Anti-copy film layer for documents

Details Anti-copy film layer for documents Anti-copy film layer for documents

1995-02-13

1998-03-17

Krynski, William

Stock material or miscellaneous articles

Structurally defined web or sheet

Discontinuous or differential coating, impregnation or bond

428 29, 428198, 428203, 4284111, 4284884, 428913, 428914, 283 72, 283100, 283107, B32B 300

Patent

active

057284490

DESCRIPTION:

BRIEF SUMMARY
The present invention relates to an anti-copy film or layer for documents, comprising a film or layer of transparent material having a multiplicity of at least partially opaque areas, arranged at distances from one another and whose planes are arranged in approximately the same predefined position relative to the surfaces of the film or layer, so that the anti-copy film is essentially opaque at a viewing angle approximately perpendicular to the surfaces of the film or layer and is essentially transparent from a predefined viewing angle to the surfaces of the film or layer.
An anti-copy film of the abovementioned type is described in U.S. Pat. No. 3,887,742. A film of this type, which is intended to make copyproof documents possible, is effective in masking graphic information and/or symbols on a document or, generally, a paper in the vertical viewing direction, as in a photocopier, and rendering the graphic information and/or symbols visible at a predefined other viewing angle, relative to the plane of the document.
In practical terms, an anti-copy film of this type is a transparent plastic film containing opaque areas or having a surface which is notched in any desired manner or has a sawtooth profile in cross-section, in which a first inclined or perpendicular surface is either black or reflective with respect to a perpendicular viewing angle, relative to the plane of the film or document, and the other inclined surface is transparent at another viewing angle, so that the information or symbols are readable. Notched or sawtooth-profile sufaces of this type are extremely difficult to produce, since firstly the surfaces must be embossed or impressed, and then the inclined areas must be provided with a black or reflective material, it being necessary for the accuracy of these operations to be so high that the transparent areas are not affected, ie. are not also partly provided with black or reflective material. For the theoretical formation of inclined surfaces within the film, practical production details are not given.
An anti-copy medium for a written or printed material is disclosed in Australian Patent Application No. 610,614, in which the medium contains a photosensitive colorant system which renders the writing illegible on irradiation in a photocopier or makes the copy clearly differentiable from the original, so that either the original becomes worthless or becomes clearly recognisable as having been copied.
It is an object of the present invention to provide an anti-copy film or layer which is simpler to produce and is more economical.
We have found that this object is achieved by an anti-copy film or layer for documents, comprising a film or layer of transparent material having a multiplicity of at least partially opaque areas, arranged at distances from one another and whose planes are arranged in approximately the same predefined position relative to the surfaces of the film or layer, so that the anti-copy film or layer is essentially opaque at a viewing angle approximately perpendicular to the surfaces of the film or layer and the anti-copy film or layer is essentially transparent at a predefined viewing angle to the surfaces of the film or layer, wherein each of these at least partially opaque areas is formed from at least first opaque screens on one of the surfaces of the film or layer and at least second opaque screens on the remaining surfaces of the film or layer, and wherein the at least first and second screens are arranged essentially horizontally.
This significantly simplifies production of a film or layer of this type, which would otherwise have to be produced mechanically and/or chemically, and allows significant variations, depending on the intended use.
In practice, the first and second screens may be arranged parallel to one another, but offset, in horizontal planes.
In an expedient embodiment, the first and second screens can have the same width (in cross-section) and be arranged in a staggered, but substantially non-overlapping, manner.
However, it is also possible for the firs

REFERENCES:
patent: 3887742 (1975-06-01), Reinnagel et al.
patent: 4025673 (1977-05-01), Reinnagel et al.
patent: 4184700 (1980-01-01), Greenaway

Affiliated with

Also associated with

Rating

Anti-copy film layer for documents does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Anti-copy film layer for documents, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Anti-copy film layer for documents will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-955827