High-intensity discharge lamp lighting device and lighting system

A high-intensity discharge lamp lighting device, comprising:

• a high-intensity discharge lamp containing;
• a light-transmissive discharge enclosure having an envelope defining a discharge space;
• a hollow member having an inner diameter smaller than said envelope;
• an elongate electrode being inserted into said hollow member of said light-transmissive discharge enclosure leaving a narrow gap from the inner wall of said hollow member and having a leading end protruding into said hollow member of said light-transmissive discharge enclosure;
• a lead-conductor having a leading end coupled to a base end of said electrode;
• a middle portion attached to said light-transmissive discharge enclosure;
• a base end exposing outward from said light-transmissive discharge enclosure;
• and
• a discharge agent including at least neon and argon at a charged gas pressure in a range of 50-580 torr and filled into said light-transmissive discharge enclosure;
• and
• a lighting circuit means having a load characteristic close to a discharge starting voltage of said high-intensity discharge lamp and continuous from a secondary open-circuit voltage to a secondary short-circuit current for lighting said high-intensity discharge lamp at a high-frequency, wherein said high intensity discharge lamp has a light-transmissive ceramic discharge enclosure having an envelope defining a discharge space and a small diameter cylinder portion defining a hollow member having an inner diameter smaller than said envelope, an elongate electrode being inserted into said hollow member of said light transmissive ceramic discharge enclosure leaving a narrow gap from the inner wall of said hollow member and having a leading end protruding into said hollow member of said light transmissive ceramic discharge enclosure, a lead conductor having a leading end coupled to a base end of said electrode for supporting said electrode and a base end exposing outward from said light-transmissive ceramic discharge enclosure, a sealing compound for sealing ceramics sealing said small diameter cylinder portion of said light-transmissive ceramic discharge lamp and said leading conductor together, and discharge agent including at least neon and argon and filled into said light transmissive ceramic discharge enclosure.