US3875454A - Low-pressure mercury vapour discharge lamp and method of manufacturing said lamp - Google Patents

Low-pressure mercury vapour discharge lamp and method of manufacturing said lamp Download PDF

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Publication number
US3875454A
US3875454A US412606A US41260673A US3875454A US 3875454 A US3875454 A US 3875454A US 412606 A US412606 A US 412606A US 41260673 A US41260673 A US 41260673A US 3875454 A US3875454 A US 3875454A
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US
United States
Prior art keywords
coating
lamp
pressure mercury
low
tin oxide
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
US412606A
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English (en)
Inventor
Der Wolf Rein Willemse Van
Vette Thomas Hendrik De
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.)
US Philips Corp
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US Philips 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
Application filed by US Philips Corp filed Critical US Philips Corp
Priority to US05/516,633 priority Critical patent/US3984589A/en
Application granted granted Critical
Publication of US3875454A publication Critical patent/US3875454A/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
    • H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/38—Devices for influencing the colour or wavelength of the light
    • H01J61/42—Devices for influencing the colour or wavelength of the light by transforming the wavelength of the light by luminescence
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J61/00—Gas-discharge or vapour-discharge lamps
    • H01J61/02—Details
    • H01J61/38—Devices for influencing the colour or wavelength of the light
    • H01J61/42—Devices for influencing the colour or wavelength of the light by transforming the wavelength of the light by luminescence
    • H01J61/46—Devices characterised by the binder or other non-luminescent constituent of the luminescent material, e.g. for obtaining desired pouring or drying properties

Definitions

  • the number of operating hours after which the radiation absorption becomes inadmissible due to the grey discoloration and the lamp thus has to be replaced is firstly dependent on the current density in the lamp, i.e. the number of mA/sq.cm of the cross-section of the discharge space. Furthermore, as regards the grey discoloration, it is a great difference whether the wall of the lamp is bare or is coated with a luminescent coating. In a bare lamp having a bare wall the grey discoloration, both at high and at low current densities, i.e.
  • an apertured part of the glass wall extending longitudinally is not coated with a luminescent material.
  • S-lamp a luminescent coating
  • the glass in the aperture is directly exposed to the mercury discharge and a very strong grey discoloration occurs after a very short time at that area especially when the current density in the discharge is chosen to be high so as to obtain an intensive radiation.
  • a low-pressure mercury vapour discharge lamp according to the invention having a glass envelope whose inner side has a luminescent coating and a transparent metal oxide coating located between this coating and the wall is characterized in that the metal oxide coating consists of tin oxide and has a resistance per square of at least 10,000 Ohm.
  • connection resistance per square of the tin oxide coating is understood to means the resistance measured between 2 strip-shaped parallel electrodes of 1 cm length pressed on the tin oxide coating and being spaced 1 cm apart.
  • the resistance per square of the tin oxide coating must be higher than 10,000 Ohm because otherwise the protective coating is conducting in such a manner that it detrimentally interferes with the gas discharge so that black spots and specks are produced after a given number of operating hours.
  • the tin oxide coating is very satisfactorily transparent and quite scratch resistant.
  • the tin oxide can also easily be provided during a bulk manufacturing process.
  • the invention is of special importance for those kinds of lamps (furthermore denoted by F-lamps) in which the lamp wall not only has a luminescent coating but also a reflective coating.
  • a reflective coating serves to concentrate the light generated in the luminescent coating in a given direction.
  • the reflective coating is present between the glass wall and the luminescent coating but it is not provided over the entire circumference of the glass envelope.
  • Two differ ent types of lamps can be distinguished in this respect, namely those in which the luminescent coating extends over the entire circumference and those in which the luminescent coating and hence the reflective coating leave a apertured part of the glass wall uncoated.
  • Lamps of the latter type are thus the same as the S-lamps described above, but have a reflective coating between the luminescent coating and the glass wall.
  • the reflective coating and the luminescent coating may extend or not extend over the same circumferential angle.
  • Granular titanium dioxide is commonly used as a material for the reflective coatmg.
  • the reflective coating may alternatively be firstly provided on the wall, followed by the protective coating and the luminescent coating. It is true that a slightly better adhesion of the reflective coating is then obtained, but when using a protective coating of titanium dioxide three times sintering remains necessary. In addition a large quantity of titanium dioxide is required to form the protective coating because the sintered reflective coating is very porous.
  • a protective coating of tin oxide according to the invention may be formed in situ from a suitable organic tin compound such as, for example, dibutyltinmaleate on a reflective coating which has not been previously sintered. Thus one of thr three sintering operations is then omitted. Moreover, less material is used for the protective coating because this coating in case of a suitable solvent being chosen is directly provided on the reflective coating which still comprises binder and is thus not porous for the organic tin compound.
  • a suitable organic tin compound such as, for example, dibutyltinmaleate
  • lamps are obtained in which the tin oxide is directly supportted by the glass wall at those areas where there is no reflective coating and is located between the reflective coating and the luminescent coating in the other part of the lamp.
  • the tin oxide coating of a suitably chosen organic tin compound such as, for example, dibutyltinmaleate may of course alternatively be provided in situ in lamps in which the protective tin oxide coating is directly supported by the glass wall over the entire circumference of the lamp.
  • the drawing shows in a cross-sectional view an F- lamp in which the protective coating of tin oxide in the aperture is supported by the glass wall and is furthermore located between the reflective coating and the luminescent coating.
  • FIG. 1 is the glass wall
  • 2 is the reflective coating, for example, of titanium dioxide
  • 3 is the tin oxide coating having a resistance per square of more than 10,000 Ohm
  • 4 is the luminescent coating, for example, of willemite.
  • the drawing clearly shows that in the aperture which is denoted by 5 the glass wall I is only coated with the protective tin oxide coating 4. There is no reflective coating and no luminescent coating in the aperture.
  • the glass tube 1 is brought to a vertical position before the stems with the electrodes and the exhaust tube are provided and is coated with the desired reflective coating by injection or raising a titanium dioxide suspension.
  • the suspension used for this purpose is prepared by suspending 800 gms of granular TiO in 400 ml of butylacetate to which 25 ml of dibutylphtalate have been added. After this suspension has been ground for 7 hours in a ball mill, 280 ml of a 1% solution of nitrocellulose in butylacetate is added and grinding takes place for another hour.
  • the TiO -coating After the TiO -coating is provided it is dried with the aid of hot air of l 8-25C for approximately 10 minutes and butylacetate evaporates but nitrocellulose and dibutylphtalate remain. Subsequently a strip-shaped part of the TiO, coating is wiped off over the entire tube length with the aid of a vulcalon plate.
  • the partly coated tube wall thus obtained is then coated, by means of injection or raising in the tube, with a thin coating of a solution having the following composition:
  • the tube having the two coatings is introduced into a furnace and heated for 50 to 150 seconds at a temperature of approximately 580C.
  • Dibutylphtalate, nitrocellulose and ethylcellulose thereby evaporate and burn out and dibutyltinmaleate is converted into a tin oxide layer having a resistance per square of at least 10,000 Ohm.
  • the luminescent coating is provided by injecting or raising a suspension of willemite in the vertically placed tube.
  • the suspension used for this purpose is manufactured by grinding gms of willemite for 2 hours in a ball mill in 400 mls of a 1% solution of nitrocellulose in a mixture of 95% butylacetate and 5% rnonoethylglycolaether to which V2% by volume of dibutylphthalate, 2 gms of Sb O and 6 gms of Sr,P O, have been added.
  • the tube having three coatings obtained after this operation is finished in known manner to a fluorescent lamp particularly intended for photo-copying purposes by providing steps with electrodes, exhausting, filling, operating etc.
  • a low-pressure mercury vapour discharge lamp which comprises a glass envelope whose inner side has a luminescent coating and a transparent metal oxide coating, said metal oxide coating consists of tin oxide and has a resistance per square of at least 10,000 Ohm.
  • a low-pressure mercury vapour discharge lamp as claimed in claim 1 in which a light reflective coating is provided between the glass wall and part of the luminescent coating, wherein the tin oxide coating is directly provided on the glass wall at the area where there' is no light reflective coating and is located between the light reflective coating and the luminescent coating in the other part of the lamp.

Landscapes

  • Formation Of Various Coating Films On Cathode Ray Tubes And Lamps (AREA)
  • Vessels And Coating Films For Discharge Lamps (AREA)
US412606A 1972-11-25 1973-11-05 Low-pressure mercury vapour discharge lamp and method of manufacturing said lamp Expired - Lifetime US3875454A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/516,633 US3984589A (en) 1972-11-25 1974-10-21 Method of manufacturing a low pressure mercury vapor discharge lamp

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NLAANVRAGE7216025,A NL171756C (nl) 1972-11-25 1972-11-25 Lagedrukkwikdampontladingslamp en werkwijze voor de vervaardiging daarvan.

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US05/516,633 Division US3984589A (en) 1972-11-25 1974-10-21 Method of manufacturing a low pressure mercury vapor discharge lamp

Publications (1)

Publication Number Publication Date
US3875454A true US3875454A (en) 1975-04-01

Family

ID=19817430

Family Applications (1)

Application Number Title Priority Date Filing Date
US412606A Expired - Lifetime US3875454A (en) 1972-11-25 1973-11-05 Low-pressure mercury vapour discharge lamp and method of manufacturing said lamp

Country Status (8)

Country Link
US (1) US3875454A (OSRAM)
JP (1) JPS5139955B2 (OSRAM)
BE (1) BE807769A (OSRAM)
CA (1) CA984891A (OSRAM)
DE (1) DE2355268C2 (OSRAM)
FR (1) FR2208189B3 (OSRAM)
GB (1) GB1450785A (OSRAM)
NL (1) NL171756C (OSRAM)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2644821A1 (de) * 1975-10-06 1977-04-14 Gte Sylvania Inc Leuchtstofflampe mit reflektorschicht
US4058639A (en) * 1975-12-09 1977-11-15 Gte Sylvania Incorporated Method of making fluorescent lamp
US4500810A (en) * 1980-11-25 1985-02-19 North American Philips Lighting Corporation Fluorescent lamp having integral light-filtering means and starting aid
EP0402878A1 (en) * 1989-06-13 1990-12-19 Mitsubishi Denki Kabushiki Kaisha Low pressure rare gas discharge lamp
US5557170A (en) * 1993-12-24 1996-09-17 U.S. Philips Corporation Low-pressure discharge lamp and method of manufacturing a low-pressure discharge lamp
US20030234611A1 (en) * 2002-06-19 2003-12-25 Klinedinst Keith A. Control of leachable mercury in fluorescent lamps

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3205394A (en) * 1960-04-06 1965-09-07 Sylvania Electric Prod Fluorescent lamp having a sio2 coating on the inner surface of the envelope
US3225241A (en) * 1959-07-09 1965-12-21 Sylvania Electric Prod Aperture fluorescent lamp
US3350598A (en) * 1965-12-29 1967-10-31 Sylvania Electric Prod High pressure electric discharge device containing a fill of mercury, halogen and an alkali metal and barrier refractory oxide layers
US3624444A (en) * 1969-07-05 1971-11-30 Philips Corp Low-pressure mercury vapor discharge lamp
US3676729A (en) * 1969-06-23 1972-07-11 Sylvania Electric Prod Arc discharge lamp having a thin continuous film of indium oxide on the inner surface thereof

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE559838A (OSRAM) * 1957-01-12
US3141990A (en) * 1960-04-06 1964-07-21 Sylvania Electric Prod Fluorescent lamp having a tio2 coating on the inner surface of the bulb

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3225241A (en) * 1959-07-09 1965-12-21 Sylvania Electric Prod Aperture fluorescent lamp
US3205394A (en) * 1960-04-06 1965-09-07 Sylvania Electric Prod Fluorescent lamp having a sio2 coating on the inner surface of the envelope
US3350598A (en) * 1965-12-29 1967-10-31 Sylvania Electric Prod High pressure electric discharge device containing a fill of mercury, halogen and an alkali metal and barrier refractory oxide layers
US3676729A (en) * 1969-06-23 1972-07-11 Sylvania Electric Prod Arc discharge lamp having a thin continuous film of indium oxide on the inner surface thereof
US3624444A (en) * 1969-07-05 1971-11-30 Philips Corp Low-pressure mercury vapor discharge lamp

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2644821A1 (de) * 1975-10-06 1977-04-14 Gte Sylvania Inc Leuchtstofflampe mit reflektorschicht
US4058639A (en) * 1975-12-09 1977-11-15 Gte Sylvania Incorporated Method of making fluorescent lamp
US4500810A (en) * 1980-11-25 1985-02-19 North American Philips Lighting Corporation Fluorescent lamp having integral light-filtering means and starting aid
EP0402878A1 (en) * 1989-06-13 1990-12-19 Mitsubishi Denki Kabushiki Kaisha Low pressure rare gas discharge lamp
US5187415A (en) * 1989-06-13 1993-02-16 Mitsubishi Denki Kabushiki Kaisha Low-pressure rare gas discharge lamp and method for lighting same
US5557170A (en) * 1993-12-24 1996-09-17 U.S. Philips Corporation Low-pressure discharge lamp and method of manufacturing a low-pressure discharge lamp
US20030234611A1 (en) * 2002-06-19 2003-12-25 Klinedinst Keith A. Control of leachable mercury in fluorescent lamps
US6741030B2 (en) * 2002-06-19 2004-05-25 Osram Sylvania Inc. Control of leachable mercury in fluorescent lamps

Also Published As

Publication number Publication date
GB1450785A (en) 1976-09-29
FR2208189A1 (OSRAM) 1974-06-21
BE807769A (fr) 1974-05-24
NL7216025A (OSRAM) 1974-05-28
FR2208189B3 (OSRAM) 1976-10-08
JPS4983277A (OSRAM) 1974-08-10
NL171756B (nl) 1982-12-01
DE2355268A1 (de) 1974-06-06
NL171756C (nl) 1983-05-02
CA984891A (en) 1976-03-02
DE2355268C2 (de) 1983-07-28
JPS5139955B2 (OSRAM) 1976-10-30

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