Abstract: The invention relates to an electrode-inlead assembly for electrical lamps which comprises a lead-in-wire connected to a foil made of refractory metal and the foil is connected to a shank made of refractory metal and supporting the electrode.The object of the invention is, that the shank is made of two parallel rods which are joined by their one end portions, and their opposite end portions are welded to the foil, so that the foil is sandwiched between the rods.

Abstract: This headlamp comprises a reflector and a discharge lamp comprising an inner envelope having a longitudinal axis coinciding with the optical axis of the reflector. The inner envelope includes a bulbous portion, a front leg extending along the optical axis from the bulbous portion toward the front of the headlamp, and a back leg extending along the optical axis from the bulbous portion toward the reflector. The discharge lamp further comprises a tubular shroud comprising a first hollow portion surrounding the front leg of the inner envelope, a second hollow portion surrounding the back leg of the inner envelope, and a bulbous portion between the two hollow portions. The bulbous portion of the shroud has a central longitudinal axis, and this central axis is upwardly offset by a small distance (e.g., at least about 0.5 mm) from the longitudinal axis of the inner envelope on which the discharge is located.

Abstract: A replaceable headlamp bulb for automotive applications comprising a discharge light source, a gimbal device, and a plastic lamp base in which the gimbal device is a one-piece construction that allows the light source to be precisely aligned and locked in a specific position with respect to the lamp base. The gimbal device is a cylindrically shaped member made of glass-mica material with a metallic ring fitted in a castellated circumferential groove at one end of the glass-mica member. The light source is mounted at the opposite end of the gimbal device to the ring-fitted portion. The plastic base contains an internal cylindrical opening into which the ring-fitted end of the glass-mica gimbal is inserted and aligned with respect to the plastic base. The gimbal device is locked inside the plastic base by heating of the metallic ring using Radio-Frequency (RF).

Abstract: A power supply circuit for a gas discharge lamp is disclosed. The power supply circuit includes a circuit for providing a d.c. bus voltage on a bus conductor, and a resonant lamp circuit. The resonant lamp circuit includes a gas discharge lamp, a first resonant impedance in series with the gas discharge lamp, and a second resonant impedance substantially in parallel with the gas discharge lamp. The resonant load circuit operates at a resonant frequency determined by the values of the first and second resonant impedances. Further included is a series half-bridge converter for impressing across the resonant load circuit a bidirectional voltage, and thereby inducing a bidirectional current in the resonant load circuit.

Abstract: An auto-starting lamp system comprises an electrodeless high intensity discharge lamp of the type including an arc tube that contains an ionizable fill, an excitation coil surrounding the arc tube for exciting an arc discharge in the ionizable fill at least during steady state lamp operation, and a starter circuit for facilitating arc discharge of the ionizable fill. The system further comprises a controllable r.f. power source for powering the lamp excitation coil, and an electrical network for matching the impedance of the excitation coil to the impedance of the r.f. power source. The impedance-matching network has the same impedance-matching relation during both lamp start-up and steady state lamp operation. A system controller causes the r.f. power source, during lamp start-up, to ramp up in power to a peak level preferably substantially in excess of a steady state lamp operating power level, and then to decrease from the peak level.

Abstract: An electronic ballast can be connected between either a DC power supply or an AC power supply and a gas discharge lamp, such as a metal halide lamp and control the electrical power supplied thereto. An inverter receives a DC power and generates a periodic waveform at a controlled frequency. A resonant circuit is connected to the inverter and tuned to resonate at a predetermined frequency and generate an output voltage. A coupling capacitor is connected between the resonant circuit and the discharge lamp and supplies the output voltage of the resonant circuit thereto. A controller sets the frequency of operation of the inverter near the resonant frequency of the resonant circuit. The controller is responsive to at least a predetermined set point control voltage and to the output voltage of the resonant circuit. The resonant circuit is tuned to increase the voltage from the inverter means to a level sufficient to cause the discharge lamp to enter a glow mode of operation.

Abstract: An electrodeless discharge lamp comprising an arc tube constructed of a light-transmissive material. An exciting structure surrounds the arc tube and is energizable with radio frequency current to develop an arc discharge. A reflective coating of non-conducting insulating material is disposed on the arc tube wall and is located to reflect light from the arc discharge through the arc tube. The reflective coating and the uncoated portion of the arc tube wall are surrounded by the exciting structure so that light from the arc discharge may reach the reflective coating without blockage by the exciting structure and, following reflection by the coating, travel through the uncoated portion of the arc tube wall.

Abstract: An electric arc discharge lamp includes an elongated hollow tubular transparent envelope having a pair of opposite ends, a pair of electrode mounts respectively disposed in the ends of the tubular envelope, and a dosing capsule defining a hermetically sealed annular cavity containing a predetermined quantity of a dosing liquid therein. The dosing capsule has an inner edge defining an opening through the capsule for receiving a portion of one the electrode mounts therethrough such that the capsule is supported by the one electrode mount with the sealed annular cavity substantially surrounding the one electrode mount. The electrode mount includes a glass stem having inner and outer axially-displaced opposite ends, a pair of lead-in conductors extending through the glass stem and from the opposite ends of the glass stem, and an electrode supported between a pair of inner ends of the lead-in conductors adjacent to and spaced from the inner end of the glass stem.

Abstract: An electrodeless high intensity discharge (HID) lamp arc tube having a stabilized condensate location. The arc tube contains a predetermined location or distortion on the inside surface of the arc tube. The distortion may be a protrusion on the inside surface of the arc tube formed during the arc tube forming process. In operation of the lamp, the non gaseous dose remains condensed substantially in the cold spot region formed by said protrusion so that the arc tube walls remain clear for maximal light output, and the arc tube remains stable and efficacious to substantially higher power than is the case for arc tubes without the distortion.

Abstract: The present invention is directed to a control circuit for providing a substantially constant current to a high-pressure sodium lamp. The control circuit preferably comprises a circuit for providing a rectified voltage signal, and a ballast having first and second contacts to operatively connect the lamp therebetween. The ballast generates and controls a peak current through the lamp based on the value of a controlled voltage. The control circuit further comprises a current sensor to sense the amount of current through the lamp, and a buck-boost voltage control circuit to control the value of the controlled voltage in order to provide a substantially constant peak current through the lamp based on the amount of current sensed by the current sensor. By controlling the amount of voltage seen by the lamp, the buck-boost voltage control circuit controls the amount of current through the lamp, thereby providing constant color temperature regardless of the fluctuations in lamp impedance.

Abstract: An optical coupling assembly is useful for coupling a source of light, having high brightness and focussed at a focal plane, to a plurality of optical light conductors. The coupling assembly includes a light transmissive elongated segmented rod-shaped coupling member formed of a plurality of longitudinal sections and a retainer member for holding the longitudinal sections together in an assembled relationship. The coupling member has a central longitudinal axis and at an input end is disposed at the focal plane of the light source, while at an output end is disposed against leading ends of the plurality of optical light conductors. Each longitudinal section of the coupling member has a plurality of spaced longitudinal surfaces capable of internally reflecting light traveling within the longitudinal section.

Abstract: A high pressure discharge lamp with a thermally improved anode, as well as a method of making such a lamp, are disclosed. The lamp includes a refractory arc tube with a hermetically sealed arc chamber, a fill in the arc chamber for facilitating light generation, and an anode and a cathode extending into the hermetically sealed arc chamber and being spaced apart from each other. The anode comprises a shank of refractory metal, a cylindrically shaped refractory metal sleeve on a portion of the shank, and an end proximally facing the cathode. The anode end comprises a substantially solid mass of refractory metal, and is integrally joined to both the shank and the metal sleeve to facilitate heat flow from the anode end to the shank and sleeve. The anode end preferably is generally shaped as a hemisphere facing the cathode. The refractory metal sleeve is preferably one or more layers of a helically wound refractory metal wire having an outer diameter more than twice a diameter of the shank.

Abstract: A circuit and method for powering a high intensity discharge lamp, such as a high pressure sodium lamp (HPSL) are disclosed. Feedback control is used to achieve a nearly constant amplitude of lamp current so as to attain nearly constant lamp color in a HPSL, and further accommodates considerable variations in a.c. line voltage. The circuit, which shares some features with the method, includes a circuit to supply a d.c. bus voltage and first and second feedback-controlled circuits. The first feedback controlled circuit regulates the bus voltage in response to a first error signal which is derived as a function of peak lamp current and a set point signal for such peak current. The second feedback controlled circuit regulates lamp power in response to a second error signal which is derived as a function of average bus current and a set point proportional to the difference between regulated bus voltage and lamp power.

Abstract: Circuits, and methods of using same, are disclosed for pulse operating a sodium vapor lamp and, in response to gating pulses applied to a resonant ballast, the lamp ignites to develop a quasi-resonant bidirectional current waveform through the lamp, the shape of which is controlled to suppress the excitation of acoustic resonant nodes in the lamp. The quasi-resonant bidirectional current waveform oscillates at a prescribed frequency and contains a first group of harmonics, the harmonic content of which is outside any acoustic frequency region associated with the lamp, and further contains a second group of harmonics having a harmonic content which coincides with such acoustic frequency region. The current waveform is caused to decay substantially at the time of ignition of the lamp to quickly reduce the magnitude of the second group of harmonics to thereby suppress excitation of the acoustic frequency region and prevent arc instability in the lamp.

Abstract: Reflector lamps having vitreous, light transmissive reflectors and containing a source of visible and UV light radiation produce little or no UV radiation in the projected light beam by having a light reflecting coating on the exterior surface of the reflector and the reflector made of UV absorbing glass or having a UV absorbing coating disposed between the light reflecting coating and the exterior reflector surface. An anti-reflecting coating disposed on the interior, light-receiving surface of the reflector reduces UV emission still further.

Abstract: A UV absorbing soda-lime glass containing specific amounts of cerium oxide and iron oxide permits the use of significantly less CeO.sub.2 than is used in prior art glass. The amount of cerium oxide and iron oxide present is 0.02-0.07 wt. % and 0.02-0.06 wt. %, respectively, with a combined total typically no more than 0.13 wt. %. This glass is useful for fluorescent lamp envelopes in absorbing UVB radiation having a wavelength between 280-320 nm, while being transparent to visible light radiation without effecting the color of the light emitted by the lamp.

Abstract: A single-ended low pressure discharge lamp having an Edison base includes at least one U-shaped fluorescent tube having electrode leads which are connected to a ballast arrangement disposed in a housing base. The housing base has an upper part on which the fluorescent tubes are mounted, a connecting part on which a threaded base is mounted and a supporting part formed between the upper part and the connecting part. Lead-in wires are connected from the ballast arrangement to the threaded base in a manner to facilitate automated assembly of the lamp. A first lead in wire connects to the central portion of the threaded base whereas a second lead-in wire connects to the sleeve portion after first passing through a guided opening formed in the housing base between the supporting part and the connecting part.

Abstract: A projection headlamp system for a vehicle includes a high beam subsystem and a low beam subsystem. Each of the high and low beam subsystems includes a pair of light pattern projecting arrangements, a remote single arc discharge light source, a pair of solid optical coupling devices, and a pair of elongated light distributing conductors coupled at output ends to the pair of light pattern projecting arrangements and coupled at input ends to the pair of solid optical coupling devices. The high and low beam subsystems employ either separate single arc discharge light sources or a common single arc discharge light source.

Abstract: An optical coupling assembly is useful for coupling a source of light, having high brightness and being non-coherent and focussed at a focal plane, to a plurality of optical light conductors. The coupling assembly includes an elongated light transmissive coupling member which has a central longitudinal axis and is disposed between the focal plane of the light source and leading ends of the optical light conductors. The elongated coupling member is any one of a limited number of different polygonal cross-sectional shapes. Also, the coupling member can have either a hollow tubular or a solid configuration. The hollow tubular member is coated with a highly reflective material. In one embodiment, the polygonal cross-sectional shape of the coupling member remains constant along the entire axial length of the coupling member.