Illumination light source, illumination apparatus, outdoor illumination apparatus, and vehicle headlight

Patent metadata

Field	Value
Publication number	US-2016377240-A1
Application number	US-201615184244-A
Country	US
Kind code	A1
Filing date	Jun 16, 2016
Priority date	Jun 26, 2015
Publication date	Dec 29, 2016
Grant date	—

Abstract

An illumination light source emits white light resulting from mixing of light emitted from an LED chip and light emitted from a plurality of phosphors. A light emission spectrum of the white light has a peak in a wavelength range from 430 nm to 460 nm. In the light emission spectrum, a proportion of optical intensity at a wavelength of 510 nm relative to optical intensity at the peak is 0.45 or more, and a proportion of optical intensity at a wavelength of 580 nm relative to the optical intensity at the peak is 0.60 or more. Furthermore, in the light emission spectrum, a proportion of optical intensity at a wavelength of 650 nm relative to the optical intensity at the wavelength of 580 nm is 0.4 or less.

First claim

What is claimed is:

1 . An illumination light source comprising:
a light-emitting element; and a plurality of phosphors each of which is excited by light emitted from the light-emitting element and emits light having a wavelength different from a wavelength of the light emitted from the light-emitting element, wherein the illumination light source emits white light resulting from mixing of the light emitted from the light-emitting element and the light emitted from the plurality of phosphors, a light emission spectrum of the white light has a peak in a wavelength range from 430 nm to 460 nm, in the light emission spectrum,
a proportion of optical intensity at a wavelength of 510 nm relative to optical intensity at the peak is 0.45 or more,
a proportion of optical intensity at a wavelength of 580 nm relative to the optical intensity at the peak is 0.60 or more, and
a proportion of optical intensity at a wavelength of 650 nm relative to the optical intensity at the wavelength of 580 nm is 0.4 or less,
a correlated color temperature of the white light is in a range from 4500 K to 7000 K, and an average color rendering index Ra of the white light is 70 or more.

2 . The illumination light source according to claim 1 ,
wherein the light-emitting element has a light emission peak in the wavelength range from 430 nm to 460 nm.

3 . The illumination light source according to claim 1 ,
wherein one of the plurality of phosphors has a center wavelength of fluorescence in a range from 540 nm to 550 nm.

4 . The illumination light source according to claim 1 ,
wherein the plurality of phosphors include a Lu 3 Al 5 O 12 :Ce 3+ phosphor having a center wavelength of fluorescence in a range from 540 nm to 550 nm.

5 . The illumination light source according to claim 1 ,
wherein one of the plurality of phosphors has a center wavelength of fluorescence in a range from 610 nm to 620 nm.

6 . The illumination light source according to claim 1 ,
wherein the plurality of phosphors include a (Sr, Ca)AlSiN 3 :Eu 2+ phosphor having a center wavelength of fluorescence in a range from 610 nm to 620 nm.

7 . The illumination light source according to claim 1 ,
wherein an S/P (scotopic/photopic) ratio of the white light is 2.0 or more, the S/P ratio being a ratio of scotopic luminance to photopic luminance.

8 . The illumination light source according to claim 2 ,
wherein a plurality of light-emitting elements are provided, each of the plurality of light-emitting elements being the light-emitting element having the light emission peak in the wavelength range from 430 nm to 460 nm.

9 . The illumination light source according to claim 8 ,
wherein only the plurality of light-emitting elements having the light emission peak in the wavelength range from 430 nm to 460 nm are provided as a light-emitting element.

10 . An illumination apparatus comprising:
the illumination light source according to claim 1 ; and a lighting apparatus that supplies the illumination light source with electric power for lighting the illumination light source.

11 . An outdoor illumination apparatus comprising:
the illumination light source according to claim 1 ; and a housing accommodating the illumination light source.

12 . A vehicle headlight, comprising the illumination light source according to claim 1 .

Assignees

• Panasonic Ip Man Co Ltd

Inventors

• Takei Naoko

Classifications

• H10W90/753

  between laterally-adjacent chips · CPC title

• H10W74/00

  Encapsulations, e.g. protective coatings · CPC title

• H10W90/00

  Package configurations · CPC title

• F21S8/085

  of high-built type, e.g. street light · CPC title

• F21V29/77

  with essentially identical diverging planar fins or blades, e.g. with fan-like or star-like cross-section · CPC title