Quantum dot-enhanced display having dichroic filter

Patent metadata

Field	Value
Publication number	US-9810942-B2
Application number	US-201514944016-A
Country	US
Kind code	B2
Filing date	Nov 17, 2015
Priority date	Jun 15, 2012
Publication date	Nov 7, 2017
Grant date	Nov 7, 2017

Abstract

A display device is provided. The display device includes a light source emitting a blue light and a light emitting layer including a first group of red quantum dots and a second group of green quantum dots. The light emitting layer is configured to absorb a first portion of the blue light from the light source to emit red light and green light and to transmit a second portion of the blue light. The display device also includes dichroic filter layers to improve light recycling and backlight efficiency.

First claim

What is claimed is:

1. A display, comprising:
a display module; and
backlight structures that provide light to the display module, wherein the backlight structures include:
blue light-emitting diodes that provide blue light;
a light-conversion film that converts the blue light into light of at least one different color;
a first dichroic filter;
a second dichroic filter, wherein the light-conversion film is interposed between the first and second dichroic filters; and
a prism layer interposed between the second dichroic filter and the display module, wherein the prism layer reflects on-axis light and collimates off-axis light.

2. The display defined in claim 1 wherein the light-conversion film comprises a phosphor film.

3. The display defined in claim 1 wherein the light-conversion film comprises a quantum dot film.

4. The display defined in claim 1 wherein the first dichroic filter and the second dichroic filter have different transmission spectrums.

5. The display defined in claim 1 further comprising a reflective polarizer laminated to the second dichroic filter.

6. The display defined in claim 1 wherein the light of the different color includes red light and green light and wherein the light of the different color is reflected by the first dichroic filter.

7. The display defined in claim 1 wherein the light of the different color includes yellow light that is reflected by the first dichroic filter.

8. The display defined in claim 1 wherein the first dichroic filter is interposed between the light-conversion film and the light-emitting diodes.

9. The display defined in claim 1 wherein the second dichroic filter is interposed between the display module and the light-conversion film.

10. The display defined in claim 1 wherein the display module comprises a liquid crystal display module.

11. The display defined in claim 1 wherein the blue light-emitting diodes are arranged in an array and directly light the light-conversion film.

12. The display defined in claim 1 further comprising a reflective polarizer, wherein the prism layer is interposed between the second dichroic filter and the reflective polarizer.

13. The display defined in claim 1 wherein the first dichroic filter passes blue light and reflects the light of the different color.

14. The display defined in claim 13 wherein the second dichroic filter reflects more blue light than passes blue light and wherein the second dichroic filter passes the light of the different color.

15. The display defined in claim 1 wherein the light-conversion film comprises a quantum dot film with red and green quantum dots and wherein the light of the different color comprises red and green light from the red and green quantum dots.

16. The display defined in claim 15 wherein the first dichroic filter reflects at least 95% of the red and green light and passes at least 90% of the blue light.

17. The display defined in claim 16 wherein the second dichroic filter reflects at least 55% of blue light exiting the quantum dot film and passes at least 95% of the red and green light from the quantum dot film.

18. A display, comprising:
a liquid crystal display module;
backlight structures that provide backlight for the liquid crystal display module, wherein the backlight structures comprise:
a blue light-emitting diode that produces blue light;
a quantum dot film that receives the blue light and that produces light of a different color;
a first dichroic filter;
a second dichroic filter, wherein the quantum dot film is interposed between the first and second dichroic filters; and
a prism layer interposed between the second dichroic filter and the liquid crystal display module, wherein the prism layer reflects on-axis light and collimates off-axis light.

Assignees

• Apple Inc

Inventors

• You Chenhua
• Qi Jun
• Hsu Fan-Chung
• Yin Victor H

Classifications

• G02F1/133609

  including means for improving the color mixing, e.g. white · CPC title

• G02F2202/108

  quantum wells · CPC title

• G02F2001/133614

  Physics · mapped topic

• G02F1/133615

  Edge-illuminating devices, i.e. illuminating from the side · CPC title

• G02F1/133603 Primary

  with LEDs · CPC title