Wavelength conversion member including phosphor

Patent metadata

Field	Value
Publication number	US-10365551-B2
Application number	US-201715468179-A
Country	US
Kind code	B2
Filing date	Mar 24, 2017
Priority date	Apr 22, 2016
Publication date	Jul 30, 2019
Grant date	Jul 30, 2019

Abstract

A wavelength conversion member comprises: a substrate; and a wavelength conversion layer. The wavelength conversion layer contains a first phosphor and a second phosphor. The second phosphor has a higher thermal conductivity than the first phosphor. In the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor. The wavelength conversion layer includes a first portion and a second portion. The first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion. Thicknesses of the first portion and the second portion are equal to each other. A volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22.

First claim

What is claimed is:

1. A wavelength conversion member comprising:
a substrate; and
a wavelength conversion layer that has a first surface in direct contact with the substrate, and a second surface opposite to the first surface,
wherein the wavelength conversion layer contains a first phosphor that emits first light having longer wavelengths than excitation light, and a second phosphor that emits second light having longer wavelengths than the excitation light,
the second phosphor has a higher thermal conductivity than the first phosphor,
in the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor,
the wavelength conversion layer includes a first portion having the first surface and a second portion having the second surface,
the first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion,
thicknesses of the first portion and the second portion are equal to each other, and
a volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22,
wherein the second surface of the wavelength conversion layer is a surface on which excitation light from a semiconductor light-emitting element is incident.

2. The wavelength conversion member according to claim 1 , wherein V11/V12 is 0.

3. The wavelength conversion member according to claim 1 , wherein the second surface is a surface from which at least one selected from the group consisting of the first light and the second light is emitted.

4. The wavelength conversion member according to claim 1 , wherein a peak wavelength of the first light is shorter than a peak wavelength of the second light.

5. The wavelength conversion member according to claim 1 , wherein the first phosphor is a phosphor expressed by (Sr 1-x Ba x ) 5 P 3 O 12 Cl:Eu 2+ [0≤x≤1].

6. The wavelength conversion member according to claim 1 , wherein the first phosphor is a phosphor expressed by (Sr 1-x Ba x ) 3 MgSi 2 O 8 :Eu 2+ [0≤x≤1].

7. The wavelength conversion member according to claim 1 , wherein the second phosphor is a phosphor expressed by
(Y 1-y Gd y ) 3 (Al 1-z Ga z ) 5 O 12 :Ce 3+ [0 ≤y <1,0 ≤z <1].

8. The wavelength conversion member according to claim 1 , wherein the second phosphor is a phosphor expressed by Lu 3 Al 5 O 12 :Ce 3+ .

9. The wavelength conversion member according to claim 1 , wherein the second portion contains at least part of the first phosphor and at least part of the second phosphor.

10. A projector comprising a semiconductor light-emitting element that emits excitation light having a peak wavelength of not shorter than 380 nm and not longer than 420 nm; and
a wavelength conversion member on which the excitation light is incident,
the wavelength conversion member comprising a substrate, and a wavelength conversion layer that has a first surface in direct contact with the substrate, and a second surface opposite to the first surface,
wherein the wavelength conversion layer contains a first phosphor that emits first light having longer wavelengths than the excitation light, and a second phosphor that emits second light having longer wavelengths than the excitation light,
the second phosphor has a higher thermal conductivity than the first phosphor,
in the wavelength conversion layer, a volume of the second phosphor is larger than a volume of the first phosphor,
the wavelength conversion layer includes a first portion having the first surface and a second portion having the second surface,
the first portion is located closer to the substrate than the second portion, and is in direct contact with the second portion,
thicknesses of the first portion and the second portion are equal to each other, and
a volume V11 of the first phosphor in the first portion, a volume V12 of the second phosphor in the first portion, a volume V21 of the first phosphor in the second portion, and a volume V22 of the second phosphor in the second portion satisfy V11/V12<V21/V22,
wherein the second surface of the wavelength conversion layer is a surface on which the excitation light from the semiconductor light-emitting element is incident.

11. The projector according to claim 10 , wherein V11/V12 is 0.

12. The projector according to claim 10 , wherein the second surface is a surface from which at least one selected from the group consisting of the first light and the second light is emitted.

13. The projector according to claim 10 , wherein a peak wavelength of emission light from the first phosphor is shorter than a peak wavelength of emission light from the second phosphor.

14. The projector according to claim 10 , wherein the first phosphor is a phosphor expressed by (Sr 1-x Ba x ) 5 P 3 O 12 Cl:Eu 2+ [0≤x≤1].

15. The projector according to claim 10 , wherein the first phosphor is a phosphor expressed by (Sr 1-x Ba x ) 3 MgSi 2 O 8 :Eu 2+ [0≤x≤1].

16. The projector according to claim 10 , wherein the second phosphor is a phosphor expressed by (Y 1-y Gd y ) 3 (Al 1-z Ga z ) 5 O 12 :Ce 3+ [0≤y<1, 0≤z<1].

17. The projector according to claim 10 , wherein the second phosphor is a phosphor expressed by Lu 3 Al 5 O 12 :Ce 3+ .

18. The projector according to claim 10 , wherein the second portion contains at least part of the first phosphor and at least part of the second phosphor.

Assignees

• Panasonic Corp

Inventors

• Nagasaki Yoshihisa
• Ohbayashi Takashi
• Okuyama Kojiro

Classifications

• F21V13/14

  the elements being filters or photoluminescent elements, reflectors and refractors · CPC title

• F21V9/45

  by adjustment of photoluminescent elements · CPC title

• F21V9/38

  Combination of two or more photoluminescent elements of different materials · CPC title

• F21V9/32

  characterised by the arrangement of the photoluminescent material · CPC title

• F21S41/321

  the reflector being a surface of revolution or a planar surface, e.g. truncated · CPC title