Magnetophoretic display assembly and driving scheme

• US 10,444,553 B2
• Filed: 03/23/2015
• Issued: 10/15/2019
• 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:
  US14/666,040
• Publication Number:
  US 20150277160A1
• Time in Patent Office: 1,667 Days
• Field of Search: 359290-292, 359295, 359296, 359298, 359237, 359242, 359247
• 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 magnetophoretic display assembly and a driving scheme for such a display assembly. It provides a low-cost imaging display assembly which is capable of displaying desired re-writeable images. A single driving element can be used to display images on any number of individual imaging films.

Claims

1. A magnetophoretic display device, comprising:

a magnetic sheet having a magnetic pattern thereon,

and

a magnetophoretic imaging film comprising a substrate and a plurality of at least one of microcells and microcapsules applied to the substrate, the microcells and microcapsules containing a fluid, non-magnetic particles, and magnetic particles.

2. The device of claim 1, wherein said magnetic sheet comprises magnetic particles dispersed in a polymeric matrix.

3. The device of claim 1, wherein the magnetic sheet has a thickness in the range of 12 μ

m to 10 mm.

4. The device of claim 1, further comprising a pattern-generating means configured to generate the magnetic pattern in the magnetic sheet.

5. The device of claim 4, wherein the pattern-generating means is an electromagnet.

6. The device of claim 4, wherein the pattern-generating means is a stylus.

7. The device of claim 4, wherein the pattern-generating means is in the form of a stamp with a pre-determined pattern.

8. The device of claim 4, wherein the pattern-generating means is a magnet mounted on a computer controlled read-write head.

9. The device of claim 1, wherein the fluid comprises a solvent.

10. The device of claim 1, wherein the non-magnetic particles are white.

11. The device of claim 10, wherein the white non-magnetic particles are formed from an inorganic pigment.

12. The device of claim 10, wherein the white non-magnetic particles are polymer particles having a refractive index of >

1.5 and of a size of >

100 nm.

13. The device of claim 1, wherein the magnetic particles are formed from highly magnetic compounds and metals or alloys.

14. The device of claim 1, wherein the magnetic particles are formed from a material selected from the group consisting of gamma ferric oxide, acicular magnetite, cobalt-modified or adsorbed ferric oxide, berthollide ferric oxide, chromium dioxide, metals or alloys and organic polyradicals.

15. The device of claim 4, wherein the pattern-generating means is formed of a neodymium magnet.

16. A packaging in combination with a device according to claim 1, wherein the magnetic sheet is incorporated in the packaging and the packaging is configured such that the magnetophoretic imaging film forms an image of the magnetic pattern when applied to a surface of the packaging in proximity to the magnetic sheet.