US 11,959,632 B2
Light-emitting device, electronic device, and method for using light-emitting device
Mitsuru Nitta, Kyoto (JP); Shozo Oshio, Osaka (JP); and Takeshi Abe, Osaka (JP)
Assigned to Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
Appl. No. 17/418,278
Filed by Panasonic Intellectual Property Management Co., Ltd., Osaka (JP)
PCT Filed Dec. 18, 2019, PCT No. PCT/JP2019/049558
§ 371(c)(1), (2) Date Jun. 25, 2021,
PCT Pub. No. WO2020/137731, PCT Pub. Date Jul. 2, 2020.
Claims priority of application No. 2018-245494 (JP), filed on Dec. 27, 2018.
Prior Publication US 2022/0090759 A1, Mar. 24, 2022
Int. Cl. F21V 9/30 (2018.01); A61B 5/00 (2006.01); A61N 5/06 (2006.01); A61N 5/067 (2006.01); A61B 1/04 (2006.01); A61B 1/06 (2006.01); F21W 131/20 (2006.01); F21Y 115/30 (2016.01)
CPC F21V 9/30 (2018.02) [A61B 5/0071 (2013.01); A61N 5/062 (2013.01); A61N 5/067 (2021.08); A61B 1/043 (2013.01); A61B 1/0653 (2013.01); F21W 2131/20 (2013.01); F21Y 2115/30 (2016.08)] 17 Claims
OG exemplary drawing
 
1. A light-emitting device comprising:
a light source that radiates a primary light; and
a first phosphor that absorbs the primary light and converts the primary light into a first wavelength-converted light having a longer wavelength than the primary light, wherein:
the primary light is a laser light,
the first wavelength-converted light includes fluorescence based on electron energy transition of Cr3+, the fluorescence having an afterglow of more than 10 μs based on a parity-forbidden transition,
a fluorescence spectrum of the first wavelength-converted light has a maximum fluorescence intensity value in region of a wavelength exceeding 710 nm, and
the light source is a solid-state light-emitting element with a rated light output of 1 W or more, wherein saturation of the fluorescence based on the parity-forbidden transition of Cr3+ is less likely to occur under excitation by the primary light relative to saturation of fluorescence based on a parity-allowed transition of Ce3+ or Eu2+ having an afterglow of 10 μs or less.