Lighting device and lighting fitting null of ceramic discharge lamp and discharge

摘要

PURPOSE: To hold high color rendering performance, light emitting efficiency, and joint strength for a long time by optimaly regulating mix rate of crystal bodies of A1₂O₃-CaO based glass solder by a peak ratio in X-ray crystal diffraction angle. ;CONSTITUTION: A discharge lamp comprises sealing bodies 3a, 3b to which electrodes 6 connected to the aperture end parts of a light emitting tube bulb 2 via Al₂O₃-CaO based glass solders 4a, 4b, 7a, 7b are attached and a light emitting material containing sodium and rate gas is sealed therein. Mixing rate of crystal bodies of CaO.Al₂O₃, 3CaO.Al₂O₃, and 12CaO.7Al₂O₃ of the glass solder is set to the second peak of 12CaO.7Al₂O₃/the first peak of CaO.Al₂ O₃≤0.2, or the second peak of 12CaO.7Al₂O₃/the second peak of 3CaO.Al₂ O₃≤0.2 in a peak ratio in X-ray fraction angle. Reaction with sodium can thus be prevented so as to provide stable life characteristics.;COPYRIGHT: (C)1996,JPO