Abstract: A dielectric barrier discharge device in which uniformity of the light irradiation energy density is achieved, even if dielectric barrier discharge lamps have variations with respect to the lamp material and the processing. The dielectric barrier discharge device has at least one dielectric barrier discharge lamps and a feeder device for applying an AC high voltage to the electrodes of the dielectric barrier discharge lamp, the dielectric barrier discharge lamp having a discharge gas-filled discharge gap which produces excimer molecules by a dielectric barrier discharge and one dielectric between at least one of the electrodes and the discharge gap for inducing the discharge phenomenon in the discharge gas.

Abstract: An electrodeless discharge lamp having a gas filling consisting of a gas mixture for generating gas-specific resonance radiation, wherein the lamp vessel is made of glass. To facilitate replacement and mounting of the electrodeless lamp, the discharge lamp is arranged within a metallic housing and the lamp vessel is disposed together with the high frequency coil as well as any electronic elements on a printed circuit board which is connected with the cover of the lamp housing.

Abstract: Disclosed are a backlight and a method of driving the same to provide a uniform low intensity source of light for a liquid crystal display. The fluorescent lamp includes a fluorescent lamp and a drive circuit coupled to the anode and to the cathode of the fluorescent lamp for supplying the fluorescent lamp with a drive current. First and second longitudinally extending substantially transparent conductor members are disposed externally along the length of the lamp. A radio frequency (RF) signal generator connected to each of the first and second longitudinally extending conductor members drives the first and second conductor members with an RF signal to generate a dynamic RF electric field within the glass tube.

Abstract: An electrodeless fluorescent reflector lamp includes a housing arrangement having a threaded screw base for receiving line power and a lamp envelope mounted on the housing arrangement. A ballast circuit is disposed within the housing arrangement and is effective for converting line power into an RF signal which excites a fill contained within the lamp envelope to a discharge state thereby resulting in the production of visible light. The lamp envelope is constructed having an upper curved face portion and a lower tapered portion which extends partly within the housing. A reflective coating is applied to the lower tapered portion of the lamp envelope. A phosphor coating distribution is applied to the interior surface of the lamp envelope in a manner so as to maximize the light output from the reflector lamp.

Abstract: A high intensity discharge lamp without mercury is disclosed radiating a selected spectrum of which can be almost entirely in the visible range from an envelope that contains a sulfur containing substance. The lamp utilizes a signal source that generates an excitation signal that is externally coupled to the exterior surface of the envelope to excite the enclosed sulfur containing substance. Various embodiments of the lamp use electrodes adjacent the envelope to couple the excitation signal thereto with the face of the electrodes shaped to complement the shape of the exterior surface of the envelope. Two shapes discussed are spherical and cylindrical. To minimize filamentary discharges each envelope may include an elongated stem affixed to the exterior thereof whereby a rotational subsystem spins the envelope.

Abstract: A lighting unit comprises an electrodeless low-pressure discharge lamp (10) and an electric supply (60) for the lamp. The lamp is provided with a discharge vessel (20) having a radiation-transmitting enveloping portion (21) and a recessed portion (24). The discharge vessel encloses a discharge space (27) in a gastight manner and contains an ionizable filling. The lamp also is provided with a coil (30) positioned in the recessed portion for generating a high-frequency magnetic field so as to maintain an electric discharge in the discharge space. The enveloping portion (21) of the discharge vessel is provided with a radiation-transmitting, electrically conducting layer (22) at a surface facing the discharge space (27). This layer is electrically connected to a lead-through member (42) which issues to the exterior of the discharge vessel. The lead-through member is a metal tube which forms at least a portion of a tubular projection (46, 42, 47).

Abstract: An electrodeless lamp waveguide structure includes tuned absorbers for spurious RF signals. A lamp waveguide with an integral frequency selective attenuation includes resonant absorbers positioned within the waveguide to absorb spurious out-of-band RF energy. The absorbers have a negligible effect on energy at the selected frequency used to excite plasma in the lamp. In a first embodiment, one or more thin slabs of lossy magnetic material are affixed to the sidewalls of the waveguide at approximately one quarter wavelength of the spurious signal from an end wall of the waveguide. The positioning of the lossy material optimizes absorption of power from the spurious signal. In a second embodiment, one or more thin slabs of lossy magnetic material are used in conjunction with band rejection waveguide filter elements. In a third embodiment, one or more microstrip filter elements are tuned to the frequency of the spurious signal and positioned within the waveguide to couple and absorb the spurious signal's energy.

Abstract: In some embodiments, a light bulb for an electrodeless discharge lamp has a protuberance such that the cold spot of the bulb is located in the protuberance. The protuberance is spaced from the induction coil of the lamp so as to be easily accessible. Hence the cold spot temperature is easy to measure and control. In some embodiments, heat sinks are provided to cool the light bulb. An active control element including a Peltier element is provided to control the cold spot temperature.

Abstract: A microwave-excited discharge lamp (2) is constructed with a double-case structure consisting of an outer case (3) disposed in a microwave electromagnetic field, and an inner case (4) disposed inside the outer case.

Abstract: A method wherein the light in a sulfur or selenium lamp is reflected through the fill a multiplicity of times to convert ultraviolet radiation to visible. A light emitting device comprised of an electrodeless envelope which bears a light reflecting covering around a first portion which does not crack due to differential thermal expansion and which has a second portion which comprises a light transmissive aperture.

Abstract: An electrodeless low-pressure discharge lamp according to the invention has a lamp vessel (1) which is closed in a gastight manner, which contains an ionizable filling, and which has a cavity (10). In the cavity (10) an elongate coil (2) is positioned with a primary and a secondary winding (21, 22, respectively) of an electrical conductor (20) around a coil former (3) which has a tip (30) which points into the cavity (10). The electrical conductor (20) from which the secondary winding (22) is formed extends from a first end (22a) of the secondary winding (22) facing the tip (30) into a recess (32) of the tip (30) of the coil former (3) and is clamped therein. The first end (22a) of the secondary winding (22) can be easily fastened in this manner.

Abstract: A structure for eliminating the noise in a light source device for an electronic endoscope safely eliminates the high-frequency noise produced from the lighting circuit, the xenon lamp and the like in the light source device. A capacitor for eliminating noise having a predetermined withstand voltage is connected between the support of the lighting circuit and the box body of the light source device so as to introduce the noise current produced by the switching operation of the lighting circuit to the ground. EMI springs are disposed between the outer peripheral surface of the conductive case of the lighting circuit and the xenon lamp and the inter peripheral surface of the box body of the light source device. A ferrite core for eliminating noise is provided on a conductive wire connecting the lighting circuit and the xenon lamp, thereby safely eliminating noise.

Abstract: A method and apparatus for exciting an electrodeless light bulb containing material including an inert gas and one or more chemical elements which generate a light emitting torus of plasma when excited by an RF signal and which includes two separate excitation coils oriented about the bulb so that the planes of each of the coils are mutually oriented 90.degree. with respect to each other, and wherein each of the coils are driven by respective RF excitation voltages having mutually different frequencies, for example, a difference of 4%, so as to excite the material enclosed within the bulb and cause a stirring action of the fill and effect a pulsating emission of light and rotation of the torus similar to that produced by physical rotation of the bulb itself.

Abstract: A power supply for an electrodeless lamp having an exterior starting electrode and first and second magnetrons coupled to the lamp comprises first and second power sources for being connected to the respective first and second magnetrons; a switch having first and second positions, the first position for disconnecting the second power source from the second magnetron and connecting the output of the second power source to the output of the first power source such that they are added together for being connected to the first magnetron during starting of the lamp, the second position for disconnecting the second power source from the first magnetron and connecting the second power source to the second magnetron after the lamp has started; and a controller adapted to synchronize the starting of the first and second power sources and the starting electrode such that they are turned on at the same time during starting of the lamp.

Abstract: An electric lamp assembly includes an electrodeless lamp having an electrodeless lamp envelope enclosing a fill material for supporting a low pressure discharge, a driving inductor including a magnetic core disposed in proximity to the lamp envelope and an input winding disposed on the magnetic core, a compensation loop disposed in proximity to the lamp envelope, a radio frequency power source and a compensation loop network. The compensation loop network has an input coupled to the radio frequency power source and outputs coupled to the input winding and to the compensation loop. The radio frequency power source and the compensation loop network supply radio frequency energy to the electrodeless lamp to produce a discharge in the lamp envelope and supply radio frequency energy to the compensation loop to generate a magnetic field that substantially counteracts a magnetic field produced by the discharge.

Abstract: A coil extension of the RF coupling coil, surrounding an electrodeless light bulb containing an inert gas and selected chemical elements, generates a voltage at the distal end thereof which is higher than that which appears across the RF coupling coil proper, and wherein the high voltage from the distal end of the coil extension is returned to the light bulb through a point contact electrode located in relatively close proximity to the low voltage end of the RF coupling coil.

Abstract: A ballast for an electrodeless gas discharge lamp comprises a load circuit including an r.f. inductor for generating an r.f. field for powering the electrodeless lamp and a serially connected resonant capacitance. The inductance of the r.f. inductor has a substantial effect in determining a frequency of resonance the load circuit. A d.c.-to-a.c. converter circuit is coupled to the load circuit for inducing a.c. current therein. It comprises first and second converter switches serially connected in the foregoing order between a bus node at a d.c. voltage and a reference node, and being connected together at a common node through which the a.c. load current flows. The first and second converter switches each has a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the first and second converter switches are interconnected.

Abstract: An electrodeless gas discharge lamp includes a vitreous envelope containing a discharge medium. An excitation coil is positioned in relation to the vitreous envelope so as to excite the discharge medium therein. The excitation coil is adapted to be driven by an RF oscillator. The excitation coil has first and second ends and is effective for exciting the discharge medium to emit light with electromagnetic fields that are generated by the excitation coil. The excitation coil includes a first wire wound generally helically from the first end to the second end in a first helical direction to form first winding turns, and further includes a second wire wound generally helically from the first end to the second end in second helical direction opposite to that of the first helical direction to form second winding turns. Preferably, a generally cylindrical former is provided for holding the first and second wires between the first and second ends of the coil.

Abstract: In a microwave powered electrodeless lamp, a single rotary motor is used to a) rotate the bulb and b) provide rotary motion to a blower or pump means for providing cooling fluid to the magnetron and/or to a forced gas cooling for providing cooler gas to the bulb. The blower may consist of only of an impeller without the usual blower housing. The motor, bulb stem and bulb, or motor, bulb stem, bulb and blower may be formed as an integral unit so as to facilitate replacement.

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 electrodeless light bulb assembly having a standard light bulb base located at one end of an extruded cylindrical heat sink including a set of elongated fins extending radially outward from an annular inner body portion. An electrodeless light bulb, excitation coil, and transparent cover for the bulb are located at the other end of the heat sink. A solid state electrodeless lamp driver circuit is thermally coupled to the heat sink and is located in a hollow inner space region formed by the inner body portion. The annular inner body portion also includes at least one but preferably a plurality of boiler/condenser heat pipes located around its periphery for thermally coupling the heat from excitation coil and the driver to the fins where heat is transferred to the air via natural convection. The excitation coil can be formed from a length of conventional electrical conductor or it can be formed from a length of heat pipe connected at one end to the driver and at the other end to the heat sink.

Abstract: Ignition of an electrodeless lamp, energized by microwave or radio frequency energy, is achieved by disposing a ferroelectric igniter in the lamp envelope along with the fill material. The igniter responds to switching of its spontaneous ferroelectric polarization by emitting electrons that collide with the atoms of the fill material to discharge further electrons and ultimately provide emission of light. In the preferred embodiment, the microwave or radio frequency energy used to excite the fill material is applied to the ferroelectric igniter to cause switching of its spontaneous ferroelectric polarization. Another preferred feature is the securing of the igniter, in the form of a thin patch or wafer, to the inside surface of the lamp envelope in a generally perpendicular orientation to the electric field in the microwave excitation energy.

Abstract: An electrodeless lamp capsule includes 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, and a lamp stem attached to the discharge envelope. The lamp stem includes a first section having a first cross-sectional area and a second section attached to the discharge envelope. The second section of the lamp stem has a second cross-sectional area that is less than the first cross-sectional area. The lamp stem may be a tube having a longitudinal slot which defines spaced-apart, first and second elements that are attached to the discharge envelope. The first and second elements have a relatively small total cross-sectional area for conducting heat from the discharge envelope and permit secure attachment of the lamp stem to the discharge envelope.

Abstract: A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector secured at the juncture of the two sections to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. The reflector is mounted in the cavity by tabs formed in the screen unit and bendable into the cavity to define support planes abutting respective surfaces of the reflector. The mesh section and tabs are preferably formed by etching a thin metal sheet.

Abstract: At least one amalgam, which is disposed within the lamp envelope of an electrodeless fluorescent lamp to control mercury vapor pressure, is mechanically supported by an amalgam support arrangement in a manner non-invasive to the lamp envelope. The amalgam support arrangement supports one or more amalgams in a "flag" configuration and includes a support member, one end of which is configured for friction-fitting within the exhaust tube opening. The flag may be configured as a wire mesh or spiral-shaped wire, for example. Exemplary configurations for this end of the support member include a U-shape, spiral, zig-zag, or tubular configuration.

Abstract: An electrodeless light bulb assembly including a case or housing supporting an electrodeless light bulb as well as a convection type heat exchanger. A solid state RF driver circuit is located inside the housing and connects to an excitation coil wrapped around the light bulb. The excitation coil comprises a metal heat pipe so as to provide an efficient thermal transport mechanism for the heat generated by the coil and the heat radiated thereto from the electrodeless bulb to the heat exchanger in addition to generating an RF excitation field for the electrodeless light bulb.

Abstract: An excitation circuit for an electrodeless light bulb which includes an RF source, a driver amplifier, and a load matching network and where the frequency of the RF energy generated by the source is swept over a predetermined frequency range in a controlled manner by a programmable frequency controller to cover the entire range of possible load match tuning conditions so that the electrodeless bulb will be substantially matched at all times to the source at some frequency in the sweep range.

Abstract: An electrodeless lamp arrangement powered by RF energy. The lamp arrangement having an envelope that is rotated and most importantly the envelope forms the center of a coaxial arrangment used to transfer the RF energy into the envelope.

Abstract: An electrodeless lamp comprises an envelope containing a fill; a starting electrode in proximity to a given region of the envelope when lamp is started; a field emission source disposed inside the envelope at the given region; starting power source coupled to the electrode for applying an electric field to the field emission source to cause a discharge; and excitation power source coupled to the fill to sustain the discharge. A method for starting an electrodeless lamp is also disclosed, comprising the steps of providing bulb comprised of an envelope and a discharge forming fill in the envelope; providing a field emission source on an interior surface of the envelope at a given region; applying an electric field at the given region to cause field emission from the field emission source to cause a discharge; and coupling a power source to the fill to sustain the discharge.

Abstract: A power supply quickly restarts an electrodeless lamp which is temporarily turned off in an application using microwave radiation generated by a magnetron. When the electrodeless lamp operates in a full power mode, the power supply provides full power to the magnetron via high DC current and high DC voltage. When a user selectively switches the electrodeless lamp off, less power is provided to the magnetron than in the full power mode. In the reduced power mode, the magnetron generates sufficient microwave radiation to maintain the bulb plasma in an ignited condition while the lamp produces substantially no light output. This eliminates the required cooldown delay associated with the lamp shut down and quickly brings the lamp to the full power operation when requested by the user.

Abstract: A fluorescent illuminating apparatus includes a translucent housing with a chamber within which a fluorescent medium is supported. The fluorescent medium and housing may be part of an ordinary fluorescent lightbulb. The housing has electrical connections configured to provide an electrical potential across the chamber. An inductive structure is fixed sufficiently proximate to the housing to induce fluorescence in the fluorescent medium when an electric current is passed through the inductive structure while an electric potential is applied across the electrical connections of the housing. It is believed that the inductive structure induces fluorescence by means of an electromagnetic field interaction with either the fluorescent medium, or the ultraviolet-emitting gaseous material, such as mercury, typically contained in a fluorescent lightbulb, or both.

Abstract: A lamp for emitting in the visible portion of the spectrum, which utilizes a fill which includes a selenium and/or a sulfur containing substance. The lamp has superior performance characteristics, including long lifetime and excellent color rendition. The bulb may be either electrodeless or electroded, and may contain additives for emphasizing a desired spectral region.

Abstract: EMI suppression in electrodeless discharge lamps by inward RF-reflectance from the enclosure walls (12) of 90%+ and use of an absorber (16) of RF power having an absorption coefficient greater than 40%, a transmission coefficient less than e.sup.-3, and an effective area facing the interior of the enclosure between 5% and 40% of the area of the RF-reflective light transmissive enclosure.

Abstract: An electric lamp assembly includes an electrodeless lamp having a closed-loop, tubular envelope enclosing mercury vapor and a buffer gas at a pressure less than about 0.5 torr, a transformer core disposed around the lamp envelope, an input winding disposed on the transformer core and a radio frequency power source coupled to the input winding. The radio frequency source supplies sufficient radio frequency energy to the mercury vapor and the buffer gas to produce in the lamp envelope a discharge having a discharge current equal to or greater than about 2 amperes. The electrodeless lamp preferably includes a phosphor on an inside surface of the lamp envelope for emitting radiation in a predetermined wavelength range in response to ultraviolet radiation emitted by the discharge.

Abstract: A sulfur, selenium, and/or tellurium based lamp for providing visible light. The lamp is operated in a regime for providing high efficacy wherein the ratio of the volume to surface area of the bulb is greater than 0.45 cm, the concentration of the sulfur, selenium, or tellurium is less than 1.75 mg/cc, and the power density is between about 100 watts/cc and 5 watts/cc.

Abstract: A high intensity discharge lamp without mercury is disclosed radiating a selected spectrum of which can be almost entirely in the visible range from an envelope that contains a sulfur containing substance. The lamp utilizes a signal source that generates an excitation signal that is externally coupled to the exterior surface of the envelope to excite the enclosed sulfur containing substance. Various embodiments of the lamp use electrodes adjacent the envelope to couple the excitation signal thereto with the face of the electrodes shaped to complement the shape of the exterior surface of the envelope. Two shapes discussed are spherical and cylindrical. To minimize filamentary discharges each envelope may include an elongated stem affixed to the exterior thereof whereby a rotational subsystem spins the envelope.

Abstract: An electrodeless lamp assembly includes an electrodeless lamp capsule, a substrate having top and bottom surfaces and an edge, an applicator for coupling electrical energy to the lamp capsule and a refractory support block. The support block includes a top wall having a recess and a side wall having a groove. The lamp capsule is affixed in the recess, and the edge of the substrate is secured in the groove. The lamp capsule is supported above the substrate by the support block. During assembly, the support block may be moved along the edge of the substrate, and the lamp capsule may be moved with respect to the support block to adjust the position of the lamp capsule.

Abstract: A microwave powered electrodeless lamp includes an improved screen unit having mesh and solid sections with an internal reflector to reflect light into a light-transmitting chamber defined in the lamp microwave cavity by the reflector and the mesh section. A discharge envelope of a bulb is disposed in the light-transmitting chamber. Light emitted from the envelope is prevented by the reflector from entering the cavity portion bounded by the solid section of the screen. Replacing mesh material by solid metal material as part of the screen unit significantly reduces leakage of microwave energy from the lamp. The solid section has multiple compliant fingers defined therein for engaging the periphery of a flange on the waveguide unit so that a hose clamp can easily secure the screen to the assembly. Screen units of this type having different mesh section configurations can be interchanged in the lamp assembly to produce different respective illumination patterns.

Abstract: An electrodeless low-pressure discharge lamp according to the invention comprises a light-transmitting discharge vessel which is provided with an ionizable filling. The discharge vessel has a cavity in which an electric coil is arranged which is provided with a primary and a secondary winding around a metal body, the primary winding of the coil being connected to a first and a second electrical conductor of a cable for connection to a first and a second output terminal of a high-frequency supply the second output terminal of the supply being free from high-frequency voltage variations relative to ground (M). The secondary winding is connected at one of its ends to the second electrical conductor and has a further, free end. The electrical conductors are electrically insulated from one another, the second electrical conductor surrounding the first electrical conductor. The metal body is capacitively coupled to the second electrical conductor.

Abstract: An electrodeless fluorescent lamp having a lamp envelope with an inner phosphor coating and containing a fill capable of sustaining a discharge when suitably excited by an electric field includes an electrically conductive coating on the exterior of the lamp envelope. The electrically conductive coating is also light transmissive and is effective for confining the electric field to within the lamp envelope.

Abstract: An electrodeless low-pressure discharge lamp according to the invention is provided with a lamp vessel which is closed in a gastight manner and which has an ionizable filling. The lamp vessel has an end portion with a cavity in which an electric coil is accommodated. The cavity further contains a heat conductor which extends to outside the cavity and has a flange there with an axis, a circumference, a surface which faces away from the lamp vessel and a surface which faces the lamp vessel. A mounting member is connected to the lamp vessel and fastened against the flange. The mounting member is provided with at least one hook which points radially inwards and which cooperates with a recess in the surface of the flange which faces away from the lamp vessel. The recess issues into an axial groove at the circumference of the flange extending into the surface facing the lamp vessel. This construction renders possible a quick assembly of the mounting member with the flange.

Abstract: Disclosed herein is a reflector system for a lighting fixture having a illumination source surrounded by an envelope. The reflector system includes a first reflector surrounding the illumination source. The reflector system also includes a second reflector which is non-contiguous with the first reflector and which surrounds the illumination source. The illumination source creates light rays which are reflected by the first and second reflectors. The first reflector directs light rays toward the center line of the fixture. However, the reflected rays despite being so reflected do not substantially intersect the envelope. The reflected light rays from the second reflector being directed so that they diverge from the center line of the fixture avoiding intersection with the semi-transparent envelope.

Abstract: A discharge vessel (10) closed in a gastight manner has a cavity (11) enclosing a discharge space provided with an ionizable filling. A coil (20) with a winding (21) of an electric conductor and an assembly (30) of a heat conductor (31) and one or several elongate cores (32) of soft-magnetic material are accommodated in the cavity. The cores (32) are arranged along a longitudinal axis (33) of the heat conductor (31) in one or several recesses (34) of the heat conductor which issue into a circumferential surface (36) of the assembly (30). The heat conductor (31) occupies at least half the circumference in a cross-section perpendicular to the longitudinal axis (33) of the assembly (30). The construction of the lamp according to the invention renders possible lamp operation at higher lamp powers also without the use of a heat pipe.

Abstract: An amalgam system for optimizing the mercury vapor pressure of an electrodeless discharge fluorescent lamp is disclosed. A coil network induces an electric discharge in a gas mixture contained in a sealed lamp vessel. An amalgam is supported in the discharge and thermally isolated from the lamp vessel by a thin glass strand. The discharge transfers power directly to the amalgam, thus quickly heating the amalgam. Rapid heating of the amalgam provides a rapid increase in mercury vapor pressure in the lamp so that the light output rises quickly when the lamp is energized. An impedance matching and filter network is constructed such that, in combination with the coil/plasma load, it provides a desired steady-state impedance and a desired start-up impedance.

Abstract: An electrodeless fluorescent lamp includes a feedthrough structure extending from the exterior to the interior of the lamp which is constructed of a suitable material, e.g., platinum or a combination of platinum and rhodium, for directly connecting an interior EMI shield to ground. The feedthrough is also suitable for supporting an amalgam flag.

Abstract: The spectral energy characteristic of a discharge lamp is controlled by changing the density of the fill substance. The spectral characteristic can be shifted while substantially maintaining its shape by changing the density of the fill. A sulfur or selenium containing discharge lamp which is operated at a pressure of at least about 1 atmosphere contains a low ionization potential substance in the fill. Characteristics which are improved are one or more of spatial color uniformity, extinguishing characteristics, and bulb starting reliability. Particular substances which are added to the fill are alkalai metal containing substances, III B metal containing substances, and alkaline earth metal containing substances. When light is reflected back into the bulb, the light which is re-emitted is stronger in the higher wavelengths.

Abstract: An electrodeless lamp is started by coupling microwave power of a first frequency to a lamp cavity, while the discharge is maintained by coupling microwave power of a second frequency, wherein the first frequency is lower than the second frequency. A cooling fluid is impinged on the lamp bulb immediately before the application of the microwave power of the first frequency.

Abstract: For a given lamp size and lumen power, an electrodeless fluorescent lamp is configured with a split excitation coil and a baffle structure to provide multiple discharges, resulting in a higher light output and higher luminous efficacy.

Abstract: An electrodeless low-pressure discharge lamp is provided with a lamp vessel which is closed in a gastight manner, which surrounds a discharge space, and which contains a filling of mercury and rare gas. The lamp vessel has a cavity and a collar where the cavity is open towards the exterior, an electric coil being accommodated in the cavity and support with an amalgam being arranged in the discharge space. The collar is made of metal and the support of the amalgam is fastened to the collar. This construction counteracts degeneration of the amalgam.

Abstract: An electrodeless discharge lamp includes a single type auxiliary electrode for preliminary discharging, disposed on or adjacent to outer peripheral wall of lamp tube at a position for being electrostatically coupled to interior space of the tube, and supplied with a power from a second high frequency power source other than a first high frequency power source supplying a high frequency power to a main induction coil on the tube, whereby the lamp is made to attain an excellent startability without requiring any large size high frequency power source.