US 12,457,878 B2
Light-emitting device having double-sided light emissiion for reducing a difference in light emitted from different light emission direction
Tazuko Kitazawa, Sakai (JP)
Assigned to SHARP KABUSHIKI KAISHA, Sakai (JP)
Appl. No. 17/912,494
Filed by SHARP KABUSHIKI KAISHA, Sakai (JP)
PCT Filed Apr. 28, 2020, PCT No. PCT/JP2020/018179
§ 371(c)(1), (2) Date Sep. 17, 2022,
PCT Pub. No. WO2021/220431, PCT Pub. Date Nov. 4, 2021.
Prior Publication US 2023/0125204 A1, Apr. 27, 2023
Int. Cl. H10K 59/38 (2023.01); H10K 50/115 (2023.01); H10K 50/125 (2023.01); H10K 50/15 (2023.01); H10K 50/16 (2023.01); H10K 59/80 (2023.01)
CPC H10K 59/38 (2023.02) [H10K 50/115 (2023.02); H10K 50/125 (2023.02); H10K 50/15 (2023.02); H10K 50/16 (2023.02); H10K 59/80524 (2023.02)] 10 Claims
OG exemplary drawing
 
1. A light-emitting device configured to emit light in a first direction and also emit light in a second direction opposite the first direction, the light-emitting device comprising:
a first light-emitting layer configured to emit light of a first color;
a second light-emitting layer configured to emit light of a second color different from the first color;
a first electrode pair including a pair of a first anode electrode and a first cathode electrode; and
a second electrode pair being different from the first electrode pair and including at least a pair of a second anode electrode and a second cathode electrode, wherein:
in the first electrode pair,
a first electron transport layer is located on a first cathode electrode side, and
a first hole transport layer is located on a first anode electrode side and overlaps the first electron transport layer;
the first light-emitting layer is included between the first electron transport layer and the first hole transport layer,
the first light-emitting layer and the second light-emitting layer overlap each other as viewed from the first direction,
a first optical filter overlaps the first light-emitting layer and the second light-emitting layer as viewed from the first direction, and is located closer to a first direction side than the first light-emitting layer and the second light-emitting layer,
a second optical filter overlaps the first light-emitting layer and the second light-emitting layer as viewed from the second direction, and is located closer to a second direction side than the first light-emitting layer and the second light-emitting layer,
the first optical filter has an optical characteristic different from an optical characteristic of the second optical filter,
the first light-emitting layer is included only between the first electrode pair,
the second light-emitting layer is included only between the second electrode pair,
the first optical filter further has a transmittance proportional to an inverse of a maximum intensity of light in the first direction, and
the second optical filter has a transmittance proportional to an inverse of a maximum intensity of light in the second direction.