ENCAPSULATED CHOLESTERIC LIQUID CRYSTAL DISPLAY DEVICE

• US 3,585,381 A
• Filed: 04/14/1969
• Issued: 06/15/1971
• Est. Priority Date: 04/14/1969
• Status: Expired due to Term

• Current Assignee: Eurand America Incorporated
• Original Assignee: Donald Churchill, James V. Cartmell, Joe W. Jones, Theodore L. Hodson
• Inventors: Hodson, Theodore L., Cartmell, James V., Churchill, Donald, Jones, Joe W.
• Application Number:
  US04/815,662
• Time in Patent Office: 792 Days
• US Class Current: 349/21
• CPC Class Codes: B41M 5/281 using liquid crystals only
• CPC Class Codes: C09K 19/544 as dispersing or encapsulating medium around the liquid crystal
• CPC Class Codes: G02F 1/132 Thermal activation of liquid crystals exhibiting a thermo-optic effect
• CPC Class Codes: G11C 13/048 using other optical storage elements
• CPC Class Codes: Y10S 428/913 Material designed to be responsive to temperature, light, moisture
• CPC Class Codes: Y10T 428/239 Complete cover or casing
• CPC Class Codes: Y10T 428/249997 Encapsulated liquid

Abstract

The present disclosure is directed to articles of manufacture, e.g., display devices, having an encapsulated liquid-crystal member of enhanced color purity, color contrast and visual resolution due to an overlying essentially transparent top layer having a substantially smooth exterior surface. This essentially transparent layer has an index of refraction which approximates that of the capsule cell wall material and any polymeric or other binder used in conjunction with the encapsulated liquid crystals in the encapsulated liquid crystal layer or member.

Claims

2. An article as in claim 1 wherein at least one electrically conductive resistor heater element is in thermally responsive communication with a portion oF said encapsulated cholesteric liquid crystals.

3. An article as in claim 1 wherein said capsules have diameters ranging from about 5 to about 500 microns.

4. An article as in claim 1 wherein said top layer is inorganic.

5. An article as in claim 1 wherein said top layer is an organic plastic.

6. An article as in claim 5 wherein said organic plastic is a polyester. 7. An article of manufacture comprising an encapsulated cholesteric liquid crystal layer comprised of a profusion of cholesteric liquid crystal capsules in a binder having an opaque background layer on one surface and a substantially smooth, essentially transparent top layer of substantially the same thickness throughout on the other surface thereof, the interior portion of said top layer being in direct contact with said encapsulated cholesteric liquid crystal layer throughout substantially the entire extent thereof, wherein the index of refraction of said binder, top layer and the capsule cell wall material ranges from about 1.40 to about 1.70.

8. An article as in claim 7 wherein said top layer is glass.

9. An article as in claim 7 wherein said top layer is plastic.

10. An article as in claim 9 wherein said plastic is a polyester.

11. An article as in claim 10 wherein said polyester is polyethylene glycol terephthalate.

12. An article as in claim 9 wherein said plastic is polystyrene.

13. An article of manufacture comprising a substrate having an opaque background layer, an encapsulated cholesteric liquid crystal layer overlying said substrate and a substantially smooth, essentially transparent top layer overlying said encapsulated cholesteric liquid crystal layer, the interior portion of said top layer being in direct contact with said encapsulated cholesteric liquid crystal layer throughout substantially the entire extent thereof wherein said encapsulated cholesteric liquid crystal layer is comprised of a profusion of cholesteric liquid crystal capsules in a polymeric binder and the index of refraction of said binder, top layer and the capsule cell wall material ranges from about 1.40 to about 1.70

14. An article of manufacture as in claim 13 wherein said substrate is paper.

15. An article of manufacture as in claim 13 wherein said substrate is plastic.