Extra-high pressure mercury lamp and method of manufacturing extra-high pressure mercury lamp of the same

Abstract

A lighting mode of an extra-high pressure mercury lamp can be switched between a steady lighting mode and a low electric power lighting mode. A temperature maintaining portion that absorbs light emitted from a light emission section is provided in a vicinity of a boundary between a sealing portion and a light emission section in an outer circumference direction of the lamp. The temperature maintaining portion is made of a material having thermal expansion coefficient that is greater than a material that forms the light emission section. The temperature maintaining portion comes in contact with the light emission section in the low electric power lighting mode. In the steady lighting mode, a gap is formed between the temperature maintaining portion and the light emission section so that the temperature maintaining portion is separated from the light emission section.

Dependencies are inferred from the claim text.