Nanostructure based display devices

Patent metadata

Field	Value
Publication number	US-2019064591-A1
Application number	US-201816108319-A
Country	US
Kind code	A1
Filing date	Aug 22, 2018
Priority date	Aug 25, 2017
Publication date	Feb 28, 2019
Grant date	—

Abstract

Embodiments of a display device are described. A display device includes a backlight unit having a light source and a liquid crystal display (LCD) module. The LCD module includes a phosphor film and a filter element. The phosphor film is configured to receive a primary light, from the light source, having a first peak wavelength and to convert a portion of the primary light to emit a secondary light having a second peak wavelength. The second peak wavelength is different from the first peak wavelength. The filter element is optically coupled to the phosphor film and is configured to allow the secondary light to pass through the filter element and to block an unconverted portion of the primary light from passing through the filter element.

First claim

What is claimed is:

1 . A display device comprising:
a backlight unit comprising a light source; and a liquid crystal display (LCD) module comprising:
a phosphor film configured to receive a primary light, from the light source, having a first peak wavelength and to convert a portion of the primary light to emit a secondary light having a second peak wavelength that is different from the first peak wavelength; and
a filter element, optically coupled to the phosphor film, configured to allow the secondary light to pass through the filter element and to block an unconverted portion of the primary light from passing through the filter element.

2 . The display device of claim 1 , wherein the filter element is configured to absorb the unconverted portion of the primary light.

3 . The display device of claim 1 , wherein the filter element is configured to scatter the unconverted portion of the primary light.

4 . The display device of claim 1 , wherein the filter element is disposed on the phosphor film.

5 . The display device of claim 1 , wherein the filter element is disposed on a substrate that is disposed on the phosphor film.

6 . The display device of claim 1 , wherein:
the phosphor film comprises a matrix; and the filter element is embedded in the matrix.

7 . The display device of claim 1 , wherein the filter element comprises a non-phosphor based material.

8 . The display device of claim 1 , wherein the filter element comprises a dye, ink, paint, or polymeric material.

9 . The display device of claim 1 , wherein the filter element comprises a scattering material.

10 . The display device of claim 1 , wherein the filter element comprises scattering particles having titanium oxide, zinc oxide, zinc sulfide, silicone, or a combination thereof.

11 . The display device of claim 1 , wherein the phosphor film comprises luminescent nanostructures.

12 . The display device of claim 1 , wherein the phosphor film comprises an array of segmented phosphor films.

13 . The display device of claim 1 , wherein:
the phosphor film comprises an array of phosphor films; at least one of the phosphor films of the array comprises a first population of luminescent nanostructures configured to emit red light; and at least one of the phosphor films of the array comprises a second population of luminescent nanostructures configured to emit green light.

14 . The display device of claim 1 , wherein the phosphor film comprises:
a first region having a first population of luminescent nanostructures configured to emit red light; and a second region having a second population of luminescent nanostructures configured to emit green light.

15 . The display device of claim 1 , wherein:
the phosphor film comprises an array of phosphor films; at least one of the phosphor films of the array comprises a first population of luminescent nanostructures configured to emit red light; and at least one of the phosphor films of the array comprises a second population of luminescent nanostructures configured to emit green light; and at least one of the phosphor films of the array comprises a third population of luminescent nanostructures configured to emit blue light.

16 . The display device of claim 1 , wherein the phosphor film comprises:
a first region having a first population of luminescent nanostructures configured to emit red light; a second region having a second population of luminescent nanostructures configured to emit green light; and a third region having a third population of luminescent nanostructures configured to emit blue light.

17 . The display device of claim 1 , wherein the LCD module further comprises:
a first polarizing filter configured to polarize the primary light; a liquid crystal solution layer configured to adjust an angle of polarization of the polarized primary light; and a second polarizing filter, disposed between the phosphor film and the liquid crystal solution layer, configured to control transmission of the polarized primary light from the liquid crystal solution layer to the phosphor film.

18 . The display device of claim 1 , wherein the filter element is further configured to tune a spectral emission width of the secondary light to adjust color gamut coverage of a standard RGB color space.

19 . The display device of claim 1 , wherein the filter element is further configured to tune a spectral emission width of the secondary light to achieve over 90% color gamut coverage of a standard RGB color space.

20 . The display device of claim 19 , wherein the standard RGB color space is Rec. 2020 color space.

21 . The display device of claim 1 , wherein the filter element is further configured to tune the spectral emission width of the secondary light to achieve over 90% color gamut coverage of Rec. 2020 color space with less than 10% decrease in brightness level of the display device.

22 . The display device of claim 1 , further comprising an optical cavity, wherein the light source is positioned within the optical cavity.

23 . The display device of claim 1 , further comprising a light guide plate, wherein the light source is externally coupled to the light guide plate.

24 . A display device comprising:
an organic light emitting diode (OLED); and a phosphor film configured to receive a primary light, from the OLED, having a first peak wavelength and to convert a portion of the primary light to emit a secondary light having a second peak wavelength that is different from the first peak wavelength; and a filter element, optically coupled to the phosphor film, configured to allow the secondary light to pass through the filter element and to block an unconverted portion of the primary light from passing through the filter element.

25 . The display device of claim 24 , wherein the OLED, the phosphor film, and the filter element are parts of a pixel of the display device.

26 . The display device of claim 24 , wherein the filter element is configured to absorb the unconverted portion of the primary light.

27 . The display device of claim 24 , wherein the filter element is configured to scatter the unconverted portion of the primary light.

28 . The display device of claim 24 , wherein the filter element is disposed on the phosphor film.

29 . The display device of claim 24 , wherein the filter element is disposed on a substrate that is disposed on the phosphor film.

30 . The display device of claim 24 , wherein:
the phosphor film comprises a matrix; and the filter element is embedded in the matrix.

31 . The display device of claim 24 , wherein the filter element comprises a non-phosphor based material.

32 . The display device of claim 24 , wherein the filter element comprises a dye, ink, paint, or polymeric material.

33 . The display device of claim 24 , wherein the filter element comprises a scattering material.

34 . The display device of claim 24 , wherein the filter element comprises scattering particles having titanium oxide, zinc oxide, zinc sulfide, silicone, or a combination thereof.

35 . The display device of claim 24 , wherein the phosphor film comprises luminescent nanostructures.

36 . The display device o

Assignees

• Nanosys Inc

Inventors

• Lee Ernest
• Hartlove Jason
• Kan Shihai
• Chen Jian

Classifications

• G02F1/133617

  Illumination with ultraviolet light; Luminescent elements or materials associated to the cell · CPC title

• G02F1/133611

  including means for improving the brightness uniformity · CPC title

• G02F1/133606

  including a specially adapted diffusing, scattering or light controlling members · CPC title

• G02F1/133603 Primary

  with LEDs · CPC title

• G02F2001/1351

  Physics · mapped topic