US3252028A - High-output fluorescent lamp having means for maintaining a predetermined mercury vapor pressure during operation - Google Patents

High-output fluorescent lamp having means for maintaining a predetermined mercury vapor pressure during operation Download PDF

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Publication number
US3252028A
US3252028A US119230A US11923061A US3252028A US 3252028 A US3252028 A US 3252028A US 119230 A US119230 A US 119230A US 11923061 A US11923061 A US 11923061A US 3252028 A US3252028 A US 3252028A
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US
United States
Prior art keywords
envelope
lamp
neon
loading
lamps
Prior art date
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Expired - Lifetime
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US119230A
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English (en)
Inventor
Daniel A Larson
Jr Grant W Manning
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Philips North America LLC
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Westinghouse Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to NL280093D priority Critical patent/NL280093A/xx
Application filed by Westinghouse Electric Corp filed Critical Westinghouse Electric Corp
Priority to US119230A priority patent/US3252028A/en
Priority to GB20057/62A priority patent/GB1006100A/en
Priority to FR901687A priority patent/FR1326177A/fr
Priority to DEP1270A priority patent/DE1270176B/de
Application granted granted Critical
Publication of US3252028A publication Critical patent/US3252028A/en
Assigned to NORTH AMERICAN PHILIPS ELECTRIC CORP. reassignment NORTH AMERICAN PHILIPS ELECTRIC CORP. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: WESTINGHOUSE ELECTRIC CORPORATION
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/70—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr
    • H01J61/72—Lamps with low-pressure unconstricted discharge having a cold pressure < 400 Torr having a main light-emitting filling of easily vaporisable metal vapour, e.g. mercury

Definitions

  • high output uorescent lamps which have a much higher loading than lamps of conventional design.
  • the term loading refers to the number of Watts per unit of lamp length.
  • Fluorescent lamps of conventional design having a loading as high as 16 watts per foot are known but are relatively ineicient as compared to lamps having a normal loading of 10 watts per foot and thus have not been widely adopted, at least not in this country.
  • the high output lamps now -being marketed have loadings as high as 25 watts per foot.
  • a conventional fluorescent lamp cannot be converted into a high output lamp simply by increasing the power input and thus increasing its loading. The reason for this is because the lamp elliciency decreases as the current density increases.
  • Various means have been employed to compensate for the drop in eliiciency at high loadings, such as the use of indentations or grooves in the lamp envelope that increase the ion losses to the wall-s, and the use of lighter fill gases such as neon that increases the mobility of the mercury ions-both of which increase the diffusion losses and the electron temperature. This increase is electron temperature, in turn, increases the efficiency with which ultraviolet (UV) radiations'are produced within the discharge and, thus, the lamp eiciency.
  • UV ultraviolet
  • a high output fluorescent lamp must also have a satisfactory lumen maintenance during life.
  • lighter iill gases such as neon for the usual argon lill vhas aggravated the problem of lumen maintenance insofar as sputtering occurs at a much faster rate resulting in a more pronounced blackening of the envelope.
  • the use in the prior art highly-loaded lamps of a T12 (l1/2 inch diameter) bulb with a lighter gas ll has further aggravated the maintenance problem because of the more intense blackening of such relatively small bulbs.
  • a larger T17 (2l/s inch diameter) envelope is employed.
  • the same problem with regard to eliiciency and maintenance prevail.
  • a fluorescent lamp having a fill gas and bulb size such that the operating temperature for optimum UV generation and eiciency is considerably below that heretofore considered standard for fluorescent lamps.
  • v operated at an ambient of 40 3,252,028 Patented May 17, 1966 T17 envelope are combined according to a preferred embodiment of the invention to provide a high output lamp that not only has a higher etiiciency but better lumen maintenance during life than the prior art lamp designs.
  • the operating temperature for optimum mercury vapor concentration is about 35 C. instead of the usual 40-45" 'C.
  • Means for maintaining a region within the lamp that has the aforesaid lower operating temperature is also provided.
  • FIGURE 1 is an elevational view of a high output ll-uorescent lamp that incorporates this invention, a part of the envelope being omitted for convenience of illustration;
  • FIG. 2 is a graph illustrating the relationship between the voltage-versus-current characteristics and the bulb diameter for a plurality of liuorescentlamps of conventional loading and design; f
  • FIG. 3 is a graph illustrating the relationship between the fill gas composition and the relative efliciency and brightness of highly-loaded lamps embodying t-he invention
  • FIG. 4 is a graph illustrating the relationship between the lamp wattage and the fill gas composition of the improved lamps.
  • FIG. 5 is a graph illustrating the relationship 'between the end chamber temperature and the relative efficiency and brightness for a representative lamp incorporating the invention.
  • FIG. 1 there is shown a highly-loaded fluorescent lamp 10 embodying this invention which lamp generally comprises a tubular light-transmitting envelope 12 that is provided at each end with the usual bases 13 and 14.
  • Mount assemblies 15 and 16 are sealed to each end of the envelope and support oppositely disposed thermionic elect-rodes 17 and 18, such as tungsten coils that have been coated with a suitable electron-emissive material such as the well-known mixture of alkaline earth oxides, for example. with phosphor 22 that converts the UV radiation generated Within the discharge into visible light.
  • the envelope also contains the usual charge of mercury 20 and an inert ionizable lill gas.
  • the iill gas in accordance with this invention comprises neon, or a preselected mixture of neon and argon, at'a preselected pressure, as hereinafter disclosed.
  • Suitable cooling means for controlling the mercury vapor pressure is provided, such as heat-deflecting shields 23 and 24 that are held in transverse relation with respect to the lamp axis by the mount assemblies 15 and 16.
  • the shields may be fabricated from a suitable metal such as nickel and are of such diameter that they provide a cooling chamber of predetermined length L at each end of the lamp 10.
  • the character of a mercury-rare gas discharge is such that for a given lamp design and current density the lamp voltage inherently decreases as the diameter of the envelope increases.
  • a T8 lamp has a rating' of about volts (as shown by curve a rating of about 95 volts (curve 28), a rating of about 65 volts (curve 30). which these curves were obtained were Ventional loading and design filled with 26), a T12 lamp 2 mm.
  • the inner surface of the envelope is coatedand a T17 lamp The lamps from lamps of con-- C. On the basis of such 3 data it was the general belief heretofore that T17 tubing was not desirable or practical for use in making highlyloaded lamps because of the low voltage gradient and low eliiciency which would normally result.
  • T17 high output lamp of superior maintenancev and efliicency can be obtained in accordance with this invention by using afilling of 100% neon, or a mixture of neon and argon which contains at least 80% neon, and a ill pressure of between about 0.5 and 2.5 m'm. of mercury, and preferably from about 1.5 to 2.5 mm.
  • the lill pressure should be ⁇ about 2 mm.
  • the T17 lamp 10 of the present invention operates most eiiiciently when there is a region within the lamp that has a normal operating ternperature of from about 30 to 35 C.
  • the required lower operating temperature for optimum eiiiciency is obtained by correlating the diameter D of the envelope l2 and the length L of the cooling end chamber.
  • D the diameter of the envelope l2
  • L the length of the cooling end chamber.
  • the brightness or light output of the aforesaid T17 lamp decreases as higher concentrations of argon are added to the neon lill gas.
  • the lill gas, according- 1y consists of 100% neon, or a mixture of neon and argon wherein neon constitutes at least 80%y of the mixture, .and preferably from about 85 to 95% thereof.
  • the lamps on which these curves are based were 100 Watt T17 lamps 4 foot long having an end chamber temperature of approximately 35 C. and a lill pressure of 2 mm. Points A and B designate the eliiciency and brightness,
  • the wattage of a T17 lamp of the same design as described above decreases rather rapidly from a maximum when 100% neon is used as the fill gas and then begins to level out when the iil-l gas comprises a 9/1 mixture of neon and argon. With respect to maximum wattage and brightness, optimum results will accordingly be realized with 100% neon, or a mixture of neon and argon wherein the argon is present in only very small amounts.
  • the light output and eiciency as well as the power factor of a 4 foot T17 lamp having an 87% neon-13% argon till are compared below in Table I with .
  • the lamps had end chambers at both ends 7 centimeters long and were provided with heat shields behind the electrodes.
  • T17 highlyloaded fluorescent lamp having the specific designA features hereinbcfore described is superior in both efficiency and lumen maintenance in comparison to conventional highly-loaded lamps having bulbs of smaller diameter.
  • thermoelectric cooling can be employed in the manner disclosed in U.S. Patent No. 2,932,753.
  • a low-pressure electric discharge lamp adapted to be operated at a predetermined wattage loading and comprising; a tubular radiation-transmitting envelope containing a pair of spaced electrodes, an ionizable medium within said envelope consisting of mercury and a till gas selected from the group consisting of neon and a mixture of neon and argon wherein neon constitutes at least about 80% of the mixture, the pressure of said iill gas being from about ⁇ 0.5 to 2.5mm., and means associated with said lamp for providing a cool region therein, the diameter of said tubular envelope at said cool region being so correlated relative to the cooling ability of said cooling means that the latter provides a location Within said lamp that has a temperature of from about 30 to 35 C. when the lamp is operated at said loading.
  • a high-output low-pressure discharge lamp comprising; a tubular radiation-transmitting envelope having a diameter greater than 11/2 inches, a thermionic electrode at each end of said envelope, a charge of mercury and an ionizable till gas sealed within said envelope, said ll gas comprising essentially neon at from about 1.5 to 2.5 mm. pressure, and means integral with said lamp providing a cooling chamber therein, said lamp a predetermined wattage rating and the dimensions of said cooling chamber and the diameter of said envelope being so correlated that there is provided within said chamber a region having a temperature of from about 30 to 35 C. when the lamp is operated at its rated wattage.
  • a fluorescent lamp adapted to be operated at a loading in excess of 16 watts per foot and comprising; a tubular envelope having a diameter of approximately 2% inches, a phosphor coating on the inner surface of said envelope, a thermionic electrode at each end of said envelope, a contained charge of mercury and an inert ionizable fill gas, said fill gas comprising essentially neon at from about 1.5 to 2.5 mm. pressure, and a cooling chamber at one end of said envelope, the length of said cooling chamber being so correlated with respect to the envelope diameter that there is provided within said chamber a region that has a temperature of from about 30l to 35 C.
  • a low pressure electric discharge lamp adapted for operation at a predetermined wattage loading and comprising; a radiation-transmitting'envelope containing' a pair of spaced electrodes and a predetermined quantity of mercury, an ionizable lill ga-s including at least 80% neon sealed within said envelope, the pressure of said fill gas being from about 0.5 to 2.5 mm., and means adapted in conjunction with the cooling effect produced by the size of said envelope to provide a cool region within said envelope that has a temperature between about 30 and 35 C. when the lamp is operated at said wattage loading.
  • a uorescent lamp adapted for operation at a loading greater than 16 watts per foot comprising; a tubular envelope having a diameter of approximately 2% inches, a thermionic electrode at each end of said envelope, a predetermined quantity of mercury and an ionizable ll gas comprising neon containing up to 20% argon sealed within said envelope, the pressure of said ll gas being from about 0.5 to 2.5 mm., and a yheat-deflecting shield located between one of said electrodes and the proximate end of said envelope at a point such that it denes, t0- gether with the encircling end portion of said envelope, a cooling chamber that is approximately 7 centimeters long and 2% inches in diameter and is adapted by virtue of its size to provide a region within said envelope that has a temperature of from about 30 to 35 C. when the lamp is operated at said loading.
  • a fluorescent lamp adapted for operation at a loading greater than 16 watts per foot comprising; a tubular envelope having a diameter of approximately 21/8 inches, a thermionic electrode supported by a mount assembly at each end of said envelope, a predetermined quantity of mercury and an ionizable ll gas comprising at least about neon at a pressure of about 2 millimeters sealed within said envelope, and a heat-detlecting shield on one of said mount assemblies and supported thereby in transverse relation with respect to the longitudinal axis of said envelope at a point located between the proximate electrode and the end wall of the envelope such that it defines, together with the encircling end portion of said envelope, a cooling chamber that is approximately 7 centimeters long and 21/8 inches in diameter and is adapted by region within said envelope that has a temperature of from about 30 to 35 C. when the lamp is operated at said loading.

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  • Discharge Lamp (AREA)
US119230A 1961-06-23 1961-06-23 High-output fluorescent lamp having means for maintaining a predetermined mercury vapor pressure during operation Expired - Lifetime US3252028A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
NL280093D NL280093A (en, 2012) 1961-06-23
US119230A US3252028A (en) 1961-06-23 1961-06-23 High-output fluorescent lamp having means for maintaining a predetermined mercury vapor pressure during operation
GB20057/62A GB1006100A (en) 1961-06-23 1962-05-24 Electric fluorescent lamp
FR901687A FR1326177A (fr) 1961-06-23 1962-06-22 Dispositif électrique à décharge
DEP1270A DE1270176B (de) 1961-06-23 1962-06-22 Niederdruck-Quecksilberdampf-Leuchtstofflampe

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US119230A US3252028A (en) 1961-06-23 1961-06-23 High-output fluorescent lamp having means for maintaining a predetermined mercury vapor pressure during operation

Publications (1)

Publication Number Publication Date
US3252028A true US3252028A (en) 1966-05-17

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US (1) US3252028A (en, 2012)
DE (1) DE1270176B (en, 2012)
GB (1) GB1006100A (en, 2012)
NL (1) NL280093A (en, 2012)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3806761A (en) * 1971-08-23 1974-04-23 Owens Illinois Inc Gas discharge device with improved memory margin
WO2012136510A1 (de) * 2011-04-04 2012-10-11 Osram Ag Entladungslampe, insbesondere quecksilber-niederdruckentladungslampe, sowie verfahren zum herstellen einer entladungslampe

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2906905A (en) * 1956-09-27 1959-09-29 Duro Test Corp Fluorescent lamp
US2930919A (en) * 1959-01-15 1960-03-29 Westinghouse Electric Corp Discharge device
US2946909A (en) * 1959-03-30 1960-07-26 Westinghouse Electric Corp Discharge device
US2961566A (en) * 1958-06-18 1960-11-22 Sylvania Electric Prod Fluorescent lamp
GB863467A (en) * 1957-05-21 1961-03-22 Gen Electric Co Ltd Improvements in or relating to low pressure electric discharge lamps
GB863468A (en) * 1957-09-16 1961-03-22 Gen Electric Co Ltd Improvements in or relating to low pressure electric discharge lamps

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE558655A (en, 2012) * 1956-06-27
GB835183A (en) * 1957-05-07 1960-05-18 Philips Electrical Ind Ltd Improvements in or relating to low-pressure mercury vapour discharge tubes
GB854388A (en) * 1958-01-06 1960-11-16 Gen Electric Co Ltd Improvements in or relating to low pressure mercury vapour electric discharge lamps
NL246040A (en, 2012) * 1958-12-06

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2906905A (en) * 1956-09-27 1959-09-29 Duro Test Corp Fluorescent lamp
GB863467A (en) * 1957-05-21 1961-03-22 Gen Electric Co Ltd Improvements in or relating to low pressure electric discharge lamps
GB863468A (en) * 1957-09-16 1961-03-22 Gen Electric Co Ltd Improvements in or relating to low pressure electric discharge lamps
US2961566A (en) * 1958-06-18 1960-11-22 Sylvania Electric Prod Fluorescent lamp
US2930919A (en) * 1959-01-15 1960-03-29 Westinghouse Electric Corp Discharge device
US2946909A (en) * 1959-03-30 1960-07-26 Westinghouse Electric Corp Discharge device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3806761A (en) * 1971-08-23 1974-04-23 Owens Illinois Inc Gas discharge device with improved memory margin
WO2012136510A1 (de) * 2011-04-04 2012-10-11 Osram Ag Entladungslampe, insbesondere quecksilber-niederdruckentladungslampe, sowie verfahren zum herstellen einer entladungslampe
CN103460333A (zh) * 2011-04-04 2013-12-18 欧司朗股份有限公司 放电灯、尤其是低压汞放电灯以及用于制造放电灯的方法

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Publication number Publication date
DE1270176B (de) 1968-06-12
NL280093A (en, 2012)
GB1006100A (en) 1965-09-29

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Owner name: NORTH AMERICAN PHILIPS ELECTRIC CORP.

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:WESTINGHOUSE ELECTRIC CORPORATION;REEL/FRAME:004113/0393

Effective date: 19830316