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Matsushita Electric Works Research & Development Labratory

Matsushita Electric Works Research and Development Laboratories Inc

Matsushita Research and Development Laboratories Inc

Matsushita Electric Works R & D Laboratories Inc.

Matsushita Electric Works Research and Development Laboraty Inc.

Edward K Shapiro

Jakob Maya

Oleg A Popov

Robert T Chandler

Jagannathan Ravi

Pradeep Kumar Nandam

Frank D Mellen

Koichi Kobayashi

An electrodeless lamp includes an envelope ( ) containing a fill of discharge gas, a magnetic core t( ), an induction coil ( ) wound around the magnetic core ( ), a driver circuit for supplying an electric current to the induction coil ( ) to operate the electrodeless lamp, a socket ( ) for receiving electrical power supplied to the electrodeless lamp, and a heat conduction means ( ) thermally coupled to the magnetic core ( ) for conducting heat generated in the magnetic core ( ) to the ambient atmosphere to dissipate heat therein, or coupled to the socket ( ) for conducting heat generated in the magnetic core ( ) to the socket to dissipate heat therethrough.

Electrodeless lamp

The present invention comprises a compact electrodeless fluorescent lamp that includes a transparent envelope containing a fill of inert gas along with a vaporizable metal such as mercury. An induction coil is operated by a driver circuit, and is positioned inside of a reentrant cavity in the envelope with an adjacent permeable magnetic field manipulation structure having a shunting surface ending at a shunting surface periphery. A thermally and electrically conductive primary cooling structure is positioned adjacent the magnetic field manipulation structure to extend within the shunting surface periphery while being separated from the induction coil thereby. A further component cooling structure is provided to at least partially enclose the driver circuit connected to the induction coil.

Compact electrodeless fluorescent lamp with improved cooling

An electrodeless fluorescent lamp comprises a closed-loop (&ldquo;tokamak&rdquo;) envelope, two ferrite cores, and an induction coil that is disposed on the envelope walls inside the closed-loop formed by the envelope. The envelope comprises two straight tubes of the same diameter. All coils' turns have essential the same length and are parallel to each other and to the closed-loop axis. Each ferrite core encircles a segment of each the coil's turn and one connecting tube. The lamp can be operated at driving frequencies of 100-600 kHz and lamp powers of 50-250 W. The ferrite core power losses were 6-8 W when the lamp was operated at a frequency of 200-300 kHz and lamp power of 140-150 W. The lamp light output was 12,500 lumen and luminous efficacy was 87 LPW.

High light output electrodeless fluorescent closed-loop lamp

An electrodeless compact fluorescent lamp operated at a frequency from 50 KHz to 1000 KHz and RF power from 10 W to 40 W is described. The lamp includes a bulbous glass envelope ( ) filled with rare gas and metal vapor, reentrant glass cavity ( ), an induction coil ( ) made from Litz wire, a ferrite assembly comprising a ferrite core ( ) and MnZn ferrite disk ( ), a cooling structure comprising a metal (or ceramic) tube ( ) positioned inside the ferrite core ( ) and a metal (or ceramic) unit ( ) that transmits the heat from the cavity and ferrite assembly to the Edison socket ( ), a thermal shield ( ), and a driver and matching network located inside the lamp base ( ). A protective coating ( ) and phosphor coating ( ) are coated on the inner surface of the envelope ( ) and reentrant cavity ( ). The reflective coating ( ) made from alumina is coated on the inner surface of the cavity ( ) and on the outer surface of the envelope bottom ( ). The mercury pressure is controlled in the envelope by the temperature of the amalgam ( ) positioned in the tubulation ( ) or by the temperature of pure mercury located in the cold spot.

High frequency electrodeless compact fluorescent lamp

An electrodeless fluorescent lamp and fixture which operates at the frequency range of 50-1000 KHz and power from 20 to 200 W is disclosed. The lamp includes a bulbous envelope (1) filled with rare gas and metal vapor and a reentrant cavity (5). The inner walls of the envelope are coated with phosphor (2) and a protective coating (3). An induction coil (9), made from multiple strands of wire having very low resistance at frequencies below 1000 KHz, together with a ferrite core (10), having high permeability and low power losses, generates an inductively-coupled plasma in the envelope volume. The plasma generates visible and UV radiation that is converted into visible light by the phosphor coated on the envelope walls. A metallic cylinder (13), placed inside the ferrite core (10), removes the heat generated by the plasma from the coil and ferrite core and redirects the heat to the lamp base and thence to the lamp fixture. The power efficiency of the lamp operated at frequencies 200-300 KHz and its efficacy are the same as those in electrodeless RF lamps operated at frequencies of 2.65 MHz and at 13.56 MHz.

High-frequency electrodeless fluorescent lamp

A compact fluorescent lamp is designed to imitate an incandescent lamp in size, shape and luminosity. The lamp includes a bulbous envelope (14) having an external shape of an incandescent lamp (10) on a standard Edison-type base (11) that enables it to be substituted for standard 60, 75 and 100 W incandescent lamps. A low-pressure fluorescent lamp (18) having a coiled tubular envelope with an outer diameter less than about 7 mm, an inner diameter between about 1 and 5 mm, and a length between about 50 and 100 cm is wound in a coil around the axis of the bulbous envelope (14) and is disposed within the bulbous envelope. The tubular envelope is formed of soft glass and has a fluorescent phosphor coating disposed on the inner surfaces. Electrodes (14) with external electrical contacts are disposed at each end of the envelope. A ballast (12) is disposed within the bulbous envelope. The ballast is electrically connected to the lamp (15), whereby to control current in the fluorescent lamp. A heat shield (17) is disposed between the lamp and the ballast to thermally isolate the lamp from the ballast, whereby heat from the lamp will not adversely affect the ballast.

Compact fluorescent lamp as a retrofit for an incandescent lamp

An electrodeless inductively-coupled fluorescent lamp which operates at ro frequency comprising a bulbous envelope (1) filled with rare gas and metal vapor. A reentrant cavity (4) and an induction coil (6) are disposed in the cavity (4). The inner walls of the envelope (1) and the cavity (4) have a protective coating (3) and a phosphor coating (2). A metal Faraday cylinder (12) welded to the lamp base (13) is disposed between the cavity (4) and the coil (6) to reduce capacitive RF voltage between the coil and the plasma to improve lamp maintenance and remove heat. A tubulation (16) is disposed on the lamp axis to evacuate the envelope (1). The proximal end of the tubulation (16) has an expansion (20) with the volume (23) where the initial capacitive discharge is ignited. The RF coil voltage needed for the ignition of the capacitive discharge in the expansion area (23) is substantially lower than that needed for the ignition of the capacitive discharge in the area (14) along the inner cavity walls (4) to decrease the lamp starting voltage. In one of the embodiments of the present invention the expansion is conically shaped and in another it is cylindrically shaped and is used to generate the inductive plasma to increase the light generation in the top part of the bulb (28) and improve light output through the bulb top surface (27).

Electrodeless inductively-coupled fluorescent lamp with improved cavity

An electrodeless fluorescent lamp containing a fill of a rare gas and mercury and a flag (14) disposed therein at a predetermined location in the lamp for increasing the rate of luminous development in the lamp. The flag (14) includes a pair of spaced-apart metallic foil sections (31) and a metallic mesh substrate (30) disposed between the foil sections (31) whereby to be shielded from ion bombardment of the discharge. A coating (30a) of indium which is adapted to amalgamate with the mercury is disposed on the mesh (30). The sections are joined together by spot-welding (32) to enable migration of mercury into and out of the space between the sections thereby enable the atoms to form an amalgam with the indium and be rapidly released therefrom.

Electrodeless discharge lamp and device for increasing the lamp's

An electrodeless fluorescent lamp and fixture is disclosed which operates radio frequencies and contains a metallic cylinder 9 to suppress capacitive coupling between an induction coil 7 and a plasma in the envelope 1 of the lamp and simultaneously substantially reduce heat in a reentrant cavity 5. The lamp includes a bulbous envelope 1 having a conventional phosphor layer 3 disposed therein. The bulbous envelope 1 contains a suitable ionizable gaseous fill. Upon ionization of the gaseous fill, the phosphor is stimulated to emit visible radiation upon absorption of ultraviolet radiation. The reentrant cavity 5 of the bulbous envelope 1 contains an inducation coil. The cylinder 9 transfers heat from the plasma to the fixture 11 through a base 13, 13a on the envelope 1.

Growing community of inventors

Lexington, MA, United States of America

Edward K Shapiro