Reflective electrophoretic displays including photo-luminescent material and color filter arrays

Patent metadata

Field	Value
Publication number	US-11143929-B2
Application number	US-201916281530-A
Country	US
Kind code	B2
Filing date	Feb 21, 2019
Priority date	Mar 9, 2018
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

An electro-optic display is provided that may include a layer of light-transmissive conductive material, a substrate, a layer of an electro-optic medium disposed between the layer of conductive material and the substrate, a color filter array, and a light emitting layer. The electro-optic medium may include a photo-luminescent material that functions as either a down-converter or an up-converter that may be excited by the light received from the light emitting layer. The photo-luminescent material may be excited by radiation having a first wavelength transmitted by a filter within the color filter array and emit radiation having a second wavelength transmitted by the filter. The photo-luminescent material may also be excited by radiation at a wavelength within a first and second range of wavelengths transmitted by two filters within the color filter array and emit radiation at a wavelength within one of the first and second ranges.

First claim

We claim:

1. An electro-optic display comprising
a layer of light-transmissive conductive material,
a substrate,
a layer of an electro-optic medium disposed between the layer of light-transmissive conductive material and the substrate, the electro-optic medium comprising a dispersion of electrophoretic particles in a non-polar solvent and a photo-luminescent material, and
a color filter array,
wherein the photo-luminescent material is excited by radiation at a first wavelength and emits radiation at a second wavelength, the second wavelength being longer than the first wavelength, wherein the color filter array is between the layer of light-transmissive conductive material and the layer of electro-optic material.

2. The electro-optic display of claim 1 , wherein the photo-luminescent material is excited by light having a wavelength less than 450 nm and emits visible light having a wavelength greater than or equal to 450 nm.

3. The electro-optic display of claim 1 , wherein the photo-luminescent material is selected from the group consisting of a phosphorescent material, a fluorescent material, and quantum dots.

4. The electro-optic display of claim 1 , wherein the photo-luminescent material emits light at a wavelength from 450 to 490 nm.

5. The electro-optic display of claim 1 , wherein the color filter array is between the substrate and the layer of electro-optic material.

6. The electro-optic display of claim 1 , wherein the substrate comprises a plurality of conductive electrodes.

7. The electro-optic display of claim 6 , wherein the plurality of conductive electrodes form the color filter array.

8. The electro-optic display of claim 1 , wherein the electrophoretic particles comprises a plurality of black particles and a plurality of white particles.

9. The electro-optic display of claim 8 , wherein the white particles comprise the photo-luminescent material.

10. The electro-optic display of claim 8 , wherein the pluralities of black and white particles are charged and the black particles have a charge polarity that is opposite to a charge polarity of the white particles.

11. The electro-optic display of claim 10 , wherein the charged white particles comprise the photo-luminescent material.

12. The electro-optic display of claim 1 further comprising a light emitting layer, wherein the display is configured such that the photo-luminescent material is excited by light emitted by the light emitting layer.

13. An electro-optic display comprising
a layer of light-transmissive conductive material,
a substrate,
a layer of an electro-optic medium disposed between the layer of light-transmissive conductive material and the substrate, the electro-optic medium comprising at least one photo-luminescent material, and
a color filter array comprising a first color filter configured to transmit radiation within a first range of wavelengths and a second color filter configured to transmit radiation within a second range of wavelengths,
wherein the photo-luminescent material is excited by radiation at a wavelength within both of the first and second ranges and the photo-luminescent material emits radiation at a wavelength within one of the first and second ranges.

14. The electro-optic display of claim 13 , wherein the photo-luminescent material is selected from the group consisting of a phosphorescent material, a fluorescent material, and quantum dots.

15. The electro-optic display of claim 13 , wherein the photo-luminescent material is excited by radiation at a wavelength from 470 to 520 nm and emits radiation at a wavelength of 520 to 560 nm.

16. The electro-optic display of claim 13 , wherein the photo-luminescent material is excited by radiation at a wavelength from 560 to 635 nm and emits radiation at a wavelength of 635 to 700 nm.

17. The electro-optic display of claim 13 , wherein the electro-optic medium further comprises a dispersion of electrophoretic particles in a non-polar solvent.

18. The electro-optic display of claim 17 , wherein the electrophoretic particles comprises a plurality of black particles and a plurality of white particles.

19. The electro-optic display of claim 18 , wherein the white particles comprise the photo-luminescent material.

20. The electro-optic display of claim 13 further comprising a light emitting layer, wherein the display is configured such that the photo-luminescent material is excited by light emitted by the light emitting layer.

Assignees

• E Ink Corp

Inventors

• Crounse Kenneth R
• Telfer Stephen J
• Hertel Dirk

Classifications

• G02F1/167 Primary

  by electrophoresis · CPC title

• G02F2202/046

  fluorescent · CPC title

• G02F1/1676

  Electrodes · CPC title

• G02F1/1677 Primary

  Structural association of cells with optical devices, e.g. reflectors or illuminating devices · CPC title

• G02F2001/1678

  characterised by the composition or particle type · CPC title