摘要:
A metal halide arc discharge lamp comprises an arc tube containing a chemical fill including mercury and metal halides and having first and second electrodes respectively sealed at opposite ends thereof. An outer envelope surrounds the arc tube and has first and second terminals for electrical connection thereto. An electrodeless source of ultraviolet radiation is provided within the outer envelope proximate the arc tube for producing radiation which illuminates the path between the electrodes of the arc tube to decrease the amount of time for generating a gaseous discharge therebetween. The ultraviolet light source includes an envelope of ultraviolet light transmitting material having opposing ends. Portions of the envelope of the ultraviolet light source are capacitively coupled across the electrodes of the arc tube such that the source produces ultraviolet radiation during lamp starting when the first and second terminals of the lamp are energized.
摘要:
A metal halide arc discharge lamp comprises an arc tube containing a chemical fill including mercury and metal halides and having first and second electrodes respectively sealed at opposite ends thereof. An outer envelope surrounds the arc tube and has first and second terminals for electrical connection thereto. A source of ultraviolet radiation is provided within the outer envelope proximate the arc tube for producing radiation which illuminates the path between the electrodes of the arc tube to decrease the amount of time for generating a gaseous discharge therebetween. The ultraviolet light source includes an envelope of ultraviolet light transmitting material containing a fill material and having a single electrode sealed in one end thereof. The single electrode is electrically coupled to one electrode of the arc tube. A portion of the envelope of the ultraviolet light source is capacitively coupled to the other electrode of the arc tube such that the source produces ultraviolet radiation during lamp starting when the first and second terminals of the lamp are energized.
摘要:
An improved metal-halide arc discharge lamp includes an arc tube having a substantially cylindrical body surrounded laterally by a substantially cylindrical heat-conserving sleeve within an evacuated outer envelope. The ratio of the outer radius of the arc tube divided by the inner radius of the sleeve falls within an optimum range of approximately 0.54 to approximately 0.68, and preferably within a range of approximately 0.60 to approximately 0.63. A lamp constructed in accordance with the invention exhibits improved luminous efficacy and color rendering in comparison to prior art counterparts. The improved performance is believed to be attributable to the more nearly isothermal operation of the arc tube for a given wall loading.
摘要:
A metal halide arc discharge lamp having a gaseous fill within the outer envelope and means for suppressing convection currents within such fill; and methods of operating and constructing such lamps. A light-transmissive sleeve or enclosure surrounding the arc tube laterally and about at least one end thereof is so shaped and mounted with respect to the arc tube as to insure that the Rayleigh Number, a quantitative measure of convective flow, in the atmosphere laterally surrounding the arc tube will be less than 5.times.10.sup.4 during operation of the lamp whereby excessive convective heat loss in such lamp will be effectively suppressed.
摘要:
A metal halide arc discharge lamp having a gaseous fill within the outer envelope and means for suppressing convection currents within such fill; and methods of operating and constructing such lamps. A light-transmissive sleeve or enclosure surrounding the arc tube laterally and about at least one end thereof is so shaped and mounted with respect to the arc tube as to insure that the Rayleigh Number, a quantitative measure of convection flow, in the atmosphere laterally surrounding the arc tube will be less than 5.times.10.sup.4 during operation of the lamp whereby excessive convective heat loss in such lamp will be effectively suppressed.
摘要:
A projection lamp comprises a single-ended metal halide arc discharge lamp disposed within a curved reflector and an interference filter disposed in front of the reflector, the filter being highly transmissive of visible light and reflective of radiation for which the metal halide, in molten salt form, is highly absorptive.
摘要:
A low wattage metal halide arc discharge lamp has a press seal at one end thereof with two main electrodes sealed therein. The ratio of the distance from an electrode tip to the nearest arc tube wall over the arc length is greater than 0.4.
摘要:
In a metal halide arc discharge lamp having an arched arc tube with an electrode at each end thereof, each electrode is located about midway between the arc tube lower wall and the axis of the arc tube.
摘要:
An arc tube for horizontal operation and arc discharge lamp employing same wherein the arc tube has devices in each end for suppressing crystalline deposit penetration into the arc tube press seals along the shanks of the main electrodes. Experimental evidence shows that crystalline penetration into a press seal weakens the press seal and is the likely cause of an occasional arc tube burst during lamp operation, a problem well known in the art. In a preferred embodiment, a starting electrode is mounted above the main electrode in each end of the operationally positioned arc tube. So placed, each starting electrode is upstream in the convective flow of the gaseous fill within the arc tube. Each starting electrode may be electrically coupled with the lamp's circuit or electrically isolated therefrom without substantially affecting the starting electrode's ability to suppress crystalline penetration of the press seal about the base of the adjacent main electrode. In a lamp in accordance with the invention, the probability of an arc tube burst during lamp operation has been substantially reduced and, consequently, the need for employment of protective measures or containment devices has been substantially reduced.
摘要:
The present invention is directed to a method for the elimination of end pockets in metal halide arc tube envelopes (or other irregularities) in order to improve the color stability thereof.The present invention is also directed to the improved lamps having reduced or substantially eliminated end pockets.The magnitude of this improvement will increase with decreasing arc tube size, since in smaller arc tubes, the tube ends represent a larger fraction of the overall inner surface of the device.