JPWO2020208009A5

JPWO2020208009A5 -

Info

Publication number: JPWO2020208009A5
Application number: JP2021559161A
Authority: JP
Publication date: 2023-04-14

Claims

A light emitting diode (LED) filament comprising:
an elongated substrate;
a plurality of light emitting diodes (LEDs) mechanically coupled to the substrate;
an at least partially optically transmissive encapsulant encapsulating the plurality of LEDs and at least partially encapsulating the substrate;
a plurality of at least partially light-reflective particles disposed on an outer surface of the encapsulant;
the particles of said at least partially light reflective particles comprising:
a first surface located in contact with the encapsulant;
a second surface opposite the first surface, the second surface facing away from the encapsulant ;
an LED filament,
the particles of said at least partially light-reflective particles having at least one flat surface and characterized by a longest dimension length L1, a shortest dimension length L2, and a further dimension length L3;
a first aspect ratio of the length of the longest dimension to the length of the shortest dimension, AR1=L1/L2, is in the range of 10 to 300, and a second aspect ratio of the length of the further dimension to the length of the shortest dimension; AR2=L3/L2 is in the range of 10 to 300, and a third aspect ratio of said longest dimension length and said further dimension length, AR3=L1/L3 is in the range of 0.3 to 3.
LED filament.

The longest dimension length L1 ranges from 0.1 to 3 mm, the further dimension length L3 ranges from 0.1 to 3 mm, and the shortest dimension length L2 ranges from 10 to 300 μm. The LED filament of claim 1, wherein:

3. The LED filament of claim 1 or 2 , wherein the LED filament has a diameter D and the longest dimension length L1 is in the range 0.1D-D.

4. The LED filament of any one of claims 1-3 , wherein the at least partially light reflective particles are rigid.

13. The at least partially light reflective particles are randomly distributed on the encapsulant and/or the at least partially light reflective particles are randomly oriented. 5. The LED filament according to any one of 4 .

6. Any of claims 1-5 , wherein a minimum LED filament coverage _Cmin , representing a minimum coverage of the at least partially light-reflective particles on the outer surface of the encapsulant, is 3%. The LED filament according to item 1.

The maximum LED filament coverage _Cmax , which represents the maximum coverage of the at least partially light reflective particles on the outer surface of the encapsulant, is determined by the at least partially light reflective particles being transmissive. and C _max =(T/50)×100 if the transmittance T of the at least partially light-reflective particles is less than 40%, or the maximum LED filament coverage C _max is 7. The LED filament of any one of claims 1 to 6 , wherein 30% when the at least partially light reflective particles are opaque.

8. The LED filament of any one of claims 1-7 , wherein the at least partially optically transmissive encapsulant comprises a wavelength converting material.

9. The LED filament of any one of claims 1 to 8 , wherein the particles of the at least partially light-reflective particles have a wavelength-dependent reflection coefficient.

10. The LED filament of any one of claims 1 to 9 , wherein the particles of at least partially light-reflective particles comprise multilayer reflectors or dichroic mirrors.

A lighting device,
at least one LED filament according to any one of claims 1 to 10 ;
an at least partially light transmissive envelope at least partially surrounding the at least one LED filament;
a base on which the at least partially light transmissive enclosure is mounted, the base including an electrical connector for connecting the lighting device to a light fixture socket.

a lighting fixture,
a socket;
12. A lighting fixture according to claim 11 , comprising a lighting device connected to said socket.