JPH0325854A - Microwave driven electrodeless lamp - Google Patents

Abstract

PURPOSE: To provide a microwave-driven electrodeless lamp which can emit light in the visible range by including a light-transmitting container filled with mercury, tin, indium, and at least two kinds of halogen elements. CONSTITUTION: A light source device 1 has a cup-shaped reflector 2, which reflects light projected from a lamp and which defines a part of a microwave cavity 6. Microwaves introduced into the microwave cavity 6 via a coupling slot 2a are confined therein and absorbed into the lamp 7 to excite the contents packed in the lamp 7. The contents include mercury, tin, indium, and at least two kinds of halogen elements. The light produced from the electrodeless lamp is white light with good color reproducibility and high efficiency. Also, the lamp operates stably even if its operating conditions fluctuate widely.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to an electrodeless lamp driven by microwaves, and more specifically relates to an electrodeless lamp for emitting light mainly in the visible light region. It concerns electrode discharge lamps. Metal halide discharge lamps have been known for a long time.

Typical electroded metal halide discharge lamps are disclosed in U.S. Pat. Nos. 3,882,345 and 4,001,626, and electrodeless metal halide discharge lamps are disclosed in U.S. Pat. It is disclosed. However, the electrodeless lamp disclosed in US Pat. No. 4,705,987 is not driven by microwaves, but uses rf excitation methods.
f! In the case of electrode discharge lamps, the discharge phenomenon occurs on the basis of thermal excitation via particle collision processes, while in the case of electrodeless discharge lamps, the electrons are directly stimulated by an external excitation source. It is something that is excited.

Therefore, the discharge phenomena are different between electrode lamps and electrodeless lamps, and therefore, it is usually impossible to directly apply techniques related to electrode discharge lamps to electrodeless discharge lamps. Furthermore, in the case of electrode discharge lamps,
Additional problems exist, such as electrode deterioration and arc tube wall blackening phenomena. As a result, such prior art electroded metal halide discharge lamps tend to exhibit wide variations in color production due to the inevitable variations in operating conditions. RF-excited discharge lamps do not use electrodes. However, an RF coil must be used to impart RF energy to the arc tube filling, thus limiting the output of the generated light. The present invention has been made in view of the above points, and it is an object of the present invention to eliminate the drawbacks of the prior art as described above and to provide an improved electrodeless discharge lamp driven (excited) by microwaves. Purpose. Another object of the present invention is to
An object of the present invention is to provide a microwave-driven electrodeless discharge lamp capable of generating light substantially in the visible light region. A further object of the present invention is to provide a microwave-driven electrodeless metal halide capable of generating stable white light with high efficiency and good color reproduction even under widely varying operating conditions. An object of the present invention is to provide a discharge lamp. Still another object of the present invention is to provide a microwave-driven electrodeless discharge lamp that is simple in construction, stable and reliable in operation, and has a long life.

According to the present invention, there is provided a microwave-driven electrodeless device comprising an enclosure or container made of a light-transmitting material and filled with mercury, tin, indium, and at least two types of halogen elements. A discharge lamp is provided. These halogen elements are preferably in the form of halides, most preferably in the form of metal halides such as indium halides and mercury halides. In a preferred embodiment, lithium halide is additionally added. A noble gas, preferably argon, is also charged into the enclosure as a starting gas at a pressure in the range of about 20 to 200 Torr. The enclosure is comprised of a light-transmissive material, preferably quartz or fused silica. As another example, the enclosure could be constructed from sapphire or any other desired material, such as spinel. In a preferred embodiment, the fill contained within the enclosure is mercury (Hg). Iodine (I), chlorine (Cl), tin (S
n). and indium (In), and these elements are set so as to satisfy the conditional relationship in the following molar ratio range between the filling materials. In addition, in the following conditional relationships, X: I + C l and M = Sn
Assume that +In. (1) 0.1<X/Hg<0.4 (2) 0.04<M/Hg<0.12(3) M
<0.3X (4) 0.05<In/Sn<0.2 (5) 0.5<I/CI<2.0 Furthermore, when adding lithium (Li), the following additional molar ratio The range relation should be satisfied. (6)
0.1<Li/M<10.0 In this case, the amount of halogen is increased by 1 gram atom/halogen/1 gram atom of lithium. Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring first to FIG. 1, there is shown schematically a microwave-driven electrodeless discharge light source device 1 comprising an electrodeless discharge lamp 7 constructed in accordance with one embodiment of the present invention. As shown, the light source device 1 has a five-cup shape or reflector 2, which reflects the light emitted from the lamp and which also partially defines a microwave cavity 6. . In the illustrated example, the reflector 2 has a cup shape, that is, a hemispherical shape, and the light emitted from the lamp 7 is reflected by the reflector 2 and taken out to the outside as parallel rays. However, caution should be taken. However, the reflector 2 can have any shape, for example, an elliptical cross section or other shapes. The reflector 2 is formed with a coupling slot 2a through which the microwave can be introduced into the microwave cavity 6, and furthermore has at least one cooling slot 2b formed therein, Via it it is possible to direct a cooling gas, such as air, towards the lamp 7.

The light source device 1 further includes a waveguide 3, one end of which is attached to the beam reflector 2. magnetron 4
is attached to the other end of the waveguide 3, so that the microwave is emitted from the microwave antenna 4a of the magnetron 4, and the microwave thus emitted propagates along the waveguide 3 and is coupled. is supplied into the microwave cavity 6 through the slot 2a. A metal mesh 5 is cup-shaped or fixed to the opening of the reflector 2, so that a microwave cavity 6 is defined by the reflector 2 and the mesh 5. The mesh 5 allows the light emitted from the lamp 7 to pass through it, but it prevents the microwaves from passing through. Therefore, the microwave air W46 is connected via the coupling slot 2a.
The microwaves introduced into the lamp 7 are confined therein and absorbed into the lamp 7 to excite the contents filled inside the lamp 7. In a preferred embodiment, the microwave cavity 6 is configured as a cavity resonator, so that the microwaves introduced into the cavity 6 are in a resonant state and the microwave energy is efficiently absorbed by the lamp 7. is possible.

Incidentally, it is desirable to set such a resonant state so that the lamp 7 is in a resonant state while it is lit. Furthermore, as another example, it is also possible to operate such a lamp in a non-resonant state, ie with microwaves having a frequency different from the natural frequency of the microwave cavity 6. The detailed configuration of the microwave lamp 7 is shown in cross section in Figure 2. As shown, in the illustrated example, the lamp 7 has an enclosure or container 7a, which is substantially spherical in shape and made of a light-transmissive material, such as quartz. There is. However, any other suitable material may be used if desired. The enclosure 7a can also take any other desired shape, such as elongated or elliptical. The lamp 7 further has a filling contained inside the enclosure 7a. As explained in detail below, the present invention includes:
This enclosure 7a has particular features regarding the structure of the filling to be accommodated within the enclosure 7a. The spherical enclosure 7a is fixed to the tip of a support rod 8 extending into the microwave cavity 6 from the outside. The support rod 8 is mounted at its proximal end on the rotating shaft of the motor 9, so that the enclosure 7a can be rotated about the horizontal axis at the desired speed. As mentioned above, in this embodiment, the cooling air jet is formed by the cup-shaped glue reflector 2.
is directed towards the lamp 7 through a cooling slot 2b formed in the top of the lamp, so that the enclosure 7a can be uniformly exposed to the cooling air jet. Such a cooling configuration is particularly effective for maintaining the temperature of the enclosure 7a uniform and constant, which contributes to stabilizing the luminous characteristics and extending the life of the lamp 7. do.

As mentioned above, the lamp 7 is an enclosure (with a predetermined shape).
It has a container) 7a and a filling hermetically sealed within the enclosure 7a. In a preferred embodiment, the filling comprises:
Mercury (Hg), tin (Sn), indium (In). and at least two types of halogen elements. Halogen includes iodine, chlorine, fluorine, bromine, and astatine, and any of these elements can be used.

In one embodiment, iodine and chlorine are selected, but any of the halogens can be selectively used. The halogen is preferably converted into a metal halide, at least during operation.

For example, in Examples containing mercury, tin, indium, iodine, and chlorine, it was unexpectedly found that the following forms of metal halides were actively involved in the light-emitting operation, particularly in the visible light region.

Indium chloride Mercury chloride Indium iodide Mercury iodide Tin chloride Tin iodide A noble gas such as argon is preferably contained within the enclosure 7a as a starting gas. However, if the light emitting operation can be started by any other method other than the noble starting gas, it may not be necessary to use such a starting gas. In a preferred embodiment of the invention, argon is contained within the enclosure 7a as the starting gas at a pressure of, for example, 20 to 200 Torr.
Alternatively, it is also possible to use one or more of other noble gases, such as helium, neon, xenon, and krypton, as the starting gas. However, helium and neon gradually diffuse through the quartz wall. Therefore, if helium or neon is used, some method should be applied to retain it within the enclosure 7a. In a preferred embodiment of the invention, the molar ratio of the contents of the filler should be set within the following range: In addition, in the following conditional relational expression, it is assumed that the relationships of X = I + C l and M = Sn + In hold 6 (1) 0.1 <
Hg<0.4 (2)-'0.04<M/Hg<0.1 2(3)M<
0.3X. (4) 0.05<In/Sn<0.2 (5) 0.5<I/Cl<2.0 Furthermore, in order to further improve the red part in the visible light region, lithium may be added. When adding lithium (Li), the following additional molar ratio range 4 relationship should be satisfied6 (6) 0.1<Li/M<10.0 In this case, the amount of halogen is The total mass W (in milligrams per cm' of volume of the enclosure 7a) of the components of the filling, namely M and It is desirable to set it within the range of .

(7) 0. 1<W<1.0 It should be noted that such a filling can be suitably used in electrodeless lamps. However, when such a filling is used in an electrode lamp, excessive wall blackening due to evaporated electrode material occurs, especially at the high I/Cl ratio, and at the lower end of the I/Cl range. Therefore, such a filling cannot be used effectively in an electrode lamp. Mercury and! An electrodeless lamp 7 containing iodine, chlorine, and iodine in the molar ratio range mentioned above and argon as a starting gas was actually manufactured, and was heated using microwaves in the apparatus shown in FIG. The light emitted from such a lamp 7 was analyzed in terms of its spectrum. The resulting spectral distribution is shown in the graph of FIG.

Lamp 7 operates at 500 watts and has a total illuminance of 397
It had 98 lumens. The operating temperature was 860°C.

As can be understood from Figure 3, intense light emission is obtained, especially in the visible light region.Surprisingly, this spectral distribution is continuous, and very efficient molecular radiation (light emission by molecules) is obtained. ) indicates the existence of Continuous light emission over a wide range in the visible light region is one of the features of the present invention. The power distribution was also measured, and the results are as follows.

``Yoryu Kosorito Bayuni''-2L Kamimi-201-25
0 0.6 251-300 12.7 301-350 29.9 351-400 28.2 401. -450 40.0451-500
35.0 501-550 32.4 551-600 28.3 601-650 5.4 651. -700 5.7701-750
3.7 75↓-800 3.5 801-850 1. 085
1-880 0. FIG. 4 shows the spectral distribution of light emitted from another electrodeless lamp 7 which additionally contains lithium in addition to the elements in the above-mentioned embodiment in order to particularly improve the red part in the visible light region. There is. The spectral distribution shown in FIG. 4 shows an improvement in light generation, especially in the red part of the visible light range. The lamp 7 of this example was also operated in the apparatus 1 shown in FIG. 1 with a microwave power of 500 watts. The total illuminance obtained was 52994 lumens, and the operating temperature was 1000°C. The power distribution in this case was also measured, and the results are shown below. Staff 111 and 201-250 251-300 301-350 351-400 401-450? j ■ nie 2' d arm L 1. 4 14. 3 32. 0 33. 2 35. 3 451-500 31. 2501
-550 40.8551-600
38.3601-650
12. 0651-700
27.0701-750 6.87
51-800 9.8801-85
0 7.6851-880
4.7 Within the range of molar ratios mentioned above, the purest colored light can be obtained by adjusting the In/Sn ratio. In this case, SnI, SnC
In.l and HgCl give a greenish color, while In. I
nI and HgI give a purplish color. Moreover, it is possible to obtain optimal luminescent performance by adjusting M and X within the above-mentioned molar ratio ranges without forming condensates. It should be noted that all of these molecules have high vapor pressures, and neither tin nor indium will react with quartz. Here, high vapor pressure means that these substances can easily evaporate away from the wall and maintain a high density within the operating plasma, which means that the surrounding This contributes to high output and efficient operation without being significantly affected by the body's operating temperature. It should be further noted that Hg, chlorine, iodine,
and other inclusions such as argon do not react with quartz. Accordingly, the filling components of the present invention are relatively stable and do not degrade, thus allowing the intensity and color of the light produced to remain substantially constant. Filling components within the above-mentioned molar ratio range cannot be used in electroded lamps since they cause electrode corrosion. For example, if such a filling component were used in an electroded lamp, the electrodes would be attacked by CI or chlorine and corrode or crack. Additionally, iodine causes tungsten, a material commonly used in such electrodes, to be transported from the electrode to the lamp wall.

As a result, it is not possible to use the filling components of the present invention, especially those within the above-mentioned molar ratio ranges, in electroded lamps, and they can only be used effectively in electrodeless lamps. It is possible. It should be noted that all of the packing components of the present invention are between 700 and 9
It has high vapor pressure in the operating lamp temperature range of 00℃. As explained in detail above, the present invention provides a microwave actuator having a sealed enclosure made of a light-transmitting material and a filling hermetically contained within the enclosure. A type electrodeless lamp is provided.

The fill has a unique composition containing mercury, tin, indium, and at least two halogen elements (preferably iodine and chlorine).

When improving the red part in the visible light range,
For example, it is possible to add lithium to the filling.

Therefore, according to the present invention, there is provided a microwave pulsed electrodeless lamp that can effectively generate light substantially in the visible light region. The light emitted from the electrodeless lamp of the present invention is white light with good color reproduction and high efficiency. Furthermore, the light emitted from the electrodeless discharge lamp has stable operation even under widely varying operating conditions, and has a long life. Furthermore, the light generated from the present microwave-driven electrodeless lamp has a continuous spectral distribution over a wide range of visible light.

Although specific embodiments of the present invention have been described in detail above, the present invention should not be limited only to these specific examples, and various modifications may be made without departing from the technical scope of the present invention. Of course, it is possible.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing a microwave-driven electrodeless discharge light source device suitable for applying the present invention, and Fig. 2 shows the structure of an electrodeless lamp installed in the light source device of Fig. 1. FIG. 3 is a graph showing the spectral distribution of light emitted from a microwave-driven electrodeless lamp containing mercury, tin, indium, iodine, and chlorine according to an embodiment of the present invention. FIG. 4 shows the spectral distribution of light emitted from a microwave-driven electrodeless lamp which additionally contains lithium in addition to the elements described with respect to FIG. 3 according to another embodiment of the invention. It is a graph diagram. (Explanation of symbols) 7: Electrodeless lamp 7a: Envelope (container)

Claims (1)

[Claims] 1. In a microwave-driven electrodeless lamp, an enclosure is made of a light-transmitting substance and filled with mercury, tin, indium, and at least two different types of halogen elements. An electrodeless lamp characterized by having a body. 2. The electrodeless lamp according to claim 1, wherein the enclosure is further filled with lithium. 3. The electrodeless lamp according to claim 1 or 2, wherein the at least two types of halogen elements include iodine and chlorine. 4. Any one of claims 1 to 3
2. The electrodeless lamp according to item 1, wherein the envelope is further filled with a starting rare gas.