Patent ID: 6583551
Filing Date: 2003-06-24
Classification: H01J,Y02B

Abstract:
A low-pressure mercury vapor discharge lamp comprising a light-transmitting discharge vessel (10),said discharge vessel (10) enclosing, in a gastight manner, a discharge space (11) provided with a filling of mercury and a rare gas, at least a part of an inner wall of the discharge vessel (10) being provided with a transparent layer (16), characterized in that the discharge vessel (10) is made from a glass comprising silicon dioxide and sodium oxide, with the glass composition comprising the following essential constituents, given in percentages by weight (wt. %): SiO260-80 wt. %,Na2O10-20 wt. %,and in that the transparent layer (16) comprises a borate and/or a phosphate of an alkaline earth metal and/or of scandium, yttrium or a further rare earth metal.