Abstract: The electric lamp comprises a lamp vessel (1) in which an electric element (2) is arranged. The electric element (2) is connected to feedthroughs (3, 4) that extend through the wall of the lamp vessel (1). The respective feedthroughs (3, 4) comprise a metal shell (7) and an internal current conductor (13) connected thereto. The metal shell (7), which has no knife edge, clamps around the neck-shaped end portion (5, 6) of the lamp vessel (1), hence realizing the gastightness of the feedthrough.

Abstract: A novel type of glass having a low sodium content (<0.1 wt. % Na.sub.2 O), which can be used as a bulb glass (10) for "TL" lamps and for compact fluorescent lamps. Said glass is free of the toxic and/or corrosive components PbO, F, As.sub.2 0.sub.3 and Sb.sub.2 0.sub.3. Apart from favorable properties as regards phosphor poisoning and mercury absorption, resulting in a favorable maintenance of the lamp, said glass is characterized by a wide working range W.R. (=T.sub.work -T.sub.soft), so that glass tubing can be readily made of said glass. By virtue of the low liquidus temperature (T.sub.liq), the glass can be drawn into glass tubing which is free of crystals.

Abstract: A quartz glass lamp vessel 1 or 21 is used in many types of lamps. Sometimes it is expedient to absorb a certain portion of the emission spectrum. In accordance with the prior art this is possible by including rare earth metal oxides in the quartz glass.The solubility of rare earth metal oxides in quartz glass is, however, limited.According to the invention, quartz glass is used which contains an alkali metal oxide and optionally, an alkaline earth metal oxide, in addition to a rare earth metal oxide. The alkali metal oxide increases the solubility of the rare earth metal oxide, so that rare earth metal oxides can be used in larger concentrations. This results in glasses which have a higher degree of absorption, from which lamp vessels can be produced.

Abstract: Glass compositions which are suitable for making face-plates of cathode-ray tubes used for displaying television pictures, particularly for displaying color television pictures. A problem in formulating such glasses is to obtain glasses which can be worked satisfactorily and which do not discolor significantly as a result of electron bombardment and X-ray irradiation. The glass compositions consist of the following constituents in the following quantities (expressed in % by weight):______________________________________ SiO.sub.2 57-65 ZrO.sub.2 1-4 Al.sub.2 O.sub.3 0-4 SrO 6-14 Na.sub.2 O 5.5-8.0 PbO 0-1 K.sub.2 O 7.5-10.0 Sb.sub.2 O.sub.3 + As.sub.2 O.sub.3 0-2 MgO 0-4 TiO.sub.2 0.2-2.0 CaO 0-4 CeO.sub.2 0.05-1.0 ______________________________________wherein wt. % Na.sub.2 O/(wt. % Na.sub.2 O+wt. % K.sub.2 O)=0.40-0.47 and wt. % BaO+2 wt. % SrO+2 wt. % ZrO.sub.2 +3 wt. % PbO>32.

Abstract: Doped quartz glass is produced by fusing a mixture of quartz powder with a concentrate. The concentrate consists of quartz powder and the oxides of alkaline earth metals and/or alkali metals (dopants). By adding a small quantity of dopants, a doped quartz glass can be obtained having a viscosity behavior corresponding to that of Vycor glass. Still softer glasses can be obtained by the addition of some more dopants.

Abstract: High-pressure discharge lamp according to the invention have a quartz glass lamp vessel (1) which consists locally of UV-absorbing quartz glass (shaded region 2). During operation of the lamps the normally colder wall parts of the lamp vessel in this region thus assume a higher temperature, as a result of which the efficiency of the lamp is increased while said regions (2) nevertheless remain transparent to visible radiation.