Gte Products Corporation

Gte Sylvania Incorporated

Osram Sylvania Inc.

James C Morris

William M Keeffe

Zeya K Krasko

Robert L Garrison

P Bruce Newell

Robert J Karlotski

Philip J White

Andre C Bouchard

Edward H Nortrup

Timothy Fohl

John A Scholz

Peter R Gagnon

John Francis Waymouth

Stephen J Leadvaro

Robert S White

Nanu Brates

Ellison H Kirkhuff

John J Lumia

Philippe Verborg

An arc tube comprises a light transmissive body containing an arc generating and sustaining medium and has a press seal formed at one end of said body. The press seal comprises a planar portion separating opposed edges. A first foil is sealed in the planar portion. A lead-in conductor is attached to the foil and extends outside of the body and an electrode is also attached to the foil and extends inside the body. A first cavity is formed on a first of the edges and a second cavity is formed on a second of the edges. A fill is provided in each of the cavities for supporting emission of ultraviolet radiation; and a second foil sealed in the planar portion is attached to the first foil, said second foil having a first end terminating in the first cavity and a second end terminating in the second cavity. A ground plane is provided adjacent the cavities. A high voltage pulse applied to the electrodes, and, thus, the foils, creates a capacitive discharge creating the ultraviolet radiation which aids in starting the lamp in which the arc tube is employed.

Starting aid for metal halide lamps

An ultraviolet starting aid is formed in a metal halide arc discharge lamp by forming a cavity in a press seal portion of an arc tube. An electrode is provided in the cavity which either extends external to the press seal, or the electrode may be a portion of molybdenum ribbon used in the press seal.

Starting source for arc discharge lamps

An apparatus and method for accurately dosing and dispensing mercury. The apparatus includes a reservoir containing mercury and a capillary tube extending from the reservoir of mercury to a dispensing needle and having an inlet located intermediate a pair of remotely located ends. The apparatus adjusts the height of a column of the mercury within the capillary tube and measures the height of the mercury column. In one embodiment, a digital vision system comprising a TV camera and monitor digitizes the image of the mercury column within the capillary tube and automatically determines the height of the column. A source of gas is supplied to the inlet in the capillary tube such that a predetrmined amount of mercury is separated from the mercury column and dispensed from the other one of the remotely located ends of the capillary tube.

Method and apparatus for dosing and dispensing mercury into discharge

An improved metal halide discharge lamp is provided. The improved metal halide includes an arc tube having a pair of electrodes and containing a fill including an inert starting gas, mercury, and metal halides; and an outer envelope enclosing the arc tube. The entire outer surface of the arc tube is coated with a heat reflective material to improve lamp efficiency.

Metal halide lamp having reflective coating on the arc tube

A low wattage metal halide discharge lamp includes an evacuated envelope wherein is disposed a heat loss reducing member having an arc tube therein and means for interrupting the circuit for the current flow which sustains the electrolytic sodium loss process. In one embodiment, the circuit interruption means includes supporting the arc tube and dome sleeve by a supporting rod that is affixed by a metal strap to the glass stem within the lamp. The primary circuit interrupting effect occurring upon the heat loss reducing member being supported about the arc tube in an electrically insulated manner so as to create a high path of resistance back to the power supply. A substantial reduction of sodium loss along with improved color constancy and voltage stability resulted from interruption of the electrolysis circuit.

Low wattage metal halide discharge lamp

An improved metal-halide arc discharge lamp includes an arc tube having a substantially cylindrical body surrounded laterally by a substantially cylindrical heat-conserving sleeve within an evacuated outer envelope. The ratio of the outer radius of the arc tube divided by the inner radius of the sleeve falls within an optimum range of approximately 0.54 to approximately 0.68, and preferably within a range of approximately 0.60 to approximately 0.63. A lamp constructed in accordance with the invention exhibits improved luminous efficacy and color rendering in comparison to prior art counterparts. The improved performance is believed to be attributable to the more nearly isothermal operation of the arc tube for a given wall loading.

Metal-halide lamp having heat redistribution means

The present invention is directed to a method for the elimination of end pockets in metal halide arc tube envelopes (or other irregularities) in order to improve the color stability thereof. The present invention is also directed to the improved lamps having reduced or substantially eliminated end pockets. The magnitude of this improvement will increase with decreasing arc tube size, since in smaller arc tubes, the tube ends represent a larger fraction of the overall inner surface of the device.

Dimpled arc tube having no internal end pockets and a lamp employing same

Method to reduce color temperature variation in metal halide arc tubes

A tungsten-halogen lamp for use in an automobile headlight comprises a tubular sealed glass capsule containing two coiled tungsten filaments for high and low beam operation, respectively. The low beam filament is disposed substantially orthogonal to a vertical plane containing the lamp axis, with the center of that filament length having a predetermined offset from that vertical plane and being disposed at or near the focal point of the reflector. The high beam filament is disposed substantially parallel to the lamp axis on the opposite side of the vertical plane from at least a major portion of the low beam filament. The filaments are spaced apart with the high beam filament lying in a horizontal plane spaced below the low beam filament, and the axis of the high beam filament orthogonally intersects a plane containing in the axis of the low beam filament.

Two-filament lamp for automobile headlight

A circuit for starting and operating an arc lamp includes a full wave rectifier having an input connected to a source of alternating current line voltage and a pair of output terminals having a filter capacitor connected thereacross for providing a source of direct current voltage. Connected to one of the direct current terminals is a resonant charging circuit comprising a controlled rectifier switch, an inductor and a capacitor serially connected in a circuit loop. Another inductor, which may comprise the secondary winding of a starting pulse transformer, is connected between the output of the resonant circuit and one of the supply terminals for the arc lamp to provide the dual function of both averaging filter and lamp ballast. The reference terminal of the direct current source is connected to the other arc lamp supply terminal and through a back swing diode to the output of the resonant circuit. A trigger pulse generator is coupled to the resonant charging circuit for intermittently operating the controlled rectifier switch, and a voltage divider is connected across the direct current source for sensing changes in the line voltage and adjusting the pulse rate of the trigger generator in response thereto. In this manner, once the arc lamp is started and operating, the resonant charging circuit maintains a source of constant power to the arc lamp regardless of line voltage variations. Protective sensing circuitry is also provided for controlling the trigger generator output in the event the line voltage is too low, the load current is too high, or the resonant circuit capacitor has not discharged to zero.

Control circuit providing constant power source

An intrusion alarm system and method is provided which includes one or more sound pulse transmitters that are triggered upon the opening of an entryway, such as a door or window, to produce a high-intensity sound pulse having a decibel level above a predetermined minimum. For example, each transmitter may comprise a percussive photoflash unit in combination with a pyrotechnic device which responds to the radiant output of the fired photoflash unit to emit the intense sound pulse. A centralized detector responds to the sound pulse above a predetermined threshold level to produce an alarm signal. Preferably, the detector comprises an electroacoustical transducer arrangement which provides the dual functions of both sound pulse detection and generation of an audible alarm.

Intrusion alarm system

An electrically fired flash lamp which utilizes a single conductive lead member. The lead protrudes within the lamp's envelope and is covered by a quantity of primer material. A conductive coating (e.g. tin oxide) covers a major portion of the external surface of the envelope and is capacitively coupled through the envelope's wall to the combustible filamentary material (e.g. shredded zirconium) therein. In another embodiment, a second conductive coating is located on the internal surface of the envelope opposite the outer coating and in electrical contact with the filamentary material. Accordingly, both coatings are capacitively coupled when the lamp is electrically fired. A sequentially-activated array of the above lamps is also disclosed.

Single lead electrically-activated flashlamp

An intrusion alarm circuit including a single electroacoustical transducer, such as a diaphragm-supported piezoelectric element, connected to an amplifier in a positive feedback loop configuration. The transducer functions as both a sound pickup and sound generator. When the ambient sound level exceeds a preselected threshold level, the resulting vibration of the transducer generates a voltage which activates the amplifier, whereupon the transducer vibrations are sustained and amplified in the manner of an oscillator, thereby producing an audible alarm.

Audio-detector alarm

Several means are described for providing an electrical coupling path through a protective, insulative layer, e.g. cellulose acetate, located on an electrically activated flash lamp envelope. The function of the path is to interconnect a thin conductive coating positioned on the envelope's external surface under the insulative layer with an electrical contact located externally of the flash lamp and adapted for igniting the lamp.

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Wakefield, MA, United States of America

James C Morris