EP1266352A2

EP1266352A2 - Marking device, method and apparatus for the production thereof and a method for reading a marking device of this type

Info

Publication number: EP1266352A2
Application number: EP01915131A
Authority: EP
Inventors: Wolfgang Eberhardt; Jan Morenzin; Daniel Schondelmaier
Original assignee: Forschungszentrum Juelich GmbH
Current assignee: Forschungszentrum Juelich GmbH
Priority date: 2000-02-22
Filing date: 2001-01-10
Publication date: 2002-12-18
Also published as: US20030091867A1; AU2001235407A1; WO2001063554A3; DE50115032D1; WO2001063552A2; ATE439648T1; WO2001063554A2; EP1257968A2; US7055758B2; WO2001063553A2; WO2001063552A3; US20030118719A1; AR027462A1; WO2001063553A3; US20030107832A1; DE10008097A1; AU2001225147A1; AR027463A1; AU2001242330A1; EP1266351A2

Abstract

The invention relates to a marking device (21) for the identification of objects, comprising a coding consisting of areas (24, 25) of differing magnetic properties. The marking device is characterised in that it has magnetic areas (24, 25) consisting of a homogeneous, ferromagnetic or ferrimagnetic material, each of said areas having a magnetic anisotropy with an easy and hard magnetic axis, whereby areas with a different orientation of the easy magnetic axis and/or areas with remanence of different strengths succeed each other in at least one specific direction. The invention also relates to a method for producing a marking device of this type and to apparatus for carrying out the method.

Description

Description;

Marking device, method and device for their production and method for reading out such a marking device

The invention relates to a marking device for the identification of objects, with a coding from areas with different magnetic properties, method and device for their production, and a method for reading out such a marking device.

Magnetic encodings are often used for marking and thus individual assignment and securing of credit cards, credit cards, access cards, electronic keys or the like, often in the form of a so-called magnetic strip. A permanent magnetic layer is selected for the coding, i.e. magnetized in areas such that areas of different magnetization arise, and in the sense of the present description unmagnetized areas, that is to say those with zero magnetization, also belong. With appropriate magnetic field sensors, the magnetic signature or coding can be detected and then processed according to the respective purpose.

Numerous different proposals for the formation of magnetic stripes have been made. In the US Pat. No. 4,650,978 uses the natural random variations in the magnetic properties of the magnetic strip, caused by the variations in coercivity, granularity, layer thickness, surface profile and in particular by random variations in the hysteresis loop and its past magnetic history. A similar procedure is used for coding according to US 5,616,904 and US 4,837,426. The magnetic structure is digitized in a suitable form and used to identify the objects. A disadvantage is that the magnetic strips can be manipulated relatively easily and are not resistant to external magnetic fields.

US Pat. Nos. 5,480,685 and 5,972,438 describe magnetic strips in which magnetic particles are embedded in a binder matrix, the magnetic strips each having two layers of different coercivity. In the magnetic strip according to US Pat. No. 5,177,344, magnetic particles are also present within a binder matrix, the magnetic particles being influenced by the application of an external magnetic field in such a way that they produce magnetic areas of different characteristics. This type of magnetic stripe has the disadvantage that the magnetic structure can be changed subsequently by heating the binder and then realigning the magnetic particles by external magnetic fields. In the magnetic stripe according to US Pat. No. 5,365,586, a multiplicity of microcrystalline structures are arranged in a random grid. The magnetic stripe is then subjected to saturation magnetization, the remnant noise being read out and used for identification. This magnetic stripe can also be influenced by external manipulation.

In US Pat. No. 5,254,843, the random variations in the chronological sequence of the flow changes that occur when writing conventional magnetic tapes and strips are used and used to identify the respective object. Here, too, the random structure is easy to reproduce when it is known. In addition, the method requires a randomness of the temporal variations, which is not absolutely necessary, particularly in the case of typing.

In the not previously published PCT / EP 99/08433, a marking device is proposed in which the coding has a magnetic base layer and a magnetic coding layer, which cooperate in such a way that areas with non-parallel or anti-parallel magnetic coupling result from the extension of the base layer and coding layer. The effect of the magnetic interlayer coupling is used. The marking device has the advantage of a very characteristic behavior which deviates from the usual magnetic markings when external magnetic fields are applied, which is particularly evident in that although the non-parallel or anti-parallel coupling breaks up under the influence of a saturation magnetic field, the original magnetization is restored after removal of the external magnetic field. The coding cannot therefore be deleted by external magnetic fields. In addition, the effect can be used, for example, to reactivate weakened or even lost magnetic codes due to longer storage times by exposing them to a saturation magnetic field.

The invention has for its object to design a marking device of the type mentioned so that the coding is permanent, difficult to manipulate and insensitive to external influences. It should also make it possible to carry out an authenticity check without a data connection to an external computer. Another object is to provide methods and devices for the manufacture of such marking devices.

The first part of the above-mentioned object is achieved according to the invention in that magnetic regions made of a homogeneous, ferromagnetic or ferrimagnetic material are present, each of which has a magnetic anisotropy with a magnetically easy and hard axis, in at least one specific direction - this is then the intended reading direction - areas with different directions of the easy axes and / or areas with remanence of different strengths derfolgen. The basic idea is to provide a spatial distribution of the magnetic anisotropy, each with a magnetically light and hard axis. Such anisotropy is also referred to as bidirectional anisotropy. It is insensitive to external influences if the ferromagnetic or ferrimagnetic material has a Curie temperature far above room temperature - preferably above 150 ° C - as is the case with the ferromagnetic materials Co or NiFe. Homogeneous materials are understood to mean both elemental substances and alloys or chemical compounds of such substances as oxides, provided that they are constant over the length of the coding - apart from any given crystallinity - which are not, for example, matrix systems or the like.

The marking device is expediently present in such a way that the magnetic areas adjoin one another directly in the specific direction. However, this does not rule out that the magnetic areas are also spaced apart in the specific direction, the areas between the magnetic areas not being able to be made magnetizable.

In the case of the invention, it is advantageous if the magnetic regions have saturation magnetizations of the same size. When an external magnetic field is applied to the coding up to the saturation range, a homogeneous magnetization over the extension then arises the coding, which forms a reference and enables an authenticity test. It is understood, however, that this is not a mandatory requirement, since the saturation magnetization can also vary over the extent of the coding. If this variation is saved, the authenticity test can be used to determine whether there has been manipulation or not. The coding as such is stored in the distribution of the magnetic bias or the anisotropy.

The marking device according to the invention can be produced in that a coding layer made of a homogeneous, ferromagnetic or ferrimagnetic material is applied to a carrier and that areas with magnetic anisotropy with a magnetically light and hard axis are produced in such a way that areas in at least one specific direction with different directions of the easy axes and / or areas with remanences of different strengths follow one another. This can be done in such a way that the magnetic areas directly adjoin one another in the specific direction and / or are spaced apart.

Since the coding layer can be made relatively thin, it is advisable to use vapor deposition technology for the layer structure, that is to say to use thermal vapor deposition, sputtering or the like. The coding layer should then be covered by a protective layer, for example made of DIC (diamond like carbon) or you, which is preferably also applied by vapor deposition.

The magnetic anisotropy can be impressed in a simple manner by applying an inhomogeneous magnetic field to the coding layer during layer construction. The distribution of the inhomogeneity of this magnetic field causes a pattern of different magnetic anisotropy to arise and allows the coding layer to be applied with a uniform layer thickness.

The magnetic field can be generated, for example, by inhomogeneously magnetizing a magnetizable carrier or a magnetizable base for the carrier. In the latter case, the support is placed on this support and the coding layer is built up on the combination of support and support.

The marking device can be produced particularly economically if a carrier film is withdrawn from a supply and brought together with a continuously moving magnetic film and both are passed through a coating station in which the coding layer is applied. Then the carrier film and magnetic film should be separated again. It is expedient that the magnetic film is also removed from a supply and then magnetized and taken up again in a memory after the coating station. It is particularly advantageous if the magnetic film circulates through the Coating station is performed. In order to produce a changing inhomogeneity of the magnetic field, the magnetic film should be magnetized individually in front of the coating station and demagnetized again after the coating station, or its magnetization should be homogenized.

Instead of a magnetic foil, the magnetic field can also be built up by means of coils generating magnetic fields.

A device for carrying out the method described above is characterized by

a) a storage for a carrier film;

b) a coating station for building up the coding layer;

c) a magnetic field device assigned to at least the coating station for generating an inhomogeneous magnetic field over the surface of the carrier film;

d) a recording memory for recording the marking device;

e) guide devices and a drive for guiding the carrier film from the storage unit through the coating station to the storage unit. In this device it can be provided that the magnetic field device is arranged in front of the coating station and that a magnetizable carrier film is guided through it. Instead, the magnetic field device can have a magnetic film which is magnetized inhomogeneously, the guide devices bringing the carrier film and magnetic film together in front of the coating station. Specifically, this can be done in that a storage memory for the magnetic film is provided in front of the coating station and a storage memory of the coating station and the magnetic field device has a magnetizing device which is arranged between the storage memory and the coating station.

Alternatively, however, the magnetic film can also be endless and can be guided through the coating station together with the carrier film via the guide devices. Expediently, the magnetic field device should then have a magnetizing device, seen in the direction of travel of the carrier film, in front of the coating station, which generates an inhomogeneous magnetic field, and a quenching device should be provided for demagnetizing or homogenizing the magnetic field between the coating station and the magnetizing device. The magnetic film can be stretched, for example, on a support roller which is assigned to the coating station and over which the carrier film runs. Instead, however, the roll shell itself can also be designed to be magnetizable, with a magnetizing device for magnetizing the roll shell and a soldering device Shearing device for demagnetizing or homogenizing the magnetic field can be provided. The roll shell can also be provided with a magnetizable coating. In all cases, the quenching device and the magnetizing device should be arranged one after the other in the direction of rotation of the support roller in the region of the roller shell which is free of the carrier film.

Deviating from this, it is provided that the magnetic field device has a plurality of magnetic field-generating coils. These coils can be arranged in the region of the surface of a carrier roller, over the roller jacket of which the carrier film is guided through the coating station, so that an inhomogeneous magnetic field prevails during the vapor deposition.

According to a further feature of the invention, it is provided that at least the coating station is assigned a heating device for generating a homogeneous temperature field, preferably above the Curie temperature.

It is also proposed that a further coating station is provided for applying a protective layer to the coding layer. It is expedient if the coating stations have vapor deposition devices in order to bring about the application of the coding layer by means of thermal vapor deposition or sputtering. The storage device or storage device can advantageously be designed as supply rolls or storage rolls. The method according to the invention can also be designed in such a way that the magnetic regions are built up with a direction of evaporation which is oblique to the surface of the carrier, at least two different directions of evaporation being used with respect to the plane of the carrier. This alone allows the anisotropy distribution according to the invention to be effected with different directions of the easy axes. However, this effect can also be enhanced by simultaneously impressing an expediently inhomogeneous magnetic field, which is in each case rectified to the vapor deposition devices.

Specifically, the aforementioned method can be carried out by covering areas of the carrier with a first mask when vapor deposition in a first vapor deposition direction, and that at least the areas of the substrate that have been vapor-deposited with the first vapor deposition device are vapor-deposited in a second vapor deposition direction a second mask can be covered. The first and second vapor deposition devices can also be identical if they have devices by means of which the vapor deposition direction can be changed. There is the possibility that areas that have not previously been vaporized are also covered with the second mask when vapor deposition in the second direction of evaporation and at least some of these areas are vaporized in a third vapor deposition device after removal of this second mask and application of a third mask. In order to be able to manufacture the marking device in a continuous process, it is provided according to the invention that a carrier film and at least two mask films are each withdrawn from a supply and the carrier film and one of the mask films are brought together before each vapor deposition and then the vapor deposition takes place from the side of the mask film and the mask film is separated again from the carrier film before the carrier film is brought together with another mask film. In this case, the mask film can be provided with a specific mask pattern even before it is withdrawn from the supply. As an alternative to this, it is proposed that the masking film be provided with recesses only after deduction from the supply, but before being brought together with the carrier film.

A device for performing the method is characterized by

a) a storage for a carrier film;

b) several coating stations for vapor deposition of the carrier film in different vapor deposition directions;

c) a number of storage memories for mask foils corresponding to the number of coating stations;

d) recording memory for the recording of the mask foils; e) a recording memory for recording the marking device;

f) guiding devices and a drive for guiding the carrier film from the supply store through the coating stations to the receiving memory and for merging the carrier film with a mask film in front of a coating station and for separating the carrier film and mask film after a coating station.

Each coating station is expediently assigned a storage memory for a mask film and a storage memory for holding the mask film. In this case, a mask formation station for forming recesses in the mask film can be arranged in each case between the storage memory for the mask film and the combination of mask film and carrier film, in order to impress an individual mask pattern on the mask film. The mask formation station can have, for example, a laser burning device which has a control device for variable location control.

In this device too, a further coating station can be provided for applying a protective layer to the coding layer. The storage devices are expediently designed as supply rolls and the storage devices as storage rolls. The coating stations should preferably have carrier rollers. sen, the carrier film and the mask film are guided over the roll shell.

The method according to the invention can also be carried out by first building up a layer and magnetizing this layer during or afterwards in such a way that it has a homogeneous anisotropy direction, and then the layer

a) a homogeneous magnetic field and an inhomogeneous temperature field or

b) an inhomogeneous magnetic field and a homogeneous temperature field or

c) an inhomogeneous magnetic and temperature field

is exposed, the temperature being above the Curie temperature of the layer. By heating the homogeneously magnetized layer to a temperature above the Curie temperature, the distribution of the different magnetic anisotropy can be controlled in that either the temperature field is made inhomogeneous under the simultaneous action of a magnetic field, the magnetic field can be homogeneous or inhomogeneous, or that an inhomogeneous magnetic field acts at a homogeneous temperature field.

To build up the magnetic field both in the layer structure and in the subsequent temperature application a magnetizable carrier can be provided which is magnetized accordingly. Instead, a magnetizable base can also be provided, which magnetizes correspondingly homogeneously or inhomogeneously and the carrier with the layer is placed on this base. If the magnetic field is imprinted after the layer build-up, the combination of base and carrier can then be exposed to the temperature field.

In order that the process can be carried out continuously, a carrier film should be pulled from a supply and brought together with a continuously moving magnetic film and both should be passed through a heating station, after which they are also separated again. The magnetic film can also be removed from a supply and then magnetized and stored in a memory after the heating station. Alternatively, it can be provided that the magnetic film is circulated through the heating station, the magnetic film being magnetized in front of the heating station and either demagnetized after the heating station or its magnetization being homogenized. The latter is particularly expedient if the carrier film is to be exposed to an inhomogeneous magnetic field.

A device for performing this method is characterized according to the invention by

a) a storage for a carrier film; b) a treatment station with magnetizing device and heating device;

c) a recording memory for recording the marking device;

d) guide devices and a drive for guiding the carrier film from the storage device through the treatment station to the storage device.

With the aid of this device, inhomogeneous or homogeneous magnetization and / or inhomogeneous or homogeneous temperature control can be carried out in the treatment station in accordance with the method provided for this purpose. This was preceded by the application of a homogeneous, ferromagnetic or ferrimagnetic layer with a homogeneous alignment of the bidirectional anisotropy on the carrier film. This is expediently done in a single device, in that the device described above is supplemented by the following device parts:

a) a coating station for applying a layer with a homogeneous anisotropy direction to the carrier film;

b) guide devices and a drive for guiding the carrier film from the supply store through the coating station and the treatment station to the receiving store. The coating station is provided with a device for generating a sufficiently strong homogeneous magnetic field which defines the direction of the magnetic anisotropy. The device can be designed in such a way that a magnetic field which is sufficiently large for the realignment of the magnetic anisotropy is brought about directly above the carrier film between the coating station and carrier film and at the point where the material strikes the carrier film.

In this case, too, a magnetic field can be applied with the aid of a magnetic film which is magnetized in a correspondingly homogeneous or inhomogeneous manner, the guide devices bringing the carrier film and magnetic film together in front of the treatment station. Specifically, this can be done in that a storage memory for the magnetic film is provided in front of the treatment station and a storage memory after the treatment station and in that the magnetizing device is arranged between the storage device and the heating device.

Instead, the magnetic film can also be endless and can be guided together with the carrier film through the heating device via the guide devices. If an inhomogeneous magnetic field is to be generated, the magnetizing device should be arranged in front of the heating device, as seen in the direction of travel of the carrier film, and an extinguishing device for demagnetizing or homogenizing the magnetic field between the heating device and magnetizing device can be provided. The magnetic film can be freely guided over deflection rollers. However, it can also be clamped onto a support roller which is assigned to the treatment station. In this case, however, an additional magnetic film can be dispensed with if the roller shell is designed to be magnetizable or has a magnetizable coating. The extinguishing device and the magnetizing device are expediently arranged one after the other in the direction of rotation of the support roller in the region of the support roller which is free of the carrier film.

Depending on the type of process, the treatment station can have heating devices for locally heating the carrier film, lasers being particularly suitable for this. In this case, a homogeneous magnetic field generated by an appropriate magnetizing device is sufficient. Alternatively, the treatment station can have a heating device for generating a homogeneous temperature field and a magnetizing device for generating an inhomogeneous magnetic field.

A homogeneously magnetized layer in the sense of the present invention can be changed not only by subsequent exposure to a magnetic and temperature field, but also by local ion bombardment in such a way that there is a change in the direction of the anisotropy and / or the Remanence is coming. The ion bombardment can take place with the aid of a focused ion beam. Alternatively, it is provided that the ion bombardment takes place over a wide area and an inhomogeneous electric charge field is generated in the region of the carrier.

This can be done in such a way that an electrically chargeable carrier is charged inhomogeneously before the ion bombardment. The electrical charging can take place, for example, with the aid of an inhomogeneously electrically charged base, in that the carrier is placed on this base.

The carrier film is expediently drawn off from a supply and, after coating, brought together as a base with a continuously moving charge film. Both are then subjected to extensive ion bombardment. Then they are separated again. The charge film can also be removed from a supply and then charged and stored in a memory after ion bombardment.

In a departure from this, the charge film can also be circulated through an ion bombardment station and the charge film can be charged in front of the ion bombardment station and discharged again after the ion bombardment station, or the electrical charge can be homogenized. In this way, a charge pattern can be individually stamped on.

As an alternative to this, it is proposed that a carrier film and a mask film are continuously supplied from one supply each are withdrawn and brought together and that the ion bombardment then takes place from the side of the masking film and the masking film is separated again from the carrier film. In this case, the mask film should be provided with recesses after deduction from the supply and before being brought together with the carrier film. However, it can also be provided that a masking film provided with recesses is already kept in stock.

The device can be designed analogously to the device in which a treatment station with a magnetizing device and heating device is provided. Instead of this treatment station, an ion bombardment station is now provided for the ion beam exposure to the layer located on the carrier film. With the help of the ion bombardment station, a focused ion beam can be generated, with a control device cooperating to control the ion beam in a targeted manner. Inhomogeneous ion beam exposure can also be generated with a flat ion beam if it strikes an inhomogeneous charge field in the area of the carrier film with areas that have a charge corresponding to the charge of the ions and accordingly repel the ion beam in these areas, i.e. not on the carrier film let hit.

The latter can be achieved, for example, in that an electrically chargeable carrier film is guided through the ion bombardment station and is passed over a charging device with an inhomogeneous electric charge is provided. As an alternative to this, it is provided that an electrically chargeable charge foil, which is provided with an inhomogeneous electrical charge, is passed through the ion bombardment station and that the guiding devices bring the carrier foil and charge foil together in front of the ion bombardment station. A storage store for the charge film in front of the ion bombardment station and a storage store after the ion bombardment station and a charging device for inhomogeneous charging of the charge film can be arranged between the store and ion bombardment station. Instead, the charge film can also be endless and can be guided together with the carrier film through the ion bombardment station via the guide devices. In this case, the charging device, viewed in the direction of travel of the carrier film, is provided in front of the ion bombardment station and a quenching device for discharging or homogenizing the electrical charge between the ion bombardment station and the charging device. The charge film can also be clamped onto a support roller which is assigned to the ion bombardment station.

In the latter case, a charge film can be dispensed with if the roll shell of the backup roll can be charged with electrical charge. Then a charging device for charging the roll shell and an extinguishing device for discharging or homogenizing the electrical charge of the roll shell should be provided. So that the roll shell can be electrically charged, it can also be provided with a corresponding coating. The unloading device and the charging device are expediently arranged one after the other in the direction of rotation of the support roller in the region of the support roller which is free of the carrier film.

Alternatively, it can be provided that a mask film is guided through the ion bombardment station and that the guide device bring together the carrier film and mask film in front of the ion bombardment station in such a way that the ion bombardment takes place from the side of the mask film, and that the guide devices follow the carrier film and mask film disconnect the ion bombardment station. In this case too, the ion bombardment can take place over a wide area, the exposure to the layer on the carrier film being limited to the recesses in the mask film.

A preformed mask film can already be introduced into the device. Alternatively, it is proposed according to the invention that. A mask formation station for forming recesses in the mask film is arranged between a storage reservoir for the mask film and the combination of mask film and carrier film, the mask formation station being provided as a laser burning device with a control device for variable local control.

The invention further relates to a method for reading out the marking devices described above with the aid of at least one magnetic field sensor. He- According to the invention, the coding is subjected to at least two readout processes, a readout process in a zero field and a readout process in an external magnetic field, or the readout processes in different magnetic fields. In the first-mentioned reading process, the information stored in the magnetic areas is recorded in a spatially resolved manner, for example by reading out certain features of the hysteresis loop. In the second readout process, which is preferably carried out with saturation magnetization, the distribution of the saturation magnetization is recorded and compared with a predefined reference structure. The order of the two reading processes is not important.

It is also advantageous that conventional magnetic field sensors are suitable for reading out the marking devices according to the invention, i.e. For example, inductive, magneto-resistive, magneto-optical, Hall or SQUID sensors can be used. The spatially resolved reading takes place by relative movement between the magnetic field sensor and the marking device, it being irrelevant whether only one of them or both are moved. A plurality of magnetic field sensors can also be used in order to detect the magnetic structure of the marking device in a spatially resolved state in the idle state.

Various features of the hysteresis loop can be used to determine the information stored in the coding. The remanence in one is easy to grasp Zero field or a very small magnetic field. Instead, however, there is also the possibility of detecting the flow change at the boundaries of two areas, since stray fields arise at the boundaries of the marking device according to the invention, the distribution of which in a certain direction forms the coding.

In the drawing, the invention is illustrated in more detail using exemplary embodiments. Show it:

Figure 1 is a plan view of part of a marking device in remanence showing the hysteresis loops of two magnetic areas;

Figure 2 shows a longitudinal section through the marking device according to Figure 1 and

3 shows a schematic diagram of the marking device according to FIGS. 1 and 2 with a magnetic field sensor.

FIG. 4 shows the principle for the production of an inhomogeneous magnetic field by means of a magnetizable base;

FIG. 5 shows a device for producing a marking device by means of layer construction in an inhomogeneous magnetic field; FIG. 6 shows a device for producing a marking device by means of oblique evaporation in two directions of evaporation;

Figure 7 shows a device for producing a marking film by means of ion bombardment.

A marking device 21 is shown in FIGS. 1 and 2, in which a homogeneous, ferromagnetic layer 23 is applied to a carrier 22. The ferromagnetic layer 23, for example made of Fe, Co, Ni, a magnetic rare earth metal, an alloy or a ferrite of the same, is composed of randomly arranged and formed and distributed over the surface magnetic areas - for example designated 24 or 25. In the manufacture of the ferromagnetic layer 23, a magnetic anisotropy has been generated by appropriate local field application in such a way that in the magnetic regions 24, 25 the easy axis is aligned according to the arrows (symbolized in FIG. 2 by the point in a circle).

If a measurement is carried out with a magnetic field sensor in the direction indicated by the arrow below the carrier 22 (FIG. 2), ie the readout direction, the magnetic areas 24 show a magnetic behavior corresponding to the hysteresis loop 26, while the magnetic areas 25 show a magnetic behavior corresponding to the Have hysteresis loop 27. At the transitions conditions between two adjacent areas 24, 25 there are differences in the strength of the remanent magnetization with respect to a readout direction. The flux changes that occur there generate stray fields which, like the local magnetization themselves, structure a signal curve which corresponds to the coding.

When an external magnetic field is applied in the saturation region, magnetization is uniform in the direction of the magnetic field H. After the magnetic field has been removed, the structure shown is created again.

In Figure 3, the marking device 21 is shown upside down, so that the carrier 22 is on the top and the ferromagnetic layer 23 on the bottom. Underneath is a magnetic field sensor 31, which has a reading head 32, to which the marking device 21 with the carrier 22 is guided in the pulling direction. A stray field is generated at the boundaries of the regions magnetized differently in the zero field, which induces a current pulse 33. Via an external current source 34, an additional current can be fed into a coil 35 on the read head 32, whereby an external magnetic field is generated at the location of the detection. The signal resulting from reading is processed in an amplification stage 37 and in a further stage 38. If the external current is zero, the stored information can be read. Is the current sufficient to saturate the ferromagnetic layer 23 gen, the current pulses 33 disappear. An authenticity check of the coding is thus possible.

It is particularly advantageous if the magnetic field sensor 31 and the ferromagnetic layer 23 are matched to one another in such a way that the saturation field corresponds to a field strength at which the characteristic of the magnetic field sensor 31 is linear in order to distinguish between saturation of the coding and saturation of the magnetic field sensor 31 can. Another way to avoid the saturation problem of some magnetic field sensors, e.g. inductive or magnetoresistive magnetic field sensors, it is to apply the saturation field in a direction that does not correspond to the sensitive area of the magnetic field sensor. It is also advantageous to use a magnetic field sensor that is suitable for detecting the local magnetization of the layer (e.g. magneto-optical reading devices), so that an influence of the external field on the sensitivity of the magnetic field sensor can be excluded.

FIG. 4 shows a carrier plate 41 on which a magnetic film 42 is placed. The magnetic foil 42 is magnetized perpendicularly to the layer plane in strips - designated 43 by way of example - in one strip 43 with a preferred direction downwards and in the adjacent strip 43 with a preferred direction upwards, which is symbolized by the arrows. This results in a stray field configuration, as is illustrated schematically by the semicircles 44. That so The stray field formed is sufficient to determine the direction of the magnetic anisotropy.

A carrier film 45 is placed on the magnetic film 42, via which a magnetic field distribution is generated by the magnetic film 42, the components of which vary in the layer plane in accordance with the underlying pattern, which is represented by the horizontal arrows on the carrier film 45. When a suitable ferromagnetic or ferrimagnetic material is evaporated onto the carrier film 45, the magnetic field distribution determines the spatial distribution of the magnetic anisotropy and thus the signature of the coding.

FIG. 5 shows a device 46 in which the principle shown in FIG. 4 is applied in a continuous manufacturing process. The device 46 is located in a housing, not shown here, which is under high vacuum.

The device 46 has two steaming stations 47, 48, with each steaming station 47, 48 being assigned a support roller 49, 50 which are flanked in the lower area by deflection rollers 51, 52 and 53, 54, respectively.

The first steaming station 47 is provided with a steaming device 55 above the associated support roller 49. The support roller 49 is provided on its roller shell with a magnetic layer 58, for example an approximately 3 mm thin polymer layer, into which a high proportion of romagnetic particles is embedded. Below the support roller 49 and between the associated deflecting rollers 51, 52, a magnetizing device 59 is provided on the left-hand side, which has a series of permanent magnets and / or magnetic field-generating coils and is able to provide the magnetic layer 58 with a specific magnetization pattern, the simplest in FIG the form shown in Figure 4. The magnetic layer 58 thereby generates an inhomogeneous magnetic field corresponding to its magnetization. To the right of the magnetizing device 59 there is a quenching device 60 which either completely demagnetizes the magnetic layer 58 or magnetizes it homogeneously and thus eliminates the inhomogeneous magnetization previously impressed by the magnetizing device 59.

A carrier film 62, for example a polyester film, is rolled up on a supply roll 61. In operation, the carrier film 62 is pulled off the supply roll 61 by driving the support rollers 49, 50 and rotates around the first deflection roller 51 and thus reaches the magnetic layer 58, where it is carried along by the rotation of the support roller 49. In the vapor deposition device 55, the carrier film 62 receives a layer 63 made of a ferromagnetic material. The desired directional distribution of the magnetic anisotropy is generated by the spatial magnetic field distribution, caused by the magnetic layer 58.

After running around the deflection rollers 52, 53, the carrier film 62 reaches the second vapor deposition station 48, where it opens the circumference of the associated support roller 50 runs up and rotates with the support roller 50. It passes through a vapor deposition device 64, with which a protective layer 65 made of z. B. DLC is applied. After passing through the second evaporation station 48, the carrier film 62 runs around the last deflection roller 54 and is taken up by a storage roller 66. It can then be separated.

Another manufacturing method is used in the device 71 according to FIG. 6. The device 71 has three steaming stations 72, 73, 74, with the steaming stations 72, 73, 74 being assigned support rollers 75, 76, 77, which are flanked in the lower region by deflection rollers 78, 79 or 80, 81 or 82, 83, respectively are. A vapor deposition device 84, 85, 86 is arranged above each of the support rolls 75, 76, 77.

In front of the first support roller 75 there is a supply roll 88 on which a carrier film 89 is rolled up. A further supply roll 90 is arranged above the supply roll 88, on which a masking film 91 is rolled up. Associated with the further supply roll 90 is a laser device 92, with the aid of which recesses — designated 93, for example, are burned out of the masking film 91.

In front of the second support roller 76 there is a third supply roll 94 on which a second masking film 95 is rolled up. The third supply roll 94 is also here a laser device 96 is assigned, with the aid of which recesses — designated 97 by way of example — are burned out of the mask film 95.

In operation, the carrier film 89 and the mask films 91, 95 are withdrawn from their supply rolls 88 or 90 or 94 at the same speed, for example by driving the support rollers 75, 76, 77. In this case, the mask films 91, 95 are just behind each associated supply roll 90 or 94, a pattern of recesses 93, 97 is burned in with the aid of laser devices 92, 96. By appropriate control of the laser beams generated by the laser devices 92, 96 - there may also be several of them - predetermined patterns or random patterns that are constantly changing, for example with the aid of a random generator, can be generated, but these are in a complementary context, which is explained further below becomes.

The carrier film 89 and the mask film 91 converge on the first deflection roller 78 and are carried along by the support roller 75. The mask film 91 lies on the outside on the carrier film 89. Both are guided past the first vapor deposition device 84 in the upper region of the support roller 75, the vapor deposition device 84 vapor-depositing a first ferromagnetic layer 98 in a first direction, which, however, only separates on the carrier film 89 in the region of the recesses 93. After the deflection roller 79 rotates, the masking film 91 is guided away from the carrier film 89 upwards and rolled onto a storage roller 99. The carrier film 89 then runs horizontally to the next deflecting roller 80 and merges there with the second mask film 95. Both then run onto the support roller 76. With the aid of the vapor deposition device 85, a second ferromagnetic layer layer 100 is evaporated onto the carrier film 89 in a second direction deviating from the first. Here, the deposition on the carrier film 89 is also limited to the area of the recesses 97. The recesses 97 are arranged such that they only leave areas on the carrier film 89 that were covered in the first coating station 72 by the masking film 91 there. The different vapor deposition directions of the vapor deposition devices 84, 85 result in regions with different directions of the easy axes of the magnetic anisotropy.

Subsequently, the carrier film 89 coated in this way wraps around the deflection rollers 81, 82 and thus reaches the last support roller 77. With the aid of the further vapor deposition device 86 present there, a protective layer 103 is applied to the ferromagnetic coding layer 102. After passing the last deflection roller 83, the carrier film 89 provided with the coding coating is rolled up onto a storage roller 103. It can then be assembled according to its respective use.

FIG. 7 shows a further device 111 for the production of a marking device with area-specific anisotropy. It has in the order of passage a first steaming station 112, an ion bombardment station 113 and a second steaming station 114. The stations 112, 113, 114 are assigned support rollers 115, 116, 117, each of which has two deflection rollers 118, 119 or 120, 121 or 122 in the lower region, 123 are flanked.

The steaming stations 112, 114 are each provided with a steaming device 124, 125 arranged above the associated support roller 115, 117. An ion bombardment device 127 is arranged in the ion bombardment station 113 above the associated support roller 116. Below the support roller 116 and between the associated deflection rollers 120, 121, a charge distribution device 128 is arranged on the left-hand side, with which areas with positive and / or areas of negative charge can be generated on the support roller 116. This can be done, for example, according to the principle of the laser printer. For this purpose, the support roller 116 is provided with an electrically chargeable coating 129. To the right of the charge distribution device 128 there is an extinguishing device 130 which either completely discharges the surface of the support roller 116 or provides it with a homogeneous electrical charge.

A carrier film 132 is rolled up on a supply roll 131. In operation, the carrier film 132 is pulled off the supply roll 131, for example by driving the support rolls 115, 116, 117, rotates around the first deflection roll 118 and reaches the circumference of the first support roll 115, where it is carried by it. It runs past the first vapor deposition device 124 and there is provided with a ferromagnetic layer 133 by sputtering under a homogeneous magnetic field. With this layer 133, the carrier film 132 runs around the subsequent deflection rollers 119, 120 and then runs onto the jacket of the second support roller 116 and wraps around it. In doing so, it runs past the ion bombardment device 127, which bombards the layer 133 over the entire width of the carrier film 132. Due to the charge distribution on the surface of the support roller 116, which was previously generated by the charge distribution device 128, areas are created on the surface of the first layer 133 with potential for repelling and attracting the ions from the ion bombardment device 127. In the regions with an attractive potential, the layer 133 is influenced in such a way that the direction of the magnetic anisotropy is changed, so that a coding layer 134 is formed.

The backup roller 116 is homogenized by the extinguishing device 130 in front of the charge distribution device 128 as it passes through, i.e. either fully discharged or provided with a homogeneous charge, so that the charge distribution device 128 can repeatedly charge a new, randomly generated distribution pattern onto the support roller 116.

After the deflection roller 121, 122 rotates, the carrier film 132 reaches the second vapor deposition station 114, in which case it is again guided over the circumference of the support roller 117. There, the layer 133 receives a protective layer 135 over the entire surface with the aid of the vaporization device 125. The carrier film 132 then runs around the last deflection roller 123 and is rolled up onto a storage roller 136. It can then be separated.

It goes without saying that the devices 71, 111 shown in FIGS. 6 and 7 are also arranged within a housing which is under high vacuum.

Claims

Expectations:

1. Marking device (21) for marking objects, with a coding of areas (24, 25) with different magnetic properties, characterized in that magnetic areas (24, 25) made of a homogeneous, ferro- or ferrimagnetic material are present, which each have a magnetic anisotropy with a magnetically light and hard axis, with areas with different directions of the easy axes and/or areas with remanences of different strengths following one another in at least one specific direction.

2. Marking device according to claim 1, characterized in that magnetic areas (24, 25) directly border one another in the specific direction.

3. Marking device according to claim 1 or 2, characterized in that magnetic areas are spaced apart in the specific direction.

4. Marking device according to claim 3, characterized in that the areas between the magnetic areas cannot be magnetized.

5. Marking device according to one of claims 1 to 4, characterized in that the magnetic areas have saturation magnetizations of the same size.

6. A method for producing a marking device according to one of claims 1 to 5, characterized in that a coding layer (23) made of a homogeneous, ferromagnetic or ferrimagnetic material is applied to a carrier (22) and that areas (24, 25) with magnetic anisotropy with a magnetically light and hard axis can be generated in such a way that areas with different directions of the easy axes and / or areas with remanences of different strengths follow one another in at least one specific direction.

7. The method according to claim 6, characterized in that the coding layer (23) is constructed in such a way that magnetic areas (24, 25) directly adjoin one another in the specific direction.

8. The method according to claim 6 or 7, characterized in that the coding layer is constructed in this way that the magnetic areas are spaced in the specific direction.

9. The method according to claim 8, characterized in that the coding layer is constructed in such a way that the areas between the magnetic areas cannot be magnetized.

10. The method according to one of claims 6 to 9, characterized in that the coding layer (23) is constructed in such a way that the magnetic areas (24, 25) have saturation magnetizations of the same size.

11. The method according to any one of claims 6 to 10, characterized in that the coding layer (23) is built up by vapor deposition.

12. The method according to any one of claims 6 to 11, characterized in that a protective layer (65, 101, 135) is applied to the coding layer (63, 64, 100, 134), in particular by vapor deposition.

13. The method according to any one of claims 6 to 12, characterized in that the coding layer (63) is subjected to an inhomogeneous magnetic field during layer construction.

14. The method according to claim 13, characterized in that a magnetizable carrier is magnetized inhomogeneously to build up the magnetic field.

15. The method according to claim 13, characterized in that to build up the magnetic field, a magnetizable base (58) is magnetized inhomogeneously and that the carrier (62) is placed on this base (58) and the structure of the coding layer (63) on the combination of the base (58) and carrier (62).

16. The method according to claim 15, characterized in that a carrier film is withdrawn from a supply and brought together with a continuously moving magnetic film and both are passed through a coating station in which the coding layer is applied.

17. The method according to claim 16, characterized in that the carrier film and magnetic film are separated after the coating station.

18. The method according to claim 16 or 17, characterized in that the magnetic film is withdrawn from a supply and then magnetized and stored in a memory after the coating station.

19. The method according to claim 16 or 17, characterized in that the magnetic film (58) is passed in circulation through the coating station.

20. The method according to claim 19, characterized in that the magnetic film (58) is magnetized before the coating station (47) and demagnetized after the coating station (47) or its magnetization is homogenized.

21. The method according to claim 13, characterized in that the magnetic field is built up with coils that generate magnetic fields.

22. Device for carrying out the method according to one of claims 13 to 21, characterized by:

a) a storage facility (61) for a carrier film (62);

b) a coating station (47) for building up the coding layer (63);

c) a magnetic field device (59) assigned to at least the coating station (47) for generating an inhomogeneous magnetic field over the surface of the carrier film (62);

d) a recording memory (66) for recording the marking device; e) Guide devices (49 to 54) and a drive for guiding the carrier film (62) from the storage store (61) through the coating station (47) to the receiving store (66).

23. The device according to claim 22, characterized in that the magnetic field device is arranged in front of the coating station and that a magnetizable carrier film is guided through it.

24. The device according to claim 22, characterized in that the magnetic field device has a magnetic film which is inhomogeneously magnetized, and that the guide devices bring together the carrier film and magnetic film in front of the coating station.

25. The device according to claim 24, characterized in that a storage memory for the magnetic film is provided in front of the coating station and a storage memory after the coating station and that the magnetic field device has a magnetizing device which is arranged between the storage storage and the coating station.

26. The device according to claim 24, characterized in that the magnetic film is endless and is guided through the coating station together with the carrier film via the guide devices.

27. The device according to claim 26, characterized in that the magnetic field device has a magnetizing device in front of the coating station, seen in the running direction of the carrier film, which generates an inhomogeneous magnetic field, and that an erasing device for demagnetizing or homogenizing the magnetic field is provided between the coating station and the magnetizing device.

28. The device according to claim 26 or 27, characterized in that the magnetic film is stretched on a support roller which is assigned to the coating station.

29. The device according to claim 22, characterized in that the coating station (47) is assigned a support roller (49), over the roller shell (58) of which the carrier film (62) is guided past the coating station (47), and that the roller shell (58 ) is designed to be magnetizable.

30. The device according to claim 29, characterized in that the magnetic field device has a magnetizing device (59) for magnetizing the roll shell (58), which generates an inhomogeneous magnetic field, and that an erasing device (60) is provided for demagnetizing or homogenizing the magnetic field.

31. Device according to claim 29 or 30, characterized in that the roll shell has a magnetizable coating (58).

32. Device according to one of claims 28 to 31, characterized in that the erasing device (60) and magnetizing device (59) are arranged one after the other in the direction of rotation of the support roller (47) in the area of the support roller (47) which is free of the carrier film (62 ) is.

33. The device according to claim 22, characterized in that the magnetic field device has a plurality of magnetic field-generating coils.

34. The device according to claim 33, characterized in that the coils are arranged in the area of the surface of a carrier roller, over the roller shell of which the carrier film is guided through the coating station.

35. Device according to one of claims 22 to 34, characterized in that at least the coating station is assigned a heating device for generating a homogeneous temperature field.

36. Device according to one of claims 22 to 35, characterized in that a further coating tung station (48) is provided for applying a protective layer (65) to the coding layer.

37. Device according to one of claims 22 to 36, characterized in that the coating stations (47, 48) have at least one vapor deposition device.

38. Device according to one of claims 22 to 37, characterized in that the storage store or stores and the storage store or stores are designed as storage rolls (61) or storage rolls (66).

39. Device according to one of claims 22 to 38, characterized in that the coating stations (47, 48) have at least one carrier roller (49, 50), over the roller jacket of which the carrier film (62) is guided.

40. The method according to one of claims 6 to 12, characterized in that the areas are constructed with a vapor deposition direction that is oblique to the surface of the carrier (89), at least two different vapor deposition directions being used.

41. The method according to claim 40, characterized in that rectified magnetic fields act in the vapor deposition directions.

42. The method according to claim 40 or 41, characterized in that during vapor deposition in a first vapor deposition direction, areas of the carrier (89) are covered with a first mask (91) and that during vapor deposition in a second vapor deposition direction, at least the areas of the carrier (89) , which have been vapor-deposited with the first vapor deposition direction, are covered with a second mask (95).

43. The method according to claim 42, characterized in that during vapor deposition in the second vapor deposition direction with the second mask, areas that have not previously been vaporized are also covered and at least some of these areas are vaporized in a third vapor deposition direction after removal of the second mask and application of a third mask .

44. The method according to claim 42 or 43, characterized in that a carrier film (89) and at least two mask films (91, 95) are each removed from a supply (88, 90, 94) and the carrier film (89) and one before each vapor deposition the mask films (91, 95) are brought together and then the vapor deposition takes place from the side of the mask film (91, 95) and the mask film (91) is separated again from the carrier film (89) before the carrier film (89) is covered with another mask film ( 95) is merged.

45. The method according to claim 44, characterized in that the mask films (91, 95) are provided with recesses (93, 97) after deduction from the supply (90, 94) and before being combined with the carrier film (89).

46. Device for carrying out the method according to one of claims 40 to 45, characterized by:

a) a storage facility (88) for a carrier film (89);

b) a plurality of coating stations (72, 73) for vapor deposition of the carrier film (89) in different vapor deposition directions;

c) a number of storage stores (90, 94) for mask films (91, 95) corresponding to the number of coating stations (72, 73);

d) recording memory for recording the mask films;

e) a recording memory (104) for recording the marking device;

f) guide devices (75 to 83) and a drive for guiding the carrier film (89) from the storage store (88) through the coating stations (72, 73) to the receiving store (104) and for combining the carrier film (89) with a mask film (91, 95) before a coating station (72, 73) and for separating the carrier film (89) and mask film (91, 95) after a coating station (72, 73).

47. The device according to claim 46, characterized in that each coating station (72, 73) has a storage memory (90, 94) for a mask film (91, 95) and a storage memory (99, 101) for receiving the mask film (91, 95 ) assigned.

48. The device according to claim 46 or 47, characterized in that there is a mask forming station (92, 96) between the storage (90, 94) for the mask film (91, 95) and the combination of the mask film (91, 95) and the carrier film (89). ) is arranged for forming recesses (93, 97) in the mask film (91, 95).

49. The device according to claim 48, characterized in that the mask formation station (92, 96) has a laser burning device.

50. The device according to claim 49, characterized in that the mask formation stations (92, 96) each have a control device for variable location control of the laser burning device.

51. Device according to one of claims 46 to 50, characterized in that a further coating station (74) is provided for applying a protective layer (103) to the coding layer (102).

52. Device according to one of claims 46 to 51, characterized in that the storage stores are designed as storage rolls (88, 90, 94) and the receiving stores are designed as storage rolls (99, 101, 104).

53. Device according to one of claims 46 to 52, characterized in that the coating stations (72, 73, 74) have carrier rollers (75, 76, 77), over the roller shell of which the carrier film (89) and the mask films (91, 95) are guided.

54. The method according to one of claims 6 to 12, characterized in that a homogeneously magnetized layer is first built up and the layer

a) a homogeneous magnetic field and an inhomogeneous temperature field or

b) an inhomogeneous magnetic field and a homogeneous temperature field or

c) an inhomogeneous magnetic and temperature field is exposed, the temperature being above the Curie temperature of the layer.

55. The method according to claim 54, characterized in that a magnetizable carrier is magnetized to build up the magnetic field.

56. The method according to claim 54, characterized in that a magnetizable base is magnetized in the construction of the magnetic field and that the carrier with the layer is placed on this base and the combination of base and carrier is exposed to the temperature field.

57. The method according to claim 56, characterized in that a carrier film is removed from a supply and brought together with a continuously moving magnetic film as a base and both are guided through a heating station.

58. The method according to claim 57, characterized in that the carrier film and magnetic film are separated after the heating station.

59. The method according to claim 57 or 58, characterized in that the magnetic film is withdrawn from a supply and then magnetized and stored in a memory after the heating station.

60. Method according to claim 57 or 58, characterized in that the magnetic film is passed in circulation through the heating station.

61. The method according to claim 60, characterized in that the magnetic film is magnetized before the heating station and demagnetized after the heating station or its magnetization is homogenized.

62. Device for carrying out the method according to one of claims 54 to 61, characterized by:

a) a storage facility for a carrier film;

b) a treatment station with magnetizing device and heating device;

c) a recording memory for recording the marking device;

d) Guide devices and a drive for guiding the carrier film from the storage storage through the treatment station to the receiving storage.

63. Device according to claim 62, characterized by:

a) a coating station for applying a homogeneously magnetized layer to the carrier film; b) Guide devices and a drive for guiding the carrier film from the storage storage through the coating station and the treatment station to the receiving storage.

64. Device according to one of claims 62 or 63, characterized in that the magnetizing device has a magnetic film that is magnetized, and that the guide devices bring together the carrier film and magnetic film in front of the treatment station.

65. The device according to claim 64, characterized in that a storage store for the magnetic film is provided in front of the treatment station and a storage store after the treatment station and that the magnetizing device is arranged between the storage store and the heating device.

66. The device according to claim 64, characterized in that the magnetic film is endless and is guided through the heating device via the guide devices together with the carrier film.

67. The device according to claim 66, characterized in that the magnetizing device is arranged in front of the heating device as seen in the running direction of the carrier film and generates an inhomogeneous magnetic field, and that an erasing device for demagnetizing tization or homogenization of the magnetic field between the heating device and the magnetizing device is provided.

68. Device according to claim 66 or 67, characterized in that the magnetic film is stretched onto a support roller which is assigned to the treatment station.

69. The device according to claim 62, characterized in that the treatment station is assigned a support roller, over the roller shell of which the carrier film is guided past the treatment station, and that the roller shell is designed to be magnetizable.

70. The device according to claim 69, characterized in that the magnetizing device generates an inhomogeneous magnetic field and that an erasing device is provided for demagnetizing or homogenizing the magnetic field.

71. Device according to claim 69 or 70, characterized in that the roll shell has a magnetizable coating.

72. Device according to claim 70 or 71, characterized in that the erasing device and magnetizing device follow in the direction of rotation of the support roller. each other in the area of the support roller that is free of the carrier film.

73. Device according to one of claims 62 to 72, characterized in that the treatment station has heating devices for local heating.

74. Device according to claim 73, characterized in that the heating device (s) has at least one laser.

75. Device according to claim 73 or 74, characterized in that the treatment station has a magnetizing device for generating a homogeneous magnetic field.

76. The device according to claim 75, characterized in that the treatment station has a heating device for generating a homogeneous temperature field and a magnetizing device for generating an inhomogeneous magnetic field.

77. Device according to one of claims 62 to 76, characterized in that a further coating station is provided for applying a protective layer to the second layer.

78. Device according to one of claims 62 to 77, characterized in that the coating station has one or more vapor deposition devices.

79. Device according to one of claims 62 to 78, characterized in that the storage memory is designed as a storage roll and the storage memory is designed as a storage roll.

80. Device according to one of claims 63 to 79, characterized in that the coating station and the treatment station have carrier rollers, over the roller shell of which the carrier film is guided.

81. The method according to one of claims 6 to 12, characterized in that at least one homogeneously magnetized layer (133) is built up and the layer (133) is locally subjected to ion bombardment in such a way that there is a local change in the easy axis and/or or the remanence comes.

82. The method according to claim 81, characterized in that the ion bombardment takes place with the aid of a focused ion beam.

83. The method according to claim 81, characterized in that the ion bombardment takes place over a large area and an inhomogeneous electric charge field is generated in the area of the carrier (132).

84. Method according to one of claims 81 to 83, characterized in that an electrically charging Bare carrier is inhomogeneously electrically charged before the ion bombardment.

15. The method according to claim 83, characterized in that an electrically chargeable base (129) is electrically charged inhomogeneously and that the carrier (132) is placed on this base (129) and the ion bombardment on the combination of base (129) and carrier (132) takes place.

16. The method according to claim 85, characterized in that a carrier film is removed from a supply and, after coating, is brought together with a continuously moving charge film (129) as a base and both are exposed to ion bombardment.

i7. Method according to claim 86, characterized in that the carrier film and charge film are separated after the ion bombardment.

58. The method according to claim 86 or 87, characterized in that the charge film is withdrawn from a supply and then charged and taken into a memory after the ion bombardment.

59. The method according to claim 86 or 87, characterized in that a charge film (129) as a base is passed in circulation through an ion bombardment station (113) and the charge film (129) is charged before the ion bombardment station (113) and after Ion bombardment station (113) is discharged or the electrical charge is homogenized.

90. The method according to claim 81 or 82, characterized in that a carrier film and a mask film are continuously removed from a supply and brought together and that the ion bombardment then takes place from the side of the mask film and the mask film is separated again from the carrier film.

91. The method according to claim 90, characterized in that the mask film is provided with recesses after deduction from the supply and before being combined with the carrier film.

92. Device for carrying out the method according to one of claims 81 to 91, characterized by:

a) a storage facility (131) for a carrier film (132);

b) an ion bombardment station (113) for applying ion beams to the layer (133);

c) a recording memory (136) for the marking device;

d) guide devices (115 to 123) and a drive for guiding the carrier film (132) from Storage storage (131) through the ion bombardment station (113) to the storage storage (136).

93. Device according to claim 92, characterized by:

a) a coating station (112) for applying a homogeneously magnetized layer (133) to the carrier film (132);

b) Guide devices (115 to 123) and a drive for guiding the carrier film (132) from the storage store (131) through the coating station (112) and the ion bombardment station (113) to the receiving store (136).

94. Device according to claim 92 or 93, characterized in that the ion bombardment station generates a focused ion beam and a control device is provided for the targeted control of the ion beam.

95. Device according to claim 92 or 93, characterized in that an electrically chargeable carrier film is guided through the ion bombardment station and is provided with an inhomogeneous electrical charge via a charging device.

96. Device according to claim 92 or 93, characterized in that an electrically chargeable charge film is guided through the ion bombardment station, which is provided with an inhomogeneous electrical charge, and that the guide devices bring together the carrier film and the charge film in front of the ion bombardment station.

97. The device according to claim 96, characterized in that a storage memory for the charge film is provided in front of the ion bombardment station and a storage memory after the ion bombardment station as well as a charging device for inhomogeneous charging of the charge film between the storage memory and the ion bombardment station.

98. The device according to claim 96, characterized in that the charging film is endless and is guided through the ion bombardment station together with the carrier film via the guide device and that the charging device, viewed in the direction of travel of the carrier film, is in front of the ion bombardment station and an extinguishing device for discharging or homogenizing the electrical Charge between ion bombardment station and charging device are provided.

99. The device according to claim 98, characterized in that the charge film is stretched onto a support roller which is assigned to the ion bombardment station.

100. Device according to claim 92 or 93, characterized in that the ion bombardment station (113) is assigned a support roller (116), over the roller shell (129) of which the carrier film (132) is guided past the ion bombardment station (113), and that the roller shell (129) can be charged with an electrical charge, a charging device (128) for charging the roll shell (129) and an extinguishing device (130) for discharging or homogenizing the electrical charge of the roll shell (129) being provided.

101. Device according to claim 100, characterized in that the roll shell (129) has a coating that can be charged with an electrical charge.

102. Device according to one of claims 98 to 101, characterized in that the unloading device (130) and the charging device (128) are arranged one after the other in the direction of rotation of the support roller (116) in the area of the support roller (116) which is free of the carrier film (132) is.

103. The device according to claim 92 or 93, characterized in that a mask film is guided through the ion bombardment station and that the guide device brings together the carrier film and mask film in front of the ion bombardment station in such a way that the ion bombardment takes place from the side of the mask film, and that the management facility Separate the carrier film and mask film after the ion bombardment station.

104. The device according to claim 103, characterized in that a mask forming station for forming recesses in the mask film is arranged between a storage facility for the mask film and the combination of mask film and carrier film.

105. Device according to claim 104, characterized in that the mask formation station has a laser burning device.

106. The device according to claim 105, characterized in that the mask formation station has a control device for variable location control of the laser burning device.

107. Device according to one of claims 92 to 106, characterized in that a further coating station (114) is provided for applying a protective layer (135) to the layer (133).

108. Device according to one of claims 93 to 107, characterized in that the coating station (s) (112, 114) has at least one charging device (124, 125).

109. Device according to one of claims 92 to 108, characterized in that the storage memory as Supply roll and the recording memory are designed as a storage roll.

110. Device according to one of claims 93 to 109, characterized in that the coating station and the ion bombardment station have carrier rollers, over the roller jacket of which the carrier film is guided.

111. Method for reading out marking device according to one of claims 1 to 5, with the aid of a magnetic field sensor, characterized in that the coding is subjected to at least two readout processes, with a readout process in a zero field and a readout process in an external magnetic field or the readout processes in different external magnetic fields.

112. The method according to claim 111, characterized in that a readout process is carried out at saturation magnetization.

113. Method for reading out marking devices according to one of claims 1 to 5 with the aid of a magnetic field sensor, characterized in that at least one reading process is carried out in which the remanence is detected.

114. Method for reading out marking devices according to one of claims 1 to 5 with the aid of a magnetic field sensor, characterized in that at least one readout process is carried out in such a way that the flux change is detected at the boundary of two magnetic areas.

Method for reading out marking devices according to one of claims 1 to 5 with the aid of a magnetic field sensor, characterized in that at least two reading processes are carried out without an external magnetic field and that the coding is carried out before a reading process in one direction and before a further reading process in another direction up to Saturation is magnetized.