Method for authenticating packages using magnetophoretic imaging films

• US 10,649,247 B2
• Filed: 09/06/2019
• Issued: 05/12/2020
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: E Ink Holdings Incorporated
• Original Assignee: E Ink California, LLC (E Ink Corporation)
• Inventors: Laxton, Peter B.
• Primary Examiner(s): Thomas, Brandi N
• Application Number:
  US16/562,789
• Publication Number:
  US 20190391417A1
• Time in Patent Office: 249 Days
• Field of Search: 359237, 359245, 359265-267, 359290-292, 359295, 359296, 359298
• CPC Class Codes: B42D 25/369 Magnetised or magnetisable materials
• CPC Class Codes: G02F 1/09 based on magneto-optical elements, e.g. exhibiting Faraday effect
• CPC Class Codes: G02F 1/094 based on magnetophoretic effect

Abstract

The present invention is directed to a method for authenticating a package using a magnetophoretic imaging film. It provides a low-cost method for verifying the authenticity of products in a way that is not immediately evident to counterfeiters. A single pre-patterned magnetic image can be used to display images on any number of individual imaging films.

Claims

1. A method for authenticating a package comprising:

a) providing a package comprising a pre-generated magnetic pattern;

b) providing a magnetophoretic imaging film, the magnetophoretic imaging film comprising a substrate and a plurality of microcells or microcapsules contacting the substrate, the microcells or microcapsules containing a fluid having a viscosity of at least 50 cps, non-magnetic particles, and magnetic particles;

c) bringing the magnetophoretic imaging film in proximity to the pre-generated magnetic pattern; and

d) allowing a semi-permanent image of the pre-generated magnetic pattern to appear on the magnetophoretic imaging film.

2. The method of claim 1, wherein the image of the pre-generated magnetic pattern remains on the magnetophoretic imaging film after the magnetophoretic imaging film is moved away from the pre-generated magnetic pattern.

3. The method of claim 1, wherein the image of the pre-generated magnetic pattern disappears from the magnetophoretic imaging film after the magnetophoretic imaging film is moved away from the pre-generated magnetic pattern.

4. The method of claim 1, wherein the magnetic particles comprise magnetic metals or alloys.

5. The method of claim 4, wherein the magnetic particles are black.

6. The method of claim 4, wherein the magnetic particles comprise ferric oxides.

7. The method of claim 1, wherein the non-magnetic particles are white.

8. The method of claim 1, wherein the fluid comprises polymers and a solvent.

9. The method of claim 1, wherein an image of the pre-generated magnetic pattern is not visible on the package without the magnetophoretic imaging film.

10. The method of claim 1, wherein the fluid further comprises a rheology modifier having a molecular weight greater than 250 kDa.