Security papers

• US 4,183,989 A
• Filed: 11/29/1977
• Issued: 01/15/1980
• Est. Priority Date: 12/07/1976
• Status: Expired due to Term

• Current Assignee: Portals Ltd. (De La Rue PLC)
• Original Assignee: Portals Ltd. (De La Rue PLC)
• Inventors: Tooth, Alan J.
• Primary Examiner(s): Herbert, Jr., Thomas J.
• Application Number:
  US05/855,671
• Time in Patent Office: 777 Days
• Field of Search: 428/195, 428/208, 428/209, 428/900, 428/916, 427/7
• US Class Current: 428/195.1
• CPC Class Codes: D21H 21/44 Latent security elements, i.e. detectable or becoming apparent only by use of special verification or tampering devices or methods
• CPC Class Codes: D21H 21/48 Elements suited for physical verification, e.g. by irradiation
• CPC Class Codes: G07D 7/026 using capacitive sensors
• CPC Class Codes: G07D 7/04 Testing magnetic properties of the materials thereof, e.g. by detection of magnetic imprint G07D7/01 takes precedence
• CPC Class Codes: G07D 7/06 using wave or particle radiation
• CPC Class Codes: Y10S 428/90 Magnetic feature
• CPC Class Codes: Y10S 428/916 Fraud or tamper detecting
• CPC Class Codes: Y10T 428/24802 Discontinuous or differential coating, impregnation or bond [e.g., artwork, printing, retouched photograph, etc.]
• CPC Class Codes: Y10T 428/24909 Free metal or mineral containing
• CPC Class Codes: Y10T 428/24917 including metal layer

Abstract

A security paper which contains a security device e.g. a strip, thread or planchette having at least two machine verifiable security features thereon, one of which is a magnetic material, which may be magnetically coded or printed in a predetermined pattern on the device, and a second of which is a luminescent material, an X-ray absorbent or a metal. The provision of several features on one device provides a large increase in document security.

Claims

1. A security paper which contains a security device lying substantially within the body of the paper and having at least two distinct machine verifiable security features, a first of the security features being a magnetic material and the second feature being a second and different material selected from the group consisting of:

a. a luminescent material,

b. an x-ray absorbent, and

c. a non-magnetic metal.

2. A security paper as claimed in claim 1, wherein the security device contains a luminescent material selected from the group consisting of eosin, fluorescein, fluorspar, sulphate of quinine, fuchsin, calcium sulphide, Neodymium salicylate, Samarium gluconate or Yttrium salicylate.

3. A security paper as claimed in claim 1 wherein the magnetic material has variations in its magnetisation coded thereon.

4. A security paper as claimed in claim 1, wherein the security device comprises a plastics substrate having a magnetic powder layer thereon.

6. A security paper as claimed in claim 1, wherein the security device is a strip having at least one security feature printed in a predetermined pattern along the length thereof.

7. A security paper as claimed in claim 6 having the magnetic material and a luminescent material printed in register thereon.

5. A security paper as claimed in claim 44, wherein the non-metallic substrate has a layer of metal thereon, formed by a technique selected from the group consisting of vacuum deposition, laminating a metal foil to the plastics substrate film, and adhering a layer of metal powder to the plastics substrate film.

8. A security paper which contains a security device which is a strip of plastics film bearing as a first independently machine verifiable security feature a coating of a non-magnetic metal and as a second independently machine verifiable security feature a coating of a particulate magnetic material.

9. A process for making a security paper, which process comprises incorporating within the paper a security device which has at least two distinct machine verifiable security features, a first of the security features being a magnetic material and a second feature being selected from the group consisting of:

(a) a luminescent material,

(b) an X-ray absorbent, and

(c) a non-magnetic metal.

10. A method of verifying a security paper which paper contains a security device having at least two distinct security features which method comprises detecting by a machine a magnetic property of a magnetic material which is a first of the said security features and also detecting by a machine a second of the said security features by a property selected from the group consisting of:

(a) the luminescence of the security device,

(b) the absorption of X-rays by the security device, and

(c) the presence of non-magnetic metal in the security device.

11. A method as claimed in claim 10, wherein the presence of metal is detected by a property selected from the group consisting of the reflectivity of the metal to electromagnetic radiation and the effect of the metal on a balanced circuit selected from the group of balanced capacitative and inductive circuits.

12. A method as claimed in claim 10, wherein the magnetic property of the magnetic material is a property which varies in a predetermined manner along the length of an elongate security device.

13. A method as claimed in claim 12, wherein the variation of the magnetic property is detected and compared with a variation along the length of the security device of property selected from the group consisting of:

(a) the luminescence of the security device,

(b) the absorption of X-rays by the security device, and

(c) the presence of metal in the security device.