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 value (TDCAC). The invention also describes a gas-discharge lamp and a driver for a gas-discharge lamp.
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 (αv2) 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 (αv1) subtended at the lamp center between the radius and a point on a second long side (15) of the stripe comprises at most 50°. The invention also describes a reflector for a lamp, comprising a reflective interior surface realized to deflect light originating from the lamp outward to give a specific beam profile with a bright/dark cutoff line and a shoulder, and wherein the lamp, in particular a lamp as described above, is positioned horizontally in the reflector, and wherein the reflective interior surface comprises at least one beam-shaping region realized to deflect a portion of the light emitted from the lamp between 7.5° and 15° below a horizontal plane, at a specific region within the beam profile.
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:
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:
A high pressure gas discharge lamp 10 is described with a discharge vessel 20. Electrodes 24 project into a discharge space 22 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 comprises at least halides of Sodium and Scandium with a mass ratio of halides of Sodium and Scandium of 0.9-1.5. The lamp 10 further comprises an outer enclosure 18 provided around the discharge vessel 20, which is sealed and filled with a gas at a pressure below 1 bar. The lamp 10 has an efficiency equal to or greater than 90 lm/W in a steady state operation at an electrical power of 25 W.
Abstract:
A lamp, containing ≦100 ppm Hg, includes a burner chamber having an axis, the axis having a section ≧0.05 mm. The burner chamber has a recess oriented toward a light arc produced in the burning chamber to suppress arc curvature. The lamp has an arc-luminescence profile of luminescence (measured in cd/m2)/mm with an average slope over that section which is ≧|300,000,000| (cd/m2)/mm. Preferably, the profile maximum value is ≧90,000,000 cd/m2. In one embodiment, the arc-making device includes two electrodes disposed for producing the light arc across their two tips, the depth of the recess being sufficiently small so as not to extend between the two tips.
Abstract:
The invention relates to a mercury-free gas discharge lamp suitable in particular for motor vehicles and having an enhanced discharge arc diffuseness, to its use, and to a method of its manufacture. The mercury-free gas discharge lamp according to the invention has an inner vessel and/or outer bulb with a structured arrangement, which structured arrangement is preferably made such that the discharge arc diffuseness of the mercury-free gas discharge lamp with structured arrangement is increased by dD 0.01 mm to 1.5 mm in comparison with the corresponding gas discharge lamp without structured arrangement.
Abstract:
The invention relates to a discharge lamp with a reflector (1) and a burner (2), wherein the reflector (1) comprises at least a reflective contour (3) and a hollow reflector neck (4), the burner (2) is arranged in centered manner in the reflector (1) and the reflector (1) and the lower part (2.1) of the burner (2) are connected firmly together by a mechanical fastening unit and, during assembly, the burner (2) may be guided through the reflector neck (4), starting with its upper part (2.2), and the mechanical fastening unit exhibits such play in the x, y and z directions that the burner (2) can be brought into a defined position relative to the reflector during assembly.
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.