Magnetophoretic display assembly and driving scheme
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.
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 μm 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.