| 摘要 |
<p>A polycrystalline ceramic arc for a high brightness discharge lamp having a frit-sealed portion having a ceramic of an average particle diameter smaller than that of a ceramic in other portions; and a method for manufacturing the polycrystalline ceramic arc which comprises a first calcination step (S5) of controlling the water content of a formed tube product to a value between 20 and 30 wt %, a step (S6) of immersing the tip portion i.e. the portion having a frit attached thereto of a capillary part of the tube into an aqueous solution of magnesium nitrate having a concentration of 0.06 to 0.9 mol/L, a step of a second calcination step (S7) of calcining the immersed product and a step (S8) of firing the calcined product in a hydrogen atmosphere at 1750 to 1900 °. The method allows manufacturing, without using a complicated process, an arc tube being improved in the strength of its capillary part without detriment to characteristics of the trunk part.</p> |
