De La Rue International Limited

De La Rue Holographics Limited

Ralph Kay

Brian William Holmes

Kenneth John Drinkwater

Charles E Chatwin

David Ezra

Marianne Michelle Anton

Keith A Jones

Adam J Silk

Martin C Gomme

An optically variable security device comprising a thin film reflection filter structure () which exhibits a first optically variable effect; and a relief structure () on or in the thin film reflection filter structure which exhibits a second optically variable effect.

Optically variable security device

A security device has a substrate formed with a surface relief defining an optically variable effect generating structure. At least two different reflection enhancing materials are provided on, or on the same side of, substrate with respect to the surface relief, whereby the optically variable effect can be viewed against a background defined by the reflection enhancing materials.

Security device

A security device comprises an optically variable effect generating structure ( ). An obscuring layer ( ) is located, in use, between the optically variable effect generating structure and a substrate ( ) to which the device is secured. A color layer ( ) is also included which exhibits one or more predetermined colors when viewed under certain viewing conditions from the side of the device remote from the obscuring layer. The obscuring layer ( ) is substantially opaque under the said certain viewing conditions.

A method of manufacturing a laminate structure for use in a security thread or tape comprises: i) providing a first structure ( ) having a flexible carrier ( ) supporting an optically variable effect structure ( ); ii) adhering the first structure ( ) to a flexible substrate ( ) with the optically variable effect structure ( ) between the carrier and the substrate; iii) removing the carrier ( ); iv) permanently bonding the carrier ( ) to the resulting laminate to generate a final laminate structure; and, v) slitting the laminate structure from step iv) into at least two lengths.

Manufacture of security tapes and security threads

A method of manufacturing a security device, the method comprising providing a radiation curable material on a shrinkable substrate; imparting an optically variable effect structure on or into the radiation curable material; and curing the material so that it retains the optically variable effect structure.

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Basingstoke, United Kingdom

Ralph Kay