EP0655032A1

EP0655032A1 - Anti-copy film or coating for documents.

Info

Publication number: EP0655032A1
Application number: EP93915945A
Authority: EP
Inventors: Helmut Steininger; Peter Heilmann; Peter Greenside Hewkin
Original assignee: BASF Magnetics GmbH
Current assignee: Emtec Magnetics basf AG GmbH; BASF Magnetics Holding GmbH
Priority date: 1992-08-14
Filing date: 1993-07-17
Publication date: 1995-05-31
Anticipated expiration: 2013-07-17
Also published as: GR3022252T3; RU95109101A; RU2102244C1; DK0655032T3; JPH08503788A; US5728449A; WO1994004367A1; ZA935912B; ATE143870T1; EP0655032B1; DE4226906A1; KR100268156B1; JP3309318B2; CN1086479A; BR9306906A; ES2094554T3; CN1060118C; DE59304143D1

Abstract

PCT No. PCT/EP93/01891 Sec. 371 Date Feb. 13, 1995 Sec. 102(e) Date Feb. 13, 1995 PCT Filed Jul. 18, 1993 PCT Pub. No. WO94/04367 PCT Pub. Date Mar. 3, 1994An anti-copy film or layer for originals or documents comprises according to the invention transparent film material having a multiplicity of at least partially opaque and possibly reflective areas arranged at distances from one another which are arranged as screens on the film surfaces essentially in horizontal planes, in particular parallel to one another, but offset, so that information on an original lying under this film or layer is masked in an approximately vertical viewing direction and is visible in the direction of a predefined viewing angle. Expedient production methods enable the use of photographic techniques.

Description

Anti-copy film or layer for documents

description

The invention consists in an anti-copying film or layer for documents, consisting of a film or a layer of transparent material with a plurality of spaced-apart, at least partially opaque areas, the planes of which are roughly predetermined Position opposite the surfaces of the film or layer are arranged so that the anti-copying film is substantially opaque from an approximately perpendicular viewing angle to the surfaces of the film or layer and from a predetermined viewing angle to the surfaces of the film or the layer of anti-copy film is essentially transparent.

An anti-copy film of the type described above is shown in US Pat

US-A 3 887 742. Such a film, which is intended to enable copy-proof documents, is effective in covering up graphic information and / or characters of a document or generally a piece of writing in a vertical line of sight, as is present in a copying machine, and the graphic information and / or characters to make it visible from a predetermined different point of view, related to the level of the document.

In practice, such an anti-copying film is a transparent plastic film with an opaque surface or with an indented or sawtooth-shaped surface in which a first oblique or vertical surface is either black or reflective with respect to a vertical viewing angle, based on the level of the film or the document, and the other oblique surface is transparent from a different angle, so that the information or characters can be read. Such notched or sawtooth-shaped surfaces are very difficult to produce, since the surfaces first have to be embossed or hammered in, and then the inclined surfaces have to be provided with a black or reflective material, the accuracy of these operations having to be so great that the transparent surfaces are not affected drawn, ie also partially provided with black and reflective material. Practical manufacturing designs are not described for the theoretical inclined surface formation within the film. An anti-copy medium for writing or printing is known from AU-A-610 614, in which the medium contains a photosensitive color system which, when irradiated in a photocopier, makes the writing illegible or makes the copy clearly distinguishable from the original so that either the original becomes worthless or clearly recognizable as copied.

It is an object of the present invention to provide an anti-copying film or layer which is easier to produce and more economical.

Anti-copy film or layer for documents, consisting of a film or a layer of transparent material with a plurality of spaced-apart, at least partially opaque areas, the planes of which are approximately in the same predetermined position with respect to the surfaces of the film or the layer are arranged so that the anti-copying film is essentially opaque from an approximately perpendicular viewing angle on the surfaces of the film or layer and from a predetermined viewing angle on the surfaces of the film or layer of the anti-copying film. The film is essentially transparent, in that each area is formed from at least first opaque covers on one of the surfaces of the film or layer and at least second opaque covers on the other of the surfaces of the film or layer, and in that the at least first and second covers essentially hori are arranged zonally.

This considerably simplifies the production of such a film, which is otherwise to be produced mechanically and / or chemically, and there are considerable possibilities of variation depending on the intended application.

In practice, the first and second covers can be arranged offset parallel to one another in horizontal planes.

In an expedient embodiment, the first and second covers can have approximately the same width (in cross section) and can be arranged on a gap without significant overlaps.

However, it is also possible for the first and second covers to have approximately the same width and to be arranged on a gap with overlaps. It may also be appropriate to design the first and second covers with different widths. In practice, the covers can be applied as a line structure on both sides to a transparent film or layer, in particular in terms of printing technology.

This is a very cheap producibility for the mass production of such films and layers.

In practice, such a film according to the invention is characterized in that a first photosensitive layer is applied to a transparent film on the one hand, directly exposed and developed, and that a second photosensitive layer is subsequently applied to the transparent film on the other hand, directly exposed and is developed.

A further practical training is given in that a first photosensitive layer is applied to a transparent film on the one hand, is directly exposed and developed, and that a second photosensitive layer is then applied to the transparent film on the other hand, indirectly through the first developed, photosensitive Layer and the film is exposed and developed.

A further variant consists in that on the one hand a line structure and on the other hand a photosensitive layer is applied to a transparent film, and the photosensitive layer is exposed and developed through the line structure.

The exposure can take place by means of parallel or divergent radiation, so that either there is almost no overlap of the covers or just one overlap.

An advantageous embodiment results from the fact that, on the one hand, a negative resist layer is applied to a transparent film and a positive resist layer is applied to the other side, and both layers are exposed by exposure through a line structure mask from the side of the negative resist layer and both layers are washed out are formed.

The photosensitive layer material can expediently be a photographic emulsion or else a plastic layer with photoinitiators.

It is also advantageous if a non-opaque layer material is made opaque before application, in particular by adding colors. A non-opaque layer material can be provided with opaque material, for example color, after the application, exposure and development at the raised or deepened areas.

The finished layers with the covers can also be sealed against damage by means of a transparent lacquer coating.

Further patent claims relate to a multi-film or multi-layer design of the anti-copying film according to the invention and to advantageous dimensioning ranges for the covers, the film or the layer or a possible carrier film in order to achieve largely optimal covering and viewing conditions. Specifically, the at least partially opaque and / or reflective covers can be essentially in the form of strips and can be arranged approximately parallel to and equidistant from one another.

The invention is described below with the aid of drawings in individual embodiments.

Show it

Fig. 1, a and b

Designs of copy security films according to the state of the art with inclined surfaces

2, a and b anti-copying films according to the invention with covers

Fig. 3 covers according to the invention, produced by double-sided photosensitive layers

4 covers according to the invention formed by exposure of a photosensitive layer through a pressure mask

5, ac schematic production of covers according to the invention by means of negative resist material 6, ac schematic production as in FIG. 5, ac, however, by means of positive resist material

7, a and b schematic production of covers according to the invention on both sides by simultaneous use of negative and positive resist material

8 and 9 are schematic geometric representations of an inventive

Anti-copy film

Fig. 10 is a multiple film version of the anti-copy film according to the invention

Definitions:

Covers

For the purposes of the invention, these covers are intended to cover optically. In extreme cases, a very thin opaque and possibly additionally reflective layer is sufficient for this. The layer thickness can reach without further film thickness.

exposure

Can be done through optical masks, which are placed on the layer to be exposed (in contact).

Can also be done contactlessly by means of scanners, several light sources (e.g. photodiode arrangement [array]), the multiple light sources also being able to be generated optically, e.g. by diffraction gratings.

Light source

is any radiation emitting device.

radiation

is generated by all electromagnetic sources, including every corpuscular radiation (eg electron beams). development

Chemical development in photographic layers and washing out with a suitable solvent or water in photosensitive plastics.

description

Figure la shows a known theoretical copy protection film, consisting of a thin transparent plastic material Q on a transparent support material G, wherein in the material Q a number of parallel and equally spaced, opaque, oblique planes in the angular range of γ = 50 to 70 °, preferably from 60 ° to the surface of the material Q are provided. The layers should be black or reflective. The copy protection film can be attached to the original to be protected using adhesive or other types of adhesive. The oblique opaque planes are said to be approximately 2.5 microns thick and approximately 25 microns apart. The implementation of such a theoretical copy protection film is not described.

FIG. 1b shows a copy protection film 11 described in the same US Pat. No. 3,887,742 with a plastic material Z, which has a sawtooth-shaped surface 12, which likewise consists of transparent plastic. The oblique tooth flanks V (see thicker line width) should be black or reflective, while the vertical flanks W are transparent.

As in the example above, the information on an original is erased or obscured with a vertical viewing or copying direction and the information is made visible with an oblique viewing direction (angular range γ as stated above).

Embodiments of the present invention are shown schematically in FIGS. 2a and 2b.

In contrast to the known copy protection films in FIGS. 1 a and 1 b, in which, without exception, inclined planes or surfaces are used as optical concealment means, the present invention takes the following route.

Anti-copying films or layers here consist of a transparent film or a transparent layer S (hereinafter referred to only as film S), which is provided with approximately parallel and strip-shaped covers A, which are described above (AI ) and below (A2) on the film surfaces and with gaps L to each other and under defined (approx. ten) viewing angles as optical covers and at other viewing angles approximately 30-73 °, in particular approximately 45 ° to approximately 60 °, are intended to serve as optical openings.

The covers AI and A2 are arranged essentially horizontally, which means that although slight deviations from the horizontal plane are harmless, they are not necessary in the sense of the invention, such as the inclined plane arrangement in FIGS. 1a and 1b.

The covers AI and A2 have the same or different dimensions as can be seen from the comparison of FIGS. 2a and 2b. In FIG. 2a, essentially the same widths of AI and A2 are used at the top and bottom, while in FIG. 2b the widths of the covers A2 'are larger than those of the covers AI'.

The geometric considerations necessary for the practical application of such films with covers are explained below with reference to the schematic diagrams of FIGS. 8 and 9.

φ: Effective opening angle of standard copiers 6 ° <_ φ / 2 <54 °

dg: width of covers AI, A2

do: width of the gap L between the covers

s: thickness of the film S

h: thickness of a possible carrier film F

x: Overlap width of covers AI and A2

p: sum of the widths dg and do

α: Average viewing angle for reading

Transmission of the arrangement

do

T- dg + do

It results from the geometry of the sketch (Fig. 8! tan φ 2 = x / s = Y

for the mean viewing angle α = 45 °

dg + do = 2 s

do = 2 s - dg

dg = s + x

dg> s if α> 45 °

With A = 1 / tan α and A> Y

surrendered

dg = s (A + Y)

do = s (A - Y)

and follows for the transmission

do

T- dg + do

= 1/2 (A-Y).

With the angular range 6 ° <φ / 2 <54 °, the system parameter inequality becomes

0.05 <Y <0.5

receive.

If the angular range is limited to 6 = <φ / 2 <12 °, the result is

0.05 Y ≤. 0.1.

It is assumed for the viewing angle range

A = 1 / tan α and 73 ° <α <30.5 °, from this follows:

0.3 <A a. 1.7 The film thickness s is in the large range from approx. 5 μ to approx. 300 μ, in particular between approx. 20 μ and 100 μ.

For this calculation example, the film thickness s is practically in the range of

5 μ <s <100 μ.

The areas for do and dg follow:

The values of do and dg show what great influence the viewing angle α has for dimensioning.

If a carrier film F is used, the longer path (h) of the light rays must also take into account the fact that, in addition to the visible area, there is also an invisible area a on the document D which is "optically switched off" by the covers AI, A2.

The relationship is:

h = 2 s - a or 2 - y

a = 2 s - h (2 - y)

for h (2 - y) »2 s

goes a

When h is increased, a strives towards zero, which is desirable

The value has the maximum value for a

a <_ 0.3 dg exposed. A very small invisible area a is thus obtained. The values of h min were included in the table above for clarification, the different values also showing the considerable influence of A and α on h min.

In the above consideration, the thickness of the covers, which could increase the value a, was neglected.

The following is described by way of example for the production of the anti-copying films or foils according to the invention.

The anti-copy films 13 and 14 can be printed using all suitable printing methods with the parallel line structures (covers) AI, L; Manufacture A2, L or AI ', L' as well as A2 ', L' on one or both sides at the same time. The exact positioning of the covers AI and AI 'to their counterparts A2 and A2' is assumed and depends on the respectively given viewing angle α.

The thickness of the printing layers is of the order of magnitude of less than 1 μm, so that the above fear of obtaining enlarged invisible areas a becomes irrelevant.

In Figure 3, the parallel line structures AI, L; A2, L or AI ', L' and A2 ', L' produced photographically by applying or coating photosensitive layers B1 or B2 one after the other on both sides of the film S.

First, e.g. the layer B1 in a suitable technique, e.g. Laminating, spraying, etc., applied, then exposed through a mask Ml and developed in a suitable manner.

Layer B2 is then applied, exposed through M2 (which corresponds to Ml and can also be Ml) and then developed. Exposure of layer B2 can expediently also take place through layer B1 which has already been exposed and developed. This would make the mask M2 obsolete.

The exposure is carried out with suitable light sources and is symbolized by the arrows b.

FIG. 4 shows a variant for producing the anti-copying film 15 in FIG. 3 using the anti-copying film 16. First, the line structure LS is applied to one side of the film S in terms of printing technology. The photosensitive layer B is then exposed through the print line structure, which thus takes over the mask function. Depending on the desired overlap area the covers AI and A2 are exposed with parallel light radiation (collimated light) or divergent light. In the case of parallel light, the arrangement of the covers AI and A2 does not overlap on the gap (FIG. 2a) and overlaps in the case of divergent light, as in FIG. 2b, for example.

FIG. 5 shows an anti-copying film 17 with a photosensitive layer BN and FIG. 6 shows an anti-copying film 18 with a photosensitive layer BP.

BN stands for negative photoresist material and BP for positive resist material.

These materials differ functionally in that the negative resist hardens in the exposed areas and the positive resist becomes more soluble, ie washable, in the exposed areas.

Negative photoresists are generally based on photopolymerizable mixtures which, in addition to a polymeric binder, contain a photopolymerizable compound with a photoinitiator. Such mixtures contain e.g. partially cyclized polyisoprene as a polymerizable compound and a diazide compound as a light-sensitive difunctional crosslinker (photoinitiator). Partially cyclized polybutadiene is also known as a polymerizable compound and diazides (see above).

Positive-working photoresists are conventional systems consisting of a photo-insensitive alkali-soluble matrix based on novolaks and a photosensitive component which acts as a solubility inhibitor and is converted into alkali-soluble products by exposure, so that the entire exposed areas become soluble in the alkaline development solvent.

Resists for the short-wave UV range are also e.g. Poly-methyl methacrylate, copolymers of methyl methacrylate and indenone and of methyl methacrylate and 3-oximino-2-butanone are known as photoactive components. Two-component systems composed of a poly-methyl-methacrylate-co-methacrylic acid matrix and o-nitrobenzyl esters are also known, e.g. Esters of cholic acid, as solubility inhibitors ..

Suitable photoresist materials can be selected for the purpose of the invention, if appropriate using suitable transparent adhesives or adhesives, and can be used with advantage. In FIG. 5, after exposure to radiation (arrows b) through a mask M, the parts M1 and M2 remain as hardened parts, which form the covers, after the development of the negative resist layer BM (FIG. 5b).

In FIG. 6, after exposure to radiation (arrows b) through a mask M and subsequent development, the non-exposed parts P1, P2 and P3 of the layer BP remain and form the covers. (Fig. 6b).

If in these two cases the materials of the resist layers BN and BP are not opaque or opaque, the washed spaces R1-R3 in FIG. 5c and R4-R5 can be coated with opaque material, e.g. Color pigments or the like can be filled out in a suitable manner, so that in this case the covers are realized by the spaces R1-R5. In these cases, however, the resist material must be transparent.

A further production method for an anti-copying film 19 is shown in FIG. 7, the upper layer being a negative resist layer BN and the lower layer being a positive resist layer BP.

After exposure of the layer BN and development, after which the hardened parts N1 and N2 remain, exposure is again carried out from above (arrows b) through the finished upper layer, which serves as a mask for the lower layer BP in the exposure process , so that the parts P1-P3 remain after development. In this case, either the negative resist material of the layer BN must be opaque or the same by exposure and washing out, or a mask M must be used, or the parts N1 and N2 must be colored opaque before the second exposure, by a Cover layer AS, as indicated in Fig. 7b.

Depending on which option is used, either the raised parts Nl, N2 and P1-P3 must be colored opaque, or the gaps, as described for FIGS. 5c, 6c, must be made opaque when the parts Nl, N2 and P1 -P3 are transparent.

In all cases in FIGS. 2 to 7, it is also possible to coat the finished covering layers with a preferably transparent protective lacquer after the anti-copying films have been produced.

The photosensitive layers are applied to the film S in a conventional manner. For example, it is known to apply very thin layers by means of adsorptive or adhesive techniques. In general, it can be assumed that the layers produced photographically or photopolymerically have a thickness in the range from approximately 0.1 μm to approximately 10 μm or only slightly above.

In order to fix the anti-copying films described on the documents or generally originals or also copies, commercially available adhesives and adhesives can also be used.

In principle, electrostatic or adhesive forces can of course also be used to attach the films.

FIG. 10 shows a further variant of the anti-copying films according to the invention, which is distinguished by a multilayer arrangement of individual films or layers.

As indicated, 3 individual films or layers S1-S3, each of which has covers A on one side only, can be transparently connected to one another.

However, 2 individual films or layers S1 and S2 can also be transparently connected to one another and to a carrier film F. The films S1 and S2 would be different in that film S1 or S2 would be provided with covers A on both sides and the other film S2 would only be formed with covers A (bottom) and S1 only with covers A (top) ought to. Multi-layer arrangements are also conceivable.

The physical transparency (light transmittance) is defined as the ratio of the quantity of light J transmitted to the quantity of light J _{0 that is} incident

ph =

The opacity (the opacity) is the reciprocal of it

Yo

Oph = J The materials referred to herein as "transparent", such as films, layers, adhesive or adhesive layers, should come as close as possible to the theoretical maximum value of transparency _P ~ 1, as should the opacity 0 _{Ph of} the materials referred to as "opaque" or light "opaque" the covers should be as large as possible. A large light scatter or light reflection of the material which is intended to act as a cover can also be as advantageous in the sense of the present invention as a material with high opacity if the ratio of the amount of light J ₀ which is incident is very much larger is as the let through J ₀ >> J.

Terms used here, such as at least "partially opaque areas", are therefore to be understood as at least "partially opaque" or "partially light reflecting" in the sense that the light from a copying machine is only produced by the anti-copying device in a quantity of light that is too small for the copying process. Film or the layer through to the original. Likewise, the term "essentially transparent" is again to be understood as translucent as possible in the sense of physical transparency.

According to the invention, an anti-copying film or layer for originals or documents consists of transparent film material with a large number of spaced-apart, at least partially opaque and possibly reflecting areas which act as covers on the film surfaces in the are arranged essentially in horizontal planes, in particular offset parallel to one another, so that information of an underlying original is hidden in an approximately vertical viewing direction and the information is visible in the direction of a predetermined viewing angle. Appropriate production methods enable the use of photo techniques.

Claims

1. Anti-copying - zl or layer (S) for documents, consisting of an F-m or a layer of transparent material with a Vii -._ 2.ahl of spaced, at least partially and -prepared areas, the Layers are arranged in approximately the same predetermined position with respect to the surfaces of the film or the layer (S), so that the anti-copying film in the film is from an approximately perpendicular viewing angle to the surfaces of the film or layer (S) is substantially opaque and the anticopy film is essentially transparent from a predetermined viewing angle on the surfaces of the film or layer (S), characterized in that each area composed of at least first opaque covers (AI) on one of the surfaces of the film or the layer (S) and at least second opaque covers (A2) is formed on the other of the surfaces of the film or layer (S), and that the at least one most and second covers (AI and A2) are arranged substantially horizontally.

2. Anti-copy film according to claim 1, characterized in that the first and second covers (AI and A2) are arranged offset parallel to each other in horizontal planes.

3. Anti-copy film according to claim 1, characterized in that the first and second covers (AI and A2) have approximately the same width (dg) and are arranged on a gap without significant overlaps.

4. Anti-copy film according to claim 1 or 2, characterized gekennzeich¬ net that the first and second covers have about the same width (dg) and are arranged on a gap with overlaps.

5. Anti-copy film according to claim 1 or 2, characterized by ^• different widths of the first and second covers

(AI ', A2').

6. Anti-copy film according to claims 1-5, characterized in that the covers (AI, A2) are applied as a line structure on both sides to a transparent film or layer (S), in particular by printing technology.

7. Anti-copying film according to claims 1-5, characterized in that a first photosensitive layer (B1) is applied on the one hand to a transparent film (S), directly exposed and developed, and in that a second photosensitive layer (B2 ) on the other hand applied to the transparent film (S), directly exposed and developed.

8. Anti-copy film according to claims 1-5 and 7, characterized gekenn¬ characterized in that a first photosensitive layer (B) on the one hand applied to a transparent film (S), directly exposed and developed and that after that a second photo-sensitive layer (B2) on the other hand applied to the transparent film (S), indirectly exposed and developed through the first developed photosensitive layer (B) and the film (S).

9. anti-copying film according to claims 1 to 6, characterized gekenn¬ characterized in that on a transparent film (S) on the one hand a line structure (LS) and on the other hand a photosensitive layer (B) is applied, the photosensitive layer (B) by the line structure (LS) is exposed and then developed.

10. Anti-copy film according to claim 9, characterized in that the exposure is carried out by means of parallel radiation, so that there is almost no overlap of the covers (AI, A2) er¬.

11. Anti-copy film according to claim 9, characterized in that the exposure is carried out by means of divergent light radiation, so that essentially an overlap of (AI ', A2') is obtained.

12. Anti-copy film according to claims 1-5, characterized in that on a transparent film (S) on the one hand a negative resist layer (BN) and on the other side a positive resist layer (BP) is applied and both Layers are formed by exposure through a line structure mask (M) from the side of the negative resist layer and washing out of both layers (BN, BP).

13. Anti-copying film according to claims 1-5 and one or more of claims 6 to 12, characterized in that the pho-sensitive layer material is a photographic emulsion.

14. Anti-copy film according to claims 1-5 and one or more of claims 6 to 12, characterized in that the layer material 3 is a plastic layer with photoinitiators.

5

15. Anti-copy film according to claims 1-5 and one or more of claims 6 to 12 and 14, characterized in that a non-opaque layer material is made opaque before application, in particular by color admixture.

16. Anti-copying film according to claims 1-5 and one or more of claims 6 to 12 and 14, characterized in that a non-opaque layer material after the application 5 gene, exposure and development at the raised or recessed locations with opaque material, e.g. Color is provided.

17. Anti-copy film according to one or more of claims 1-16, 0 characterized in that the finished layers with the

Covers are sealed by means of a transparent lacquer coating.

18. Anti-copy film or layer for documents, consisting of 5 at least one film or at least one layer of transparent material with a plurality of spaced apart, at least partially opaque areas, the planes of which are roughly the same predetermined position with respect to the surfaces of the Film or the layer (S) are arranged, characterized in that each area of at least first opaque covers on a surface of the first film or the first layer (S1) and at least second opaque covers on a surface of the second film or second layer (S2)

35 is formed, the first and second films or layers (S1, S2) being connected to one another in such a way that the first and second covers are arranged offset in horizontal planes and in particular parallel to one another.

40 19. Anti-copy film, according to claim 1 or 18 and one or more of claims 3-17, characterized in that the first and second covers have a width (dg) and the horizontal distance (do) between the first covers or between the second covers between 50 and 90%

45 of the width (dg) of the covers.

20. Anti-copy film according to claim 1 and 2 or 18 and one or more of claims 3 to 17 and 19, characterized gekennzeich¬ net that the angle of the connecting straight line between the ends of the width (dg) of superimposed covers (AI, A2 ) is in the range from approximately 30 ° to approximately 73 °, in particular approximately 45 ° to approximately 60 °.

21. Anti-copy film according to claim 1 or 18 and one or more of claims 2 to 17 and 19 and 20, characterized in that the at least one film or the at least one layer (S) is transparent with a transparent Carrier film (F) is connected.

22. Anti-copy film according to claim 21, characterized in that the thickness of the carrier film (F) is at least 70% of the thickness

(s) of the film or layer (S).

23. Anti-copying film according to one or more of claims 1 to 22, characterized in that the thickness (s) of the film or layer (S) is of the order of magnitude of approximately 5 μ, in particular approximately 20 μ up to about 100 μ.

24. Anti-copy film according to claim 21, characterized in that the thickness (s) of the film or layer (S) corresponds approximately to the thickness (h) of the carrier film (F).

25. Anti-copy film according to claim 1 or 18, and one or more of claims 2 to 17 and 19 to 24, characterized gekenn¬ characterized in that the at least partially opaque covers (AI, AI ', A2, A2 ') have a substantially strip shape (ST) and are arranged approximately parallel and equally spaced from one another.

CHANGED REQUIREMENTS

[Received at the International Bureau on January 10, 1994 (January 10, 1994), original claims 1-25 replaced by amended claims 1-12;

(2 pages)]

1. A process for the production of an anti-copying film, in which strip-like covers (AI; A2) which are opaque on both sides are applied to a transparent film (S) in a uniformly repeating manner and in a defined manner offset from one another, characterized in that the covers (AI-A2) in the defined staggered arrangements on the film (S) in terms of printing technology and / or phototechnology by applying a photosensitive layer (B1) on one side of the film (S), exposing the layer through a mask (MI) and then Developing and applying another photosensitive layer (B2) on the other side of the film, exposing through a mask (M2) and then developing.

2. The method according to claim 1, characterized in that the further photosensitive layer (B2) is exposed through the first, already developed layer (B1).

3. The method according to claim 1, characterized in that on a transparent film (S) on the one hand a line structure (LS) and on the other hand a photosensitive layer (B) is applied, the photosensitive layer (B) through the Linien¬ structure (LS ) exposed through and then developed.

4. The method according to claim 1 to 3, characterized in that the exposure is carried out by means of parallel radiation, so that almost no overlap of the covers (AI, A2) is obtained.

5. The method according to claim 1 to 3, characterized in that the exposure takes place by means of divergent light radiation, so that essentially an overlap of the covers (AI ', A2') is obtained.

6. The method according to claim 1, characterized in that on a transparent film (S) on the one hand a negative resist layer (BN) and on the other side a positive resist layer (BP) are applied and by exposing both layers through a mask (M) from the side of the negative resist layer and washing out both layers (BN, BP) the covers are formed. 7. The method according to claim 1 to 6, characterized in that the photosensitive layer material is a photographic emulsion.

8. The method according to claim 1 to 6, characterized in that the photosensitive layer material is a plastic layer with photoinitiators.

9. The method according to claim 1, characterized in that a non-opaque layer material is made opaque prior to application, in particular by color mixing.

10. The method according to claim 1, characterized in that a non-opaque layer material after application,

Exposing and developing in the raised or recessed areas is provided with opaque material.

11. The method according to claim 1 to 10, characterized in that the finished layers are sealed with the covers by means of a transparent lacquer coating.

12. The method according to claim 1 to 11, characterized in that the first and second covers (AI; A2) of a width (dg) with a horizontal distance (do) between the first covers or between the second covers between 50 and 90th % of the width (dg) of the covers.