Document security system

• US 4,903,991 A
• Filed: 07/18/1983
• Issued: 02/27/1990
• Est. Priority Date: 07/18/1983
• Status: Expired due to Fees

• Current Assignee: Chillicothe Paper Incorporated (Verso Corporation)
• Original Assignee: MEAD Corporation (Meadwestvaco Corporation)
• Inventors: Wright, Richard F.
• Primary Examiner(s): Eley, Timothy V.
• Application Number:
  US06/514,406
• Time in Patent Office: 2,416 Days
• Field of Search: 428/916, 430/10, 430/138, 283/70, 283/74, 283/95, 283/901
• US Class Current: 283/95
• CPC Class Codes: B42D 25/29 Securities; Bank notes
• CPC Class Codes: Y10S 283/901 Concealed data

Abstract

A system for verifying the authenticity of documents such as negotiable instruments wherein a field of photoactive microcapsules is provided in a localized area on the document. By image-wise exposing the document, a latent image of a verification meand such as a signature, fingerprint, or the like can be produced on the document which can be instantly developed upon rupturing the microcapsules to verify the authenticity of the document when it is presented.

Claims

1. A document such as a bill of lading, a check, or the like, said document having markings indicative of a bill of lading, a check, or the like and having a field of microcapsules on at least one surface thereof in a localized area, said microcapsules containing an internal phase including a radiation sensitive composition which undergoes a change in viscosity upon exposure to actinic radiation, said field carrying a latent image in the form of an image-wise distribution of microcapsules which are capable of releasing said internal phase upon rupturing, wherein said latent image is suitable for verifying the authenticity of said document or the signatures thereon, said latent image being produced in said field of microcapsules by image-wise exposing said field to actinic radiation and the authencity of said document being verifiable by rupturing said microcapsules and developing said latent image.

2. The documents of claim 1, wherein said microcapsules have discrete microcapsule walls.

3. The document of claim 2 wherein said microcapsules have associated therewith an image-forming agent which is image-wise mobilized by said internal phase upon rupturing said microcapsules.

4. The document of claim 3 wherein said image forming agent is a substantially colorless color former of the electron donating type which reacts with a color developer of the electron accepting type to produce a color image.

5. The documents of claim 4 wherein said color developer is present on said document in said localized area with said microcapsules.

6. The document of claim 5 wherein said radiation sensitive composition includes a polyethylenically unsaturated compound and a photoinitiator.

7. The document of claim 4 wherein said latent image is an image of an identification number, a signature, or a likeness of a person authorized to negotiate said document.

8. The document of claim 4 wherein said color developer is provided on a developer sheet and said latent image is developed by image-wise transferring said color former to said developer sheet.

9. The document of claim 3 wherein said latent image is developed by rupturing said microcapsules and applying a toner to said field, said toner being one which selectively adheres to said field in the areas in which said internal phase is released.

10. The document of claim 3 wherein said image-forming agent is a visible dye and said latent image is developed by rupturing said microcapsules in contact with a sheet to which said dye is image-wise transferred.

11. The document of claim 1 wherein said radiation sensitive composition is sensitive to non-ambient radiation.

12. A process for verifying the authenticity of a document wherein said document has markings thereon indicative of a check, bill of lading or the like and carries a field of microcapsules on at least one face thereof in a localized area, said microcapsules containing an internal phase including a radiation sensitive composition which undergoes a change in viscosity upon exposure to actinic radiation, said process comprising:

image-wise exposing said field of microcapsules to actinic radiation so as to produce a latent image in said field which is useful in verifying the authenticity of said document, said latent image being an image-wise distribution of microcapsules capable of releasing said internal phase upon their rupture,

rupturing said microcapsules and developing said latent image so as to produce a visible image from which the authenticity of said document can be verified, and

verifying the authenticity of said document.

13. The process of claim 12 wherein an image-forming agent is associated with said field of microcapsules which is image-wise mobilized by said internal phase when said microcapsules are ruptured.

14. The process of claim 13 wherein said image-forming agent is a substantially colorless color precursor of the electron donating type which reacts with a color developer of the electron accepting type to form a color image.

15. The process of claim 14 wherein said color developer is present on said document in said field with said microcapsules.

16. The process of claim 15 wherein said color developer is present in a layer underlying said layer of microcapsules such that said color developer reacts with said color former in the areas in which said internal phase is released from said microcapsules.

17. The process of claim 14 wherein said color developer is provided on a developer sheet and (said latent image) is developed by contacting said document with said developer sheet in the area of said field and thereby image-wise transferring said color former to said developer sheet and forming an image from which the authenticity of said instrument can be verified.

18. The process of claim 13 wherein said image-forming agent is a visible dye or pigment and (said latent image) is developed by contacting said document in the area of said field with a sheet to which said dye or pigment, mobilized by said internal phase, transfers and forms an image from which the authenticity of said document can be verified.

19. The process of claim 12 wherein (said latent image) is developed by applying a toner to said document in the area of said field, said toner adhering to said field in the areas in which said internal phase is released from said microcapsules.