Phosphor element and lighting device

Patent metadata

Field	Value
Publication number	US-11635189-B2
Application number	US-202217577638-A
Country	US
Kind code	B2
Filing date	Jan 18, 2022
Priority date	Sep 28, 2018
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A phosphor element includes: a phosphor part having an incident face for excitation light, an opposing face opposing the incident face, and a side face, the phosphor part converting at least a part of the excitation light incident onto the incident face into a fluorescence and emitting the fluorescence from the incident face; an integral low refractive index layer on the side face and opposing face of the phosphor part and having a refractive index lower than that of the phosphor part; and an integral reflection film covering a surface of the low refractive index layer. The area of the incident face of the phosphor part is larger than the area of the opposing face.

First claim

The invention claimed is:

1. A phosphor element comprising:
a phosphor part including an incident face onto which an excitation light is made incident from outside said phosphor element, an opposing face opposing said incident face, and a side face, said phosphor part converting a part of said excitation light incident onto said incident face to a fluorescence and emitting said excitation light and said fluorescence from said incident face to the outside of said phosphor element,
an integral low refractive index layer, composed of a single material without a break, on said side face and said opposing face of said phosphor part, said low refractive index layer having a refractive index lower than a refractive index of said phosphor part,
an integral reflection film composed of a single material without a break and covering a surface of said low refractive index layer, and
a dispersing material dispersed in said phosphor part,
wherein an area of said incident face of said phosphor part is larger than an area of said opposing face,
a distance between said incident face of said phosphor part and said opposing face of said phosphor part is from 290 μm-1.0 mm, and
an inclination angle of said side face with respect to said incident face is from 25° to 49°.

2. The phosphor element of claim 1 , wherein said dispersing material comprises a ceramic dispersing material.

3. The phosphor element of claim 1 , further comprising a supporting substrate comprising a transmitting material transmitting said excitation light and said fluorescence on said incident face.

4. The phosphor element of claim 1 , further comprising a heat-dissipating substrate contacting said reflection film.

5. The phosphor element of claim 4 , wherein said heat-dissipating substrate comprises a material having a thermal conductivity of 200 W/mK or larger.

6. The phosphor element of claim 5 , wherein said heat-dissipating substrate comprises a metal or ceramics having a thermal conductivity of 200 W/mK or larger and 500 W/mK or smaller.

7. The phosphor element of claim 6 , wherein said metal comprises gold, silver, copper, aluminum or an alloy containing said metal.

8. The phosphor element of claim 6 , wherein said ceramics comprises silicon carbide or aluminum nitride.

9. An illumination device comprising:
a light source oscillating an excitation light; and
said phosphor element of claim 1 .

Assignees

• Ngk Insulators Ltd

Inventors

• Kondo Jungo
• Okada Naotake
• Iwata Yuichi
• Asai Keiichiro
• UNO Yudai

Classifications

• H10H20/856

  Reflecting means · CPC title

• H10H20/8514 Primary

  characterised by their shape, e.g. plate or foil · CPC title

• H01S5/0087

  for illuminating phosphorescent or fluorescent materials, e.g. using optical arrangements specifically adapted for guiding or shaping laser beams illuminating these materials · CPC title

• F21V7/26

  the material comprising photoluminescent substances · CPC title

• C09K11/7774

  Aluminates · CPC title