EP0444591A2 - Metal vapour discharge lamp - Google Patents
Metal vapour discharge lamp Download PDFInfo
- Publication number
- EP0444591A2 EP0444591A2 EP91102795A EP91102795A EP0444591A2 EP 0444591 A2 EP0444591 A2 EP 0444591A2 EP 91102795 A EP91102795 A EP 91102795A EP 91102795 A EP91102795 A EP 91102795A EP 0444591 A2 EP0444591 A2 EP 0444591A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- iron
- discharge lamp
- vapor discharge
- thallium
- metal vapor
- 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- Withdrawn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
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 31
- 239000002184 metal Substances 0.000 title claims abstract description 31
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 77
- 229910052742 iron Inorganic materials 0.000 claims abstract description 38
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052716 thallium Inorganic materials 0.000 claims abstract description 18
- 229910052753 mercury Inorganic materials 0.000 claims abstract description 15
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 claims abstract description 15
- -1 thallium halide Chemical class 0.000 claims description 4
- 230000008021 deposition Effects 0.000 claims description 3
- 238000010891 electric arc Methods 0.000 claims 1
- 229910052736 halogen Inorganic materials 0.000 claims 1
- 150000002367 halogens Chemical class 0.000 claims 1
- 238000001228 spectrum Methods 0.000 abstract description 12
- 238000000151 deposition Methods 0.000 abstract description 4
- 230000015572 biosynthetic process Effects 0.000 abstract description 2
- 239000003973 paint Substances 0.000 description 7
- 239000010408 film Substances 0.000 description 5
- 239000000976 ink Substances 0.000 description 5
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 4
- 238000000016 photochemical curing Methods 0.000 description 4
- 238000006552 photochemical reaction Methods 0.000 description 4
- 238000001723 curing Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000014759 maintenance of location Effects 0.000 description 3
- 230000001939 inductive effect Effects 0.000 description 2
- 229910001507 metal halide Inorganic materials 0.000 description 2
- 150000005309 metal halides Chemical class 0.000 description 2
- 239000010409 thin film Substances 0.000 description 2
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000011888 foil Substances 0.000 description 1
- 150000004820 halides Chemical class 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- NDKKKEPYKOOXLG-UHFFFAOYSA-L mercury(1+);diiodide Chemical compound [Hg]I.[Hg]I NDKKKEPYKOOXLG-UHFFFAOYSA-L 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- CMJCEVKJYRZMIA-UHFFFAOYSA-M thallium(i) iodide Chemical compound [Tl]I CMJCEVKJYRZMIA-UHFFFAOYSA-M 0.000 description 1
- 229910052724 xenon Inorganic materials 0.000 description 1
- FHNFHKCVQCLJFQ-UHFFFAOYSA-N xenon atom Chemical compound [Xe] FHNFHKCVQCLJFQ-UHFFFAOYSA-N 0.000 description 1
Images
Classifications
-
- 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
- H01J61/18—Selection of substances for gas fillings; Specified operating pressure or temperature having a metallic vapour as the principal constituent
Definitions
- This invention relates to a metal vapor discharge lamp to be employed for photochemical reactions or curing of paints and inks.
- Ultraviolet rays are often used for inducing photochemical reactions or curing paints and inks, and those having a wavelength in the range of about 280 to 400 nm are useful for such purposes.
- High-pressure mercury vapor discharge lamps have conventionally been used as sources of such ultraviolet rays.
- the light emitted from a high-pressure mercury vapor discharge lamp consists of a multiplicity of luminescent line spectra, and each spectrum distributes over a considerably broad range of wavelength. Accordingly, it is not efficient to use the high-pressure mercury vapor discharge lamp to achieve photochemical reactions or curing of paints, in which the effective wavelength range is about 280 to 400 nm as described above.
- the ultraviolet rays must penetrate through the layer of the material to be cured such as a paint or an ink so that it can completely be cured, it requires a considerable time to achieve the complete curing only with the aid of the luminescent line spectrum of mercury.
- a metal vapor discharge lamp is frequently used, which has an increased quantity of light emission in the effective wavelength range by using a metal halide-filled bulb.
- an iron-filled metal vapor discharge lamp is particularly convenient to achieve curing of paints and inks since it continuously emits ultraviolet rays in the wavelength range of 350 to 400 nm.
- halide of thallium is effective for achieving the above objects, and they made various experiments to accomplish this invention.
- a metal thallium or a thallium halide into the metal vapor discharge lamp having mercury and iron filled therein in such a way that the gram atom number ratio of Tl/Fe may be 1/200 to 1/2, deposition of iron on the internal wall surface of the bulb to form a thin film can be prevented, and thus output of the ultraviolet rays can be maintained for a long time.
- Fig. 1 shows a cross section of a metal vapor discharge lamp
- Fig. 2 shows characteristic curves demonstrating high % output retention achieved according to this invention.
- Fig. 1 shows a metal vapor discharge lamp with a rated power of 4 KW to be used as a light source for curing paints or inks.
- This metal vapor discharge lamp has a tubular quartz bulb 1 with an internal diameter of 22 mm, and a pair of electrodes 2,2 disposed therein to oppose each other with a distance of 250 mm therebetween.
- the bulb 1 has a sealed portion 11 at each end, and a molybdenum foil 3 is sealed therein, which connects the corresponding electrode 2 with an outer lead 4.
- the bulb 1 In the bulb 1 are filled 120 mg of a metal mercury (Hg), 13 mg of mercury iodide (Hg2I2), 3.5 mg of iron (Fe), 1.1 mg of thallium iodide (TlI) and 30 mmHg of xenon gas.
- Hg metal mercury
- Hg2I2 mercury iodide
- Fe iron
- TlI thallium iodide
- the amount of thallium to be incorporated relative to iron is 1/19 in terms of gram atom number ratio.
Landscapes
- Discharge Lamp (AREA)
Abstract
Disclosed is a metal vapor discharge lamp having mercury and iron filled therein, in which the iron is prevented from depositing on the internal surface of the bulb of said lamp and forming a thin iron film. Namely, in the metal vapor discharge lamp according to this invention, the amount of thallium to be incorporated relative to iron is 1/200 to 1/2 in terms of gram atom number ratio, whereby formation of thin iron film can be prevented without affecting the spectrum outputs of mercury and iron.
Description
- This invention relates to a metal vapor discharge lamp to be employed for photochemical reactions or curing of paints and inks.
- Ultraviolet rays are often used for inducing photochemical reactions or curing paints and inks, and those having a wavelength in the range of about 280 to 400 nm are useful for such purposes.
- High-pressure mercury vapor discharge lamps have conventionally been used as sources of such ultraviolet rays. However, the light emitted from a high-pressure mercury vapor discharge lamp consists of a multiplicity of luminescent line spectra, and each spectrum distributes over a considerably broad range of wavelength. Accordingly, it is not efficient to use the high-pressure mercury vapor discharge lamp to achieve photochemical reactions or curing of paints, in which the effective wavelength range is about 280 to 400 nm as described above. In other words, while the ultraviolet rays must penetrate through the layer of the material to be cured such as a paint or an ink so that it can completely be cured, it requires a considerable time to achieve the complete curing only with the aid of the luminescent line spectrum of mercury. In order to cope with such problem, a metal vapor discharge lamp is frequently used, which has an increased quantity of light emission in the effective wavelength range by using a metal halide-filled bulb. Further, an iron-filled metal vapor discharge lamp is particularly convenient to achieve curing of paints and inks since it continuously emits ultraviolet rays in the wavelength range of 350 to 400 nm.
- However, if such iron-filled metal vapor discharge lamp is lit for a long time, the iron deposits on the internal wall surface of the bulb to form a thin film, so that the amount of the iron which can contribute to light emission will be reduced, and the thin iron film formed inhibits transmission of the ultraviolet rays therethrough to reduce output of the ultraviolet rays.
- In order to solve the above problem, it was disclosed to additionally incorporate lead to an iron-filled metal vapor discharge lamp (Japanese Patent Publication No. 15503/1979). This type of metal vapor discharge lamp additionally containing lead can attain the intended object of preventing formation of thin iron film and maintaining output of the ultraviolet rays, but the output of the luminescent line spectra of mercury in the wavelengths of 302, 313 and 365 nm in the above range are extremely reduced by the presence of the lead. Accordingly, the metal vapor discharge lamp additionally containing lead is rarely used for the purpose of inducing photochemical reactions or curing paints. On other hand, it is also disclosed to additionally incorporate tin to an iron-filled metal vapor discharge lamp (Japanese Patent Publication No. 18743/1983). In this type of metal vapor discharge lamp either, the tin notably reduces the output of the luminescent line spectra of mercury as in the case of lead.
- It is a first object of this invention to provide a metal vapor discharge lamp having mercury and iron filled therein, in which the iron is prevented from depositing on the internal surface of the bulb so that emission of ultraviolet rays may not be hindered.
- It is a second object of this invention to provide a metal vapor discharge lamp having mercury and iron filled therein, in which the luminescent spectra of mercury and iron are designed not to be affected.
- The present inventors found that halide of thallium (Tℓ) is effective for achieving the above objects, and they made various experiments to accomplish this invention. To describe in detail, by additionally incorporating a metal thallium or a thallium halide into the metal vapor discharge lamp having mercury and iron filled therein in such a way that the gram atom number ratio of Tℓ/Fe may be 1/200 to 1/2, deposition of iron on the internal wall surface of the bulb to form a thin film can be prevented, and thus output of the ultraviolet rays can be maintained for a long time. It should be noted, however, if the amount of thallium incorporated relative to iron is less than 1/200 in terms of the gram atom number ratio, the effect of inhibiting deposition of iron on the internal surface of the bulb will be low, whereby the output of ultraviolet rays may not sufficiently be maintained; whereas if the amount of thallium relative to iron is more than 1/2 in terms of gram atom number ratio, the luminescent spectra of iron will slightly be weakened.
- Fig. 1 shows a cross section of a metal vapor discharge lamp; and Fig. 2 shows characteristic curves demonstrating high % output retention achieved according to this invention.
- Fig. 1 shows a metal vapor discharge lamp with a rated power of 4 KW to be used as a light source for curing paints or inks. This metal vapor discharge lamp has a tubular quartz bulb 1 with an internal diameter of 22 mm, and a pair of
electrodes portion 11 at each end, and amolybdenum foil 3 is sealed therein, which connects thecorresponding electrode 2 with anouter lead 4. In the bulb 1 are filled 120 mg of a metal mercury (Hg), 13 mg of mercury iodide (Hg₂I₂), 3.5 mg of iron (Fe), 1.1 mg of thallium iodide (TℓI) and 30 mmHg of xenon gas. The amount of thallium to be incorporated relative to iron is 1/19 in terms of gram atom number ratio. - When the above metal vapor discharge lamp was lit, it showed an initial lamp current of 12.5 A at the lamp output of 4 KW, and no iron deposited on the internal surface of the bulb 1, when the above metal vapor discharge lamp was lit for 1,000 hours, to form no thin iron film. The variation in the output of ultraviolet rays in the wavelength range of 280 to 400 nm was measured as shown by the characteristic curve A in Fig. 2, indicating an output retention of 90 % after 1,000 hours of lighting test.
- Incidentally, when the above lighting test was repeated using the same metal vapor discharge lamp except that it does not contain thallium as a control, iron started to deposit on the internal surface of the bulb 1 after about several tens of hours to form a thin iron film, and as shown by the characteristic curve B in Fig. 2, % output retention dropped to 50 % after 1,000 hours.
- Next, the effect of the thallium incorporated to the metal vapor discharge lamp in which no thin iron film had yet been formed on the output of the luminescent line spectra of mercury and that of iron was investigated. It was found that the decrease in the spectrum output of mercury was 3 % and that of iron was 5 % which are insignificant values compared with those in the metal vapor discharge lamp containing no thallium. On the other hand, in those metal vapor discharge lamps which contain lead or tin instead of thallium, the decrease in the spectrum output of mercury was 35 % in the case of lead and 28 % in the case of tin. The above results prove that thallium substantially does not affect the spectrum output of mercury. Further, the addition of thallium gives no substantial affect on the electrical characteristics such as starting current and reignition voltage.
- While a metal iron and thallium halide were additionally incorporated in this embodiment, they may be replaced by an iron halide and a metal thallium. The same effect can be obtained by using a mixture of such metals and metal halides.
Claims (1)
- A metal vapor discharge lamp comprising a bulb with electrodes containing suitable amounts of iron and a halogen together with sufficient amounts of mercury and a rare gas for maintaining arc discharge to occur, characterized in that a metal thallium or a thallium halide is additionally incorporated so that the amount of thallium relative to the iron may be 1/200 to 1/2 in terms of gram atom number ratio, whereby to prevent deposition of the iron to form a thin iron film.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP44414/90 | 1990-02-27 | ||
| JP4441490A JPH03250549A (en) | 1990-02-27 | 1990-02-27 | Metal vapor electric discharge lamp |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0444591A2 true EP0444591A2 (en) | 1991-09-04 |
| EP0444591A3 EP0444591A3 (en) | 1991-11-06 |
Family
ID=12690845
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19910102795 Withdrawn EP0444591A3 (en) | 1990-02-27 | 1991-02-26 | Metal vapour discharge lamp |
Country Status (2)
| Country | Link |
|---|---|
| EP (1) | EP0444591A3 (en) |
| JP (1) | JPH03250549A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0536577A1 (en) * | 1991-10-10 | 1993-04-14 | Heraeus Noblelight GmbH | Discharge tube and control of an apparatus provided with same |
| EP0616357A1 (en) * | 1993-03-17 | 1994-09-21 | Ushiodenki Kabushiki Kaisha | Metallic vapour discharge lamp |
| CN102292793A (en) * | 2009-01-26 | 2011-12-21 | 哈利盛东芝照明公司 | Metal halide lamp |
| CN102306609A (en) * | 2010-04-27 | 2012-01-04 | 哈利盛东芝照明公司 | Ultraviolet irradiation apparatus, ultraviolet irradiation method, and method for manufacturing ultraviolet irradiation apparatus |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5069493B2 (en) * | 2006-11-02 | 2012-11-07 | ハリソン東芝ライティング株式会社 | UV discharge lamp |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE570606C (en) * | 1930-03-04 | 1933-02-17 | Siemens Ag | Metal vapor arc lamp |
| JPS5216887A (en) * | 1975-07-30 | 1977-02-08 | Iwasaki Electric Co Ltd | Metal vapor discharge lamp |
| GB2182486B (en) * | 1985-10-04 | 1990-06-06 | Ushio Electric Inc | Magnesium and iron vapor discharge lamp |
-
1990
- 1990-02-27 JP JP4441490A patent/JPH03250549A/en active Pending
-
1991
- 1991-02-26 EP EP19910102795 patent/EP0444591A3/en not_active Withdrawn
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0536577A1 (en) * | 1991-10-10 | 1993-04-14 | Heraeus Noblelight GmbH | Discharge tube and control of an apparatus provided with same |
| EP0616357A1 (en) * | 1993-03-17 | 1994-09-21 | Ushiodenki Kabushiki Kaisha | Metallic vapour discharge lamp |
| US5489819A (en) * | 1993-03-17 | 1996-02-06 | Ushiodenki Kabushiki Kaisha | Method of operating a metallic vapor discharge lamp |
| CN102292793A (en) * | 2009-01-26 | 2011-12-21 | 哈利盛东芝照明公司 | Metal halide lamp |
| CN102306609A (en) * | 2010-04-27 | 2012-01-04 | 哈利盛东芝照明公司 | Ultraviolet irradiation apparatus, ultraviolet irradiation method, and method for manufacturing ultraviolet irradiation apparatus |
| CN102306609B (en) * | 2010-04-27 | 2016-02-17 | 哈利盛东芝照明公司 | The manufacture method of ultraviolet lamp, ultraviolet irradiation method, ultraviolet lamp |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03250549A (en) | 1991-11-08 |
| EP0444591A3 (en) | 1991-11-06 |
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| 18D | Application deemed to be withdrawn |
Effective date: 19920507 |