JP2004281306A - Electrodeless discharge lamp, its lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an approximately spherical electrodeless discharge lamp with a cavity portion having a hard-to-peel fluorescence film applied to the side wall, its lighting device for lighting the electrodeless discharge lamp, and a lighting system therewith. <P>SOLUTION: The electrodeless discharge lamp comprises an approximately spherical bulb 1 filled with discharge gas containing at least mercury and rare gas and having the sectionally recessed cavity portion 2, the first fluorescence film 3 applied to the inner wall of the bulb 1, a second fluorescence film 4 applied to the side wall of the cavity portion 2 of the bulb 1, an induction coil 5 arranged in the cavity portion 2 for supplying a high frequency highly magnetic field to the discharge gas, and a columnar core 6 on which the induction coil 5 is wound. A binder which is added to the second fluorescence film 4 for increasing the application strength of the second fluorescence film 4 has a weight % larger than that of a binder which is added to the first fluorescence film 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrodeless discharge lamp that emits light by applying a high-frequency electromagnetic field to a bulb having a discharge gas sealed therein, an electrodeless discharge lamp lighting device for lighting the electrodeless discharge lamp, and an electrodeless discharge lamp and an electrodeless discharge lamp The present invention relates to a lighting device provided with a lighting device.
[0002]
[Prior art]
A conventional example of this type is described in Japanese Patent Application Laid-Open No. 7-272688. This electrodeless low-pressure mercury vapor discharge lamp is designed to prevent the interaction between the phosphor films J5A and J5B and the particles from the discharge space J2. As shown in FIG. 6, mercury and a rare gas are filled. And a discharge vessel J1 that hermetically surrounds the discharged discharge space J2.
[0003]
The discharge vessel J1 has a translucent color-circling portion J3A and a concave portion J3B in which a coil J10 for generating a high-frequency magnetic field is inserted. Phosphor films J5A and J5B are provided on at least a part of the surface J4 of the discharge vessel J1 facing the discharge space J2.
[0004]
Further, at least a part of the phosphor film J5B has a protective layer J6B of aluminum oxide particles having a coating amount of 10 to 500 μg / cm ² , and the protective layer J6B consumes mercury during the lamp life. And / or changes in color coordinate points are reduced.
[0005]
With the above configuration, it is possible to prevent the action between the phosphor films J5A and 5B and the particles from the discharge space J2 despite the relatively strong electric field and the relatively high temperature in the lamp.
[0006]
[Patent Document]
JP-A-7-272688
[Problems to be solved by the invention]
By the way, in the electrodeless low-pressure mercury vapor discharge lamp having the recessed portion J3B as described above, a phosphor film is formed on the surface J4 of the discharge vessel J1 in order to effectively use the ultraviolet light from the discharge plasma formed in the lamp. Not only is J5A formed, but also a phosphor film J5B is formed on the surface of the recessed portion J3B inside the discharge vessel J1. The thicknesses of the phosphor films of the ordinary phosphor film J5A and the phosphor film J5B are often substantially equal in order to simplify the production process and reduce the production cost.
[0008]
Here, the phosphor film J5A is applied to the inner surface of the sphere, and the phosphor film J5B is applied to the surface of a substantially vertically standing column. Since the weight from the upper portion of the body film J5B is applied, the adhesive strength of the phosphor film J5B to the surface of the cylinder is weaker than the adhesive strength of the phosphor film J5B to the inner surface of the sphere, and the discharge container J1 may vibrate. There was a problem that it was easily peeled off.
[0009]
Also, in order to increase the luminous efficiency of the electrodeless low-pressure mercury vapor discharge lamp, the amount of light leaking from the recessed portion J3B to the outside and the amount of light emitted from the surface J4 of the discharge vessel J1 to the outside are considered. When the thickness of the phosphor film J5B is increased and the thickness of the phosphor film J5A is reduced, the phosphor film J5B is more easily peeled off due to the weight of the film thickness.
[0010]
Further, during the operation of the electrodeless low-pressure mercury vapor discharge lamp, the phosphor film gradually deteriorates due to the collision of electrons and ions in the discharge plasma. However, the electrons and ions closer to the coil J10 are discharged to the discharge vessel J1. The collision energy is larger than the electrons and ions in the phosphor film. Therefore, the phosphor film J5B closer to the coil J10 is more likely to deteriorate than the phosphor film J5A.
[0011]
The present invention has been made in view of the above problems, and an object of the present invention is to provide a substantially spherical electrodeless discharge lamp having a cavity, in which the phosphor film applied to the side wall of the cavity is peeled off. It is an object of the present invention to provide an electrodeless discharge lamp, an electrodeless discharge lamp lighting device for lighting the electrodeless discharge lamp, and a lighting device including the electrodeless discharge lamp and the electrodeless discharge lamp lighting device.
[0012]
[Means for Solving the Problems]
An electrodeless discharge lamp according to claim 1, wherein a discharge gas containing at least mercury and a rare gas is enclosed therein and a substantially spherical bulb having a cavity having a concave cross section, and a second bulb applied to the inner wall of the bulb. A first phosphor film, a second phosphor film in the bulb and applied to the side wall of the cavity, an induction coil disposed in the cavity and supplying a high-frequency electromagnetic field to the discharge gas, and an induction coil. A weight ratio of a binder added to the second phosphor film and increasing the coating strength of the second phosphor film is added to the first phosphor film. It is characterized in that it is larger than the weight% of the binder to be obtained.
[0013]
In such an electrodeless discharge lamp, the application strength of the second phosphor film applied in the axial direction of the cavity is equal to or higher than the application strength of the first phosphor film.
[0014]
The electrodeless discharge lamp according to claim 2 is the electrodeless discharge lamp according to claim 1, wherein the weight% of the binder added to the second phosphor film is added to the first phosphor film. The weight percentage of the binder is from 2 to 20 times.
[0015]
In such an electrodeless discharge lamp, even when the thickness of the second phosphor film is increased, the application strength of the second phosphor film is equal to or higher than the application strength of the first phosphor film. Become.
[0016]
An electrodeless discharge lamp according to a third aspect is the electrodeless discharge lamp according to the first or second aspect, wherein the binder is a metal oxide.
[0017]
The metal oxide is resistant to impact due to collision of electrons or ions, and can further increase the coating strength of the second phosphor film as compared with the electrodeless discharge lamp according to claim 1 or 2.
[0018]
An electrodeless discharge lamp according to a fourth aspect of the present invention is the electrodeless discharge lamp according to any one of the first to third aspects, wherein the weight% of the binder added to the second phosphor film is the second fluorescence. It is characterized by being from 1 to 10% of the body membrane.
[0019]
In such an electrodeless discharge lamp, even when the thickness of the second phosphor film is increased, the application strength of the second phosphor film is equal to or higher than the application strength of the first phosphor film. Become.
[0020]
An electrodeless discharge lamp according to a fifth aspect is characterized in that, in the electrodeless discharge lamp according to any one of the first to fourth aspects, the thickness of the second phosphor film is 300 μm or less. is there.
[0021]
In such an electrodeless discharge lamp, even when the thickness of the second phosphor film is increased, the application strength of the second phosphor film is equal to or higher than the application strength of the first phosphor film. Become.
[0022]
According to a sixth aspect of the present invention, there is provided the electrodeless discharge lamp according to any one of the first to fifth aspects, wherein the binder particles have a polygonal shape.
[0023]
Since the shape of the particles of the binder is polygonal, the contact surface area between the particles of the binder and the side wall of the cavity increases, and the application strength of the second phosphor film increases.
[0024]
An electrodeless discharge lamp lighting device according to a seventh aspect supplies high frequency power from several kHz to several tens of MHz to the electrodeless discharge lamp according to any one of the first to sixth aspects to light the electrodeless discharge lamp. It is characterized by the following.
[0025]
In such an electrodeless discharge lamp lighting device, the electrodeless discharge lamp is turned on at a high frequency, and the luminous efficiency of the electrodeless discharge lamp can be increased.
[0026]
An illumination device according to an eighth aspect of the present invention includes the electrodeless discharge lamp lighting device according to the seventh aspect, and lights the electrodeless discharge lamp according to any one of the first to sixth aspects. .
[0027]
BEST MODE FOR CARRYING OUT THE INVENTION
(Example 1)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a cross-sectional view of the present embodiment, and FIG. 2 shows the relationship between the second phosphor film thickness and the height at which the second phosphor film thickness starts to peel off. FIG. 3 shows a measuring method for measuring the relationship of FIG. 2, and FIG. 4 shows a circuit diagram of the electrodeless discharge lamp lighting device 9. FIG. 5 is a sectional view of a lighting device 10 including the electrodeless discharge lamp 8 and the electrodeless discharge lamp lighting device 9.
[0028]
Hereinafter, the configuration of each unit will be described.
[0029]
The bulb 1 is substantially spherical and has a discharge gas containing at least mercury and a rare gas sealed therein. Further, on the lower side of the valve 1, there are provided hollow portions 21a and 21b each having a bottom and being formed integrally with the valve 1 and having a concave cross-section and connected to each other. A mercury amalgam 23 for controlling a mercury vapor pressure is provided in an exhaust pipe 22 formed between the hollow portions 21a and 21b. Above the mercury amalgam 23, a glass rod 24 for fixing the mercury amalgam 23 and integrally formed with the bulb 1 is provided. The glass rod 24 is provided so as to protrude toward the tube axis direction of the exhaust pipe 22 so that the portion of the exhaust pipe 22 where the mercury amalgam 23 is provided communicates with the bulb 1.
[0030]
The material of the bulb 1 is a translucent material such as quartz glass, and the discharge gas is a rare gas such as mercury, argon, and krypton, and a metal halide. As an example, a xenon gas of about 300 Torr and a mixed gas of about 10 mg of sodium iodide, thallium iodide and indium iodide are used. Of course, another gas or metal may be used as the discharge gas to be filled.
[0031]
The first phosphor film 3 converts ultraviolet light emitted from mercury into visible light, and is applied together with the protective film 11 inside the bulb 1. As the material of the first phosphor film 3, calcium halophosphate, (Y, Gd) BO3: Eu as a red phosphor, CaPO4 as a green phosphor, and BaMgAll4O23: Eu as a blue phosphor are used.
[0032]
If the first phosphor film 3 is made thicker than necessary, the amount of visible light converted from ultraviolet light by the first phosphor film 3 to the outside of the bulb 1 decreases. The film thickness is about 20 μm, which is almost the same as that of a general fluorescent lamp.
[0033]
Further, a binder is added to the first phosphor film 3 in order to increase the application strength of the first phosphor film 3 to the inner surface of the bulb 1.
[0034]
As the binder, γ-Al 2 O 3 having a particle diameter of about 10 nm is used. When the particle shape of the binder is polygonal, the contact surface area with the inner surface of the bulb 1 is larger in the case of the polygonal shape than in the spherical shape, and the coating strength is easily increased. In addition, the binder is mixed with the phosphor turbid solution for forming the phosphor film, but the binder needs to be uniformly dispersed in the phosphor turbid solution to increase the coating strength. .
[0035]
The protective film 11 improves the luminous flux maintenance factor of the bulb 1 by suppressing the reaction between mercury and quartz glass, which is a material of the bulb 1. The material of the protective film 11 is alumina (Al2O3), silica, or the like. Fine particles such as (SiO2), titania (TiO2), ceria (CeO2), yttria (Y2O3), and magnesia (MgO) are used. The protective film 11 is preferably formed on the inner surface of the bulb 1 thinner than the first phosphor film 3 because it is desirable that the transmittance of the ordinary bulb 1 be higher. Further, the shape of the valve 1 does not have to be substantially spherical, and may be another shape such as a cylindrical shape.
[0036]
In this embodiment, the glass rod 24 is used to fix the mercury amalgam 23. However, instead of the glass rod 24, a metal that is difficult to directly combine with mercury, for example, a nickel-plated iron plate or a stainless steel plate is used. The surface of which the surface is mechanically roughened may be disposed in the exhaust pipe 22 above the portion where the mercury amalgam 23 is disposed. When such a device is provided, a portion of the amalgam mercury that has become a gas during normal lighting is trapped in this metal part, so that the light output can be quickly raised at the time of restart or the like.
[0037]
The second phosphor film 4 converts ultraviolet light emitted from mercury into visible light similarly to the first phosphor film 3, and has a hollow inside the bulb 1 and on side walls of the hollow portions 21a and 21b. The coating is applied along the axial direction of the portions 21a and 21b.
[0038]
Here, since the light transmitted through the side walls of the hollow portions 21a and 21b and the like does not irradiate around the bulb 1, the thickness of the second phosphor film 4 is increased so that the light is transmitted from this portion. It is desirable to reduce leakage. On the other hand, when the film thickness is increased, the weight of the upper portion of the second phosphor film 4 is added to the lower portion of the second phosphor film 4, and the bulb 1 is vibrated by the second phosphor film 4. In such a case, it is easy to peel off. For this reason, it is desirable to make the thickness of the second phosphor film 4 as small as possible.
[0039]
In order to satisfy this conflicting demand, the amount of the binder added to the second phosphor film 4 is made larger than the amount of the binder added to the first phosphor film 3, and The film thickness is made as large as possible while increasing the coating strength of the film 4. Here, as the binder added to the second phosphor film 4, the same as the binder added to the first phosphor film 3, γ-Al2O3 having a particle diameter of about 10 nm is used. When the particle shape of the binder is polygonal, the contact surface area with the sidewalls of the cavities 21a and 21b is larger than in the spherical shape, and the coating strength is easily increased.
[0040]
FIG. 2 shows the results of measuring the coating strength of the phosphor film while changing the amount of the binder added and the thickness of the phosphor film. An apparatus as shown in FIG. 3 was used for measuring the coating strength. A phosphor film to which a binder was added was applied to the inner surface of a ring-shaped glass tube 25 having an outer diameter of 28 mm, and the glass tube 25 was dropped by passing through a vertical rod 26. The height was gradually increased from the low height, and the height at which the phosphor film began to peel off and fall by the impact of the drop was recorded. If the height exceeds 100 cm, the glass tube 25 breaks, so that the measurable height was up to 100 cm.
[0041]
Referring to FIG. 2, as the thickness of the phosphor film increases, the height at which the phosphor film peels off decreases. However, the phosphor film peels off by increasing the amount of the binder added. It can be seen that the falling height can be increased. That is, by increasing the amount of the binder added, the coating strength of the phosphor film can be increased. It can be seen that the addition amount of the binder is 1% by weight to 10% by weight as compared with the 0.1% by weight of the phosphor film. Further, it can be seen that when the thickness of the phosphor film is set to 20 μm or more and 300 μm or less, there is an effect of increasing the amount of the binder added.
[0042]
In the present embodiment, the addition amount of the binder in the first phosphor film 3 is 0.5% by weight with respect to the phosphor, but the amount of the binder in the second phosphor film 4 is 0.5% by weight. The addition amount is 5.0% by weight based on the phosphor. When the addition amount of the binder of the first phosphor film 3 is increased to the same extent as the addition amount of the binder of the second phosphor film 4, the bulb 1 and the first phosphor film 3 Although the coating strength increases, the amount of the binder added to the first phosphor film 3 is preferably not increased because the amount of light applied to the outside of the bulb 1 decreases. In the present embodiment, the addition amount of the binder in the first phosphor film 3 is 0.5% by weight and the addition amount of the binder in the second phosphor film 4 is 5.0% by weight. % And the ratio is about 10 times, but in the applicant's experiment, if this ratio is set between 2 and 20 times, the first phosphor film 3 is made as thin as possible and the second phosphor It has been found that the film 4 can be made as thick as possible while increasing the coating strength. When the ratio is set as described above, the adhesive strength between the film thickness of the first phosphor film 3 and the film thickness of the second phosphor film 4 can be made substantially the same.
[0043]
Further, while the electrodeless discharge lamp 8 is turned on, the phosphor film is gradually degraded by electrons and ions in the discharge gas, but the second phosphor film 4 closer to the induction coil 5 has the first phosphor film. The impact of electrons and ions is larger than that of the phosphor film 3 described above, and the second phosphor film 4 deteriorates faster.
[0044]
For this reason, a metal oxide such as Al 2 O 3 which is strong against the impact of electrons and ions may be used as a binder added to the second phosphor film 4. Of course, such a binder may be added to the first phosphor film 3. In addition, the metal oxide used as the binder may be Y2O3 or MgO.
[0045]
The core 6 has a columnar shape and is erected and fixed to the base 12 so that one end of the core 6 faces the center of the bulb 1 and the other end faces the base 12 inside the cavity 2. In this embodiment, an Mn-Zn polycrystalline ferrite having a Curie temperature of about 240 to 280 [deg.] C. is used as a material of the core 6. When a material having low heat resistance is used as the material for covering the strip of the induction coil 5, Mn-Zn-based ferrite having a Curie temperature of 200 ° C. or less may be used. Here, the Mn-Zn-based ferrite contains Fe, Mn, and Zn as main composition components excluding the oxygen element, and is obtained by synthesizing and sintering respective oxides of Fe, Mn, and Zn. A main oxide for forming the Mn-Zn-based ferrite is, for example, Fe2O3, MnO, or ZnO. In addition, as long as it has a Curie temperature of 200 ° C. or lower, Mn—Zn-based single crystal ferrite or Ni—Zn-based polycrystalline or single crystal ferrite may be used.
[0046]
The induction coil 5 supplies the discharge gas inside the bulb 1 with a high-frequency electromagnetic field of several kHz to several tens of MHz, for example, a high-frequency electromagnetic field oscillating at 13.56 MHz. The induction coil 5 is wound along the pillar axis direction of the core 6, and the other is connected to the electrodeless discharge lamp lighting device 9. Here, the induction coil 5 is configured by winding a strip made of copper or a copper alloy around the core 6 a predetermined number of times, and it is desirable to use a litz wire to suppress loss. Litz wire is a composite wire composed of twisted fine wires, and has a larger surface area than a single wire of the same thickness, so it is possible to minimize the increase in loss due to the skin effect and proximity effect of the winding at high frequencies. it can.
[0047]
Further, as a material for covering the strip of the induction coil 5, a heat-resistant fluororesin, a heat-resistant enameled wire, or a silicon-based resin, which is an insulator, is used.
[0048]
A high-frequency current flows through the induction coil 5 when the electrodeless discharge lamp lighting device 9 operates, and a high-frequency electromagnetic field is generated around the induction coil 5. Next, electrons generated inside the bulb 1 are accelerated by the generated high-frequency electromagnetic field, and collide with atoms of the discharge gas to ionize the discharge gas, thereby generating new electrons. The electrons thus generated receive energy by a high-frequency electromagnetic field generated around the induction coil 5 and collide with the discharge gas atoms to give energy. The atoms in the discharge plasma are ionized or excited. The excited atoms emit light when returning to the ground state. This light emission is used as light energy.
[0049]
The member 30 has a columnar shape with a substantially circular cross section, and is provided so that the core 6 contacts the outside of the member 30.
[0050]
The base 12 is a casing formed by aluminum die casting, having a substantially convex cross section, and having an opening on the upper surface. The above-described member 30 is erected and fixed to the bottom surface of the base 12 so as to face the center of the valve 1.
[0051]
The electrodeless discharge lamp lighting device 9 has its output end (both ends of the matching circuit 17) connected to the above-described induction coil 5, and has a configuration as shown in FIG.
[0052]
That is, the electrodeless discharge lamp lighting device 9 rectifies the AC voltage from the commercial AC power supply AC into a pulsating DC voltage and outputs the rectifying circuit DB, and converts the pulsating DC voltage from the rectifying circuit DB into a desired pulsating DC voltage. A chopper circuit 15 that converts and outputs a DC voltage, a chopper control circuit 19 that controls the frequency of a switching element Q1 included in the chopper circuit 15, and a DC voltage E from a capacitor C1 is turned on / off by switching elements Q2 and Q3. The power conversion circuit 16 converts the voltage to a rectangular wave voltage, the drive circuit 20 transmits a drive signal to the switching elements Q2 and Q3 included in the power conversion circuit 16, and the drive circuit 20 controls the frequencies of the switching elements Q2 and Q3. A frequency control circuit 18 for transmitting a control clock signal, an inductor L2 and a capacitor When the impedance between the power conversion circuit 16 and the induction coil 5 is matched and the high-frequency power from the power conversion circuit 16 is efficiently transmitted to the induction coil 5, the induction coil connected to both ends of the matching circuit 17 5 and an IPD (intelligent power device) step-down circuit 14 for supplying power to the frequency control circuit 18, the chopper control circuit 19, and the like.
[0053]
The IPD step-down circuit 14 converts the DC voltage E into a DC voltage of, for example, 15 V, and supplies power to the frequency control circuit 18, the chopper control circuit 19, and the drive circuit 20. The IPD step-down circuit 14 includes a resistor R41, diodes D41 and D42, capacitors C41 to C44, an inductor L41, zener diodes ZD41 and ZD42, a photocoupler PC41, and an IC41.
[0054]
Of course, the configuration of the electrodeless discharge lamp lighting device 9 is not limited to this as long as it supplies a high frequency electromagnetic field of 13.56 MHz to the discharge gas inside the bulb 1.
[0055]
The electrodeless discharge lamp lighting device 9 and the electrodeless discharge lamp 8 constitute an illumination device 10 as shown in FIG.
[0056]
The shield case 13 covers the upper part of the bulb 1, and radiation noise from the bulb 1 is absorbed by the shield case 13. Of course, the lighting device 10 for turning on the electrodeless discharge lamp 8 is not limited to this.
[0057]
As described above, according to the present embodiment, the first phosphor film 3 can be made as thin as possible, and the second phosphor film 4 can be made as thick as possible while increasing the application strength.
[0058]
In addition, the coating strength of the second phosphor film can be equal to or more than the coating strength of the first phosphor film, and the second phosphor film is not affected by the weight or vibration of the film or by collision of electrons or ions. It can be prevented from easily peeling off.
[0059]
【The invention's effect】
In the electrodeless discharge lamp according to claim 1 or 2, the weight% of the binder added to the second phosphor film to increase the coating strength of the second phosphor film is included in the first phosphor film. Since it is larger than the weight% of the binder added, the application strength of the second phosphor film applied in the axial direction of the cavity should be equal to or higher than the application strength of the first phosphor film. Thus, the second phosphor film can be prevented from easily peeling off due to the weight of the film.
[0060]
In the electrodeless discharge lamp according to the third aspect, since the binder is a metal oxide, the second phosphor film can be protected from collision of electrons and ions, and the second phosphor film is easily peeled off. Can be prevented.
[0061]
In the electrodeless discharge lamp according to the fourth or fifth aspect, since the weight% of the binder and the thickness of the second phosphor film are appropriately adjusted, the second phosphor film is easily formed by the weight of the film. Peeling can be prevented.
[0062]
In the electrodeless discharge lamp according to the sixth aspect, since the shape of the particles of the binder is polygonal, the contact surface area between the particles of the binder and the side wall of the cavity can be increased, and the second phosphor film is formed. It can be prevented from easily peeling off.
[0063]
In the electrodeless discharge lamp lighting device according to the seventh aspect, since the electrodeless discharge lamp is lit at a high frequency of several kHz to several tens of MHz, the luminous efficiency of the electrodeless discharge lamp can be increased.
[0064]
An illumination device according to an eighth aspect includes the electrodeless discharge lamp lighting device according to the seventh aspect, and lights the electrodeless discharge lamp according to any one of the first to sixth aspects. According to any one of the first to seventh aspects, the effects of the invention described above can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the present embodiment.
FIG. 2 is a characteristic diagram showing a relationship between a second phosphor film thickness and a height at which the second phosphor film thickness starts to peel off.
FIG. 3 is a diagram showing a measuring method for measuring the relationship of FIG. 2;
FIG. 4 is a circuit diagram of an electrodeless discharge lamp lighting device.
FIG. 5 is a cross-sectional view of a lighting device including an electrodeless discharge lamp and an electrodeless discharge lamp lighting device.
FIG. 6 is a sectional view showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Bulb 2 Cavities 21a and 21b Cavity 3 First phosphor film 4 Second phosphor film 5 Induction coil 6 Core 8 Electrodeless discharge lamp 9 Electrodeless discharge lamp lighting device 10 Lighting device

Claims (8)

A substantially spherical bulb having a cavity with a concave cross section, in which a discharge gas containing at least mercury and a rare gas is enclosed; a first phosphor film applied to the inner wall of the bulb; A second phosphor film applied to the side wall of the hollow portion, an induction coil disposed in the hollow portion to supply a high-frequency electromagnetic field to the discharge gas, and a columnar core around which the induction coil is wound. The weight% of the binder added to the second phosphor film for increasing the application strength of the second phosphor film is larger than the weight% of the binder added to the first phosphor film. An electrodeless discharge lamp characterized in that: The weight percent of the binder added to the second phosphor film is from 2 to 20 times the weight percent of the binder added to the first phosphor film. An electrodeless discharge lamp as described. The electrodeless discharge lamp according to claim 1, wherein the binder is a metal oxide. The electrodeless electrode according to any one of claims 1 to 3, wherein the weight% of the binder added to the second phosphor film is 1 to 10% of the second phosphor film. Discharge lamp. The electrodeless discharge lamp according to any one of claims 1 to 4, wherein the thickness of the second phosphor film is 300 µm or less. The electrodeless discharge lamp according to any one of claims 1 to 5, wherein the shape of the particles of the binder is polygonal. An electrodeless discharge lamp lighting device, characterized in that a high frequency power of several kHz to several tens of MHz is supplied to the electrodeless discharge lamp according to any one of claims 1 to 6 to light the electrodeless discharge lamp. An illumination device comprising the electrodeless discharge lamp lighting device according to claim 7, and lighting the electrodeless discharge lamp according to any one of claims 1 to 6.

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