JPH11102663A - Metallic vapor discharge lamp and floodlight device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metallic vapor discharge lamp of an undersized short arc type which reduces troubles caused by mercury enclosing, and a floodlight device loaded with the discharge lamp. SOLUTION: A metallic vapor discharge lamp L1 provided with a light transmissive airtight container 2 with an internal capacity <=1 cc, discharge electrodes 5a, 5b oppositely arranged at an discharge interval <=5 mm within the airtight container 2, metal halide which is enclosed within the airtight container 2 and includes at least one kind selected among thallium, indium and tin and does not substantially include mercury, and rare gas, and a floodlight device loaded with the discharge lamp L1 are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a short arc type metal vapor discharge lamp in which a metal halide substantially free of mercury is sealed, and a floodlight equipped with the discharge lamp.

[0002]

2. Description of the Related Art In order to further improve the efficiency and color rendering of a high-pressure mercury lamp, there is a metal vapor discharge lamp called a metal halide lamp in which a metal halide is added in addition to mercury as a luminescent material. This metal vapor discharge lamp is composed of a light-transmitting airtight container made of quartz glass or ceramics, and a discharge medium made of a metal halide such as mercury, sodium iodide-scandium iodide and a rare gas. And is widely used as a lamp having high efficiency and high color rendering performance for indoor and outdoor lighting.

[0003] This kind of metal vapor discharge lamp is filled with mercury in order to maintain the electrical characteristics. When the lamp is lit, the pressure of this mercury decreases as the size of the arc tube (translucent airtight container) decreases. In the case of a small short arc type metal vapor discharge lamp having an arc tube (translucent airtight container) having an inner volume of 1 cc or less, it is necessary to increase
The pressure is higher than 0 atm.

[0004] The short arc type metal vapor discharge lamp has the following problems because it contains mercury. One is that the mercury is sealed in the arc tube (translucent airtight container), and when the lamp is discarded due to its end of life, it takes time to process and there is a concern that it may adversely affect the environment. .

[0005] Secondly, if the pressure inside the arc tube (translucent airtight container) during lamp operation is higher than 20 atm and the lamp is turned off for any reason, For example, a high-voltage and high-energy pulse generation circuit is required to restart the lamp instantaneously, which complicates the lighting circuit and increases the cost of increasing the insulation resistance of lamps, circuit devices, and appliances. I have.

Third, as described above, since the pressure in the arc tube (translucent airtight container) during lamp operation is a high pressure of 20 atm or more, processing distortion during the formation of the airtight container is reduced. The stress caused by the thermal shock caused by the flashing of the lamp increases, and the hermetic container ruptures, reflecting not only the arc tube (translucent airtight container), but also the equipment that has the arc tube (translucent airtight container). Mirrors and light control bodies may be damaged.

[0007]

Problems to be solved in a small short arc type metal vapor discharge lamp are the environment when the lamp is discarded, the instantaneous restart of the lamp, and the problem of the arc tube (translucent airtight container). It is a point of rupture.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small-sized short arc type metal vapor discharge lamp in which the adverse effects of mercury filling are reduced.

[0009]

According to a first aspect of the present invention, there is provided a metal vapor discharge lamp having a translucent airtight container having an internal volume of 1 cc or less and a discharge space of 5 mm or less in the airtight container. And a discharge medium substantially free of mercury containing a metal halide containing at least one selected from thallium, indium and tin and a rare gas sealed in an airtight container. It is characterized by having.

This discharge lamp is provided with discharge electrodes opposed to each other with a discharge interval of 5 mm or less in a translucent hermetic container having an internal volume of 1 cc or less. It is a small short-arc lamp that changes its electrical characteristics to mercury when it is turned on and maintains it with thallium, indium or tin. Radiate. At the time of startup, gaseous xenon immediately generates a discharge to emit light, and supplements a period until a light emitting substance such as thallium evaporates and emits light. Since thallium and the like are sealed as a halide with iodine and the like, they have a higher vapor pressure than thallium metal and emit light of a predetermined wavelength following xenon.

In addition, since no mercury whose luminous energy changes greatly depending on the input is not sealed, there is no mercury luminescence, and since the light is emitted from a metal halide and a rare gas, the change in luminescent color is reduced even if the input is changed. Can be suppressed.

The above-mentioned halide to be enclosed may be mainly composed of at least one selected from tantalum, indium and tin, and may contain other metals.
The halogen may be bromine, chlorine or fluorine in addition to iodine, and a mixture of these substances or a mixture of these substances as a main component with other substances has the same effect as described above. The rare gas to be filled may be argon or krypton in addition to xenon, and a mixture of these gases or a mixture of these gases with another inert gas or nitrogen may have the same effect as described above. To play.

Further, the reason that the present invention does not substantially contain mercury in the above description is that mercury is not enclosed in the arc tube of the discharge lamp according to the present invention in principle, but the mercury is actually contained due to fouling of manufacturing equipment. It is assumed that an amount of mercury (about 0.05 mg / cc or less) that does not contribute to the light emission characteristics of the compound will enter, and this amount is included in the category substantially free of mercury of the present invention. Is what it means. As described above, the lamp does not have mercury or the amount of mercury is small even if it is present, so that this lamp can be easily disposed of after the end of its life.

This lamp can be used for general lighting indoors and outdoors, for store lighting, for backlighting projectors, and for headlights of automobiles and railway vehicles.

In the metal vapor discharge lamp according to the second aspect of the present invention, the amount of metal halide containing at least one selected from thallium, indium and tin is 5 to 5.
It is characterized by 200 mg / cc.

The amount of metal halide to be enclosed is 5 mg / cc.
If it is less than the above, it is difficult to obtain a lamp voltage of 30 V or more,
The current must be increased, which leads to an increase in the cost of the lighting circuit member. On the other hand, if it exceeds 100 mg / cc, the discharge becomes unstable and the arc bends and flickers. Unevaporated halide accumulates at one end of the arc tube when the lamp is vertically pointed, and the light emission color is remarkably above and below the arc tube. May change.

The metal vapor discharge lamp according to a third aspect of the present invention is characterized in that the rare gas is at least one selected from the group consisting of argon, krypton, and xenon, and is sealed at 1 atm or more.

The rare gas charging pressure is 1 atm (normal temperature = 25 ° C.)
When the pressure is less than the above range, there is a problem that discharge is hardly generated at the time of starting and instantaneous discharging is difficult and the starting characteristics are deteriorated. The sealing pressure is preferably about 1 to 5 atm (normal temperature).

On the other hand, if the sealing pressure is 5 atm (normal temperature) or more, the pressure increases 5 to 7 times when the lamp is turned on. If the airtight container is damaged or distorted, cracks are generated from this portion and the container is ruptured. It will be easier.

According to a fourth aspect of the present invention, there is provided a light emitting device comprising: a reflecting mirror; a metal vapor discharge lamp according to any one of the first to third aspects disposed in the reflecting mirror; And a lighting circuit connected thereto.

Since a metal vapor discharge lamp having the functions described in the above-mentioned claims 1 to 3 is mounted, the above-mentioned claims 1 to 3 are mounted.
In addition to the effect described in 3, the current capacity of the circuit with respect to restart can be set low, and at the same time, damage to the reflector and the cover due to the burst of the arc tube can be prevented.

The light projecting device can be used for general lighting indoors and outdoors, for store lighting, for backlighting projectors, and for headlights of automobiles and railway vehicles.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a short arc type metal vapor discharge lamp L1 according to the present invention. In the figure, reference numeral 1 denotes an arc tube, 2 denotes a translucent airtight container made of quartz glass, and 3a and 3b denote sealing portions formed at both ends of the airtight container 2, 4a and 4b denote sealing portions 3a and 3a. 3b, a metal foil made of molybdenum Mo, etc.,
Reference numerals a and 5b denote a pair of discharge electrodes made of tungsten W or tungsten W containing thorium Th, which are connected to the metal foils 4a and 4b and whose leading ends are opposed to each other with a predetermined discharge interval, and 6a and 6b are metal. The outer conductor is connected to the foils 4a and 4b and is led out of the airtight container 2 to the outside.

A light emitting tube 1 is formed by enclosing a halide such as tantalum iodide TlI and a rare gas such as xenon as a luminescent substance in the hermetic container 1. In the discharge lamp L1 having such a configuration, the electric characteristics at the time of lighting are changed to mercury and maintained by thallium Tl, and the thallium Tl emits light to exhibit predetermined characteristics. At the time of starting, the gaseous xenon Xe immediately generates a discharge and emits light, and supplements the time until the thallium Tl evaporates and emits light. Thallium Tl has a higher vapor pressure than thallium metal because it is enclosed as a halide with iodine I, and emits light of a predetermined wavelength following xenon Xe. In addition, mercury whose emission energy changes greatly by input is not enclosed, so there is no mercury emission, and since it is a metal halide and rare gas emission, it is possible to keep the change in emission color low even if the input is changed. it can.

The light-emitting substance comprising a halide to be encapsulated in the present invention is not limited to tantalum Tl but may be indium In or tin Sn, and is mainly composed of at least one selected from these, and contains other metals. May be used.

The halogen is iodine I, bromine B
r, chlorine Cl or fluorine F may be used, and even if these substances are mixed or these substances are mainly mixed with other substances, the same operation and effect as described above can be obtained.

The rare gas to be filled is xenon X
Not only e but also argon Ar or krypton Kr may be used. Even if these gases are mixed or these gases are mainly mixed with other inert gas or nitrogen, the same operation and effect as described above can be obtained.

Next, a specific embodiment will be described.

The translucent airtight container 2 (made of quartz glass) has a total length of about 40 mm, a substantially elliptical portion in the center portion having a major axis of about 7 mm × a minor axis of about 6 mm (wall thickness of about 1 mm) and an internal volume of about 0 mm. .
The discharge electrodes 5a and 5b had a discharge interval of about 4.2 mm. Further, xenon Xe is charged at about 1 atm (normal temperature) as a sealing gas, and thallium TlI, InI, Sn is used as a luminescent metal (metal halide).
Three types of discharge lamps according to the present invention, each containing about 0.5 mg of I ₂ , and about 0.7 mg of mercury in a conventional configuration (the configuration other than the luminescent material is the same as above) for comparison and metal halide as a metal halide Three discharge lamps each containing about 0.6 mg of SnI ₂ were produced, and the light emission characteristics when the lamps were operated at the rated power of 35 W were examined. The results shown in Table 1 were obtained.

[0030]

[Table 1]

As is clear from Table 1, the three types of lamps according to the present invention have a luminous efficiency Lm / W and a color rendering property (color rendering index) Ra, as compared with the conventional mercury-filled lamp. Lamp voltage V
L is also low, which is a value that does not pose a problem in practical use in consideration of lighting by an electronic lighting circuit, and it was confirmed that predetermined electrical characteristics could be maintained and emission characteristics were improved.

Table 2 shows the results of an investigation on the instantaneous restart characteristics. The lamps a to a in which only the rare gas (xenon Xe) charging pressure was changed to about 3 atm in each of the above lamps and lamps are shown. Produce three each,
The pulse voltage (kV) required for restart was compared.

[0033]

[Table 2]

As is apparent from Table 2 above, the instantaneous restart characteristic greatly changes depending on the sealing pressure of xenon Xe regardless of the light-emitting substances a to a and a to a. It was confirmed that the lamp was easily lit with a lower pulse voltage than the lamp.

The right end in Table 2 shows the result of examining the thermal shock strength of the arc tube 1 (translucent airtight container 2). Indicates the damage occurrence status. These are the above lamps and a
a corresponding to a rated 35 W and an increase of 20% of the rated value 4
The lamp is repeatedly turned on and off with a power of 2 W (ON for 60 minutes-OFF for 5 minutes), and the arc tube 1 (translucent airtight container 2) and the arc tube 1
The occurrence of breakage of the reflecting mirror and the light transmitting cover due to the rupture of the (light transmitting airtight container 2) was examined.

As a result, each of the above lamps and a
In ~ a, there was no rupture of the arc tube 1 (translucent airtight container 2) after 1500 hours of rated power lighting (2000 hours of rated life). However, when the rated power is increased by 20%, one of the three lamps of the conventional lamp a filled with about 3 atm of mercury and xenon is lit by about 80%.
It ruptured at 0 hours and scratched the reflector. No burst occurred in the other lamps-and a-a.

In experiments conducted by the present inventors, thallium T
l, the amount of halide of indium In or tin Sn is 5 to 20 per cc of the volume of the light-transmitting hermetic container 2.
0 mg is required, and if it is less than 5 mg / cc, it is difficult to obtain a lamp voltage of 30 V or more, and the current must be increased, which leads to an increase in the cost of a lighting circuit member, which is not preferable. On the other hand, if it exceeds 200 mg / cc, the discharge becomes unstable and the arc bends and flickers, or when the lamp L1 is vertically pointed, unevaporated halide is present at one end of the arc tube 1 (translucent airtight container 2). The light emission color may change remarkably above and below the arc tube 1.

The rare gas charging pressure is 1 atmosphere (normal temperature =
25 ° C.) or higher, and if the pressure is lower than 1 atm, there is a problem that discharge is difficult to occur at the time of starting and instantaneous discharging is difficult, and the starting characteristics are deteriorated. The sealing pressure is preferably about 1 to 5 atm (normal temperature). . On the other hand, if the filling pressure is 5 atm (normal temperature) or more, the pressure expands at the time of lighting and becomes 5 to 7 times the pressure. If the airtight container is damaged or distorted, a crack is generated from this portion and the container is easily ruptured. Further, the metal vapor discharge lamp L
1 is manufactured by heating an intermediate portion of a quartz glass tube forming the translucent airtight container 2, placing the glass tube in a mold having a spheroidal hollow portion, and blowing up the glass tube. Then, the softened intermediate portion is expanded and pressed against the mold wall to form a spheroidal portion.

First, a metal foil 4a to which the discharge electrode 5a and the outer conductor 6a are welded is inserted from one end of the quartz glass tube, and the tip of the discharge electrode 5a is rotated while flowing nitrogen into the glass tube. The portion of the glass tube where the metal foil 4a is interposed at the position protruding into the oval portion is heated from the outside with an oxyhydrogen burner, and when the glass tube is melted and softened, it is crushed by a pincher to form an airtight sealing portion 3a. .

Next, thallium iodide TlI, which is a luminescent substance, is weighed in advance from the open end of the quartz glass tube in an inert gas such as argon Ar or a nitrogen atmosphere. After sealing, discharge electrode 5b
And, the metal foil 4b to which the outer conductor 6b is welded is inserted, and set so that the distance between the distal ends of the discharge electrodes 5a and 5b becomes a predetermined distance.

Next, the other end of the quartz glass tube is hermetically attached to an exhaust device, and after evacuation of the inside of the glass tube, xenon Xe of a predetermined pressure is sealed therein. Blow.

Next, the spheroidal portion is cooled with liquid nitrogen or the like to condense the encapsulation in the tube while the metal foil 4b
Is heated by an oxyhydrogen burner from the outside, and when the glass tube melts and softens, it is crushed by a pincher to form an airtight sealing portion 3b. Finally, the glass tube portion remaining on the side of the outer conductor 6b from the sealing portion 3b is blown to complete the arc tube 1.

In the manufacturing process of the discharge lamp described above, the portions where the sealing portions 3a and 3b at both ends of the quartz glass tube forming the light-transmitting hermetic container 2 are provided have the thickness of each glass tube set to 0. With a difference of about 1 to 0.6 mm (10 to 40%), the thick glass tube side may be sealed first, and the thin glass tube side may be sealed later.

This is because, for example, a swelling portion such as a spheroidal portion and one glass tube are formed with the same thickness, and after forming a sealing portion 3a on one side of the glass tube, the other thin portion is formed. If the sealing portion 3b on the glass tube side is formed,
On the side to be sealed later, the glass tube is thin because the glass tube is thin under the same heating conditions, and the work can be performed in a short time. Further, if the operation time is the same, heating by a burner or the like can be weakened.

The other advantage of the thinning of the glass tube is that the time for exposure to a high temperature and the temperature are reduced, so that the luminous substance is prevented from evaporating and scattering and the metal foil 4b,
Oxidation of the discharge electrode 5b and the outer conductor 6b is prevented, and various characteristics such as reduction in variations in light emission characteristics and electric characteristics can be improved. In addition, the fact that the amount of heating of the other glass tube can be reduced can save heating energy and reduce the pressure in the glass tube, thereby preventing the glass melted portion from bursting and improving the yield.

Further, the quartz glass tube forming the light-transmitting airtight container 2 may be formed separately from the swelling portion such as the spheroidal portion and the glass tube at both ends, and then joined later to be integrated. ,
It can be applied to the case where the thickness of the glass tubes at both ends is made different.

The short arc type metal vapor discharge lamp L1 is used, for example, as a light source of a light projecting device T shown as an embodiment in FIG. This floodlighting device T
Is for a liquid crystal projector, and an electrically insulating base 7 made of ceramic is joined to one sealing portion 3b of the arc tube 1 of the metal vapor discharge lamp L1 via a heat-resistant adhesive (not shown). Have been. In the drawing, reference numeral 8 denotes a bowl-shaped reflecting mirror formed of a paraboloid of revolution or spheroidal surface having a reflecting surface 81 such as a dichroic film or an aluminum film formed on the inner surface, and 82 is formed on the back surface of the reflecting mirror 8 at the center. Through hole 83
It is a base end part having. The discharge lamp L1 is disposed such that the approximate center between the discharge electrodes 5a and 5b is aligned with the focal position of the reflecting mirror 8, and the base 7 is provided in the through hole 83 of the reflecting mirror 8 with a heat-resistant adhesive (not shown). ) Is fixed through the joint.

9 is a lighting circuit for the discharge lamp L1,
The terminal pins 71 of the base 7 connected to the outer conductor 6b and the outer conductor 6a are connected to the outer conductor 6a via power supply lines 91 and 92.

The light emitting device T is connected to the terminal pins 7 of the base 7 of the discharge lamp L1 from the lighting circuit 9 via the power supply lines 91 and 92.
Lights when power is supplied to the first conductor 1 and the outer conductor 6a. Then, the light beam reflected by the reflecting surface 81 of the reflecting mirror 8 (in the case of a dichroic film, only a light beam of a predetermined wavelength) is radiated forward of the reflecting mirror 8, and further, a lens and a reflecting mirror (both are not shown). ), The liquid crystal panel (not shown) is irradiated, and an image of the liquid crystal panel can be projected on a screen via a lens (not shown).

Since the light projecting device T is provided with the metal vapor discharge lamp L1 having the above-described functions and effects, it has the same luminous characteristics and starting characteristics as those of the conventional product, and can process the replacement lamp with high safety. it can.

The present invention is not limited to the above embodiment. For example, the shape of the arc tube constituting the discharge lamp is not limited to the shape in which the light emitting portion has a spheroidal shape, and may be a spherical shape, an elliptical shape, a cylindrical shape, or the like. The material is not limited to quartz glass and may be a translucent ceramic such as alumina. Further, the formation of the sealing portions at both ends of the container is not limited to the crushing sealing by the pincher, but may be a sealing portion shape in which the glass is simply melted and welded to the metal foil without using the pincher.

The sealing portion is not limited to the one formed at both ends of the hermetic container. As another embodiment, a metal having a sealing portion 3a formed at one end of the container 2 shown in a front view in FIG. The vapor discharge lamp L2 has the same operation and effect as described above. Further, the translucent airtight container 2 is not limited to a single container, and may have a double tube structure as shown in FIGS. 4 and 5 as a partial sectional front view and a front view as another embodiment. The metal vapor discharge lamp L3 shown in FIG. 4 surrounds the arc tube 1 and has both ends 21 and 21 respectively having sealing portions 3a and
An outer container 20 made of quartz glass welded to 3b is provided. In the metal vapor discharge lamp L4 shown in FIG. 5, the arc tube 1 is supported on the lead wires 42, 43 of the stem 41 via the band-shaped members 44, 44, and the stem 41 is formed of hard glass or quartz glass. The discharge lamps L3 and L4, which are housed in the vessel 20 and sealed, comprise a double tube.
To prevent oxidation, to form an ultraviolet shielding or an ultraviolet shielding coating, and to protect the container 2 of the arc tube 1 from rupture.

The present invention is applicable to any of the above-mentioned various regulatory ranges such as the shape and size of the light-transmitting hermetic container, the material and amount of metal halide, the rare gas material and sealing pressure, and the distance between discharge electrodes. If so, the results satisfied the predetermined effects.

The light projecting device of the present invention is used for general lighting indoors and outdoors, for store lighting, for the backlight of a projector, or for the headlights of automobiles and railway vehicles which need to be instantly re-lit because of many flashing operations. Can be widely used for such as.

[0055]

According to the present invention, a metal halide selected from thallium, indium, and tin emits light to obtain predetermined light emission and electric characteristics, and to change the color even when the input is changed. Variations in characteristics can be reduced.
Further, even if the lamp is turned off, the restarting characteristic that can be immediately turned on is improved, and the internal pressure is lower than before, so that the container is prevented from bursting. Furthermore, since mercury is not used, a high-pressure metal vapor discharge lamp having various advantages such as easy disposal of a lamp whose life has expired and contribution to environmental protection can be provided.

According to the fourth aspect of the present invention, since the discharge lamp having the effects of the first to third aspects is provided, the luminous characteristics can be improved and the current capacity of the circuit for restarting is set low. Therefore, it is possible to provide a light emitting device that can reduce the cost of the lighting circuit and can reduce damage to the reflector and the cover due to the rupture of the arc tube.

[Brief description of the drawings]

FIG. 1 is a front view of a short arc type metal vapor discharge lamp showing an embodiment of the present invention.

FIG. 2 is a partial cross-sectional side view of the light projecting device showing the embodiment of the present invention.

FIG. 3 is a front view of a short arc type metal vapor discharge lamp showing another embodiment of the present invention.

FIG. 4 is a partial cross-sectional front view of a short arc type metal vapor discharge lamp showing another embodiment of the present invention.

FIG. 5 is a front view of a short arc type metal vapor discharge lamp showing another embodiment of the present invention.

[Explanation of symbols]

 L1 to L4; metal vapor discharge lamp 1; arc tube 2; translucent airtight container 3a, 3b; sealing portion 4a, 4b; metal foil 5a, 5b; discharge electrode T; light projecting device 8; circuit

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Toshio Hiruda 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Lighting & Technology Corporation

Claims (4)

[Claims] 1. A light-transmitting airtight container having an inner volume of 1 cc or less; a discharge electrode opposed to the airtight container at a discharge interval of 5 mm or less; thallium, indium, and tin sealed in the airtight container And a substantially mercury-free discharge medium comprising a metal halide containing at least one selected from the group consisting of: and a noble gas. 2. The metal vapor discharge lamp according to claim 1, wherein the amount of metal halide containing at least one selected from thallium, indium and tin is 5 to 200 mg / cc. 3. The metal vapor discharge lamp according to claim 1, wherein the rare gas is at least one selected from argon, krypton, and xenon, and is sealed at 1 atm or more. 4. A reflector comprising: a reflector; a metal vapor discharge lamp according to claim 1 disposed in the reflector; and a lighting circuit connected to the discharge lamp. Light emitting device characterized by the above-mentioned.