Discharge lamp
AssigneeJapan Storage Battery Co., Ltd.
InventorsYasaburo Takeji, Shinji Taniguchi
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Abstract
An arc tube 6 of discharge lamp comprises a main tube body 11 of translucent ceramic sealed with a terminal plate 13 at both ends thereof. The main tube body 11 comprises integrally a large diameter portion 11A, a tapered portion 11B which is disposed at both sides of the large diameter portion 11A and has a smaller diameter toward the forward end thereof, and a small diameter portion 11C connected to the forward end of the tapered portion 11B. The curvature radius R of the border of the tapered portion 11B with the small diameter portion 11C is not smaller than 2 mm.
Claims4
A discharge lamp comprising an arc tube of translucent ceramic dosed with a metal halide and electrodes provided in said arc tube whereby discharge occurs across said electrodes, characterized in that a main tube body of said arc tube comprises a large diameter portion, a tapered portion which is disposed at both sides of said large diameter portion and has a smaller diameter toward the forward end thereof and a small diameter portion connected to the forward end of said tapered portions, and said tapered portion and said small diameter portion are connected to each other with a border having a curvature radius of not smaller than 2 mm.
Dependencies are inferred from the claim text.