Light emitting device, method for manufacturing light emitting device, illuminating device, and backlight

Patent metadata

Field	Value
Publication number	US-9287242-B2
Application number	US-201113582951-A
Country	US
Kind code	B2
Filing date	Jan 25, 2011
Priority date	Mar 5, 2010
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

In a light emitting device, one hundred or more bar-like structured light emitting elements ( 210 ) each having a light emitting area of 2,500π μm 2 or less are placed on a mounting surface of one insulating substrate ( 200 ), so that the light emitting device fulfills little variation in luminance, long life, and high efficiency by dispersion of light emission with suppression of increase in temperatures in light emitting operations.

First claim

The invention claimed is:

1. A light emitting device comprising:
a substrate having a mounting surface; and
one hundred or more light emitting elements placed on the mounting surface of the substrate, the light emitting elements each having a light emitting area of 2,500π μm 2 or less,
at least one of the light emitting elements being in shape of a bar,
the at least one light emitting element in shape of a bar having a cylindrical light emitting surface that concentrically surrounds a bar-like core,
no pn junctions, which are perpendicular to an axis direction of the bar, existing in the middle of the bar, and
an area of the mounting surface of the substrate being equal to or larger than four times as large as a sum total of the light emitting areas of the light emitting elements.

2. The light emitting device as claimed in claim 1 , wherein
the bar-like core of the at least one light emitting element is an n-type semiconductor core, and
the at least one light emitting element has a cylindrical p-type semiconductor layer covering an outer peripheral surface of the n-type semiconductor core.

3. The light emitting device as claimed in claim 1 , wherein the light emitting area of each of the light emitting elements is not larger than 625π μm 2 .

4. The light emitting device as claimed in claim 3 , wherein
difference between a center temperature of the light emitting surface and an end part temperature of the light emitting surface is around zero during light emitting operations of the light emitting elements.

5. The light emitting device as claimed in claim 1 , wherein
the light emitting elements are placed on the mounting surface of the substrate while being dispersed uniformly in general.

6. An illuminating device comprising the light emitting device as claimed in claim 1 .

7. A backlight comprising the light emitting device as claimed in claim 1 .

8. A light emitting device comprising:
a substrate having a mounting surface; and
one hundred or more light emitting elements placed on the mounting surface of the substrate, the light emitting elements each having a light emitting area of 2,500π μm 2 or less,
an area of the mounting surface of the substrate being equal to or larger than four times as large as a sum total of the light emitting areas of the light emitting elements.

9. The light emitting device as claimed in claim 8 , wherein the light emitting area of each of the light emitting elements is not larger than 625π μm 2 .

10. The light emitting device as claimed in claim 9 , wherein
difference between a center temperature of the light emitting surface and an end part temperature of the light emitting surface is around zero during light emitting operations of the light emitting elements are emitting light.

11. The light emitting device as claimed in claim 8 , wherein the light emitting elements are dispersed uniformly in general on the mounting surface of the substrate.

12. The light emitting device as claimed in claim 8 , wherein each of the light emitting elements has a flat light emitting surface or a cylindrical light emitting surface.

13. An illuminating device comprising the light emitting device as claimed in claim 8 .

14. A backlight comprising the light emitting device as claimed in claim 8 .

Assignees

• Shibata Akihide
• Negishi Tetsu
• Komiya Kenji
• Iwata Hiroshi
• Takahashi Akira
• Sharp Kk

Inventors

• Shibata Akihide
• Negishi Tetsu
• Komiya Kenji
• Iwata Hiroshi
• Takahashi Akira

Classifications

• H10W72/07554

  changes in dispositions · CPC title

• H10W72/884

  Die-attach connectors and bond wires · CPC title

• H10W72/547

  Dispositions of multiple bond wires · CPC title

• H10W90/00 Primary

  Package configurations · CPC title

• H10H20/821

  of the light-emitting regions, e.g. non-planar junctions · CPC title