Abstract: An illuminator, particularly for street lighting and industrial applications, comprising a light source including a gas discharge tube, a closed outer vessel for receiving the gas discharge tube, composed from a rear half part and a front half part for forwarding light of the light source, at least the front half part made of light transparent material, light reflecting means covering partly the inner surface of the rear half part of the outer vessel, mechanical fitting elements and electric connecting means, wherein the front half part and the rear half part both are symmetric to at most two symmetry planes and one of the symmetry planes includes the longitudinal axis of the gas discharge tube and constitutes the symmetry plane of the light emitted by the light source. The proposed illuminator require small place and is hardly subject to contamination originated from the environment.

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: A tubular discharge vessel for high pressure sodium vapor lamps has a wall 1 made of light-transmitting material. The tube 1 is hermetically sealed at each end by a respective ceramic stopper 2 through which is passed a respective current lead-in wire 11. An electrode 8 is joined via a shank 10 to the current lead-in wire 11. The interior of the tube is filled with noble gas(es) and metal additive(s), e.g. sodium, mercury and/or cadmium. A cavity 9, preferably of rotationally symmetrical shape is formed in at least one of the stoppers 2. In operation of the discharge tube the cavity 9 is the cold spot. i.e. the internal wall of the lowest temperature. The volume of the cavity 9 is at least equal to the volume of the metal additives in their liquid phase.