US 11,852,322 B2
Filament lamp with improved visibility
Ties Van Bommel, Horst (NL); and Rifat Ata Mustafa Hikmet, Eindhoven (NL)
Assigned to SIGNIFY HOLDING B.V., Eindhoven (NL)
Appl. No. 18/010,532
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Jun. 14, 2021, PCT No. PCT/EP2021/065876
§ 371(c)(1), (2) Date Dec. 15, 2022,
PCT Pub. No. WO2021/254923, PCT Pub. Date Dec. 23, 2021.
Claims priority of application No. 20180785 (EP), filed on Jun. 18, 2020.
Prior Publication US 2023/0258320 A1, Aug. 17, 2023
Int. Cl. F21V 19/00 (2006.01); F21K 9/64 (2016.01); F21K 9/232 (2016.01); F21Y 107/50 (2016.01); F21Y 115/10 (2016.01)
CPC F21V 19/002 (2013.01) [F21K 9/232 (2016.08); F21K 9/64 (2016.08); F21Y 2107/50 (2016.08); F21Y 2115/10 (2016.08)] 14 Claims
OG exemplary drawing
 
1. A light generating device comprising an LED filament, wherein the LED filament comprises a support, a set of solid state light sources, and an encapsulant, wherein:
the LED filament has a length axis having a first length;
the support supports a 1D array of solid state light sources at one side of the support;
the solid state light sources are arranged over the first length of the LED filament on the support, wherein the solid state light sources are configured to generate light source light;
the encapsulant encloses at least part of each of the solid state light sources of the set of solid state light sources, wherein the encapsulant comprises a luminescent material configured to convert at least part of the light source light into luminescent material light;
the light generating device is configured to generate device light comprising one or more of (i) the light source light and (ii) the luminescent material light;
for each of the solid state light sources of the set of solid state light sources applies that relative to a first virtual plane parallel to length axis and intersecting with the solid state light source the encapsulant is asymmetrically configured relative to the first virtual plane;
wherein the light generating device is configured to generate white device light, and wherein for a plurality of the solid state light sources applies that device light emanating away from each solid state light source in a third virtual plane perpendicular to the first virtual plane and perpendicular to the support in different directions has different correlated color temperatures, wherein a distribution of the correlated color temperatures is not symmetrical relative to the first virtual plane; and
wherein a lower correlated color temperature TL is at maximum 2500 K and wherein a higher correlated color temperature TH is at least 2300 K, wherein TL<TH, and wherein a difference between a higher correlated color temperature TH and a lower correlated color temperature TL is at least 300 K.