Patent ID: 8858041

Claim:
A lamp comprising: an outer shell with heat conductivity, wherein the outer shell includes a light source support, and a heat radiating surface exposed to an outside of the outer shell, wherein the light source support is formed integrally with the heat radiating surface; a base provided in the outer shell; a board on which a thermal diffusion layer is integrally stacked on a rear surface of the board, the rear surface of the board being fixed to the light source support, the board being fixed to the light source support through a screw at a center thereof such that the thermal diffusion layer is disposed between the board and the light source support, and being thermally connected to the light source support, wherein the thermal diffusion layer includes a plurality of areas, wherein each of the plurality of areas is at least partially divided from another one of the plurality of areas by a respective slit of a plurality of slits in the thermal diffusion layer, each slit extending from an outer peripheral edge of the thermal diffusion layer in a radial direction toward the center of the board; a plurality of heat generating light-emitting diodes mounted on the board at positions substantially evenly spaced from the center of the board so as to surround the screw; and a translucent cover provided in the outer shell so as to cover the light-emitting diodes, wherein at least one light-emitting diode is located entirely within an area of the board defined by a region of the thermal diffusion layer surrounded by two adjacent slits and an imaginary line connecting respective ends of the two adjacent slits, the respective ends of the two adjacent slits being ends closest to the center of the board, wherein a first slit of the two adjacent slits is disposed on a first circumferential side of the at least one light-emitting diode and a second slit of the two adjacent slits is disposed on a second circumferential side of the at least one light-emitting diode.