GB2110869A - Low pressure sodium vapour discharge lamp - Google Patents
Low pressure sodium vapour discharge lamp Download PDFInfo
- Publication number
- GB2110869A GB2110869A GB08232143A GB8232143A GB2110869A GB 2110869 A GB2110869 A GB 2110869A GB 08232143 A GB08232143 A GB 08232143A GB 8232143 A GB8232143 A GB 8232143A GB 2110869 A GB2110869 A GB 2110869A
- Authority
- GB
- United Kingdom
- Prior art keywords
- bulb
- discharge lamp
- sodium
- outer bulb
- vapour discharge
- 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.)
- Granted
Links
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 title claims description 33
- 229910052708 sodium Inorganic materials 0.000 title claims description 33
- 239000011734 sodium Substances 0.000 title claims description 33
- 238000000034 method Methods 0.000 claims abstract description 11
- 238000004519 manufacturing process Methods 0.000 claims abstract description 7
- 239000010445 mica Substances 0.000 claims abstract description 6
- 229910052618 mica group Inorganic materials 0.000 claims abstract description 6
- 229910003437 indium oxide Inorganic materials 0.000 claims abstract description 5
- PJXISJQVUVHSOJ-UHFFFAOYSA-N indium(iii) oxide Chemical compound [O-2].[O-2].[O-2].[In+3].[In+3] PJXISJQVUVHSOJ-UHFFFAOYSA-N 0.000 claims abstract description 5
- 239000011248 coating agent Substances 0.000 claims description 8
- 238000000576 coating method Methods 0.000 claims description 8
- 239000011521 glass Substances 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 7
- 239000002184 metal Substances 0.000 claims description 7
- 239000000443 aerosol Substances 0.000 claims description 5
- 239000000463 material Substances 0.000 claims description 5
- 150000002739 metals Chemical class 0.000 claims description 4
- 230000005855 radiation Effects 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 2
- RHZWSUVWRRXEJF-UHFFFAOYSA-N indium tin Chemical compound [In].[Sn] RHZWSUVWRRXEJF-UHFFFAOYSA-N 0.000 claims 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 abstract description 3
- 238000007664 blowing Methods 0.000 abstract description 3
- 229910052786 argon Inorganic materials 0.000 abstract description 2
- 229910052754 neon Inorganic materials 0.000 abstract description 2
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 5
- 239000007789 gas Substances 0.000 description 3
- 229910052738 indium Inorganic materials 0.000 description 3
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- 229910021627 Tin(IV) chloride Inorganic materials 0.000 description 2
- DKPFZGUDAPQIHT-UHFFFAOYSA-N butyl acetate Chemical compound CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 2
- PSCMQHVBLHHWTO-UHFFFAOYSA-K indium(iii) chloride Chemical compound Cl[In](Cl)Cl PSCMQHVBLHHWTO-UHFFFAOYSA-K 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 150000003606 tin compounds Chemical class 0.000 description 2
- HPGGPRDJHPYFRM-UHFFFAOYSA-J tin(iv) chloride Chemical compound Cl[Sn](Cl)(Cl)Cl HPGGPRDJHPYFRM-UHFFFAOYSA-J 0.000 description 2
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 238000005868 electrolysis reaction Methods 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- GKAOGPIIYCISHV-UHFFFAOYSA-N neon atom Chemical compound [Ne] GKAOGPIIYCISHV-UHFFFAOYSA-N 0.000 description 1
- 229910052756 noble gas Inorganic materials 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000002028 premature Effects 0.000 description 1
- 229910001887 tin oxide Inorganic materials 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J61/00—Gas-discharge or vapour-discharge lamps
- H01J61/02—Details
- H01J61/30—Vessels; Containers
- H01J61/35—Vessels; Containers provided with coatings on the walls thereof; Selection of materials for the coatings
Landscapes
- Vessels And Coating Films For Discharge Lamps (AREA)
Abstract
The outer bulb 2 is formed having domed portion 2A, e.g. by blowing, and its inner surface including the domed portion 2A is coated with an I-R reflective layer transparent to Na "D" lines e.g. indium oxide doped with 12 atom % tin having a thickness of 0.3 microns and a resistance per square of 7-11 ohms. The U-shaped discharge tube 1 supported by a transparent disk 4 e.g. mica, so that light may be emitted through all portions of the outer bulb Disk 4 may rest on bulbous projection 3 on the discharge tube 1 and shoulder 6 on the outer bulb 2. The lamp contains Ne and Ar. Specific examples of the lamp and a method of manufacture are given. <IMAGE>
Description
SPECIFICATION
Sodium vapour discharge lamp
The present invention relates to electric discharge lamps, and in particular to low pressure sodium vapour discharge lamps rated at below about 35 W.
Sodium lamps of this type consist essentially of a sealed elongate discharge tube containing metallic sodium and a noble gas or mixture of such gases under low pressure held within a cylindrical outer bulb coated on its inner surface with a coating transparent to sodium emission but opaque to infra-red emission. Typically the coating consists of indium oxide doped with tin oxide. Hitherto the coated outer bulb used in lamps of this type has been initially formed from an open glass tube, the inner surface of which is sprayed with a mixture of suitable oxidisation indium and tin compounds. One end of the tube is closed, usually to a domed shape, and a mount, through which the leads to the lamp electrodes extend, in sealed to the opposite end after locating the discharge tube within the bulb.In this process it has been found necessary to remove the indium and tin compounds from the regions of the inner surface near the ends of the glass tube to enable the ends of the tube to be sealed. This in turn has made it necessary to mount a metal reflector inside the tube at the domed end, in orderto prevent the loss of infra-red radiation from the uncoated portion of the tube adjacent the seal. The metal reflector has generally formed part of a support assembly for the discharge tube. It has been found difficult to manufacture this combined reflector and support assembly and to mount it satisfactorily within the outer tube, in particular because mica supports have been found necessary in order to insulate the reflector from the inner tube and thereby prevent electrolysis of the glass and premature lamp failure. Furthermore the reflector blocks out some of the sodium emission.
Therefore, an object of the present invention is to simplify the manufacture of sodium vapour discharge lamps. A further object of the invention is to provide a sodium vapour discharge lamp of improved luminous efficacy.
According to one aspect of the present invention, in a sodium vapour discharge lamp incorporating a generally cylindrical outer bulb, having a mount through which the electrode leads extend sealed into one end, the distal end of the bulb is smoothly curved throughout, and substantially the whole of the internal surface of the said distal end is coated with a material which is substantially transparent to sodium 'D' line emission and substantially opaque to infra-red radiation.
Preferably the outer bulb is formed as a blown bulb, the need for a separate step of doming the end prior to coating being thereby avoided.
Preferably the distal end of the outer bulb is of reduced diameter, thereby forming a shoulder which serves to axially locate a resilient support carried by the discharge tube, which support is substantially transparent to sodium emission and serves to locate and align the discharge tube with respect to the outer bulb. Preferably the support is a discrete member and is engaged by one or more shoulders or other projections of the discharge tube which oppose the shoulder in the outer bulb and urge the support into contact therewith. The support is preferably generally in the form of a thin annulus of resilient flexible material which is transparent to sodium emission. The preferred material is mica.A mica support of this type constitutes a particularly simple and reliable means of locating the discharge tube, and enables light to be emitted through virtually every part of the outer bulb.
According to a further aspect of the invention, in a process for manufacturing a coated outer bulb of generally tubular shape suitable for a low pressure sodium vapour discharge lamp, the bulb is formed with a closed end and one or more metals are subsequently deposited onto substantially the whole of the inside surface of a substantial part of the bulb including said end to form a coating substantially opaque to infra-red emission and substantially transparent to sodium 'D' line emission. Preferably the glass bulb is initiallyformed by blowing to the required shape having a closed smoothly curved end. Preferably the said one or more metals are initially deposited as reducable compounds from an aerosol; for example tin may be deposited onto the heated glass as stannic oxide from an aerosol of stannic chloride in air, as is well known.The oxide may subsequently be partially reduced to the metal with hydrogen.
The invention will now be described with reference to the accompanying drawings, of which
Figure 1 is a front elevation of a low pressure sodium lamp in accordance with the invention,
Figure 2 is a section taken on ll-ll of Figure 1,
Figure 3 is a side elevation of the lamp shown in
Figure 1,
Figure 4 is an elevation, partly in section, of apparatus for coating the outer bulb of a low pressure sodium lamp by a method in accordance with the invention, and
Figure 5 is a section on V-V of Figure 4.
Figure 1 shows a low pressure sodium discharge lamp comprising a generally U-shaped discharge tube 1 within a generally cylindrical coated outer bulb 2 formed by blowing with a closed, domed end 2A. The discharge tube 1 incorporates two bulbous projections 3, which extend perpendicular to the plane of the discharge tube 1, as best seen in Figure 3. Athin transparent mica disc 4 pierced with an oval hole 5, as shown more clearly in Figure 2, is supported by the projections 3 and slidingly fits over the discharge tube 1. The disc4 engages a shoulder 6 in the outer envelope 2 which opposes the projections 3 and axially locates the disc which in turn serves to align the discharge tube 1 within the outer bulb 2. The inside diameter of the discharge tube 1 is between 10 and 14 mm, and the length of the discharge path between the terminals is approximately 150 mm.The discharge tube contains a rare gas filling of 98.4% neon and 1.6% argon at a pressure of 1100 Pa. The outer bulb 2 is coated with a layer indium oxide doped with approximately 12 atom % metallic tin with respect to indium. The thickness of this layer is approximately 0.3 lim, giving a resistance per square of approximately 8 ohms. The diameter of the outer bulb is approximately 40 mm.
A sodium discharge lamp as described above with reference to Figures 1 to 3 operates at a power of approximately 10 W at an arc voltage of approximately 55 V, and under these conditions has a luminous efficacy approaching 100 lumens per watt.
Figures 4 and 5 illustrate a process according to the invention for manufacturing a coated outer bulb for a sodium discharge lamp. A cylindrical bulb 2a, open at one end, is rotated about its axis by means (not shown) within a gas or electric furnace 7 at a temperature of approximately 500 C. A delivery tube 7 extends into the cylindrical bulb 2a and is divided into a major section 8 and a minor section 9 by a longitudinal partition, as best seen in Figure 5. A coating solution, consisting of indium trichloride and stannic chloride in appropriate proportions dissolved in n-butyl acetate is injected from the coating solution intake and atomised in a stream of high pressure air from the high pressure air supply.The resulting aerosol is sucked into the rotating tube 2a through section 9 of the delivery tube 7 by an extractor fan located at the outlet of section 8. A partial vacuum is maintained in the bulb 2a by locating its mouth adjacent a wall of the furnace, the remaining air leak 10 ensuring that no aerosol escapes and hence that only the closed end of the bulb 2a is coated, as shown in Figure 4. Under these conditions stannic oxide and indium oxide are uniformly deposited on the area of the rotating tube 2a indicated in Figure 4. When the layer has reached the desired thickness, the deposited oxide film may be reduced by any suitable conventional process. It is necessary to leave a short length of the bulb clear to enable it to be sealed onto the base of the lamp after introduction of the discharge tube into the bulb.
Although the tube 2a is shown as a blow bulb, it will be apparent that the process described above is applicable also to any pre-sealed glass tube.
Claims (11)
1. A sodium vapour discharge lamp incorporating a generally cylindical outer bulb, having a mount through which the electrode leads extend sealed into one end, wherein the distal end of the bulb is smoothly curved throughout and substantially the whole of the internal surface of the said distal end is coated with a material which is substantially transparent to sodium 'D' line emission and substantially opaque to infra-red radiation.
2. A sodium vapour discharge lamp according to
Claim 1 wherein said outer bulb is in the form of a blown bulb.
3. A sodium vapour discharge lamp according to
Claim 1 or Claim 2 incorporating a resilient support carried by a discharge tube wherein said support is axially located by a shoulder in said outer bulb, is substantially transparent to sodium emission and serves to locate and align the discharge tube with respect to the outer bulb.
4. A sodium vapour discharge lamp according to
Claim 3 wherein said support is a discrete member, and is engaged by one or more projections of the discharge tube which oppose the shoulder in the outer bulb and urge said support into contact therewith.
5. A sodium vapour discharge lamp according to
Claim 3 or Claim 4 wherein said support is in the form of a thin annulus of resilient flexible material and is transparent to sodium emission.
6. A sodium vapour discharge lamp according to
Claim 4 or Claim 5 wherein said support is composed of mica.
7. A sodium vapour discharge lamp rated at approximately 10W at an arc voltage of approximately 55V substantially as described hereinabove with reference to Figures 1 to 3 of the accompanying drawings wherein the resistance per square of the indium oxide/tin layer is between 7 and 11 ohms, the length of the discharge path is approximately 150 mm, and the inside diameter of the discharge tube is between 10 and 14 mm.
8. A process for manufacturing a coated outer bulb of generally tubular shape suitable for a low pressure sodium vapour discharge lamp, wherein said bulb is initially formed with a closed end and one or more metals are subsequently deposited onto substantially the whole of the inside surface of a substantial part of said bulb, including said end, to form a coating substantially opaque to infra-red radiation and substantially transparent to sodium emission.
9. A process according to Claim 8 wherein said glass bulb is formed by lowing it to the required shape.
10. A process according to Claim 8 or Claim 9 wherein said one or more metals are initially deposited as reducable compounds from an aerosol and are subsequently reduced.
11. A process for manufacturing a coated outer bulb suitable for a low pressure sodium vapour discharge lamp substantially as described hereinabove with reference to Figure 4 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB08232143A GB2110869B (en) | 1981-11-11 | 1982-11-10 | Low pressure sodium vapour discharge lamp |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8134038 | 1981-11-11 | ||
| GB08232143A GB2110869B (en) | 1981-11-11 | 1982-11-10 | Low pressure sodium vapour discharge lamp |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2110869A true GB2110869A (en) | 1983-06-22 |
| GB2110869B GB2110869B (en) | 1986-08-28 |
Family
ID=26281236
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB08232143A Expired GB2110869B (en) | 1981-11-11 | 1982-11-10 | Low pressure sodium vapour discharge lamp |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2110869B (en) |
-
1982
- 1982-11-10 GB GB08232143A patent/GB2110869B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2110869B (en) | 1986-08-28 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4717607A (en) | Method of making a fluorescent lamp | |
| CN100377287C (en) | A fluorescent lamp and its manufacturing method | |
| US5680000A (en) | Reflective metal heat shield for metal halide lamps | |
| JP2001357818A (en) | Discharge lamp bulb and its manufacturing method | |
| US4158153A (en) | Low voltage fluorescent lamp having a plurality of cathode means | |
| JPH04277462A (en) | Low-voltage mercury-vapor discharge lamp | |
| GB2110869A (en) | Low pressure sodium vapour discharge lamp | |
| US3325662A (en) | Metal vapor lamp having a heat reflecting coating of calcium pyrophosphate | |
| JP2001527695A (en) | Method of manufacturing low pressure mercury discharge lamp | |
| JP3861557B2 (en) | Fluorescent lamp | |
| US6781303B2 (en) | Mercury vapor lamp amalgam target | |
| JP2002298729A (en) | Ring fluorescent lamps and lighting equipment | |
| JP3211612B2 (en) | Discharge lamp and method of manufacturing the same | |
| EP0838833A2 (en) | Preform for fluorescent lamp, fluorescent lamp prepared by the same, and method for preparing the fluorescent lamp | |
| US2715691A (en) | Vapor discharge lamp | |
| JPH01102844A (en) | Low pressure mercury vapor discharge lamp | |
| JPH0119226B2 (en) | ||
| JPS5885266A (en) | Glow starter | |
| JP3666001B2 (en) | High pressure steam discharge lamp | |
| JP2000348675A (en) | Fluorescent lamps and lighting devices | |
| JPH04280033A (en) | Manufacture of fluorescent lamp | |
| JPH11283559A (en) | Ring fluorescent lamps and lighting fixtures | |
| JP2003109539A (en) | Metal halide lamps and lighting equipment | |
| JPH0883568A (en) | Sealing method of light emitting substance in metallic vapor light emitting tube and this metallic vapor light emitting tube | |
| JP2000340178A (en) | Metal vapor discharge lamp and method of forming arc tube inner surface protective layer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
| PCNP | Patent ceased through non-payment of renewal fee |