Abstract: The invention relates to a gas discharge lamp having a gas discharge tube, which is at least partly surrounded by a transparent protective bulb, the latter having a bursting guard. The protective bulb is designed as a completely closed envelope bulb, which surrounds in vacuum-tight manner the gas discharge tube. The bursting guard also completely envelops the envelope bulb.

Abstract: A metal halide high-pressure discharge lamp has a discharge vessel of comt construction, with a fill of mercury, at least one noble gas, typically argon, and a metal halide, with an excess of halogen. The halogen component of the metal halide is formed by iodine and/or bromine. An average light density in excess of 30 ksb, with a specific arc power of between 400 to 5000 W/cm is obtained over an average lifetime of 250 hours with a color rendering index Ra of at least 85 by utilizing cadmium and lithium as the metal component in the metal halide of the fill. Preferably, holmium also is used as a metal for the metal halide, the fill including between 0.1 and 5 mg cadmium, up to 0.05 mg lithium, and 0.05 to 1 mg holmium in a preferred form, halogen and bromine being present in a mol relation of between 0.5 to 2 within the discharge vessel. The excess halogen may be up to about 35 micromol per cubic centimeter of volume of the discharge vessel.

Abstract: A halogen-metal vapor lamp (1) with its electrodes coming out of the discharge vessel at opposite ends is provided with a highly insulated socket at one end capable of withstanding 30 kV that may have to be applied for warm ignition of the lamp. Contact pins (9,10) of the socket (11) and connection bushings (22,23) of the support (21) into which the socket plugs in, are provided with collars (15,16;25,26) which lengthen the breakdown path length. The fused seal (7) of the lamp through which the high voltage is applied is cemented in a central opening of the socket body and additionally surrounded in part by a collar (17). The other end of the lamp is connected to the socket by an uninsulated rigid conductor in the form of a metal strip to facilitate the dissipation of heat by radiation. A projecting partition (24) at the bottom of the support (21) separates the voltage supply connection to the connection bushings.

Abstract: A-C high-pressure discharge lamp and reflector combination assembly in which the reflector and the lamp are each separately and individually cemented into a base, but are not cemented together. Ventilation openings are formed between the lamp and the reflector in the base, to permit air to pass between the base and the lamp, and between the lamp and the reflector. Preferably, the reflector at the end remote from the base is surrounded with a ceramic end ring, at the inner circumference of which extends a metallic ribbon or strip which has radially extending connecting portions to the electrical terminals of the lamp, placed edgewise with respect to the light radiation to provide for essentially shadowless electrical connection and high-voltage insulation between the lamp terminals. Constructing the lamp as an a-c lamp permits lifetimes in the order of hundreds of hours for a lamp of comparable power and size with respect to d-c high-pressure lamps.