JP2978268B2 - Bias system for reducing ion loss in a lamp and method for preventing ion loss - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

FIELD OF THE INVENTION This invention relates to luminaires and ballast techniques for minimizing the loss of plasma material and ions from a live plasma confinement arc tube in a high intensity light emitting lamp.

[0002]

BACKGROUND OF THE INVENTION Sodium ions in high pressure sodium (HPS) lamps and ions of other elements in other types of lamps are lost through the walls of the arc containment means that contain the ionized gas under energized operating conditions. That has been known for some time.

[0003]

The basic problems are described in various documents and in prior patents. In order to form and maintain an ionized plasma conductor that produces light output in the lamp, it is necessary to place a metal such as sodium in the lamp and evaporate it to a gaseous state. Each type of lamp has a fill or starting gas, a certain amount of metal, halide and amalgam, each with a specific partial pressure so that the light output has the desired color spectrum and lumen levels when receiving the appropriate energy. And a mixture of elements activated by As the plasma material escapes from the lamp as an ion loss, the characteristics of the lamp deteriorate, resulting in a color shift and a decrease in lumen output level, resulting in inoperability with the desired design and operating characteristics. In addition, the useful life of the lamp is significantly reduced since lamp performance is reduced and lamp operating pressure is increased, causing undesirable operating changes.

Various proposals have been made to reduce such losses, but no practical, effective and economical solution has been found. Sodium loss is one of the main causes of the decrease in high-brightness light emission performance with the operation time.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrical system for reducing the loss of gas ions from a lamp structure in a lighting fixture.

It is yet another object of the present invention to provide a simple and inexpensive circuit that can be used to operate effectively with various types of ballast resistors and lighting fixtures.

[0007] Briefly, the present invention provides an electrical system for preventing ion loss from a plasma conductor in a high intensity light emitting lamp. The lamp includes an arc tube chamber containing an ionizable fill gas and a plasma material, such as a metal halide, which, when evaporated, aids in forming a plasma conductor upon emission of light and having a first terminal and a second terminal. First circuit means including a stable resistance element provides an AC operating voltage to the chamber. A conductive surface substantially surrounds and obstructs the chamber. A second circuit means having a negative terminal and a positive terminal is connected to a voltage source for producing a DC potential. Third circuit means connects one of the DC output terminals to one or both terminals of the chamber. The other DC
The output terminal is connected to a conductive surface surrounding the arc tube and creates an electric field between the conductive surface and the chamber to confine ions of the polarity of the surface into the chamber.

Preferably, the conductive surface includes a reflector generally located near the lamp, and the luminaire housing has a transparent window surface near the lamp but opposite the reflector, and the glass or plastic A second conductive surface consisting of a transparent thin film deposited over the window creates a bias electric field surrounding the lamp. Other conductive portions of the luminaire housing can also be used as bias-forming conductive surfaces, but a reflector located near the lamp will provide the greatest effect. Some lighting fixtures have a first reflector located in front of the lamp and a second reflector located behind the lamp. Each of these reflectors can have a curved surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

FIG. 1 is a simplified diagram showing the connection of the main elements of the device according to the invention. In the following, the invention will be described for lighting fixtures containing high pressure sodium or metal halides. However, it must be emphasized that the invention can be used for various types of lighting fixtures, and that the invention can be applied to light-emitting lamps using gases other than sodium.

The lighting fixture of FIG. 1 has a housing 10,
The housing has a transparent body 12, which can be a retractable door with a reflector or a glass panel. The light source itself includes a plasma conductor 14 formed in a chamber, such as an arc tube 16,
This tube contains an ionizable gas and is surrounded by an outer jacket or sheath 17. However, this lamp may not have an outer jacket as in many double-headed lamps. The shape and size of these elements vary depending on the type and manufacturer of the lamp. The reflector 18 is shown as being opposite the light source from the door or reflector 12, and the reflector 18 directs light from a portion of the light source in a special light pattern and surrounds the light source. Can be curved.

The AC supply circuit 20 includes a terminal 22 connectable to a standard AC voltage source. The AC supply circuit 20 supplies an AC output to conductors 24 and 25 connected to terminals at both ends of the lamp 14. The DC circuit means 28
Power is supplied from the C supply circuit 20 and outputs a DC voltage to the positive and negative output terminals 30 and 31, respectively. Chamber 16
In the illustrated embodiment with the sodium vapor plasma conductor 14 therein, the positive terminal of the DC circuit means 28 is connected to the reflector 18 and the negative terminal 31 is connected to the arc tube 16 at one end of the plasma conductor.

In operation of the simple circuit shown in FIG.
The AC supply circuit 20 sends an AC current from both ends of the arc tube 16 to the plasma conductor via conductors 24 and 25 to maintain the plasma in a state that produces light passing through the door or the reflector 12. Light is also directed or focused by a reflector 18. At the same time, a DC voltage is applied to the reflector and the plasma conductor, making the reflector positive to the plasma. Since the plasma contains sodium ions having a positive charge and a potential more positive than the plasma conductor is disposed on the reflector 18, an electric field is generated between the reflector and the plasma ions, and this electric field causes the positively charged plasma particles to be reflected. These plasma particles are trapped in the chamber 16 with a tendency to repel.
This electric field reduces the transport of these positive ions through the walls of the arc tube 16 and extends the life of the arc tube and maintains the sodium design balance, thus increasing the color and power of the light. Improve over time.

The operation of the apparatus of FIG. 1 is improved by applying a conductive coating 34 to the surface of the door or reflector 12 and connecting the positive terminal 30 to the coating.
As a result, the plasma can be enclosed in a repelling electric field from all sides of the light source, confining the plasma ions within the plasma, and further improving the operation of the device and extending its lifetime.

Further, as shown in FIG.
Are connected 35 to the housing 10. The housing is partially or entirely made of metal, and if not made of metal, it is partially made conductive by a conductive thin film or filler. By connecting the positive terminal to this conductive portion, the entire housing 10 can create an electric field that confines ions within the chamber 16.

Of particular importance is the provision of one or more surfaces that substantially surround and house the lamp, creating an electrical potential on these surfaces that repels ions and confine them within the arc tube chamber. This is done without the need to add devices inside the lamp itself. Such an internal device is a costly and undesirable method. If extra devices were incorporated into the outer jacket of the lamp, these devices would naturally be thrown away with the lamp at the end of the lamp's life. Lamp life can be extended.

FIG. 2 shows the relative positions of the light source 38, the reflector 39, the reflector 40, and the housing 41.
In this case, the reflector 39 is made of metal or has a metal surface, and the reflector 40 also has a metal surface, and the reflector, the reflector and the conductive housing 41
Connected to the positive terminal of circuit means 28, its negative terminal is connected to the plasma conductor light source. Again, assuming that a sodium vapor lamp is used, a three-dimensional electric field 42 is formed between the plasma conductor and the surrounding shell-like body, which is very important for confining the plasma particles inside the chamber. It is valid. Since the shell-like body substantially surrounds the light source, its confinement effect is great. Structures such as that shown in FIG. 2 are commonly used for optical reasons, but have not been used for field effect reasons or for confining plasma ions in a plasma stream.

FIG. 3 shows an embodiment in which this principle is applied to one type of lighting fixture. In this embodiment, the elements of the luminaire are housed in a housing 44. The housing 44 is made of metal or is filled with metal particles,
Alternatively, a metallized surface is applied. The housing opening receives a glass or plastic reflector 46, which has a conductive coating 48 applied to its inner surface. The coating 48 is, for example, tin oxide or indium oxide, which leaves the reflector substantially transparent, but renders its inner surface conductive. Such layers can be deposited on glass by conventional vapor deposition techniques.

A plasma chamber 16 surrounded by an outer jacket 17 is arranged behind the reflector 46, and a reflector 18 is arranged behind the light source.

The AC supply circuit 20 comprises a conventional metal halide lamp ballast resistor tube 50, which is typically an autotransformer having taps or common points arranged to connect to an AC power source. Or a peak load automatic regulator. Instead of the usual single ballast capacitor connected in series between this ballast transformer and the plasma chamber, two pieces connected in series with two AC conductors reaching the light source from the ballast transformer Are used. Each capacitor 52, 53 is selected to have twice the value of a single series capacitor used in a conventional ballast transformer so that the operating wattage of the lamp is accurate. These capacitors provide light source isolation so as to apply a DC bias to the light source.

The voltage dividing means includes a potentiometer 54 connected across the output of the transformer, the potentiometer having a contact 55 connected to the DC circuit means 28. The contact 55 is connected via a series resistor 56 and a diode 58 to a parallel connection circuit of a capacitor 60 and a resistor 61. The other side of the parallel connection circuit is connected to a common line, which is connected to the conductive housing 44 by a screw terminal 62.

The positive output terminal of the DC circuit serving as the common line is connected to the reflector 18 and the conductive coating 4 on the reflector 46.
8 is connected. The negative side is connected to the movable contact 59 of the potentiometer 57. Both ends of the potentiometer are respectively connected to terminals of the plasma conductor chamber. The resulting electric field traps positive ions in the chamber 16 and prevents migration of ions through the walls of the chamber. Since the positive terminal is connected to the housing at the terminal 62, the housing itself made of a conductive material contributes to the formation of the confined electric field.

As mentioned above, this device shown in FIG.
It can be used without the coating 48 because of the electric field created by the adjacent reflector 18 and housing. To further completely enclose the chamber and improve the confinement field effect, a reflector 1 as shown in FIG.
8 can be configured as a shell-like structure.

If the diode 58 is reversed, D
Because the C electric field can be reversed, essentially equivalent circuits can be used to confine positive or negative ions, the choice of which depends on the type of lamp and the ions or compounds used therein. Be careful.

FIG. 4 shows a circuit using an electromagnetic regulator.
The structure including the housing, the reflector and the light source is the same as in FIG. 3, and the same numerals are used. AC supply circuit 64
Is an electromagnetic regulator having a core 66 with three windings, all windings being insulated from the core and from each other. The isolated primary winding 68 is connected to a normal AC power supply. The output winding 70 is connected at its end to the chamber 14 and is tapped to be connected to the starting circuit 72. The starting circuit 72 is any starting circuit known in the art, which generates a voltage pulse through the top of the winding 70, which is augmented by the effect of an automatic transformation in the winding 70, and
A relatively high voltage pulse is produced between 4 and 75 and this pulse is applied to the de-ionized lamp to produce ignition. A suitable starting circuit is shown in FIG. 2 and others of U.S. Pat. No. 4,763,044. Magnetic shunt 6 across windings 68 and 70
5, 67 are arranged.

The floating stable resistor capacitor winding 76 includes a shunt capacitor 78, which performs the stable resistor capacitor function. This ballast resistance 76 does not interfere with the insulation of the primary winding, and the original A
Does not interfere with C operation. The winding 76 is connected via a diode 80 to a capacitor 82, across which a DC bias voltage appears which is connected to the lighting system elements. Bleeder resistor 83 in parallel with capacitor 82
Is connected. In this embodiment used for a sodium vapor lamp, the negative terminal of this DC power supply is connected to common line 75 and plasma conductor chamber 16. The positive terminal is connected to the reflector 18, the conductor coating 48, and the conductor housing 44. The function is the same as in the other embodiments described above, where an electric field is created between the reflector, the reflector and the plasma conductor chamber to trap gases and ions in the chamber.

Such a biasing technique allows for lamp design changes, such as increased loading (watts per square centimeter) of the arc tube wall made of quartz and polycrystalline alumina, and lumens / watt (LP). .M) resulting in increased power and improved color and other properties, without increasing the rate of sodium loss from plasma and arc tubes.

FIG. 5 shows a further embodiment of the plasma coupling circuit according to the invention, which is particularly simple and therefore economical and efficient. Automatic transformer 92 is connected to an AC power supply as in the embodiment of FIG.
An AC current is supplied to the lamp 94 via the series capacitors 96 and 97. A lamp starting circuit 98 is connected between the lamps of the capacitors 96 and 97. A reflector 99 for reflecting light generated in the lamp 94 is provided.

The DC circuit 100 includes a series connection of a diode 102 and a resistor 104, and a radio frequency choke 106 for blocking high frequency, high voltage pulses from the lamp starting circuit. The diode is polarized such that the inductive ballast side of capacitor 97 is positive with respect to the lamp side of the capacitor, and capacitor 96 is polarized such that the inductive ballast side of this capacitor is positive with respect to the lamp side. Poled. Capacitor 96 is dielectrically insulated from the housing. Finally, conductor 108 connects the neutral or ground side of inductor 92 to reflector 99 and lamp housing 90.

When this circuit is used, the neutral side of the inductive stable resistance element is positive with respect to the lamp and the lamp-side circuit of the capacitors 96 and 97. Thus, the plasma conductor itself becomes negative with respect to the reflector and the housing, creating an ion transfer inhibiting electric field, which improves lamp operation and life. Insulating the capacitor 96 from the housing with a dielectric isolation element prevents the high frequency-high voltage lamp ignition pulse from the lamp starting circuit 98 from being capacitively shorted. The stable resistance secondary coil serves as an inductance that suppresses the starting pulse from the starting circuit.
A charging circuit including diode 102, resistor 104 and choke 106 charges stable resistor capacitor 96 to the polarity shown. As the lamp ignites and draws a high AC lamp current, a portion of the charge on capacitor 96 is directed to ballast resistor 97, causing its DC voltage to be equal or opposite, and the net DC voltage along the lamp current loop. Reaches zero. However, the lamp plasma circuit is negatively biased with respect to the neutral or metal parts.

The swing of the AC voltage before and after the operating ramp of the circuit can have a peak amplitude close to or almost equal to the DC bias voltage. Thus, the voltage time during a half cycle in which a reverse bias is present to release sodium ions from the wall of the arc tube is very small.

The DC voltage is automatically adjusted by the lamp voltage clamp mechanism of this circuit. Such a charging circuit 10
Although two zeros can be used, this is not necessary as the AC power operation will transfer the required charge from one capacitor to the other.

To limit the current in the charging circuit, a resistor 104, typically having a value of 10K ohms and 1 watt, is used. As mentioned earlier, the RF choke blocks the high voltage from the starting circuit so that the high frequency-high voltage can cause the lamp to rise and ignite, and the high voltage will damage other charging circuit elements Can be prevented. Of course, the diode allows half-wave DC charging.

If it is necessary to discharge the stable resistor capacitor and the starting capacitor when the stable resistor dies, a high-resistance bleeder resistor can be connected before and after these capacitors. If rapid discharge is required, connect a small relay consisting of a normally closed series of contacts connected to a small resistor before and after each capacitor, respectively, and connect the relay coil along a wire or a stable resistance secondary wire. Rapid discharge can be performed.

FIG. 6 shows a reflector structure suitable for use in the present invention. The lamp 110 is the primary reflector 1
11 and a secondary reflector 112. By using these two reflectors, the light from the lamp can be emitted in a specific pattern through the reflector or cover-113. These elements are mounted on the housing 114 as in the previous structure.

By connecting one side of the DC power supply to both reflectors and the other side to one or both terminals of the lamp, these reflectors substantially surround the lamp and provide for other parts of the housing. A very efficient surrounding electric field because it is closer to the lamp than to the lamp. Any of the above circuit structures can be applied to this reflector structure.

In the above, the invention has been described with reference to a single luminaire. However, it is quite possible to apply the invention to all lighting fixtures of the same type throughout the building.
This is, of course, economic. The implementation technique is illustrated in FIG. Building 120 includes a number of lighting fixtures, two of which are indicated at 122 and 123. Each lighting fixture is a stable resistance transformer 1
25 and a stable resistor capacitor 126, these elements can be arranged in the same way as in FIGS.
It is not necessary. Each luminaire has a lamp 127 such as a sodium vapor lamp and a reflector 128. Also, the starting circuit can be arranged in the ballast circuit or together with the ballast circuit.

[0038] For a normal AC power supply to the building,
The AC current primary winding 129 and the DC isolation transformer 130 are connected. Lighting devices 122 and 123 are connected in parallel between the non-ground side terminal and the ground side terminal of the transformer secondary winding. Thus, in the luminaire of the illustrated embodiment, the primary portion of each luminaire is connected to an AC power source.

A DC power supply unit 132 is connected between the AC ungrounded electric wire coming out of the secondary side of the transformer 130 and the building ground, that is, the green electric wire in the three-wire power distribution system. Connected to earth. As a result, a DC bias is generated between the ground wire and the ground, and the ground becomes positive with respect to the ground wire. To provide the desired bias to confine ions within the lamp in accordance with the present invention, the reflector and / or reflector of each luminaire (corresponding to a particular reflector or housing structure).
Alternatively, the housing may be connected to ground. Since the plasma conductor is connected to the grounded AC line, it is automatically biased negatively with respect to ground. Thus, the reflector and / or the housing is made positive with respect to the plasma, producing the desired confinement field. In this manner, all wires of the lighting fixture need to be connected to the isolation transformer 130, even if other AC supply wires are used for other purposes in the building. Such a wire dedicated to DC bias is preferable.

The present invention is not limited to the above description, but can be arbitrarily modified and implemented within the scope of the gist.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of a lighting fixture illustrating the principles of the present invention including a plasma conductor chamber.

FIG. 2 is a schematic diagram illustrating a bias electric field formed in an exemplary luminaire structure according to the present invention.

FIG. 3 is a schematic circuit diagram of a first embodiment of a luminaire including a system according to the invention.

FIG. 4 is a schematic circuit diagram of a second embodiment of a luminaire including a system according to the present invention.

FIG. 5 is a schematic circuit diagram of a third embodiment of a luminaire including a system according to the present invention.

FIG. 6 shows a first reflector and a second reflector of a lighting device according to the present invention.
FIG. 5 is a partial side sectional view of a reflector portion.

FIG. 7 is a wiring diagram using the present invention for a number of lighting fixtures in a building.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Housing 12 Reflector 14 Plasma conductor 16 Arc tube 18 Reflector 20 AC supply circuit 28 DC circuit means 50 Stable resistance circuit 64 AC power supply 66 Core 68 Winding 70 Winding 72 Starting circuit 76 Stable resistance winding 92 Automatic transformer 98 Lamp starting Circuit 122 Lighting equipment 123 Lighting equipment

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-10567 (JP, A) JP-A-55-165566 (JP, A) JP-A-56-24751 (JP, A) JP-A 63-167 105456 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) H05B 41/14-41/29

Claims (19)

(57) [Claims] 1. An electrical system for preventing ion loss from a plasma conductor in a high intensity light emitting lamp, comprising: an ionizable fill gas; and a plasma material such as a metal halide which, upon evaporation, helps to form the plasma conductor when evaporated. An arc tube chamber containing a first terminal and a second terminal, and a first circuit means including a stable resistive element connected to the first and second terminals for supplying an AC operating voltage to the chamber. A conductive surface substantially surrounding and obstructing the chamber, a second circuit means connected to a voltage source for generating a DC potential and having a negative terminal and a positive terminal, and one of the output terminals connected to a terminal of the chamber. And the other output terminal is connected to the conductive surface to generate an electric field between the surface and the chamber to cause ions of the polarity of the surface to pass through the chamber. Biasing system to reduce ion loss in the lamp, characterized in that it comprises a combination of a third circuit means for confining. 2. The apparatus of claim 1, wherein the conductive surface includes a conductive reflector disposed on one side of the chamber to direct light generated in the chamber in a desired direction.
A bias system according to claim 1. 3. The circuit of claim 1, wherein said first circuit means includes an AC conductor having a first conductor and a second conductor for supplying an AC operating voltage to both terminals of the chamber and acting as an inductive stable resistance element during operation.
Inductive circuit means connected to a power supply, first and second stable resistance capacitors connected in series to said first and second conductors, and voltage dividing means connected to said inductive circuit means, 3. The bias system of claim 2, further comprising a voltage dividing means connected to said second circuit means for generating a DC potential difference. 4. The method of claim 1, further comprising a second conductive surface disposed opposite the first conductive surface with respect to the chamber, wherein the third circuit is connected to the first conductive surface. The bias system of claim 1, wherein an output terminal of the bias system is connected to the second conductive surface. 5. A conductive material comprising at least one partially transparent housing and said first conductive surface being disposed on one side of said chamber for directing light generated in said chamber in a desired direction. A reflector comprising a reflector, wherein the second conductive surface comprises a conductive substantially transparent coating supported on a surface of an at least partially transparent housing from the reflector on an opposite side of the chamber. The bias system according to claim 1. 6. The at least partially transparent housing includes a conductive outer housing for a lamp element and a circuit, the outer housing includes a transparent portion, and the third circuit means connects the negative output terminal to the outside. The bias system according to claim 5, wherein the bias system is connected to a housing. 7. The biasing system according to claim 5, wherein said at least partially transparent housing supporting said conductive coating includes a light transmissive wall portion of said outer housing. 8. The bias system according to claim 1, wherein said conductive surface is curved to at least partially surround said chamber. 9. The first circuit means includes inductive circuit means connectable to act as an inductive stable resistive element during operation, the inductive circuit means comprising a first winding connectable to an AC power source. A magnetically permeable core having
A second winding for applying a C operating voltage, and a third winding, wherein a stable resistance capacitor is connected between both terminals of the third winding, and the third winding is used for generating the DC potential. Is connected to the second circuit means.
A bias system according to claim 1. 10. The bias system according to claim 9, wherein said conductive surface includes a conductive reflector disposed on one side of said chamber to direct light generated in said chamber. 11. A method according to claim 11, further comprising a second conductive surface disposed on an opposite side of the first conductive surface with respect to the chamber, wherein
The bias system of claim 10, wherein a circuit connects the second conductive surface to the other output terminal connected to the first conductive surface. 12. A conductive material comprising at least one partially transparent housing and said first conductive surface being disposed on one side of said chamber for directing light generated within the chamber in a desired direction. A reflector comprising a reflector, wherein the second conductive surface comprises a conductive substantially transparent coating supported on a surface of an at least partially transparent housing from the reflector on an opposite side of the chamber. The bias system according to claim 9. 13. The at least partially transparent housing includes a lamp element and a conductive outer housing for a circuit, the outer housing includes a transparent portion, and the third circuit means connects the negative output terminal to the outer terminal. The bias system according to claim 12, wherein the bias system is connected to a housing. 14. The bias system of claim 12, wherein said at least partially transparent housing supporting said conductive coating includes a light transmissive wall portion of said outer housing. 15. The bias system according to claim 1, wherein said voltage source includes said first circuit means. 16. The circuit of claim 1 wherein said first circuit means includes a first conductor and a second conductor for supplying an AC operating voltage to both terminals of the chamber and for acting as an inductive stable resistance element during operation.
C inductive circuit means connected to a C power supply; and first and second stable resistance capacitors connected in series to the first and second conductors, and wherein the second circuit means comprises the first stable resistance. A diode and a resistor connected in series between a chamber side of the capacitor and an inductive stable resistor side of the second stable resistor capacitor, and the third circuit means includes:
The bias system of claim 1, further comprising a conductor connected between an inductive ballast side of the second ballast capacitor and the conductive surface. 17. A luminaire housing for housing said lamp and said first, second and third circuit means and means for isolating at least said first ballast resistor from said luminaire housing. 17. The electrical system according to claim 16, comprising: 18. The bias system of claim 17, wherein said third circuit means connects said inductive side of said second capacitor to a conductive portion of said luminaire housing. 19. A chamber containing an ionizable fill gas serving to form a plasma conductor and having a first terminal and a second terminal, and connected to the first and second terminals to provide an AC operating voltage to the chamber. DC method having positive and negative outputs in a method for preventing ion loss from a plasma conductor in a high intensity light emitting lamp of the type including a first circuit means including a stabilized ballast element and a conductive surface near a chamber.
Generating a potential, connecting one DC output having a polarity opposite to that of the ions of the plasma conductor to one of the first and second terminals of the chamber, and connecting the other DC output to the conductive surface; Forming an electric field between the conductive surface and the chamber to confine ions having the polarity of the conductive surface in the chamber.