Led filament and led light bulb

An LED filament, comprising:

• a plurality of LED filament units, each of the plurality of LED filament units includes a LED chip with an upper surface and a lower surface opposite to the upper surface of the LED chip, and
• a light conversion layer comprising a top layer and a base layer, and the base layer comprises an upper surface and a lower surface opposite to the upper surface of the base layer, where the top layer with an upper surface and a lower surface opposite to the upper surface of the top layer is disposed on at least two sides of the LED chips, the lower surface of the LED chips is close to the upper surface of the base layer, and the upper surface of the top layer is away from the LED chips;
• wherein W1 represents the width of the upper surface of the base layer or the width of the lower surface of the top layer in the short axial direction of the LED filament, and H represents the distance from the upper surface of each of the LED chips to the upper surface of the top layer, and C represents the length of the LED filament unit in the longitudinal direction of the LED filament, wherein H is between b and 2.9C, b represents the maximum of 0.14C and 0.28W1.

An LED filament, comprising:

• a plurality of LED filament units, each of the plurality of LED filament units includes a LED chip with an upper surface and a lower surface opposite to the upper surface of the LED chip, and
• a light conversion layer comprising a top layer and a base layer, and the base layer comprises an upper surface and a lower surface opposite to the upper surface of the base layer, where the top layer with an upper surface and a lower surface opposite to the upper surface of the top layer is disposed on at least two sides of each of the LED chips, the lower surface of each of the LED chips is close to the upper surface of the base layer, and the upper surface of the top layer is away from each of the LED chips;
• wherein W1 represents the width of the upper surface of the base layer or the width of the lower surface of the top layer in the short axial direction of the LED filament, and H represents the distance from the upper surface of each of the LED chips to the upper surface of the top layer, and C represents the length of the LED filament unit in the longitudinal direction of the LED filament, wherein C is between g and 6.92H, where g represents the maximum value of 0.34H and 0.1W1.

An LED filament, comprising:

• a plurality of LED filament units, each of the plurality of LED filament units includes a LED chip with an upper surface and a lower surface opposite to the upper surface of the LED chip, and
• a light conversion layer comprising a top layer and a base layer, and the base layer comprises an upper surface and a lower surface opposite to the upper surface of the base layer, where the top layer with an upper surface and a lower surface opposite to the upper surface of the top layer is disposed on at least two sides of each of the LED chips, the lower surface of each of the LED chips is close to the upper surface of the base layer, and the upper surface of the top layer is away from each of the LED chips;
• wherein W1 represents the width of the upper surface of the base layer or the width of the lower surface of the top layer in the short axial direction of the LED filament, and H represents the distance from the upper surface of each of the LED chips to the upper surface of the top layer, and C represents the length of the LED filament unit in the longitudinal direction of the LED filament, wherein W1 is between 1.1W2 and e, where e represents the minimum value of 10C and 3.46H.