in the resonance circuit when the energy source is switched off from the resonance circuit electromagnetic field is generated, the intensity of which is sufficient to activate a responder. 38. Device according to claim 37 »characterized by a with the resonance circuit and the connecting device in Series switched inductor ÖWßSWAL INSPECTED 009886/1548 39. Device according to claim 37, characterized by a Inductor, which consists of the primary winding of a transformer, while the inductive component is the secondary winding of a transformer. 40. Device according to claim 38, characterized in that that the inductance of the inductive component is 4.7 to 25 times the inductance of the inductor is that of the connecting Set up a trigger circuit and a silicone-controlled rectifier with an anode conductor, a Has cathode conductor and a grid conductor, which rectifier on the anode and cathode conductor between the energy source and the inductor are connected, that the trigger circuit is connected to the grid conductor of the silicone-controlled rectifier and this is a bias voltage in a forward sense when a control signal is used to transfer electrical energy through the inductor to the Resonant circuit causes until the flow of current in the inductor is essentially stopped, after which the silicone-controlled Rectifier no longer conducts and switches off the energy source from the resonance circuit. 41 · Device according to claim 40, characterized in that that the inductance of the inductive component is approximately six times the inductance of the inductor. 42. Device according to claim 39, characterized in that that the transformer consists of an autotransformer (autotransformer). 43. Device according to claim 37, characterized by one with the connecting device and the resonance circuit in ; Series switched resistor. 44 · Device for generating a damped sinusoidal electromagnetic field in a monitoring zone to activate a through the monitoring zone ί i: ■ C 0 09886/1548 - 50. - led responders, characterized by a resonance circuit to absorb electrical energy with an inductive component and with a capacitive component connected in parallel to it Component, wherein the inductive component consists of a conductor, which as a result of a flowing through the conductor Electricity generates an electromagnetic field, and through a device that intermittently provides a source of electrical Energy connects with the resonance circuit until the extent of the dissipation of the energy from the resonance circuit exceeds the extent to which the energy is stored by the resonant circuit, after which the remaining electrical energy consumed in the resonance circuit as a damped sinusoidal current in the conductor and a corresponding damped sinusoidal electromagnetic field is generated. 009886/154 8 to Blank page