CA1187927A - Discharge lamp and lighting equipment - Google Patents
Discharge lamp and lighting equipmentInfo
- Publication number
- CA1187927A CA1187927A CA000357788A CA357788A CA1187927A CA 1187927 A CA1187927 A CA 1187927A CA 000357788 A CA000357788 A CA 000357788A CA 357788 A CA357788 A CA 357788A CA 1187927 A CA1187927 A CA 1187927A
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- CA
- Canada
- Prior art keywords
- arc tube
- high pressure
- pressure arc
- discharge
- low pressure
- 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.)
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- Circuit Arrangements For Discharge Lamps (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE:
A discharge lamp comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure discharge which is electrically connected in parallel to said high pressure arc tube in an outer bulb.
A lighting equipment comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pre-ssure discharge which is electrically connected in parallel to said high pressure arc tube; and a high frequency ballast having 1 kHz to 100 KHz for operating the said high pressure and low pressure arc tubes.
A discharge lamp comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure discharge which is electrically connected in parallel to said high pressure arc tube in an outer bulb.
A lighting equipment comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pre-ssure discharge which is electrically connected in parallel to said high pressure arc tube; and a high frequency ballast having 1 kHz to 100 KHz for operating the said high pressure and low pressure arc tubes.
Description
~'7~ZJ~
l 4~,921 _CKGROUND OF T~E I~ENTION:
FIEID O~ r~
- The present invention relates to a no~el discharge lamp in which a high pressure arc tu~e for high pressure discharge is electri-cally cons~ected in parallel to a low pressure arc tube for low pressuredischarge and both arc tubes are placed in an outer bulb and a novel lighting equipment which opera-tes the low pressure arc tube and the high pressure arc tube with a high frequency ballast.
DESCRIPTION OF THF. PRIOR ARTS:
In general, a mercury pressure in a high pressure arc tube is about several atm. during the operation of the discharge lamp in a high pressure mercury vapor discharge lamp, a metal halide vapor dischar-ge lamp and a high pressure sodium vapor lamp which have three to ten times the luminous efficacy of an incandescent lamp. Therefore, when the discharge lamp is once inactuated by a temporary power voltage drop or a temporary service in-terruption, the discharge lamp is not able to start immediately even though the power voltage is return-ed to the normal level.
It has been difficult to s-tart the lamp lmtil the temperature in the arc tube is lowered to decrease the mercury vapor pressure in the arc tube to -the level required for the start. The time required for the restart of the discharge is called the restart time which is about 3 to 5 minutes in the high pressure mercury vapor discharge lamp, 8 to 15 minutes in the metal halide vapor discharge lamp and 1 to 2 minutes in the high pressure sodium vapor discharge lamp which is s-tarted with a ballast equipped with a high voltage pulse generator, and
l 4~,921 _CKGROUND OF T~E I~ENTION:
FIEID O~ r~
- The present invention relates to a no~el discharge lamp in which a high pressure arc tu~e for high pressure discharge is electri-cally cons~ected in parallel to a low pressure arc tube for low pressuredischarge and both arc tubes are placed in an outer bulb and a novel lighting equipment which opera-tes the low pressure arc tube and the high pressure arc tube with a high frequency ballast.
DESCRIPTION OF THF. PRIOR ARTS:
In general, a mercury pressure in a high pressure arc tube is about several atm. during the operation of the discharge lamp in a high pressure mercury vapor discharge lamp, a metal halide vapor dischar-ge lamp and a high pressure sodium vapor lamp which have three to ten times the luminous efficacy of an incandescent lamp. Therefore, when the discharge lamp is once inactuated by a temporary power voltage drop or a temporary service in-terruption, the discharge lamp is not able to start immediately even though the power voltage is return-ed to the normal level.
It has been difficult to s-tart the lamp lmtil the temperature in the arc tube is lowered to decrease the mercury vapor pressure in the arc tube to -the level required for the start. The time required for the restart of the discharge is called the restart time which is about 3 to 5 minutes in the high pressure mercury vapor discharge lamp, 8 to 15 minutes in the metal halide vapor discharge lamp and 1 to 2 minutes in the high pressure sodium vapor discharge lamp which is s-tarted with a ballast equipped with a high voltage pulse generator, and
2 to 10 minutes in the high pressure sodium vapor discharge lamp q~
2~
2 ~8~92l which is started with a ballast having no high voltage pulse generator.
Thus, the high pressure discharge lamps which require a long restart period are ncl~ s~isfactory, i~ their uses.
When a ~hïgh ~ressure discharge lamp having high efficacy is consiclered to repl~ce for the iucandescent lamp which is main-ly used as a light source but has a quite low efficacy, the disadvanta geous long restart period should be considered.
.~ ballast is required for operating the high pressure clischarge lamp, and it is large and heavy and accordingly, it is assembled sepa-ra-tely from the discharge lamp. Therefore, it has been impossible to consider the replacement of the incandescent lamp by a combination of the ballast and the discharge lamp.
SU~RY OF THE INVENTION:
It is an object o-E the present invention to overcome the above-mentioned disadvantages and to provide a discharge lamp which is usually operated by a high pressure arc tube and also continues an emission by a discharge caused by a low pressure arc tube during the time from extinction to restart of the high pressure arc tube so as to preven-t the extinction of the discharge lamp.
It is another object of the present invention to provide a light-ing equipment which is compact and has high efficacy and can be used the same as an incandescent lamp.
The foregoing and other objects of the present invention have been attained by providing a discharge lamp which comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure discharge and an outer tube in which the high pressure arc tube is electrically connected in parallel to the low pre-ssure arc tube.
~7~
2~
2 ~8~92l which is started with a ballast having no high voltage pulse generator.
Thus, the high pressure discharge lamps which require a long restart period are ncl~ s~isfactory, i~ their uses.
When a ~hïgh ~ressure discharge lamp having high efficacy is consiclered to repl~ce for the iucandescent lamp which is main-ly used as a light source but has a quite low efficacy, the disadvanta geous long restart period should be considered.
.~ ballast is required for operating the high pressure clischarge lamp, and it is large and heavy and accordingly, it is assembled sepa-ra-tely from the discharge lamp. Therefore, it has been impossible to consider the replacement of the incandescent lamp by a combination of the ballast and the discharge lamp.
SU~RY OF THE INVENTION:
It is an object o-E the present invention to overcome the above-mentioned disadvantages and to provide a discharge lamp which is usually operated by a high pressure arc tube and also continues an emission by a discharge caused by a low pressure arc tube during the time from extinction to restart of the high pressure arc tube so as to preven-t the extinction of the discharge lamp.
It is another object of the present invention to provide a light-ing equipment which is compact and has high efficacy and can be used the same as an incandescent lamp.
The foregoing and other objects of the present invention have been attained by providing a discharge lamp which comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure discharge and an outer tube in which the high pressure arc tube is electrically connected in parallel to the low pre-ssure arc tube.
~7~
3 48,921 ~RIEF DESCRI TION OF THE DRAWINGS:
Fixl~res ~ ~nd 2 show one e~bodiment of the present invention wherein Figure 1 is a front view of a discharge lamp; and Figure 2 is a circuit diagram using the discharge lamp;
E'igures 3 and 4 show the other embodiment wherein Figure 3 is a front view of a lighting equipment and Figure 4 is a circuit diagram using the lighting equipment.
DETAILED DE~CRIPTION OF T~E PREFERRED EMBODIMENTS:
Referring to Figures 1 and 2, one embodiment of the present invention will be illus-trated.
In Figures 1 and 2, the reference numeral (1) designates an outer bulb made of a light transmissable glass having an egg shape which is equipped with a base (2) at one end; (3) designates a support frame having parallel support wires (5),(5) which are held by each pla-te ].5 spring (4),(4) in the outer bulb and the support frame is connected toa stem lead (7) projected from the stem ~6) and is electrically connected to the base (2). The reference numeral (8) designates a high pre-ssure arc tube such as the 400 W metal halide vapor arc tube for high pressure discharge which is held through a pair of support plates (9),(9) 2G to the support wire (5) of the support frame (3). A pair of electrodes(10),(11) are respectively provided at both ends in the sealed tube and one electrode (lO) is electrically connected to the support frame (3), and the other electrode (11) is electrically connected to the stem lead (12) projected -from the stem (6) connected to the base (2).
The reference numeral (13) is a low pressure arc -tube for low pressure discharge which i.s held through a pair of support pla-tes (14),(1~) to the other support wire (5) of the support frame (3) and the low pressure ~7~
1~ 48,921 arc tube has a pair of ele~tr~des ~15~,[16) at each end, and has an inner diameter of 6 mm and a distance between the electrodes (15),(16) of 20 mm and contains a mixed gas consisting of 99/O o~
neon and 1% ol argon under a pressure of 10 torr.
- One electrode (15) of the low pressure arc tube (13) is elect-rically connected to the support frame (3) and the other electrode (16) is electrically connected through an impedance elemen-t (17) such as a resi.stor having 180 (~3 to the stem lead (12). That is, the series co-nnection of the low pressure arc tube (13) and the impedance element (17) is connected in parallel to the high pressure arc tube and these elements are placed in the outer bulb (1).
As shown in Figure 2, the discharge lamp having said struc-ture is connected through a ballast (18) to a power source (19).
When the power voltage is applied, the discharge of the high pressure arc tube (8) starts and a current controlled by the bal.last (18) is fed and the high pressure arc tube (8) is in the stable state about 5 minutes after the discharge start. Sometimes, the discharge of the low pre-ssure arc tube (13) simultaneously starts for a moment when the dischar-ge of the high pressure arc tube (8) is star-ted. }lowever, an impedance element (17) having a relatively high impedance such as 180 ~ (resistor) is connected in series to the low pressure arc tube (13) so as to control the current passing through the low pressure arc tube (13) to about 1 Amp. When the arc current having 5 to 6 Amp. is passed through the high pressure arc tube in the starting period, the voltage between the electrodes (10), (11) of the high pressure arc tube (8) is decreased to 20 to 30 vol.t, and the voltage between the electrodes (15),(16) of the low pressure arc tube (13) is decreased whereby the discharge of the low pressure arc tube (13) is stopped and only discharge of the high pressure arc tube (8) continues.
~8,921 In the stable state of the high pressure arc tube (8), a current havi~g ~ o ~ . is passed throu$h the circuit of the base (2)- stem lead ~l~)-electrode ~ -e~ectrode ~ support frame ~3)-stem lead (7)-base (2) to -the ballast, however any current is not passed through the circuit of the low pressure arc tube (13) and the impedance element 117) and the high pressure arc tube (8) maintains the stable state and the low pressure arc tube (13) is kept in the non~discharge state.
When the high pressure arc tube (8) is extinguished from the stable state by a temporary voltage d:rop of the power voltage, even though the power voltage is returned to the normal level, the pressure in the high pressure arc tube (8) is high as several atm. whereby the discharge of the high pressure arc tube (8) is not capable of the start.
Thus, when the power voltage is applied to the high pressure arc tube (8) in the state of incapable of the start, the low pressure arc tube (13) is capable of the start. Therefore, the low pressure arc tube (13) is immediately started when the high pressure arc tube (8) is extinguished.
The lighting is continued by the low pressure arc tube (13). Therefore, the discharge lamp continues light emission corresponding to the light emission character:istics of the low pressure arc tube (13) without causing a complete inactuation of the discharge lamp. In this condition, a current of 1 Amp. controlled by the impedance elemen-t (17) is passed through the circuit of the base (2)-stem lead (12)-impedance element (17)-electrode (16)-electrode (15)-support frame (3)-stem lead (7)-base (2) to the ballast (18), whereas any current is not passed through the high pressure arc tube (8).
When the temperature of the high pressure arc tube (8) is decreased under the condition of the actuation of -the low pressure arc tube (13), and the mercury vapor pressure in the arc tube is decreased to be capable of -the start of the discharge, the discharge of the high pressure arc tube (8) is started again and the stable state is given after 5 minutes and the light emission having desired elec-trical and optical %~
6 ~i8,921 characteristics is continued. In this e~m~lle, ~he time required for the resta~ ~i the discha~e of the high pressure arc tube (8) is about 10 minutes. When tbe disc~arge of t~ne high pressure arc tube (8) is started again, the discharge of the low pressure arc tube (13) is stopp-ed because of the sar~e i:unctiorl at the start of the discharge lamp.
Therefore, the low pressure arc tube (13) is not actuated during the actuation of the high pressure arc tube (8).
In said embodiment, the impedance element (17) is connected in series to the low pressure arc tube (13). When the glow discharge is continued in the state applying the power voltage to the low pressure arc tube (13), it is possible to eliminate the impedance element (17) only by the parallel connection of the low pressure arc tube (13) and the high pressure arc tube (8).
In said emebodiment, 400 W metal halide arc tube is used as the high pressure arc tube (8). Thus, it is not limited to use a 400 W
arc tube and it is possible to use arc tubes for high pressure mercury vapor discharge lamps and high pressure sodium vapor discharge lamps, etc. The arc -tube containing the mixed gas of neon and argon is used as the low pressure arc tube. Thus, it is possible to use an arc tube for low pressure mercury vapor discharge lamps, a fluorescent lamp or a rare gas discharge lamp. The pressure of the sealed gas in the low pressure arc tube (13) is preferably lower than 100 torr so as to start the discharge by the normal voltage. Thus, these lamps can be used.
In said embodiment, the resistor is used as the impedance element (17) connected in series to the low pressure arc -tube (13).
Thus, it is possible to use a capacitor, a choke coil, a filament coil or a combination of two or more of the capacitor, the choke coil, and the filament coil or the resistor as the impedance element.
The impedance of the impedance element (17) can be select-ed as desired depending upon the characteristic of the low pressure 7 ~8~921 arc tube (13).
When a filament coil is used as the impedance element (17), cer~ain light emission from the Eilament coil is given to make bright dur:ing ~ ac~llati~ of the low pressure arc tube ~13) beEore the restart of the high pressure arc tube (8~.
~ igures 3 and 4 show the other embodiment of the present invention wherein the reference numeral (20) designates a lighting equip-ment comprising a light transmiscible outer bulb (1), the high frequen-cy ballast (18) and a base (2). In the outer bulb (1), a high pressure arc tube (8), a tungsten filament (17) and a low pressure arc tube (13) are placed. The high pressure arc tube (8) has electrodes (10),(11) at each end, and one electrode (10) is connected to a support lead (3) and the other electrode (11) is connected to a lead (12) of the ballast (18). The support lead (3) is connected to the other lead (7) oE the ballast (18). The low pressure arc tube (13) has elec-trodes (15), (16) at each end, and one electrode 15 .is connected through the tungs-ten filament (17) to the support lead (3) and the electrode (16) is connected to the lead (12). Therefore, the low pressure arc tube (13) connec-ted in series to the filament (17) is electrically connected in parallel to the high pressure arc tube (8). The lead oE the ballast (18) at the power source side is connected to the base (2).
The high pressure arc tube (8) can be a 30 ~ metal halide arc -tube in which mercury, argon and scandium halide and sodiwD halide are filled in the sealed condition. The low pressure arc tube (13) can be a rare gas arc tube having an inner diameter of 5 mm and a distance between the electrodes (15),(16) of 10 mm and contains a mi~ed gas consisting of 99% of neon and 1% of argon under the pressure of 20 torr. The impedance element can be a tungsten filament (17) hav-ing 400 n for controlling the current in the low pressure arc tube (13) to 0.~ Amp. A inert gas is filled in the outer tube (1) so as -to prevent ~7~2~
~ 48,921 the ~Japorizati~n of tungsten from the filament and to prevent the oxida-tion of Lhe el~e~s plac~ iD ~he o~ter hulb.
~he lighting ~e~iipment having said structure is connected to the power source (19) as shown in Figure 4 whereby the high frequency voltage generated by the high frequency ballast (1~) is applied to the arc tube and the discharge of the high pressure arc tube (8) is started to pass the current controlled by the ballast ~18) through the high pressure arc tube (8).
The high pressure arc tube (8) reaches to the stable state about 3 minutes after the start of the discharge. When the discharge of the high pressure arc tube (8) is started, sometimes, the discharge of the low pressure arc tube (13) is simultaneously started for a moment.
A filament having relatively high resistance of 400 Q is conne-cted as the i.mpedance element (17) (resistor) to the low pressure arc tube (13). 'rherefore, the current passing through the low pressure arc tube is limited to 0.2 Amp. When the arc discharge current of 0.6 to 0.65 ~np. is passed through the high pressure arc tube at the start, the vol.tage applied between the electrodes (10),(11) of the high pressure arc tube (8) is decreased to about 20 Volt, and -the voltage applied bet-ween the electrodes of the low pressure arc tube (13) is lowered to stop the discharge in the low pressure arc tube (13) and only the high pre-ssure arc tube (8) continues the discharge.
In the stable sta-te of the high pressure arc tube (8), the current is passed through the circuit of the base (2)-ballast (18)-lead (7)-support lead (3)-electrode (10)-electrode (11)-lead (12)-ballast (18)-base (2) whereas any current is not passed through the low pressure arc tube (13) and an impedance element (17) whereby the high pressure arc tube (8) maintains the stable state whereas the low pressure arc tube (13) continues the non-discharge state.
9 ~18,92:1 ~he~ the high pressure arc tube (8) is extinguished from the sta'ble s~ate ~S~ ca te~pc,r~ry voltage drop of the po~er voltage, even though ~he power ~ol~ge is -leturned to the normal level, the pressure in the high pressure arc ~ube ~) is high as several atm. whereby the discharge o~ the high pressure arc tube (8) i.s not capable oE -the start.
Thus, when the power voltage is applied to the high pressure arc tube (8) in the state of incapable of the start, the low pressure arc tube (13) is capable of -the start. Therefore, the 1.ow pressure arc tube 113) is immediately star-ted when the high pressure arc tube (8) is extinguished.
The lighti.ng is continued by the low pressure arc tube (13) and the tungsten ~ilament (17). Therefore, the discharge lamp continues light emission corresponding to the light emission characteristics of the low pressure arc tube (13) and the tungsten filament (l73 without caus-ing a comple~e inactuation of the discharge lamp.
During the state, the high frequency current. of 0.2 Amp.
which is controlled by the filament (17) as the impedance element is passed through the circuit of the base (2)-ballast (18)-lead (7)-support lead (3)-filament (17) as the impedance e:lement-electrode (15)-electrode (16)-lead (12)-ballast (18)-base (2) whereas any current is passed through the high pressure arc tube (8).
When the temperature of the high pressure arc tube (8) is decreased under the condition of the operation of the low pressure arc tube (13) and the mercury vapor pressure in the arc tube is decreased to be capable of the start of the discharge, the discharge of the high pressure arc -tube (8) is started again and the stable state is given after 3 minutes, and the light emission having desired electrical and optical characteristics is continued. In this example, the time required for the restart of the discharge of the high pressure arc tube (8) is about 8 minutes. When the discharge of the high pressure arc tube (8) is started again, the discharge of the low pressure arc tube (13) is stopp-ed because of the same function at the start of the discharge lamp.
lO 4~,921 Therefore, the low pressure arc tube (13) is not actuated during the act~ation of the high pressure arc tube ~8).
The charac-teri~-ti~ oi the ~ighting equipment having the arc tube ~:f-the 30 ~ ~t~ a.ide ~apor discharge lamp and the characteris tics of lO0 W incandescent lamp are shown in Table 1.
As it is clear from the data of Table l, the lighting equipment o-l this example of the present invention has three -times of the effic~acy of the incandescent lamp and five times of the life of the incandescent lamp.
The luminous efficacy in Table I means efficacy of only the lamp as to-tal luminous flux/lamp power and the overall efficacy means total efficacy of the lamp and the ballast as total luminous flux/inpu-t power.
The 30 W metal halide vapor discharge lamp of -this embodi ment is operated by the high frequency current having 20 KH~ and accordingly, the loss caused by the ballast is smaller than that of the conventional discharge lamp and the inpu-t power is 34 W.
~ 8,921 Table 1 ._ _ _ Type ~ 100 W Light:ing equipment incandescent lalr~p having 30 W metal halide arc tube _.___ __.___ _ __ , _ Power of lamp 100 30 (Watt) ~oltage of lamp _ 60 (Volt) Current of lamp _ 0.56 (Amp.) Total luminous flux 1520 1500 Luminous efficacy 15.2 50 _ _ _ ___ ( lm ) __ __ _ I,i-fe (hr.) 1000 5000 In the embodiment shown in Figures 3 and 4, the tungsten filament as the impedance element (17) is connected to the low pressure arc tube (13). When the glow discharge is continued in the state apply-ing the power voltage to the low pressure arc tube (13), it is possible -to elimina-te the impedance element (17) only the parallel connection of the low pressure arc tube (13) and the high pressure arc tube (8).
In said embodiment, 30 W metal halide arc tube is used as the high pressure arc tube (8). Thus, it is not limited to use a 30 W
arc tube and it is possible to use arc tubes -for high pressure mercury vapor discharge lamps and high pressure sodium vapor discharge lamps, etc. The arc tube containing the mixed gas of neon and argon is used '7~
~ 48,921 as the low pressure arc tube. Thus, it i~ possi~le to use an arc tube Eor low pressure mercury vapor discharge lamps, a fluorescent lamp or a rare gas discharge lamp.
The pressure of the sealed gas in the low pressure arc tube (13)-is preferably lower than 100 torr so as to start the discharge by the norma]. voltage. Thus, these lamps can be used.
ln said embodiment, the resistor is used as the impedance element (17) connected in series to the low pressure arc tube (13).
Thus, it is possi.ble to use a capacitor, a choke coil, a filament coil, or a combination of two or more of the capacitor, the choke coil, and the filament coil or the resistor as the impedance element.
The impedance of the impedance element (17) can be select-ed as desired depending upon the characteristic of the low pressure arc tube (13).
~hen a filament coil is used as the impedance element (17), certain light emission from the filament coil is givell to make hright during the actua-tion of the low pressure arc tube (13) before the res-tart of the high pressure arc tube (8).
In said embodiment shown in Figures 3 and ~1, the frequency of the voltage and the current for the operating the arc tube (8) or (13) by generating from the high frequency ballast (18) is 20 KHz.
Thus, it is preferable to use the frequency ranging from 1 K}lz to 100 KHz. When the frequency is less than 1 KHz, the compact and light weight of the ballast are not satisfactory. When the frequency is greater than 100 KHz, the extinction phenomenon caused by unstable discharge in the xepeated starting of the high pressure arc tube (13) is took p].ace, and this is serious disadvantage in the practical use.
In accordance with the present invention, the high pressure arc tube for high pressure discharge is electrically connected in parall-el to the low pressure arc tube for low pressure discharge and botharc tubes are placed in the outer bulb whereby the discharge lamp is 13 48,92l usually opera~e~l by the high pressur~ ar~ -tube having high efficacy and when the high ~-~e~ re arc tu~e is e~i.nguished by c~rt~in factor, the low pressure arc tube i~ ~ctuated duri.ng the period ~rom the extinction to the restart of the high pressure arc tube to prevent the complete inactuation of the discharge lamp ancl to prevent complete darkness of the lighting part. The discharge lamp having remarkable advantages can be obtained.
~ en the high pressure arc tube for high pressure discharge is electrical.ly connected in parallel -to the low pressure arc tube for low pressure ~ischarge and both arc tubes are placed in the outer bulb and are operated by the high frequency ballast having 1 ~Iz to 100 KHz, the discharge lamp is usually operated by the high pressure arc tube having high efficacy and when the high pressure arc tube is extinguished b~) certain factor, the low pressure arc tube is actuated during the period from the extinction to the restart of the high pressure arc tube to prevent the complete inac-tuation of the discharge lamp and to prevent complete darkness of the lighting part. Moreover, the ballast can be compact -to be capable of a combination arc tubes and the ~allast as assembled :in one discharge lamp which can be used to replace for the incandescent lamp in the lighti.ng equipment.
The lighting equipment having remarkab].e advantages can be obtained.
Fixl~res ~ ~nd 2 show one e~bodiment of the present invention wherein Figure 1 is a front view of a discharge lamp; and Figure 2 is a circuit diagram using the discharge lamp;
E'igures 3 and 4 show the other embodiment wherein Figure 3 is a front view of a lighting equipment and Figure 4 is a circuit diagram using the lighting equipment.
DETAILED DE~CRIPTION OF T~E PREFERRED EMBODIMENTS:
Referring to Figures 1 and 2, one embodiment of the present invention will be illus-trated.
In Figures 1 and 2, the reference numeral (1) designates an outer bulb made of a light transmissable glass having an egg shape which is equipped with a base (2) at one end; (3) designates a support frame having parallel support wires (5),(5) which are held by each pla-te ].5 spring (4),(4) in the outer bulb and the support frame is connected toa stem lead (7) projected from the stem ~6) and is electrically connected to the base (2). The reference numeral (8) designates a high pre-ssure arc tube such as the 400 W metal halide vapor arc tube for high pressure discharge which is held through a pair of support plates (9),(9) 2G to the support wire (5) of the support frame (3). A pair of electrodes(10),(11) are respectively provided at both ends in the sealed tube and one electrode (lO) is electrically connected to the support frame (3), and the other electrode (11) is electrically connected to the stem lead (12) projected -from the stem (6) connected to the base (2).
The reference numeral (13) is a low pressure arc -tube for low pressure discharge which i.s held through a pair of support pla-tes (14),(1~) to the other support wire (5) of the support frame (3) and the low pressure ~7~
1~ 48,921 arc tube has a pair of ele~tr~des ~15~,[16) at each end, and has an inner diameter of 6 mm and a distance between the electrodes (15),(16) of 20 mm and contains a mixed gas consisting of 99/O o~
neon and 1% ol argon under a pressure of 10 torr.
- One electrode (15) of the low pressure arc tube (13) is elect-rically connected to the support frame (3) and the other electrode (16) is electrically connected through an impedance elemen-t (17) such as a resi.stor having 180 (~3 to the stem lead (12). That is, the series co-nnection of the low pressure arc tube (13) and the impedance element (17) is connected in parallel to the high pressure arc tube and these elements are placed in the outer bulb (1).
As shown in Figure 2, the discharge lamp having said struc-ture is connected through a ballast (18) to a power source (19).
When the power voltage is applied, the discharge of the high pressure arc tube (8) starts and a current controlled by the bal.last (18) is fed and the high pressure arc tube (8) is in the stable state about 5 minutes after the discharge start. Sometimes, the discharge of the low pre-ssure arc tube (13) simultaneously starts for a moment when the dischar-ge of the high pressure arc tube (8) is star-ted. }lowever, an impedance element (17) having a relatively high impedance such as 180 ~ (resistor) is connected in series to the low pressure arc tube (13) so as to control the current passing through the low pressure arc tube (13) to about 1 Amp. When the arc current having 5 to 6 Amp. is passed through the high pressure arc tube in the starting period, the voltage between the electrodes (10), (11) of the high pressure arc tube (8) is decreased to 20 to 30 vol.t, and the voltage between the electrodes (15),(16) of the low pressure arc tube (13) is decreased whereby the discharge of the low pressure arc tube (13) is stopped and only discharge of the high pressure arc tube (8) continues.
~8,921 In the stable state of the high pressure arc tube (8), a current havi~g ~ o ~ . is passed throu$h the circuit of the base (2)- stem lead ~l~)-electrode ~ -e~ectrode ~ support frame ~3)-stem lead (7)-base (2) to -the ballast, however any current is not passed through the circuit of the low pressure arc tube (13) and the impedance element 117) and the high pressure arc tube (8) maintains the stable state and the low pressure arc tube (13) is kept in the non~discharge state.
When the high pressure arc tube (8) is extinguished from the stable state by a temporary voltage d:rop of the power voltage, even though the power voltage is returned to the normal level, the pressure in the high pressure arc tube (8) is high as several atm. whereby the discharge of the high pressure arc tube (8) is not capable of the start.
Thus, when the power voltage is applied to the high pressure arc tube (8) in the state of incapable of the start, the low pressure arc tube (13) is capable of the start. Therefore, the low pressure arc tube (13) is immediately started when the high pressure arc tube (8) is extinguished.
The lighting is continued by the low pressure arc tube (13). Therefore, the discharge lamp continues light emission corresponding to the light emission character:istics of the low pressure arc tube (13) without causing a complete inactuation of the discharge lamp. In this condition, a current of 1 Amp. controlled by the impedance elemen-t (17) is passed through the circuit of the base (2)-stem lead (12)-impedance element (17)-electrode (16)-electrode (15)-support frame (3)-stem lead (7)-base (2) to the ballast (18), whereas any current is not passed through the high pressure arc tube (8).
When the temperature of the high pressure arc tube (8) is decreased under the condition of the actuation of -the low pressure arc tube (13), and the mercury vapor pressure in the arc tube is decreased to be capable of -the start of the discharge, the discharge of the high pressure arc tube (8) is started again and the stable state is given after 5 minutes and the light emission having desired elec-trical and optical %~
6 ~i8,921 characteristics is continued. In this e~m~lle, ~he time required for the resta~ ~i the discha~e of the high pressure arc tube (8) is about 10 minutes. When tbe disc~arge of t~ne high pressure arc tube (8) is started again, the discharge of the low pressure arc tube (13) is stopp-ed because of the sar~e i:unctiorl at the start of the discharge lamp.
Therefore, the low pressure arc tube (13) is not actuated during the actuation of the high pressure arc tube (8).
In said embodiment, the impedance element (17) is connected in series to the low pressure arc tube (13). When the glow discharge is continued in the state applying the power voltage to the low pressure arc tube (13), it is possible to eliminate the impedance element (17) only by the parallel connection of the low pressure arc tube (13) and the high pressure arc tube (8).
In said emebodiment, 400 W metal halide arc tube is used as the high pressure arc tube (8). Thus, it is not limited to use a 400 W
arc tube and it is possible to use arc tubes for high pressure mercury vapor discharge lamps and high pressure sodium vapor discharge lamps, etc. The arc -tube containing the mixed gas of neon and argon is used as the low pressure arc tube. Thus, it is possible to use an arc tube for low pressure mercury vapor discharge lamps, a fluorescent lamp or a rare gas discharge lamp. The pressure of the sealed gas in the low pressure arc tube (13) is preferably lower than 100 torr so as to start the discharge by the normal voltage. Thus, these lamps can be used.
In said embodiment, the resistor is used as the impedance element (17) connected in series to the low pressure arc -tube (13).
Thus, it is possible to use a capacitor, a choke coil, a filament coil or a combination of two or more of the capacitor, the choke coil, and the filament coil or the resistor as the impedance element.
The impedance of the impedance element (17) can be select-ed as desired depending upon the characteristic of the low pressure 7 ~8~921 arc tube (13).
When a filament coil is used as the impedance element (17), cer~ain light emission from the Eilament coil is given to make bright dur:ing ~ ac~llati~ of the low pressure arc tube ~13) beEore the restart of the high pressure arc tube (8~.
~ igures 3 and 4 show the other embodiment of the present invention wherein the reference numeral (20) designates a lighting equip-ment comprising a light transmiscible outer bulb (1), the high frequen-cy ballast (18) and a base (2). In the outer bulb (1), a high pressure arc tube (8), a tungsten filament (17) and a low pressure arc tube (13) are placed. The high pressure arc tube (8) has electrodes (10),(11) at each end, and one electrode (10) is connected to a support lead (3) and the other electrode (11) is connected to a lead (12) of the ballast (18). The support lead (3) is connected to the other lead (7) oE the ballast (18). The low pressure arc tube (13) has elec-trodes (15), (16) at each end, and one electrode 15 .is connected through the tungs-ten filament (17) to the support lead (3) and the electrode (16) is connected to the lead (12). Therefore, the low pressure arc tube (13) connec-ted in series to the filament (17) is electrically connected in parallel to the high pressure arc tube (8). The lead oE the ballast (18) at the power source side is connected to the base (2).
The high pressure arc tube (8) can be a 30 ~ metal halide arc -tube in which mercury, argon and scandium halide and sodiwD halide are filled in the sealed condition. The low pressure arc tube (13) can be a rare gas arc tube having an inner diameter of 5 mm and a distance between the electrodes (15),(16) of 10 mm and contains a mi~ed gas consisting of 99% of neon and 1% of argon under the pressure of 20 torr. The impedance element can be a tungsten filament (17) hav-ing 400 n for controlling the current in the low pressure arc tube (13) to 0.~ Amp. A inert gas is filled in the outer tube (1) so as -to prevent ~7~2~
~ 48,921 the ~Japorizati~n of tungsten from the filament and to prevent the oxida-tion of Lhe el~e~s plac~ iD ~he o~ter hulb.
~he lighting ~e~iipment having said structure is connected to the power source (19) as shown in Figure 4 whereby the high frequency voltage generated by the high frequency ballast (1~) is applied to the arc tube and the discharge of the high pressure arc tube (8) is started to pass the current controlled by the ballast ~18) through the high pressure arc tube (8).
The high pressure arc tube (8) reaches to the stable state about 3 minutes after the start of the discharge. When the discharge of the high pressure arc tube (8) is started, sometimes, the discharge of the low pressure arc tube (13) is simultaneously started for a moment.
A filament having relatively high resistance of 400 Q is conne-cted as the i.mpedance element (17) (resistor) to the low pressure arc tube (13). 'rherefore, the current passing through the low pressure arc tube is limited to 0.2 Amp. When the arc discharge current of 0.6 to 0.65 ~np. is passed through the high pressure arc tube at the start, the vol.tage applied between the electrodes (10),(11) of the high pressure arc tube (8) is decreased to about 20 Volt, and -the voltage applied bet-ween the electrodes of the low pressure arc tube (13) is lowered to stop the discharge in the low pressure arc tube (13) and only the high pre-ssure arc tube (8) continues the discharge.
In the stable sta-te of the high pressure arc tube (8), the current is passed through the circuit of the base (2)-ballast (18)-lead (7)-support lead (3)-electrode (10)-electrode (11)-lead (12)-ballast (18)-base (2) whereas any current is not passed through the low pressure arc tube (13) and an impedance element (17) whereby the high pressure arc tube (8) maintains the stable state whereas the low pressure arc tube (13) continues the non-discharge state.
9 ~18,92:1 ~he~ the high pressure arc tube (8) is extinguished from the sta'ble s~ate ~S~ ca te~pc,r~ry voltage drop of the po~er voltage, even though ~he power ~ol~ge is -leturned to the normal level, the pressure in the high pressure arc ~ube ~) is high as several atm. whereby the discharge o~ the high pressure arc tube (8) i.s not capable oE -the start.
Thus, when the power voltage is applied to the high pressure arc tube (8) in the state of incapable of the start, the low pressure arc tube (13) is capable of -the start. Therefore, the 1.ow pressure arc tube 113) is immediately star-ted when the high pressure arc tube (8) is extinguished.
The lighti.ng is continued by the low pressure arc tube (13) and the tungsten ~ilament (17). Therefore, the discharge lamp continues light emission corresponding to the light emission characteristics of the low pressure arc tube (13) and the tungsten filament (l73 without caus-ing a comple~e inactuation of the discharge lamp.
During the state, the high frequency current. of 0.2 Amp.
which is controlled by the filament (17) as the impedance element is passed through the circuit of the base (2)-ballast (18)-lead (7)-support lead (3)-filament (17) as the impedance e:lement-electrode (15)-electrode (16)-lead (12)-ballast (18)-base (2) whereas any current is passed through the high pressure arc tube (8).
When the temperature of the high pressure arc tube (8) is decreased under the condition of the operation of the low pressure arc tube (13) and the mercury vapor pressure in the arc tube is decreased to be capable of the start of the discharge, the discharge of the high pressure arc -tube (8) is started again and the stable state is given after 3 minutes, and the light emission having desired electrical and optical characteristics is continued. In this example, the time required for the restart of the discharge of the high pressure arc tube (8) is about 8 minutes. When the discharge of the high pressure arc tube (8) is started again, the discharge of the low pressure arc tube (13) is stopp-ed because of the same function at the start of the discharge lamp.
lO 4~,921 Therefore, the low pressure arc tube (13) is not actuated during the act~ation of the high pressure arc tube ~8).
The charac-teri~-ti~ oi the ~ighting equipment having the arc tube ~:f-the 30 ~ ~t~ a.ide ~apor discharge lamp and the characteris tics of lO0 W incandescent lamp are shown in Table 1.
As it is clear from the data of Table l, the lighting equipment o-l this example of the present invention has three -times of the effic~acy of the incandescent lamp and five times of the life of the incandescent lamp.
The luminous efficacy in Table I means efficacy of only the lamp as to-tal luminous flux/lamp power and the overall efficacy means total efficacy of the lamp and the ballast as total luminous flux/inpu-t power.
The 30 W metal halide vapor discharge lamp of -this embodi ment is operated by the high frequency current having 20 KH~ and accordingly, the loss caused by the ballast is smaller than that of the conventional discharge lamp and the inpu-t power is 34 W.
~ 8,921 Table 1 ._ _ _ Type ~ 100 W Light:ing equipment incandescent lalr~p having 30 W metal halide arc tube _.___ __.___ _ __ , _ Power of lamp 100 30 (Watt) ~oltage of lamp _ 60 (Volt) Current of lamp _ 0.56 (Amp.) Total luminous flux 1520 1500 Luminous efficacy 15.2 50 _ _ _ ___ ( lm ) __ __ _ I,i-fe (hr.) 1000 5000 In the embodiment shown in Figures 3 and 4, the tungsten filament as the impedance element (17) is connected to the low pressure arc tube (13). When the glow discharge is continued in the state apply-ing the power voltage to the low pressure arc tube (13), it is possible -to elimina-te the impedance element (17) only the parallel connection of the low pressure arc tube (13) and the high pressure arc tube (8).
In said embodiment, 30 W metal halide arc tube is used as the high pressure arc tube (8). Thus, it is not limited to use a 30 W
arc tube and it is possible to use arc tubes -for high pressure mercury vapor discharge lamps and high pressure sodium vapor discharge lamps, etc. The arc tube containing the mixed gas of neon and argon is used '7~
~ 48,921 as the low pressure arc tube. Thus, it i~ possi~le to use an arc tube Eor low pressure mercury vapor discharge lamps, a fluorescent lamp or a rare gas discharge lamp.
The pressure of the sealed gas in the low pressure arc tube (13)-is preferably lower than 100 torr so as to start the discharge by the norma]. voltage. Thus, these lamps can be used.
ln said embodiment, the resistor is used as the impedance element (17) connected in series to the low pressure arc tube (13).
Thus, it is possi.ble to use a capacitor, a choke coil, a filament coil, or a combination of two or more of the capacitor, the choke coil, and the filament coil or the resistor as the impedance element.
The impedance of the impedance element (17) can be select-ed as desired depending upon the characteristic of the low pressure arc tube (13).
~hen a filament coil is used as the impedance element (17), certain light emission from the filament coil is givell to make hright during the actua-tion of the low pressure arc tube (13) before the res-tart of the high pressure arc tube (8).
In said embodiment shown in Figures 3 and ~1, the frequency of the voltage and the current for the operating the arc tube (8) or (13) by generating from the high frequency ballast (18) is 20 KHz.
Thus, it is preferable to use the frequency ranging from 1 K}lz to 100 KHz. When the frequency is less than 1 KHz, the compact and light weight of the ballast are not satisfactory. When the frequency is greater than 100 KHz, the extinction phenomenon caused by unstable discharge in the xepeated starting of the high pressure arc tube (13) is took p].ace, and this is serious disadvantage in the practical use.
In accordance with the present invention, the high pressure arc tube for high pressure discharge is electrically connected in parall-el to the low pressure arc tube for low pressure discharge and botharc tubes are placed in the outer bulb whereby the discharge lamp is 13 48,92l usually opera~e~l by the high pressur~ ar~ -tube having high efficacy and when the high ~-~e~ re arc tu~e is e~i.nguished by c~rt~in factor, the low pressure arc tube i~ ~ctuated duri.ng the period ~rom the extinction to the restart of the high pressure arc tube to prevent the complete inactuation of the discharge lamp ancl to prevent complete darkness of the lighting part. The discharge lamp having remarkable advantages can be obtained.
~ en the high pressure arc tube for high pressure discharge is electrical.ly connected in parallel -to the low pressure arc tube for low pressure ~ischarge and both arc tubes are placed in the outer bulb and are operated by the high frequency ballast having 1 ~Iz to 100 KHz, the discharge lamp is usually operated by the high pressure arc tube having high efficacy and when the high pressure arc tube is extinguished b~) certain factor, the low pressure arc tube is actuated during the period from the extinction to the restart of the high pressure arc tube to prevent the complete inac-tuation of the discharge lamp and to prevent complete darkness of the lighting part. Moreover, the ballast can be compact -to be capable of a combination arc tubes and the ~allast as assembled :in one discharge lamp which can be used to replace for the incandescent lamp in the lighti.ng equipment.
The lighting equipment having remarkab].e advantages can be obtained.
Claims (5)
1. A discharge lamp which comprises a high pressure arc tube for high pressure discharge and a low pressure arc tube for low pressure discharge which is electrically connected in series to an impedance element and connected in parallel to said high pressure arc tube, and an outer bulb which both arc tubes are placed.
2. A discharge lamp according to claim 1 wherein said impedance element is a resistor.
3. A discharge lamp according to claim 1 wherein said impedance element is a filament coil.
4. A discharge lamp according to claim 1, 2 or 3 wherein said high pressure arc tube is an arc tube for a high pressure mercury vapor discharge lamp, a metal halide vapor discharge lamp or a high pressure sodium vapor discharge lamp.
5. A discharge lamp according to claim 1, 2 or 3 wherein said low pressure arc tube is an arc tube for a low pressure mercury lamp, a fluorescent lamp or a rare gas discharge lamp.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000357788A CA1187927A (en) | 1980-08-07 | 1980-08-07 | Discharge lamp and lighting equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000357788A CA1187927A (en) | 1980-08-07 | 1980-08-07 | Discharge lamp and lighting equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1187927A true CA1187927A (en) | 1985-05-28 |
Family
ID=4117589
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000357788A Expired CA1187927A (en) | 1980-08-07 | 1980-08-07 | Discharge lamp and lighting equipment |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1187927A (en) |
-
1980
- 1980-08-07 CA CA000357788A patent/CA1187927A/en not_active Expired
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