Light wavelength conversion member and light emitting device

Patent metadata

Field	Value
Publication number	US-11214731-B2
Application number	US-201716488847-A
Country	US
Kind code	B2
Filing date	Nov 10, 2017
Priority date	Feb 27, 2017
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

An optical wavelength conversion member (9) provided with a ceramic plate (11) which is configured from a polycrystalline body that is mainly composed of Al2O3 and a component represented by A3B5O12:Ce; and each of A and B in A3B5O12 represents at least one element selected from the element groups described below. In addition, a dielectric multilayer film (13) which transmits a specific wavelength and reflects another specific wavelength is formed on a light incident surface (11a) of the ceramic plate (11). The ceramic plate (11) has a porosity of 2% by volume or less, while having an average surface roughness (an arithmetic mean roughness Sa) of 0.5 μm or less. A: Sc, Y and lanthanoids (excluding Ce) B: Al and Ga. Also disclosed is a light-emitting device including the optical wavelength conversion member.

First claim

The invention claimed is:

1. An optical wavelength conversion member comprising a polycrystalline ceramic plate containing, as main components, Al 2 O 3 and a component represented by A 3 B 5 O 12 :Ce, the optical wavelength conversion member being characterized in that:
each of A and B of the A 3 B 5 O 12 is at least one element selected from the following element groups:
A: Sc, Y, and lanthanoids (except for Ce), and
B: Al and Ga; and
the ceramic plate has a porosity of 0.05 vol. % or less and an average surface roughness (arithmetic average roughness Sa) of 0.5 μm or less, and the ceramic plate has, on its surface located on one side in a thickness direction thereof, a dielectric multilayer film including stacked translucent layers having different refractive indices.

2. An optical wavelength conversion member according to claim 1 , wherein the ceramic plate has open pores at the interface between the dielectric multilayer film and the ceramic plate in a cross section of the optical wavelength conversion member in the thickness direction; the number of open pores is 30 or less per 100 μm of the length of the interface; and each open pore has an opening size of 2 μm or less.

3. An optical wavelength conversion member according to claim 1 , wherein the ceramic plate has an A 3 B 5 O 12 :Ce content of 5 to 50 vol. %.

4. An optical wavelength conversion member according to claim 1 , wherein the Ce content of the A 3 B 5 O 12 :Ce is 10.0 mol % or less (exclusive of 0) relative to the element A.

5. An optical wavelength conversion member according to claim 1 , wherein the ceramic plate has, on its surface located on the other side in the thickness direction thereof, a translucent antireflection layer for preventing light reflection.

6. A light-emitting device comprising an optical wavelength conversion member as recited in claim 1 , the light-emitting device being characterized in that:
light is incident on the surface of the optical wavelength conversion member on which the dielectric multilayer film is provided.

7. An optical wavelength conversion member according to claim 1 , wherein the dielectric multilayer film comprises a plurality of high refractive index films and a plurality of low refractive index films alternately disposed one by one, wherein the high refractive index films have a refractive index that is higher those of the low refractive index films.

8. An optical wavelength conversion member according to claim 1 , wherein the dielectric multilayer film transmits or reflects light of a specific wavelength.

9. An optical wavelength conversion member according to claim 1 , wherein the dielectric multilayer film comprises a dichroic coating.

10. An optical wavelength conversion member according to claim 7 , wherein the dielectric multilayer film comprises alternately stacked high refractive index titanium oxide films and low refractive index silicon oxide films.

Assignees

• Ngk Spark Plug Co

Inventors

• Ito Tsuneyuki
• Katsu Yusuke
• TAKAKU Shohei

Classifications

• C09K11/7774 Primary

  Aluminates · CPC title

• C09K11/02 Primary

  Use of particular materials as binders, particle coatings or suspension media therefor · CPC title

• H10H20/851

  Wavelength conversion means · CPC title

• G02B5/28 Primary

  Interference filters · CPC title

• H10H20/8512

  Wavelength conversion materials · CPC title