US 12,281,760 B2
LED filament with elevated phosphor layer for flame appearance
Ties Van Bommel, Horst (NL)
Assigned to SIGNIFY HOLDING B.V., Eindhoven (NL)
Appl. No. 18/572,239
Filed by SIGNIFY HOLDING B.V., Eindhoven (NL)
PCT Filed Jun. 20, 2022, PCT No. PCT/EP2022/066704
§ 371(c)(1), (2) Date Dec. 20, 2023,
PCT Pub. No. WO2022/268700, PCT Pub. Date Dec. 29, 2022.
Claims priority of application No. 21180916 (EP), filed on Jun. 22, 2021.
Prior Publication US 2024/0369196 A1, Nov. 7, 2024
Int. Cl. F21K 9/64 (2016.01); F21K 9/232 (2016.01); F21K 9/238 (2016.01); F21Y 103/10 (2016.01); F21Y 113/17 (2016.01); F21Y 115/10 (2016.01)
CPC F21K 9/64 (2016.08) [F21K 9/232 (2016.08); F21K 9/238 (2016.08); F21Y 2103/10 (2016.08); F21Y 2113/17 (2016.08); F21Y 2115/10 (2016.08)] 12 Claims
OG exemplary drawing
 
1. A light emitting diode, LED, filament configured to provide LED filament light and comprising:
an elongated carrier extending in a lengthwise direction of said LED filament, said elongated carrier comprising a first major surface;
a plurality of LEDs arranged on said first major surface of said elongated carrier, and configured to emit LED light;
a first elongated translucent layer encapsulating or covering said plurality of LEDs and at least partly encapsulating or covering said first major surface of said elongated carrier, said first elongated translucent layer is substantially free from a luminescent material and comprises light scattering particles, said first elongated translucent layer having a width, W1, transverse to said lengthwise direction;
a second elongated translucent layer comprising a first luminescent material configured to partly convert said LED light into converted light, the second elongated translucent layer is arranged on an outer surface of said first elongated translucent layer, such that the second elongated translucent layer is contained within the width, W1, of the first elongated translucent layer; and wherein LED light is allowed to escape the LED filament from the sides of the first elongated translucent layer which is not covered by the second elongated translucent layer and wherein the LED filament light comprises part of the LED light and the converted light,
wherein the carrier and the first and second elongated translucent layers are flexible, and
wherein 5-40% of the LED light escapes the LED filament at the first elongated translucent layer.