| 摘要 |
A light bulb includes an enclosure (2), a heat-dissipating unit (3), and a lamp unit (4). The enclosure (2) extends along an axis (X) and defines an inner space (20) therein. The heat-dissipating unit (3) includes a hollow first heat-dissipating element (31) disposed in the inner space (20), a second heat-dissipating element (32) surrounded by the first heat-dissipating element (31), and extending along the axial direction (X), and an end heat-dissipating element (34) mounted to the second heat-dissipating element (32) at a distal end (321) thereof. The lamp unit (4) includes a first circuit board (41) disposed at a periphery of the first heat-dissipating element (31), a second circuit board (42) mounted on the end heat-dissipating element (3), and a plurality of light-emitting elements (43) mounted on the first and second circuit boards (41, 42) . |
