Illuminating device

1. An illuminating device, comprising:

a light source unit including a substrate and one or more light emitting devices disposed on the substrate; and

a heat radiating unit including a sealed inner space into which a working fluid is injected, the sealed inner space having a center hole penetrating the sealed inner space, the working fluid being evaporated and condensed within the inner space due to heat of the light source unit, such that the heat radiating unit emits the heat of the light source unit to the outside through repeated phase changes according to evaporation and condensation of the working fluid.

2. The illuminating device of claim 1 , wherein the heat radiating unit further includes:

a heat absorbing surface having the light source unit disposed thereon;

an inner side surface having one end connected to a center of the heat absorbing surface and the other end extending upwardly from the heat absorbing surface to penetrate the inner space, thereby forming the center hole; and

a heat radiating surface connecting the other end of the inner side surface with an outer circumference of the heat absorbing surface.

3. The illuminating device of claim 2 , wherein the heat radiating unit has a triangular cross sectional shape in which the heat radiating surface forms an inclined plane, based on the heat absorbing surface as a bottom surface.

4. The illuminating device of claim 2 , wherein the heat radiating surface includes a plurality of heat radiating fins protrudedly disposed on an outer surface of the heat radiating surface.

5. The illuminating device of claim 3 , wherein the heat radiating surface includes a plurality of heat radiating fins protrudedly disposed on an outer surface of the heat radiating surface.

6. The illuminating device of claim 2 , wherein the heat absorbing surface includes micro-channels on a surface of the heat absorbing surface exposed to the inner space.

7. The illuminating device of claim 3 , wherein the heat absorbing surface includes micro-channels on a surface of the heat absorbing surface exposed to the inner space.

8. The illuminating device of claim 2 , further comprising an electrical connection unit accommodated within the center hole to supply the light source unit with an electrical signal.

9. An illuminating device, comprising:

a light source unit including a substrate and one or more light emitting devices disposed on the substrate; and

a heat radiating unit including a sealed inner space into which a working fluid is injected, the working fluid being evaporated and condensed within the inner space due to heat of the light source unit, and emitting the heat of the light source unit to the outside through repeated phase changes according to evaporation and condensation of the working fluid, wherein:

the heat radiating unit further includes:

a heat absorbing surface having the light source unit disposed thereon;

an inner side surface having one end connected to the heat absorbing surface and the other end extending upwardly from the heat absorbing surface; and

a heat radiating surface connecting the other end of the inner side surface with an outer circumference of the heat absorbing surface, and

the heat radiating unit is a structure which has a triangular cross sectional shape in which the heat radiating surface forms an inclined plane, based on the heat absorbing surface used as a bottom surface.

10. The illuminating device of claim 9 , wherein the heat radiating surface includes a plurality of heat radiating fins protrudedly formed on an outer surface thereof

11. The illuminating device of claim 3 , wherein the heat absorbing surface includes micro-channels on a surface thereof exposed to the inner space.