Abstract:
A circular fluorescent lamp unit comprises a circular glass bulb having a circular outer diameter set within a range of 285 to 310 mm or thereabout. The circular fluorescent lamp unit comprises a tube outer diameter set within a range of 15 to 18 mm or thereabout and an inner surface onto which a fluorescent substance is applied. A discharge medium including a rare gas and a mercury is sealed up in the circular glass bulb. A pair of electrode means is fitted in both end portions of the circular glass bulb so as to be sealed therein. So that discharge occurs in the circular glass bulb by providing the pair of electrode means with a lamp power so that the circular glass bulb lights. The lamp power has a high frequency which is not less than 10 kHz and the lamp power is set within a range of 20 to 40 W or thereabout.
Abstract:
A cold cathode fluorescent discharge tube is provided having, as an anode standing for one of discharge electrodes, a mercury discharge structure comprising a metal sintered body formed by sintering powder of a high melting point metal such as titanium, with mercury combined with the metal sintered body. The mercury discharge structure is so formed as to contain large amount of mercury and is therefore permitted to have a compact shape in order to obtain a requisite amount of mercury. The cold cathode fluorescent discharge tube permits a sufficient amount of mercury to be sealingly incorporated in the interior of the tube without decreasing the ratio of the effective luminescent length to the total length, having suitability to diameter reduction, and can be produced at low cost.
Abstract:
An amalgam is accurately placed and retained in an optimized location in the exhaust tube of an electrodeless SEF lamp for operation at a mercury vapor pressure in the optimum range from approximately four to seven millitorr by forming a dimple in the exhaust tube and using a dose locating member to locate and retain the amalgam on the side of the dimple away from the core of the lamp after filling the lamp. As an alternative, two dimples may be situated on opposite sides of the exhaust tube for performing the same function as, but with less depth than, the single dimple. In another alternative embodiment, first and second dimple configurations are formed in the exhaust tube after tip-off thereof, each dimple configuration including either one or two dimples. The second dimple configuration is spaced apart from the first dimple configuration along the length of the exhaust tube. In this way, the amalgam may be initially positioned farther from the tip-off region, thereby avoiding problems during tipping off of the exhaust tube, such as loss of mercury from the lamp, or quenching of the tip which could cause stress cracks. After tip-off, the second dimple configuration allows for placement of the amalgam closer to, or preferably in contact with, the tip of the sealed exhaust tube, i.e., the coolest location in the exhaust tube.
Abstract:
A cold-cathode fluorescent lamp includes an opposing pair of electrodes in spaced relationship in a tubular glass bulb of which the inner wall surface is coated with fluorescent material, and each of the electrodes is divided into four plate-like electrode members each having mercury and getter preliminarily coated thereon while maintaining a necessary area for each electrode without any contact with the inner wall surface of the tubular glass bulb. The opposite ends of the tubular glass bulb are airtightly sealed with beads through which electricity feeding wires extend for feeding electricity to the electrodes while holding the electrodes in the tubular glass bulb. Two of the four plate-like electrode members are located on one side of each electricity feeding wire, while another two of the same are located on the opposite side of the same. The respective plate-like electrode members are spot-welded to each electricity feeding wire. With this construction, the length of each electrode as measured in the axial direction of the tubular glass bulb can be shortened, and moreover, the length of a non-illuminating part of the cold-cathode fluorescent lamp can also be shortened. Consequently, the whole length of the foregoing type of cold-cathode fluorescent lamp can be shortened. Each of the electricity feeding wires may fully be composed of a Dumet wire.
Abstract:
An amalgam is accurately placed and retained in an optimal location near the cold spot of an electrodeless SEF lamp for operation at a mercury vapor pressure in the optimum range from approximately four to seven millitorr. The amalgam is positioned at the tip of an extended exhaust tube near the apex of the lamp envelope by forming an indentation in the exhaust tube and, in some embodiments, a dose locating member in combination therewith. An evacuation hole is formed below the indentation for evacuation of the lamp envelope, or bulb, during lamp fabrication. In an alternative embodiment, the extension of the exhaust tube is situated perpendicular to the main portion of the tube to allow for lateral adjustment of the position of the amalgam, thereby allowing for even further control of the amalgam operating temperature.
Abstract:
A high pressure sodium lamp including a light permeable arc tube and an electrode extending into the arc tube via a central aperture provided in the arc tube. The electrode is supported in the aperture by means of a glass solder sealing composition. Sodium amalgam is seated in the arc tube and condensed at a corner thereof. To prevent sodium amalgam condensed at the corner of the arc tube from contacting the glass solder filled in the central aperture of the arc tube, sodium amalgam including sodium of 10-30 (wt %) is sealed in the arc tube at a prescribed volume V (mm.sup.3) which substantially satisfies the following relationship: ##EQU1## where D (mm) is the diameter of the arc tube, d (mm) is the diameter of the central aperture, Vo (mm.sup.3) is the volume of the sodium amalgam sealed in the arc tube when the shortest distance between the sodium amalgam condensed at the corner and the glass solder filled in the central aperture is given by ##EQU2## and WL (W) is the lamp power.
Abstract:
A high-efficacy, high power ultraviolet radiation lamp is disclosed. Electrodes are respectively provided at two ends of a discharge tube, and at least a rare gas is sealed in the discharge tube. The discharge tube is curved in a U shape. A reservoir for reserving a radiant material for radiating ultraviolet rays projects from the discharge tube. An isolating section is provided to surround at least the reservoir. The isolating section adjusts the temperature of the reservoir and supplies an appropriate amount of radiant material into the discharge tube.
Abstract:
A mercury capsule for dispensing mercury into an arc discharge lamp comprises an annealed metal member having a predetermined wall thickness and including a generally tubular main body portion containing a predetermined amount of mercury and a sealed end portion adjacent the main body portion. Means for sealing the end portion includes a flattened, generally planar configuration having at least one sealing constriction formed in the end portion. The sealing constriction has a defined cross-sectional thickness relative to the wall thickness and enables containment of the mercury within the capsule below a predetermined elevated temperature. Preferably, the predetermined cross-sectional thickness of the constriction is less than or equal to about two-thirds of the wall thickness of the metal member.
Abstract:
A high pressure sodium vapor lamp for operation at a sodium vapor pressure of at least 60 Torr and in which the start-up interval of variation of lamp operating voltage is reduced by charging the lamp with a ternary amalgam of mercury, sodium and a third metal selected from the group consisting of indium, gallium and tin. The atomic proportion of the third metal exceeds that of the mercury but does not exceed that of the sodium in the amalgam, and the atomic proportion of sodium is at least twice but not over four times that of the mercury.
Abstract:
The life of a low-pressure, hollow cathode lamp with an oxygen/nitrogen filling is extended by the inclusion of MnO.sub.2 which releases oxygen, thereby replenishing oxygen consumption in the lamp.