摘要
An LED light bulb, comprising: a lamp housing, a bulb base, connected with the lamp housing; a stem with a stand extending to the center of the lamp housing, disposed in the lamp housing; a single flexible LED filament, disposed in the lamp housing, points of the flexible LED filament in an xyz coordinates are defined as X, Y, and Z, an x-y plane of the xyz coordinates is perpendicular to the height direction of the light bulb, a z-axis of xyz coordinates is parallel with the stem, the filament is bent into spiral in an axial direction, the diameter of the outer spiral coil of the filament is large than the diameter of the intermediate spiral coil of the LED filament in the YZ plane.