Abstract: A condensed power supply circuit for powering a gas discharge lamp with bi-directional current reduces duty cycle by increasing dead time. The circuit comprises an arrangement for supplying d.c. power from an a.c. voltage, a series half bridge converter, a boost converter, a resistor-capacitor delay circuit associated with a gate to control dead time, and a snubber capacitance for facilitating zero voltage switching to fill the entire dead time. The series half-bridge converter alternately impresses a d.c. bus voltage from a bus conductor across a load circuit first with one polarity and then with an opposite polarity. The series half-bridge converter includes a first switch, a second switch, and a switching control circuit for alternately switching on the first and second switches. The boost converter comprises a boost capacitor, a boost inductor, and means for periodically connecting a load end of the boost inductor through a low impedance path to the ground conductor, thereby charging the boost inductor.

Abstract: A metal halide arc discharge lamp rated for not more than 150 watts and 100 volts and which can be operated in either a horizontal or vertical position without a significant change in color temperature or lumen output has an ellipsoidal arc chamber mounted within a nitrogen-containing outer envelope. The arc chamber contains a pair of electrodes, mercury and sodium and scandium iodides and is coated at each end with a heat reflective coating. The chamber aspect ratio, electrode insertion length, metal halide density, coating length and wall loading are defined within narrow ranges.

Abstract: An electrodeless, low pressure gas discharge lamp includes a vitreous envelope containing a discharge medium and being shaped with an external chamber for receiving an electrical excitation circuit. The excitation circuit is effective for exciting the discharge medium to emit light with electromagnetic fields that are generated by the excitation circuit. A circuit is included for supplying electrical power from power mains to the excitation circuit. A transparent, electrically conductive coating is provided atop the vitreous envelope and is electrically connected substantially directly to one of the power mains at any given time. A transparent, electrically insulative coating is disposed atop the electrically conductive coating, and comprises a contiguous, inorganic glass layer. The insulative coating preferably has a minimum coating thickness of at least about 3.1 microns.

Abstract: A low pressure discharge lamp, particularly a compact fluorescent lamp, achieves an overall reduction in height by orienting ends of the envelope radially inward for connection to the base. This advantageously positions the electrodes housed within the envelope away from the base. Moreover, this mounting arrangement provides resistance against pull out forces and elimination of a cement to secure the envelope to the base, as well as other improved heat transfer benefits.

Abstract: Disclosed is a ballast circuit for a gas discharge lamp, including a resonant load circuit with a gas discharge lamp and first and second resonant impedances whose values determine the operating frequency of the resonant load circuit. The ballast circuit further includes a d.c.-to-a.c. converter circuit coupled to the resonant load circuit so as to induce an a.c. current in the resonant load circuit. The converter circuit comprises first and second switches serially connected between a bus conductor at a d.c. voltage and ground, and has a common node through which the bidirectional load current flows. A feedback arrangement regeneratively controls the first and second switches, and includes a circuit for sensing a.c. current in the resonant load circuit and producing a feedback signal in proportion to the a.c. current.

Abstract: Disclosed is a fluorescent lamp and ballast arrangement of the type having a lamp base for connection to a fixture that also accommodates a lamp base of an incandescent lamp. A ballast circuit contains a first conversion circuit which converts a.c. voltage to d.c. voltage and which has an electrolytic capacitor for smoothing the d.c. voltage. The ballast circuit further includes a second conversion circuit which converts the d.c. voltage into a.c. current and which includes a resonant inductor and resonant capacitor. A ballast housing has first and second ends spaced along a longitudinal axis of the housing and encloses parts of the ballast circuit. Only two lamp tube portions of the lamp terminate in the first end of the ballast housing, with the resonant inductor being positioned between the two lamp tube portions.

Abstract: The cap according to the invention has a base plate and a side wall and in the base plate, openings are formed for accepting the glass body or bodies of the lamp envelope. Optionally, a partition is placed between the side wall and these openings. The essential feature of the invention is that the cap has, in its inner space bordered by the side wall, or optionally by the partition, components extending to at least one opening and bordering a smaller space at its side, the smaller space being intended to accept an adhesive and is also bordered by some portion of the base housing.

Abstract: A fluorescent lamp includes a lamp tube having first and second ends and containing fill materials for causing light generation when provided with electrical power. The lamp further includes first and second power-transferring means at the first and second ends of the lamp tube, respectively, for providing the fill materials in the lamp tube with electrical power. Also included is a thermal heat shield separating the first power-transferring means from ballast circuitry which supplies power to the first power-transferring means and which has a lifetime that becomes substantially less as its operating temperature increases. The thermal heat shield is constructed so that it reflects back to the first power-transferring means and any adjacent portion of the lamp tube sufficient radiant energy to reduce the operating temperature of the ballast circuitry by more than about one degree Celsius compared with the absence of the heat shield.

Abstract: A compact optical coupling member is useful for coupling non-coherent light from a source of light to a light distribution harness. The coupling member includes an elongated light transmissive body having a central longitudinal axis, an inlet end for receiving light from the light source, and an outlet end for providing light to a leading end of a light distribution harness. The elongated body has a polygonal cross-sectional shape for providing increased light mixing of the non-coherent light. The polygonal shape of the elongated body increases in size from a first cross-sectional area at the inlet end to an enlarged cross-sectional area at the outlet end for reducing, with respect to the longitudinal axis, the maximum angle of light passed through the outlet end relative to the maximum angle of light received through the inlet end.

Abstract: A low-pressure mercury vapor discharge lamp (10) includes a tubularly-shaped envelope (12) sealed at each end with a stem assembly (14). A fluorescent coating (26) is disposed on the interior surface of the envelope (12) and an electric discharge sustaining fill gas is provided within a hollow interior (24) of the envelope (12). Each stem assembly (14) includes a glass base portion (30) which seals the end of the envelope (12), an electrode (16), and a tubularly-shaped, light-transmissive, glass shield (22). The electrode (16) is disposed within the envelope (12) such that an electric discharge occurs between the electrodes (16) upon operation of the lamp (10). The glass shield (22) extends past the electrode (16) to partially surround the electrode (16) and shield the interior surface of the envelope (12) from material ejected from the electrode (16). The glass shield (22) allows the electric discharge to unaffectedly pass through an open end (42).

Abstract: A lenticular lens containing a multiplicity of multi-sided lenticules useful with reflector lamps provides improved light distribution by having the lenticules oriented to avoid parallelism with a projected light image and distributed in a plurality of zones or bands concentric about said optical center. The size and light-spreading ability of the lenticules in each zone is selected to provide the desired light distribution. Parallelism is avoided by having the lenticules arrayed in a plurality of wedge-shaped sections circumferentially arranged in a circle around the optical center of the lens and extending through the zones with the lenticules in each section arrayed in a uniform, close-packed hexagonal array of parallel rows with the longitudinal axis of one of the rows being radially aligned with respect to the optical center of the lens, so that none of the sides of the lenticules are parallel to the light source image projected off the reflector.

Abstract: A lamp is provided with a mounting arrangement for achieving a precise alignment. The lamp includes a double-ended light source, a metal strap clamping one end of the light source at two locations, and a plastic base having an internal opening wherein the metal strap is engaged. The metal strap includes two clamping members between which the light source is clamped and a cap member attached to the clamping members. The cap member has tabs adapted for engaging the internal opening of the plastic base and gimbaling the light source to align the light source with respect to the plastic base. The clamping members are joined together at a point between the to clamping locations such that a spring force clamps the light source. The clamping members are also oriented at an angle of about 45 degrees from vertical to better withstand both vertical and horizontal loads.

Abstract: A compact fluorescent lamp is provided in a coiled or helical configuration in order to maximize the length of discharge tubing for a given height. A non-uniform coating of phosphor is provided on the interior surface of the discharge envelope to inhibit light otherwise directed inwardly into the lamp toward a longitudinal axis of the helical configuration and redirect the light outwardly through an outer circumferential portion having a thinner phosphor coating. This results in increased light output for an given lamp geometry and lamp power.

Abstract: An improved coiled-coil filament for use in an incandescent lamp has a primary coil winding with a substantially uniform spacing between successive coil turns. The primary coil winding is wound around a second mandrel in a manner to provide a main coil body and leg portions extending therefrom. A helical bend is formed between the main coil body and the leg portions thereby allowing that the leg portions extend toward a seal region of the lamp envelope in a substantially parallel relation to each other. Once the main coil body has been set in shape, the first and second mandrels are removed such that the leg portions are disposed in the seal region of the lamp envelope in a spaceless, and optional spudless manner.

Abstract: An interference filter or coating is provided in a predetermined pattern on a lamp envelope. The coating is comprised of alternating layers of high and low index of refraction materials applied to a vitreous outer surface of a lamp envelope. The coating may be geometrically symmetric or asymmetric, continuous or discontinuous with respect to the coating itself or the envelope to which it has been applied. The envelope can be masked prior to deposition of the coating so that removal of the mask leaves the filter in the desired pattern. The preferred process for forming the coating includes forming a boric oxide mask on a portion of the envelope, applying the coating over the mask and removing the coating from masked areas of the envelope by dissolving the mask in an aqueous solution.

Abstract: A lamp-to-light guide coupling arrangement includes an electrodeless high intensity discharge lamp comprising an arc tube with an ionizable fill, and an excitation circuit for electrically exciting the ionizable fill to induce therein a light-producing arc discharge. The coupling arrangement further includes a coupling device comprising a generally tubular, hollow body that has an inlet end for receiving light from the arc discharge and a larger, outlet end. The coupling device further comprises an interiorly directed reflector on a surface of the hollow body for reflecting visible light. Such coupling device is shaped so as to receive light at one solid angle over an area of the inlet end and to transmit light at a smaller solid angle but over a larger area of the outlet end. The coupling device is preferably formed from dielectric material. The reflector preferably comprises a refractory optical interference filter.

Abstract: A compact fluorescent lamp is provided having a generally helically shaped lamp envelope wherein the two end segments of the lamp envelope extend radially inward from the pitch of the helix. The end segment extend into openings formed in a mounting cap member which is essentially dome-shaped at the center portion thereof. The mounting cap member can be constructed of two pieces each of which accepts one of the end segments of the lamp envelope. The mounting cap member is effective for reducing the amount of lamp envelope surface area that must be disposed within the housing of the lamp and is further beneficial in that light generated on the inside surface of the lamp can be reflected outward and more readily escape without losses due to multiple reflections or absorption.

Abstract: An electrodeless fluorescent lamp comprises a sealed lamp vessel containing a fill capable of sustaining a discharge when suitably excited. The fill is excited by an RF electromagnetic field produced by a winding energized by an RF oscillator powered via a rectifier from the mains. To confine the RF field within the vessel a conductive coating FTO is provided inside the vessel. To at least reduce conducted interference a conductive coating A1 is provided on the outside of the vessel G. The coating A1 is electrically coupled (e.g., via 7) to RF ground which may be one side of the mains. An electrically insulative housing covers the coating A1. The housing which extends to a zone of maximum diameter of the vessel may grip the vessel.

Abstract: A beam spreading device for use with a centralized lighting system and which can be applied to emergency vehicle lighting applications achieves a beam pattern light output which is essentially continuous over an output range of plus and minus 45 degrees from a center point. The beam pattern light output also has a predefined height associated therewith. The beam spreading device is constructed so as to have a curved surface which mixes the light travelling therethrough so as to achieve the continuous light output. Side wall surfaces of the beam spreading device provide for total internal reflectance properties of the beam spreading device. In one embodiment, a color wheel can be interposed between the output of optical fibers which transmit the light from the centralized light source to the necessary remote location, and the beam spreading device. The color wheel provides the ability to generate different color light outputs from a single light source.

Abstract: An electrodeless neon discharge light source having a red color light output is provided for use in automotive applications. The light source has a lamp envelope containing a fill of neon gas which, when excited to a discharge state by introduction of an operating signal over a tuned circuit consisting of a resonant capacitor and a ferrite coil, produces a red color light output. A flash control input to a ballast circuit arrangement provides the ability to control the light output using bursts of high frequency sinusoidal energy. The use of the burst signal approach allows for providing varying levels of light intensity output thereby signifying the distinction between braking conditions and an on condition of the tail light. Furthermore, by controlling the rate of flashing of the light source, an indication of a hard braking or emergency condition, could be conveyed.