Illumination system for nonemissive electronic displays

• US 6,376,828 B1
• Filed: 10/07/1999
• Issued: 04/23/2002
• Est. Priority Date: 10/07/1998
• Status: Expired due to Term

• Current Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Original Assignee: E Ink Corporation (E Ink Holdings Incorporated)
• Inventors: Comiskey, Barrett
• Primary Examiner(s): LE, QUE TAN
• Application Number:
  US09/413,934
• Time in Patent Office: 929 Days
• Field of Search: 250/216, 250/227.11, 250/227.2, 250/227.24, 250/214.B, 250/214.AL, 345/7, 345/8, 345/9, 345/22, 345/23, 345/24, 345/25, 345/47, 345/48, 345/49
• US Class Current: 250/216
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0036 2-D arrangement of prisms, protrusions, indentations or roughened surfaces
• CPC Class Codes: G02B 6/0056 for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
• CPC Class Codes: G02F 1/133616 Front illuminating devices
• CPC Class Codes: G02F 1/167 by electrophoresis
• CPC Class Codes: G02F 1/16757 Microcapsules
• CPC Class Codes: G02F 1/1677 Structural association of cells with optical devices, e.g. reflectors or illuminating devices

Abstract

An illumination system for selectively illuminating a nonemissive electronic display comprises display elements in communication with at least one light source. The system comprises an nonemissive electronic display comprising a substrate having a first and a second surface, nonemissive display media having electrically responsive optical properties disposed on the first surface of the substrate, and a light transmissive element adjacent the second surface of the substrate. Light transmitted through the light transmissive element illuminates the display media. The invention also provides a tiled display comprising a plurality of substrates which can be selectively illuminated. The display elements can be tiled to create complex, selectively illuminated, three-dimensional display structures.

Claims

1. A reflective nonemissive electronic display, comprising:

a flexible substrate having a first surface and a second surface;

a flexible microencapsulated electrophoretic nonemissive display media adjacent the first surface of the flexible substrate; and

a flexible light transmissive element adjacent the second surface of the flexible substrate, wherein light transmitted through the light transmissive element illuminates the display media.

2. The reflective display of claim 1, wherein the light transmissive element is a light pipe.

3. The reflective display of claim 1, further comprising a light source in communication with the light transmissive element and wherein the light source transmits light through the light transmissive element.

4. The reflective display of claim 3, wherein the light source is selected from the group consisting of a cold cathode fluorescent lamp, an SMT incandescent lamp, and a light emitting diode.

5. The reflective display of claim 1, wherein the light transmissive element comprises a first face and a second face, the second face comprising a plurality of surface features.

6. The reflective display of claim 5, wherein the plurality of surface features are selected from the group consisting of wedge shapes, surfaces with triangular intrusions, ridges, or micro-roughened structures.

7. The reflective display of claim 3, wherein the light source is coupled to a photodetector.

8. The reflective display of claim 3, wherein the light source is activated when the level ambient light drops below a selected value.

9. A tiled display, comprising:

a plurality of flexible substrates, each substrate having at least a first and a second surface;

a display media adjacent the first surface of each of the flexible substrates; and

a flexible light transmissive element adjacent the second surface of at least one substrate, wherein light transmitted through the light transmissive element illuminates the display media.

10. The tiled display of claim 9, wherein the plurality of substrates forms a multicharacter display.

11. The tiled display of claim 9, comprising a plurality of light sources.

12. The tiled display of claim 9, further comprising a light source in communication with the light transmissive element and wherein the light source transmits light through the light transmissive element.

13. The tiled display of claim 12, wherein the light source is selected from the group consisting of a cold cathode fluorescent lamp, an SMT incandescent lamp, and a light emitting diode.

14. The tiled display of claim 9, wherein the light transmissive element is a light pipe.

15. The tiled display of claim 12, wherein a single light source illuminates at least two substrates.

16. The tiled display of claim 12, wherein the light source is coupled to a photodetector.

17. The tiled display of claim 12, wherein the light source is activated when the level of ambient light drops below a selected value.