Abstract: The tamperproof document consists of a photographic material as information carrier which is laminated on one or both sides with a transparent foil. The foil is attached to the surface of the information carrier by a layer of adhesive containing poly-1,2-alkyleneimine. The document is eminently saft against falsification.

Abstract: The tamper-proof document consists of a photographic material as information carrier comprising front- and back gelatine layers, the outer of the gelatine layers of which contain particles of a homo- or copolymer of an acrylic and/or methacrylic acid ester. The information carrier is laminated on one or both sides to a transparent foil by means of a hardenable adhesive. The document is remarkably safe against falsification.

Abstract: A card of size suitable for convenient carrying by a person, for example, in a billfold or wallet, the card having an information portion upon which information appears that can be read in the normal manner, a portion carrying microfilm upon which information is recorded, and a portion carrying a lens suitable for reading the microfilmed portion.

Abstract: Multi-ply laminae are provided which are suitable for use as tell-tale indicators for identification cards, credentials and the like. The laminae are post-laminated to a core layer bearing a photograph or similar information or indicia. Thereafter attempts to delaminate the card result in fibers being torn from a uniaxially oriented polyethylene or polypropylene layer of the laminae. Attempts to readhere the layers with adhesives result in tell-tale indicia in the form of the torn fibers which cannot be adequately realigned or adhered so as to be unnoticeable. Moreover, attempts to heat seal the card after tampering causes the oriented polymer to shrink and opacify resulting in additional tell-tale indicia of tampering. In addition, the core comprises heat seal surfaces upon which printing and other indicia is placed whereby any attempt to alter the printing or other indicia results in destruction of the card.

Abstract: A latent image identification card has a translucent base with a multiplicity of engraved scores extending through a generally opaque top layer into the base layer whereby a "negative" image appears when the background light is below a determinable value and a latent, "positive" image appears when the background light passing through the translucent base is above the determinable value.

Abstract: A verification device has a transparent sheet including parallel rows of lenticules and rows of colored lines in registration therewith. Verification is accomplished by observing optical effects presented by patterns of irregularly positioned rows of lenticules and corresponding colored lines viewed against a surrounding background area of regularly positioned rows of lenticules and corresponding colored lines.

Abstract: The invention teaches means for detecting unauthorized tampering or substitutions of a device, and has particular utility when applied on a "seal" device used to secure a location or thing. The seal has a transparent body wall, and a first indicia, viz., a label identification is formed on the inside surface of this wall. Second and third indicia are formed on the outside surface of the transparent wall, and each of these indicia is transparent to allow the parallax angled viewing of the first indicia through these indicia. The second indicia is in the form of a broadly uniform pattern, viz, many small spaced dots; while the third indicia is in the form of easily memorized objects, such as human faces, made on a substrate by means of halftone printing. The substrate is lapped over the outside surface of the transparent wall.

Abstract: A thermoplastic protective film for use in the manufacture of forgery-resistant identification documents, comprising a base layer and a cover layer comprising a partially hydrolyzed olefin/vinyl ester copolymer. The cover-layer side of the film is laminated under the action of heat to the identification document.