Fluorescent member, optical component, and light emitting device

Patent metadata

Field	Value
Publication number	US-10442987-B2
Application number	US-201816118209-A
Country	US
Kind code	B2
Filing date	Aug 30, 2018
Priority date	Aug 31, 2017
Publication date	Oct 15, 2019
Grant date	Oct 15, 2019

Abstract

A fluorescent member includes: a plurality of fluorescent particles; an inorganic binder; and a plurality of pores. An upper surface of the fluorescent member is a light extraction surface of the fluorescent member. The plurality of pores are localized in a vicinity of at least one of the plurality of fluorescent particles in a cross section that is parallel to the upper surface of the fluorescent member and extends through the fluorescent particles and the pores.

First claim

What is claimed is:

1. A fluorescent member comprising:
a plurality of fluorescent particles;
an inorganic binder; and
a plurality of pores;
wherein an upper surface of the fluorescent member is a light extraction surface of the fluorescent member, and
wherein the plurality of pores are localized in a vicinity of at least one of the plurality of fluorescent particles in a cross section that is parallel to the upper surface of the fluorescent member and extends through the fluorescent particles and the pores.

2. The fluorescent member according to claim 1 , wherein some of the plurality of pores are provided along a periphery of said at least one of the fluorescent particles in the cross section.

3. The fluorescent member according to claim 1 , wherein an area of each of the plurality of pores is smaller than an area of each of the plurality of fluorescent particles in the cross section.

4. The fluorescent member according to claim 1 , wherein:
a refractive index of each of the plurality of pores is lower than a refractive index of the inorganic binder,
the refractive index of the inorganic binder is lower than the refractive index of each of the plurality of fluorescent particles, and
some of the plurality of pores are in direct contact with the fluorescent particles.

5. The fluorescent member according to claim 1 , wherein:
a content of the fluorescent particles in the fluorescent member is greater than or equal to 40% by mass and less than or equal to 70% by mass, and
an incident surface of the fluorescent member, on which excitation light for exciting the fluorescent particles is incident, coincides with the upper surface of the fluorescent member.

6. The fluorescent member according to claim 1 ,
wherein the particle size of the fluorescent particle is greater than or equal to 1 μm and less than or equal to 20 μm.

7. The fluorescent member according to claim 1 ,
wherein a sintered density of the fluorescent member is greater than or equal to 90% and less than or equal to 98%.

8. The fluorescent member according to claim 1 ,
wherein an area of each of the plurality of pores is greater than or equal to 0.01 μm 2 and less than or equal to 2 μm 2 .

9. The fluorescent member according to claim 1 ,
wherein the plurality of pores are provided on ⅓ or more of an entire periphery of said at least one of the fluorescent particles.

10. An optical component comprising:
the fluorescent member according to claim 1 , the fluorescent member having a lower surface opposite to the upper surface; and
a base connected to the lower surface of the fluorescent member, a thermal conductivity of the base being higher than a thermal conductivity of the fluorescent member.

11. The optical component according to claim 10 , wherein the base comprises at least one of a metal or a light-diffusing ceramic.

12. The optical component according to claim 10 , further comprising a reflective film located on the lower surface of the fluorescent member.

13. The optical component according to claim 12 , further comprising a diffusion preventive layer located on the lower surface of the reflective film.

14. The optical component according to claim 10 , wherein:
an upper surface of the base has a light-reflecting property, and
the upper surface of the base and the lower surface of the fluorescent member are connected by a transparent bonding member.

15. The optical component according to claim 14 , further comprising a reflective film located on the upper surface of the base.

16. The optical component according to claim 14 , wherein the lower surface of the fluorescent member has at least one concave portion filled with the transparent bonding member.

17. The optical component according to claim 14 , wherein:
a part of the upper surface of the base has a convex portion, and
the fluorescent member is connected to the convex portion.

18. The optical component according to claim 17 , further comprising a reflective film and a transparent bonding member located on the convex portion, in this order from the base.

19. A light emitting device comprising:
the optical component according to claim 10 ; and
a semiconductor laser element configured to irradiate an excitation light in a visible region on the fluorescent member, the semiconductor laser element disposed such that the excitation light from the semiconductor laser element is obliquely incident on the upper surface of the fluorescent member.

20. The light emitting device according to claim 19 , further comprising a mirror configured to reflect the excitation light from the semiconductor laser element toward the upper surface of the fluorescent member.

Assignees

• Nichia Corp

Inventors

• Takasone Toru
• Sano Masahiko
• Inoue Hiroyuki
• Yamada Shoichi
• Sugiyama Takafumi

Classifications

• F21V9/30

  Elements containing photoluminescent material distinct from or spaced from the light source (shades F21V1/17; globes, bowls or cover glasses F21V3/08, F21V3/12; refractors F21V5/10; reflectors F21V7/26, F21V7/30; elements with provision for controlling the spectral properties or intensity F21V9/40) · CPC title

• C04B2235/3222

  Aluminates other than alumino-silicates, e.g. spinel (MgAl2O4) · CPC title

• F21K2/06 Primary

  using chemiluminescence · CPC title

• F21V7/30

  the coatings comprising photoluminescent substances · CPC title

• C04B38/0054

  the pores being microsized or nanosized · CPC title