Abstract: The invention relates to a high pressure sodium vapor lamp having improved color reproduction index, which has a discharge vessel (1) placed in an outer envelope (10) and at least a pair of electrodes (4,5) and a filling comprising of at least one additive material and a fill gas, as well as a pair of current conductors (6,7) for supplying current for the electrodes (4,5). The essence of the invention resides in that especially in the case of high pressure sodium vapor lamps of low output for the increasing of the color reproduction index filaments (2,3) are arranged at the ends and outside of the discharge vessel (1) and which during the entire operation of the discharge vessel (1) are connected in series therewith.

Abstract: The invention concerns a headlamp, the envelope of which is constituted internally by at least one concave reflecting surface, preferably by paraboloid-shape and spherical surfaces, and having a light-emitting element in, or near, the focus of the main reflecting surface and mounted on the current conducting support, and the envelope being shut-up by a transparent cover plate. The essence of the invention consists of having a convex mirror located between the light-emitting element and the cover plate, with its reflecting surface facing the light-emitting element and the concave reflecting surfaces. The surface of the convex mirror is preferably of the shape of a hyperboloid of rotation.

Abstract: The invention relates to a headlamp, the envelope of which is constituted internally by concave reflecting surfaces but at least by one concave reflecting surface having the shape of a paraboloid of rotation, further, in the focus of said paraboloid-shape reflecting surface a light-emitting element is accommodated with its center line being perpendicular to the axis of the reflecting surface, further, having said envelope shut up with a transparent cover plate, the surface of which is uniformly roughened, and/or on said surface uniformly distributed, geometrically regular beam-forming optical elememts are provided. Essential feature of the invention consists of having over the cover plate (1) also irregularly-shaped oblong beam-forming optical elements, the longitudinal axes of which are parallel with the center line (10) of the light-emitting element (2). Said oblong beam-forming optical elements are expediently cylindrical lenses (5, 6, 7, 8) or prisms.

Abstract: Electrical current supply terminal, especially for discharge tubes of light sources having a high pressure gas discharge.The invention is concerned with an electrical feed through, especially for discharge tubes of light sources having high pressure gas discharge, which current supply terminal is passed through a ceramic material, preferably from aluminum oxide and with a binding material is hermetically binded thereto, the heat expansion coefficient of which is appropriately selected and which is preferably vitreous enamel.In order to eliminate the difficulties resulting from the different heat expansion coefficient of ceramics, binding material and the metal material, the feed through is formed from a bundle of metallic threads.The bundle comprises preferably strands or braids and as material preferably molybdenum or tungsten is used.