EP1875488A2 - Low-pressure gas discharge lamp comprising halides of indium and sodium - Google Patents
Low-pressure gas discharge lamp comprising halides of indium and sodiumInfo
- Publication number
- EP1875488A2 EP1875488A2 EP06727927A EP06727927A EP1875488A2 EP 1875488 A2 EP1875488 A2 EP 1875488A2 EP 06727927 A EP06727927 A EP 06727927A EP 06727927 A EP06727927 A EP 06727927A EP 1875488 A2 EP1875488 A2 EP 1875488A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- gas discharge
- low
- pressure gas
- discharge lamp
- indium
- 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.)
- Withdrawn
Links
Classifications
-
- 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
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/12—Selection of substances for gas fillings; Specified operating pressure or temperature
- H01J61/125—Selection of substances for gas fillings; Specified operating pressure or temperature having an halogenide as principal component
Definitions
- DE 100 44 562 Al discloses a low-pressure gas discharge lamp comprising a gas discharge vessel with a filling containing an indium compound and a buffer gas in combination with phosphors.
- a gas discharge vessel with a filling containing an indium compound and a buffer gas in combination with phosphors.
- high luminous efficacy it is most beneficial, when the visible light is generated from the discharge and not via conversion of discharge radiation into visible light because the intrinsic Stokes shift in case of the conversion reduces the luminous efficacy of the generated visible light.
Abstract
The invention relates to a low-pressure gas discharge lamp comprising a gas discharge vessel with means for generating and maintaining a low-pressure gas discharge. It is an object of the invention to improve the luminous efficacy of a low- pressure gas discharge lamp containing a gas filling with an indium compound. According to the invention this is achieved by a low-pressure gas discharge lamp where less luminescence processes are employed. The low-pressure gas discharge lamp comprises a gas discharge vessel containing a gas filling on the basis of an indium halide InX, where X = F, Cl, Br, I, or a mixture of several indium halides. As a characteristic feature the gas filling includes additionally a sodium halide NaX, where X = F, Cl, Br, I, or a mixture of several sodium halides. The additional component consisting of one or more sodium halides emits light in the range of 590 nanometers. Use of a red phosphor in order to gain white light is superfluous then. The gas discharge emits light with a wavelength of 451 nanometers, blue and green light of one or more phosphors converting the UV radiation and light with a wavelength of 590 nanometers.
Description
LOW-PRESSURE GAS DISCHARGE LAMP COMPRISING HALIDES OF INDIUM AND SODIUM
The invention relates to a low-pressure gas discharge lamp comprising a gas discharge vessel with means for generating and maintaining a low-pressure gas discharge.
Light generation in low-pressure gas discharge lamps is based on the principle that charge carriers, particularly electrons but also ions, are accelerated so strongly by an electric field coupled into the lamp with or without electrodes, i.e. capacitively or inductively, that collisions with the gas atoms or molecules in the gas filling of the lamp cause the gas atoms or molecules to be excited or ionized. When returning to lower states or the ground state, a more or less substantial part of the excitation energy is converted to radiation. Conventional low-pressure gas discharge lamps comprise mercury in the gas filling but it is known already that mercury in the gas filling of low-pressure gas discharge lamps can be substituted with other less harmful and toxic substances.
Indium compounds for example are a preferred gas filling. The emission of the discharge consists of the characteristic emission lines of indium at 410 and 451 nanometers, at 304 and 326 nanometers and a continuum between 320 and 450 nanometers. The specific choice of the indium compound used determines the exact position of the continuum.
A general drawback of conventional low-pressure gas discharge lamps for lighting purposes resides in the fact that the substances in the gas filling primarily emit radiation in the short-wave, high-energy, yet invisible range of the electromagnetic spectrum, which radiation must first be converted by phosphors to visible radiation with a much lower energy level. With indium the characteristic emission line at 451 nanometers provides blue light but all other emission lines fall within the invisible range.
Low-pressure gas discharge lamps therefore comprise a phosphor layer containing at least one phosphor emitting in the intended range of the spectrum.
Depending on the application radiation with different wavelengths in a certain range is provided by an adequate phosphor layer.
DE 100 44 562 Al discloses a low-pressure gas discharge lamp comprising a gas discharge vessel with a filling containing an indium compound and a buffer gas in combination with phosphors. With respect to high luminous efficacy it is most beneficial, when the visible light is generated from the discharge and not via conversion of discharge radiation into visible light because the intrinsic Stokes shift in case of the conversion reduces the luminous efficacy of the generated visible light.
The luminous efficacy, expressed in lumen/Watt is the ratio between the total luminous flux emitted by the lamp and the total optical power emitted by the lamp. The luminous efficiency, also expressed in lumen/Watt is the ratio between the total luminous flux emitted by the lamp and the total power input to the lamp. Luminous efficiency is equal to luminous efficacy multiplied by the efficiency with which electrical power is converted into optical power.
It is an object of the invention to improve the luminous efficacy and the luminous efficiency, respectively of a low-pressure gas discharge lamp containing a gas filling with an indium compound.
According to the invention this is achieved by a low-pressure gas discharge lamp where less luminescence processes are employed. The low-pressure gas discharge lamp comprises a gas discharge vessel containing a gas filling on the basis of an indium halide InX, where X = F, Cl, Br, I, or a mixture of several indium halides. As a characteristic feature the gas filling includes additionally a sodium halide NaX, where X = F, Cl, Br, I, or a mixture of several sodium halides. The additional component consisting of one or more sodium halides emits light in the range of 590 nanometers. Use of a red phosphor in order to gain white light is superfluous then. The gas discharge lamp according to the invention emits light with a wavelength of 451 nanometers, blue and green light of one or more phosphors converting the UV radiation and light with a wavelength of 590 nanometers.
A further critical point is the partial vapor pressure pNax of the sodium halide being very small compared to the partial vapor pressure pinx of the indium halide. Therefore it is impossible to vaporize both components to a similar degree. As an effect radiation of sodium halide in the characteristic range of 590 nanometers is very weak compared to radiation of indium halide in the characteristic range of 451 nanometers.
In a preferred embodiment the gas filling therefore comprises a salt mixture of indium monohalides and sodium halides with the indium monohalide content being very small. According to Raoult' s Law the salt components are vaporized according to their concentration and therefore the relation between the vaporized components can be controlled by providing a certain mixing ratio. The molar ratio n( InX) : n( NaX) is preferably < 1 %o, especially < 10"4 in order to gain corresponding partial vapor pressures: pinx (T) = pNax (T), dependent from the vessel temperature T.
In a further preferred embodiment the halogen employed is bromine.
In a further preferred embodiment the components a mixed in a ratio to gain white light.
In accordance with the invention a molecular gas discharge takes place at low pressure, which gas discharge emits radiation in the visible range of the electromagnetic spectrum. This way direct use is made from the radiation of the discharge and Stokes shift losses caused by a luminescence process are avoided or at least reduced.
In combination with a phosphor layer, the lamp in accordance with the invention has a luminescence process which is substantially more efficient than that of conventional low-pressure discharge lamps. As a consequence the lamp in accordance with the invention has in general a higher luminous efficacy.
Claims
1. A low-pressure gas discharge lamp comprising a gas discharge vessel containing a gas filling on the basis of an indium halide InX, where X = F, Cl, Br, I , or a mixture of several indium halides, characterized in that the gas filling includes additionally a sodium halide NaX, where X = F, Cl, Br, I, or a mixture of several sodium halides.
2. A low-pressure gas discharge lamp as claimed in claim 1, characterized in that in the gas discharge vessel contains indium monohalide InX with a molar ratio n( InX) : n( NaX) < 1 %o.
3. A low-pressure gas discharge lamp as claimed in claim 2, characterized in that in the gas discharge vessel contains indium monohalide InX with a molar ratio n( InX) : n( NaX) < 10"4.
4. A low-pressure gas discharge lamp as claimed in one of the preceding claims, characterized in that X = Br.
5. A low-pressure gas discharge lamp as claimed in one of the preceding claims, characterized in that the components of the gas filling and the phosphors are chosen in order to gain emission from the phosphor layer together with the emission from the gas discharge forming white light in the visible range.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP06727927A EP1875488A2 (en) | 2005-04-20 | 2006-04-13 | Low-pressure gas discharge lamp comprising halides of indium and sodium |
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05103201 | 2005-04-20 | ||
EP06727927A EP1875488A2 (en) | 2005-04-20 | 2006-04-13 | Low-pressure gas discharge lamp comprising halides of indium and sodium |
PCT/IB2006/051159 WO2006111902A2 (en) | 2005-04-20 | 2006-04-13 | Low-pressure gas discharge lamp comprising halides of indium and sodium |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1875488A2 true EP1875488A2 (en) | 2008-01-09 |
Family
ID=37115529
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP06727927A Withdrawn EP1875488A2 (en) | 2005-04-20 | 2006-04-13 | Low-pressure gas discharge lamp comprising halides of indium and sodium |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP1875488A2 (en) |
JP (1) | JP2008537303A (en) |
CN (1) | CN101164135A (en) |
WO (1) | WO2006111902A2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9064024B2 (en) | 2007-08-21 | 2015-06-23 | Google Inc. | Bundle generation |
US7990040B2 (en) * | 2008-06-11 | 2011-08-02 | General Electric Company | Phosphor for high CRI lamps |
Family Cites Families (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR90083E (en) * | 1966-05-27 | 1967-10-06 | Lampes Sa | Device applicable to electric discharge lamps containing metal iodides in saturating vapor, in particular sodium iodide |
NL164423C (en) * | 1969-12-13 | 1980-12-15 | Philips Nv | LOW PRESSURE SODIUM VAPOR DISCHARGE LAMP. |
GB8915611D0 (en) * | 1989-07-07 | 1989-08-23 | Emi Plc Thorn | A discharge tube arrangement |
JPH03152852A (en) * | 1989-11-08 | 1991-06-28 | Matsushita Electric Works Ltd | Discharge lamp of high brightness and electrodeless discharge lamp device |
DE10044562A1 (en) * | 2000-09-08 | 2002-03-21 | Philips Corp Intellectual Pty | Low pressure gas discharge lamp with mercury-free gas filling |
DE10242241A1 (en) * | 2002-09-12 | 2004-03-25 | Philips Intellectual Property & Standards Gmbh | Low pressure discharge lamp comprises a gas discharge vessel containing a noble gas filling, electrodes and devices for producing and maintaining a low pressure gas discharge, and an electron emitter substance |
-
2006
- 2006-04-13 WO PCT/IB2006/051159 patent/WO2006111902A2/en not_active Application Discontinuation
- 2006-04-13 JP JP2008507231A patent/JP2008537303A/en not_active Withdrawn
- 2006-04-13 EP EP06727927A patent/EP1875488A2/en not_active Withdrawn
- 2006-04-13 CN CNA2006800130390A patent/CN101164135A/en active Pending
Non-Patent Citations (1)
Title |
---|
See references of WO2006111902A3 * |
Also Published As
Publication number | Publication date |
---|---|
WO2006111902A2 (en) | 2006-10-26 |
WO2006111902A3 (en) | 2007-03-08 |
CN101164135A (en) | 2008-04-16 |
JP2008537303A (en) | 2008-09-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN100347266C (en) | Yellow light-emitting halophosphate phosphors and light sources incorporating same | |
US6972521B2 (en) | Low-pressure gas discharge lamp having a mercury-free gas filling with an indium compound | |
JP2002124211A5 (en) | ||
JP4460799B2 (en) | Plasma display panel using excimer gas | |
US6844671B2 (en) | High luminosity phosphor blends for generating white light from near-UV/blue light-emitting devices | |
US20110031880A1 (en) | Street lighting lamp with long life, high efficiency, and high lumen maintenance | |
CN1156896A (en) | Metal halide lamp | |
KR20080003702A (en) | Uv-emitting phosphor and lamp containing same | |
WO2006111902A2 (en) | Low-pressure gas discharge lamp comprising halides of indium and sodium | |
US7391154B2 (en) | Low-pressure gas discharge lamp with gas filling containing tin | |
US3832591A (en) | High luminous efficacy white appearing lamp | |
US20080258623A1 (en) | Low Pressure Discharge Lamp Comprising a Metal Halide | |
EP1494263A2 (en) | Light sources for improving visual perceptions under mesopic lighting conditions | |
EP1618594A1 (en) | High-pressure metal halide discharge lamp | |
US20070222389A1 (en) | Low Pressure Discharge Lamp Comprising a Discharge Maintaining Compound | |
GB2054261A (en) | Metal halide high-intensity discharge lamps | |
US20090184644A1 (en) | High-pressure mercury vapor lamp | |
WO2008120172A2 (en) | Gas discharge lamp comprising a mercury-free gas fill | |
US20080203890A1 (en) | Low-Pressure Gas Discharge Lamp Having a Gallium-Containing Gas Filling | |
JPH0448547A (en) | Light emitting device | |
US20090072703A1 (en) | Low-pressure discharge lamp | |
JP2005538523A (en) | Low pressure gas discharge lamp with a mixture of alkaline earth oxides as electron emissive material | |
US7944148B2 (en) | Mercury free tin halide compositions and radiation sources incorporating same | |
SU1327204A1 (en) | Luminescent lamp for electrooptic devices of plant protection |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20071120 |
|
AK | Designated contracting states |
Kind code of ref document: A2 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC NL PL PT RO SE SI SK TR |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN |
|
18W | Application withdrawn |
Effective date: 20080507 |