Light-emitting unit and surface-emission light source

Patent metadata

Field	Value
Publication number	US-11799064-B2
Application number	US-202217842925-A
Country	US
Kind code	B2
Filing date	Jun 17, 2022
Priority date	Aug 2, 2019
Publication date	Oct 24, 2023
Grant date	Oct 24, 2023

Abstract

A light-emitting unit includes: a wiring board; a plurality of light-emitting elements provided on the wiring board and electrically coupled with a wire layer of the wiring board; a light reflecting member provided on the wiring board, the light reflecting member covering a lateral surface of each of the plurality of light-emitting elements; a light diffusing layer covering the plurality of light-emitting elements and the light reflecting member; a wavelength conversion layer located on or above the light diffusing layer; and a plurality of light reflecting layers located between the light diffusing layer and the wavelength conversion layer, each of the light reflecting layers being located above a corresponding one of the plurality of light-emitting elements. An upper surface of the light reflecting member has a recess which includes at least one concave surface, and there is a space between the concave surface and the light diffusing layer.

First claim

The invention claimed is:

1. A light-emitting unit comprising:
a wiring board;
a plurality of light-emitting elements provided on the wiring board and electrically coupled with a wire layer of the wiring board;
a light reflecting member provided on the wiring board, the light reflecting member at least including a portion located between two adjacent light-emitting elements;
a light diffusing layer covering the plurality of light-emitting elements and the light reflecting member;
a wavelength conversion layer located on or above the light diffusing layer; and
a plurality of light reflecting layers located between the light diffusing layer and the wavelength conversion layer, each of the light reflecting layers being located above a corresponding one of the plurality of light-emitting elements,
wherein a vertical space exists between the wavelength conversion layer and a region of an upper surface of the light diffusing layer exclusive of regions overlapping the light reflecting layers in a plan view.

2. The light-emitting unit of claim 1 , wherein
each of the plurality of light reflecting layers has a dotted reflection pattern in a top view, and
in each of the plurality of light reflecting layers, a dot density of the reflection pattern increases from a periphery to a center of the light reflecting layer.

3. The light-emitting unit of claim 1 , wherein an upper surface of the light reflecting member has a recess which includes at least one concave surface.

4. The light-emitting unit of claim 3 , wherein a distance between the concave surface and the light diffusing layer increases as a distance from the light-emitting elements increases when viewed in plan.

5. The light-emitting unit of claim 1 , wherein a region of each of the light reflecting layers has a circular or rectangular shape when viewed in plan and includes an emission surface of a corresponding one of the plurality of light-emitting elements.

6. The light-emitting unit of claim 1 , wherein the wiring board is a flexible printed circuit.

7. The light-emitting unit of claim 1 , wherein
the wavelength conversion layer includes a plurality of first regions and a second region surrounding the plurality of first regions, each of the first regions and the second region containing a phosphor,
a density of the phosphor in the first regions is higher than a density of the phosphor in the second region, and
each of the first regions is located above a corresponding one of the plurality of light-emitting elements.

8. The light-emitting unit of claim 7 , wherein a thickness of the wavelength conversion layer is greater in the first regions than in the second region.

9. The light-emitting unit of claim 1 , wherein
the wavelength conversion layer includes a plurality of first regions and a second region surrounding the plurality of first regions, each of the first regions and the second region containing a phosphor,
a thickness of the wavelength conversion layer is greater in the first regions than in the second region, and
each of the first regions is located above a corresponding one of the plurality of light-emitting elements.

10. The light-emitting unit of claim 9 , wherein
the wavelength conversion layer includes a second wavelength conversion layer provided on each of the first regions, and
a density of the phosphor in the second wavelength conversion layer is higher than a density of the phosphor in a remaining part of the wavelength conversion layer.

11. A surface-emission light source comprising:
the light-emitting unit as set forth in claim 1 ;
a diffuser provided on or above the wavelength conversion layer; and
a prism sheet provided on or above the diffuser.

12. A light-emitting unit comprising:
a wiring board;
a plurality of light-emitting elements provided on the wiring board and electrically coupled with a wire layer of the wiring board;
a light reflecting member provided on the wiring board, the light reflecting member at least including a portion located between two adjacent light-emitting elements;
a light diffusing layer covering the plurality of light-emitting elements and the light reflecting member;
a wavelength conversion layer located on or above the light diffusing layer; and
a plurality of light reflecting layers each being located above a corresponding one of the plurality of light-emitting elements,
wherein the light diffusing layer is a multi-layer structure that includes a first light diffusing layer, a second light diffusing layer and a third light diffusing layer which are arranged in this order from the wiring board toward the wavelength conversion layer,
wherein the plurality of light reflecting layers are located between the first light diffusing layer and the second light diffusing layer, and
wherein a vertical space exists between the second light diffusing layer and a region of an upper surface of the first light diffusing layer exclusive of regions overlapping the light reflecting layers in a plan view.

13. The light-emitting unit of claim 12 , wherein
each of the plurality of light reflecting layers has a dotted reflection pattern in a top view, and
in each of the plurality of light reflecting layers, a dot density of the reflection pattern increases from a periphery to a center of the light reflecting layer.

14. The light-emitting unit of claim 12 , wherein an upper surface of the light reflecting member has a recess which includes at least one concave surface.

15. The light-emitting unit of claim 14 , wherein a distance between the concave surface and the light diffusing layer increases as a distance from the light-emitting elements increases when viewed in plan.

16. The light-emitting unit of claim 12 , wherein a region of each of the light reflecting layers has a circular or rectangular shape when viewed in plan and includes an emission surface of a corresponding one of the plurality of light-emitting elements.

17. The light-emitting unit of claim 12 , wherein the wiring board is a flexible printed circuit.

18. The light-emitting unit of claim 12 , wherein the plurality of light reflecting layers are provided on an upper surface of the first light diffusing layer.

19. The light-emitting unit of claim 12 , wherein
the wavelength conversion layer includes a plurality of first regions and a second region surrounding the plurality of first regions, each of the first regions and the second region containing a phosphor,
a density of the phosphor in the first regions is higher than a density of the phosphor in the second region, and
each of the first regions is located above a corresponding one of the plurality of light-emitting elements.

20. The light-emitting unit of claim 19 , wherein a thickness of the wavelength conversion layer is greater in the first regions than in the second region.

21. The light-emitting unit of claim 12 , wherein
the wavelength conversion layer includes a plurality of first regions and a second region surrounding the plurality of first regions, each of the first regions and the second region containing a phosphor,
a thickness of the wavelength conversion layer is greater in the first regions than in the second region, and
each of the first regions is located above a corresponding one of the plurality of light-emitting elements.

22. The light-emitting unit of claim 21 , wherein
the wavelength conversion layer includes a second wavelength conversion layer provided on each of the first regions, and
a density

Assignees

• Nichia Corp

Inventors

• Nakabayashi Takuya
• Katsumata Toshinobu
• Hiraide Noriaki

Classifications

• H10W90/00 Primary

  Package configurations · CPC title

• H10H29/142

  Two-dimensional arrangements, e.g. asymmetric LED layout · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title

• H10H20/8506

  Containers · CPC title

• H10H20/856

  Reflecting means · CPC title