Патент USA US2118452код для вставки
May 24, 1938. C. J_ LE BEL 2,118,452 ELECTRIC LAMP Original Filed Aug. 14, 1929 INVENTQOR _ . CLARENCE J £5551. ‘. Br QM Arrow/5r 2,118,452 Patented May 24, 1938 UNITED“ STATES ‘PATENT OFFICE 2,118,452 ELECTRIC LAMP Clarence J. Le Bel, New York, N. Y., assignor to Raytheon Manufacturing Company, Newton, Masa, a corporation of Delaware Original application August 14, 1929, Serial No. _ 385,707. Divided and this application January 28, 1935, Serial No. 3,689 5 Claims. (Cl. 176-424) This invention relates to electric lamps and particularly to a lamp which will radiate a sub stantial portion of its energy in a predetermined portion of the spectrum. The lamp of this inven 5 tion is characterized by an extraordinary high case of mercury of about 2537 Angstrom units. By varying the pressure of the mercury within narrow limits, this percentage may be reduced somewhat as the energy goes into other wave - lengths. v Apparently some obscure resonance phenomenon is involved in which rare gas par-V output of energy lying in the ultra-violet portion ticles freely interact with mercury particles to of the spectrum. transfer substantially all energy to the latter, and cause it to emit as described. It is possible that , A lamp of this character has great utility in many ?elds. Thus for sterilizing and antiseptic purposes, such a lamp is very eiiicient. Further more, many chemical reactions, especially obscure organic reactions such as are involved in the tan ning of leather, treating of foods and the like, are greatly accelerated by ultra-violet light. For purposes such as these it has been found that only a comparatively narrow portion of the spectrum in the ultra-violet region is useful, and any of the radiant energy outside of this spectrum is therefore wasted. While devices such as mercury arcs in quartz containers are generators of sub stantially powerful ultra-violet rays, their radi ant energy is nevertheless distributed over a con siderable spectrum in this region with a resultant loss of e?iciency. some unstable compound of mercury and rare 10 gas is formed which emits its characteristic radiation. The radiation emitted will in general be one of the prominent lines of the substance having the lower ionization potential, in this in 15 stance mercury. By varying the mercury pressure over the wider limits, as from 1 to 20 microns, it is possible to ionize both the gas and the vapor, and change the color of the resulting light. In fact it is pos sible to go from the pure color of the gas to the 20 pure color of mercury through the combination of the two colors by properly adjusting the mer cury vapor pressure. In this latter case, however, the lamp does not emit as great a portion of its energy in the narrow region of the ultra-violet An object of this invention is to devise a lamp ' spectrum as is true when the mercury pressure in which radiant energy in a certain portion of the ultra-violet spectrum is generated in a much more efficient manner than has previously been the case. A further object is to devise a lamp 30 which will be simple and cheap. . I have discovered that a metal vaporasuch as mercury, and an inert gas,‘ such as argon or neon, at certain pressures when carrying a discharge, exhibit a remarkable phenomenon. Under oper 35 ating conditions the pressure of either one of the rare gases may be between 1 and 8 mm. while the pressure of the mercury must be between 1 and 8 microns. The pressure of the rare gas is not very critical, and may be varied over substantially wide limits. It is, however, necessary to main tain the mercury pressure within critical limits. This may be done by either having the neces sary amount of cooling surface in the tube or by arti?cially cooling the tube so that the desired pressure is maintained. Sodium or other easily vaporizable metals may also be used instead of mercury, while a compara tively inert gas like nitrogen may be used instead of neon. In general the gas should have a high ionization potential. When a lamp with such a mixture of gas is energized so that the gas therein becomes ionized, Irhave discovered that as much as 65% of the total radiant energy is emitted in the form of 55 ultra-violet light having a wave length'in the is maintained within smaller limits. Referring to the drawing, the ?gure shows an induction lamp drawn to full size. ' In the ?gure is shown in true’ form, at sub 30 stantially full size, an electrodeless induction lamp comprising a tubular portion Hi and bulb H2. Either or both may be made of material transparent to the ultra-violet rays generated. A coil H3 energized by a suitable source of high 35 frequency, such as an oscillator H4, encircles bulb H2 and energizes the lamp. After the tube has thus been constructed, it is treated in the customary manner to remove all occluded gases, and exhausted to a high vacuum. 40 A small drop of mercury vapor, indicated by M, may be introduced within the container. In addition, a quantity of argon or neon may be in troduced so that at the operating temperature of the tube, the pressure will preferably be within the limits previously speci?ed. When the tube is ?rst started, much of the discharge is carried by the rare gas. The discharge, however, warms the mercury so that its pressure becomes su?lcient for it to partake of the discharge. Within a very 50 short space of time the lamp begins to function as a generator of ultra-violet rays. For example, in a lamp embodying my invention and containing neon at about 4 mm. and mercury ‘ at about 2 microns, a discharge resulted in a very 55 2 2,118,452 powerful emission of ultra-violet in a region of the spectrum below 2900 Angstrom units. A major portion of this energy was concentrated in the 2537 line. During the operation of this ture, a container having a gas and a vaporizable material located therein, a coil surrounding the major portion of said container, said coil being lamp, the current and pressure within the lamp sage of an electric current through the same, to could be adjusted so that practically the greatest portion of the energy was concentrated in the 2537 line. This application is a division of my co-pending application, Serial No. 385,707 ?led August 14, 1929. - ' What is claimed is: 1. As a new and improved article of manufac ture, a container, an induction coil passing 15 around a major portion of the wall of said con tainer, a medium located within said container and adapted to become excited into luminescence by the passage of an alternating current through said induction coil, so as to produce an arc of 20 predetermined dimensions within said container, a minor portion of the wall of said container be ing suf?ciently spaced from said arc so that the temperature of said spaced part of the wall re mains sufficiently low to prevent the pressure 25 within said container from exceeding a predeter _ mined. limit. 2. As a new and improved article of manufac ture, a container having therein a gas and mer cury, said container having a spherical portion 30 of relatively large volume, and a coil substantially surrounding said spherical portion so that said spherical portion is directly with the ?eld of said coil, said spherical portion having an integral extension which is beyond the ?eld of said coil 35 and which has a smaller volume than said spheri cal portion. - 3. As a new and improved article of manufac adapted, when 'the same is energized by the pas~ vaporize said material and to cause said gas and said vaporized material to emit light, said con tainer having a minor portion oi.’ the wall thereof spaced from the zone of direct luminescence. 4. As a new and improved article of manufac 10 ture, a container having a gas and a vaporizable material located therein, a coil surrounding the major portion of said container, said coil being adapted, when the same is energized by the pas~ sage of an electric current through the same, to 15 vaporize said material and to cause saidgas and said vaporized material to emit light, said con~ tainer having a condensing chamber integral therewith and sharply de?ned from that portion ‘of the container which is surrounded by said 20 coil, said condensing chamber being beyond the zone of direct luminescence. 5. A method of’ producing light which consists in exciting into luminescence a gas which is lo cated within an enclosed chamber and also ex citing into luminescence a vapor which is located within said enclosed chamber, so as to produce a de?nite zone of direct luminescence, and allowing a part of said container which is beyond said ‘zone to remain relatively cool in order to form a con densing chamber for said vapor, the volume of said condensing chamber being smaller than the volume of said zone, said gas and vapor being ex cited into luminescence by an electro-magnetic ?eld which is produced external to said con tainer. . CLARENCE J. LE BEL.