Abstract: The invention describes a gas-discharge lamp (1) comprising a vessel (5), which vessel (5) is partially coated with at least one longitudinal stripe (SH, SH?) arranged on the surface of the vessel (5) below a horizontal plane (P) through a longitudinal axis (X) through the centre of the lamp (1) such that, on each side of the lamp, an angle (?H1, ?H2) subtended at the lamp centre by the horizontal plane (P) and an upper edge (16, 17) of the longitudinal stripe (SH, SH?) on that side of the lamp comprises at least 10°, more preferably at least 13°, most preferably at least 15°.

Abstract: A lighting assembly (100) includes an electronic driver circuit (110) and a discharge lamp (10). The discharge lamp (10) is driven with a steady-state average power of 20-30 W. It includes a discharge vessel (20) of a maximum inner dimension ID of less than 3 mm with two electrodes (24). A discharge vessel filling comprises a rare gas and a metal halide composition provided in an amount per volume of the discharge vessel (20) of less than 13.2 ?g/?l. Electrical energy is supplied as an alternating current IL where pulses (150a-150d) are superimposed. The pulses occur in a time interval of 20% of a half-cycle time before or after a polarity change of the alternating current IL. During the pulses the current IL reaches the current value of at least 1.2 times the RMS value of the current IL.

Abstract: A discharge lamp comprises a discharge vessel 20 defining a sealed inner discharge space 22 with two electrodes 24. A filling consists of a rare gas and a metal halide composition and is free of mercury. The discharge vessel 20 comprises outer grooves 36 where the electrodes 24 are embedded, arranged at a groove distance Ra between them. The discharge vessel 20 further comprises an inner diameter ID. In operation of the lamp, an arc discharge is formed between the electrodes and the metal halide composition is partly evaporated. After operation of the lamp, the metal halide composition forms a film on the inner wall of the discharge vessel 20. This film has a surface area AS measured in mm2. The metal halide composition is provided in such an amount within the discharge space 22, that a matching quotient Q, calculated as Q=Ra×ID/AS has a value of 2 or more, such that a high color temperature is achieved.

Abstract: The invention describes a method of driving a gas-discharge lamp (1) according to conditions in a specific region (R) of the lamp (1), which gas-discharge lamp (1) comprises a burner (2) in which a first electrode (4) and a second electrode (5) are arranged on either side of a discharge gap, which lamp (1) is realised such that the position (PCs) of a coldest spot during an AC mode of operation is in the vicinity of the first electrode (4), which method comprises the steps of initially driving the lamp (1) in the AC mode of operation; monitoring an environment variable of the lamp (1), which environment variable is indicative of conditions in a specific region (R) of the lamp (1); switching to a temporary DC mode of operation at a DC power value on the basis of the monitored environment variable, whereby the first electrode (4) is allocated as the anode; and driving the lamp (1) in the DC mode of operation until the monitored environment variable has returned to an intermediate environment variable threshold

Abstract: The invention describes a gas-discharge lamp (1) comprising a vessel (5), which vessel is partially coated with an essentially rectangular stripe (Sv) arranged circumferentially on a surface of the vessel, and wherein a first long side (14) of the stripe is situated close to a base (6) of the lamp, and the width (wv) of the stripe is such that a first angle (?v2) subtended at a lamp center between a radius (r) and a point on the first long side (14) of the stripe comprises at most 55°, and a second angle (?v1) subtended at the lamp center between the radius and a point on a second long side (15) of the stripe comprises at most 50°.

Abstract: A discharge lamp comprises a discharge vessel 20 defining a sealed inner discharge space 22 with two electrodes 24. A filling consists of a rare gas and a metal halide composition and is free of mercury. The discharge vessel 20 comprises outer grooves 36 where the electrodes 24 are embedded, arranged at a groove distance Ra between them. The discharge vessel 20 further comprises an inner diameter ID. In operation of the lamp, an arc discharge is formed between the electrodes and the metal halide composition is partly evaporated. After operation of the lamp, the metal halide composition forms a film on the inner wall of the discharge vessel 20. This film has a surface area AS measured in mm2. The metal halide composition is provided in such an amount within the discharge space 22, that a matching quotient Q, calculated as Q=Ra×ID/AS has a value of 2 or more, such that a high colour temperature is achieved.

Abstract: The invention describes a method of driving a gas-discharge lamp (1) according to conditions in a specific region (R) of the lamp (1), which gas-discharge lamp (1) comprises a burner (2) in which a first electrode (4) and a second electrode (5) are arranged on either side of a discharge gap, which lamp (1) is realised such that the position (PCs) of a coldest spot during an AC mode of operation is in the vicinity of the first electrode (4), which method comprises the steps of initially driving the lamp (1) in the AC mode of operation; monitoring an environment variable of the lamp (1), which environment variable is indicative of conditions in a specific region (R) of the lamp (1); switching to a temporary DC mode of operation at a DC power value on the basis of the monitored environment variable, whereby the first electrode (4) is allocated as the anode; and driving the lamp (1) in the DC mode of op eration until the monitored environment variable has returned to an intermediate environment variable threshold

Abstract: A high pressure gas discharge lamp has electrodes that project into a discharge space surrounded by a discharge wall. The discharge space has a filling of rare gas and metal halides. The metal halide composition comprises halides of sodium and scandium with a mass ratio of halides of Sodium and Scandium of 0.9-1.5. In order to provide a lamp that can be easily manufactured and is well suited for operation at reduced power, the discharge vessel wall is of externally and internally cylindrical shape. The lamp may be manufactured by providing a cylindrical tube of quartz material, heating the tube at two distant portions and forming grooves there, inserting two electrodes into the tube and heating and pinching the tube at both ends to seal the discharge space. Manufacture is carried out without a bulb forming step such that the discharge space remains in externally and internally cylindrical shape.

Abstract: A high-pressure gas discharge lamp has a sealed discharge vessel with an inner discharge space. Two electrodes project into the discharge space. The filling in the discharge space includes metal halides and a rare gas. The filling is free of Hg and Th and includes halides in an amount of 7.1-11.4 ?g/mm3 of the volume of the discharge space. The halides includes at least NaI and ScI3, provided in such amounts that a ratio of the masses of NaI to ScI3 is 1.2-1.6.

Abstract: A high pressure gas discharge lamp includes a discharge vessel with electrodes that project into a discharge space of a volume of 12-20 mm3. The discharge space has a filling of rare gas and a metal halide composition which is free of mercury. The metal halide composition includes at least halides of Sodium and Scandium with a mass ratio of halides of Sodium and Scandium of 0.9-1.5. The lamp further includes an outer enclosure provided around the discharge vessel. The outer enclosure is sealed and filled with a gas at a pressure below 1 bar. The lamp has an efficiency equal to or greater than 90 Im/W in a steady state operation at an electrical power of 25 W.

Abstract: The invention describes a gas-discharge lamp (1) comprising a vessel (5), which vessel is partially coated with an essentially rectangular stripe (Sv) arranged circumferentially on a surface of the vessel, and wherein a first long side (14) of the stripe is situated close to a base (6) of the lamp, and the width (wv) of the stripe is such that a first angle (?v2) subtended at a lamp centre between a radius (r) and a point on the first long side (14) of the stripe comprises at most 55°, and a second angle (?v1) sub-tended at the lamp centre between the radius and a point on a second long side (15) of the stripe comprises at most 50°.

Abstract: The invention describes a gas-discharge lamp (1) comprising a vessel (5), which vessel (5) is partially coated with at least one longitudinal stripe (SH, SH?) arranged on the surface of the vessel (5) below a horizontal plane (P) through a longitudinal axis (X) through the centre of the lamp (1) such that, on each side of the lamp, an angle (?H1, ?H2) subtended at the lamp centre by the horizontal plane (P) and an upper edge (16, 17) of the longitudinal stripe (SH, SH?) on that side of the lamp comprises at least 10°, more preferably at least 13°, most preferably at least 15°.

Abstract: The invention describes a mercury-free high-intensity gas-discharge lamp (1) comprising a discharge vessel (5) enclosing a fill gas in a discharge chamber (2) and comprising a pair of electrodes (3, 4) extending into the discharge chamber (2), for which lamp (1) the fill gas is derived from a salt fill introduced into the discharge chamber (2) prior to sealing, which salt fill is free of scandium and includes a halide composition comprising a sodium halide to a proportion of at least 65 wt % and at most 97.2 wt %,a thallium halide to a proportion of at least 2 wt % and at most 25 wt %, and an indium halide to a proportion of at least 0.5 wt % and at most 25 wt %. Eliminating the highly reactive scandium from the fill gas significantly improves lumen maintenance.

Abstract: A discharge lighting assembly and a method of operating a discharge lamp 10 are described. The discharge lamp 10 includes a discharge vessel 20 with two electrodes 24 for forming an arc discharge. A driver circuit 12 supplies electrical power to the lamp 10 as an alternating lamp current IL and/or an alternating lamp voltage UL with a commutation between half periods of positive and negative values. The driver circuit 12 is controlled to be able to deliver at a predetermined delivery time tD of 10-100 ?s after commutation a voltage level Up which varies in dependence on the lifetime L of the lamp 10.

Abstract: A mercury-free high-pressure gas discharge lamp (HID [high intensity discharge] lamp) is described which is provided for use in automotive technology. To achieve improved lamp characteristics, in particular a substantially equal luminous efficacy in comparison with lamps of the same power and a mercury-free gas filling, as well as a highest possible burning voltage, the discharge vessel (1) is provided in its wall regions (10) which are lowermost in the operational position with a coating (15) which reflects at least a portion of the infrared radiation generated during operation, such that the temperature of the coldest spots, and in particular of the light-generating substances collected there, is raised, with the result that the light-generating substances can enter the gas phase in sufficient quantities also without mercury, and in particular with the use of a metal halide as a voltage-gradient generator.

Abstract: A lighting assembly (100) includes an electronic driver circuit (110) and a discharge lamp (10). The discharge lamp (10) is driven with a steady-state average power of 20-30 W. It includes a discharge vessel (20) of a maximum inner dimension ID of less than 3 mm with two electrodes (24). A discharge vessel filling comprises a rare gas and a metal halide composition provided in an amount per volume of the discharge vessel (20) of less than 13.2 ?g/?l. Electrical energy is supplied as an alternating current IL where pulses (150a-150d) are superimposed. The pulses occur in a time interval of 20% of a half-cycle time before or after a polarity change of the alternating current IL. During the pulses the current IL reaches the current value of at least 1.2 times the RMS value of the current IL.

Abstract: The invention describes a mercury-free high intensity gas-discharge lamp (1) comprising a discharge vessel (5) enclosing a fill gas in a discharge chamber (2) and comprising a pair of electrodes (3, 4) extending into the discharge chamber (2), for which lamp (1) the fill gas in the discharge chamber (2) is free of zinc iodide, and the fill gas includes a halide composition comprising sodium iodide and scandium iodide to a combined proportion of at least 30 wt % and at most 95 wt %, and thulium iodide, to a proportion of at least 5 wt % and at most 70 wt %.

Abstract: The invention describes a mercury-free high-intensity gas-discharge lamp (1) comprising a discharge vessel (5) enclosing a filling in a discharge chamber (2) and comprising a pair of electrodes (3, 3?, 4, 4?) extending into the discharge chamber (2), for which lamp (1) the electrodes (3, 3?, 4, 4?) are free of thorium, and the filling includes a halide composition comprising at least 6 wt % thorium iodide.

Abstract: In order to achieve a discharge lamp suited to operate under reduced nominal power of e.g. 20-30 W, a lamp is proposed with two electrodes (24) arranged at a distance in a discharge vessel (20, 120) for generating an arc discharge. The discharge vessel (20, 120) has a filling with a substantially free of mercury and comprises a metal halide and a rare gas. The lamp (10, 110) further comprises an outer bulb (18) arranged around the discharge vessel at a distance (d2). The outer bulb (18) is sealed and has a gas filling of a thermal conductivity (?). The inner diameter (d1) of the discharge vessel is preferably in a range from 2-2.7 mm. The wall thickness (w1) is in a range from 1.4-2 mm. A heat transition coefficient (?/d2) is calculated as thermal conductivity (?) at 800° C. of the outer bulb filling divided by the distance (d2). The so-defined heat 10 transition coefficient is below 150 W/(m2K).

Abstract: In order to achieve a discharge lamp suited to operate under reduced nominal power of e.g. 20-30 W, a lamp is proposed with two electrodes (24) arranged at a distance in a discharge vessel (20, 120) for generating an arc discharge. The discharge vessel (20,120) has a filling with a substantially free of mercury and comprises a metal halide and a rare gas. The lamp (10, 110) further comprises an outer bulb (18) arranged around the discharge vessel at a distance (d2). The outer bulb (18) is sealed and has a gas filling of a thermal conductivity (?). The inner diameter (d1) of the discharge vessel is preferably in a range from 2-2.7 mm. The wall thickness (w1) is in a range from 1.4-2 mm. A heat transition coefficient (?/d2) is calculated as thermal conductivity (?) at 800° C. of the outer bulb filling divided by the distance (d2). The so-defined heat 10 transition coefficient is below 150 W/(m2K).