Abstract:
Since the internal electrode of a fluorescent lamp comprises a base portion made from a transparent glass member having substantially the same thermal expansion coefficient as that of a tubular glass bulb and shaped like a pipe or rod and a conductive and transparent film formed on the surface of the base portion, the thermal expansion coefficient of the internal electrode is made equal to that of the tubular glass bulb to prevent damage caused by temperature variations, and the entire internal electrode 4 is transparent so that all the beams from the fluorescent film can be radiated to the outside without being shaded.
Abstract:
An electric gas discharge lamp includes an electrode having a tip portion comprised by a mesh body carrying an emitter material. The mesh body in a favorable embodiment is circular cylindrical and is attached via an electrically conductive thermal isolator to a conductive feed-through, such as a hollow ferrule, extending through a seal of the lamp vessel. As compared to a continuous walled tip portion of similar shape and material, the mesh body has a lower mass and heat capacity, and can therefore be operated at higher temperatures without increasing the temperature of the seal area. The higher operating temperature of the tip portion promotes greater electron emission from the emitter material, and therefore a lower cathode fall. A lower cathode fall enables the lamp to be operated at higher lamp currents for greater light output. The mesh body also has the capability to reduce sputtering from the electrode through improved adhesion of the emitter material to the tip portion and faster attainment of its nominal operating temperature as compared to a smooth continuous walled body. In a favorable embodiment, the lamp is a low pressure discharge lamp having an inside diameter of less than about 5 mm.
Abstract:
A discharge lamp includes a first and a second substrate (12, 14), a cavity disposed in the first substrate (12) or in a portion of the first and a second substrate (12, 14), a first and a second aligned electrode (270, 272) disposed between the first and a second substrate (12, 14) having respective ends extending into the cavity, wherein the first and the second aligned electrode (270, 272) are "T-shaped" when viewed in cross-section. The T-shaped electrodes provide mechanical support that minimizes bending and distortion in the horizontal and vertical directions. The discharge lamp may include a charge of mercury or an inert gas, and may further include a phosphor layer (80).
Abstract:
A discharge device for operation in a gas at a prescribed pressure includes a cathode having a plurality of micro hollows therein, and an anode spaced from the cathode. Each of the micro hollows has dimensions selected to produce a micro hollow discharge at the prescribed pressure. Preferably, each of the micro hollows has a cross-sectional dimension that is on the order of the mean free path of electrons in the gas. Electrical energy is coupled to the cathode and the anode at a voltage and current for producing micro hollow discharges in each of the micro hollows in the cathode. The discharge device may include a discharge chamber for maintaining the prescribed pressure. A dielectric layer may be disposed on the cathode when the spacing between the cathode and the anode is greater than about the mean free path of electrons in the gas. Applications of the discharge device include fluorescent lamps, excimer lamps, flat fluorescent light sources, miniature gas lasers, electron sources and ion sources.
Abstract:
A shrouded pin electrode structure including an elongated pin that extends into the volume of a gas containment structure of an RF excited gas discharge light source and is physically isolated from the discharge gas contained in the volume of the gas containment structure by a shroud structure made for example of a gas impermeable dielectric coating or closed end tube.
Abstract:
A high pressure discharge lamp with a thermally improved anode, as well as a method of making such a lamp, are disclosed. The lamp includes a refractory arc tube with a hermetically sealed arc chamber, a fill in the arc chamber for facilitating light generation, and an anode and a cathode extending into the hermetically sealed arc chamber and being spaced apart from each other. The anode comprises a shank of refractory metal, a cylindrically shaped refractory metal sleeve on a portion of the shank, and an end proximally facing the cathode. The anode end comprises a substantially solid mass of refractory metal, and is integrally joined to both the shank and the metal sleeve to facilitate heat flow from the anode end to the shank and sleeve. The anode end preferably is generally shaped as a hemisphere facing the cathode. The refractory metal sleeve is preferably one or more layers of a helically wound refractory metal wire having an outer diameter more than twice a diameter of the shank.
Abstract:
An electrode for discharge light source which is suitable for discharge display on account of its high reliability and outstanding discharge characteristics attributable to the metal conductor which is formed 1-5 .mu.m thick in the discharge container and also to the film of the material for secondary emission which is formed on the metal conductor from a compound composed of LaB.sub.6 and Ba in an amount of 0.01-20 mol % of LaB.sub.6 or a compound composed of LaB.sub.6, Ba in an amount of 0.01-20 mol % of LaB.sub.6, and Ca in an amount of 0.01-5 mol % of Ba, and is 0.5-2 .mu.m thick so that it is free of pin-holes.
Abstract:
A discharge lamp device includes a tube, and a cathode disposed in said tube and made of a valence-compensated semiconductor ceramic material, or a forcibly reduced semiconductor ceramic material, or a valence-compensated and forcibly reduced semiconductor ceramic material. Since the cathode does not include an electron-emitting material, but uses a semiconductor ceramic material, no vapor is produced by the cathode and also the cathode does not react with mercury vapor filled in the tube. Therefore, the discharge lamp device has improved characteristics such as greater heat resistance, better chemical resistance, and improved discharge characteristics. The discharge lamp device is less costly because the semiconductor ceramic material used as the cathode is inexpensive.
Abstract:
A short-arc discharge lamp includes a combination of electrodes arranged in an opposing relation in a discharge space surrounded by silica glass. An expansion and contraction member made of a shape-memory alloy, which contracts at high temperatures, is fixed on one of the electrodes. A lighting start-up discharge terminal is formed at a free end of the expansion and contraction member. A free end of the lighting start-up discharge terminal is in contact with the other electrode at room temperature but is separated from the other electrode at high temperatures.
Abstract:
A high pressure discharge lamp includes a glass enclosure defining a hermetically sealed discharge space filled with an ionizable gas. A pair of electrodes extend into the discharge space, each electrode having a connection end and a discharge end, between which electrodes, in the operating condition of the lamp, a discharge takes place. A pair of holding portions on opposite sides of the glass enclosure and hold the respective connection ends of the electrodes. Metal lead foils connected to the connection ends are sealed in the holding portions. One or both of the connection ends is shaped, e.g., as a conical frustrum or as a wedge, such that the thickness of its inner end is reduced with respect to the thickness of its outward end. The joining portion of the glass enclosure is internally necked at a position adjacent the reduced thickness portion of the connection end.