JPH06338285A - Metal halide lamp, lighting apparatus, and luminaire - Google Patents

Abstract

PURPOSE:To manufacture a metal halide lamp with excellent color rendering properties and a long life by respectively specifying the mole ratio of the sealed quantity of excessive halogens and the sealed quantity of rare earth metals in a light emitting tubular bulb whose bulb load is standardized and the mole ratio of bromine and iodine. CONSTITUTION:Regarding metal halide in a light emitting tubular bulb of which rare earth metals and halogens in excessive quantity more than the chemical equivalent to the rare earth metals are sealed and whose bulb load is 40-58W/cm<2>, the mole ratio of the sealed quantity H of the excessive halogens and the sealed quantity RM of the rare earth metals is set to be 0.84<H/RE<3.10 and at the same time the mole ratio of excessive bromine (Br) and iodine (I) at the time of sealing is set to be 1<Br/I<6.7. Consequently, a metal halide lamp with good lumen maintenance factor and scarce correlated hue change is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal halide lamp in which a metal halide is enclosed in an arc tube bulb.

[0002]

2. Description of the Related Art Generally, a metal halide lamp is a lamp in which a metal halide is enclosed together with a rare gas for starting and mercury in an arc tube bulb, and light emission peculiar to those metals is utilized to improve luminous efficiency and color rendering. It is widely used for general lighting.

Other than general lighting such as televisions, movies,
A metal halide lamp used for images such as photographs needs to be a point light source for easy light control, and a light emitting portion of the lamp, that is, a short arc type with a short distance between electrodes is desirable.

However, a suitable additive composition ratio of a metal halide lamp for general lighting having a long distance between electrodes and a low tube wall load, such as a ratio of metal to halogen, is used for general lighting having a short electrode distance and a high tube wall load. When applied to metal halide lamps, problems such as instability of the arc and significant reduction of luminous flux during its life may occur.

Therefore, such a short arc metal halide lamp is filled with a rare earth metal, and the area inside the discharge vessel is very small with respect to the lamp input (tube wall load 30 W /
cm ² or more), a continuous spectrum is obtained over the entire visible light range and high color rendering properties are realized.

In a lamp having a high load on the tube wall, the arc tube bulb becomes high in temperature and a reaction between rare earth metal and quartz occurs to devitrify the arc tube bulb, or due to an improper halogen cycle, the arc tube bulb. There is a problem that blackening occurs due to adhesion of tungsten to the inner wall, and in order to prevent this, an excess of halogen with respect to the chemical equivalent of the enclosed rare earth metal is enclosed.

[0007]

However, in a lamp having a rated life of 1000 hours or more, the emission characteristics of the rare earth metal encapsulated as a halide are different depending on the type of halogen, that is, the type of Br (bromine) and I (iodine). Therefore, since the halogen of the rare earth halide and the excess halogen are switched according to the lighting time, the color characteristics change. Further, there is a problem that the replacement of the halogen causes a change in the amount of excess halogen, which causes the arc tube bulb to devitrify and deteriorate due to blackening.

The present invention has been made in view of the above problems,
An object of the present invention is to provide a metal halide lamp having excellent color rendering properties and life characteristics, and a lighting fixture equipped with this lamp.

[0009]

A metal halide lamp according to claim 1 of the present invention has a tube wall load formed by enclosing a rare earth metal and an excess halogen exceeding the chemical equivalent of the rare earth metal in an arc tube bulb. In a metal halide lamp of 40 to 58 W / cm ² , the molar ratio between the above-mentioned excess halogen filling amount H and rare-earth metal filling amount RM is 0.84 <.
There is a relationship of H / RM <3.10 and the molar ratio of excess halogen Br (bromine) and I (iodine) at the time of encapsulation is 1 <Br /
It is characterized in that I <6.7.

In the metal halide lamp according to the second aspect of the present invention, the tube wall load is 40 to 58 W / cm ² in which the rare earth metal and the excess halogen exceeding the chemical equivalent of the rare earth metal are enclosed in the arc tube bulb. in the metal halide lamp, the excess halogen enclosed amount H (mol) and the tube wall load W (W / cm ²⁾ the relationship between the 1.02 × 10 ^{- 3}
<H · W <5.4 × 10 ⁻³ , and the molar ratio of excess halogen Br (bromine) and I (iodine) at the time of filling is 1 <
It is characterized in that Br / I <6.7. A lighting device according to a third aspect of the present invention includes a lighting circuit and the metal halide lamp according to the first or second aspect, which is connected to an output side of the lighting circuit.

According to a fourth aspect of the present invention, there is provided a lighting fixture, wherein the metal halide lamp according to the first or second aspect, a reflecting mirror housing the lamp, and a light-transmitting member provided in front of the reflecting mirror. It is characterized by having a body.

[0012]

With a proper tube wall load and an excessive amount of halogen, a good halogen cycle can be obtained, and stable light emission characteristics can be obtained if the life is about 2000 to 3000 hours.

[0013]

EXAMPLE First, in an experiment conducted by the present inventors, a high pipe wall load (4
When the lamp with 0 to 58 W / cm ² ) was not filled with excess halogen, the arc tube bulb was rapidly blackened by lighting, and the luminous flux maintenance factor was 70% or less after 500 hours of lighting. Moreover, if only Br (bromine) is enclosed as excess halogen, the halogen cycle of Br (bromine) causes W
Low temperature part of electrode made of (tungsten) (1900K
Since W (tungsten) sublimated from the following) to the high temperature portion (2000 K or more) is carried, blackening of the arc tube bulb can be prevented. However, since W (tungsten) was transported to the high temperature part (tip of the electrode) of the electrode, the electrode shaft became thin and was broken.

In order to prevent this, it is necessary to encapsulate excess I (iodine) at the same time and bring the cycle of only Br (bromine) closer to the cycle of I (iodine) to eliminate electrode breakage. At this time, if the amount of excess I (iodine) is too large, the halogen cycle becomes too much on the I (iodine) side, and the arc tube is blackened again in a short time and the luminous flux maintenance factor is rapidly reduced. As described above, it has been found that, in a lamp with a high tube wall load, the amount of excess halogen Br (bromine) and I (iodine) enclosed greatly affects the life characteristics.

Therefore, the present inventors manufactured the metal halide lamp L shown in FIG. In FIG. 1, 1 is an arc tube bulb made of quartz glass having an elliptical central portion, 2 and 2 are electrodes facing each other in the elliptical portion of the bulb 1, and 3 are formed at both ends of the bulb 1. At the sealing portion, the molybdenum foil 4 connected to the electrode 2 is hermetically sealed in each of the sealing portions 3 and 3. Further, 5 is a ceramic base attached to the end of the sealing portion 3, 6 is a lead wire extending from the base 5, 7 is a terminal connected to the tip of the lead wire 6, 8
Is an exhaust pipe, and 7 is a heat insulating film applied to the outer surface of the oval portion of the valve 1.

Specific dimensions of each part of the lamp L are as follows: the distance between the electrodes 2 and 2 is about 33 mm, the inner diameter of the center of the elliptical part of the bulb 1 is about 36 mm, and the maximum internal length in the axial direction of the bulb 1 is about 60 mm. The tube wall load is 45 W / cm ² .
Argon gas of about 100 torr is used as an inert gas for starting assistance in the bulb 1, and the above-mentioned DyBr ₃ (dysprosium bromide) -HoBr ₃ (holmium bromide) -TmBr _{3 is used} as a light emitting metal of a rare earth halide. (Thulium bromide) -CsI (cesium iodide) in a molar ratio of 1:
About 20 mg and HgI _{2 in} the ratio 1: 1.3: 3.3
Approximately 11 mg of (mercury iodide) and HgBr ₂ (mercury bromide)
It is enclosed. And Br (bromine) in this valve 1
The chemical equivalents of and I (iodine) are enclosed in a larger amount than the chemical equivalent of the above-mentioned rare earth metal.

The lamp L having the above structure is used for the lamp current 2
When turned on at 0A / 2Kw, luminous efficiency is 85Lm /
White light with W, an average color rendering index Ra93, and a color temperature of 6000K was obtained. This excellent luminous efficiency and color rendering are Dy
(Dysprosium), Ho (holmium) and Tm
This is due to the continuous spectrum spread over the entire visible part of (thulium). Further, the arc was thick and stable due to the effect of Cs (cesium), and the arc did not fluctuate.

This is Dy (dysprosium), Ho
Br for (holmium) and Tm (thulium)
Since the amounts of (bromine) and I (iodine) are proper, that is, there is a proper amount of excess Br (bromine) and I (iodine), the halogen consumption is moderate and the electrode material is sputtered with tungsten due to an appropriate halogen cycle. Arc tube bulb 1 by
This is because the blackening of the inner wall is suppressed.

The metal halide lamp L as described above is used by being attached to the device D as shown in FIGS. 2 to 3, reference numeral 10 denotes a reflecting mirror, which is composed of a rear reflector 11 and a front reflector 12. The rear reflector 11 is formed into a substantially bowl shape by aluminum die casting, casting of a metal shape, sand shape or the like, and a reflecting surface 13 is formed on the inner surface thereof. Further, a pair of box-shaped connection boxes 14 are bulged and formed at two opposite positions of the rear reflector 11. The partition wall 1 is placed in the wiring box 14.
5 is formed, a lamp mounting chamber 16 is formed on the front side of the partition wall 15, and four leg portions 17 each having a screw hole (not shown) are formed in front of the lamp mounting chamber 16 so as to swell. As shown in FIG. 3, screws 1 are attached to these legs 17.
A lamp support plate 19 is attached at 8, and the support plate 1
The base portion 5 is attached to the lamp L by a spacer 20 attached to the lamp 9 so as to be substantially horizontal.

Further, the ring-shaped terminal 7 at the tip of the lead wire 6 extending from the base 5 of the lamp L is led out to the terminal mounting chamber 22 formed on the opposite surface via the insertion hole 21 formed in the partition wall 15. Has been done. A terminal plate (not shown) is attached to the attachment portion 23 in the terminal attachment chamber 22 and is connected to the ring-shaped terminal 7 and the power supply lead wire (not shown).

In front of the rear reflector 11, there is provided a cylindrical front reflector 12 formed in the same manner as described above. The front reflector 12 is provided on the rear side of the rear reflector 11.
It is shaped like a bowl that is continuous with, and has a reflective surface 2 on its inner surface.
4 are formed. Further, on the front surface side of the reflecting surface 24, the non-reflecting surface 2 is formed in a substantially cylindrical shape in which the inner surface is painted black and the maximum diameter portion of the reflecting surface 24 is extended as it is.
5 is formed. A front glass body 26 as a translucent body made of tempered glass having excellent heat resistance and impact resistance is watertightly attached to the frontmost surface of the front reflector 12.

The front reflector 12 has a pair of support members 27 projectingly formed at two positions on the rear side thereof.
A rear reflector mounting portion 28 for mounting the rear reflector 11 is formed on the inner surface of the housing, and an equipment mounting portion 29 for mounting the body D of the housing is formed between the support portions 27, 27. Further, reference numeral 30 is a radiation fin for cooling the equipment, which is integrally formed on the rear surface side of the rear reflector 11 substantially in parallel with a gap.

The circuit parts for lighting the lamp L may be housed in the device D or may be installed separately from the device D.

Therefore, the present inventors used the bulb 1 and the electrode 2 having the same size as the above and the same luminescent metal as the above,
HgI ₂ (mercury iodide) and H sealed in the arc tube bulb 1
The lamp was changed to 10 for each lamp with various amounts of gBr ₂ (mercury bromide).
This was manufactured, and its characteristics (flux maintenance ratio, correlated color temperature change, etc.) were investigated.

Then, these various metal halide lamps L were used at the same lamp current of about 20 A · 2 Kw for 20 times.
It turned on for 00 hours.

The contents and test results are shown in Table 1 and FIGS.

[0027]

[Table 1] FIG. 4 shows the relationship between Br (bromine) / I (iodine) (molar ratio%) of these lamps L and the luminous flux maintenance rate (ratio% to the luminous flux at the initial lighting) after 1000 hours of lighting, and the horizontal axis represents Br.
/ I (molar ratio%), and the vertical axis shows the luminous flux maintenance ratio%. Generally, the metal halide lamp L has a luminous flux maintenance rate of 70% or less and can be said to have a life.
When / I (iodine) (molar ratio%) is 1 or less, it can be said that the lamp life as seen from the luminous flux maintenance factor is fulfilled.

In addition, FIG. 5 similarly shows the Br of these lamps L.
(Bromine) / I (iodine) (molar ratio%) is shown in comparison with the change in correlated color temperature after 2000 hours of lighting, and the horizontal axis represents Br / I.
(Mole ratio%), and the vertical axis indicates the correlated color temperature change K. Lamp L filled with rare earth metal halide
The correlated color temperature tends to decrease with the progress of lighting.
This is because the larger the amount of free I (iodine) is, the larger the change is. Therefore, the change of Br (bromine) in the halogenated rare earth and I (iodine) in the free halogen shifts the emission of the rare earth metal halide to the red side. It is thought that it will occur. Considering that the correlated color temperature at the initial stage of lighting is about 6000K, and that a small color temperature difference in this vicinity is hard to be visually recognized, assuming that the difference of 800K or more visually perceived as the lamp life is Br (bromine). ) / I (iodine) (molar ratio%) is 1 or more, it can be said that the encapsulation ratio is appropriate.

Further, FIG. 6 similarly shows Br of these lamps L.
(Bromine) / I (iodine) (molar ratio%) is shown in comparison with the remaining rate% of the lamp L that can be lit for 2000 hours, with the horizontal axis representing Br / I (% molar ratio) and the vertical axis representing the remaining ratio. Indicates the remaining rate%. In consideration of the fact that the electrode is corroded by halogen and becomes smaller in diameter and breaks as described above, it is necessary to limit the amount of Br (bromine), which has a stronger corrosiveness than I (iodine), and the residual rate is 50% or more. If it passes, it is considered appropriate that Br (bromine) / I (iodine) (molar ratio%) is 6.7 or less.

Further, a metal halide lamp (a lamp having a particularly high tube wall load) containing a rare earth metal has a problem of devitrification of the arc tube due to a reaction between quartz (the inner surface of the arc tube) and the rare earth.

Due to this white turbidity, the radiated light from the arc tube has an unclear image of the light source (arc) with respect to the reflecting mirror, and when used in a projector (especially in a short arc type with a small light source (arc)). ) The light distribution characteristics, especially the central luminous intensity, are significantly impaired. The reaction between quartz and rare earth tends to decrease by encapsulating excess halogen, and the relationship between the amount of encapsulated rare earth and the amount of excess halogen is important. Also,
Since the reactivity greatly depends on the tube wall temperature, the relationship with the tube wall load is also important.

A lamp in which the amount of rare earth is fixed and the amount of excess halogen is changed is incorporated into the above-mentioned floodlight, and it is used at 0 hours and 20 hours.
The central luminous intensity (cd) after lighting for 00 hours was measured. The measurement result is shown in FIG. Fig. 7 shows the amount R of rare earth metal filled on the horizontal axis.
Excess halogen inclusion amount with respect to M (mol) ((Br + I)
= H), (Br + I) or H / RM (atomic ratio), and the horizontal axis indicates the central luminous intensity ratio (vs. 0 hours%). As shown in the figure, the smaller the amount of halogen enclosed, the lower the central luminous intensity. If the reduction rate of the central luminous intensity after lighting for 2000 hours is 40% or less with respect to the initial lighting (0 hour%), it is necessary to set (Br + I) or H / RM to 0.84 or more. By the way, (Br + I) or H / RM ≧ 3.1
0 data is not entered, but this is lit 200
This is because the lamp became unlit due to electrode deformation within 0 hours.

Considering the results of Table 1 and FIGS. 4 to 7, the relationship between the amount RM (mol) of the rare earth metal and the amount (Br + I) or H (mol) of the excess halogen is ((Br + I)). or H / RM) (atomic ratio) is 0.84
The range of up to 3.10.

Further, since the correlated color temperature change is caused by the exchange of Br (bromine) of the halogenated rare earth metal and I (iodine) of the excess halogen, the above Br (bromine) / I (iodine) is the rare earth metal. It can be said that it holds in the range of excess halogen content.

From the viewpoint of preventing blackening of the arc tube bulb, the relationship between the amount of excess halogen and the arc tube temperature is important.
This is the relationship between the excess halogen amount H and the tube wall load W (H · W)
Therefore, the range is 1.02 × 10 ^{−3 to} 5.40 × 10 ⁻³ .

The present invention is not limited to the above embodiment. For example, the rare earth metal halides are not limited to those described in the above examples, and similar results were obtained with other rare earth metals.

Further, in the above embodiment, the same input lamp was tested with one kind of arc tube bulb, but the same tendency is observed even when the bulb internal volume is changed by changing the bulb inner diameter, the interelectrode distance and the like. Was obtained.

Further, according to the present invention, a remarkable effect can be obtained in the lamp L of 40 to 58 W / cm 2 in which the inner area of the arc tube bulb is made smaller than the lamp input, that is, the tube wall load is high.

Further, the reflecting mirror of the lighting equipment of the present invention is not limited to the structure described in the embodiment, and may be a single bowl-shaped reflecting mirror, and the front shape is not limited to a circular shape but a square shape such as a square shape. Does not matter. Further, the translucent body on the front surface is not limited to a simple plate-shaped one, but may be a lens-shaped one.

[0040]

As described above in detail, according to the present invention, it is possible to provide a metal halide lamp and a lighting device which are excellent in color rendering properties and luminous flux maintenance factor, have little change in correlated color temperature, and have improved life characteristics. .

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a metal halide lamp of the present invention.

FIG. 2 is a partial cross-sectional plan view showing a state where the metal halide lamp of FIG. 1 is housed in a lighting fixture.

FIG. 3 is a front view of a rear reflector with a lamp attached in the lighting fixture of FIG.

FIG. 4 is a comparison diagram showing the relationship between the molar ratio% of Br (bromine) to I (iodine) and the luminous flux maintenance factor.

FIG. 5 is a comparison diagram showing the relationship between the molar ratio% of Br (bromine) to I (iodine) and the change in correlated color temperature.

FIG. 6 is a comparison diagram showing the relationship between the molar ratio% of Br (bromine) to I (iodine) and the remaining rate of the lamp L that can be lit.

FIG. 7 is a comparison diagram showing the relationship between the atomic ratio of the amount of excess halogen enclosed ((Br + I) = H) to the amount of rare earth metal enclosed RM (mol) and the central luminous intensity ratio (against 0 hour%).

[Explanation of symbols]

 L: Metal halide lamp 1: Arc tube bulb 2: Electrode 3: Sealing part 10: Reflecting mirror 26: Translucent body (front glass body)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshio Hikita 1-4-2-4 Mita, Minato-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (4)

[Claims] 1. A metal halide lamp having a tube wall load of 40 to 58 W / cm ² in which a rare earth metal and an excess halogen exceeding the chemical equivalent of the rare earth metal are enclosed in an arc tube bulb. The molar ratio between the amount H and the amount RM of the rare earth metal is 0.84 <H / RM <
There is a relationship of 3.10 and excess halogen Br at the time of filling
The molar ratio of (bromine) to I (iodine) is 1 <Br / I <6.7.
Is a metal halide lamp. ^2. A metal halide lamp having a tube wall load of 40 to 58 W / cm ² in which a rare earth metal and an excess halogen exceeding the chemical equivalent of the rare earth metal are enclosed in an arc tube bulb. Amount H (mol)
And the tube wall load W (W / cm ² ) are 1.02 × 10
^-3 <H · W <5.4 × 10 ^-3 , and the molar ratio of excess halogen Br (bromine) and I (iodine) at the time of encapsulation is 1 <Br / I <6.7. Is a metal halide lamp. 3. A lighting device comprising: a lighting circuit; and the metal halide lamp according to claim 1, which is connected to an output side of the lighting circuit. 4. A metal halide lamp according to claim 1 or 2, a reflecting mirror accommodating the lamp, and a translucent body provided in front of the reflecting mirror. Lighting equipment.