	US 12,082,318 B2
	Color temperature controllable led filament lamp providing improved light quality
Ties Van Bommel, Horst (NL); Rifat Ata Mustafa Hikmet, Eindhoven (NL); and Johannes Petrus Maria Ansems, Hulsel (NL)
Assigned to SIGNIFY HOLDING, B.V., Eindhoven (NL)
Appl. No. 17/918,921
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Apr. 12, 2021, PCT No. PCT/EP2021/059430 § 371(c)(1), (2) Date Oct. 14, 2022, PCT Pub. No. WO2021/209382, PCT Pub. Date Oct. 21, 2021.
Claims priority of application No. 20169879 (EP), filed on Apr. 16, 2020.
Prior Publication US 2023/0300958 A1, Sep. 21, 2023
Int. Cl. H05B 45/20 (2020.01); H05B 45/325 (2020.01); H05B 45/3577 (2020.01); H05B 47/11 (2020.01); H05B 47/155 (2020.01); H05B 47/19 (2020.01)

CPC H05B 45/20 (2020.01) [H05B 45/3577 (2020.01)]

15 Claims

1. A lighting device comprising:

at least one first light-emitting diode, LED, filament adapted to emit light with a first correlated color temperature, CCT;

at least one second LED filament adapted to emit light with a second CCT, different from said first CCT;

wherein each of said first and second LED filament has a first side and a second side being arranged opposite to each other and extending along a direction of elongation of each of the first and second LED filament and wherein each LED filament is arranged to emit a first, larger, portion of light from its first side and a second, smaller, portion of light from its second side;

a base connectable with a luminaire socket; and

an at least partially light-transmissive envelope being mounted on said base and at least partially enveloping said at least one first LED filament and said at least one second LED filament;

wherein a longitudinal axis (A) extends from said base to a top portion of said envelope;

wherein each of said at least one first LED filament is arranged at a first angle (θ₁) from said longitudinal axis, with its first side generally facing towards the top portion of the envelope; and

wherein each of said at least one second LED filament is arranged at a second angle (θ₂) from said longitudinal axis, with its first side generally facing towards the base.