JP2004158218A - Ceramic metal-halide lamp - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ceramic metal-halide lamp that has no trouble such as breakage of the light-emitting tube and deterioration of life property and has a daylight color tone of a long life even if a translucent ceramic light-emitting tube is used. <P>SOLUTION: A rare gas for starting, mercury, terbium halide (TbX<SB>3</SB>), thallium halide (TlX), and cesium halide (CsX) are filled in the light-emitting tube of a ceramic metal halide lamp that is made of a translucent material having electrodes on both ends, and at least one kind of dysprosium halide (DyX<SB>3</SB>), holmium halide (HoX<SB>3</SB>), erbium halide (ErX<SB>3</SB>), and thulium halide (TmX<SB>3</SB>) is filled, and the color temperature is made within the range 5,700-7,100 K. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ceramic metal halide lamp.
[0002]
[Prior art]
Conventionally, quartz glass has been used as the arc tube material of metal halide lamps, but in recent years, ceramic metal halide lamps using translucent ceramics as arc tube materials have been put into practical use. In the case of a metal halide lamp, if the arc tube material is quartz glass, the quartz glass and the metal halide, which is a luminescent material, gradually react during lighting, causing a deterioration in life characteristics. However, when the arc tube material is translucent ceramic, it does not react easily with the metal halide, which is a luminescent material, so the life characteristics are better than the quartz glass arc tube, and the arc tube can be made compact, so the lamp efficiency and color rendering are improved. There is a possibility that a good lamp can be made. For these reasons, in recent years, lamps using translucent ceramics as arc tube materials have been put into practical use.
[0003]
Ceramic metal halide lamps have already been commercialized in white and warm white color temperature series, and are highly evaluated on the market in terms of high efficiency and long life compared to conventional quartz products. Therefore, the market demands lamps of daytime white and daylight color temperature series. In response to requests from the market, we studied daylight lamps. When the conventional arc tube is of a quartz glass type, a typical combination of encapsulating substances that emit daylight light is a Dy-Nd-Cs-I combination (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 4-032155
[Problems to be solved by the invention]
In the preliminary test, when the enclosure was actually enclosed in a ceramic arc tube and turned on as a lamp, the lamp could be lit without any problems in vertical lighting, but the arc tube was damaged with high probability in horizontal lighting. This is because the discharge arc tends to bend upward when it is lit horizontally, and it is considered that the enclosure system with a high discharge arc temperature was damaged due to a rapid temperature rise at the top of the arc tube.
[0006]
Actually, the damage occurred in about 2 minutes after the lamp was turned on, and it is just the time when Dy and Nd start to emit light. When this inclusion system, particularly Nd, is added, the arc temperature tends to increase, and it is considered that the addition of Nd has a great influence on the breakage of the arc tube.
[0007]
As a countermeasure, substances that reduce the arc temperature (Tl, In) were added to investigate the effect. As a result, in the Dy-Nd-Cs-Tl-In-I-based enclosure to which Tl and In were added, the lamp was not damaged during horizontal lighting, but the upper part of the arc tube became cloudy due to the heat of the arc, The luminous flux maintenance factor was not good.
[0008]
Therefore, we examined other inclusion systems that produce daylight shades. SUMMARY OF THE INVENTION An object of the present invention is to provide a ceramic metal halide lamp having a long-life color of daylight without causing defects such as breakage of the arc tube and deterioration of life characteristics even when a translucent ceramic arc tube is used.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, a ceramic metal halide lamp according to the present invention includes a starting rare gas, mercury, terbium halide (TbX ₃ ), and thallium halide inside an arc tube made of a translucent material having electrodes at both ends. (TLX) and cesium halide (CsX) is sealed, and halogenated Jisuburoshiumu _(dyx 3), halogenated holmium _(Hox 3), erbium halides _(ERX 3), at least one halogenated thulium (TMX ₃₎ And the color temperature is in the range of 5700-7100K.
[0010]
According to the present invention, even when the lamp is lit horizontally, bursting of the arc tube can be suppressed, and a long-life daylight color ceramic metal halide lamp with a color temperature of 5700 to 7100K can be obtained.
[0011]
In addition, the amount of the encapsulated substance is expressed in terms of the number of moles of Tb, Dy, Ho, Er, and Tm, where A is the molar ratio of Tb to A is 0.15 to 0.25, and It is preferable that the molar ratio of Tl is 0.15 to 0.4 and the molar ratio of Cs to A is 0.5 to 0.8. This is because it is possible to provide a long-life daytime ceramic metal halide lamp having an excellent luminous flux maintenance factor.
[0012]
The halide is preferably iodide or bromide.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail by embodiments of the present invention.
FIG. 1 is a schematic sectional view of the arc tube. An arc tube 10 made of a translucent ceramic tube (alumina) is composed of a main tube 11 at the center and thin tubes 12 attached to both ends thereof. The small-diameter portion 13 and the thin tube 12 are hermetically joined via an alumina disk 14, and the inside of the thin tube 12 at the outer end portion of the arc tube is made of a first metal connected to the electrode core 15. The electrical introduction body 16, the electrical introduction body 17 made of the second metal, and the ceramic sleeve 18 are hermetically fixed by a sealing glass 19. A first coil 20 and a second coil 21 are wound around the electrode core. Rare gas and mercury for starting the arc _{tube, DyI 3, TbI 3, CsI} , the TlI is sealed. The arc tube is built in a hard glass outer sphere by a support member (not shown).
[0014]
The selection of inclusions is a Dy-Tb-Tl-Cs-I system centered on Tb, which emits light at a high color temperature of about 10,000 K, and Dy, which gives high color rendering properties, in order to produce a daylight color shade. Consists of inclusions.
[0015]
First, we put the shade of daylight, and high color rendering, in order to investigate the proportion of inclusions of a high efficiency, the sum of DyI ₃ and TBI ₃ is a rare earth metal halide and A (unit mol), TBI ₃ / A = 0 to 0.5 (mol ratio), TlI / A = 0 to 1.0 (mol ratio), CsI / A = 0.3 to 1.0 (mol ratio) It was. The test was performed with a lamp having a rated power of 400 W using an arc tube having an inner diameter of 18.5 mm and an arc length of 27 mm. Moreover, the said enclosure was 100 micromol in total.
[0016]
It has been known that CsI has an effect of stabilizing the discharge arc. First, when the range of CsI / A where the discharge arc is stabilized was investigated, when CsI / A <0.5, the fluctuation and curvature of the arc were observed. It was found that there is a high probability of occurrence.
[0017]
Next, TbI ₃ / A was changed at CsI / A = 0.5, and the range of daylight shades was investigated. TlI / A at that time was set to 0.15. The result is shown in FIG. It can be seen from FIG. 2 that the daylight color is TbI ₃ /A=0.15 to 0.4.
[0018]
A factor that determines the upper limit of CsI / A is lamp efficiency. If the efficiency is not higher than that of a daylight lamp using a quartz arc tube that has already been commercialized, there is no advantage of using a ceramic arc tube, and an efficiency of 80 lm / W or more is considered necessary. The characteristics were investigated by changing CsI / A in the range of TbI ₃ /A=0.15 to 0.4. TlI / A at that time was set to 0.15. The results are shown in FIGS. From FIG. 3 and FIG. 4, the condition of daylight color temperature and efficiency of 80 lm / W or more satisfies TbI ₃ /A=0.15 to 0.25 and CsI / A = 0.5 to 0.8. It turns out to be desirable.
[0019]
Next, when TlI / A was changed from 0 to 1.0 in the range of TbI ₃ /A=0.15 to 0.25 and CsI / A = 0.5 to 0.8, the higher TlI / A was, Lamp efficiency increased. In addition, although there was no significant change in the color temperature, the color becomes more green as TlI / A becomes higher. On the contrary, when TlI / A = 0, it is felt reddish, and it was found that the range of TlI / A = 0.15 to 0.4 is good for obtaining a good daylight color shade.
[0020]
Note that instead of _{DyI 3 HoI 3, ErI 3,} TmI similar results using ₃ simple substance or composite was obtained. Further, similar results were obtained when bromide or a mixture of iodide and bromide was used instead of iodide.
[0021]
From the above test results, it can be seen that the ratio of inclusions should be within the following range.
Total amount of TbX ₃ , DyX ₃ , HoX ₃ , ErX ₃ , TmX ₃ : A
TbX ₃ / A = 0.15~0.25 (mol ratio)
TlX / A = 0.15-0.4 (mol ratio)
CsX / A = 0.5-0.8 (mol ratio)
In addition, when a lamp produced within the above range was subjected to a life test with horizontal and vertical lighting, there were no defects such as breakage or deterioration of life characteristics, and good characteristics were obtained.
[0022]
The life test results are shown in FIG. This lifetime characteristic is a lamp with a long lifetime because the luminous flux maintenance factor is greatly improved as compared with the case where a quartz arc tube is used.
[0023]
【The invention's effect】
As described above, according to the present invention, there is provided a ceramic metal halide lamp having a long-life color of daylight without causing defects such as breakage of the light-emitting tube and deterioration of life characteristics even when a translucent ceramic light-emitting tube is used. be able to.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view of a ceramic arc tube.
FIG. 2 is a graph showing a change in color temperature when TbI ₃ / A is changed.
FIG. 3 is a diagram showing a change in color temperature when CsI / A changes.
FIG. 4 is a diagram showing a change in efficiency when CsI / A changes.
FIG. 5 is a diagram showing a life test result.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Light emission tube 11 Main tube 12 Narrow tube 14 Disc 15 Electrode core 16 Electric introduction body 17 Electric introduction body 18 Ceramic sleep 19 Sealing glass 20 1st coil 21 2nd coil

Claims (1)

A starting rare gas, mercury, terbium halide (TbX ₃ ), thallium halide (TlX), and cesium halide (CsX) are enclosed in an arc tube made of a translucent material having electrodes at both ends, and halogenated Jisuburoshiumu _(dyx 3), halogenated holmium _(Hox 3), erbium halides _(ERX 3), at least one halogenated thulium (TMX ₃₎ is sealed, the color temperature is within the range of 5700~7100K This is a ceramic metal halide lamp.

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