ONE-SIDE ATTACHING TYPE ELECTRIC BULB

摘要

PURPOSE: To avoid the occurrence of non-uniform lighting caused by the converging action of the pump tube separation portion on a bulb apex in the center portion of a lighting area or in the vicinity of the center portion periphery when an one-side installation type lamp is used in a luminaire or a light projector. CONSTITUTION: In an one-side installation type discharge lamp 21, a bulb apex 25 including a pump tube separation portion 26 is delustered, for instance, by sand blasting. By delustering, the bulb apex 25 and the pump tube separation portion 26 are equipped with only a translucent portion having no directivity so that a converging action producing the obstructive luminous intensity maximum value is extinguished.