Invention Grant
US09518718B2 Bandpass filter for use in light emitting device and light emitting device using the same 有权
用于发光器件的带通滤波器和使用其的发光器件

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