SECURITY READER FOR AUTOMATIC DETECTION OF TAMPERING AND ALTERATION

• US 20060139622A1
• Filed: 03/01/2006
• Published: 06/29/2006
• Est. Priority Date: 10/06/1993
• Status: Active Grant

• Current Assignee: Thales DIS France SA
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Mann, Graeme R.
• Granted Patent: US 7,821,621 B2
• Time in Patent Office: Days
• US Class Current: 356/71
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: G06K 19/06046 Constructional details
• CPC Class Codes: G06K 19/14 the marking being sensed by radiation
• CPC Class Codes: G06K 7/10574 Multiple sources

Abstract

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). The light turning properties of the mirror (23) produce a light source which appears to an image receiver (40) as being returned from the surface of the document (10) at an angle of less than 1°. The image receiver (40) passes a signal via line (32) to a personal computer (41) which processes the received information. Such processing is to establish whether the document (10) includes a retroreflective laminate, a plain polyester laminate, or neither. Additionally, further processing can establish whether the document (10) has been tampered with, altered, or forged.

Claims

1. A method for recovering an image from a document having an image, the method comprising the steps of:

(a) providing a document having an at least partially light-transmissive first layer, the first layer including at least one image;

(b) illuminating the image with a light source;

(c) recovering the image with a video image receiver to provide a source image;

(d) comparing the source image with at least one stored image that is stored in a computer; and

(e) providing an output signal comprising information about the source image.

2. A method according to claim 1 where in the light source emits light within the visible portion of the spectrum.

3. A method of claim 1, where in the light source emits light within the infrared portion of the spectrum.

4. The method of claim 1, wherein the light source emits polarized light.

5. The method of claim 1, wherein the method further comprises (f) sending the output signal to a personal computer.