LED filament and light bulb using the same

An LED light bulb, comprising:

• a bulb shell having a central axis;
• a lamp base connected to the bulb shell and substantially being coaxial with the bulb shell;
• a stem comprising a stand having two ends, disposed in the bulb shell along the central axis of the bulb shell;
• at least one first buffer member disposed in the bulb shell and connected to a first end of the stand;
• a second buffer member disposed in the bulb shell and connected to a second end of the stand;
• a driving circuit disposed in the lamp base and electrically connected to the first buffer member, the second buffer member and the lamp base;
• and
• at least one flexible LED filament being bent in a space curved shape in the bulb shell and electrically connected to the first buffer member and the second buffer member, the flexible LED filament comprising:
• a base layer;
• a plurality of LED chips disposed on the base layer and electrically connecting in series by first wires;
• two electrodes disposed on the base layer and respectively at two ends of the base layer, the two electrodes electrically connecting the plurality of LED chips by two second wires, the two electrodes electrically connected to the first buffer member and the second buffer member respectively;
• a top layer covering the plurality of LED chips, the first wires, the second wires and a portion of each of the two electrodes;
• and
• a layer body comprising a chromogenic particles and covering the top layer,
• wherein the flexible LED filament being bent in a space curved shape in the bulb shell around the central axis of the bulb shell and extends along the axial direction of the central axis,
• wherein at any point of the flexible LED filament the top layer is closer to the central axis of the bulb shell than the base layer.