Lamp device of high heat dissipation efficiency

A lamp device comprising:

• a seat electrically connected to an external power source;
• and
• a heat dissipation assembly connected to the seat and being rotatable with respect to the seat;
• one end of the heat dissipation assembly having light emitting elements electrically connected to the seat;
• wherein the seat further including:
• a body;
• a head installed at an upper end of the body for electrically connecting an external power source;
• an electric joint downwards extending from the head;
• the heat dissipation assembly further including:
• a heat dissipating mask being connected to the body;
• and the heat dissipating mask being rotatable with respect to the body;
• a conductive unit installed in the heat dissipating mask;
• the conductive unit being electrically connected to the electric joint even when the heat dissipating mask rotates with respect to the body;
• and
• a lamp set driven electrically and installed in the heat dissipating mask;
• the lamp set being retained to the conductive unit through the heat dissipating mask.