Gte Products Corporation

Osram Sylvania Inc.

Fred Whitney

Gregory Zaslavsky

Stefan Kotter

Jakob Maya

Walter Peter Lapatovich

Scott J Butler

Valery A Godyak

A Bowman Budinger

Paul A Thibault

Gerhard W Doell

Iosif Sheynberg

Harold H Goss

An apparatus for making a ceramic arc tube for high intensity discharge (HID) lighting applications is provided wherein the arc tube contains a high buffer gas pressure and RF induction heating is used to melt a frit material to form a hermetic seal.

Apparatus for making high buffer gas pressure ceramic arc tube

A ceramic arc tube for high intensity discharge (HID) lighting applications is provided wherein the arc tube contains a high buffer gas pressure. A method and apparatus for making the arc tube are also provided wherein RF induction heating is used to melt a frit material to form a hermetic seal.

High buffer gas pressure ceramic arc tube and method and apparatus for making same

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. The electrodeless lamp assembly further includes at least one electric field applicator for coupling high frequency power to the lamp capsule.

Electrodeless high intensity discharge medical lamp

An arrangement including an electrodeless discharge lamp having a sealed envelope enclosing an ionizable medium capable of emitting radiant energy when subjected to a radio frequency field and a circuit for operating the lamp. The circuit includes an oscillator for generating an output signal at a given radio frequency, an RF amplifier responsive to the oscillator output signal, and an output tank circuit including an induction coil and a capacitor connected in parallel. The RF amplifier includes a pair of semiconductor switches operating in a Class E mode. The induction coil is positioned in close physical proximity to the medium in the envelope for coupling to the medium an electric field having a magnitude sufficient to initiate ionization of the medium and a magnetic field for maintaining the ionization. In a preferred embodiment, the amount of EMI/RFI noise generated in the circuit is reduced by symmetrically driving the induction coil.

Circuit containing symetrically-driven coil for energizing electrodeless

An electronic capacitive ballast circuit for operating a DC discharge lamp, such as a negative glow lamp. The circuit includes a rectifier bridge intercoupling a ballast capacitor and the electrodes of the discharge lamp. The rectifier bridge is separated into two halves allowing the discharge current to flow to opposite ends of the filament of the lamp during alternating half-cycles so that the filament (i.e., cathode) is operated in a double hot spot regime. As a result, lamp maintenance and performance are improved.

Electronic ballast circuit for discharge lamp

A low pressure mercury vapor discharge lamp having a double-tube type discharge vessel consisting of a closed outer glass bulb and an inner glass tube coaxially disposed within the outer bulb. An electrode is disposed in the inner glass tube, while a ring-shaped electrode structure is disposed in the outer envelope outside the inner glass tube. The electrode structure completely surrounds the inner glass tube and includes a pair of lead-in wires and a pair of semicircular electrode sections. Preferably, an inert gas having a pressure within the range of from about 4.0 to 6.0 torr and a quantity of mercury are contained within the lamp. The lamp of the present invention provides a fully diffused discharge without requiring an expensive transistor switching circuit or a permanent magnet to rotate the discharge about the inner tube.

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Salem, MA, United States of America

Fred Whitney