Patent ID: 8704431

Claim:
A discharge lamp adapted to be mounted in a holding member, comprising: a glass member that forms a light emitting part; a base member that is coupled to the glass member and is adapted to be detachably held by the holding member; and a second base member coupled to the glass member at a position that is different from that of the base member, wherein the second comprises a shaft part, a cover that covers the surface of the shaft part, and a conduit that is provided between the shaft part and the cover, and wherein the base member comprises: a contact part that defines a position of the light emitting part with respect to the holding member in a first direction when contacting the holding member; an urging part, which is configured to be urged by an external pressing force that presses the contact part to the holding member in the first direction when the discharge lamp is mounted in the holding member; a mating part that is provided between the contact part and the urged part and the mates with the holding member; and a groove part that is provided in the mating part and that, along with the holding member, constitutes a continuous cooling medium conduit that extends from the vicinity of the contact part to the urged part to allow gas to be introduced to the mating part in the vicinity of the contact part and to exit the mating part in the vicinity of the urging part, wherein the base member and the second base member are electric power receiving parts that correspond to different polarities in order to receive the supply of electric power for the lighting of the discharge lamp, and wherein the second base member comprises a service receiving terminal to which both electric power for lighting the discharge lamp and the cooling medium are supplied.