公开(公告)号：US20190316034A1

公开(公告)日：2019-10-17

申请号：US16463652

申请日：2017-12-04

Applicant: NGK Spark Plug Co., Ltd.

Inventor： Toshimitsu KIKUCHI ,  Yoshifumi TSUTAI ,  Takashi ABE ,  Ai HAYASAKA

IPC: C09K11/02 ,  C09K11/64

Abstract: A wavelength conversion member is provided which includes a phosphor layer having an increased pencil hardness and thereby has a reduced risk of breakage such as scattering of fragments of the phosphor layer or separation of the phosphor layer.A substrate 12 is made of sapphire, and a phosphor layer 14 is disposed on the substrate 12 and includes phosphor particles 16 and a light transmissive inorganic material 22. The phosphor layer 14 has a pencil hardness of 5B or above. The high hardness of the phosphor layer 14 reduces the risk of breakage such as the phosphor layer 14 being scattered as fragments or being separated from the substrate 12.