Low-pressure mercury vapor discharge lamp
AssigneeU.S. Philips Corporation
InventorsAntonius M. J. H. Seuter, Petrus F. J. van den Boom
Life of this patent
Estimating the term…
Abstract
A low-pressure mercury vapor discharge lamp comprising a glass discharge envelope (1) in which during operation of the lamp a discharge is present and which contains mercury and a rare gas, at least a part of the inner wall of the discharge envelope being provided with a thin at least substantially homogeneous continuous transparent layer (4) which is resistent to the action of the discharge. According to the invention, this transparent layer (4) contains an oxide of at least one of the groups comprising yttrium, scandium, lanthanum, gadolinium, ytterbium and lutetium.
Claims8
A low-pressure mercury vapour discharge lamp comprising a glass discharge envelope containing mercury and a rare gas and in which during operation of the lamp a discharge is present and which contains mercury and a rare gas, characterized in that at least a part of the inner surface of the wall of the discharge envelope is provided with a thin, at least substantially homogeneous, continuous layer, resistant to the influence of the discharge, transparent to light and radiation from said discharge, and consisting essentially of an oxide consisting of oxygen and at least one of the elements selected from the group consisting of yttrium, scandium, lanthanum, gadolinium, ytterbium and lutetium.
Dependencies are inferred from the claim text.