US 12,297,968 B2
LED filament for emitting directional light
Ties Van Bommel, Horst (NL)
Assigned to SIGNIFY HOLDING, B.V., Eindhoven (NL)
Appl. No. 18/566,700
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed May 30, 2022, PCT No. PCT/EP2022/064551
§ 371(c)(1), (2) Date Dec. 4, 2023,
PCT Pub. No. WO2022/253735, PCT Pub. Date Dec. 8, 2022.
Claims priority of application No. 21177694 (EP), filed on Jun. 4, 2021.
Prior Publication US 2024/0263751 A1, Aug. 8, 2024
Int. Cl. F21K 9/238 (2016.01); F21K 9/68 (2016.01); F21V 9/30 (2018.01); F21Y 103/10 (2016.01); F21Y 107/00 (2016.01); F21Y 113/17 (2016.01); F21Y 115/10 (2016.01)
CPC F21K 9/68 (2016.08) [F21K 9/238 (2016.08); F21V 9/30 (2018.02); F21Y 2103/10 (2016.08); F21Y 2107/00 (2016.08); F21Y 2113/17 (2016.08); F21Y 2115/10 (2016.08)] 15 Claims
OG exemplary drawing
 
1. A light-emitting diode (LED) filament configured to provide LED filament light and comprising:
an elongated carrier comprising a first elongated edge portion and a second elongated edge portion arranged at a distance (W1) from said first elongated edge portion, a first surface, a second surface arranged opposite to said first surface, said first and said second surfaces being delimited by said first and said second edge portions;
a plurality of first light-emitting diodes, LEDs, distributed along said first surface of said elongated carrier, the plurality of first LEDs being configured to emit a first LED light;
a first at least partially light-transmissive elongated layer encapsulating or covering said plurality of first LEDs and at least partially encapsulating or covering said first surface of said elongated carrier;
a second elongated reflective layer arranged to asymmetrically encapsulate or cover a portion of said first at least partially light-transmissive elongated layer,
wherein said plurality of first LEDs is arranged at a distance S from said first elongated edge portion of said elongated carrier,
wherein said plurality of first LEDs is arranged asymmetrically on said first surface of said elongated carrier, such that S≠W1/2,
wherein said second elongated reflective layer has a width (W2) measured from said first edge portion of said elongated carrier, wherein the ratio W2/W1 is from 0.3 to 0.8, and
wherein said first at least partially light-transmissive elongated layer is at least partially translucent, and said second elongated reflective layer is free from a light-converting material.