Abstract: The packaging carton of the packed electric lamp has an incision line through diagonally opposed edges in respective side walls adjoining these edges. Boundary lines extend in each of the two side walls from said incision line to a point P of the edge, which point lies closer to the first end, so as to define together with the incision line a region of said walls which is flipped over as a folded portion into the carton, thus narrowing the carton. The lamp may be readily machine packed into the carton, starting from the back of the carton, and displays essential distinguishing marks of its bulb while the packaging remains closed.

Abstract: The electric reflector lamp has a light source in an envelope with a seal. The seal has a projection against which a plate rests, the plate having a side which faces the light source. The seal is secured in the neck of a reflector body by means of cement which is present at a side of the plate which faces away from the light source. Thereby, an open passage to the beam-shaping portion of the reflector body exists allowing volatile substances released by the cement to escape when the reflector body is closed by means of a cover.

Abstract: A metal halide lamp includes a discharge vessel with a ceramic wall and a filling which comprises besides mercury and a halogen also Na, Tl and one or several of the elements from the group formed by Sc, Y and lanthanides. The filling also contains Mg to improve lumen maintenance.

Abstract: The electric lamp (1) has a lamp vessel (2), wherein an electric element (3) is accommodated. This element is connected to current conductors (4). Molybdenum end portions (5) of the current conductors extend outside the lamp vessel and have a skin of molybdenum nitride as a protection against oxidation.

Abstract: A lighting unit according to the invention comprises an electrodeless low-pressure discharge lamp and a high-frequency supply. The electrodeless low-pressure discharge lamp is provided with a discharge vessel which is closed in a gastight manner, comprises an ionizable filling, and has an enveloping portion and a recessed portion surrounded by the enveloping portion, which enveloping and recessed portions of the discharge vessel each support a luminescent layer. The electrodeless low-pressure discharge lamp is in addition provided with a coil which is arranged in the recessed portion of the discharge vessel and which is electrically connected to the supply. The conversion efficiency of the luminescent layer on the recessed portion is relatively high compared with that of the luminescent layer on the enveloping portion. This measure renders possible a lower temperature of the core.

Abstract: An electrodeless low-pressure discharge lamp (10) according to the invention is provided with a radiation-transmitting discharge vessel (11) which encloses a discharge space (14) containing an ionizable filling in a gastight manner. The lamp (10) is in addition provided with a first and a second winding (20, 23) for conducting a high-frequency current during operation. The first winding (20) extends along a longitudinal axis (29) in a cavity (28) surrounded by the discharge vessel (11). The second winding (23) is arranged along the longitudinal axis (29) in the extended direction of the first winding (20) outside the cavity (18) surrounded by the discharge vessel (11). During operation, the currents in the first and second windings (20, 23) have the same tangential direction relative to the longitudinal axis (29). The lamp causes comparatively little magnetic interference, while it is avoided that the second winding (23) hampers lamp ignition or causes an unstable lamp operation.

Abstract: The packed electric lamp has a back wall with a first sleeve comprising a base and a first fixation wall with an opening, and a second sleeve comprising a top and a second fixation wall with an opening. Side walls are connected to the back wall and fastened to the first and second sleeves by means of folded tongues. The lamp is held fixed in the with respective end portions. The packing keeps the lamp securely fixed in place, while nevertheless a substantial portion of the lamp is visible. The packing may be readily shaped from its blank and simultaneously made to hold the lamp.

Abstract: The invention relates to a measuring circuit for detecting the amount of deposited electrode material on the wall of a lamp vessel of a discharge lamp by measuring the power of infrared radiation within a specific wavelength range, comprising a detector for generating an electrical signal constituting a measure for the power of the infrared light in said specific wave length range. According to the invention the measuring is done in a time lapse starting after a predetermined time interval following the extinguishing of the discharge lamp. An increased accuracy of the measurement is thereby realized.

Abstract: The electric lamp has a quartz glass lamp vessel in which a light source is accommodated. The lamp vessel is covered by an interference film which has layers of alternatingly silica and a material of relatively high refractive index. A silica containing adhesive layer is in between the lamp vessel and the film. The adhesive layer has a content of boron oxide and/or phosphorus oxide.

Abstract: The capped high-pressure discharge lamp has a discharge vessel having opposite neck-shaped portions. A tubular glass sleeve envelopes the discharge vessel and has constrictions coupling the sleeve to a respective neck-shaped portion. The sleeve has an end-portion adjacent a constriction at the side thereof which is remote from the other constriction, in which end portion a pinch is present. A clamping member having lugs which hold the pinch is secured to a mounting member which is fixed to a cap. The pinch provides for a mechanically strong portion to secure the discharge vessel to the cap. The construction is able to withstand heavy shocks which may occur during transport.

Abstract: A low-pressure mercury discharge lamp with a lamp vessel having a first lamp vessel portion (La1) with a first electrode (E11) and a first luminescent layer which radiates white light of a first color temperature during lamp operation and a second lamp vessel portion (La2) with a second electrode (E12) and with a second luminescent layer which radiates white light of a second colour temperature different from the first during lamp operation. The first lamp vessel portion and the second lamp vessel portion are interconnected by a connection which allows a filling of mercury and a rare gas in both portions to pass and together enclose a discharge space. The discharge space contains only one further electrode (E13) for both the first and second lamp vessel portions.

Abstract: The low-pressure discharge lamp is discolsed having a lamp vessel into which hollow cylindrical electrodes enter, between which a discharge path extends. At least one of the electrodes has a tube at a distance from an end thereof, the tube extending in the discharge path. The tube is connected to the electrode by electrically conductive means and is coated with electron emissive material. The surface area of the material of the means in cross-section is at most 25% of the surface area of the material of the electrode in cross-section.

Abstract: A method of selecting low-pressure mercury discharge lamps comprising a luminescent layer, the luminescent layer being excited and the low-pressure mercury discharge lamps being selected in dependence on the emission spectrum of the visible light emitted by the luminescent layer. The luminescent layer is excited by a light source arranged outside the low-pressure mercury discharge lamp and which generates ultraviolet radiation having a wavelength above 300 nm. This makes it possible to use the presence of a blue-luminescent substance in the luminescent layer as a selection criterion for both leaky and intact low-pressure mercury discharge lamps.

Abstract: The electric reflector lamp has a reflector body with a light-beam shaping surface which comprises a body of revolution of a branch of a parabola which has been tilted towards the optical axis of the light-beam shaping surface. The light-beam shaping surface has superimposed plane axial lanes of which the number in a first zone remote from the light emission window is half that in a second zone adjacent said window. The axial lanes give the light-beam shaping surface cross-sections which are regular polygons. A light source is positioned on the optical axis, while the focus is inside this light source. The lamp has a universal burning position, a good mixing of the generated light, and a comparatively high luminous flux in the beam.

Abstract: A low-pressure mercury vapor discharge lamp with a tubular discharge vessel (1) with an internal diameter D. The discharge vessel (1) encloses a discharge space (3), which comprises mercury and a rare gas, in a gastight manner. Electrodes (5A, 5B) are arranged in end portions (4A, 4B) of this discharge space. The discharge vessel (1) has a luminescent layer (10) which supports a protective layer (11) comprising a metal oxide at an inner surface (9). In the lamp according to the invention, at least 75% by weight of the metal oxide is present in total in the end portions (4A, 4B), said end portions (4A, 4B) each extending up to a distance beyond the electrodes (5A, 5B) which is three times the internal diameter of the discharge vessel (1). The lamp has a comparatively low luminous decrement and can be manufactured comparatively efficiently.

Abstract: A high pressure gas discharge lamp includes first and second discharge devices electrically connected in series within an outer envelope. The discharge devices each include a discharge vessel enclosing a discharge space with an ionizable fill and first and second discharge electrode assemblies. The first discharge electrode assemblies of the discharge devices are connected so as to receive a starting pulse and lamp operating voltage. Each discharge vessel includes a first wall portion spaced from the first discharge electrode assembly and defining an ionizable gap therebetween. A conductive element bridges the discharge devices at the first wall portions and capacitively couples the first discharge electrode assemblies to induce ionization in one of the discharge devices in the ionizable gap between the first wall portion and first discharge electrode assembly.

Abstract: A low-pressure discharge lamp according to the invention is provided with a radiation-transmitting discharge vessel which encloses a discharge space containing an ionizable filling in a gastight manner, and electrodes arranged in the discharge space between which a discharge path extends. At least one of the electrodes is a sintered mixture of metal and ceramic material, the proportional quantity of metal in the mixture being small compared with the proportional quantity of ceramic material. The sintered mixture includes smaller ceramic particles with a modal diameter D1 and larger ceramic particles with a modal diameter D2, the ratio D2/D1 being at least 3, while the proportional volume of the smaller ceramic particles is small compared with that of the larger ceramic particles. In the lamp according to the invention, the electrodes have a comparatively high resistance to temperature variations in spite of the small proportional volume of metal particles.

Abstract: The capped electric lamp has a glass lamp vessel (1) having first and second neck-shaped portions (2,3). An outer glass envelope (8) has a narrowed portion (9) where it is coupled to the first neck-shaped portion (2). A metal sleeve (10) has a clamping zone (11) which clampingly holds the outer envelope (8), and a welding zone (12) to which tongues (21) of a fixation member (20) which is fixed in a lamp cap (30) are welded. The metal sleeve (10) becomes narrower from the clamping zone (11) towards the first neck-shaped portion (2) up to the welding zone (12).

Abstract: An illumination unit according to the invention comprises an electrodeless low-pressure discharge lamp 10. The illumination unit is provided with a lamp vessel 20 which encloses a discharge space 21 which contains an ionizable filling. The illumination unit is in addition provided with a holder 60 for the lamp vessel 20, with a coil 30 for generating a high-frequency magnetic field so as to maintain an electric discharge in the discharge space 21, and with a high-frequency supply 50 for the coil. The illumination unit is further provided with ignition aids 40 for promoting the initiation of the discharge.

Abstract: The capped high-pressure discharge lamp suitable for use in a vehicle headlight has a discharge vessel which is surrounded by an outer envelope. Current conductors extend from a respective electrode to a respective contact at a cap in which a first neck-shaped portion of the discharge vessel is secured. A return portion of one current conductor extends along an outside surface of the outer envelope. The outer envelope has a light-absorbing coating in a region near the first neck-shaped portion, at a side which is remote from the return portion. The outer envelope may have band-shaped coatings at either side, aside from the discharge path between the electrodes, at its side which faces the return portion. Stray light in the beam formed by the reflector and the lens of a head-light in which the lamp is used, is obviated. The bands provide for a rectilinear light/dark transition in said beam.