Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation.

Abstract: An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity and an envelope bottom, an electromagnetic coupler positioned within the reentrant cavity, and a thermal shield positioned in proximity to the envelope bottom and configured to increase the temperature of the envelope bottom. By increasing the temperature of the envelope bottom, a cold spot is prevented. As a result, light output at low temperatures is comparable to light output at room temperature.

Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio with D exceeding a minimum value. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation for a lamp dissipation sufficient to have the chamber wall loading exceed a minimum value or so as to maintain chamber luminosity above a minimum value for a selected operational duration.

Abstract: An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity and an envelope bottom, an electromagnetic coupler positioned within the reentrant cavity, and a thermal shield positioned in proximity to the envelope bottom and configured to increase the temperature of the envelope bottom. By increasing the temperature of the envelope bottom, a cold spot is prevented. As a result, light output at low temperatures is comparable to light output at room temperature.

Abstract: A lighting system includes a high intensity discharge metal halide lamp having an arc discharge chamber with electrodes at each end and containing a fill of mercury, rare gas and metal halides, and a ballast circuit configured to supply pulsed electrical power to the lamp. The ballast circuit includes a controller configured to adjust the pulsed lamp power between a first relatively high power level at a relatively high duty cycle and a second relatively low power level at a relatively low duty cycle. The controller may be configured to adjust the pulsed lamp power between 90% duty cycle at rated lamp power and 10% duty cycle at 30% of the rated lamp power. The duty cycle of the pulsed lamp power may be controlled to maintain a substantially constant correlated color temperature (CCT) as the power level is adjusted.

Abstract: An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity; an electromagnetic coupler positioned within the reentrant cavity; and a cold spot structure configured for low temperature, low duty cycle operation and for room temperature, 100% duty cycle operation. In some embodiments, the cold spot structure includes a dimple in the lamp envelope, the dimple having a thinned sidewall. In further embodiments, a shield is positioned near the dimple to control cold spot temperature. In additional embodiments, the cold spot structure includes a heat sink attached to the exhaust tube of the lamp envelope and thermally isolated from the lamp base.

Abstract: An electrodeless lamp includes a bulbous lamp envelope enclosing an inert gas and a vaporizable metal fill, the lamp envelope having a reentrant cavity, a magnetic core positioned within the reentrant cavity, an induction coil disposed on the magnetic core, a cooling structure disposed inside the magnetic core, and a spacer structure between the magnetic core and an inside wall of the reentrant cavity. The spacer structure defines a thermally insulating gap between the magnetic core and the inside wall of the reentrant cavity to control coil/core temperature.

Abstract: Methods and apparatus are provided for operating very high pressure short arc mercury discharge lamps primarily used for projection applications. The method includes controlling an alternating lamp current supplied to the lamp at a constant RMS value. In some embodiments, the lamp current is adjusted to a new constant RMS value to maintain lamp power between an upper power limit and a lower power limit. In other embodiments, lamp cooling is adjusted to maintain a wall temperature of the arc tube below a softening temperature.

Abstract: An electrodeless fluorescent lamp is configured such that the lamp operates at frequencies less than 500 kHz both in and out of a fixture with little change in performance. The lamp employs relatively high rare gas pressure, relatively small reentrant cavity diameter and a relatively short magnetic core to achieve good performance in the fixture.

Abstract: An arc discharge metal halide lamp having a discharge chamber with visible light permeable walls bounding a discharge region through which walls a pair of electrode assemblies are supported with interior ends thereof positioned in the discharge region spaced apart from one another. These electrode assemblies each also extend through a corresponding capillary tube affixed to the walls to have exterior ends thereof positioned outside the arc discharge chamber. At least one of these electrode assemblies comprises an electrode discharge structure with a discharge region shaft extending into the capillary tube corresponding thereto. A discharge region shaft extends outwardly in that corresponding capillary tube to be in direct contact with an interconnection shaft extending outside of that corresponding capillary tube to provide an exterior end of this electrode assembly, and which is in direct contact with a sealing cap over the end of the tube.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable ceramic walls of a selected shape about a discharge region of a selected volume. A pair of electrodes are supported in the discharge region separated from one another by a separation length. The separation length is in a ratio to the effective inner diameter that is greater than four. Ionizable materials are provided in the discharge region comprising a quantity of mercury in a ratio to the discharge region volume that is less than 4 mg/cm3, a noble gas, praseodymium halide, and sodium halide.

Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio with D exceeding a minimum value. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation for a lamp dissipation sufficient to have the chamber wall loading exceed a minimum value or so as to maintain chamber luminosity above a minimum value for a selected operational duration.

Abstract: An arc discharge metal halide lamp having a discharge chamber having visible light permeable walls bounding a discharge region supported electrodes in a discharge region spaced apart by a distance Le with an average interior diameter equal to D so they have a selected ratio. Ionizable materials are provided in this chamber involving a noble gas, one or more halides, and mercury in an amount sufficiently small so as to result in a relatively low maximum voltage drop between the electrodes during lamp operation.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures comprising a discharge chamber having light permeable walls of a selected shape including therein a pair of end region wall portions through each of which a corresponding one of a pair of electrodes are supported separated from one another by a separation length. The ratio of the separation length to the effective operation inner diameter of the chamber is greater than two. The lengths of the wall sides between the end wall portions is greater than the effective operation inner diameter. The end wall portions have inner surfaces of constant or smaller varying radii of curvature and they are separated from the interior ends of the electrodes by more than one millimeter. The discharge chamber can be constructed of polycrystalline alumina and contain metal halides.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable ceramic walls about a discharge region. A pair of electrodes are supported in the discharge region spaced apart from one another. Ionizable materials are provided in the discharge region comprising mercury, a noble gas, and at least two metal halides including a magnesium halide and a sodium halide, a rare earth clement, and thallium iodide in a molar quantity which is between 0.7 and 5% of that total molar quantity of all halides present in the discharge chamber.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable ceramic walls about a discharge region. A pair of electrodes are supported in the discharge region spaced apart from one another. Ionizable materials are provided in the discharge region comprising mercury, a noble gas, and at least two metal halides including a magnesium halide and a sodium halide, a rare earth element, and thallium iodide in a molar quantity which is between 0.7 and 5% of that total molar quantity of all halides present in the discharge chamber.

Abstract: An electrodeless lamp includes an envelope (1) containing a fill of discharge gas, a magnetic core t(7), an induction coil (6) wound around the magnetic core (7), a driver circuit for supplying an electric current to the induction coil (6) to operate the electrodeless lamp, a socket (10) for receiving electrical power supplied to the electrodeless lamp, and a heat conduction means (8,9) thermally coupled to the magnetic core (7) for conducting heat generated in the magnetic core (7) to the ambient atmosphere to dissipate heat therein, or coupled to the socket (10) for conducting heat generated in the magnetic core (7) to the socket to dissipate heat therethrough.

Abstract: A [thallium free] high pressure ceramic metal halide lamp having superior dimming characteristics with a fill composition including MgI2 and/or MgBr2.

Abstract: A metal halide lamp having excess amount of red radiation, well beyond a tungsten halogen lamp of the same color temperature. The deep saturated red being accomplished with reasonable efficacy utilizing a mixture of sodium and rare earth halides, additional broadening of the Na “D” lines and filtering out the yellow radiation at about 590 nm. The red radiation is comparable to the commercially available white high pressure sodium lamp red radiation.

Abstract: An arc discharge metal halide lamp for use in selected lighting fixtures having a discharge chamber with light permeable ceramic walls of a selected shape about a discharge region of a selected volume. A pair of electrodes are supported in the discharge region separated from one another by a separation length. The separation length is in a ratio to the effective inner diameter that is greater than four. Ionizable materials are provided in the discharge region comprising a quantity of mercury in a ratio to the discharge region volume that is less than 4 mg/cm3, a noble gas, praseodymium halide, and sodium halide.