| 摘要 |
A base end 12a of an arc tube unit 12 is inserted in a glass tube 50 which is previously fixed to an insulating plug unit 14, and a shroud tube 18 and the glass tube 50 are then bonded and fixed to each other in such a state that an amount of insertion of the arc tube unit 12 is regulated in order to set a dimension L between an optical reference plane Po of the insulating plug unit 14 and the tip position of a bar-shaped electrode 26B of an arc tube 16 to be a predetermined set dimension Lo. Consequently, the arc tube unit 12 can be fixed and supported on the insulating plug unit 14 with a simple structure in a simple process, and furthermore, it is possible to eliminate a possibility that the shroud tube 18 might be damaged, for example, broken by the fastening force of a metal band as in the conventional art. |
