Abstract: The voltage drop in induction ionized lamps is reduced by utilization of annular magnetic cores of inwardly convex cross section. Core power dissipation may be minimized by use of cores having a circular cross section. Lamp voltage drop may further be reduced by eccentrically positioning the core within a substantially globular lamp enevelope.

Abstract: In an electrodeless fluorescent lamp of the type including a sealed, light transmissive, envelope including an elongate inner wall defining an open-ended cavity and an outer wall surrounding the inner wall to form a generally annular, hollow cavity therebetween, the annular cavity being charged with an ionizable gaseous medium, an induction coil positioned within the open-ended cavity, and a radio frequency oscillator connected to the coil, the coil and the oscillator initiating and maintaining ionization of the medium to form an ultraviolet light emitting discharge, the inner surface of the outer wall of the envelope being coated with a phosphor which emits visible light when excited by ultraviolet light, the improvement wherein the outer surface of the inner wall is coated with a layer of an electrically insulative ultraviolet light reflective material which is overcoated with a phosphor layer. Such improvement yields an increase in visible light production of the order of 50% to 100%.

Abstract: The header and tunnel of an external core, solenoidal electric field, fluorescent lamp are coated with a thin ultraviolet light-reflective layer; for example, aluminum or magnesium oxide. Radiative heat transfer from the lamp plasma to the magnetic core is thus reduced to permit high operating power levels and good lumen maintenance.

Abstract: A high frequency discharge lamp for a spectral-line source includes a discharge envelope in which a substance contributive to the emission of desired spectral lines is contained and in which one electrode is included, the discharge envelope being made of a material, such as quartz, which is electrically insulating and capable of transmitting the spectral lines. A cylindrical metallic container surrounds the discharge envelope and has at a part thereof an opening for taking out the spectral lines. There is further provided means for applying a high-frequency voltage between the electrode and the metallic container.

Abstract: The distribution of turns in the primary winding of an induction ionized discharge lamp varies as a function of angular position on a toroidal core. The turns are wound in proportion to the adjoining secondary plasma flux density. Local matching of flux linkages per ampere reduces leakage flux between the primary and secondary and thereby improves lamp coupling and reduces electromagnetic interference.

Abstract: A solid state microwave power source for providing microwave power to excite an electrodeless lamp is designed so as to provide an acceptable impedance matching characteristic during lamp warm-up when the lamp impedance is high and changing with temperature to provide sufficient power to the lamp during the running state when the lamp impedance is matched to the source. The microwave power source includes a dc power source providing power at variable levels, a microwave oscillator receiving the dc power to produce a microwave signal, and a microwave power amplifier. The oscillator has a transistor in a common base configuration, a microstrip capacitive feedback element to sustain oscillations, and an output impedance matching arrangement formed from microstrip. The microwave signal is amplified in the solid state power amplifier having a power transistor in a common base configuration.

Abstract: Improved efficacy is obtained in an electrodeless light source of the type having a high frequency electrodeless lamp disposed at the ends of inner and outer conductors of a termination fixture by evacuating the region between the lamp envelope and the outer conductor to reduce conductive and convective heat losses.

Abstract: A half wavelength resonant cavity having inner and outer coaxial conductors is coupled at one end to a dc power source, and a gas discharge electrodeless lamp is disposed in the region between the conductors at the other end of the cavity. Repetitive bursts of radio frequency oscillations occur within the cavity, the oscillations causing breakdown of the fill material within the lamp to produce light.

Abstract: A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the DC supply for a microwave power source for the lamp so that a reduced DC voltage is supplied to the microwave power source at lamp starting. An electronic circuit is provided which continuously decreases the DC current through the UV source and increases the DC voltage for the microwave power source in relation to the amount of light generated by the electrodeless lamp. More specifically, the emitter and collector of a transistor are coupled across the UV source to provide a shunt path and the potential of the base of the transistor is controlled by a photosensitive resistor which senses the amount of light from the lamp. As the lamp generates increased light, the transistor becomes more conductive, thereby continuously decreasing current to the UV source and increasing voltage to the microwave power source.

Abstract: A power supply circuit having a crystal controlled solid state oscillator induction coupled to a dual transistor circuit so as to eliminate second harmonics in a coil connected thereto and to a power supply in completing the circuit, and coil further having a resonance circuit therearound. Such power supply being suitable for driving a plasma gas envelope.

Abstract: A starting assist control circuit for an electrodeless light source in which a UV source for assisting in starting an electrodeless lamp is coupled in series with the dc supply for a microwave power source for the lamp so that a reduced dc voltage is supplied to the microwave power source at lamp starting. At staring, a capacitive impedance element is coupled across the inner and outer conductors of the fixture to provide an additional starting assist by creating a condition of resonance in the fixture. A heat responsive bimetallic switch element associated with both the capacitor and the UV source automatically shorts out the UV source and decouples the capacitor after the lamp has started thereby permitting full dc power to the microwave power source during the operating condition of the lamp.

Abstract: An electrodeless RF excited gas arc lamp for pumping a laser has a lamp envelope in the form of a loop having a continuous bore containing krypton, xenon or argon. Sufficient RF power to maintain a plasma in the gas in the loop is provided by a coil around its circumference so that it is linked by the flux generated by RF voltage through the coil. The laser rod to be pumped is mounted adjacent the loop. A diffuse reflector surrounds the lamp and laser rod to reflect back toward the rod light which does not impinge directly on the rod as well as any impinging light not initially absorbed by the rod.

Abstract: A controllable evaporation source of parent metal species, produced either from a volatile metal or a metal halide, and under some circumstances a chemical getter sink in a sealed RF excited discharge. This discharge occurs in a second, extremely pure gas which is present in great excess over the gas produced by evaporization which may be followed by chemical decomposition. Excitation of species whose emission is desired occurs by electron impact or energy transfer from the major species which are in turn, excited by the electron impact.

Abstract: A central portion of the lamp is ionized by a RF field applied between two auxiliary electrodes and the strength of the RF signal resulting between the terminal electrodes of the lamp is measured as an indication of the fill gas pressure.

Abstract: An electrodeless fluorescent lamp adapted for economical substitution in place of existing incandescent lamps comprises an ionizable medium contained within a phosphor coated globular envelope. A closed loop, magnetic core, which may be ferrite, is contained within the ionizable medium to induce an electric field, ionize the medium, and stimulate visible light output. The core, which may be coated with glassy material, is energized by a radio frequency power source in the lamp base structure. Current from the power supply is transmitted to the core by means of a metal rod structure which also serves to transfer heat from within the envelope. A secondary winding on the core provides high starting voltages to initiate a glow discharge.

Abstract: An electrodeless discharge lamp has an ionizable medium comprising a particular gas composition at a particular pressure within a sealed envelope. Radio frequency electrical power is applied to an induction coil, the magnetic induction field of which is coupled to the medium. For a particular radio frequency, the magnitude of the induction field is selected to maximize the light emitted by the discharge per watt of radio frequency power coupled thereto. The radio frequency is preferably between 3 megahertz and 300 megahertz.

Abstract: An electrodeless fluorescent lamp adapted for economical substitution in place of an existing incandescent lamp comprises an ionizable medium contained within a phosphor coated globular envelope. A closed loop magnetic core transformer, contained within a reentrant cavity in the base of the envelope, induces a radio frequency electric field which ionizes the medium to stimulate production of visible light output from the phosphor. A tubular extension of the envelope traverses the cavity, linking the core with a column of ionizable medium, to form a "secondary winding" on the transformer. A base assembly, attached to the envelope, supports a lamp plug for receipt of input energy. A radio frequency power supply, contained within the base assembly, provides electric current to a primary winding on the core.

Abstract: A tunable microwave cavity permits adjustment of the penetration of a power coupling probe into the main cavity by adjusting a grounded element of the cavity. A pair of conductive tubes are in telescoping relationship and have mutually engaging threads so that a rotation of one tube causes one tube to pass over the other. A first one of the tubes is mounted to the main cavity and around an aperture in the cavity wall. A power coupling connector is mounted with the second tube, and a rotating electrical contactor is disposed between the outer conductor of the connector and the second tube so that the connector does not rotate with the second tube. A power coupling probe affixed to the end of the inner conductor of the connector assumes various penetration depths within the main cavity in response to a rotation of the second tube. The cavity may be used in a light source including a high frequency power source and an electrodeless lamp disposed in the main cavity.

Abstract: In a light source excited with power at a high frequency, an electrodeless lamp is located in a termination fixture comprising an inner and outer conductor, the lamp being located at the end of the inner conductor. An internal tuning element is located within the fixture for creating a resonant condition when the lamp is to be started to create a maximum electric field for initiating breakdown and excitation of the fill material within the lamp. The tuner may comprise a variable capacitance coupled in parallel across the conductors at the power input end of the fixture or a variable inductance connected across the conductors at the lamp end of the fixture.

Abstract: A conversion device for converting a resonance photon into a photon characteristic of a molecule whose lowest state is not stable, comprising a resonance lamp emitting light characteristic of a first gas and a conversion cell filled with said first gas and a rare gas. The mixture in said conversion device is illuminated by the resonance radiation characteristic of the first gas by the resonance lamp so as to produce the excited gas atom of said first gas in said conversion device, on which then forms a molecule by association with either first or second species.

Abstract: A light source includes a source of high frequency power, an electrodelsss lamp and a termination fixture for coupling power to the lamp, the fixture having an outer conductor and an inner conductor whose length is adjustable for providing dynamic matching of the impedance of the lamp during the operating mode to the output impedance of the source. Variations in the power level from the source, such as is desirable in providing lamp brightness selectivity, vary both the real and imaginary components of the lamp impedance, and corresponding adjustments of the inner conductor length provide a tuning technique to compensate for these variations.

Abstract: A light source includes an electrodeless lamp having an envelope for enclosing a volatile fill material which emits light upon vaporization and excitation, a source of power at a high frequency and a termination fixture coupled to the source. The fixture has inner and outer conductors which have dimensions such that the lamp is located in the high field region at the end of the conductors. When the high frequency power is applied to the fixture, a voltage standing wave is formed which initiates vaporization and excitation of the fill material. The termination load impedance which is that of the lamp changes from a lossy open circuit to a finite value when vaporization and excitation occur. An impedance matching device is provided for matching the running lamp impedance to the output impedance of the source.

Abstract: In a light source in which an electrodeless lamp is excited by high frequency power coupled into a lamp termination fixture having an inner and outer conductor, the fixture has a dynamically variable characteristic impedance, thereby facilitating dynamic matching of the variable impedance of the lamp during the lamp-off to lamp-run conditions to the output impedance of the power source. This feature is possible because the position of the inner conductor with respect to the outer conductor is controlled as a function of the heat generated within the fixture. The inner conductor is made of a conductive material having a non-uniform coefficient of thermal expansion. When the fixture is cold, the lamp and the lamp-coupled end of the inner conductor are substantially concentric to the outer conductor thereby creating a high characteristic impedance to match the high starting lamp impedance to the source impedance.

Abstract: A termination fixture for an electrodeless lamp has dimensions which match the output impedance of a coupled high frequency power source to the real impedance of the lamp when in a discharge condition. The fixture may consist of a pair of coaxial conductors, and the lamp forms the termination load for the ends of the conductors. The length of the conductors is such as to place the lamp one quarter wavelength from the opposite ends of the conductors. The diameters of the conductors are such as to produce a fixture characteristic impedance which matches the lamp impedance to the source output impedance.

Abstract: An ampoule shaped electrodeless discharge tube, including a large-diameter portion and a small-diameter portion, is filled with luminous elements and inactive gas. The discharge tube is placed in a housing having a lighting window from which the light emitted by the elements is extracted. A high-frequency coil is wound around the large diameter portion at the middle portion of the discharge tube. A partition wall provided in the housing partitions the housing into a first and a second compartments. The middle portion of the discharge tube and the small diameter portion are placed in the first compartment, while the end portion of the discharge tube opposite to the small-diameter portion is placed in the second compartment, and is cooled with air-flow flowing from the inlet to the outlet, both of which are formed to the housing. When high-frequency power is supplied to the coil, the luminous elements in the discharge tube is excited to luminesce.

Abstract: An induction-ionized, electrodeless fluorescent lamp comprises a phosphor coated, globular envelope. An ionizable gas is contained in the envelope to produce radiation which excites the phosphor to produce light. A closed loop, magnetic core lying partially within and partially without the envelope couples radio frequency energy into the gas to produce ionization. The core may be bonded to a metal strap or enclosed in a metal container to improve heat transfer from the surrounding air. Primary windings and heat radiators are attached to the core outside the lamp envelope thereby eliminating the feed-through structures of other lamp embodiments.A radio frequency power supply and lamp base plug are attached to the envelope providing a lamp which is physically and electrically compatible with existing incandescent-type lamp equipment.

Abstract: An electrodeless fluorescent lamp, suitable for substitution in place of existing incandescent lamps, comprises a gas filled toroidal envelope assembly removably mounted around a cylindrical ballast assembly. The ballast supplies radio frequency energy which induces electric current flow within the envelope and stimulates the emission of visible light. A toroidal transformer, which may have a ferrite core, is contained within a constriction on the envelope toroid and couples the energy to the gas. Heat generated within the envelope and transformer is conducted through the ballast to a radiator. The heated surfaces of the ballast and envelope form a chimney which induces air flow over the radiator.

Abstract: An improved termination fixture for an electrodeless light source matches the complex impedance of an electrodeless lamp during excitation to the output impedance of a high frequency power source coupled to the fixture. The inner conductor of the fixture has a first and a second section. The dimensions of the first section are such as to produce an input impedance whose reactive impedance part is much smaller than the reactive impedance part of the lamp impedance. The dimensions of the second section are such as to match the input impedance to the source output impedance.

Abstract: A termination fixture for exciting an electrodeless lamp with high frequency power matches a capacitive complex impedance of the lamp in an excited state to the output impedance of the high frequency source coupled to the fixture. The fixture has a pair of coaxial conductors which have a length of one quarter wavelength and which have a ratio of diameters effective to match the real impedance of the lamp to the impedance of the source. A helical coil couples the end of the inner conductor to the lamp. The purpose of the coil is to make the impedance of the lamp, as viewed, electrically, from the end of the inner conductor appear as having only the real component. The quarter wave fixture then matches the real impedance to the source impedance.

Abstract: A lamp holding fixture for exciting an electrodeless lamp by high frequency power has a switchable characteristic impedance for impedance matching the lamp to the power source during both the starting and operating modes. The fixture has an inner conductor and two outer conductors of different dimensions in cross section. During the starting mode the inner conductor and the larger diameter outer conductor form the power coupling conductors for the fixture thereby providing a high characteristic impedance for matching the lamp impedance to the source output impedance. After starting, the smaller diameter outer conductor may be moved along its longitudinal axis until it contacts the power coupling end of the larger diameter outer conductor so that the inner conductor and the smaller diameter outer conductors form the power coupling conductors during the operating mode.

Abstract: A termination fixture for use in an electrodeless light source has an input impedance which is matched to the output impedance of a high frequency power source, even though the lamp which forms the termination for the fixture has a complex impedance when the lamp is in an excited state. The fixture has a pair of coaxial conductors of at least a quarter wavelength, the conductors being coupled to the source at one end and to the lamp at the other end. The conductors are shaped to create an impedance which matches the real component of the lamp impedance to the source impedance. A capacitor is formed across the inner and outer conductors at the source coupled end to compensate for the series capacitive reactance part of the lamp impedance at the lamp coupled end of the conductors.

Abstract: An electrodeless lamp is excited in a termination fixture by high frequency power, the lamp being located within the fixture at the end of an inner conductor whose end is shaped such as to inhibit the arc of the lamp from attaching to the lamp envelope. In one embodiment, the inner conductor end is shaped as a hollow helical coil which generates an axial and azimuthal electric field component to create a torodial arc within the lamp. In another embodiment the inner conductor end is cup-shaped to provide a field shielding effect which distributes the field strength more uniformly across the end of the inner conductor.

Abstract: An electrodeless lamp is positioned at the end of an inner and outer conductor forming a termination fixture, the inner conductor being shaped such that the arc within the lamp during excitation is isolated from the wall of the lamp envelope. The inner conductor may be formed as a hollow helical element thereby providing both an axial and azimuthal electric field component. Alternatively, the inner conductor may be cup-shaped which has a shielding effect to control the electric field strength at the end of the conductor. The helical or cup element and other features of the inner conductor provide both arc shaping and impedance matching between the complex impedance of the lamp during operation and the output impedance of a high frequency power source which is coupled to the termination fixture.