High intensity discharge lamp and lighting system using the same

摘要

To provide a high-efficiency and long-life high intensity discharge lamp that is obtained by a configuration in which a neon gas or a neon-based gaseous mixture is filled as a starting-assistance rare gas for an alumina ceramic arc tube, and a filling pressure is set to 13 kPa or more. The high intensity discharge lamp is provided with the alumina ceramic arc tube (1) having a discharge arc tube (3), alumina ceramic narrow tubes (4,5) formed at both end portions of the discharge arc tube (3), electrodes (6,7) and power feeders (12,13), the electrodes (6,7) and the power feeders (12,13) being arranged to form spaces (17,18) in the narrow tubes (4,5). The discharge arc tube (3) is filled with the neon gas or the neon-based gaseous mixture as the starting-assistance rare gas at a filling pressure of 13 kPa or more. This prevents a discharge arc from jumping from tip portions of the electrodes to the spaces (17,18) at starting of the lamp, and avoids occurrence of cracks and breakages in the narrow tubes (4,5). Therefore, it is possible to offer a high-efficiency and long-life high intensity discharge lamp.