DISPLAY DEVICE

• US 3,617,374 A
• Filed: 04/14/1969
• Issued: 11/02/1971
• Est. Priority Date: 04/14/1969
• Status: Expired due to Term

• Current Assignee: Eurand America Incorporated
• Original Assignee: Joe W. Jones, John G. Whitaker, Theodore L. Hodson
• Inventors: Hodson, Theodore L., Whitaker, John G., Jones, Joe W.
• Primary Examiner(s): Leavitt, Alfred L.
• Assistant Examiner(s): Grimaldi, Alan
• Application Number:
  US04/815,966
• Time in Patent Office: 932 Days
• Field of Search: 117/212,215,217,226 73/356 161/410 252/408
• US Class Current: 349/19
• CPC Class Codes: C09K 2323/06 Substrate layer characterised by chemical composition
• CPC Class Codes: G01D 7/005 Indication of measured value by colour change
• CPC Class Codes: G02F 1/132 Thermal activation of liquid crystals exhibiting a thermo-optic effect
• CPC Class Codes: G02F 1/1334 based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
• CPC Class Codes: Y10T 428/249996 Ink in pores

Abstract

The present disclosure is directed to articles of manufacture, e.g., display devices, having self-contained controlled resistor means for generation of heat upon electrical activation, which means can be formed in any desired configuration and thickness, and an encapsulated liquid crystal layer responsive to variations in heat to present a display, which can be polychromatic. The resistor is comprised of conductive ink deposited on one major surface (usually the lower surface) of an opaque, substantially electrically nonconductive layer having a layer of encapsulated cholesteric liquid crystals in direct contact with at least a portion of the other major (e.g., upper) surface of the opaque layer. Heating due to the resistor produces reversible color changes in the encapsulated liquid crystals resulting in the display.

Claims

2. A display article as in claim 1 wherein the display configuration is substantially the same as at least a portion of the configuration of the conductive ink layer.

3. A display article as in claim 1 wherein the display configuration is substantially the same as at least a portion of the configuration of the encapsulated liquid crystal layer.

4. A display article as in claim 1 wherein said opaque layer is black.

5. A display article as in claim 1 wherein said encapsulated liquid crystal layer contains encapsulated liquid crystals having different color-temperature responses.

6. A display article as in claim 1 wherein encapsulated liquid crystals having different color-temperature responses are employed in different areas of said encapsulated liquid crystal layer.

7. A display article as in claim 1 wherein said encapsulated liquid crystal layer has a substantially smooth, essentially transparent, display brightness-improving top layer.

8. A display article as in claim 2 wherein said conductive ink layer is comprises of a plurality of unconnected portions at least some of which function independently from a remaining portion when electrically activated to generate heat.

9. A display article as in claim 2 wherein said conductive ink contains carbon black.

10. A display article as in claim 3 wherein said encapsulated liquid crystal layer is comprised of a plurality of unconnected portions.