High pressure discharge lamp, high pressure discharge lamp lighting apparatus and luminaire therefor

A high pressure discharge lamp, comprising:

• a light-transmissive ceramic discharge vessel with an envelope and open ends;
• a metal pipe disposed in each of the open ends, respectively, each metal pipe having a first end located in a corresponding one of the open ends of the light-transmissive ceramic discharge vessel and a second end protruding from the light-transmissive ceramic discharge vessel;
• a plurality of electrodes each having a first end connected to a corresponding metal pipe and a second end extending within the light-transmissive ceramic discharge vessel;
• and
• a discharge agent which is filled in the light-transmissive ceramic discharge vessel,
• wherein an overall length L1 of the discharge lamp is less than 30 mm, and a temperature difference between a highest temperature portion and a lowest temperature portion is less than 400 degrees Celsius during operation of the lamp.

A high pressure discharge lamp, comprising;

• a light-transmissive ceramic discharge vessel with an envelope and two open ends;
• a metal pipe disposed in each of the open ends, respectively, each metal pipe being made of a metal having a melting point of T1, wherein a top end is fused in a corresponding one of the open ends in a first of the open ends of the light-transmissive ceramic discharge vessel, and a second end of the open ends protrudes from the light-transmissive ceramic discharge vessel;
• a fusing metal made of a metal having a melting point of T2 and configured to seal a base end of each metal pipe;
• a plurality of electrodes, whose base ends are coupled to each metal pipe via the fusing metal, and whose top end protrudes into the light-transmissive ceramic discharge vessel;
• and
• a discharge agent filled in the light-transmissive ceramic discharge vessel,
• wherein the melting point T1 of each metal pipe and the melting point T2 of the fusing metal satisfy an equation:
• T1>T2.