JP2005259691A - Ceramic metal halide lamp, and illumination device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic metal halide lamp keeping high lamp power factor and efficiency even if a ballast for high pressure mercury lamp is used. <P>SOLUTION: The ceramic metal halide lamp has a light emitting tube containing mercury, rare gas, thallium halide, sodium halide, and at least one kind selected from dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide as sealed materials. Molar number of cesium element in cesium halide contained in the light emitting tube is 10% or less of the molar number of the metal elements of dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide. The tube wall load of the light emitting tube is made 22 to 25 W/cm<SP>2</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a metal halide lamp using a translucent ceramic for an arc tube, a method of using the same, and a lighting fixture using the same.

  As a prior art related to the present invention, one or more kinds of inert gas, mercury, thallium iodide, dysprosium iodide, holmium iodide and other rare earth metal iodides are enclosed in an arc tube made of quartz. There is a thing (refer patent document 1). Further, there is known a translucent ceramic arc tube in which iodide such as holmium, dysprosium, thulium, sodium, thallium, cesium and the like are sealed together with a starting rare gas and mercury (see Patent Document 2).

In the metal halide lamp described in Patent Document 1, the tube wall load of the arc tube is 10 to 12.5 W / cm ² , the luminous efficiency is 78 to 82.5 lm / W, and the average color rendering index Ra is 70 to 80. . Since this lamp uses quartz for the arc tube, the tube wall load cannot be increased to 20 W / cm ² or more in order to avoid the reaction between the encapsulated material and the quartz material. For this reason, there is a drawback that the luminous efficiency and the average color rendering index Ra are inferior. Therefore, this lamp is not suitable for indoor lighting applications.

The metal halide lamp described in Patent Document 2 contains dysprosium iodide, thulium iodide, holmium iodide, thallium iodide, sodium iodide, and cesium iodide together with a rare gas and mercury in a ceramic arc tube. . Furthermore, the tube wall load is set to 29.9 W / cm ² .

  Until now, in metal halide lamps, ballasts have been designed for each lamp. That is, there is no versatile ballast for metal halide lamps. As a result, there is a problem that the ballast becomes expensive because the mass production effect does not work. On the other hand, in ballasts for high-pressure mercury lamps, the standards are determined by Japanese Industrial Standards (JIS) and the like, and versatile ballasts in accordance with the standards are mass-produced. As a result, due to mass production effects, ballasts for high pressure mercury lamps are cheap. Moreover, a large amount of standard products are on the market.

  If a ballast for a high-pressure mercury lamp can be used with a metal halide lamp, there is an advantage that the metal halide lamp can be used at low cost. In addition, there is an advantage that a metal halide lamp can be used as it is in an illumination device for a high-pressure mercury lamp already used in the market.

However, when a conventional metal halide lamp is used in a ballast for a high-pressure mercury lamp, there is a problem that a sufficiently high lamp power factor cannot be obtained. Here, the lamp power factor is a value obtained by the following equation.

Lamp power factor = lamp power W / (voltage applied to the lamp × current flowing in the lamp)

In addition, as a material of the arc tube of the metal halide lamp, quartz or translucent ceramic is generally used. A metal halide lamp using a translucent ceramic is called a ceramic metal halide lamp. Quartz is less heat resistant than translucent ceramics. Therefore, when quartz is used, the upper limit of the tube wall load is about 20 W / cm ² . However, in order to improve the lamp efficiency, it is necessary to further improve the tube wall load. In such a case, a translucent ceramic that has better heat resistance than quartz is used. However, the cost of translucent ceramic is higher than that of quartz. Thus, translucent ceramic is generally used in the lamp of the significantly higher wall loading ^{(50W / cm 2 ~60W / cm} 2 or so) than with quartz. The lamp efficiency means a luminous flux per electric power, and is expressed in units such as lm / W (lumen / watt).

  As described above, when a translucent ceramic is used, a high lamp efficiency is obtained by a high tube wall load. However, a high tube wall load causes a problem of a decrease in lamp power factor. In the case of using a ballast designed for the lamp, for example, in the case of an electronic ballast, such a problem does not occur because the ballast can be designed so that the lamp power factor is approximately 1. Moreover, even if it is a copper iron ballast, when using the ballast designed for the lamp, such a problem does not occur because the lamp power factor can be set high. However, when a ballast for a high-pressure mercury lamp is used for a metal halide lamp, the ballast cannot be optimally designed, and this reduction in lamp power factor becomes a serious problem of lamp extinction. In order to solve this problem, it is common practice to improve the lamp power factor by including cesium halide in the arc tube. In this case, the amount of cesium halide is halogenated relative to the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube. The number of moles of cesium element in cesium was adjusted to be 20% or more.

  However, it is required to further improve the lamp power factor and the lamp efficiency. However, when the tube wall load is increased, the lamp power factor is decreased, and when the tube wall load is decreased, the lamp efficiency is decreased. Therefore, there is a problem that even if the tube wall load is adjusted, a lamp having both a high lamp power factor and a high lamp efficiency cannot be obtained.

JP 52-31581 A JP 2001-266791 A

  An object of the present invention is to solve the above-described problems and provide a lamp having both high lamp power factor and high lamp efficiency even when a ceramic metal halide lamp is used in a ballast for a high-pressure mercury lamp. .

The first invention according to the present invention is as follows.
At least one of dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide;
mercury,
Noble gas,
In ceramic metal halide lamps equipped with arc tubes containing thallium halide and sodium halide as inclusions,
Cesium halide contained in the arc tube with respect to the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube The number of moles of the cesium element is 10% or less, and the wall load of the arc tube when the ceramic metal halide lamp is turned on by a test ballast for a high-pressure mercury lamp is 22 to 25 W / cm ^2. It is characterized by.

The first invention described above is based on the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube. The number of moles of the cesium element of the cesium halide contained in the lamp is 10% or less, and the wall load of the arc tube when the ceramic metal halide lamp is turned on by the test ballast for the high-pressure mercury lamp is 22-25 W / By combining with the cm ² , even if a ceramic metal halide lamp is used in a ballast for a high-pressure mercury lamp, it is possible to achieve both a high lamp power factor and a high lamp efficiency.

As described above, a ceramic metal halide lamp is generally tube wall loading have been used in the ^50W / cm ^{2 ~60W} / cm 2 area of about. When the tube wall load is in the vicinity of 50 W / cm ² , the amount of decrease in the lamp power factor due to the increase in the tube wall load is about the same when the amount of cesium halide in the arc tube is large and small. Accordingly, it has been considered that even if the amount of cesium halide is changed, “a lamp having both high lamp power factor and lamp efficiency cannot be obtained by adjusting the tube wall load”. However, the inventors' research has revealed that in the region where the tube wall load is 25 W / cm ² or less, the results near 50 W / cm ² give completely unexpected results. That is, in the vicinity of 50 W / cm ² , the decrease in the lamp power factor due to the increase in the tube wall load is the same between the case where the amount of cesium halide in the arc tube is large and the case where the amount is small. In the region of 25 W / cm ² or less, the difference in lamp power factor due to the difference in the amount of cesium halide is significantly reduced (see FIG. 5).

On the other hand, the degree of decrease in lamp efficiency due to a decrease in tube wall load is the same when the amount of cesium halide in the arc tube is large and small (see FIG. 4). As a result, the tube wall load is set to 22 to 25 W / cm ² , and the metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube The ceramic metal halide lamp was turned on by a ballast for a high-pressure mercury lamp by combining the number of moles of cesium halide contained in the arc tube with 10 moles or less with respect to the number of moles of Even in this case, a lamp having a high lamp power factor and a high lamp efficiency can be obtained. This was first discovered by the present inventors.

  The present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view showing an arc tube constituting a metal halide lamp of the present invention. In FIG. 1, reference numeral 1 denotes an arc tube made of a translucent alumina ceramic, and a thin tube portion 5 is provided at both ends thereof. A first electric introduction body 7 made of a heat-resistant metal whose thermal expansion coefficient approximates that of the thin tube portion 5 is inserted into the thin tube portion 5. A second electric introduction body 6 made of a heat-resistant metal is attached to the electric introduction body 7. Furthermore, an electrode core 3 having an electrode coil 2 is attached to the electrical introduction body 6. A part of the electrical introduction bodies 6 and 7 and a part of the thin tube portion 5 are airtightly fixed by a sealing material 9. 4 is an electrode 2nd coil, 10 is a spacer.

Here, the inner diameter and the length of the arc tube made of translucent alumina ceramic are set so that the tube wall load is 22 to 25 W / cm ² . The tube wall load is represented by a value obtained by dividing the lamp power by the arc tube inner area corresponding to the distance between the electrodes. “The arc tube inner area corresponding to the distance between electrodes” is defined as follows. A straight line is formed by connecting the centers of the tips of two electrodes facing each other in the arc tube. Of the planes perpendicular to the straight line, two planes including the centers of the tips of the two electrodes are selected. The area of the portion located between the two planes in the arc tube inner area is defined as “the arc tube inner area corresponding to the distance between the electrodes”. The reason for setting the lower limit of the tube wall load to 22 W / cm ² is as follows. When the tube wall load is less than 22 W / cm ² , the arc tube temperature does not rise sufficiently. As a result, the vapor pressure of the halide does not increase, so that high efficiency cannot be obtained. Furthermore, if the tube wall load is less than 22 W / cm ² , the average color rendering index (Ra) is less than 80, and high color rendering properties are lost.

  Inside the arc tube made of translucent ceramic thus configured is mercury, a rare gas for starting, and at least one of dysprosium halide, thulium halide and holmium halide as a luminescent substance. And thallium halide and sodium halide are enclosed. The optimum amount of luminescent material to be filled varies depending on the size of the lamp and the color temperature of the emission spectrum. The relationship between the size and color temperature of the lamp and the optimum amount of rare earth halide is as follows. The arc tube inner volume is represented by the arc tube volume corresponding to the distance between the electrodes. The “volume of the arc tube corresponding to the distance between electrodes” is defined as follows. A straight line is formed by connecting the centers of the tips of two electrodes facing each other in the arc tube. Of the planes perpendicular to the straight line, two planes including the centers of the tips of the two electrodes are selected. The volume of the portion located between the two planes in the arc tube inner volume is defined as “the arc tube inner volume corresponding to the distance between the electrodes”. That is, the gap located in the end direction from the tip of the electrode is excluded from the calculation of the inner volume because the inner diameter of the arc tube is reduced and the volume is very small.

<When color temperature is 3000K>
[Lamp size 190W]
The optimum enclosure amount of each rare earth halide is 3.5 × 10 ⁻⁶ mol / cm ^{3 to} 5.5 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 13 × 10 ⁻⁶ mol / cm ^{3 to} 33. The range of × 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 230W]
The optimum enclosure amount of each halide is 1.3 × 10 ⁻⁶ mol / cm ^{3 to} 2.5 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 13 × 10 ⁻⁶ mol / cm ³ to 18 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 270W]
The optimum enclosure amount of each halide is 4.0 × 10 ⁻⁶ mol / cm ^{3 to} 6.2 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 15 × 10 ⁻⁶ mol / cm ^{3 to} 35 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 360W]
The optimum enclosure amount of each halide is 1.0 × 10 ⁻⁶ mol / cm ^{3 to} 3.0 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 6 × 10 ⁻⁶ mol / cm ³ to 15 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

<When the color temperature is 4000K>
[Lamp size 190W]
The optimum enclosure amount of each rare earth halide is 5.0 × 10 ⁻⁶ mol / cm ^{3 to} 10.0 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 23 × 10 ⁻⁶ mol / cm ^{3 to} 55. The range of × 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 230W]
The optimum enclosure amount of each halide is 2.0 × 10 ⁻⁶ mol / cm ^{3 to} 5.0 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 8 × 10 ⁻⁶ mol / cm ³ to 18 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 270W]
The optimum enclosure amount of each halide is 3.0 × 10 ⁻⁶ mol / cm ^{3 to} 7.0 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 20 × 10 ⁻⁶ mol / cm ³ to 40 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

[Lamp size 360W]
The optimum enclosure amount of each halide is 1.0 × 10 ⁻⁶ mol / cm ^{3 to} 3.0 × 10 ⁻⁶ mol / cm ³ , and the total enclosure amount is 8 × 10 ⁻⁶ mol / cm ^{3 to} 20 ×. The range of 10 ⁻⁶ mol / cm ³ is preferable.

  When the amount of enclosure is smaller than the above range, the amount of the enclosure that acts effectively is reduced by so-called “scrolling” in which the enclosure enters the narrow tube portion. As a result, the vapor pressure of the halide does not increase sufficiently, making it difficult to obtain desired lamp characteristics. Moreover, when the amount of sealing becomes larger than this range, excess halide accumulates on the inner surface of the arc tube. Since the halide absorbs light, lamp efficiency decreases. Further, since the reaction between the halide and the arc tube member is accelerated, inconveniences such as shortening the lamp life occur.

  As the halide used as the light-emitting substance, at least one of dysprosium halide, thulium halide and holmium halide, erbium halide, and terbium halide is used. Among these, dysprosium halide, halogen More preferably, all three of thulium halide and holmium halide are encapsulated.

  As the light-emitting substance, the above-described halogen compounds are used. As the halogen, iodine I is preferable, and bromine Br may be contained in some cases.

  In addition, although the translucent alumina ceramic was demonstrated as an example as a material of an arc_tube | light_emitting_tube, it is not limited to this. For example, a translucent ceramic material such as yttrium oxide, magnesium oxide, or aluminum nitride is used.

  Further, the arc tube shown in FIG. 1 has a shape in which the thin tube portion 5 is attached via an end disk provided at the end of the large-diameter central main tube. However, the present invention is not limited to this. For example, it is a matter of course that a so-called integrally molded product having a shape in which the main tube portion and the thin tube portion are integrally formed may be used.

  Further, as the starting rare gas, commonly used neon, argon, xenon, krypton, or a mixed gas thereof can be used. Among them, it is preferable to use Ar gas of 3 to 10 KPa because the startability of the lamp is good.

  FIG. 2 is a schematic configuration diagram of the metal halide lamp of the present invention. 1 is a translucent ceramic arc tube having the above-described configuration, 11 is a hard glass outer tube, 12 is a support wire (also serving as an electrical conductor) for supporting the arc tube, and 14 is a high vacuum inside the outer tube. 16 is a starter auxiliary conductor for facilitating the start of the lamp, and 15 is a base. Since the lamp shown in FIG. 2 does not incorporate a starter in the outer tube, it is necessary to add a starter to the ballast. For example, if a starter is added to the ballast, the lamp shown in FIG. 2 can be lit with a ballast having a low secondary no-load voltage, such as a ballast for a mercury lamp.

  FIG. 3 shows an embodiment of the metal halide lamp of the present invention, which is different from FIG. In this example, a starter 13 made of a glow tube is built in the outer tube. When the starter 13 is built in the outer tube, the mercury lamp stabilizer can be used as it is. Therefore, it is possible to switch from illumination using a mercury lamp to illumination of a metal halide lamp only by exchanging the lamp. The starter 13 is not limited to a glow tube. For example, a starter composed of a series circuit of a bimetal switch and a resistor, or a non-linear capacitor may be used. In the ceramic metal halide lamp thus formed, the average color rendering index Ra is 80 or more and the color temperature is 3500 to 5000K.

Next, an example of a 360 W lamp will be described.
The arc tube 1 shown in FIG. 1 was manufactured. The arc tube 1 is made of a translucent alumina tube, and the inner diameter of the central portion is about 20 mm. Using five types of arc tubes, the inner dimensions of which are approximately 34, 36, 38, 40, and 42 mm, excluding the thin tube portion, five lamps were prototyped. At this time, the longer the inner dimension, the longer the interelectrode length, which is the distance between the tips of the left and right electrode cores 3. The length between the electrodes was about 19, 21, 23, 26 and 29 mm. Correspondingly, the tube wall load of the lamp when it is turned on with a test ballast for a 400 W high-pressure mercury lamp defined by JIS is about 30, 27, 25, 22 and 20 W / cm ² . The diameter of the electrode core 3 was about 0.9 mm, and the inner and outer diameters of the narrow tube portions 5 provided at both ends of the arc tube 1 were about 2 mm and about 4.5 mm, respectively. The first electric introduction body 7 was made of an alloy of Nb-1% Zr and had a diameter of about 0.7 mm and a length of about 15 mm. The second electric introduction body 6 is made of Mo and has a diameter of about 0.4 mm and a length of about 3 mm. A part of the first electricity introduction body 7 and the second electricity introduction body 6 is composed of 21.8% by weight of SiO ₂ , 16.8% by weight of Al ₂ O _3, and Y ₂ O on the inner surface of the end of the thin tube portion 5. ₃ It is brazed and fixed airtightly by a 61.4 wt% sealing material 9.

The thus sealed arc tube 1, _{DyI 3,} TmI 3 and HoI ₃ were respectively placed 2.0 × ^{10 -6} mol / cm ³ as a luminous material. Further, thallium iodide is added at a molar ratio of about 0.4 with respect to the total of the rare earth (Dy, Tm and Ho) halides, and sodium iodide is added at a molar ratio of about 2 with respect to the total of the rare earth halides. 0.0. Furthermore, argon was put into the arc tube 1 as a rare gas so that the partial pressure was 1.6 × 10 ⁴ Pa. Further, the amount of mercury put into the arc tube 1 was set to 64, 61, 58, 55 and 52 mg in order with respect to the arc tube 1 having an interelectrode length of about 19, 21, 23, 26 and 29 mm, respectively. As described above, 25 lamps of Example A according to the present invention were manufactured. Further, in the same manner as in Example A above, except that 10 mol% of cesium iodide was added to the total amount of rare earth halides contained in the arc tube and placed in the arc tube. Twenty-five lamps of Example B according to the invention were made. Further, a comparison was made in the same manner as in Example A above, except that 20 mol% of cesium iodide was added to the total amount of rare earth halides contained in the arc tube and placed in the arc tube. 25 lamps from Example C were made.

  As shown in FIG. 3, the arc tube 1 formed in this way is fixed in an outer tube 11 made of hard glass by an electric conductor / support 12 made of stainless steel. A starting auxiliary conductor 16 made of Mo wire having a diameter of about 0.2 mm is attached to the arc tube 1 and a starter 13 made of a glow tube is incorporated. This lamp can be easily lit with a mercury lamp ballast.

  The initial characteristics of the 75 lamps thus configured were measured. In these lamps, various characteristics at a constant power supply voltage of 200 V were measured using a test ballast for a high-pressure mercury lamp. Based on the obtained measurement data, the relationship between the tube wall load and the lamp efficiency is shown in a graph as shown in FIG. Further, the relationship between the tube wall load and the lamp power factor was as shown in FIG. 4 and 5, the case where 20% of cesium iodide is added is represented by ◆, the case where 10% is added, and the case where no cesium iodide is added are represented by ■. In the above comparative example, cesium iodide is used as the cesium halide sealed in the discharge tube, but the same result can be obtained by using a cesium halide other than cesium iodide. In the above experiment, a lamp of 360 W was used, but similar results can be obtained with other power, for example, a lamp of 100 to 1000 W.

  Further, among the above-mentioned 360 W lamps, the lamp of Example A that did not contain cesium iodide in the arc tube was subjected to a life test, and the results shown in FIGS. 6, 7, 8, and 9 were obtained. FIG. 6 shows the relationship between the tube wall load and the lamp voltage increase value after lighting for 12000 hours. Here, the lamp voltage increase value is represented by the difference between the lamp voltage after the life test and the lamp voltage before the life test in the life test. FIG. 7 shows the relationship between the tube wall load and the peak voltage after lighting for 12,000 hours. Here, in the lamp of the example after the above life test, the lamp voltage increases after starting the lamp, decreases after reaching the peak, and reaches a stable voltage value. That is, a voltage peak appears before the lamp voltage reaches the stable voltage value. The difference between the voltage value at the peak and the stable voltage value is called a peak voltage.

FIG. 8 shows the relationship between the tube wall load and the lamp turn-off rate after 12000 hours of lighting. The extinction is a phenomenon in which the lamp is not lit after starting, and the lamp is extinguished when the voltage required to maintain the lamp is higher than the voltage applied to the lamp. Furthermore, FIG. 9 shows the relationship between the lighting time and the luminous flux maintenance factor. 9, the data enclosed by dotted lines of the present invention product tube wall load 22~25W / cm ^2, the data surrounded by the solid line wall loading is a comparative example of a 30 W / cm ^2.

From the above data, the following became clear.
In the region where the tube wall load is 25 W / cm ² or less, it has been found that the results near 50 W / cm ² give completely unexpected results. That is, in the vicinity of 50 W / cm ² , the decrease in the lamp power factor due to the increase in the tube wall load is the same between the case where the amount of cesium halide in the arc tube is large and the case where the amount is small. In the region of 25 W / cm ² or less, the difference in lamp power factor due to the difference in the amount of cesium halide is significantly reduced (see FIG. 5). On the other hand, the degree of decrease in lamp efficiency due to a decrease in tube wall load is the same when the amount of cesium halide in the arc tube is large and small (see FIG. 4). On the other hand, when the tube wall load is smaller than 22 W / cm ² , the lamp efficiency is drastically lowered, which is not practical. Furthermore, as shown in FIG. 4, when the number of moles of the cesium element of the cesium halide is 20%, the lamp efficiency is low unless the tube wall load is made larger than 25 W / cm ² , which is not practical.

Next, as shown in FIG. 6, when the tube wall load is greater than 25 W / cm ² , the lamp life characteristics deteriorate, for example, the lamp voltage increases during the lifetime, which is not practical.

Therefore, the tube wall load is set to 22 to 25 W / cm ² , and the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube When a ceramic metal halide lamp is turned on by a ballast for a high-pressure mercury lamp by combining the number of moles of the cesium halide contained in the arc tube with the number of moles of 10% or less with respect to the number of moles. Even so, a lamp having both high lamp power factor and high lamp efficiency can be obtained. This was first discovered by the present inventors.

The life characteristics are described in more detail as follows.
It can be seen from FIG. 6 that the lamp voltage increase value after lighting for 12000 hours increases as the tube wall load increases. When the tube wall load is in the range of 22 to 25 W / cm ² , the lamp voltage increase value is within about 10 V. However, when the tube wall load is greater than 27 W / cm ² , the lamp voltage increase value increases to 20 V or more.

It can be seen from FIG. 7 that the peak voltage after lighting for 12000 hours increases as the tube wall load increases. When the tube wall load is in the range of 22 to 25 W / cm ² , the peak voltage is 0 to ² V, but when the tube wall load is 27 W / cm ² or more, the peak voltage is greater than 5 V.

FIG. 8 shows the improvement effect of the reduction in the lamp voltage rise and the reduction in the peak voltage due to the reduction of the tube wall load described above in terms of the lamp turn-off occurrence rate. Standing consumption incidence of the lamp after 12000 hours lit, that the wall load is is about 20% at 27W / cm ^2, decreasing to 10% or less if the range of 22~25W / cm ² 8 I understand.

As can be seen from FIG. 9, the luminous flux maintenance factor decreases as the tube wall load increases. If the tube wall load is in the range of 22 to 25 W / cm ² , the luminous flux maintenance factor after lighting for 12000 hours is 75 to 85%, but if the tube wall load is 30 W / cm ² , the luminous flux maintenance factor is 60 to 80%. % And the variation becomes larger. That is, if the tube wall load is in the range of 22 to 25 W / cm ² , the luminous flux maintenance factor is high and the variation is small.

  In the above example, the test was performed using a test ballast for a high-pressure mercury lamp. However, commercially available high-pressure mercury lamp ballasts have the same characteristics as this test ballast. Therefore, it is obvious that the same effect as that of the above-described embodiment can be obtained even in a lighting fixture including the metal halide lamp of the above-described embodiment and a ballast for a high-pressure mercury lamp.

And an arc tube containing at least one of dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide, mercury, a rare gas, thallium halide, and sodium halide as an enclosure. In the usage of the provided ceramic metal halide lamp, the arc tube with respect to the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube The number of moles of cesium element in the cesium halide contained in the tube is 10% or less, and by using a ballast for a high-pressure mercury lamp, the tube wall load of the arc tube becomes 22 to 25 W / cm ^2. And ceramic metal halide lamp It is clear that the same result as in the above embodiment can be obtained even when is turned on.

  In the above embodiment, the halide as the light-emitting substance was filled with three kinds of dysprosium halide, thulium halide and holmium halide and thallium halide and sodium halide, but at least dysprosium halide and thulium halide were used. In another experiment, it was confirmed that the effects of the present invention can be obtained by encapsulating one or more of holmium halide, erbium halide, and terbium halide with thallium halide and sodium halide.

Further, in the above embodiment, among dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide, dysprosium halide, thulium halide, and holmium halide are each about 2.0 ×. Although it was used in the arc tube in an amount of 10 ⁻⁶ mol / cm ³ , dysprosium halide, thulium halide, holmium halide, halogen contained in the arc tube even in other mixing amounts and mixing ratios. The same effect can be obtained if the number of moles of cesium element of cesium halide contained in the arc tube is 10% or less with respect to the number of moles of metal element in erbium halide and terbium halide.

  It should be noted that, as described in the specification of the present application, “the arc tube is in proportion to the number of moles of metal elements in dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube. “The number of moles of the cesium element of the cesium halide contained therein is 10% or less” includes the case where no cesium halide is contained.

In addition, the “test ballast for high-pressure mercury lamp” described in the specification of the present application means that defined in Japanese Industrial Standard (JIS) C8110 ₁₉₈₇ . Furthermore, “the ceramic metal halide lamp was turned on by the test ballast for the high-pressure mercury lamp” described in the present specification means that the lamp is turned on according to the test conditions defined in 6.1 of JIS C8110 _1987. To do. Further, Annex Table 1 of JIS C8110 ₁₉₈₇ describes eight types of test ballasts for high-pressure mercury lamps with rated lamp power of 40 W to 1000 W. “The ceramic metal halide lamp was turned on by a test ballast for a high-pressure mercury lamp” described in this specification means that among these ballasts, the rated lamp power of the actual lamp and the JIS C8110 ₁₉₈₇ annex. It means that the lamp with the smallest difference from the “rated lamp power of a suitable lamp” listed in Table 1 is selected and lit. For example, a 360 W metal halide lamp described in an embodiment of the present invention described later is lit using a 400 W ballast.

  Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

These are sectional drawings which show the structure of the arc tube of the ceramic metal halide lamp which is an Example of this invention. These are the schematic block diagrams which show the ceramic metal halide lamp which is one Example of this invention. These are the schematic block diagrams which show the ceramic metal halide lamp which is the other Example of this invention. These are graphs showing the relationship between the tube wall load and the lamp efficiency in the initial characteristics of the example lamp of the present invention and the comparative example lamp. These are graphs showing the relationship between the tube wall load and the lamp power factor in the initial characteristics of the example lamp and the comparative example lamp of the present invention. These are the graphs which show the relationship between the tube wall load and the lamp voltage increase value after lighting for 12000 hours of the example lamp of the present invention and the comparative example lamp. These are the graphs which show the relationship between the tube wall load and the peak voltage after 12000 hours lighting of the Example lamp of this invention and the comparative example lamp. These are graphs showing the relationship between the tube wall load and the lamp extinction occurrence rate after lighting for 12000 hours of the example lamp and the comparative example lamp of the present invention. These are the graphs which show the relationship between the lighting time of the Example lamp | ramp and comparative example lamp | ramp of this invention, and a luminous flux maintenance factor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emission tube 2 Electrode coil 3 Electrode core 4 Electrode 2nd coil 5 Narrow tube part 6 2nd electricity introduction body 7 1st electricity introduction body 9 Sealing material 11 Outer tube 12 Electric conductor and support body 13 Starter 16 Start-up Auxiliary conductor

Claims (2)

At least one of dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide;
mercury,
Noble gas,
In ceramic metal halide lamps equipped with arc tubes containing thallium halide and sodium halide as inclusions,
Cesium halide contained in the arc tube with respect to the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube The number of moles of the cesium element is 10% or less, and the wall load of the arc tube when the ceramic metal halide lamp is turned on by a test ballast for a high-pressure mercury lamp is 22 to 25 W / cm ^2. A ceramic metal halide lamp. At least one of dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide;
mercury,
Noble gas,
In a luminaire comprising a ceramic metal halide lamp having an arc tube containing thallium halide and sodium halide as an enclosure, and a ballast for a high-pressure mercury lamp,
Cesium halide contained in the arc tube with respect to the number of moles of metal elements in the dysprosium halide, thulium halide, holmium halide, erbium halide, and terbium halide contained in the arc tube The number of moles of the cesium element is 10% or less, and the wall load of the arc tube when the ceramic metal halide lamp is turned on by a test ballast for a high-pressure mercury lamp is 22 to 25 W / cm ^2. Lighting equipment characterized by

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