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AssigneeEcole Polytechnique Federale de Lausanne
InventorsIsaac Amidror, Roger D. Hersch
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This invention discloses new methods, security devices and apparatuses for authenticating documents and valuable articles which may be applied to any support, including transparent synthetic materials and traditional opaque materials such as paper. The invention relates to moire intensity profiles which occur in the superposition of periodic or aperiodic geometrically transformed structures. By using a specially designed basic screen and master screen, where at least the basic screen is comprised in the document, a moire intensity profile of a chosen shape becomes visible in their superposition, thereby allowing the authentication of the document. If a microlens structure is used as a master screen, the document comprising the basic screen may be printed on an opaque reflective support, thereby enabling the visualization of the moire intensity profile by reflection. Automatic document authentication is supported by an apparatus comprising a master screen, an image acquisition means such as a camera and a comparing processor whose task is to compare the acquired moire intensity profile with a reference image. Depending on the match, the document handling device connected to the comparing processor accepts or rejects the document. An important advantage of the present invention is that it can be incorporated into the standard document printing process, so that it offers high security at the same cost as standard state of the art document production.
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
An apparatus for authentication of documents making use of at least one moire intensity profile, the apparatus comprising:
A method for authenticating documents by using at least one moire intensity profile, the method comprising the steps of:
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where the basic screen is a multichromatic basic screen whose individual elements are colored, thereby generating a color moire image when the master screen is superposed on said basic screen.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen includes dots whose shapes gradually vary according to their position, thereby generating in the screen superposition moire intensity profiles which vary in their shapes according to their position.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen includes dots whose colors gradually vary according to their position, thereby generating in the screen superposition moire intensity profiles which vary in their colors according to their position.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen includes dots of gradually varying shapes and is incorporated within a variable intensity halftoned image.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen is an aperiodic screen.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen is obtained by perforation.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen is obtained by etching.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where the document is a valuable product.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where the document is a package of a valuable product.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where the document is affixed to a valuable product.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where at least one screen selected from the set comprising the basic screens and the master screen is located on a valuable product, and where at least one other screen selected from the same set is located on the valuable product's package.
A security document protected by a security device, said security device comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, where said security document is an optical disk.
A security document protected by a security device, said security device comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the refection of the document depending on the result of the comparison, where said security document is a package of a valuable product.
A security device for authentication of documents comprising at least one basic screen with at least one basic screen dot shape, that is located on the document, where the document authentication is done by superposing a master screen with a master screen dot shape and a basic screen, thereby producing a moire intensity profile and permitting the comparison of said moire intensity profile with a reference moire intensity profile and the acceptance or the rejection of the document depending on the result of the comparison, and where the basic screen is created by an embossing process and the master screen is selected from the set comprising pinhole screens, screens containing tiny dots and microlens structures.
Dependencies are inferred from the claim text.