SECURITY DEVICE BASED ON CUSTOMISED MICROPRISM DEVICE

摘要

A security device comprises a transparent substrate (1 ) provided with a prismatic surface structure (2) defining an array of substantially planar facets. An adhesive layer (3) extends around the perimeter of one surface of the substrate (1) such that the security device can be adhered to a further substrate, wherein at least some parts of the said surface are exposed to the air whereby those parts will be spaced from the further substrate in use to define a transparent substrate/air interface such that corresponding parts of the prismatic surface structure (2) forms a reflector due to total internal reflection when viewed at at least one first viewing angle and are transparent when viewed at at least one second viewing angle.