US 11,817,530 B2
Light emitting device
Keisuke Sakai, Fujiyoshida (JP)
Assigned to Citizen Electronics Co., Ltd., Fujiyoshida (JP); and Citizen Watch Co., Ltd., Nishitokyo (JP)
Appl. No. 18/013,356
Filed by Citizen Electronics Co., Ltd., Fujiyoshida (JP); and Citizen Watch Co., Ltd., Nishitokyo (JP)
PCT Filed Jun. 28, 2021, PCT No. PCT/JP2021/024370
§ 371(c)(1), (2) Date Dec. 28, 2022,
PCT Pub. No. WO2022/004663, PCT Pub. Date Jan. 6, 2022.
Claims priority of application No. 2020-111283 (JP), filed on Jun. 29, 2020.
Prior Publication US 2023/0231082 A1, Jul. 20, 2023
Int. Cl. H01L 33/48 (2010.01); H01L 33/50 (2010.01); H01L 33/56 (2010.01)
CPC H01L 33/486 (2013.01) [H01L 33/502 (2013.01); H01L 33/56 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A light emitting device comprising:
a substrate;
a plurality of first light emitting elements mounted on the substrate, including first light emitting diode (LED) dies, and emitting light having a first wavelength; and
a light guide layer arranged so as to cover the plurality of first light emitting elements, and guiding the light from the plurality of first light emitting elements, wherein
when LG1 is a distance between the first LED dies, and θc is a critical angle of the light emitted from the light guide layer to air, and a thickness T between upper surfaces of the first light emitting elements and an upper surface of the light guide layer is equal to or longer than T1 indicated by
T1=LG1/(2 tan θc).