Patent ID: 8314537

Claim:
An electric lamp comprising: a bulb mounted on a socket, cooling means for cooling the lamp during operation, a semiconductor light source arranged inside the bulb, a lamp axis extending through a central end of the socket and a central extremity of the bulb, the bulb having an outer surface comprising a light transmittable surface for transmitting light originating from the light source during operation of the lamp, wherein both the cooling means and the light transmittable surface are spread over the bulb outer surface, such that for an imaginary set of two planes, of which a first plane extends parallel to the axis and a second plane extends perpendicular to the axis, a position of said planes can be found in which at least one of said two planes crosses at least two times a boundary between the cooling means and the light transmittable surface; said cooling means extending from inside the bulb to the outer surface of the bulb; said light transmittable surface divided into sub-areas by the cooling means; each of said sub-areas forming one integral light transmittable surface wherein the sub-areas and the cooling means are arranged in an alternating and interdigitated configuration extending axially over the length of the bulb; each sub-area surrounded by a respective part of the cooling means and each of said sub-areas separated by at least two axially extending cooling arches.