US2329124A - Gaseous electrical discharge lamp - Google Patents

Gaseous electrical discharge lamp Download PDF

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Publication number
US2329124A
US2329124A US372273A US37227340A US2329124A US 2329124 A US2329124 A US 2329124A US 372273 A US372273 A US 372273A US 37227340 A US37227340 A US 37227340A US 2329124 A US2329124 A US 2329124A
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US
United States
Prior art keywords
pressure
envelope
discharge
operating
lamp
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Lifetime
Application number
US372273A
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English (en)
Inventor
Lemmers Eugene
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Co
Original Assignee
General Electric Co
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
Application filed by General Electric Co filed Critical General Electric Co
Priority to US372273A priority Critical patent/US2329124A/en
Priority to DEP82836D priority patent/DE748762C/de
Priority to FR878759D priority patent/FR878759A/fr
Priority to BE444348D priority patent/BE444348A/xx
Priority to NL105371A priority patent/NL67953C/xx
Application granted granted Critical
Publication of US2329124A publication Critical patent/US2329124A/en
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
    • H01J61/02—Details
    • H01J61/30—Vessels; Containers
    • H01J61/33—Special shape of cross-section, e.g. for producing cool spot

Definitions

  • My invention relates to gaseous electric discharge lamps and more particularly to a high pressure metal vapor lamphaving an extended illuminating surface of high intrinsic brilliance.
  • gaseous discharge lamps have not been readily adaptable to certain fields of application, such as motion picture projection for ex ample, because such fields generally require a source in which a large amount of light energy is cbncentrated within a small crosses'ectional area if the optical systems of the apparatus involved are to produce clear images.
  • Low pressure gaseous discharge lamps fail in this requirement because their light output perv unit'area of luminous surface is relatively small, 1. e., they have low intrinsic brilliance.
  • high pressure lamps of extremely high intrinsic brilliance such' as the so-called mercury vapor capillary lamps, have been developed. These, however, have not been entirely satisfactory for the reason that the high pressure tends to constrict the arc to a very fine thread and although the arc may have high intrinsic brilliance, it is,
  • a still further object of the invention is to provide a lamp of improved spectral quality.
  • Fig. '1 shows a view, partly in section, of a lamp constructed in accordance with the invention along with a-circuit for operating the same, while Fig. 2 shows across-section taken along the line 2-2 of Fig. 1.
  • the lamp i comprises an envelope 2, preferably of glass or quartz, in which sure may be limited to any desired value.
  • the electrodes 3 3 which-may be of the type generally used in capillary lamps.
  • they may consistv of a central core of thorium within a spiral coil f tungsten wire or they may be formed by a tungsten coil activated by a suitable material such as barium or strontium carbonate. They may even be of the liquid type formed by pools of mercury, for example,
  • the envelope 2 is of flattened shape.
  • the cross-section at the inner surfaces of the envelope may, for example, have dimensions of the order of x .060".
  • Energy for operation of the lamp may be provided by the secondary winding 8 of the leakage reactance transformer 9 which i energized by any suitable source of alternating current power l0 through the primary winding II.
  • the transformer provides the necessary ballast for the lamp.
  • the pressure may be kept at the desired low value, it will generally be necessary that the vapor atmosphere be unsaturated during the operation, i. e., that insufiicient mercury or other metal be present to furnish the amount of vapor which the envelope would normally hold in a vaporized state at the temperature .of operation. Thismay be accomplished by limiting the quantity of material introduced into the envelope to such an extent that it is completely vaporized before the device attains its operating temperature. In this manner the normal operating pres- Of course, if an excess of mercury is used, the pressure may still be kept low by artificial cooling but ing to enlarge it and vice versa. Thus, with high pressures such as obtain in the conventional type of high pressure capillary lamp, the arc will conof atmospheres.
  • centrate in a narrow thread 4 which follows ap- .y the shortest distance between the however, the current strength is iliCiBElScd the arc will be forced to expand in order that it may obey its natural tendency to follow the path of least electrical resistance provided, or" course, that the pressure is prevented pillary lamp.
  • the current necessary to flatten the arc will be roughly proportional to the pressure or to some low power thereof. I am unable at this time to state an exact relationship between the two factors. .With very high'pressures the current density necessary to flatten the arc becomes prohibitive for all practical purposes because with envelope materials presently available, the heat developed tends to melt the envelope. I would estimate the practical upper pressure limit for presently available materials to be not greater than about atmospheres. It thus becomes necessary to reduce the pressure in order to flatten the are at a current within the range of practicality. On the other hand, if too low pressures are resorted to, the light output per unit area is disadvantageously decreased since, as is wellknown, the light output from a gaseous discharge varies with pressure.
  • the upper limit of pressures is dependent largely on the materials available for cathode and envelope fabrication, i. e., the envelope must be made of a material which can withstand heating effect of the high current density necessary to flatten the arc. With the materials now available, the upper limit of pressure is of the order It will be understood, of course, that when new materials capable of withstanding the heat are found, lamps capable of employing the principles of the invention at pressures above the limits specified above may be constructed. In any event, it is thus necessary to strike a compromise between the limiting conditlons of pressure and current if 'a current of practical value is to be used and a useful amount of light obtained.
  • any suitable cooling means as a liquid bath or air blast may be used to aid in maintaining the low pressure. I have found the liquid bath most effective.
  • a gaseous electrical discharge lamp of the high pressure type comprising, an envelope having a flattened transverse cross-section, a pair of electrodes disposed within said envelope and capable of supporting a discharge therein longitudinally of the envelope-a quantity of vaporizable material 'in said envelope suflicient in amount to produce an operating vapor pressure of at least about 0.5 atmosphere, means for sup plying sufiicient-electrical energy to establish said operating pressureand for supplying suificient current between said electrodes to produce a discharge of sufficient density to cause the discharge to substantially fill said cross-section.
  • a gaseous electrical discharge lamp of the high pressure type comprising, an envelope having a flattened transverse cross-section, a pair of electrodes disposed within said envelope and capable of supporting a discharge therein longitudinally'of the envelope, a quantity of vaporizable material in said envelope 7 suflicient in amount to produce an operating vapor pressure of at least about 0.5 atmosphere, means for sup- With a pressure of 2 atmospheres and plying suflicient electrical energy to establish said operating pressure and for supplying suflicient.
  • a gaseous electrical discharge lamp of the about 0.5 atmosphere means for supplying sufficient electrical energy 'to establish said operating pressure'and for supplying sufficient current between said electrodes to produce a discharge of sufilcient density to cause the discharge to substantially fill said cross-section and cooling means for aiding the maintenance of the operating vapor pressure within practical limits, said quantity of vaporizable material being insufficient to produce a saturated vapor atmosphere in said envelope at 1 the normal operating temperature.
  • a gaseous electrical discharge lamp of the high pressure type comprising, an envelope having a flattened transverse cross-section, a pair of,
  • a gaseous electrical dischargelamp of the high pressure type comprising, an envelope having a flattened transverse cross-section, a pair of electrodes disposed within said envelopev and capable of supportinga discharge therein longitudinally of the envelope, a quantity of mercury in said envelope sufficient inamount to produce an operating vapor pressure of the order of 0.5'
  • the method of operating a gaseous electric discharge lamp of the type having a flattened transverse cross-section between electrodes and a high vapor pressure which comprises the steps of maintaining the pressure within a range of the order of 0.5 to 5 atmospheres and passing suflicientcurrent therethrough to cause the discharge to substantially fill said' elongated crosssection.
  • the method of operating a gaseous electric dischargelamp of the type having a flattened transverse cross-section between electrodes and a high vapor pressure which comprises the steps of maintaining the vapor in an unsaturated state at operating. temperature and maintaining the pressure within a range of the order of 0.5 to 5 atmospheres and passing sufiicient current there- "through to cause thedischarge to substantially fill said elongated cross-section.
  • a gaseous electrical discharge lamp of the high pressure type comprising, an envelope having a flattened transverse cross-section, a pair of electrodes disposed within said envelope and capable of supporting a discharge therein longitudinally of the envelope, a quantity of mercury in saidenvelope suflicient in amount'to produce an operating vapor pressure of the order of 0.5
  • the method of operating a mercury vapor electric discharge lamp of the type having a flattened-transverse cross-section between elec-' trodes and a high vapor pressure which comprises'the steps of cooling said lamp to aid in maintaining the pressure within a range of the order of 0.5 to 5 atmospheres and passing a current of density of at least 2.4 amperes per square millimeter therethrough to cause the discharge to substantially fill said elongated cross section.

Landscapes

  • Vessels And Coating Films For Discharge Lamps (AREA)
  • Discharge Lamp (AREA)
US372273A 1940-12-30 1940-12-30 Gaseous electrical discharge lamp Expired - Lifetime US2329124A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US372273A US2329124A (en) 1940-12-30 1940-12-30 Gaseous electrical discharge lamp
DEP82836D DE748762C (de) 1940-12-30 1941-08-02 Elektrische Hochdruckentladungslampe mit flachem Entladungsrohr
FR878759D FR878759A (fr) 1940-12-30 1941-12-30 Perfectionnements aux lampes à décharge
BE444348D BE444348A (de) 1940-12-30 1942-02-02
NL105371A NL67953C (de) 1940-12-30 1942-03-28

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US372273A US2329124A (en) 1940-12-30 1940-12-30 Gaseous electrical discharge lamp

Publications (1)

Publication Number Publication Date
US2329124A true US2329124A (en) 1943-09-07

Family

ID=23467447

Family Applications (1)

Application Number Title Priority Date Filing Date
US372273A Expired - Lifetime US2329124A (en) 1940-12-30 1940-12-30 Gaseous electrical discharge lamp

Country Status (5)

Country Link
US (1) US2329124A (de)
BE (1) BE444348A (de)
DE (1) DE748762C (de)
FR (1) FR878759A (de)
NL (1) NL67953C (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4524306A (en) * 1981-05-13 1985-06-18 Hitachi, Ltd. Extra-high pressure mercury discharge lamp
WO1992012531A1 (en) * 1990-12-31 1992-07-23 Welch Allyn, Inc. Bulb geometry for low power metal halide discharge lamp

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE696505C (de) * 1938-12-01 1940-09-23 Patra Patent Treuhand Elektrische Hochleistungsueberdruckentladungslampe fuer Projektionszwecke

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4524306A (en) * 1981-05-13 1985-06-18 Hitachi, Ltd. Extra-high pressure mercury discharge lamp
WO1992012531A1 (en) * 1990-12-31 1992-07-23 Welch Allyn, Inc. Bulb geometry for low power metal halide discharge lamp

Also Published As

Publication number Publication date
BE444348A (de) 1942-03-31
FR878759A (fr) 1943-01-29
DE748762C (de) 1944-11-09
NL67953C (de) 1951-06-15

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