JPH09115481A - Electrodeless discharge lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp whose starting characteristic is improved and which can restrain devitrification of a light emitting tube and an increase in starting voltage caused by reaction between the light emitting tube and a sealing substance at lighting time. SOLUTION: This electrodeless discharge lamp is provided with an airtight light emitting tube 1 formed of a light transmissive material of a metallic oxide, and a light emitting substance containing at least one or more kinds of rare earth metal halogen compounds is sealed in its light emitting tube 1. In this case, a promotive substance to easily promote a halogen cycle caused in the vicinity of a light emitting tube inner wall is sealed in the light emitting tube 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp, and more particularly to an electrodeless metal vapor discharge lamp in which an effective filling material is enclosed in the arc tube.

[0002]

2. Description of the Related Art Generally, in a metal vapor discharge lamp using a metal halide as a light emitting substance, the temperature of the light emitting tube becomes high during lighting, so that the light emitting material and the light emitting tube which are enclosed react with each other, and There is a problem that discoloration or devitrification phenomenon occurs due to crystallization of the material of the arc tube, which lowers the light transmittance of the arc tube and shortens the lamp life.

In addition, the halogen of the metal halide which is melted into the arc tube or reacts with the arc tube and disappears causes a non-lighting or extinguishing phenomenon due to an increase in the starting voltage or the lamp voltage. There is also a problem of shortening the lamp life.

In order to solve these problems, a method of prolonging the life of a metal vapor discharge lamp with an electrode has been proposed by adjusting the composition of the material enclosed in the arc tube. For example, Japanese Unexamined Patent Publication No. 6-111769 discloses a means for preventing blackening by an electrode by paying attention to a halogen cycle in an arc tube and adding excess halogen.

Therefore, in order to prevent the reaction between the luminous substance and the arc tube by utilizing the halogen cycle, we have used the conditions described in the above-mentioned Japanese Patent Laid-Open No. 6-111769 to introduce an excess of halogen in a gas state in the arc tube. In an attempt to light an electrodeless discharge lamp that contains a lamp, the halogen that has a strong electron affinity is excessively present in the arc tube. It was difficult, and it was found that the luminous flux value during lighting was low.
Further, when the excess halogen is sealed in the state of the metal halide, the difficulty of starting is improved, but the decrease of the luminous flux during lighting cannot be prevented.

From these results, it was found that the method of promoting the halogen cycle for preventing the blackening of the arc tube by the electrodes in the electrode-equipped metal vapor discharge lamp is not suitable for the electrodeless metal vapor discharge lamp.

Japanese Patent Application Laid-Open No. 62-43058 discloses, as an example in which an electrodeless metal vapor discharge lamp is filled with an excess of halogen, sodium iodide is used as a luminescent material and mercury iodide is used as an excess of halogen. There is. In this structure, sodium in the vicinity of the wall of the arc tube is converted to sodium iodide by excess halogen, and if the sodium is left as it is, the D line of sodium generated at the arc center in the arc tube is self-absorbed and the efficiency is lowered. Prevent that.

When mercury iodide is used as a halogen cycle promoting substance in an electrodeless metal vapor discharge lamp using a rare earth metal halide as a light emitting substance, it is difficult to start because mercury iodide has a high vapor pressure. However, there is a problem that the luminous flux amount at the time of lighting becomes lower than that when mercury iodide is not enclosed even after starting.

Further, JP-A-5-217561 discloses an electrodeless metal vapor discharge lamp using neodymium, which is one of rare earth metals, as a light emitting substance.
When a rare earth metal compound is used as the light emitting material and the arc tube is formed of a metal oxide, the arc tube and the rare earth metal react with each other depending on the temperature during lighting to form a composite oxide. In the case of an electrodeless metal vapor discharge lamp, the above-mentioned reaction is more vigorous than the arc of a metal vapor discharge lamp with an electrode because the arc generated in the arc tube is closer to the inner wall of the arc tube.

Therefore, in the electrodeless metal vapor discharge lamp using a rare earth metal halide as the light emitting material, there remains a problem that the complex oxide is produced by the above reaction and the halogen remaining by the reaction makes starting difficult. If no measures are taken, this deterioration of startability cannot be improved.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and its object is to improve the starting characteristics and to improve the starting characteristics by reacting the arc tube with the encapsulating substance during lighting. An object of the present invention is to provide an electrodeless discharge lamp capable of suppressing devitrification of an arc tube and increase in starting voltage that occur.

[0012]

In order to solve the above problems, the present invention comprises an airtight arc tube formed of a translucent material of a metal oxide, and at least one or more rare earth elements are contained in the arc tube. In an electrodeless discharge lamp in which a light-emitting substance containing a metal halide is sealed, a promoting substance for facilitating a halogen cycle that occurs near the inner wall of the discharge tube is sealed in the discharge tube.

The operation will be described in detail below. Taking quartz as an example of the arc tube made of a metal oxide, when a rare earth metal is used as a light emitting substance, the rare earth metal ion and quartz react with each other to cause devitrification. Further, since the rare earth metal is enclosed in the arc tube in the form of a metal halide, when the rare earth metal reacts with quartz and the rare earth metal is lost, the halogen remains in the arc tube and the electron affinity of the halogen is strong.
This will increase the starting voltage or lamp voltage. These phenomena lead to a reduction in lamp life. As another example of an arc tube made of a metal oxide, it has been reported that a rare earth metal reacts with alumina ceramics even when alumina ceramics is used.

The metal halide enclosed in the arc tube is dissociated into a metal and a halogen at a high temperature portion and is bonded to the metal halide at a low temperature portion, which causes a halogen cycle, and the metal is excited and emits light at a high temperature portion. . By utilizing this halogen cycle, the state of the metal near the tube wall in the electrodeless metal vapor discharge lamp is changed from the state of highly reactive metal ions to the state of less reactivity, that is, the state of metal halides. can do. However, depending on the amount of halogen, the starting performance of the electrodeless metal vapor discharge lamp and the amount of luminous flux during lighting are reduced.

According to the present invention, the devitrification of the arc tube caused by the reaction between the arc tube and the encapsulating substance during lighting and the deterioration of the starting performance of the electrodeless metal vapor discharge lamp and the decrease in the luminous flux amount at the time of lighting are avoided. It is characterized in that a halogen cycle promoting encapsulation capable of suppressing an increase in the starting voltage is included.

If a large amount of halogen is present with respect to the metal ion, the metal ion has a high probability of collision with the halogen and is likely to be a metal halide (promoting the halogen cycle). Therefore, if a halogen is enclosed in addition to the metal halide to be enclosed in the arc tube, or if an enclosure containing a large amount of halogen in the arc tube during lamp operation is selected appropriately, the metal ion becomes a metal halide. The metal ion density near the inner wall of the arc tube is reduced, the reaction between the light emitting substance and the arc tube is suppressed, and the life of the lamp is extended. Further, the starting performance is improved as the amount of halogen existing as a gas in the arc tube is smaller while the light is off.

Needless to say, as a means for enhancing the above effect, the pressure of the rare gas filled in the arc tube together with the luminescent material is increased. Focusing on metal ions and metal atoms on the tube wall, the higher the pressure of the rare gas, the higher the probability of collision between the rare gas and the metal ions or metal atoms. That is, during repeated collisions, metal ions have a higher probability of encountering electrons and halogens, and become more stable metal atoms and metal halides with respect to the tube wall. Metal atoms also become metal halides.

Further, the number of collisions of electrons and metal ions flying from the plasma part in the arc tube toward the tube wall is also increased, so that the kinetic energy of each particle is reduced, and when the particles collide with the tube wall. , Damage to the tube wall is also effectively reduced.

The gas pressure to be filled in the arc tube varies depending on the type of the lamp, so it is difficult to limit it numerically, but it is desirable to set the gas pressure as high as possible within the allowable range in consideration of the performance of the lamp.

[0020]

1 is a schematic view showing an electrodeless discharge lamp according to the present invention together with a lighting device. The arc tube 1 which constitutes the electrodeless discharge lamp is hermetically formed of a material such as transparent quartz glass. A luminous substance and a rare gas are enclosed inside the arc tube 1. An induction coil 3 is wound around the outer circumference of the arc tube 1, and both ends thereof are connected to a high frequency generator 4. The high frequency generator 4 includes a high frequency generator 4a that generates a high frequency, an amplifier 4b that amplifies the output of the high frequency generator 4a, and a matching circuit 4c that is interposed between the amplifier 4b and the induction coil 3 to match impedance. To be done.

FIG. 2 is a schematic diagram showing an electrodeless metal vapor discharge lamp and a lighting device. The electrodeless metal vapor discharge lamp comprises an arc tube 1, an outer tube 5 and an induction coil 3. The arc tube 1 has a substantially cylindrical shape, and the space between the arc tube 1 and the outer tube 5 is evacuated.
The coldest spot temperature of the arc tube 1 is increased. Needless to say, the above configuration is an example of the embodiment according to the present invention, and the shape of the arc tube, the encapsulating material, and the like are not limited thereto.

(Embodiment 1) The electrodeless metal vapor discharge lamp according to this embodiment has a double tube structure as shown in FIG. 2, and the arc tube 1 is a cylindrical shape having a diameter of 30 mm and a height of 15 mm.
The arc tube 1 has neodymium iodide (Nd) as a light emitting substance.
15 mg of I ₃ ) and 5 mg of cesium iodide (CsI) are enclosed. This cesium iodide is used to form a complex halide with neodymium iodide and increase the vapor pressure of neodymium iodide (generally, an appropriate amount of cesium iodide forms a complex halide with a rare earth metal halide, Can increase the vapor pressure of metal halides). Further, as a halogen cycle promoting substance, a high vapor pressure, polyvalent halide is used in order to increase the halogen vapor pressure in the arc tube during lighting. As an example, 0.2 mg of antimony iodide (SbI ₃ ) is enclosed.

In the case of a lamp in which SbI ₃ is not enclosed, the initial starting voltage is 1.6600 lumens (lm) at an input power of 200 W and the initial starting voltage after lighting for 1 hour is 1.6 at the initial lighting.
Although it was kV, the luminous flux maintenance factor after lighting for 10,000 hours was 48%, and the starting voltage was 4.0 kV. Here, the starting voltage is a voltage between the coils of the induction coil 3 which is necessary when the lamp is turned on. On the other hand, in the lamp of the first embodiment, the input power is 200 W, the lumen is 15,100 lumens, and the initial starting voltage is 1.72 kV.
The luminous flux maintenance factor after lighting for 00 hours is 88%, the starting voltage is 1.78 kV, and it is understood that both the luminous flux maintenance factor and the starting voltage are improved.

Thus, antimony iodide (SbI ₃ )
By encapsulating SbI, the SbI
Due to the dissociation of ₃ , a large amount of iodine exists in the arc tube, that is, a large amount of iodine exists in the vicinity of the arc tube wall with respect to Nd ions, so that the halogen cycle near the arc tube wall is promoted and The reaction with the inclusion can be suppressed. The initial luminous flux was reduced by 9%. This is because the luminous volume of the discharge plasma was reduced by iodine. Therefore, the luminous flux maintenance factor can be greatly improved and the deterioration of startability due to lighting can be improved. I understood.

Further, antimony iodide produces a large amount of iodine due to dissociation during lighting and serves to promote the halogen cycle, but since the temperature is low during extinction, it exists in the arc tube in the state of antimony iodide and emits light. Since it does not exist in a gas state in the pipe, the starting performance is not deteriorated.

FIG. 8 shows the result of further detailed examination of the lamp used in Example 1 (result of lighting for 10,000 hours). In the lamp used in Example 1, the amount of antimony iodide as a halogen cycle promoting substance sealed in the lamp suitable for practical use was 0.07 mg to 1 mg in consideration of the starting voltage and the luminous flux value during lighting.

In Example 1, neodymium iodide was used as the light-emitting substance, high vapor pressure was used as the halogen cycle promoting substance, and antimony iodide was used as the polyvalent halide, but other rare earth metal halides or halogen cycle promoting substances were used. As a result of examining other metal halides, the following results were obtained.

The condition as the halogen cycle promoting substance is 40% in order to maintain the starting performance in consideration of the life.
A metal halide having a vapor pressure at 0 ° C. of not less than 1 Torr and not more than 1,000 Torr, the amount of which is enclosed in the arc tube is MXn (M: metal,
X: halogen, n: number of halogen), 5 × with respect to 1 mol of the rare earth metal contained in the luminescent material.
It was 10 ⁻³ / (n / 2) mol or more. Further, considering the luminous flux of the lamp during lighting, the amount sealed in the arc tube is 5 × 10 ⁻³ / (n / 2) mol or more and 1 × 10 ⁻¹ / (n / 2). It is desirable that the amount is not more than mol.

Example 2 First, the experimental results in this example will be described. A lighting experiment was conducted on lamps with a constant amount of neodymium iodide (NdI ₃ ) and different amounts of cesium iodide (CsI). The arc tube 1 used has a diameter of 30 m.
m is a cylindrical shape having a height of 15 mm, neodymium iodide to be enclosed in the arc tube 1 is a fixed amount of 15 mg, and three types of lamps having cesium iodide enclosed amounts of 5 mg, 10 mg, and 15 mg were prepared. .

As a result, after lighting for 1 hour, NdI ₃ :
Luminous flux 13,90 with a lamp of 15mg, CsI: 5mg
0 lumen, starting voltage 0.92kV, NdI ₃ : 15m
g, CsI: 10 mg lamp, initial luminous flux 14, 40
0 lumen, starting voltage 0.98kV, NdI ₃ : 15m
g, CsI: 15 mg lamp, initial luminous flux 13, 10
It was 0 lumen and the starting voltage was 1.00 kV.

After lighting for 10,000 hours, Nd
I ₃ : 15mg, CsI: 5mg lamp, luminous flux 7,
600 lumens, starting voltage 2.45 kV, NdI ₃ : 1
5mg, CsI: 10mg lamp, luminous flux 11,50
0 lumen, starting voltage 2.6kV, NdI ₃ : 15m
g, CsI: 15 mg, the luminous flux was 9,500 lumens, and the starting voltage was 2.05 kV.

Graphing the above results, FIG. 5 and FIG.
become that way. 5 is a graph showing the luminous flux and the starting voltage after lighting for 1 hour, and FIG. 6 is a graph showing the luminous flux and the starting voltage after lighting for 10,000 hours.

As is clear from these graphs, the luminous flux shows the maximum value when the amount of CsI is about 10 mg. This is because CsI has the effect of increasing the plasma volume in the arc tube, but when the enclosed amount is large, the luminous flux of the CsI itself falls in the infrared region, so that the luminous flux falls.

Regarding the starting voltage, the larger the amount of CsI, the smaller the increase in the starting voltage. This is because as the amount of CsI increases, the amount of iodine with respect to Nd in the arc tube increases, the halogen cycle is promoted, and Cs has less reactivity with the arc tube.

Thus, considering the deterioration of luminous flux and the deterioration of startability, it is considered appropriate that the CsI amount is 8 to 20 mg. Similar results were obtained with other rare earth metal halides. This amount of CsI is 1
It has been found that it is preferable to set it to 1.00 to 2.70 mol in terms of mol.

(Embodiment 3) In the present embodiment 3, xenon (Xe) gas 100 Torr, neodymium iodide (NdI ₃ ) 15 mg which is a rare earth metal halide as a light emitting material, and iodide are provided inside the arc tube 1. Cesium (CsI) 5
mg, and iodine gas at 0.5 Torr (N
dI ₃ (corresponding to 5.7 × 10 ⁻³ mol with respect to 1 mol).

Next, the results of the lighting test using the lamp of the third embodiment and the lamp of the comparative example in which iodine gas is not enclosed will be described.

In the case of the lamp of the comparative example, at the time of initial lighting (lighting for 1 hour), input power 200 W, 16,600 lumens, initial starting voltage (induction coil 3 necessary for lamp lighting)
The voltage between the coils) was 1.6 kV, but
The luminous flux maintenance factor after lighting for 0 hours was 48%, and the starting voltage was 4.0 kV.

On the other hand, in the lamp of the third embodiment, at the time of initial lighting (lighting for 1 hour), the input power is 200 W and the power is 15,4.
At 00 lumens, the initial starting voltage is 1.68 kV, and the luminous flux maintenance rate after lighting for 10,000 hours is 88%,
The starting voltage was 1.75 kV, which shows that both the luminous flux maintenance factor and the starting voltage were improved.

As described above, by enclosing the iodine gas, a large amount of iodine is present near the inner wall of the arc tube 1 while the lamp is lit, and the halogen cycle near the arc tube wall is promoted, so that the arc tube and the enclosure are separated. The reaction of was able to be suppressed. The initial luminous flux was reduced by 7%. This is because the luminous volume of the discharge plasma was reduced by iodine, so that the luminous flux maintenance factor could be greatly improved and the startability could be improved.

The larger the amount of enclosed iodine is, the more easily the halogen cycle is promoted and the deterioration is reduced, but the problem that the luminous flux value becomes small remains. From the experimental results, it was found that the reaction between the arc tube and the inclusions can be suppressed and the initial luminous flux can be suppressed by one digit% by setting the amount of the enclosed iodine to 1 to 2 Torr.

FIG. 7 shows the result of further detailed examination of the lamp used in Example 3 (result of lighting for 10,000 hours). In the lamp used in Example 3, the amount of iodine gas as a halogen cycle promoting substance sealed in the lamp in consideration of the starting voltage was 0.4 Torr or more. Also,
Considering the starting voltage and the luminous flux value during lighting, the amount of iodine gas as a halogen cycle promoting substance sealed in the lamp is
It was from 0.4 Torr to 8.8 Torr.

As a result of trying other rare earth metal halides, considering the life and luminous flux, the rare earth metal 1
The halogen is 5.0 × 10 ⁻³ mol or more per mol.
It was found that it is sufficient to encapsulate 0 × 10 ^-1 mol or less.

(Embodiment 4) FIG. 3 and FIG. 4 show Embodiment 4, and in this embodiment, a portion 1 to be an arc tube.
Is a cylindrical shape having a diameter of 30 mm and a height of 15 mm, and a cylindrical auxiliary tube 6 having a diameter of 5 mm and a length of 10 mm and a support rod 9 are provided at the substantially center of the bottom surface thereof to form a luminous tube 1.
As shown in FIG. 4A, the auxiliary pipe 6 and the auxiliary pipe 6 communicate with each other at a joint to form the same airtight space.

In the airtight space thus constructed, 15 mg of neodymium iodide (NdI ₃ ) which is a rare earth metal halide and 5 m of cesium iodide (CsI) are used as light emitting substances.
g was enclosed so that it was present in the auxiliary tube 6. As a starting gas, 100 Torr of xenon (Xe) gas was filled.

Next, as shown in FIG. 4A, the auxiliary pipe 6
When the coil 7 wound around the outer periphery of the auxiliary lamp 6 was turned on at an input power of 300 W for 1 hour, as shown in FIG. 4 (b), the devitrification phenomenon in which the inner wall of the coil winding portion of the auxiliary tube 6 became cloudy (in the figure, , Indicated by reference numeral 8) was observed. It was confirmed by subsequent analysis that free iodine was generated at the same time. Needless to say, the amount of generated free iodine is generated in such an amount that the lamp can be started.

Next, as shown in FIG. 4 (c), the auxiliary pipe 6
The joint portion between the arc tube 1 and the arc tube 1 is sealed by a burner so that the airtight space is only the part of the arc tube 1 having a diameter of 30 mm and a height of 15 mm. Incidentally, neodymium iodide at the time of sealing,
It goes without saying that cesium iodide and iodine generated by the previous lighting are enclosed in the arc tube 1.

The lighting test results of the thus manufactured lamp of Example 4 and the lamp manufactured as a comparative example in which iodine gas was not sealed are as follows.

In the case of the lamp of the comparative example, at the time of initial lighting for 1 hour, the input power was 200 W, 13,600 lumens, and the initial starting voltage (the coil-to-coil voltage of the induction coil 3 necessary for lighting the lamp) was 1.5 kV. However, the luminous flux maintenance factor after lighting for 10,000 hours was 57%, and the starting voltage was 4.
It was 0 kV.

On the other hand, in the lamp of Example 4, the input power was 200 W, the lumens were 12,700 lumens, the initial starting voltage was 1.6 kV, and the luminous flux maintenance factor after lighting for 10,000 hours was 88%, and the lamps were started. The voltage was 1.9 kV, which shows that both the luminous flux maintenance factor and the starting voltage were improved.

As a result of examining the amount of generated iodine gas, FIG.
The embodiment 8 is also performed by controlling the area 8 where the devitrification phenomenon occurs as shown in (b) (changing the size of the auxiliary pipe 6 and the number of windings of the coil 7 wound around the outer pipe 6). The same effect as in Example 3 was obtained. In addition, in the case of Example 4, since iodine gas can be generated after the lamp is formed without providing an iodine gas introduction path in the lamp manufacturing apparatus, the iodine can be easily handled.

As described above, in the case of Example 4, the same effect as that of Example 1 was obtained. Further, in the case of the fourth embodiment, there is also a feature that the method of generating iodine can be simplified. In addition,
The lamp of Example 4 showed the result of lighting by the method shown in FIG. 3 (without the outer tube), but it can be applied to the double tube method provided with the outer tube shown in FIG. 2 like the other Examples. Needless to say.

(Fifth Embodiment) In the fifth embodiment, the structure of the lighting device is the same as that of the above-mentioned embodiments. The difference from the other examples is that the arc tube 1 is a spherical arc tube having a diameter of 27 mm and made of quartz.

In the arc tube 1, in addition to Xe gas of 200 Torr, NdI ₃ which is a rare earth metal light emitting material is used as a light emitting material.
15 mg and CsI 5 mg are enclosed. Further, as a halogen cycle promoting substance, antimony iodide (SbI
₃ ) 0.2 mg is enclosed. In this example, 2 mg of sodium iodide (NaI) was added to the red light emitting substances, sodium halide and lithium halide, in order to further reduce the color temperature.

This lamp was initially lit (lighted for 1 hour) as in the other examples (input was 180 W),
As a result, the characteristics of the lamp before adding sodium iodide were as follows: luminous flux: 13,700 lumens, color temperature: 6,500.
K, average color rendering index: 82, but the characteristics of the lamp after addition of sodium iodide are: luminous flux: 14,600 lumens, color temperature: 5,800K, average color rendering index: 80, lowering the color temperature. I was able to do it.

On the other hand, the initial starting voltage at the time of initial lighting (lighting for 1 hour) was 1.7 kV, but when the lighting time was 500 hours, the starting voltage increased to 4.3 kV. This is because when 0.2 mg of antimony iodide (SbI ₃ ) which is a halogen cycle promoting substance enclosed in order to suppress the reaction between the rare earth metal halide and the arc tube, the reaction between the red light emitting sodium and the arc tube is caused. It is considered that sodium could not be suppressed and sodium dissolved into the arc tube, and the free iodine generated as a result increased the starting voltage.

Therefore, in order to suppress the reaction between sodium and the arc tube, an attempt was made to increase the amount of the halogen cycle promoting substance for the red light emitting substance. The same encapsulation material (Xe gas:
200 Torr, NdI ₃ : 15 mg, CsI: 5 mg, N
A lamp was prepared by further increasing the amount of antimony iodide (SbI ₃ ) which is a halogen cycle promoting substance by 0.4 mg in aI: 2 mg), and conducted a similar experiment to find that the lamp characteristics during initial lighting (one hour lighting) Is the luminous flux: 13,500
Lumen, color temperature: 5,700K, average color rendering index: 8
It was 0. Further, the initial starting voltage is 1.72 kV, and even when the lighting time is 500 hours, the starting voltage is 1.
As a result of continuing the lighting experiment without change of 72 kV, 1
The starting voltage is 1.81k even after lighting for 10,000 hours.
Good results were obtained with V and a luminous flux maintenance factor of 87%.

Next, antimony iodide (Sb) is additionally used as a halogen cycle promoting substance for red light emitting substance.
I ₃ ) 0.4 mg instead of indium iodide (InI)
A configuration using 0.3 mg will be described. The characteristics of this lamp during initial lighting (lighting for 1 hour) are: luminous flux: 15, 5
The value was 00 lumen, the color temperature was 5,500 K, and the average color rendering index was 86. The initial starting voltage is 1.76k.
The voltage was V, and after 10,000 hours of lighting, good results were obtained with a starting voltage of 1.83 kV and a luminous flux maintenance factor of 87%. Compared with the case of 0.4 mg of antimony iodide, almost the same good results were obtained with respect to the starting voltage, and the luminous flux and the average color rendering index were improved.

Similar results were obtained when other rare earth metal halides or lithium halides were used as the red light emitting material. Summarizing these results, 1
In order to obtain a similar increase in the starting voltage even when the lamp is turned on for more than 10,000 hours, and in order to make it similar to the other examples, a halogen cycle promoting substance is added to the amount described in claim 2 for the rare earth metal. , A red light emitting substance may be newly added. At this time, it is necessary to consider that if the halogen cycle promoting substance for the red light emitting substance is filled in too much, the luminous flux amount during lighting decreases.

The conditions for the halogen cycle promoting substance for the red light emitting substance are that the vapor pressure at 400 ° C. is 1 Torr or more,
It is a metal halide of 1000 Torr or less, and its encapsulation amount is red when the composition of the metal halide is expressed as MXn (M: metal, X: halogen, n: number of halogen) in order to prevent an increase in starting voltage. 1 per 1 mol of sodium or lithium contained in the luminescent material
It is necessary to additionally enclose at least 10 ⁻³ / (n / 2) mol. Further, when considering the luminous flux amount during lighting, the total of the promoting substance for rare earth metal and the promoting substance for red light emitting substance is 1 × 10.
It is desirable that the amount be ^-1 / (n / 2) mol or less.

(Embodiment 6) The experiment results of this embodiment 6 will be described.

The arc tube 1 has a diameter of 30 mm and a height of 15 mm.
In the arc tube 1, neodymium bromide (NdBr ₃ ) 11 mg and neodymium iodide (NdI) were used as luminous substances in the arc tube 1.
₃ ) 15 mg and cesium iodide (CsI) 5 mg were enclosed. This lamp is lit with an input power of 200 W by a lighting device as shown in FIG. 2, and a lamp (NdI ₃ :
30 mg, CsI: 5 mg) and the luminous flux and starting voltage were compared and examined. In addition, NdBr ₃ : 11 mg and Nd
I ₃ : 15 mg was almost the same number of moles, and the number of moles of Nd in the two types of trial-produced arc tubes was the same.

In the case of the lamp of Example 6, the luminous flux is 14,800 lumens and the starting voltage is 1.01 kV after being lit for 1 hour.
Met. It continues to light up and 10,000 hours later,
Luminous flux is 10,900 lumens, starting voltage is 1.71 kV
Met. On the other hand, in the case of the lamp of the comparative example, the luminous flux is 13,000 lumens and the starting voltage is 1.01 k after 1 hour of lighting.
However, after 10,000 hours, the luminous flux was 7,8
The starting voltage was 00 lumens and 2.46 kV.

From these results, the lamp of Example 6 is
It can be seen that the degree of deterioration of both the luminous flux and the starting voltage is small. This is because the lamp of Example 6 is a halide.
Since iodide and bromide are encapsulated and vaporize independently during lamp operation, iodine and bromine exist independently, and as a result, the total number of halogens present in the arc tube is (NdI ₃ + CsI). ) Than (NdI ₃ + N
The amount of dBr ₃ + CsI) is larger, and the halogen cycle is accelerated.

[0065]

As described above, the present invention is provided with an airtight arc tube formed of a translucent material of a metal oxide, and light emission containing at least one kind of rare earth metal halide in the arc tube. In an electrodeless discharge lamp in which a substance is encapsulated, by encapsulating a promoting substance that facilitates the halogen cycle that occurs near the inner wall of the arc tube in the arc tube, the starting characteristics are improved and the arc tube and the encapsulating material are improved during lighting. It is possible to provide an electrodeless discharge lamp capable of suppressing the devitrification of the arc tube and the increase in the starting voltage caused by the reaction with.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an electrodeless discharge lamp according to the present invention together with a lighting device.

FIG. 2 is a schematic view showing an electrodeless metal vapor discharge lamp and a lighting device according to the present invention.

FIG. 3 is a schematic diagram showing an electrodeless metal vapor discharge lamp and a lighting device according to a fourth embodiment.

FIG. 4 is a schematic diagram showing a manufacturing process of an arc tube according to Example 4, (a) showing a state in which halogen is generated, (b).
Shows the state after generating halogen, and (c) shows the state after sealing the auxiliary tube.

FIG. 5 is 1 when the CsI amount according to the second embodiment is changed.
It is a graph which shows the luminous flux and lighting voltage after lighting for a while.

FIG. 6 is 1 when the CsI amount according to the second embodiment is changed.
It is a graph which shows the luminous flux and the starting voltage after lighting for 10,000 hours.

FIG. 7 is a graph 1 when the amount of I ₂ according to Example 3 is changed.
It is a graph which shows the luminous flux and the starting voltage after lighting for 10,000 hours.

FIG. 8 is a graph showing a luminous flux and a starting voltage after lighting for 10,000 hours when the SbI ₃ amount according to Example 1 was changed.

[Explanation of symbols]

 1 arc tube 3 induction coil 4 high frequency generator 5 outer tube 6 auxiliary tube 7 coil

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shingo Higashisaka 1048, Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Works Co., Ltd. (72) Koji Nishioka, 1048, Kadoma, Kadoma City, Osaka Matsushita Electric Works Co., Ltd.

Claims (12)

[Claims] 1. An electrodeless device comprising an airtight arc tube formed of a translucent material of a metal oxide, and a light emitting substance containing at least one or more kinds of rare earth metal halides enclosed in the arc tube. In the discharge lamp, an electrodeless discharge lamp characterized in that a promoting substance for facilitating a halogen cycle occurring near the inner wall of the arc tube is enclosed in the arc tube. 2. The accelerating substance is a metal halide having a vapor pressure at 400 ° C. of 1 Torr or more and 1000 Torr or less, and the composition of the halide is MXn (M: metal, X: halogen, n: number of halogens). )), The metal halide is 5 × 10 ⁻³ / (n / 2) mol or more with respect to 1 mol of the rare earth metal contained in the luminescent material. Electrodeless discharge lamp. 3. The accelerator is 5 × 10 ⁻³ / (n /
The electrodeless discharge lamp according to claim 2, which is a metal halide having a molar ratio of 2) or more and 1 × 10 ^-1 / (n / 2) or less. 4. The electrodeless discharge lamp according to claim 1, wherein the metal halide that is the accelerating substance is antimony iodide (SbI ₃ ). 5. The accelerating substance is cesium halide, and cesium halide is contained in an amount of 1.00 to 2.70 mol with respect to 1 mol of the rare earth metal contained in the luminescent substance. Item 2. The electrodeless discharge lamp according to Item 1. 6. The accelerating substance is a halogen gas simple substance of iodine, bromine, chlorine, or a mixed gas thereof, and a total of 5 × 10 5 with respect to 1 mol of the rare earth metal contained in the luminescent substance.
^{3. The} electrodeless discharge lamp according to claim 1, which is ^-3 mol or more and 1 × 10 ^-1 mol or less. 7. The electrodeless discharge lamp according to claim 6, wherein the halogen gas, which is the accelerating substance, is generated at the initial lighting of the electrodeless discharge lamp. 8. The luminescent material is added with at least one or more of sodium and lithium alone or halogen compounds of each of them, which lowers the color temperature for red material, and the accelerating material is added for red material. A metal halide having a vapor pressure at 400 ° C. of not less than 1 Torr and not more than 1000 Torr, the composition of the halide being MXn
When expressed as (M: metal, X: halogen, n: number of halogen), it is 1 × 10 ⁻³ / with respect to sodium, lithium, or a total of 1 mol thereof contained in the red light emitting substance.
2. The electrodeless discharge lamp according to claim 1, wherein a metal halide having a molar ratio of (n / 2) or more is additionally enclosed. 9. The promoting material is 1 × 10 ⁻³ / (n /
The electrodeless discharge lamp according to claim 8, which is a metal halide having a molar ratio of 2) or more and 1 × 10 ^-1 / (n / 2) or less. 10. The antimony iodide is additionally encapsulated as the accelerating substance.
An electrodeless discharge lamp as described. 11. The indium iodide is additionally encapsulated as the accelerating substance.
An electrodeless discharge lamp as described. 12. The metal according to claim 1, wherein the rare earth metal halide of the light emitting substance contains at least two kinds of metal halides among halides of iodine, bromine and chlorine. Steam discharge lamp.