Abstract: The hot re-strike time of a high wattage (150 W or greater) ceramic discharge metal halide (CDM) lamp is reduced by: (a) increasing the ratio A of the diameter (D2) of the outer bulb (1) to the inner diameter (ID) of the discharge vessel (3); or (b) filling the outer bulb with an inactive gas such as nitrogen, helium, neon, argon, krypton or xenon; or by implementing both (a) and (b). The hot re-strike time can be further reduced by combining (a) and/or (b) with (c), the addition of a getter metal for iodine, such as Sc, Ce or Na, to the discharge vessel (3).

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor® series having power ranges of about 150 W to about 1000 W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gas-tight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gas-tight connection.

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor series having a molybdenum coil wrapped around the discharge vessel and at least a portion of the electrode feed through means, and having power ranges of about 150 W to about 1000 W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gastight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gastight connection.

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor series having a molybdenum coil wrapped around the discharge vessel and at least a portion of the electrode feed through means, and having power ranges of about 150 W to about 1000 W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gastight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gastight connection.

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor® series having power ranges of about 150 W to about 1000 W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gas-tight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gas-tight connection.

Abstract: A metal halide lamp has a ceramic discharge vessel with an inside length L, an inside diameter D, and an aspect ratio L/D of between 3 and 5. The fill gas includes xenon, mercury, sodium halide, and halides of rare earth metals. Hydrogen iodide voltage spikes during start-up are related to product of volume and the cold xenon pressure, which are adjusted to limit the spikes. Voltage crest factor is related to the product of total operating pressure and the square of the inside diameter, which are adjusted to limit the crest factor. The ceramic discharge metal halide (CDM)lamp may have a power rating of 200 W or more and can be used with an existing ballast for a high pressure sodium (HPS) lamp of like power rating.

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor series having a molybdenum coil wrapped around the discharge vessel and at least a portion of the electrode feed through means, and having power ranges of about 150 W to about 1000 W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gastight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gastight connection.

Abstract: The invention relates to a high-pressure discharge lamp of the ceramic metal halide type of the Philips MasterColor® series having power ranges of about 150W to about 1000W. Such lamps are provided with a discharge vessel which encloses a discharge space. The discharge vessel has a ceramic wall and is closed by a ceramic plug. An electrode which is located inside the discharge space is connected to an electric conductor by way of a leadthrough element. The leadthrough element projects through the ceramic plug with a close fit and is connected thereto in a gas-tight manner by way of a sealing ceramic. The leadthrough element has a first part which is formed by a cermet at the area of the gas-tight connection.

Abstract: Discharge lamp includes a ceramic metal halide lamp having a central barrel enclosing a discharge space containing a fill gas and opposed end plugs which receive electrode lead-ins therethrough. A conductive ring is provided around each end plug, which is preferably polycrystalline alumina (PCA). These rings are connected by an antenna on the central barrel and thereby capacitively coupled to the lead-ins. The rings and the antenna are preferably sintered tungsten which is coated on the arc tube in paste form prior to sintering. When a voltage is applied across the electrodes, the resulting electric field causes the PCA to emit UV radiation which stimulates photoelectrons to initiate a discharge in the fill gas.

Abstract: Thin film interference filter consists of alternating first and second layers, the first layers being silica, the second layers being a mixture of tantala and niobia. The filter may be used on a high temperature lamp in an inert atmosphere if the niobia in the mixture is less than 40% by weight. For higher percentages a partial pressure of oxygen has been found to prevent blackening of the layers.

Abstract: A discharge lamp comprises an HPS discharge device within an outer envelope filled with inert gas. A normally nonconductive spark gap device within the outer envelope is connected across conductors used to apply a voltage to the HPS discharge device. The spark gap breaks down when the applied voltage exceeds a certain value to prevent breakdown through the inert gas within the outer envelope.

Abstract: A high pressure sodium discharge reflector lamp having a blown glass outer envelope. The outer envelope contains a rare gas having a fill pressure slightly less than one atmosphere and a pressure at lamp operating temperature of approximately one atmosphere for implosion protection.

Abstract: A lamp stem having integral glass structure for controlling gas flow into the lamp outer envelope of an electric lamp during back-fill. The lamp stem having a protrusion adjacent the stem press through which a conduit connected to the exhaust tube extends with a curved profile. The end portion of the conduit extends in the direction of the stem skirt and defines an acute angle with the exhaust tube. The end portion is angled for directing the gas flow during back-fill away from coated portions of the lamp envelope in which the stem is sealed. The conduit may have a cross-sectional area which increases in the direction of the gas flow so that the conduit functions as a gas diffuser for reducing the velocity of the gas in addition to directing the gas flow in a desired direction. In an alternative embodiment, the conduit terminates adjacent the stem press.