Displays with direct-lit backlight units

Patent metadata

Field	Value
Publication number	US-12372828-B2
Application number	US-202418643945-A
Country	US
Kind code	B2
Filing date	Apr 23, 2024
Priority date	Apr 16, 2021
Publication date	Jul 29, 2025
Grant date	Jul 29, 2025

Abstract

A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated with backlight illumination from a direct-lit backlight unit. The backlight unit may include an array of light-emitting diodes on a printed circuit board. The backlight unit may include first, second, and third light spreading layers formed over the array of light-emitting diodes. A color conversion layer may be formed over the first, second, and third light spreading layers. First and second brightness enhancement films may be formed over the color conversion layer.

First claim

What is claimed is:

1. A display, comprising:
a plurality of pixels; and
a backlight configured to produce backlight illumination for the plurality of pixels, wherein the backlight comprises:
a substrate;
a plurality of light sources mounted on the substrate; and
a color conversion layer that receives light from the plurality of light sources, wherein the color conversion layer comprises:
a phosphor layer;
a partially reflective layer; and
an anti-static layer, wherein the phosphor layer is interposed between the anti-static layer and the partially reflective layer.

2. The display defined in claim 1 , wherein the color conversion layer further comprises:
a plurality of protrusions, wherein the anti-static layer is interposed between the plurality of protrusions and the phosphor layer.

3. The display defined in claim 2 , wherein the plurality of protrusions is a plurality of pyramidal protrusions.

4. The display defined in claim 2 , wherein the color conversion layer further comprises:
a base film that is interposed between the phosphor layer and the plurality of protrusions.

5. The display defined in claim 4 , wherein the anti-static layer is interposed between the base film and the plurality of protrusions.

6. The display defined in claim 4 , wherein a static decay time at a bottom surface of the base film is less than 10 seconds.

7. The display defined in claim 1 , wherein the color conversion layer further comprises:
a low-index layer that is interposed between the anti-static layer and the partially reflective layer.

8. The display defined in claim 7 , wherein the low-index layer has an index of refraction that is less than 1.4.

9. A display, comprising:
a plurality of pixels; and
a backlight configured to produce backlight illumination for the plurality of pixels, wherein the backlight comprises:
a printed circuit board;
a plurality of light-emitting diodes mounted on the printed circuit board;
an optical film formed over the printed circuit board that receives light from the plurality of light-emitting diodes; and
an ink that is patterned on the optical film, wherein the ink comprises clear ink or yellow ink.

10. The display defined in claim 9 , wherein the ink is interposed between the optical film and the printed circuit board.

11. The display defined in claim 10 , wherein the optical film has first and second opposing surfaces, wherein the ink is patterned on the second surface of the optical film, and wherein a plurality of protrusions extends across the first surface of the optical film.

12. The display defined in claim 9 , wherein the ink is applied uniformly across a surface of the optical film.

13. The display defined in claim 9 , wherein the ink comprises yellow ink and wherein the yellow ink is configured to compensate for a blue tint in a border of the display.

14. The display defined in claim 13 , wherein a density of the ink decreases with increasing distance from an edge of the optical film.

15. The display defined in claim 14 , further comprising:
an additional ink that is patterned on the optical film, wherein the additional ink comprises clear ink, and wherein an additional density of the additional ink increases with increasing distance from the edge of the optical film.

16. The display defined in claim 9 , wherein the ink is configured to decrease a coefficient of friction of the optical film.

17. A display, comprising:
a printed circuit board;
an array of light sources mounted on the printed circuit board in a first area; and
a plurality of electronic components mounted on the printed circuit board in a second area, wherein the plurality of electronic components includes a first electronic component having first and second opposing sides connected by third and fourth opposing sides and wherein the first electronic component is surrounded by encapsulant on the first, second, and third sides but not the fourth side.

18. The display defined in claim 17 , wherein the plurality of electronic components includes:
a second electronic component, wherein the fourth side of the first electronic component is adjacent to the second electronic component; and
a third electronic component that is surrounded by additional encapsulant on three sides and is not surrounded by the additional encapsulant on a side adjacent to the second electronic component.

19. The display defined in claim 18 , wherein the first electronic component comprises an electronic component selected from the group consisting of: a capacitor, a resistor, and an inductor.

20. The display defined in claim 19 , wherein the second electronic component comprises a driver integrated circuit configured to provide a signal to at least one of the light sources.

Assignees

• Apple Inc

Inventors

• Xu Daming
• Yan Yufeng
• Wang Qingbing
• You Chenhua
• Liu Rong
• Qi Jun
• Luo Zhenyue
• Son Mookyung
• Yin Victor H

Classifications

• 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

• G02F1/133614

  using photoluminescence, e.g. phosphors illuminated by UV or blue light · CPC title

• G02F1/133608

  including particular frames or supporting means · CPC title

• G02F1/133612

  Electrical details · CPC title