US 11,990,571 B2
Light emitting device
Makiko Iwasa, Anan (JP); and Kazushige Fujio, Tokushima (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Sep. 6, 2022, as Appl. No. 17/929,870.
Application 17/929,870 is a continuation of application No. 16/983,470, filed on Aug. 3, 2020, granted, now 11,502,226.
Application 16/983,470 is a continuation of application No. 16/426,918, filed on May 30, 2019, granted, now 10,770,628.
Claims priority of application No. 2018-105560 (JP), filed on May 31, 2018; and application No. 2019-095441 (JP), filed on May 21, 2019.
Prior Publication US 2023/0019657 A1, Jan. 19, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. H01L 33/50 (2010.01); A61L 2/08 (2006.01); H01L 33/56 (2010.01); H01L 33/60 (2010.01); H01L 33/32 (2010.01); H01L 33/48 (2010.01); H01L 33/62 (2010.01)
CPC H01L 33/504 (2013.01) [A61L 2/084 (2013.01); H01L 33/507 (2013.01); H01L 33/56 (2013.01); H01L 33/60 (2013.01); A61L 2202/11 (2013.01); H01L 33/32 (2013.01); H01L 33/486 (2013.01); H01L 33/62 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for producing a light emitting device, comprising:
preparing
a fluorescent member composition containing a resin, a first fluorescent material, a second fluorescent material, and a third fluorescent material, the first fluorescent material, the second fluorescent material, and the third fluorescent material each emitting light as excited by light emitted from a light emitting element having a light emission peak wavelength in a range of 380 nm to 420 nm, and being mixed to make a content of the first fluorescent material of 1.0% by mass or more and 50.0% by mass or less, a content of the second fluorescent material of 45.0% or more and 99.0% by mass or less, and a content of the third fluorescent material of 0% by mass or more and 50.0% by mass or less, relative to the total mass of the first fluorescent material, the second fluorescent material, and the third fluorescent material, and to make the light emitting device having a spectral distribution having a proportion of an integral value over a wavelength range of 380 nm to 420 nm of 15% or more when an integral value over a wavelength range of 380 nm to 780 nm is normalized to 100%; and
mounting the light emitting element on a molded body, and then arranging and curing the fluorescent member composition on the light emitting element, so as to form a fluorescent member,
wherein a correlated color temperature, as measured according to JIS Z8725, of the mixed light of the light of the light emitting element and the light of the fluorescent material is in a range of 2000 K or more and 7500 K or less, and
a ratio a as defined by the following expression (1) falling within a range of 0.9 to 1.6:

OG Complex Work Unit Math
wherein BS represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in a spectral distribution of a reference light source at the correlated color temperature of the light emitting device, Gs represents a maximum emission intensity in a wavelength range of 485 nm to 548 nm in the spectral distribution of the reference light source at the correlated color temperature of the light emitting device, and the denominator of the expression (1) is a ratio of Gs to Bs, and wherein BL represents a maximum emission intensity in a wavelength range of 430 nm to less than 485 nm in the spectral distribution of the light emitting device, GL represents a maximum emission intensity in a wavelength range of 485 nm to 548 nm in the spectral distribution of the light emitting device, and the numerator of the expression (1) is a ratio of GL to BL.