Patent ID: 8430528

Claim:
An LED bulb comprising: a connector for being electrically connected to a power supply; a heat sink disposed on the connector, the heat sink comprising a tubular body defining a through hole at a center thereof, a plurality of fins extending inwardly from an inner circumference of the tubular body, and a supporting body located in the tubular body and connecting with inner edges of the fins, wherein the fins are spaced from each other, and a passage is defined between every two neighboring first fins, and wherein the tubular body defines a plurality of through grooves divided into a first group and a second group, the first group of the through grooves communicating an outer environment with the through hole; an LED module mounted on the supporting body of the heat sink and defining a through hole communicating with the through hole of the tubular body, the second group of the through grooves communicating with the through hole of the LED module via the passage; an envelope secured to the heat sink and covering the LED module; and a fan received in the tubular body, when the fan is driven to generate an airflow, the airflow first flowing from the outer environment to enter the central hole of the tubular body via the first group of the through grooves, then flowing through the central hole of the LED module to enter the envelope, and finally leaving the envelope through the passage and the second group of the through grooves to return to the outer environment.