JPH05335000A - High pressure electric discharge lamp - Google Patents

Abstract

PURPOSE:To provide a high pressure electric discharge lamp in which two arc tubes enclosed in an outer tube are surely started with probability of 50% for each. CONSTITUTION:Two arc tubes 5a, 5b which are started in response to high- tension pulses whose polarities are inverted with respect to each other are electrically connected in parallel and enclosed in an outer tube 1 and are provided with proximity conductors 17a, 17b of different polarities. The two arc tubes are such that the difference between a discharge starting voltage for the high-tension pulse of the positive electrode side and that for the high-tension pulse of the negative electrode side is more than 10% of the smaller of the discharge starting voltages. A pulse generated at a starting pulse generator circuit portion by an AC power supply has either positive or negative polarity with probability of 50% for each and the probability of either of the two arc tubes being started is also 50% each.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high pressure discharge lamp in which two arc tubes are housed in an outer tube and are alternately lit.

[0002]

2. Description of the Related Art In a high-pressure metal vapor discharge lamp such as a high-pressure sodium lamp or a metal halide lamp, the internal pressure of the arc tube becomes 1 atmospheric pressure or more during lighting, so when the lamp is restarted after the lamp is turned off, the arc tube cools down to some extent. It is necessary to wait for the mercury and the enclosed luminescent metal to aggregate and the internal pressure to drop below a predetermined level. For example, in the case of a high-pressure sodium lamp with an external starter, it takes about 1 minute as the restart time, and in the case of a metal halide lamp, 10 minutes or more must be waited. I have to wait a few more minutes.

Therefore, for example, in the case of a momentary power failure, in the case of an incandescent lamp or a fluorescent lamp, the lamp is immediately restored and lit, but in the case of the above high-pressure metal vapor discharge lamp, it is necessary to wait for 10 minutes or more before the full power is exerted. This is inconvenient when used for road lighting, tunnel lighting, etc.

To improve this, USP 4,287,
No. 454 describes housing two arc tubes in an outer tube,
A high-pressure sodium lamp has been proposed in which these arc tubes are electrically connected in parallel and one of these arc tubes is alternately turned on.

In the case of such a lamp, one of the arc tubes is normally lit during normal operation, and when the power failure is resolved after the lamp is extinguished by a momentary power failure, the other arc tube having a low internal pressure is lit. In this case, the other arc tube is preheated when the one arc tube is turned on, and the internal pressure is slightly increased, so that the stable lighting state is reached in a few minutes. Therefore, the restart time is extremely short, which is convenient for the above-mentioned road lighting and tunnel lighting.

In addition, in such a lamp, even if one of the arc tubes is difficult to light, the other arc tube is turned on, so that the life of the lamp is greatly extended, and theoretically, a type in which one arc tube is accommodated is used. 2 times the life of the lamp.

[0007]

By the way, the above-mentioned lamp in which two arc tubes are connected in parallel to the outer tube and accommodated therein is the one that is easier to start when starting at normal room temperature. Light.

That is, the two arc tubes have a slight difference in the starting voltage due to manufacturing variations, and the arc tube with the lower starting voltage is more likely to start, so that the arc tubes are started. For this reason, in a normal start, the arc tube on the side that is easy to start is always biased.

That is, of the two arc tubes, one of the two arc tubes, which is easy to start, is intensively started every normal start, and the frequency of use of the arc tubes increases. In such a case, sodium disappears in the arc tube which is unevenly turned on, and the lamp voltage rises. Therefore, one of the arc tubes deteriorates and disappears.

When one of the above-mentioned arc tubes becomes unusable, the remaining arc tubes start and light up. However, when this state is reached, instantaneous relighting cannot be expected, and the intended function of this type of lamp. Loses.

The reason why one of the arc tubes that is biasedly started becomes unusable is that the increase in the lamp voltage is the main cause, and therefore the above-mentioned extinction occurs in the latter half of the life of this type of lamp. The arc tube lights up first,
When this arc tube goes out, it is switched to the remaining arc tube and turned on.However, while repeating such extinguishing, the arc tube that was previously lit leaked, so that a rare gas leaked into the outer tube. The starting pulse is absorbed by the rare gas, the remaining arc tube becomes unstartable, and even if it is started, the temperature of the arc tube does not rise due to the heat conduction of the leaked rare gas, and the lamp voltage does not rise, and There is a problem of reduced efficiency.

It is an object of the present invention to provide a high pressure discharge lamp in which two arc tubes are started at a rate of half, and uneven start can be prevented from being concentrated.

[0013]

In order to achieve the above object, a high pressure discharge lamp according to claim 1 has two light emitting elements which are started by applying high voltage pulses whose polarities are reversed to each other in an outer tube. The tubes are accommodated in a state in which these arc tubes are electrically connected in parallel, and each of these arc tubes is provided with a proximity conductor for assisting in starting, and the proximity conductors attached to each of these arc tubes have polarities different from each other. The discharge start voltage for the high voltage pulse on the positive electrode side of one arc tube is Va _s1 , the discharge start voltage for the negative electrode side is Va _s2, and the high voltage on the positive electrode side of the other arc tube is If the discharge start voltage for the pulse is Vb _s1 and the discharge start voltage for the negative electrode side is Vb _s2 , the difference between the absolute values of the two discharge start voltages of one arc tube (the difference between the absolute values of Va _s1 and Va _s2 ) These 2 While 10% or more with respect to the smaller value of the discharge start voltage of the discharge starting voltage (Izure or smaller value of Va _s1 and Va _s2) of, even in the other of the arc tube, two discharge starting voltage Difference in absolute value of (Vb _s1
And the absolute value difference between Vb _s2 and Vb _s2 ), the smaller one of these two discharge _firing voltages (Vb _s1 and Vb
_It is characterized in that it is configured to be 10% or more with respect to _s2 , whichever is smaller.

A high pressure discharge lamp according to a second aspect of the present invention is a high pressure discharge lamp, wherein a plurality of arc tubes whose lighting is controlled by a starting pulse and proximity conductors attached to the arc tubes and having different polarities are energized. And an AC power supply supplied to these arc tubes and a pulse that oscillates on both sides at predetermined intervals of this AC power supply are superimposed on a sine wave, and the higher peak value on both sides is V _H. , Where V _L is the lower one, V _H > V _L
It is composed of a starting circuit section for generating a starting pulse having a pulse width of x1.1 and a pulse width at 90% position of V _H of 1 μs or more.

In the high pressure discharge lamp according to the third aspect of the present invention, in order to perform the lighting control of the desired arc tube more surely, the starting circuit portion of the second aspect causes the switching circuit to be switched to the opposite pole side every half cycle of the AC power source. The oscillating pulse was superimposed on the sine wave.

Also, in the high pressure discharge lamp according to the fourth aspect, in order to perform the lighting control of the desired arc tube more surely, the starting circuit section according to the second aspect causes the bipolar electrode side for every plural cycles of the AC power source. The oscillating pulse was superimposed on the sine wave.

In the high pressure discharge lamp according to the fifth aspect of the present invention, in order to perform more reliable lighting control of a desired arc tube, a pulse oscillating on both sides is sine wave a plurality of times in a predetermined cycle of the AC power source. It was made to be superimposed on.

[0018]

In general, in a high-pressure discharge lamp in which a proximity conductor for starting assistance is attached to the arc tube, it is possible to apply a positive polarity pulse or a negative polarity pulse to the proximity conductor. Even start to start. Further, when a pulse is generated by a starting pulse generator that uses an AC power source as a power source, the probability that the generated pulse will be positive or negative is 50% each, so it corresponds to the polarity of this pulse. If each arc tube can be started, the two arc tubes housed in the outer tube will be started with a probability of 50%.

Therefore, in the high-pressure discharge lamp according to claim 1, the difference between the discharge start voltage for the high-voltage pulse on one pole side of each arc tube and the discharge start voltage for the high-voltage pulse on the other pole side is: Since the discharge start voltage of the smaller one of these two discharge start voltages is set to 10% or more, each arc tube has a starting polarity difference, and the discharge start voltage of 50% is surely obtained. It is possible to start with a probability.

In the high-pressure discharge lamp according to the second aspect of the present invention, a pulse oscillating on both sides of the alternating current is superposed on the sine wave at a predetermined cycle, and the higher peak value on the both sides is V.
_{When H} and the lower one are V _L , V _H > V _L × 1.1
In addition, since a starting pulse with a pulse width of 90% _VH at a pulse width of 1 μs or more is generated, each arc tube also has a starting polarity difference, and it is possible to reliably start with a probability of 50%. Becomes

In the high pressure discharge lamp according to claim 3,
A pulse that oscillates on both poles is superimposed on a sine wave every half cycle of the AC power supply, and the higher one of the peak values on both poles is V _H ,
When the lower one is V _L , V _H > V _L × 1.1 and V
_Since a starting pulse having a pulse width of 90% of _H at a pulse width of 1 μs or more is generated, each arc tube also has a starting polarity difference, and the starting can be reliably performed with a probability of 50%.

In the high pressure discharge lamp according to claim 4,
When a pulse that oscillates on both sides of the alternating current power supply is superimposed on a sine wave at each of a plurality of cycles of the AC power supply, and the peak value on the both sides is V _H and the lower one is V _L , V _H > V _Since a starting pulse having a pulse width of _L × 1.1 and a 90% _VH position of 1 μs or more is generated, each arc tube also has a starting polarity difference, and with a probability of 50%. It becomes possible to start.

In the high pressure discharge lamp according to claim 5,
When a pulse oscillating on both sides is superimposed on a sine wave a plurality of times in a predetermined cycle of the AC power supply, and the peak value on the both sides is V _H and the lower one is V _L , V _H > _VL x 1.1
In addition, since a starting pulse with a pulse width of 90% _VH at a pulse width of 1 μs or more is generated, each arc tube also has a starting polarity difference, and it is possible to reliably start with a probability of 50%. Becomes

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on the first embodiment shown in FIGS. FIG. 1 is a configuration diagram of a high-pressure sodium lamp, FIG. 2 is a circuit configuration diagram showing a lighting circuit together with the high-pressure sodium lamp, and FIG. 3 is a voltage waveform of the lighting circuit.

In FIG. 1, reference numeral 1 denotes an outer tube of a high-pressure sodium lamp, which is made of hard glass or the like and has a substantially straight tube shape. A base 2 is attached to one end of the outer tube 1. The base 2 is a screw-type base having a shell 3 and an eyelet terminal 4. The outer tube 1 accommodates two arc tubes 5a and 5b.

These arc tubes 5a and 5b are airtightly joined to an end portion of a bulb made of a ceramic tube such as polycrystalline alumina or single crystal alumina, and an end plate made of a ceramic disk as a closing wall. The electrodes 6 ... Are sealed together.

Each electrode 6 ... Is constructed by winding a coil portion 6a around an electrode shaft as is well known, and holds a predetermined emitter. Such an electrode 6 ... Is connected to a conductive structure 7. Has been done. Each of these conductive structures 7 is projected to the outside from the end plate at the end of the valve. The arc tubes 5a and 5b are filled with sodium, mercury, and xenon (Xe) gas.

The arc tubes 5a and 5b appear to be arranged in parallel with each other when viewed from the front in FIG. 1A, but the side surfaces shown in FIG. 1B. In the case of an arrow, they are arranged in an X-shape so as to intersect with each other, and such arrangement reduces the shadow of the arc tubes on the non-lighting side.

The conductive structures 7, 7 located above the arc tubes 5a, 5b, respectively, are provided with support wires 9a, 9b via valve holders 8a, 8b made of a heat-resistant metal such as niobium or tantalum. Mechanically linked to.
In this case, the conductive structure 7 of one arc tube 5a is electrically connected to the support wire 9a via the bulb holder 8a, while the conductive structure 7 of the other arc tube 5b is the bulb holder 8b. On the other hand, it is electrically insulated by an insulating tube 16a made of ceramics or the like. The conductive structures 7 and 7 located above the arc tubes 5a and 5b are electrically connected to each other by a connection wire 18a made of a heat resistant metal such as niobium or tantalum.

The conductive structures 7 and 7 located below the arc tubes 5a and 5b, respectively, are provided with the support wires 9a via valve holders 10a and 10b made of a heat resistant metal such as niobium or tantalum. , 9b mechanically connected. In this case, the conductive structure 7 of the one arc tube 5a is electrically insulated from the bulb holder 10a by the insulating tube 16b made of ceramics or the like, and the conductive structure 7 of the other arc tube 5b is the bulb holder. -1
It is electrically connected to 0b. In addition, the conductive structures 7 located below the arc tubes 5a and 5b,
7 are also electrically connected to each other by a connecting wire 18b made of a heat resistant metal such as niobium or tantalum.

Arc tubes 5a and 5b having such a connection structure
Are electrically connected in parallel to each other.
That is, the support wires 9a and 9b are made of conductive wires, and their upper ends are connected to each other in an insulating state by the insulating bridge 11. These upper ends are elastic plates 12a and 12b.
It is locked to the top portion of the outer tube 1 via.

The lower ends of the support wires 9a and 9b are welded to the sealing support wires 13a and 13b, and these sealing support wires 13a and 13b are sealed to the stem 14 of the outer tube 1. These sealing support wires 13a and 13b are external conductor wires 1.
It is connected to the shell 3 of the base 2 and the eyelet terminal 4 by 5a and 15b.

Proximity conductors 17a and 17b are provided on the outer sides of the respective arc tubes 3a and 3b so as to be assisted in starting. These proximity conductors 17a and 17b are formed by bending a heat-resistant metal wire such as niobium or tantalum into a substantially U shape, and both ends thereof are welded to the support wires 9a and 9b, respectively, and an intermediate portion emits light. It is attached so as to be close to or in contact with the outer surfaces of the tubes 3a and 3b. The electrode sides of the adjacent conductors 17a and 17b are arranged at least within 2 mm from the electrode tips. However, it may extend beyond the electrode tip to the coil portion 6a.

Therefore, these adjacent conductors 17a, 17
Since b is welded to the support wires 9a and 9b having different polarities, b is electrically connected so that the polarities are different from each other. In addition, 19 shows a getter. Further, the inside of the outer tube 1 is kept in a high vacuum of about 10 ⁻⁴ .

The lamp having such a structure is used by being connected to the lighting circuit shown in FIG. This lighting circuit includes a choke coil type ballast 21 connected to an AC power source 20, and a starting pulse generating circuit section 22 which is well known and therefore omits a detailed configuration. These choke coil type ballasts 2
1 and the starting pulse generating circuit unit 22 are configured as a dedicated device outside the lamp.

Such a lighting circuit changes the AC voltage V from the AC power source 20 to the AC voltage V as shown in FIG.
For example, 3000 generated by the start pulse generation circuit unit 22
A pulse P of about volt is applied to the lamp by superimposing it on each half cycle.

In such a configuration, when the power switch is turned on to start the lamp, the starting pulse generating circuit section 22 of the lighting circuit superimposes on the AC voltage V from the AC power source 20, as shown in FIG. Then, the pulse P generated by the starting pulse generating circuit section 22 is superimposed and applied to the lamp. In this case, high-voltage pulses are applied to the positive and negative sides of the AC voltage V, that is, the starting pulses alternate every half cycle.

In the lamp, when the proximity conductor to which the potential of the opposite polarity is applied faces the electrode on the side of the cathode potential, the arc tube is easy to start. When a negative pulse is applied to the lead wire 15a, the one arc tube 5a, in which the adjacent conductor 17a and the electrode having the cathode potential are opposed to each other, is started. Further, when a positive pulse is applied to the external conductor 15a, the other arc tube 5b, in which the proximity conductor 17b and the electrode having the cathode potential are opposed to each other, is started. Since the polarity of such a starting pulse is inverted with a probability of 50%, the probability that each of the arc tubes 5a and 5b is started is 50%.

This ratio is equalized as the number of times of lighting is increased, so that one arc tube is prevented from being biasedly and intensively started. For this reason, it is possible to prevent the frequency of use of one of the arc tubes from increasing, and to eliminate problems such as the concentration of sodium in one arc tube being concentrated and the lamp voltage rising, and the deterioration of the lamp prematurely. As a result, the life of the lamp is doubled as compared with a lamp containing one arc tube.

Moreover, when one of the arc tubes is turned on, it is turned off by a momentary power failure, and when this power failure is resolved,
The arc tube with the lower pressure, which was not lit up to that point, is lit. In this case, the other arc tube is preheated when the one arc tube is turned on, and the internal pressure is slightly increased, so that a stable lighting state is reached in a short time. Therefore, the restart time is extremely short, and the brightness can be restored in a short time when used for road lighting or lighting in tunnels, so that safety can be improved.

By the way, when a negative pulse is applied to one of the light emitting tubes, for example, the adjacent conductor 17a adjacent to 5a, a positive pulse is applied to the other arc tube, for example, the adjacent conductor 17a adjacent to 5b. The same phenomenon as when the pulse of is applied. In general, when a proximity conductor is attached to the arc tube, the startability is improved by applying a negative pulse to the proximity conductor facing the electrode that operates as a cathode, as described above. Such arc tubes sometimes start even when a positive pulse is applied to the adjacent conductor.

Therefore, even when a positive pulse is applied to the adjacent conductor in the vicinity of one of the arc tubes,
In some cases, the arc tube on the side of the adjacent conductor may start. This is because the starting characteristics of the arc tubes 5a and 5b vary due to manufacturing variations.

That is, for example, the discharge start voltage is Va _s1 when the positive pulse is applied to the adjacent conductor 17a close to one of the arc tubes 5a to start the arc tube 5a.
The discharge start voltage when a negative pulse is applied to the adjacent conductor 17a to start the arc tube 5a is Va _s2 (usually Va _s1 > Va _{s2 in} absolute value), and to the other arc tube 5 b. The discharge start voltage when a positive pulse is applied to the adjacent proximity conductor 17b to start the arc tube 5b is Vb _s1 , and a negative pulse is applied to the proximity conductor 17b to move the arc tube 5b. The discharge start voltage at the time of starting is set to Vb _s2 (normally, the absolute value is Vb _s1 > Vb _s2 ).

Due to variations in the starting characteristics of the arc tube, the discharge start voltage V when the positive pulse is applied to the one adjacent conductor 17a to start the arc tube 5a is started.
a _s1 and the discharge start voltage V when a negative pulse is applied to the other adjacent conductor 17b to start the arc tube 5b.
In the relationship with b _s2 , when the absolute value is Va _s1 <Vb _s2 , the startability of one of the light emitting tubes 5 a is good even though the negative pulse is applied to the other light emitting tube 5 b. Therefore, the arc tube 5a here is started.

On the contrary, the discharge start voltage Va _s2 when a negative pulse is applied to the one adjacent conductor 17a to start the arc tube 5a, and a positive pulse is applied to the other adjacent conductor 17b. in relation to the discharge start voltage Vb _s1 when to start the arc tube 5b Te, the absolute value Vb _s1
<When becomes Va _s2, also regardless, it will start the other arc tube 5b to the application of the negative pulse to one of the arc tube 5a side.

Such a problem is caused by variations in the starting characteristics of the arc tube. In order to surely realize the above-described operation of the present invention, such malfunction is prevented. There is a need.

That is, the discharge start voltage Va _s2 when a negative pulse is applied to one of the adjacent conductors 17a to start the arc tube 5a, and a positive pulse is applied to the other adjacent conductor 17b. If Va _s2 <Vb _{s1 in} relation to the discharge start voltage Vb _s1 when starting the arc tube 5 b, one of the arc tubes 5 a is reliably started.

Similarly, the discharge start voltage Vb _s2 when a negative pulse is applied to the other adjacent conductor 17b to start the arc tube 5b, and the one adjacent conductor 17 at this time
In relation to the discharge start voltage Va _s1 when the positive pulse is applied to a to start the arc tube 5a, Vb
_{If s2} <Va _s1 , the other arc tube 5b is surely started.

Therefore, as a result of various experiments and researches conducted by the present inventors, the absolute value Vb _s1 -Va _s2 or Va _s1 -V is obtained.
The discharge start voltage Va _s2 or Vb with the lower difference S of b _s2
If _s2 relative to 10% or more, since they produce difference between Vb _s1 and Va _s2 or Va _s1 and Vb _s2,, that towards the arc tube negative pulse is applied to start reliably I stopped.

That is, the present inventors have rated input of 250 W.
Using a class high-pressure sodium lamp, an arc tube was manufactured in which the length X of the adjacent conductor (the distance between the electrodes was L) and the filling pressure (Torr) of the xenon gas were changed, and two arc tubes were combined. In this case, the difference in discharge starting voltage and the occurrence rate of bias in starting were measured.

The difference in the discharge start voltage is the discharge start voltages Va _s1 and Vb _s1 when a positive pulse is applied to each of the two adjacent conductors to start the arc tube, and the negative polarity of these adjacent conductors. The discharge start voltages Va _s2 and Vb _s2 when the arc tube is started by applying the pulse _{No. 2} are measured, and a combination having a smaller discharge start voltage difference between these arc tubes is selected and selected. Between the arc tubes of the above combination, the discharge start voltage is V _s1 when the positive pulse is applied to the adjacent conductor to start the arc tube, and the negative pulse is applied to the other adjacent conductor. The discharge starting voltage when the arc tube was started was set to V _s2 . Then, the difference between the absolute values of the discharge start voltage due to these positive and negative polarity pulses is S (S = lV _s1 −V _s2 l), and this difference S is the lower value of the discharge start voltage (usually of the negative polarity). Ratio when divided by the discharge start voltage V _s2 ) when a pulse is applied
Is referred to as a polarity voltage difference Φ. The above measurement results are shown in Tables 1 and 2 below. Each measured value is an average value when 10 high pressure sodium lamps were tested.

[0052]

[Table 1]

[0053]

[Table 2]

From the above Tables 1 and 2, if the polarity voltage difference Φ is 10% or more, the deviation occurrence rate of starting after lighting for 12000 hours is 5% or less, and even after lighting for 24000 hours. In addition, it is possible to suppress the occurrence rate of bias in starting to 10% or less. This means that the discharge start voltage of the arc tube is deteriorated by about 10% during the life of the lamp. Therefore, if the polarity voltage difference Φ is set to 10% or more, as described above, Can be started with a probability of 50%, and the deviation can be reduced even during the life of 24000 hours.

If the length X of the adjacent conductor extending from the opposite electrode tip position toward the other electrode is L / 3 or L / 2 with respect to the interelectrode distance L, the filling pressure of xenon is set. Even when the pressure was 150 Torr or less, the discharge starting voltage could be 3000 V or less, and the discharge in the outer tube and the undesired discharge in the die could be avoided.

From the above, the outer tube 1 is accommodated in the 2
Each of the arc tubes 5a and 5b has a discharge starting voltage V when a positive pulse is applied to the adjacent conductor to start the arc tube.
_{The difference} between _s1 and the discharge start voltage V _s2 when a negative pulse is applied to the adjacent conductor to start the arc tube is the difference S (S = lV _s1 −V _s2) between the absolute values of these discharge start voltages. l)
Is 10% with respect to the lower value of the discharge start voltage (V _s2 ).
By using a combination of arc tubes having the above polarity voltage difference Φ, the starting probability can be kept at 50% by the end of life.

In the above embodiment, the case where the starting pulse generating circuit unit 22 is installed as a dedicated device outside the lamp has been described, but the present invention is not limited to this, and the second embodiment shown in FIG. 4 is used. Such a configuration may be adopted.

That is, FIG. 4 shows the case where the starting pulse generating circuit section is housed inside the outer tube 1,
This starting pulse generating circuit section is provided with a bimetal switch 40.
It is configured by connecting a heat responsive switch including the above and a heater 41 for heating the switch in series, and this series circuit is connected in parallel with each of the arc tubes 5a and 5b.

In the case of such a structure, since the bimetal switch 40 is closed and the heater 41 is energized when the lamp is started, the heater 41 generates heat, and the heat causes the bimetal switch 40 to open. A kick voltage is generated at the time of this opening, and a pulse due to this kick voltage is superimposed on the power supply voltage of the ballast 21.

Then, such a bimetal switch 4
Since the pulse generation circuit section including 0 and the heater 41 also generates positive and negative high-voltage pulses for each half cycle of the alternating current, the probability of applying a negative pulse to the adjacent conductors 17a and 17b of the arc tubes 5a and 5b. Is 50% each, and therefore the probability that each of the arc tubes 5a and 5b will be started at the time of starting is 50%.

The high-pressure sodium lamp in which such a starting pulse generating circuit unit is housed in the outer tube 1 can be used as a choke coil stabilizer, and the lighting circuit has a simple and inexpensive structure and can emit high-pressure mercury. Since it can also be used in a lighting circuit of an electric lamp, there is an advantage that compatibility occurs.

Further, since the arc tubes 5a and 5b shown in FIG. 1 are arranged so as to intersect with each other in an X shape when viewed from the side, the arc tubes 5a and 5b shown in FIG. Valve holder-8a, 8b, 10a, 10b
Although it is supported by the support wires 9a and 9b through the above, the mounting structure of the respective arc tubes 5a and 5b becomes complicated and the mutual arc tubes 5a and 5b cross each other in an X shape. It is difficult to maintain the placement posture with high accuracy. A structure which improves this is shown in FIGS. 5 and 6 as a third embodiment.
Is shown in.

That is, in the third embodiment, heat-resistant valve support plates 50a and 50b such as ceramics are provided above and below each arc tube 5a and 5b. The support wires 9a and 9b penetrate the ports 50a and 50b and are mechanically fixed. The conductive structures 7 extending in the vertical direction of the arc tubes 5a and 5b respectively correspond to the bulb supporting plates 50a and 5b.
It is positioned by being inserted through the support holes 51 ... (Or slit) formed in 0b, and the tolerance angle is always made constant.

Such valve supporting plates 50a, 5
If 0b is used, it is easy to keep the arc tubes 5a, 5b in an arrangement posture that intersects in an X shape, and the arc tube 5
Undesired light in the top direction of the outer tube 1 caused by tilting a and 5b can be eliminated. 7 and 8
Shows a fourth embodiment of the present invention. In this embodiment, reliable lighting control of the arc tubes 5a and 5b is obtained by pulses.

More specifically, by using the starting pulse generating circuit section 22 of the lighting circuit shown in FIG. 2, a pulse oscillating on both sides for each half cycle of the AC voltage V as shown in FIGS. 7 and 8. P is superimposed on the sine wave, and at this time, the higher value V _H of the peak values on both sides is increased by 10% or more of the lower value V _L (V _H > V _L * 1.1), In addition, a pulse having a pulse width of 90% position of V _H of 1 μs or more (to make the start effective and reliable) is output as the start pulse. In addition, this pulse includes two arc tubes 5a,
Enough pulses to start 5b. Even if the arc tubes 5a and 5b are started using this pulse, each arc tube 5
It is possible to reliably start a and 5b with a probability of 50%.

That is, when the start-up of the two arc tubes 5a and 5b was tested by the "life test in which ON and OFF are repeated for 5.5 hours to 0.5 hours", the results are shown in Tables 3 and 4. It was a good result.

[0067]

[Table 3]

[0068]

[Table 4]

Looking at the results of the test, when Φ> 10% or more, the two arc tubes 5a and 5b are first in the pulse generation phase, that is, in the phase of "0-180 °" as shown in FIG. Pulse appears or "180 ° -360 °"
Each of them was lit almost correspondingly to the first pulse appearing in the phase, and in either case, it was not biased to one arc tube and lit. Even in the long-term life test, no deviation in the phase of the pulse was observed, and "0-180 °", "1"
"80 ° -360 °". This means that the lighting of the arc tubes 5a and 5b is almost 5
It can be seen that it is divided by 0%. As a result, the lamp life could be extended from 12000 hours to 24000 hours. On the other hand, Φ ≦ 10% or less (V _H ≦
At 1.1 * V _L ), there was uncertainty in all cases. FIG. 8 shows an essential part of the fifth embodiment of the present invention.

This embodiment is a modification of the fourth embodiment, and V
_H > V _L * 1.1 and pulse width at 90% of V _H ≧
A pulse satisfying the condition of 1 μs or more is continuously generated at a plurality of cycles.

As a result of the test, in this way, even in the case of "X = 2 / 3L" in Table 3, the occurrence rate of starting bias can be suppressed to within 5%, and the arc tubes 5a and 5b can be more reliable. The lighting could be controlled. FIG. 9 shows a sixth embodiment of the present invention.
The essential part of the Example of is shown.

This embodiment is a modification of the fourth embodiment, and V
_H > V _L * 1.1 and pulse width at 90% of V _H ≧
A pulse satisfying the condition of 1 μs or more is generated a plurality of times for each sine wave in one and a half cycles. As a result of the test, even in this case, even in the case of “X = 2 / 3L” in Table 3, the starting deviation occurrence rate could be suppressed to within 5% as in the case of the fifth embodiment.

Although the starting pulse generating circuit section 22 of the lighting circuit shown in FIG. 2 is used for the starting pulse control, the bimetal switch 40 and the heater 4 shown in FIG. 4 are used.
1. Even if the starting pulse generating circuit unit 22 including the ballast 21 is used, the starting pulse generating circuit unit 22 including the series circuit of the non-linear capacitor 60 and the amphoteric thyristor 61 as shown in FIG. May be.

Further, as in the eighth embodiment shown in FIG. 11, the proximity conductors 17a and 17b are provided over the entire region in the longitudinal direction at the positions opposite to the arrangement direction of the arc tubes 5a and 5b, respectively, to emit light. Both the tube 5a and the arc tube 5b are slightly separated from the surface with respect to the near conductor on the side closer to the arc tube, and are sufficiently separated from the near conductor 17b on the far side,
As shown in Tables 5 and 6, it was confirmed that when Φ> 10%, the same effect as that of the fifth example was obtained.

[0075]

[Table 5]

[0076]

[Table 6]

However, d ₁ is the distance from the arc tube to the adjacent conductor located closer to the arc tube, and d ₂ is the distance from the arc tube to the adjacent conductor located farther from the arc tube. The separation distance.

Of course, even a combination of the relationship of the distances d ₁ and d ₂ from the arc tube to the adjacent conductor and the relationship of the lengths of the adjacent conductors shown in Tables 3 and 4 above, Even if a combination of pressure relationships of different xenon gas is used, Φ
> 10% can be realized.

The proximity conductors 17a and 17b may be made of bimetal as in the ninth embodiment of the present invention shown in FIG. 12, and in this way the light distribution of the lamp can be improved. .. The various effects described above can be obtained not only in the intersecting arc tubes 5a and 5b but also in the arc tubes 5a and 5b arranged in parallel. 13 and 14 show a tenth embodiment of the present invention. The tenth embodiment ensures the lighting control of the arc tubes 5a and 5b by setting the intersection angle of the arc tubes 5a and 5b.

That is, according to the inventor of the present application, the high-pressure discharge lamp with the adjacent conductors 17a and 17b having different polarities is
It has been found that if the influence of the electric field due to the electrodes 6 of the adjacent arc tubes 5a and 5b is reduced, the switching by the above-mentioned pulse becomes more reliable. Specifically, as shown in FIG. 5, the outer diameter D of the larger one of the two arc tubes 5a and 5b is set to the outer diameter D of the larger arc tube 5a, 5b.
Minimum value of the distance d between the surfaces of a and 5b, arc tubes 5a and 5b
When the intersection angle is 2θ, d ≦ 3 / 2D and D / 3U ≦
When sin θ <3D / U, switching by pulse was more reliable.

Straight tube type outer tube 1 having an outer diameter of 48 mm and a total length of 290 mm
In addition, the tube length 112mm, the outer diameter of 8.8mm arc tube 5a, 5
b (with 50 Torr xenon gas inside and 20
20 wt% Na-Hg amalgam (20 mg is encapsulated) are housed in a crossed state, and close conductors 17a and 17b made of Mo wire having a length of 33 mm are closely arranged near the electrodes. As a result of investigating the starting deviation ratio by changing the arc tube interval and the arc tube crossing angle using an electric lamp, the effects were confirmed as shown in Tables 7 and 8.

[0082]

[Table 7]

[0083]

[Table 8]

That is, looking at Tables 7 and 8, d ≦
At an interval of 13.2 (3 / 2D), the intersection angle 2θ is 3 °.
At (sin ^-1 D / 3U) to 27 ° (sin ^-1 3D / U), the deviation in starting could be suppressed within 5% up to 2400 h.

Moreover, according to the high-pressure discharge lamp in which the deviation of the starting is suppressed, the uniformity of the light distribution on the plane α perpendicular to the tube axis of the outer tube 1 as shown in FIG. 13 is within 10%. .. In addition, as shown in FIG. 14, the deviation of the optical axis of the high pressure discharge lamp when it is housed in the reflective shade 65 is also within 20 deg.

Further, in the transparent outer tube 1, D = 6 mm, 12 mm, 1
4mm, U = 70mm, 150mm, 190mm arc tube 5a,
Even a high pressure discharge lamp containing a 5b, likewise in the range of ^{d ≦ 3 / 2D, sin -1} 3D / 3 2θ from sin ^-1 D / 3U
At the value of, excellent characteristics were obtained. In addition, it was found that when the outer tube 1 was subjected to a diffusion treatment and housed in the B valve, both the uniformity and the deviation of the optical axis were further improved. The present invention is not limited to the high-pressure sodium lamp, and can be implemented with a metal halide lamp, a high-pressure mercury lamp, or the like. Further, the proximity conductor of the present invention is not limited to being arranged on the outer surface of the arc tube along the axial direction, but may be spirally wound on the outer surface of the arc tube.

Furthermore, in the case where a metal member such as a support wire supporting the arc tube is close to the arc tube,
The metal member such as the support wire may be used also as the close conductor, and in this case, the separate close conductor is not necessary.

[0088]

According to the first to fifth aspects of the present invention, the two arc tubes housed in the outer tube can be started with a probability of 50%. Moreover, this starting probability can be maintained until the end of life.

Therefore, it is possible to prevent only one side of the arc tubes from being unevenly lit, and because of the equal usage frequency of both arc tubes, problems such as early deterioration of one arc tube are resolved and the life is extended. It can be doubled, and the function of instantaneous relighting can be surely exhibited until the end of its life. In addition to these effects, the third to fifth aspects can further secure the starting probability of 50%.

[Brief description of drawings]

FIG. 1 is an overall view of a high-pressure sodium lamp showing a first embodiment of the present invention, where (A) is a front view and (B) is a side view.

FIG. 2 is a circuit configuration diagram of the same embodiment.

FIG. 3 is a waveform diagram showing a pulse generation situation of the embodiment.

FIG. 4 is a circuit configuration diagram of a high-pressure sodium lamp with a built-in starter showing a second embodiment of the present invention.

FIG. 5 is an overall view of a high-pressure sodium lamp showing a third embodiment of the present invention, where (A) is a front view and (B) is a side view.

FIG. 6 is a plan view of the same embodiment.

FIG. 7 is a waveform chart showing a pulse generation state which is a main part of a fourth embodiment of the present invention.

FIG. 8 is a waveform diagram showing a pulse generation situation which is a main part of a fifth embodiment of the present invention.

FIG. 9 is a waveform diagram showing a pulse generation state, which is a main part of a sixth embodiment of the present invention.

FIG. 10 is a circuit configuration diagram of a high-pressure sodium lamp with a built-in starter, which is a main part of a seventh embodiment of the present invention.

FIG. 11 is an overall view of a high pressure sodium lamp according to an eighth embodiment of the present invention, (A) is a front view and (B) is a side view.

FIG. 12 is an overall view of a high-pressure sodium lamp showing a ninth embodiment of the present invention, in which (A) is a front view and (B) is a side view.

FIG. 13 is a view for explaining the uniformity of light distribution in the tenth embodiment of the present invention.

FIG. 14 is a cross-sectional view schematically showing the discharge lamp housed in the reflector of the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Outer tube, 5a, 5b ... Arc tube, 6 ... Electrode, 9a, 9b
... Support wires, 17a, 17b ... Proximity conductors, 22 ...
Starting pulse generation circuit section.

Claims (5)

[Claims] 1. An outer tube which accommodates two arc tubes which are started by applying high-voltage pulses whose polarities are reversed to each other, in a state where these arc tubes are electrically connected in parallel, Proximity conductors are provided respectively for starting assistance, and the proximity conductors attached to these arc tubes are electrically connected so that their polarities are different from each other. The difference between the discharge start voltage and the discharge start voltage for the high-voltage pulse on the other pole side is configured to be 10% or more with respect to the value of the smaller discharge start voltage of the two discharge start voltages. High-pressure discharge lamp characterized by being. 2. A plurality of arc tubes whose lighting is controlled by a starting pulse, proximity conductors attached to the arc tubes, which are biased with electric potentials having mutually different polarities, and an alternating current supplied to these arc tubes. A power source and a pulse that oscillates on both sides of the alternating power source at predetermined intervals are superimposed on a sine wave, and the higher peak value on the both sides is V
_{H H} and the lower one is V _L , V _H > V _L × 1.1, and a starting circuit unit for generating a starting pulse having a pulse width of 1 μs or more at a 90% position of V _H. Characteristic high-pressure discharge lamp. 3. The high pressure discharge lamp according to claim 2, wherein the starter circuit unit superimposes a pulse oscillating on both sides of the sine wave on each half cycle of the AC power supply. 4. The high pressure discharge lamp according to claim 2, wherein the starting circuit unit superimposes a pulse oscillating on both sides of the sine wave at each of a plurality of cycles of the AC power supply. 5. The high-pressure discharge lamp according to claim 2, wherein the starting circuit unit superimposes a pulse oscillating on both sides on a sine wave a plurality of times in a predetermined cycle of the AC power supply. .