公开(公告)号：US20210376201A1

公开(公告)日：2021-12-02

申请号：US17303376

申请日：2021-05-27

Applicant: NICHIA CORPORATION

Inventor： Makiko IWASA ,  Kazuya NISHIMATA ,  Atsushi YOSHINARI ,  Shoji HOSOKAWA ,  Masato OKAWA ,  Yasuaki MASHIMA

IPC: H01L33/50 ,  F21K9/64 ,  C09K11/77

Abstract: A light emitting device includes a light emitting element having a dominant wavelength in a range of 400 nm or more and 500 nm or less, and a wavelength conversion member that is arranged on a light emitting side of the light emitting element and includes a rare earth aluminate fluorescent material having a composition represented by the following formula (I), wherein the light emitting device emits light having a dominant wavelength in a range of 475 nm or more and 500 nm or less, and wherein the light emitting device emits light having an S/P ratio of 6.5 or less derived from the formula (1), which is the ratio of a luminous flux in scotopic vision relative to a luminous flux in photopic vision: (Lu1-p-nLnpCen)3(Al1-mGam)5kO12  (I) wherein in the formula (I), Ln represents at least one rare earth element selected from the group consisting of Y, La, Gd, and Tb, and the parameters k, m, n, and p satisfy 0.95≤k≤1.05, 0.05≤m≤0.70, 0.002≤n≤0.050, and 0≤p≤0.30, respectively.