Abstract: 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.

Abstract: 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 (SiO2) in a range of more than 0 wt % to less than 5 wt %, alumina (Al2O3), and one of dysprosia (Dy2O3) and yttrium oxide (Y2O3). 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.

Abstract: 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 Y2O3, and about 20 to about 60 mole percent Al2O3 and has a melting point of less than about 1800° C., and preferably from about 1700° C. to about 1800° C. The sealing composition may be used for making ceramic-to-ceramic or ceramic-to-metal seals in ceramic discharge vessels.

Abstract: 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.

Abstract: A mercury-free discharge lamp includes a hollow cylindrical body, two capillaries entirely inside the body and hermetically sealed to the body, each with a respective electrode therein, where the capillaries are separated from each other inside the body by a gap that is a discharge chamber of the discharge lamp, and where each of the electrodes has an interior end exposed inside the discharge chamber and an exterior end extending beyond a respective end of the body. A pair of frit seals seal respective electrode exterior ends to respective ones of the capillaries. The discharge chamber preferably includes a mercury-free metal halide salt fill that is 10 to 54.5 wt % NaI, 6.6 to 15 wt % DyI3, 6.7 to 15 wt % HoI3, 6.3 to 15 wt % TmI3, 7.2 to 12 wt % TlI, and 14.5 to 40.7 wt % CaI2.

Abstract: 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 (SiO2) in a range of more than 0 wt % to less than 5 wt %, alumina (Al2O3), and one of dysprosia (Dy2O3) and yttrium oxide (Y2O3). 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.

Abstract: 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.

Abstract: 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 Y2O3, and about 20 to about 60 mole percent Al2O3 and has a melting point of less than about 1800° C., and preferably from about 1700° C. to about 1800° C. The sealing composition may be used for making ceramic-to-ceramic or ceramic-to-metal seals in ceramic discharge vessels.

Abstract: 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.

Abstract: 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.

Abstract: A method of bonding two ceramic parts to each other includes the steps of preparing a water-based slurry from Al2O3 powder and Y(NO3)3 solution in amounts that yield a eutectic compound of Al2O3 and Y2O3 when heated, placing the slurry in liquid, solid or gaseous form in direct contact with two ceramic parts that are to be bonded to each other, and heating the slurry to a temperature that bonds the two ceramic parts to each other. The method is particularly useful to join two ceramic parts where one is comprised of polycrystalline alumina and the other is comprised of one of single crystal alumina and polycrystalline alumina, such as an arc discharge vessel for a high intensity discharge lamp.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A ceramic discharge lamp, and method of operating same, is provided which contains a cavity between a clear sapphire tube and a PCA cap. During lamp operation, the cavity holds the molten salts to act as a constant temperature reservoir of the molten salts. By manipulating the shape of the cap, for example the curvature of the internal dome, or by building in an offsetting lip, the volume of the cavity can be controlled. By adjusting the thickness of the adjacent cap walls, or by the addition of exterior heat sinking or radiating features on the cap, the temperature of the salt reservoir can be further controlled. The reservoir facilitates providing materials for the plasma at a constant pressure, but without letting the fill condensate flow over and coat the light emitting portions of the clear sapphire transmission cavity wall.

Abstract: 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.