Electro-optic displays, and processes for the production thereof

Patent metadata

Field	Value
Publication number	US-9835925-B1
Application number	US-201614989031-A
Country	US
Kind code	B1
Filing date	Jan 6, 2016
Priority date	Jan 8, 2015
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

Improvements in the production of electro-optic displays include: (a) use of a masking film to keep a selected area of a backplane (such as a front electrode contact) free from electro-optic material; (b) spray coating of electrophoretic capsules on to a substrate under controlled conditions; (c) forming a monolayer of capsules on a substrate by prior deposition of a water-swellable polymer; and (d) overcoating a layer of electro-optic material with a solvent-free polymerizable liquid material, contacting this layer with a light-transmissive electrode layer, and polymerizing the liquid material to adhere the electrode layer to the electro-optic material.

First claim

The invention claimed is:

1. A process for producing a sub-assembly for use in an electro-optic display, the process comprising:
providing a backplane comprising at least one electrode located in a first area of the backplane;
covering a second area of the backplane spaced from the electrode with a masking layer;
coating the backplane having the masking layer thereon with a layer of an electro-optic material; and
removing the masking layer, and the electro-optic medium thereon, from the backplane, thereby producing a sub-assembly comprising the backplane having its first area covered by the layer of electro-optic material but its second area free from the layer of electro-optic material.

2. A process according to claim 1 further comprising providing a light-transmissive conductive layer; covering part of the light-transmissive conductive layer with a lamination adhesive, and thereafter laminating the light-transmissive conductive layer and lamination adhesive to the sub-assembly with the lamination adhesive contacting the electro-optic material and the light-transmissive conductive layer in electrical contact with the contact on the backplane.

3. A process according to claim 1 wherein after the layer of electro-optic material has been coated on the backplane, but before the masking layer is removed, a layer of lamination adhesive is coated over the electro-optic material, and then the masking layer is removed, together with electro-optic material and the lamination adhesive thereon.

4. A process according to claim 3 further comprising laminating a light-transmissive electrically-conductive layer to the lamination adhesive in the first area of the backplane; the light-transmissive electrically-conductive layer extending into the second area of the backplane and making electrical contact with a contact pad in this second area.

5. A process according to claim 1 wherein the backplane has a third area, and the process further comprises covering the third area by a second masking layer which can be removed separately from the masking layer covering the second area, and wherein, after the layer of electro-optic material has been coated, the second masking layer is removed, thus exposing the third area of the backplane.

6. A process according to claim 1 wherein the electro-optic material comprises an encapsulated electrophoretic material or a polymer-dispersed electrophoretic material.

7. A process for spraying capsules of an electrophoretic medium on to a substrate, the process comprising:
forming a dispersion of the capsules in a liquid;
feeding the dispersion through a first orifice; and
feeding a continuous stream of gas through a second, annular orifice surrounding the first orifice, thereby forming a spray of the capsules,
wherein, during spraying of the capsules, a masking material covers part of the substrate, and after the spraying the masking material and the capsules thereon are removed so that, after removal of the masking material, capsules remain only on those portions of the substrate where the masking material was not present.

8. A process for forming an electro-optic display, the process comprising:
providing a backplane comprising at least one electrode;
coating the backplane with a layer of an electro-optic material;
depositing a layer of a substantially solvent-free polymerizable liquid material over the layer of electro-optic material;
contacting the polymerizable liquid material with at least one light-transmissive electrically-conductive layer; and
exposing the polymerizable liquid material to conditions effective to cause polymerization of the material, thereby adhering the at least one light-transmissive electrically-conductive layer to the layer of electro-optic material.

9. A process according to claim 8 wherein the electrode is located in a first area of the backplane, and the coating of the backplane with the layer of electro-optic material is effected by:
covering a second area of the backplane spaced from the electrode with a masking layer;
coating the backplane having the masking layer thereon with the layer of the electro-optic material; and
removing the masking layer, and the electro-optic medium thereon, from the backplane.

10. A process according to claim 8 wherein the coating of the backplane with the layer of electro-optic material is effected by:
forming a dispersion of the capsules in a liquid;
feeding the dispersion through a first orifice; and
feeding a continuous stream of gas through a second, annular orifice surrounding the first orifice, thereby forming a spray of the capsules.

11. A process according to claim 8 wherein both a light-transmissive electrically-conductive layer and a color filter array are adhered to the electro-optic layer.

12. A process according to claim 8 wherein the electro-optic material comprises an encapsulated electrophoretic material or a polymer-dispersed electrophoretic material.

13. A process according to claim 12 wherein the electro-optic material comprises an encapsulated electrophoretic material and the material used to apply the electrophoretic material to the backplane comprises a surfactant.

14. A process according to claim 8 wherein the backplane is coated with a surfactant or a polyurethane latex prior to coating of the electro-optic material thereon.

Assignees

• E Ink Corp

Inventors

• Bull Stephen
• Brewer Damien
• Anseth Jay William
• Paolini Jr Richard J
• Fauvell Thomas
• Harris George G
• Regan Michael Thomas

Classifications

• G02F2001/133354

  Physics · mapped topic

• G02F1/153 Primary

  Constructional details · CPC title

• G02F1/167 Primary

  by electrophoresis · CPC title

• B05D7/54

  No clear coat specified · CPC title

• G02F1/16757

  Microcapsules · CPC title