Patent ID: 6483237
Filing Date: 2002-11-19
Classification: H01J

Abstract:
A high intensity discharge lamp, comprising:(a) a lamp bulb envelope composed of single crystal sapphire tubing, the envelope having a tubular burst pressure of at least 4,500 psi at 1,400Â° C. and a maximum tensile strength of 56,000 psi at 1,400Â° C., the lamp bulb envelope being substantially cylindrical and having an inner diameter of between 1 mm and 25 mm and an outer diameter of at least 2 mm; (b) a plurality of end plugs composed of one of polycrystalline alumina and single crystal sapphire, the end plugs being situated at opposite ends of the lamp bulb envelope; (c) first and second electrodes extending through the end plugs so that at least a portion of each of the first and second electrodes is situated within the lamp bulb envelope; (d) a seal sealing each of the end plugs to an inside wall of the corresponding end of the lamp bulb envelope; and (e) a fill situated within the lamp bulb envelope, wherein a voltage is applied to the first and second electrodes to generate an arc plasma therebetween, the voltage being provided by a power supply operating in a continuous non-flash mode, and wherein the arc plasma emits a visible radiation spectrum between 400 nm and 700 nm with a color temperature between 4,000Â° K and 9,000Â° K.