Abstract: 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.

Abstract: An elevation device is provided for a monitoring camera, including a top retaining barrel fixed to the top end of a high suspending post and downward fit onto a retained member. The retained member has a bottom forming the wire box. A retained cylinder has an outer circumference forming spaced locking blocks. The top retaining barrel comprises a locking tube receiving therein a toothed crown locking collar that comprises oppositely set first and second toothed crowns between when the locking blocks are movable to alternately carry out locking and unlocking operation. The locking tube forms a guide block corresponding to an inclined circumferential surface of a cam, whereby when the retained cylinder is driven upward in any orientation to fit into the locking tube, the inclined circumferential surface is guided by the guide block to correct orientation of the retained cylinder with respect to retained cylinder.

Abstract: An elevation device is provided for a monitoring camera, including a top retaining barrel fixed to the top end of a high suspending post and downward fit onto a retained member. The retained member has a bottom forming the wire box. A retained cylinder has an outer circumference forming spaced locking blocks. The top retaining barrel comprises a locking tube receiving therein a toothed crown locking collar that comprises oppositely set first and second toothed crowns between when the locking blocks are movable to alternately carry out locking and unlocking operation. The locking tube forms a guide block corresponding to an inclined circumferential surface of a cam, whereby when the retained cylinder is driven upward in any orientation to fit into the locking tube, the inclined circumferential surface is guided by the guide block to correct orientation of the retained cylinder with respect to retained cylinder.