Reflective color pixel

• US 8,998,434 B2
• Filed: 09/30/2010
• Issued: 04/07/2015
• Est. Priority Date: 09/30/2010
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Gibson, Gary
• Primary Examiner(s): BRUCE, DAVID VERNON
• Application Number:
  US13/876,374
• Publication Number:
  US 20130182410A1
• Time in Patent Office: 1,650 Days
• Field of Search: 362/87, 362/97.2
• US Class Current: 362/84
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133521 Interference filters
• CPC Class Codes: G02F 1/133553 Reflecting elements associated to illuminating devices G02F1/133605
• CPC Class Codes: G02F 1/133614 using photoluminescence, e.g. phosphors illuminated by UV or blue light
• CPC Class Codes: G02F 1/133618 for ambient light
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence

Abstract

A reflective color pixel includes a first sub-pixel and a second sub-pixel. The first sub-pixel is for generating a first color. A color conversion layer extends through the first sub-pixel and the second sub-pixel and is disposed in a waveguide. The color conversion layer contains a luminescent material, which converts a portion of light incident on the second sub-pixel into light of the first color. The waveguide guides the light of the first color generated by the luminescent material to the first sub-pixel for emission from the first sub-pixel.

Claims

1. A reflective color pixel comprising:

a first sub-pixel and a second sub-pixel, the first sub-pixel for generating a first color; and

a color conversion layer extending through the first sub-pixel and the second sub-pixel, the color conversion layer being disposed in a waveguide and containing a luminescent material, the luminescent material converting a portion of light incident on the second sub-pixel into light of the first color, and the waveguide guiding the light of the first color generated by the luminescent material to the first sub-pixel for emission from the first sub-pixel.

2. A reflective display pixel as in claim 1, wherein the first color is selected from the group of red, green and blue.

3. A reflective color pixel as in claim 1, wherein the second sub-pixel is for emitting light of a second color.

4. A reflective color pixel as in claim 3, wherein the second color is blue and the first color is red or green.

5. A reflective color pixel as in claim 1, wherein the luminescent material includes luminophores comprising relay dyes for generating light of the first color.

6. A reflective color pixel as in claim 1, wherein each of the first and second sub-pixels has an upper mirror disposed on a first side of the color conversion layer, and the pixel has a bottom mirror disposed on a second side of the color conversion layer, the upper mirrors of the sub-pixels and the bottom mirror forming the waveguide for the color conversion layer.

7. A reflective color pixel as in claim 6, wherein each of the first and second sub-pixels further includes a shutter and an absorber, the shutter controlling light transmission through the sub-pixel and the absorber absorbing a portion of light reflected by the upper mirror of the sub-pixel.

8. A reflective color pixel comprising:

a first sub-pixel for emitting a first color;

a second sub-pixel for emitting a second color;

a third sub-pixel for emitting a third color;

a color conversion layer extending through the first, second and third sub-pixels, the color conversion layer containing a luminescent material for generating light of the first color and light of the second color;

a waveguide in which the color conversion layer is disposed, the waveguide guiding light generated by the luminescent material in one sub-pixel to the other sub-pixels.

9. A reflective color pixel as in claim 8, wherein each of the first, second and third sub-pixels includes an upper mirror disposed on a first side of the color conversion layer, and the pixel has a bottom mirror disposed on second side of the color conversion layer, the upper mirrors of the sub-pixels and the bottom minor forming the waveguide.

10. A reflective color pixel as in claim 9, wherein the color conversion layer within the first sub-pixel contains luminophores for generating light of the third color, the color conversion layer within the second sub-pixel contains luminophores for generating light of the second color, and the conversion layer within the third sub-pixel contains luminophores for generating light of the third color.

11. A reflective color pixel as in claim 8, further including a fourth sub-pixel for collecting light, wherein the color conversion layer extends through the fourth sub-pixel.

12. A reflective color pixel as in claim 11, wherein the luminescent material contains luminophores for the generating light of the first, second, and third colors.

13. A reflective color display comprising:

a plurality of pixels, each pixel having a first sub-pixel for emitting a first color, a second sub-pixel for emitting a second color, and a third sub-pixel for emitting a third color, a color conversion layer extending through the sub-pixels and containing a luminescent material for generating light of the first and second color, a waveguide containing the color conversion layer configured to guide a portion of light generated by the luminescent material within one sub-pixel to the other sub-pixels.

14. A reflective color display as in claim 13, wherein the color conversion layer extends through multiple pixels.

15. A reflective color display as in claim 13, where the pixel further includes a fourth sub-pixel for light collection, and the luminescent material also generates light of the third color.