Patent-treuhand-gesellschaft F. Elektrische Gluehlampen Mbh

Patent Treuhand Gesellschaft Fur Elektrische Gluhlampen Mbh

Ulrich Henger

Achim Gosslar

Juergen Heider

Karl-Heinz Gleixner

Hartmuth Bastian

The discharge or arc tube chamber of a low-power high-pressure discharge lamp is, in one single step, sealed and shaped by mold or form-blowing by using pinch or press jaws (30, 31) which have concave hollows (34) formed therein to clearly define the shape of the discharge vessel, and hence of the discharge or arc tube chamber, to permit reproducible results with little variation between individual lamps to be made in a single manufacturing step. Additionally, an inclined ramp-like surface can be formed at the narrow sides (14) of the pinch seal extending towards the walls (11) of the discharge chamber (3) to thereby eliminate pockets beneath the electrodes. Preferably, the electrode shafts diverge with respect to the optical axis (A) of the lamp to increase the electrode spacing, and thus permit operation at a lower operating pressure, with respect to prior art lamps.

Single-ended low-power discharge lamp, and method of its manufacture

To simply and reliably retain a heat retention tube or sleeve (10) within envelope (1) and surrounding the arc tube or discharge vessel (4) of the lamp, end regions of the heat retention or conservation tube are pinched around current supply leads (7) which pass through the pinch or press region (11). To prevent dislocation of the tube or sleeve (10), axially as well as rotationally with respect to the arc tube, the current supply leads are deformed in the region of the pinch or press (11), for example by being flattened or deflected in a bend or V-shape from a straight wire. An exhaust tube (12) can be passed through the pinch (11) if the pinch extends across the entire diameter of the heat retention tube; otherwise, the pinch need only extend over a portion thereof, thus providing for pneumatic communication between the interior of the heat retention tube and the envelope (1).

Single-based high-pressure discharge lamp with a heat retention structure

To facilitate manufacture and assembly of a high-pressure discharge lamp ing an inner discharge vessel (4) within an outer bulb (1), and which is protected against explosion or bursting of the discharge vessel by a protective sleeve or body (8), typically formed of two sleeves or tubes (8a, 8b) of quartz glass or hard glass, the two glass tubes surround the discharge vessel (4) over its entire coaxial length and, when coated with an infrared (IR) reflective coating and an ultraviolet (UV) radiation coating, additionally function as a heat retention or heat damming element and a UV radiation protective element. Two ceramic insulating centering and holding elements are carried by a lamp holder structure (9), engaging the open ends of the glass tubes (8a, 8a). The ceramic elements are formed with steps (20a, 20b, 20c) or grooves (520a, 520b) to position the glass tubes spaced from each other and concentric with respect to the discharge vessel. Openings (13, 513) in the ceramic elements permit passage of the connecting leads (6) to the discharge vessel (4). The ceramic elements can be cruciform, star or spider-shaped, or ring-shaped with an apertured web or a transverse rib (19), to provide for pneumatic communication to the interior of the protective body (8) and easy evacuation of the outer bulb (1).

Explosion-protected high-pressure discharge lamp

The high-pressure lamp has a fill including a metal halide of two groups, which the first group is a first rare earth halide of dysprosium, thulium and optionally holmium, and a second group of rare earth halide, namely cerium, neodymium, praseodymium, lanthanum; and an alkali metal halide, such as sodium halide and/or cesium halide, preferably iodide or bromide of sodium and/or cesium. The lamp has a high proportion of light radiation in the red range of the color spectrum to provide substantially improved color rendering indices, particularly in the Ra.sub.8 region, thereby providing better color balance, without loss of lifetime.

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Wipperfurth, Germany

Ulrich Henger