Osram Sylvania Inc.

Arlene Hecker

George C Wei

David Alan Goodman

Gregory Zaslavsky

Joseph V Lima

Dieter Lang

Helmar Adler

Dana Caldwell

Christopher Scott Nordahl

Scott J Butler

Jeffrey T Neil

Jeffrey William Holt

Lori R Brock

Ernest A Davey, Jr

Karlene J Zuk

Cathy Shaw Trumble

Joanne M Browne

Gregory Zaslvasky

Helmer Adler

Georg C Wei

A single-ended ceramic discharge lamp is described which has an integral optical surface such as a parabolic or elliptical reflector. The single-ended configuration eliminates the need for the mounting structures found in double-ended lamps that can interfere with the light emitted from the lamp, particularly in focused beam applications.

Single-ended ceramic discharge lamp

A high intensity discharge lamp includes an arc tube with a chemical fill, capillaries extended from the arc tube, electrodes fed through the capillaries into the arc tube, and a frit seal that seals the capillaries, where the frit seal includes silica (SiO) in a range of more than 0 wt % to less than 5 wt %, alumina (AlO), and one of dysprosia (DyO) and yttrium oxide (YO). This frit seal material can withstand a higher operating temperature so that the length of the capillaries can be reduced compared to those sealed with conventional frit seal material.

Frit seal material, lamp with frit seal, and method for sealing a high intensity discharge lamp

A sealing composition for ceramic discharge vessels is described. The sealing composition contains about 20 to about 40 mole percent MgO, about 20 to about 45 mole percent YO, and about 20 to about 60 mole percent AlOand has a melting point of less than about 1800&#xb0; C., and preferably from about 1700&#xb0; C. to about 1800&#xb0; C. The sealing composition may be used for making ceramic-to-ceramic or ceramic-to-metal seals in ceramic discharge vessels.

Ceramic discharge vessel having a sealing composition

A method of making an HID lamp and an HID lamp that includes a ceramic envelope with a ceramic capillary, wherein the capillary has an electrode feed-through therein that is sealed inside the capillary by a frit seal that extends inside the capillary a first distance from a distal end of the capillary, and a ceramic heat sink around at least half an external diameter of the capillary, wherein the heat sink is separated from the envelope and from the distal end of the capillary and the heat sink is in thermally conductive contact with the capillary and has an external diameter at least 1.5 times the external diameter of the capillary. In one preferred embodiment, the heat sink does not overlap the frit seal.

HID lamp with frit seal thermal control

A ceramic arc tube having an integral susceptor for RF inductive sealing is described. The integral susceptor in the form of an electrically conductive coating is applied directly to the surface of the arc tube in the seal region. This enables RF heating which is sufficient to melt a frit material and hermetically seal the arc tube. The integral susceptor further provides for a more controlled placement of the seal.

Ceramic arc tube having an integral susceptor

An arc tube for a high intensity discharge lamp comprising a translucent body defining a discharge space and including spaced-apart electrodes; an arc generating and sustaining medium within the discharge space; and a starting aid contained within the discharge space, the starting aid comprising an electrically conductive stripe formed from a mixture of an electrically conductive material and the high temperature material.

Ignition aid for high intensity discharge lamp

A method of producing a ceramic metal halide discharge lamp having a monolithic seal between a sapphire (single crystal alumina) arc tube and a polycrystalline alumina (PCA) end cap. The method includes the steps of providing an arc tube of fully dense sapphire and providing an end cap made of unsintered compressed polycrystalline alumina powder doped with magnesium oxide and yttrium oxide. The end cap is heated until it is presintered to remove organic binder material at a low temperature relative to the sintering temperature. The presintered end cap is placed on an end portion of the arc tube to form a close interface between the two. The presintered end cap and adjacent arc tube are then heated to until the end cap is fully sintered onto the arc tube and the sapphire tube grows into the end cap. A monolithic seal is formed along the interface between the end cap and the arc tube as the sapphire tube grows into the polycrystalline alumina end cap. The yttrium oxide promotes increased growth between sapphire tube and the PCA end cap and is not detrimental to the metal halide chemistry, nor subject to erosion by the metal halide chemistry.

Monolithic seal for a sapphire metal halide lamp

A ceramic metal halide discharge lamp may be made having a monolithic seal between a sapphire arc tube and a polycrystalline alumina cap. The lamp is made by providing an arc tube of fully dense sapphire and providing a cap made of unsintered compressed polycrystalline alumina doped with magnesium oxide and yttrium oxide. The cap is presintered to remove binder material at a low temperature. The presintered cap is placed on an end of the arc tube to form a close interface. The presintered cap and arc tube are then heated to until the cap is fully sintered onto the arc tube and the sapphire tube grows into the cap. A monolithic seal is formed along the interface as the sapphire grows into the polycrystalline alumina.

Ceramic arc tube

A integral starting aid for high intensity discharge lamps is provided wherein the starting aid comprises a conductive, refractory metal nitride stripe which is directly applied to the surface of the ceramic arc tube. Preferably, the starting aid comprises titanium nitride or zirconium nitride and may be mixed a ceramic material to improve translucency.

Integral starting aid for high intensity discharge lamps

A method for making a ceramic body is provided wherein the ceramic components are joined in their green state. The method includes applying heat to the surfaces to be joined to cause a localized melting of the binder. The surfaces are then brought together and joined by alternately applying compression and stretching. The method is particularly advantageous for forming unitary ceramic arc tube bodies for high intensity discharge (HID) lighting applications.

Method of assembling a ceramic body

An optically translucent polycrystalline alumina sintered body consists essentially of alumina, magnesia, terbia and, optionally, yttria. The magnesia is present in an amount of about 0.020 wgt. percent and the terbia is present in an amount of from about 0.005 to 0.060 wgt. percent. The yttria is present in an amount up to about 0.035 wgt. percent.

Translucent polycrystalline alumina and method of making same

An optically transparent polycrystalline alumina sintered body consists essentially of alumina, magnesia, yttria and zirconia. The magnesia is present in an amount of about 0.020 wgt. percent, the yttria is present in an amount of about 0.035 wgt. percent, and the zirconia is present in an amount of about 0.018 wgt. percent. An arc tube for a high pressure sodium lamp made from this composition has greatly increased resistance to sodium loss and concomitant outer jacket darkening, whereby the effective amount of lumen output is increased.

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Beverly, MA, United States of America

Arlene Hecker