Bandpass filter for use in light emitting device and light emitting device using the same

摘要

Provided is a bandpass filter for a light emitting device that can improve the light emission efficiency in use for a light emitting device, and a light emitting device that can obtain the high light emission efficiency by using the bandpass filter. The light emitting device includes a substrate; a light emitting element disposed over the substrate; a phosphor-containing layer containing at least one kind of phosphor; and a bandpass filter disposed over a surface of the phosphor-containing layer on the light emitting element side, the bandpass filter including a multilayer film having a plurality of first and second dielectric layers, the second dielectric layer being disposed over the first dielectric layer. The bandpass filter has a transmittance of 60% or more for light having a light emission peak wavelength of the light emitting element at an incident angle of 0 to 85°, and another transmittance of 40% or less for light having a light emission peak wavelength of at least one kind of phosphor at an incident angle of a Brewster's angle (θb)+5° (θb+5°) to 85° of the bandpass filter.

主权项

1. A light emitting device, comprising:
a substrate; a resin package disposed on the substrate, the resin package comprising a light-reflective resin; a light emitting element that is laterally surrounded by the resin package such that the resin package contacts lateral surfaces of the light emitting element; a phosphor-containing layer containing at least one kind of phosphor; and a bandpass filter disposed between the phosphor-containing layer and the light emitting element, wherein the bandpass filter is laterally surrounded by the resin package such that the resin package contacts lateral surfaces of the bandpass filter, and wherein the bandpass filter comprises a multilayer film including a plurality of first and second dielectric layers, the second dielectric layer being disposed over the first dielectric layer, wherein the bandpass filter has a transmittance of 60% or more for light having a light emission peak wavelength of the light emitting element at an incident angle in a range of 0 to 85° , and wherein the bandpass filter has a transmittance of 40% or less for light having a light emission peak wavelength of the at least one kind of phosphor at an incident angle in a range of a Brewster's angle (θb) of the bandpass filter +5°(θb +5°) to 85°.