# US 11,994,284 B2 · Wavelength conversion member and light source device provided therewith

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- Number: US 11,994,284 B2
- Document ID: US11994284B2
- Status: Granted
- Kind: B2
- Application number: 18/245,275
- Filed: 2021-12-13
- Published: 2023-11-30
- Granted: 2024-05-28
- Earliest claimed: 2021-01-28
- Assignees: Niterra Co., Ltd.
- Applicants: Ngk Spark Plug Co., Ltd.
- Inventors: Yosuke Yatsuya; Toshiyuki Sakurai; Shohei Takaku; Hiroki Yamauchi; Tomoo Tanaka; Hiroki Takeuchi; Shinji Ban
- Web page: https://patentgrep.com/patent/US11994284B2

## CPC

- F21V 7/30: the coatings comprising photoluminescent substances
- F21K 9/64: using wavelength conversion means distinct or spaced from the light-generating element, e.g. a remote phosphor layer
- F21V 9/30: 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)
- G02B 5/206: {comprising particles embedded in a solid matrix}
- G02B 5/26: Reflecting filters (G02B5/28 takes precedence)
- G02B 7/1815: {with cooling or heating systems (cooling arrangements for laser mirrors H01S3/0401)}
- G02B 2207/113: Fluorescence
- F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
- F21K: NON-ELECTRIC LIGHT SOURCES USING LUMINESCENCE; LIGHT SOURCES USING ELECTROCHEMILUMINESCENCE; LIGHT SOURCES USING CHARGES OF COMBUSTIBLE MATERIAL; LIGHT SOURCES USING SEMICONDUCTOR DEVICES AS LIGHT-GENERATING ELEMENTS; LIGHT SOURCES NOT OTHERWISE PROVIDED FOR
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

There is provided a wavelength conversion member including: a fluorescent body and a reflective film. The fluorescent body is configured to emit fluorescence by an excitation light and has an incident surface into which the excitation light comes and a rear surface which faces the incident surface. The reflective film is arranged on a side of the rear surface of the fluorescent body and includes a metal layer and ceramic particles dispersed in the metal layer. The ceramic particles are crystalline, and a melting point of the ceramic particles is higher than a melting point of a metal constructing the metal layer.

## Claims

### Claim 1

A wavelength conversion member comprising:
a fluorescent body configured to emit fluorescence by an excitation light and having an incident surface into which the excitation light comes and a rear surface which faces the incident surface; and
a reflective film arranged on a side of the rear surface of the fluorescent body and including a metal layer and ceramic particles dispersed in the metal layer,
wherein the ceramic particles are crystalline, and a melting point of the ceramic particles is higher than a melting point of a metal constructing the metal layer.

### Claim 2 (depends on 1)

The wavelength conversion member according to claim 1, wherein the ceramic particles are oxide particles.

### Claim 3 (depends on 1)

The wavelength conversion member according to claim 1, wherein the ceramic particles have a translucency.

### Claim 4 (depends on 1)

The wavelength conversion member according to claim 1, wherein the ceramic particles are oxide particles which is configured to emit a light by the excitation light.

### Claim 5 (depends on 1)

The wavelength conversion member according to claim 1, wherein the ceramic particles are particles of a ceramic sintered body constructing the fluorescent body.

### Claim 6 (depends on 1)

The wavelength conversion member according to claim 1, further comprising a heat-dissipating member which is arranged in the reflective film on a side opposite to the fluorescent body and which is configured to dissipate a heat of the fluorescent body.

### Claim 7 (depends on 6)

A light source apparatus comprising:
the wavelength conversion member as defined in claim 6; and
a light source configured to irradiate the incident surface of the fluorescent body with the excitation light.