SECURITY READER FOR AUTOMATIC DETECTION OF TAMPERING AND ALTERATION

A document (10) is covered by a laminate (13) comprising a layer of microspheres (16) over an adhesive layer (14) covering a source image (12) such as a photograph, printed matter, or a bar code arranged on a substrate (11). Light impinging on the document (10) is split by the optical properties of the microspheres (16) and underlying specular reflectors. The remaining light passes through the microspheres (16), through the adhesive layer (14) and strikes the substrate (11) or source image (12) on the document (10), and is reflected (18) and scattered (20). Alternatively, the laminate (13) can comprise a plain or clear layer of polyester without microspheres over the adhesive layer (14). Light impinging on the laminate (13) passes through the polyester and laminate (14) to strike the substrate (11) or source image (12) where it is reflected and scattered. A first light source (24) directs light to the document (10). A second light source (26,27) directs light towards a beam splitting mirror (23) which reflects the light to the document (10).