A high-pressure metal-vapor discharge lamp is formed by enclosing scandium-halide, preferably scandium-iodide (ScI3) in the amount of 1.80 x 10 7 to 9.27 x 10 6 gram mol/cc of confined gas, and at least 3.1 times said halide quantity in atomic ratio of free (metal) scandium, together with some mercury as a buffer gas, inside a translucent alumina tube. Such discharge lamp can maintain a luminous efficiency of over 70 lumen/Watt and a general color-rendering index of over 70 for a period in excess of 6,000 hours, and thus, it is very useful as a general lighting source.

High pressure metal vapor discharge lamp

A compact fluorescent lamp has an outer envelope in which there is supported a capsule containing a mercury-free fill comprised of aluminum trichloride. The fill is energized to produce a plasma discharge which emits ultraviolet and visible radiation. Phosphor, in the form of a particulate layer or a gas, converts the ultraviolet into visible light. The lamp may contain electrodes or be electrodeless. In the electrodeless embodiment RF energy may be capacitively or inductively coupled to the fill.

Compact mercury-free fluorescent lamp

An ultraviolet light source includes a volume filled with a dose of AlCl3 and an inert gas. No mercury is used. During electrical discharge excited states of AlCl3, AlCl2, and AlCl emit light, with AlCl having a broad ultraviolet emission peaking at about 261.4 nm. The source may be energized with or without internal electrode. Phosphors may be employed to convert the ultraviolet to visible light. The lamp's envelope may be aluminosilicate coated quartz.

Mercury-free discharge lamp

A fluorescent lamp is described in which spontaneous excimer UV emission in an inner tube results from reacting an inert gas molecule with a halide molecule in the excited state. The UV emission travels through the inner tube envelope to an outer tube and is absorbed by a fluorescent material, i.e., phosphor, to produce visible light which passes through the outer tube envelope. The halide may be supplied by metal halide pellets or liquid droplets, which when heated by an initial discharge through an inert gas, produces metal halide vapors which dissociate and combine with the inert gas (Xe, Ar, Ne, Kr) in the excited state and result in UV excimer emission.

Fluorescent light source excited by excimer emission

A metal-halide discharge lamp for photooptical purposes has a small electe spacing of less than 15 mm, preferably 2-8 mm, to provide an essentially pin-point light source, and a fill which contains AlI 3 in an amount between 0.1 and 4.5 mg/cm 3 . Other filling components may in particular be halides of mercury, indium, thallium or cesium; up to 2 mg/cm 3 of AlBr may be added. The lamp is particularly adapted for combination with a, preferably parabolic, reflector.

Metal-halide discharge lamp for photooptical purposes

A metal halide high intensity lamp containing A1C13 and providing a continuous spectrum. Excess aluminum in the filling gives thermodynamic stability against attack of the tungsten electrodes and other lamp metals by chlorine, and an alumina envelope is used which does not react with A1C13. The filling also preferably contains aluminum tri-iodide, mercury for a buffer gas, and an inert gas to facilitate starting.

Speros Dimitrios M

Papers

Aluminum chloride discharge lamp