| 摘要 |
<p>A high pressure discharge lamp in which, in the silica glass which comprises the hermetically sealed portion on the cathode side, fractures originating from the contact area with the cathode are prevented from propagating as in a high pressure discharge lamp of the direct current operating type which has: a discharge vessel (1) of silica glass in which opposite sides an arc tube portion are each joined to a respective hermetically sealed portion (1A,1B); a metal foil (2A,2B) is located in each of the hermetically sealed portions; a supply lead is attached in each the hermetically sealed portion with an inner end of the supply lead being connected to a respective one of the metal foils and an outer end projecting outwardly from the discharge vessel; an anode and a cathode are each attached in one of the hermetically sealed portions and have a base which is connected to one of the metal foils and a tip which projects into the arc tube portion; by the outer surface of the cathode-side hermetically sealed portion being surrounded by a conductive component (8) in the area (X) of the cathode (3A), and by the area of the outer surface in which the conductive component is located having microscopically small projecting glass surfaces (11) which do not contact the conductive component. <IMAGE></p> |
