CA2103985A1 - Electrodeless fluorescent lamp configuration - Google Patents
Electrodeless fluorescent lamp configurationInfo
- Publication number
- CA2103985A1 CA2103985A1 CA 2103985 CA2103985A CA2103985A1 CA 2103985 A1 CA2103985 A1 CA 2103985A1 CA 2103985 CA2103985 CA 2103985 CA 2103985 A CA2103985 A CA 2103985A CA 2103985 A1 CA2103985 A1 CA 2103985A1
- Authority
- CA
- Canada
- Prior art keywords
- envelope
- fluorescent lamp
- electrodeless fluorescent
- radio frequency
- height
- 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.)
- Abandoned
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
- H01J65/00—Lamps without any electrode inside the vessel; Lamps with at least one main electrode outside the vessel
- H01J65/04—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels
- H01J65/042—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field
- H01J65/048—Lamps in which a gas filling is excited to luminesce by an external electromagnetic field or by external corpuscular radiation, e.g. for indicating plasma display panels by an external electromagnetic field the field being produced by using an excitation coil
Landscapes
- Physics & Mathematics (AREA)
- Electromagnetism (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Discharge Lamps And Accessories Thereof (AREA)
- Circuit Arrangements For Discharge Lamps (AREA)
- Non-Portable Lighting Devices Or Systems Thereof (AREA)
Abstract
ELECTRODELESS FLUORESCENT LAMP
CONFIGURATION
Abstract An electrodeless fluorescent lamp has an envelope configured to have a height-to-width ratio of less than one. According to one embodiment, the envelope is ellipsoidal. Advantageously, such lamps operate at high efficacies and are useful for replacing incandescent lamps in standard fixtures.
CONFIGURATION
Abstract An electrodeless fluorescent lamp has an envelope configured to have a height-to-width ratio of less than one. According to one embodiment, the envelope is ellipsoidal. Advantageously, such lamps operate at high efficacies and are useful for replacing incandescent lamps in standard fixtures.
Description
3 ~ 8 5 RDnO22'101 ELE~TRODELE~S FLUORE~GENT LAMP
CONFIGURATI~~
Field of the Inven~Qn The present invention relates generally to fluorescent lamps and, more particularly, to a high-efficacy electrodeless fluorescent lamp including an envelope configured to have a height-to-width rati~ of less than one.
Fluorescent lamps generally require lower electrical power to operate than conventional incandescent lamps and are generally more efficient than incandescent lamps on a lumens per Watt basis.
Some fluorescent lamps have therefore been designed to replace incandescent lamps in standard fixtures.
However, the use of fluorescent lamps as -incandescent lamp replacements is limited by the fact that practical fluorescent lamps are generally larger (i.e., longer) than incandescent lamps which produce the same light output.
As a class, electrodeless fluorescent lamps are generally smaller, i.e., shorter, than conventional fluorescent lamps, but are still not as short as desired. Typical electrodeless fluorescent lamps use an envelope with a height greater than or equal to the width. Many envelopes are spherical. By way of illustration, exemplary 2~ 039~5 electrodeless fluorescent lamp configurations are shown in: commonly assigned U.S. Pat. No.
4,017,764 of J.M. Anderson; commonly assigned U.S.
Pat. No. 4,187,447 of V.M. Stout and J.M. Anderson;
and in the advertising brochure distributed by Philips Lighting at the Hanover Fair in April 1991.
For fluorescent lamps in general, there is a well-known trade-off in size versus lamp efficacy. That is, for a given light output, efficacy decreases as lamp size decreases. The reason is that discharge current density and electron density, and hence discharge loss mechanisms, increase as a result of a smaller discharge space.
Accordingly, it is desirable to reduce the size ~more specifically, the height) of an electrodeless fluorescent lamp without sacrificing efficacy.
Summ~y of the lnvention An electrodeless fluorescent lamp has an envelope configured to have a height-to-width ratio of less than one. According to one embodiment, the envelope is ellipsoidal. Advantageously, electrodeless fluorescent lamps configured in accordance herewith operate at higher efficacies than incandescent lamps and are useful for replacing such lamps in standard fixtures.
21~398~
~D0~2101 e Drawi~
The features and advantages of the present invention will become apparent from the following detailed description o~ the invention when read with the accompanying drawings in which:
Figure l is a partial sectional view of an electrodeless fluorescent lamp envelope of the prior art;
Figure 2 is a partial sectional view of an electrodeless fluorescent lamp envelope of the present invention; and Figure 3 is a graphical comparison of lS average arc e~ficacy for standard spherical electrodeless fluorescent lamp envelopes and electrodeless fluorescent lamp envelopes according to the present invention, each lamp envelope having the same diameter.
~etailed ~escriptiQn of the I~vention Figure l illustrates a typical electrodeless fluorescent lamp lO having a spherical bulb or envelope 12 containing an ionizable gaseous fill. A suitable fill, for example, comprises a mixture of a rare gas (e.g., krypton and/or argon) and mercury vapor and/or cadmium vapor. An induction transformer core 19 having a winding 16 thereon is situated within a -, 'i , -. :. , .: . ':. : 1:, ':',: ' ,~ , . , ': , ' ' . , ' .
q re-entrant cavity within envelope 12. (However, i~
is to be understood that some fluorescent lamps do not employ a transformer core, and the principles of the invention apply equally to such lamps.) The interior surfaces of envelope 12 are coated in well-known fashion with a suitable phosphor which is stimulated to emit visible radiation upon absorption of ultraviolet radiation. Envelope 12 fits into one end of a base assembly (not shown) containing a radio frequency power supply with a standard incandescent lamp base at the other end.
In operation, current flows through winding 16, establishing a radio frequency magnetic field in transformer core 14. The magnetic field within transformer core 14 induces an electric field within envelope 12 which ionizes and excites the gas contained therein, resulting in an discharge 18. Ultraviolet radiation from discharge 18 is absorbed by the phosphor coating on the interior surface of the envelope, thereby stimulating the emission of visible radiation by the lamp envelope.
Disadvantageously, for a lamp with a spherical envelope such as that shown in Figure 1, there is a trade-off between height versus lamp efficacy. That is, for a lamp having a spherical ; envelope, to decrease the envelope height, the diameter of the envelope must be decreased, leading to lower efficacy. For example, an electrodeless , :
: . . .- . -, .. .. . .. ....... , ~. ,.. ,,,; , .,"",",, , ,.,, . ,,,.. ,;~ .", "., , . ", "
: ~ : : .: : - :: . : :,:: . ., ., ,.,. ~,, ,, ,:; .. :: . ,, .: . ...
' ':: ,i ;J. ~ '';!; :.. .
' ,-.' : '' ' ':' . '. , . ~ ;, :, , . ' . . ':; ' ''j:'~:, ':', ': ,' ::: : ':.,: '' ' ' '. : ' ' ' ;!: ' '` ' , : ' ' ' ' : , :: : . , " . . : ! ,. : . ; . .: . . . , :;: . . . : : . . . , ~ . . . .
21~3~85 - ~D0022101 lamp having a sphe-ical envelope with a 68 mm diameter and producing 1300 lumens is known to have a lower efficacy than a lamp constructed with a spherical envelope with 80 mm diameter also producing 1300 lumens.
In accordance with the present invention, Figure 2 illustrates an electrodeless fluorescent lamp 20 having an envelope with a height-to-width ratio of less than one. Since the top and bottom portions of the envelope have very low discharge density, these portions of the envelope can be substantially reduced in size according to the present invention without creating the increase in current density that would otherwise decrease the lamp efficacy. In particular, the fluorescent lamp of Figure 2 comprises an envelope 22 having an ellipsoidal (or "flattened spherical") shape.
preferred height-to-width ratio is in the range from approximately 0.5 to approximately 0.9.
Advantageously, the shortened configuration of such fluorescent lamps, without sacrificing efficacy, render them as desirable replacements for incandescent lamps in standard base assemblies.
~x~mple Two spherical electrodeless fluorescent ^~
lamp envelopes, each having an outer diameter of 80 mm, and two ellipsoidal electrodeless fluorescent lamp envelopes, each being 80 mm high by 70 mm wide, were constructed. Each lamp envelope was ; ` ;~
21~3~5 ~0v22~D1 dosed with mercury and 0.5 Torr of krypton; and was operated with an air core transformer. At five arc power levels, from 15 Watts to 35 Watts, each lamp envelope was allowed to warm up through its optimum mercury temperature. Peak lumen output and power output were measured at each arc power level, and peak efficacy was measured. A graph of average peak efficacy versus arc power for each pair of lamp envelopes is illustrated in Figure 3, the solid line representing average efficacy of the standard spherical lamp envelopes and the dashed line representing average efficacy of the ellipsoidal lamp envelopes.
Advantageously, as indicated by the data of Figure 3, the efficacy of an electrodeless fluorescent lamp is not sacrificed (and may even be improved) by configuring the lamp envelope according to the present invention, resulting in a small, high-efficacy replacement for incandescent lamps in standard fixtures. Specifically, lamp efficacy is not sacrificed by the shortened envelope configuration because current density is not increased.
While the preferred embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those of skill in the art without departing from ,~ .
2~3~8~
the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended olaims.
.- . . ~.: .. , , . : ,~ ,. ., .... : ,, :, ,.. ;. : .
, , . . ~ ~ ' , : ' . .: ! : ' , : '
CONFIGURATI~~
Field of the Inven~Qn The present invention relates generally to fluorescent lamps and, more particularly, to a high-efficacy electrodeless fluorescent lamp including an envelope configured to have a height-to-width rati~ of less than one.
Fluorescent lamps generally require lower electrical power to operate than conventional incandescent lamps and are generally more efficient than incandescent lamps on a lumens per Watt basis.
Some fluorescent lamps have therefore been designed to replace incandescent lamps in standard fixtures.
However, the use of fluorescent lamps as -incandescent lamp replacements is limited by the fact that practical fluorescent lamps are generally larger (i.e., longer) than incandescent lamps which produce the same light output.
As a class, electrodeless fluorescent lamps are generally smaller, i.e., shorter, than conventional fluorescent lamps, but are still not as short as desired. Typical electrodeless fluorescent lamps use an envelope with a height greater than or equal to the width. Many envelopes are spherical. By way of illustration, exemplary 2~ 039~5 electrodeless fluorescent lamp configurations are shown in: commonly assigned U.S. Pat. No.
4,017,764 of J.M. Anderson; commonly assigned U.S.
Pat. No. 4,187,447 of V.M. Stout and J.M. Anderson;
and in the advertising brochure distributed by Philips Lighting at the Hanover Fair in April 1991.
For fluorescent lamps in general, there is a well-known trade-off in size versus lamp efficacy. That is, for a given light output, efficacy decreases as lamp size decreases. The reason is that discharge current density and electron density, and hence discharge loss mechanisms, increase as a result of a smaller discharge space.
Accordingly, it is desirable to reduce the size ~more specifically, the height) of an electrodeless fluorescent lamp without sacrificing efficacy.
Summ~y of the lnvention An electrodeless fluorescent lamp has an envelope configured to have a height-to-width ratio of less than one. According to one embodiment, the envelope is ellipsoidal. Advantageously, electrodeless fluorescent lamps configured in accordance herewith operate at higher efficacies than incandescent lamps and are useful for replacing such lamps in standard fixtures.
21~398~
~D0~2101 e Drawi~
The features and advantages of the present invention will become apparent from the following detailed description o~ the invention when read with the accompanying drawings in which:
Figure l is a partial sectional view of an electrodeless fluorescent lamp envelope of the prior art;
Figure 2 is a partial sectional view of an electrodeless fluorescent lamp envelope of the present invention; and Figure 3 is a graphical comparison of lS average arc e~ficacy for standard spherical electrodeless fluorescent lamp envelopes and electrodeless fluorescent lamp envelopes according to the present invention, each lamp envelope having the same diameter.
~etailed ~escriptiQn of the I~vention Figure l illustrates a typical electrodeless fluorescent lamp lO having a spherical bulb or envelope 12 containing an ionizable gaseous fill. A suitable fill, for example, comprises a mixture of a rare gas (e.g., krypton and/or argon) and mercury vapor and/or cadmium vapor. An induction transformer core 19 having a winding 16 thereon is situated within a -, 'i , -. :. , .: . ':. : 1:, ':',: ' ,~ , . , ': , ' ' . , ' .
q re-entrant cavity within envelope 12. (However, i~
is to be understood that some fluorescent lamps do not employ a transformer core, and the principles of the invention apply equally to such lamps.) The interior surfaces of envelope 12 are coated in well-known fashion with a suitable phosphor which is stimulated to emit visible radiation upon absorption of ultraviolet radiation. Envelope 12 fits into one end of a base assembly (not shown) containing a radio frequency power supply with a standard incandescent lamp base at the other end.
In operation, current flows through winding 16, establishing a radio frequency magnetic field in transformer core 14. The magnetic field within transformer core 14 induces an electric field within envelope 12 which ionizes and excites the gas contained therein, resulting in an discharge 18. Ultraviolet radiation from discharge 18 is absorbed by the phosphor coating on the interior surface of the envelope, thereby stimulating the emission of visible radiation by the lamp envelope.
Disadvantageously, for a lamp with a spherical envelope such as that shown in Figure 1, there is a trade-off between height versus lamp efficacy. That is, for a lamp having a spherical ; envelope, to decrease the envelope height, the diameter of the envelope must be decreased, leading to lower efficacy. For example, an electrodeless , :
: . . .- . -, .. .. . .. ....... , ~. ,.. ,,,; , .,"",",, , ,.,, . ,,,.. ,;~ .", "., , . ", "
: ~ : : .: : - :: . : :,:: . ., ., ,.,. ~,, ,, ,:; .. :: . ,, .: . ...
' ':: ,i ;J. ~ '';!; :.. .
' ,-.' : '' ' ':' . '. , . ~ ;, :, , . ' . . ':; ' ''j:'~:, ':', ': ,' ::: : ':.,: '' ' ' '. : ' ' ' ;!: ' '` ' , : ' ' ' ' : , :: : . , " . . : ! ,. : . ; . .: . . . , :;: . . . : : . . . , ~ . . . .
21~3~85 - ~D0022101 lamp having a sphe-ical envelope with a 68 mm diameter and producing 1300 lumens is known to have a lower efficacy than a lamp constructed with a spherical envelope with 80 mm diameter also producing 1300 lumens.
In accordance with the present invention, Figure 2 illustrates an electrodeless fluorescent lamp 20 having an envelope with a height-to-width ratio of less than one. Since the top and bottom portions of the envelope have very low discharge density, these portions of the envelope can be substantially reduced in size according to the present invention without creating the increase in current density that would otherwise decrease the lamp efficacy. In particular, the fluorescent lamp of Figure 2 comprises an envelope 22 having an ellipsoidal (or "flattened spherical") shape.
preferred height-to-width ratio is in the range from approximately 0.5 to approximately 0.9.
Advantageously, the shortened configuration of such fluorescent lamps, without sacrificing efficacy, render them as desirable replacements for incandescent lamps in standard base assemblies.
~x~mple Two spherical electrodeless fluorescent ^~
lamp envelopes, each having an outer diameter of 80 mm, and two ellipsoidal electrodeless fluorescent lamp envelopes, each being 80 mm high by 70 mm wide, were constructed. Each lamp envelope was ; ` ;~
21~3~5 ~0v22~D1 dosed with mercury and 0.5 Torr of krypton; and was operated with an air core transformer. At five arc power levels, from 15 Watts to 35 Watts, each lamp envelope was allowed to warm up through its optimum mercury temperature. Peak lumen output and power output were measured at each arc power level, and peak efficacy was measured. A graph of average peak efficacy versus arc power for each pair of lamp envelopes is illustrated in Figure 3, the solid line representing average efficacy of the standard spherical lamp envelopes and the dashed line representing average efficacy of the ellipsoidal lamp envelopes.
Advantageously, as indicated by the data of Figure 3, the efficacy of an electrodeless fluorescent lamp is not sacrificed (and may even be improved) by configuring the lamp envelope according to the present invention, resulting in a small, high-efficacy replacement for incandescent lamps in standard fixtures. Specifically, lamp efficacy is not sacrificed by the shortened envelope configuration because current density is not increased.
While the preferred embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions will occur to those of skill in the art without departing from ,~ .
2~3~8~
the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended olaims.
.- . . ~.: .. , , . : ,~ ,. ., .... : ,, :, ,.. ;. : .
, , . . ~ ~ ' , : ' . .: ! : ' , : '
Claims (8)
1. An electrodeless fluorescent lamp, comprising:
a light-transmissive envelope having an interior phosphor coating for emitting visible radiation when excited by ultraviolet radiation, said envelope having a height-to-width ratio of less than one;
a magnetic core contained within said envelope;
means for establishing a radio frequency magnetic field in said core; and an ionizable, gaseous fill contained in said envelope for sustaining an arc discharge when subjected to said radio frequency magnetic field and to emit ultraviolet radiation as a result thereof.
a light-transmissive envelope having an interior phosphor coating for emitting visible radiation when excited by ultraviolet radiation, said envelope having a height-to-width ratio of less than one;
a magnetic core contained within said envelope;
means for establishing a radio frequency magnetic field in said core; and an ionizable, gaseous fill contained in said envelope for sustaining an arc discharge when subjected to said radio frequency magnetic field and to emit ultraviolet radiation as a result thereof.
2. The electrodeless fluorescent lamp of claim 1 wherein said envelope is substantially ellipsoidal.
3. The electrodeless fluorescent lamp of claim 1 wherein the height-to-width ratio is in the range from approximately 0.5 to approximately 0.9.
4. The electrodeless fluorescent lamp of claim 1 wherein said means for establishing a radio frequency magnetic field comprises a drive coil wound about said core.
5. An electrodeless fluorescent lamp, comprising:
a light-transmissive envelope having an interior phosphor coating for emitting visible radiation when excited by ultraviolet radiation, said envelope having a height-to-width ratio of less than one;
a drive coil situated within said envelope;
means for coupling a radio frequency supply to said drive coil so as to generate a radio frequency magnetic field about said coil; and an ionizable, gaseous fill contained in said envelope for sustaining an arc discharge when subjected to said radio frequency magnetic field and to emit ultraviolet radiation as a result thereof.
a light-transmissive envelope having an interior phosphor coating for emitting visible radiation when excited by ultraviolet radiation, said envelope having a height-to-width ratio of less than one;
a drive coil situated within said envelope;
means for coupling a radio frequency supply to said drive coil so as to generate a radio frequency magnetic field about said coil; and an ionizable, gaseous fill contained in said envelope for sustaining an arc discharge when subjected to said radio frequency magnetic field and to emit ultraviolet radiation as a result thereof.
6. The electrodeless fluorescent lamp of claim 5 wherein said envelope is substantially ellipsoidal.
7. The electrodeless fluorescent lamp of claim 5 wherein the height-to-width ratio is in the range from approximately 0.5 to approximately 0.9.
8. The invention as defined in any of the preceding claims including any further features of novelty disclosed.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US93708392A | 1992-08-31 | 1992-08-31 | |
| US937,083 | 1992-08-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2103985A1 true CA2103985A1 (en) | 1994-03-01 |
Family
ID=25469474
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2103985 Abandoned CA2103985A1 (en) | 1992-08-31 | 1993-08-12 | Electrodeless fluorescent lamp configuration |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0586180A1 (en) |
| JP (1) | JPH06196133A (en) |
| CA (1) | CA2103985A1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5959405A (en) * | 1996-11-08 | 1999-09-28 | General Electric Company | Electrodeless fluorescent lamp |
| DE102005050306B3 (en) * | 2005-10-20 | 2007-03-15 | Minebea Co., Ltd. | Electrode-less high frequency low-pressure gas discharge lamp has soft magnetic core for inductive conversion with exciter winding and discharge unit |
| US8896191B2 (en) | 2011-07-11 | 2014-11-25 | Osram Sylvania Inc. | Mercury-free discharge lamp |
| US8994288B2 (en) | 2013-03-07 | 2015-03-31 | Osram Sylvania Inc. | Pulse-excited mercury-free lamp system |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5454473A (en) * | 1977-10-08 | 1979-04-28 | Toshiba Corp | No-electrode discharge lamp |
| SU1156168A1 (en) * | 1983-11-21 | 1985-05-15 | Всесоюзный Научно-Исследовательский,Проектно-Конструкторский И Технологический Светотехнический Институт | Electrodeless luminiscent lamp |
| NL8500736A (en) * | 1985-03-14 | 1986-10-01 | Philips Nv | ELECTRESSLESS LOW PRESSURE DISCHARGE LAMP. |
-
1993
- 1993-08-12 CA CA 2103985 patent/CA2103985A1/en not_active Abandoned
- 1993-08-24 EP EP93306713A patent/EP0586180A1/en not_active Withdrawn
- 1993-08-26 JP JP21112093A patent/JPH06196133A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| JPH06196133A (en) | 1994-07-15 |
| EP0586180A1 (en) | 1994-03-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |