Abstract: A method of operating an arc discharge lamp and a lamp in which a light transmissive envelope encloses electrode tips, a salt and a fill that includes iodine, and in which after turning the lamp off, a first part of the light transmissive envelope is locally cooled relative to other parts of the light transmissive envelope to provide a condensation site for the iodine that is spaced from the electrode tips, the first part of the light transmissive envelope being where a salt reservoir forms and where the salt is cooled by the local cooling. The local cooling may be provided by an indentation in an outer sleeve around the light transmissive envelope, where the indentation contacts the first part to provide a heat sink.

Abstract: An arc discharge light source (10) for automotive headlight applications comprises an arc tube (12) having a hollow body (14) arrayed along a longitudinal axis (16) and provided with first and second ends (18, 20). The first and second ends have, respectively, first and second jointure areas (22, 24) with the hollow body (14). Electrodes (26, 28) are sealed respectively in each of the first and second ends (18, 20). An arc generating and sustaining medium is contained within the hollow body. a low-voltage-pulse starting aid (30) is associated with the arc tube and comprises an electrically conductive member (32) having an intermediate portion (34) and proximal and distal ends (36, 38). The intermediate portion (34) extends the length of the hollow body (14) and the proximal and distal ends (36, 38) each terminating in a loop (40, 42) comprised of a single turn of electrically conductive material.

Abstract: Operation of an HID lamp may be improved by forming a glow generating recess on an exterior side the electrode. The lamp may be of standard construction with a light transmissive lamp envelope having a wall defining an enclosed volume. At least one electrode assembly is extended in a sealed fashion from the exterior of the lamp through the lamp envelope wall to be exposed at an inner end of the electrode assembly to the enclosed volume. A metal halide lamp fill is enclosed with an inert fill gas. The inner end of the electrode is formed with a recess having a least spanning dimension S and a recess depth of D where S is greater the electron ionization mean free path but less than twice the cathode fall plus negative glow distances, throughout the glow discharge phase of starting, for the chosen fill gas composition and pressure (cold).

Abstract: A starting aid for a metal halide lamp uses iodine and an inert gas instead of mercury so that the entire metal halide lamp may be mercury-free. The starting aid is a UV enhancer that includes a UV-transmissive capsule with a cavity in which iodine and an inert gas are sealed, wherein the iodine emits UV radiation when excited to reduce a starting voltage of the lamp.

Abstract: A starting aid for a metal halide lamp uses iodine and an inert gas instead of mercury so that the entire metal halide lamp may be mercury-free. The starting aid is a UV enhancer that includes a UV-transmissive capsule with a cavity in which iodine and an inert gas are sealed, wherein the iodine emits UV radiation when excited to reduce a starting voltage of the lamp.

Abstract: An electrodeless high intensity discharge lamp with a lamp fill material including gallium iodide has been found to be more efficient in generating light in general, and more efficient in generating blue light. The very small size of the lamp, in combination with the high intensity in a relatively narrow blue spectral range make the lamp particularly useful in supplying blue light to a fiber optic. The relative efficiency of the lamp increases its value. In combination, the lamp provides a useful, efficient source of blue light as an input source for optical fiber, and other systems for medical and other processes using blue light as a process element.

Abstract: An electrodeless high intensity discharge lamp includes an electrodeless lamp capsule having an enclosed volume containing a mixture of starting gas and chemical dopant material excitable by high frequency power to a state of luminous emission, an applicator for coupling high frequency power to the lamp capsule, a gas nozzle directed toward the lamp capsule and a gas controller coupled to the gas nozzle. The gas controller receives gas from a gas source and supplies a gas puff of limited duration to the lamp capsule through the gas nozzle in response to termination of the state of luminous emission. The lamp capsule is rapidly cooled by the gas puff to a temperature required for restart.

Abstract: A light source, particularly suited for surgical and other medical illumination applications, includes an electrodeless lamp assembly, a reflector having the electrodeless lamp assembly mounted therein and high frequency power source for supplying high frequency power to the electrodeless lamp assembly. The electrodeless lamp assembly includes an electrodeless high intensity discharge lamp capsule including a light transmissive discharge envelope enclosing a discharge volume containing a mixture of starting gas and chemical dopant material excitable by high frequency power to a state of luminous emission. The luminous emission has a color rendering index greater than 85 and preferably has a color rendering index greater than 90. The luminous emission preferably has low energy in the spectral range of 800 to 1000 nanometers relative to energy in the visible spectral range.

Abstract: An apparatus and method for operating an arc discharge lamp which can be hot restarted is described. The method involves providing low microwave power after the lamp ballast is disconnected from the lamp. The microwave power is modulated such that conductivity is maintained within the lamp as the lamp cools. Restarting the lamp is accomplished by reconnecting the ballast at any time. In one embodiment, the apparatus of the invention includes an arc discharge lamp and ballast coupled together with a switch to turn the lamp on and off. A microwave power supply is connected in parallel with the ballast and is coupled to the lamp when the ballast is shut off. The invention allows for hot restart of the arc lamp without requiring a high voltage pulse.

Abstract: In one aspect of the present invention a capacitor is placed in series with the ballast and the lamp. The capacitor lowers the impedance during lamp starting and is shorted out when final arc conditions of the lamp are reached. Method and device for improvement of lumen maintenance of high intensity discharge lamps through minimizing the wall blackening during lamp starting is disclosed. Reducing the electrode material sputtering during the thermionic arc phase of the lamp starting process was achieved by decreasing the cathode fall voltage. The cathode fall voltage in these lamps was decreased by increasing the current flowing through during the starting phase. The increase of starting current was achieved by increasing the open circuit voltage or by decreasing ballast impedance.

Abstract: In one aspect of the present invention a capacitor is placed in series with the ballast and the lamp. The capacitor lowers the impedance during lamp starting and is shorted out when final arc conditions of the lamp are reached. Method and device for improvement of lumen maintenance of high intensity discharge lamps through minimizing the wall blackening during lamp starting is disclosed. Reducing the electrode material sputtering during the thermionic arc phase of the lamp starting process was achieved by decreasing the cathode fall voltage. The cathode fall voltage in these lamps was decreased by increasing the current flowing through during the starting phase. The increase of starting current was achieved by increasing the open circuit voltage or by decreasing ballast impedance.

Abstract: The present disclosure describes a method for determining the condensate location within an HID lamp. The method involves monitoring current and voltage waveforms during the glow phase of lamp starting. If the voltage drop during the glow phase is low with a corresponding high current, then the volatile component of the lamp fill has condensed on the electrodes during the previous cool down period. If the voltage drop is high and current is low then most of the condensate has localized on the arc tube wall. An automated detection apparatus is used to carry out the measurements to determine condensate location.

Abstract: A beam mode discharge lamp typically has a shortcoming in that emitted light is reduced due to the deposition of cathode material on the phosphor surface. Such deposition can be reduced through the addition of a conductive mesh about the filaments to entrap cathode material and inhibit same from attacking the phosphor material.

Abstract: An improvement in dual beam mode fluorescent lamps in which a capacitive ballast is provided integral with the lamp structure in the form of a cylindrical laminate of metal and insulator coaxial to the lamp's major axis.

Abstract: A fluorescent lamp is described in which spontaneous excimer UV emission in an inner tube results from reacting an inert gas molecule with a halide molecule in the excited state. The UV emission travels through the inner tube envelope to an outer tube and is absorbed by a fluorescent material, i.e., phosphor, to produce visible light which passes through the outer tube envelope. The halide may be supplied by metal halide pellets or liquid droplets, which when heated by an initial discharge through an inert gas, produces metal halide vapors which dissociate and combine with the inert gas (Xe, Ar, Ne, Kr) in the excited state and result in UV excimer emission.

Abstract: A beam mode lamp has two discharge electrodes which alternately function as anode and cathode. One or more modifying electrodes are located between the discharge electrodes. Each modifying electrode is kept equal to or negative with respect to the cathode, raising the operating voltage of the lamp from a normal 20 volts to line voltage.

Abstract: The lamp shown herein is a beam mode fluorescent lamp for general lighting applications. The lamp comprises a light transmitting envelope, having a phosphor coating on its inner surface, enclosing a thermionic cathode for emitting electrons, a pair of anodes for accelerating the electrons and forming electron beams, and a fill material, such as mercury, which emits ultraviolet radiation upon excitation. The two anode configuration provides an extended region of electron beam excitation. In addition, a separate cathode heater filament is not required due to the anode configuration. As a result this lamp is operated with a single power source and only two conductors connecting the power source to the electrodes. This invention further provides a high degree of self-stabilization of discharge current by means of the twin parallel anode configuration.

Abstract: The lamp shown herein is a beam mode fluorescent lamp for general lighting applications. The lamp comprises a light transmitting envelope, having a phosphor coating in its inner surface, the envelope encloses a thermionic cathode having a number of segments for emitting electrons, a plurality of anodes for accelerating the electrons and forming a corresponding number of electron beams simultaneously in two directions, and a fill material, such as mercury, which emits ultraviolet radiation upon excitation. The multi-electrode array configuration provides an extended region of electron beam excitation and thereby more visible light. A single power source and pair of connecting conductors provide both cathode heating current and electrode potential difference functions. In addition, this configuration provides for a greater and more complete discharge of the volume within the envelope than single electrode elements.

Abstract: The lamp shown herein is a beam mode fluorescent lamp for general lighting applications. The lamp comprises a light transmitting envelope, having a phosphor coating on its inner surface, enclosing a single electrode including a thermionic cathode for emitting electrons and an integral anode for accelerating the electrons and forming an electron beam, and a fill material, such as mercury, which emits ultraviolet radiation upon excitation. The electrode configuration provides for use of a single power source and minimal number of power leads. In addition, a separate cathode heater filament is not required.

Abstract: The lamp shown herein is a beam mode fluorescent lamp for general lighting applications. The lamp comprises a light transmitting envelope, having a phosphor coating on its inner surface, the envelope encloses a thermionic cathode having a number of segments for emitting electrons, a plurality of anodes for accelerating the electrons and forming a corresponding number of electron beams, and a fill material, such as mercury, which emits ultraviolet radiation upon excitation. The multi-electrode array configuration provides an extended region of electron beam excitation and thereby more visible light. A single power source and pair of connecting conductors perform both cathode heating current and electrode potential difference functions. In addition, this configuration provides for a greater and more complete discharge of the volume within the envelope than single electrode elements. The present invention permits a higher operating voltage, lower power density and a lower operating temperature for the lamp.