Chromogenic Media Responsive to Environmental Conditions

• US 20080004176A1
• Filed: 06/29/2006
• Published: 01/03/2008
• Est. Priority Date: 06/29/2006
• Status: Active Grant

• Current Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Original Assignee: Lexmark International Incorporated (Ninestar Corporation)
• Inventors: Rosa, Dell T., Cullen, Philip Michael, Samuels, Louann Behymer
• Granted Patent: US 7,919,433 B2
• Time in Patent Office: Days
• US Class Current: 503/200
• CPC Class Codes: B41M 5/20 using electric current B41M5/24 takes precedence ; processes in which the current is transformed into a heat pattern for obtaining transfer to a receptor sheet B41M5/382; electro-coagulable or electro-adhesive printing or recording B41C1/105
• CPC Class Codes: B41M 5/282 using thermochromic compounds
• CPC Class Codes: B41M 5/34 Multicolour thermography

Abstract

The present invention relates to chromogenic material that may respond and shift in color due to environmental conditions such as heat, light or humidity. The light may include both visible and non-visible light, such as ultraviolet light. The chromogenic material may therefore provide a method to independently develop a latent image on a given substrate, and in particular, to a substrate that includes conventional thermosensitive image forming media.

Claims

1. A medium capable of developing a latent image comprising:

a substrate having surface, wherein said surface includes a first chromogenic material providing a first image; and

a second chromogenic material capable of providing a secondary image wherein said secondary image is capable of developing upon exposure to an environmental condition.

2. The medium of claim 1 wherein said secondary image, prior to exposure to said environmental condition, is transparent relative to said first image.

3. The medium of claim 1 wherein said environmental condition renders said first image as illegible.

4. The medium of claim 1 wherein upon exposure to said environmental condition, said first chromogenic material is capable of undergoing a color change and said secondary image is capable of undergoing a color change that contrasts with said first chromogenic material color change.

5. The medium of claim 1 wherein said environmental condition comprises exposure to heat, light, electric, solvent, ions, pH change, mechanical friction, mechanical pressure, or combinations thereof.

6. The medium of claim 1 wherein said first image is formed from a thermochromic ink, dye, paint and/or pigment.

7. The medium of claim 1 further comprising an adhesive on said substrate.

8. The medium of claim 1 wherein said second chromogenic material is a thermochromic and/or photochromic ink, dye, paint, and/or pigment.

9. The medium of claim 1 wherein said first image is thermally printed.

10. The medium of claim 1 wherein said secondary image covers all, none, or a portion of said first image.

11. The medium of claim 1, further comprising a non-chromogenic material capable of providing an image, wherein said non-chromogenic material, prior to exposure to said environmental condition, is transparent relative to said first image.

12. The medium of claim 1 in the form of a pharmaceutical label.

13. A medium capable of developing a latent image comprising:

a substrate having a surface, wherein said surface includes a first chromogenic material providing a first image and a second material comprising a non-chromogenic material;

said non-chromogenic material capable of providing a secondary image on said substrate when said first chromogenic material is exposed to an environmental condition.

14. The medium of claim 13 further comprising a mixture of said non-chromogenic material and a second chromogenic material, wherein said mixture, prior to exposure to said environmental condition, is transparent relative to said first image.

15. The medium of claim 13 wherein said non-chromogenic material, prior to exposure to said environmental condition, is transparent relative to said first image.

16. The medium of claim 13 wherein upon exposure to said environmental condition, said first chromogenic material is capable of undergoing a color change and said secondary image contrasts with said first chromogenic material color change.

17. The medium of claim 13 wherein said environmental condition comprises exposure to heat, light, electric, solvent, ions, pH change, mechanical friction, mechanical pressure or combinations thereof.

18. The medium of claim 13 wherein said first image is formed from a thermochromic ink, dye, paint and/or pigment.

19. The medium of claim 13 wherein said first image is thermally printed.

20. The medium of claim 13 in the form of a pharmaceutical label.

21. The method of developing a latent image upon exposure to an environmental condition, comprising:

providing a substrate have a surface, wherein said surface contains a first chromogenic material capable of forming a first image;

applying a second chromogenic material wherein said second chromogenic material is capable of forming a secondary image upon exposure to an environmental condition, wherein said environmental condition is capable of rendering said first image as illegible.