Innovia Films Limited

Securency International Pty Ltd

Robert Stewart

Gary Fairless Power

Stephen Langstaff

Thierry Gavel

Steven Maude

Joshua Robert Nemeth

The present invention provides a method of authenticating the provenance of an article marked with a removable transparent polymer film comprising measuring the thickness of the removable transparent film while still located on the article or of a layer within the film while still located on the article by white light interferometry. Alternatively, or in addition, the method comprises measuring the birefringence of the removable transparent polymer film while still located on the article or of a layer within the film while still located on the article.

Authentication of articles by white light interferometry and birefringence

The present invention provides a security document and method of production thereof. The security document () comprises: a polymer substrate () having first () and second () surfaces; a security feature () formed in a region of at least one of said first and second surfaces of said polymer substrate; an opacifying layer () formed on at least a portion of at least one of said first and second surfaces of said polymer substrate; a printed design formed on at least a portion of said opacifying layer; and wherein said security feature is formed at least prior to said printed design being formed.

Security document

A method of authenticating a polymer film comprises measuring the thickness of a layer therein by white light interferometry and/or measuring the birefringence of a layer therein. The method, and devices to carry out the method, may be used in security applications, for example to test for counterfeit bank notes.

Method of authenticating a polymer film by thickness measurement with a white light interferometer

The present invention provides an authentication apparatus operative to determine the authenticity of a polymer film, comprising an optically-based birefringence measuring arrangement operative to measure a first effect influenced by a birefringence characteristic of said film from a first angle comprising a non-normal angle to a plane of said film, and at least one of: a second angle; and a third angle; and wherein said apparatus is operative to: compare a value, or range of values, representative of said first effect as measured from said first angle with a value, or range of values representative of a specified first effect corresponding to a predetermined birefringence characteristic of an authentic polymer film for said first angle; compare a value, or range of values, representative of said first effect as measured from said at least one of said second and third angles with a value, or range of values representative of a specified first effect corresponding to a predetermined birefringence characteristic of an authentic polymer film for respective second and/or third angles; and output an authenticity signal indicative of authenticity or otherwise of said film based upon said comparisons. There are also provided one or more methods of determining the authenticity of a polymer film.

Authentication apparatus and method

The present invention provides an authentication apparatus operative to determine the authenticity of a polymer film, comprising: an optical response modifier operative to modify a first effect influenced by said birefringence characteristic of said to a modified first effect; and an optically-based birefringence measuring arrangement operative to measure said modified first effect; and wherein said apparatus is operative to: compare a value, or range of values, representative of said modified first effect as measured with a value, or range of values representative of a specified first effect as modified by a same optical response modifier and corresponding to a predetermined birefringence characteristic of an authentic polymer film; and output an authenticity signal indicative of authenticity or otherwise of said film based upon said comparison. There are also provided one or more methods of determining the authenticity of a polymer film.

The present invention provides an apparatus for detecting presence or otherwise of an item comprising at least two regions having different optical characteristics, said apparatus comprising: an emitter operative to illuminate a measuring region of said apparatus with electromagnetic radiation; and a detector located and operative to receive electromagnetic radiation reflected from said measuring region of said apparatus and operative to output a signal corresponding to a measured characteristic of said electromagnetic radiation reflected from said measuring region, wherein said apparatus is operative to compare said measured characteristic with a set of pre-defined characteristics, and further wherein if said measured characteristic is consistent with at least one of said pre-defined characteristics, the apparatus is operative to output a signal indicative of presence or otherwise of one of said at least two regions of said item in said measuring region. Also provided is a method for detecting presence or otherwise of an item comprising at least two portions having different optical characteristics, and a banknote counting apparatus comprising the detection apparatus and operative to implement the method.

Detection of the presence of an item using reflection characteristics

An authentication apparatus operative to determine the authenticity of an item comprising a film substrate responsive to detection that a portion of said item located in a measuring region of said apparatus has a predetermined birefringence characteristic, said apparatus comprising: an item detection arrangement operative to determine if at least a portion of an item is located in a measuring region of said authentication apparatus; and an optically-based birefringence measuring apparatus, wherein said authentication apparatus is operative to compare a measured birefringence characteristic with a predetermined birefringence characteristic and to produce an authenticity signal indicative of authenticity or otherwise of said item based upon said comparison, said apparatus further comprising a control means operative to control output of said authenticity signal from said apparatus responsive to determination, by said item detection arrangement, of presence or otherwise of said at least a portion of said item in said measuring region.

A method of producing a security document or article including a substrate (), which is transparent at least to visible light, and a diffractive optical microstructure (). The method includes applying an opacifying layer () to at least one surface of the transparent substrate (). An area of the opacifying layer () is exposed to laser radiation () to ablate apertures () in selected portions of the opacifying layer (), thereby forming a diffractive optical microstructure () on the surface of the substrate (). The laser radiation may be patterned prior to exposing the opacifying layer (), for example by passing the radiation through a mask (). Alternatively, a focussed or collimated laser beam () may be directed onto the selected portions of the opacifying layer (). Laser radiation may be directed onto the opacifying layer () either directly, or through the transparent substrate (). Security documents or articles made in accordance with the method are also provided.

Growing community of inventors

Wigton, United Kingdom

Robert Stewart