JP3167217B2 - Electrodeless discharge lamp lighting device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeless discharge lamp lighting apparatus for discharging and emitting a rare gas or metal vapor by a high-frequency electromagnetic field.

[0002]

2. Description of the Related Art Conventionally, an electrodeless discharge lamp lighting device for emitting an electrodeless discharge lamp by a high-frequency electromagnetic field has been known, and FIG. 5 shows an example of such a conventional example. Its configuration is several M from the high-frequency power supply device 100.
A high-frequency power (current) of Hz to several tens of MHz is output and supplied to an excitation coil 102 that generates a high-frequency electromagnetic field via an impedance matching device 101.
Numeral 2 is wound close to the electrodeless arc tube 103 in which a luminous substance such as a rare gas or metal vapor is sealed. The filling of the electrodeless arc tube 103 is excited by a high-frequency electromagnetic field generated by the excitation coil 102. The electrodeless arc tube 103 and the excitation coil 102 substantially act as a transformer for coupling high frequency power to the discharge plasma. That is, the excitation coil 102 acts as a primary coil, and the discharge plasma acts as a single-turn secondary coil. The high frequency current supplied to the excitation coil 102 creates a time-varying magnetic field, resulting in a completely closed annular electric field in the discharge plasma itself. Since an electric current flows by this electric field, an annular arc discharge is formed in the electrodeless arc tube 103.

However, in the electrodeless discharge lamp lighting device, the annular electric field generated by the excitation coil 102 is not strong enough to ionize the gaseous encapsulating material and easily start an arc discharge. A method for improving the startability of such an electrodeless lamp lighting device has already been proposed. For example, Japanese Patent Application Laid-Open No. 4-229550 discloses a starting auxiliary electrode (a conductive ring connected to one end of an excitation coil). ) Is used to capacitively couple a high voltage generated between both ends of the winding portion of the excitation coil to the electrodeless arc tube. A capacitive current flows between the starting auxiliary electrode and the excitation coil, and thus through the electrodeless arc tube, whereby the gaseous encapsulating material is ionized / excited and starts discharging.

[0004]

Generally, the probability of starting a discharge lamp including an electrodeless discharge lamp (the probability of starting discharge) depends on the initial electrons (such as an externally applied electric field) existing inside the arc tube immediately before starting. The electrons that have received the energy of the ion collide with neutral atoms and excited electrons and cause collision ionization, not the resulting electrons, but the electrons that are generated by the neutralization of neutral atoms and excited atoms by cosmic rays and visible light. And the probability that those electrons will ionize and excite the gaseous encapsulation material. That is, when the number of initial electrons is large or when the energy given to these electrons from the outside is large, the discharge lamp is easily started.

Accordingly, a high voltage is applied between the starting auxiliary electrode and the excitation coil or between a pair of starting auxiliary electrodes surrounding the electrodeless arc tube, as typified by the method described in JP-A-4-229550. The method of improving the startability by generating an electric field (voltage) higher than the electric field (voltage) required to maintain the discharge generated by the excitation coil during stable lighting through the electrodeless arc tube gives a larger energy to the initial electrons. That is, this is a method of improving the startability by increasing the probability that the initial electrons ionize and excite the gaseous sealing material.

[0006] However, the above-mentioned method has a drawback in the case where the number of initial electrons is extremely small, for example, the startability in darkness. That is, it is necessary to compensate for the small amount of the initial electrons by increasing the probability that the electrons ionize and excite the gaseous encapsulating material. Therefore, considerable energy must be given to the electrons. This can be achieved, for example, by increasing the number of turns of the excitation coil or by applying a considerably high voltage (electric field) to the electrodeless arc tube at the time of starting, but on the other hand, the device becomes large-sized and extensive. Not practical for commercial use.
Applying such a high electric field to the arc tube may cause early deterioration of the arc tube.

The present invention solves the above-mentioned problems, and provides a small and long-life electrodeless discharge lamp lighting device that can be started reliably at a relatively low voltage even when the number of initial electrons is small as in the dark. It is intended to be.

[0008]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides an electrodeless arc tube enclosing a luminous substance, and is arranged in proximity to the electrodeless arc tube to excite an arc discharge. An electrodeless discharge lamp lighting apparatus including a first excitation coil and a discharge tube having a pair of electrodes connected in series to the first excitation coil and enclosing a luminescent substance.

Further, the electrodes of the discharge tube are provided on the outer wall of the discharge tube. Furthermore, a thermal response that short-circuits a pair of electrodes of a discharge tube when thermal energy is received from an electrodeless arc tube, and opens a short circuit between the electrodes when the thermal energy received from the electrodeless arc tube is sufficiently reduced. Means are provided.

The discharge tube is an electrodeless discharge tube excited by a second excitation coil, and the first excitation coil and the second excitation coil are connected in series. Further, a thermal response means for short-circuiting both ends of the second excitation coil when receiving thermal energy from the electrodeless arc tube and opening the short circuit when the thermal energy received from the electrodeless arc tube is sufficiently reduced. It is provided.

[0011]

As described above, by providing a discharge tube having a pair of electrodes connected in series to the first excitation coil and enclosing a luminescent material, first, the gaseous luminescent material of the discharge tube is supplied between the electrodes. The discharge is started by being ionized by the high-frequency voltage (electric field) applied to the gas, and the light (photons) of this discharge ionizes or excites (photoionization / photoexcitation) the gaseous luminescent material inside the electrodeless arc tube. As a result, the number of electrons inside the electrodeless arc tube increases. Therefore, a sufficient (initial) electron can be secured even in a state where the number of initial electrons is extremely small, such as under darkness. At the same time as the discharge tube started discharging, the high-frequency current flows through the first excitation coil, and the ring-shaped electric field is generated in the electrodeless arc tube. As it is generated, it is accelerated by this annular electric field and repeatedly collides with the neutral or excited atoms of the gaseous encapsulating material, and eventually ionizes and excites them sufficiently.
Form an arc discharge.

As a result, even when the number of initial electrons is extremely small as in the dark, a sufficient number of initial electrons can be sufficiently secured. It is not necessary to increase the probability of excitation, so that startability can be improved without applying a high voltage to the electrodeless arc tube, and furthermore, early deterioration of the electrodeless arc tube due to application of a high electric field can be prevented.

Further, by providing the electrodes of the discharge tube on the outer wall of the discharge tube, blackening due to deterioration of the electrodes of the discharge tube can be prevented, so that the effect of improving startability over a long period of time can be obtained.
It is possible to extend the life of the lighting device.

Further, after the arc discharge has started in the electrodeless arc tube, when the electrodeless arc tube becomes sufficiently hot, a short circuit occurs between a pair of electrodes of the discharge tube, the lamp operation is terminated, and the electrodeless arc tube is terminated. If a thermal means for releasing the short circuit after the tube is cooled is provided, the electric power supplied to the discharge tube is not required during the lamp operation, so that the overall efficiency is improved. At the same time, the deterioration of the discharge tube can be prevented, so that the life of the lighting device can be extended.

[0015] Further, also in the case where the discharge tube is an electrodeless discharge tube, and the electrodeless discharge tube is excited and emits light by a second excitation coil connected in series to the first excitation coil, the same as described above. In addition, the number of electrons inside the electrodeless arc tube increases,
(Electrodeless) The effect of preventing blackening of the discharge tube is obtained, so that the startability of the lighting device can be improved and the life thereof can be prolonged.

Further, after the arc discharge has started in the electrodeless arc tube, when the electrodeless arc tube becomes sufficiently hot, the second
Short-circuit both ends of the excitation coil of
If the thermal means for releasing the short circuit after the electrodeless arc tube is cooled is provided, the electric power supplied to the second excitation coil (electrodeless discharge tube) during the lamp operation becomes unnecessary, so that
Overall efficiency also improves.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on one embodiment. First, an electrodeless discharge lamp lighting device according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a side view of a part of an electrodeless discharge lamp lighting device provided with a discharge tube having a pair of electrodes. In FIG. 1, 1 is a high-frequency power supply device, 2 is an excitation coil for exciting an electrodeless arc tube, 3 is a cylindrical electrodeless arc tube made of quartz, and 4 is a quartz tube having a pair of electrodes 5a and 5b. Discharge tube. The excitation coil 2 has a two-turn coil, is arranged so as to surround the electrodeless arc tube 3, and
And are connected in series. Electrodeless arc tube 3 and discharge tube 4
As shown in FIG. 1, the electrodeless arc tube 3 is filled with argon gas, mercury and a metal halide, and the discharge tube 4 is filled with argon gas and mercury. In the discharge tube 4, the distance between the electrodes 5 a and 5 b and the amounts of the argon gas and mercury as the filling material are appropriately selected so that the discharge is reliably started by the voltage applied from the high-frequency power supply device 1. . This is the electrode 5a,
This can be realized by shortening the distance between the electrodes 5b or reducing the pressure of the argon gas (rare gas) sealed in the discharge tube 4.

The operation of the above configuration will be described. Starting
At this time, the high-frequency voltage generated from the high-frequency power supply 1
And applied to the electrodes 5a and 5b, and the discharge tube 4 starts discharging.
I do. For a while after the start of discharge, mercury vapor inside the discharge tube 4
The pressure is also not high enough so that the spectrum of the emitted light
Is the resonance line of mercury at a wavelength of 253.7 nm (6^ThreeP₁From 6
¹S₀Transition, the energy is equivalent to 4.86 eV)
Dominant. Therefore, 4.86 eV from discharge tube 4
Photons are emitted, some of which are electrodeless
The light is emitted to the arc tube 3. In this way, the electrodeless
The photons radiated to the arc tube 3 emit gas inside the electrodeless arc tube 3.
Of course excites the mercury atom
The energy (4.96 eV) of the mercury atom
Separation energy Vi = 10.4 eV or less, no electrode
It is not possible to directly ionize mercury atoms inside the light tube 3
No, but in the case of mercury, ionization occurs due to cumulative ionization.
I can do it. The number of electrons generated by this cumulative ionization is
However, light having a wavelength of 253.7 nm is emitted from the discharge tube 4.
Continue to grow (some disappear due to recombination and diffusion)
However, the number of electrons inside the electrodeless arc tube 3 increases considerably.
In addition, the electrodeless arc tube 3 is placed in the dark.
However, sufficient (initial) electrons can be secured.

At the same time when the discharge tube 4 starts discharging, a high-frequency current flows through the excitation coil 2 and an annular electric field is generated in the electrodeless arc tube 3. The electrons resulting from the ionization of mercury atoms by photons, and the electrons originally present,
Accelerated by this annular electric field, it repeatedly collides with neutral atoms and excited atoms of the gaseous encapsulating material (mainly argon and mercury), and eventually sufficiently ionizes and excites them to form an arc discharge. At this time, the energy to be given to the electrons necessary to start the discharge is substantially large in the number of initial electrons.
Is it necessary to maintain arc discharge during stable lighting?
Or it doesn't have to be much more. In other words, since the initial electrons inside the electrodeless arc tube 3 can always be stably secured by the light irradiation from the discharge tube 4, an extremely high voltage is applied to the electrodeless arc tube 3 to increase the energy. Good startability can be obtained without applying (electric field) to those electrons.

As a result, even when the number of initial electrons is extremely small, such as in the dark, it is not necessary to increase the probability of starting the discharge of individual electrons because the number of electrons can be substantially sufficiently secured. Therefore, the startability can be improved without applying a high voltage to the electrodeless arc tube. At the same time, this also prevents early deterioration of the electrodeless arc tube 3 due to application of a high electric field.

In this embodiment, the lighting device in which the discharge tube 4 is formed integrally with the electrodeless arc tube 3 has been described as an example.
If the discharge tube 4 and the electrodeless arc tube 3 are positioned so that light from the discharge tube 4 is efficiently irradiated on the electrodeless arc tube 3, they may be separated from each other.

Next, an electrodeless discharge lamp lighting device according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a side view in which a part of an electrodeless discharge lamp lighting device including a discharge tube having a pair of electrodes provided on an outer wall is cut away. In FIG.
Reference numeral 6 denotes a discharge tube made of quartz having a pair of electrodes 7a and 7b on the outer wall and containing argon gas and mercury, and the other configuration is the same as that of the first embodiment. This discharge tube 6 is shown in FIG.
As shown in the figure, the electrodeless arc tube 3 is integrally formed.
In the discharge tube 6, the distance between the electrodes 7 a and 7 b and the amounts of the argon gas and mercury as the filling material are appropriately selected so that the discharge is reliably started by the voltage applied from the high frequency power supply device 1. Have been. This can be realized by shortening the distance between the electrodes 7a and 7b or reducing the pressure of the argon gas (rare gas) sealed in the discharge tube 6.

In the above configuration, at the time of starting, a high-frequency voltage generated from the high-frequency power supply 1 is applied to the electrodes 7a and 7b, and the discharge tube 6 starts discharging. For a while after the start of the discharge, a wavelength of 253.7 n due to mercury emission from the discharge tube 6.
m (photons having energy of 4.86 eV) is emitted, and a part of the light is irradiated to the electrodeless arc tube 3. As a result, as described in the first embodiment, since the initial number of electrons can be stably secured inside the electrodeless arc tube 3 by the cumulative ionization of mercury atoms, an extremely high voltage is applied to the electrodeless arc tube. Good startability can be obtained without applying a large energy (electric field) to the electrons by applying a voltage to the electrons.

In a discharge tube in which the electrodes are disposed inside the discharge space, the electrode material is scattered due to the high temperature of the ion of the filling material or the high temperature of the arc discharge. The emitted light flux is reduced. However, in the present embodiment, since the electrodes 7a and 7b of the discharge tube 6 are provided on the outer wall, the electrode material is sealed at both ends of the discharge tube, as seen in a general discharge lamp having electrodes in a discharge space. Is not scattered on the inner wall of the discharge tube to cause blackening. Therefore, due to long-term operation,
There is no fear that the irradiation light from the discharge tube 6 to the electrodeless arc tube 3 is reduced, in other words, the startability of the electrodeless arc tube 3 is reduced, and the life of the electrodeless discharge lamp lighting device can be extended.

Further, as in this embodiment, the electrodes are connected to the discharge tube 6.
Since the electrodes are not required to be sealed on the outer wall, the structure of the discharge tube 6 is simplified. For example, the discharge tube 6 is formed by using a thin tube used for exhausting the electrodeless light emitting tube 3. It is also possible to do.

Although the discharge tube 6 is formed integrally with the electrodeless arc tube 3 in this embodiment, the position where the discharge tube 6 is disposed, including the shape, can be efficiently irradiated with the electrodeless light emission tube. The position to be irradiated on the tube 3 is not limited to the position shown in the present embodiment.

Next, an electrodeless discharge lamp lighting device according to a third embodiment of the present invention will be described with reference to FIG. FIG. 3 shows a case where the electrodeless discharge lamp lighting device including the discharge tube provided with the pair of electrodes on the outer wall described in the second embodiment receives heat energy from the electrodeless arc tube in parallel with the pair of electrodes. When a short-circuit occurs between a pair of electrodes, and when the thermal energy received from the electrodeless arc tube decreases, as a thermal response means for releasing the short-circuit, for example, a thermal response means composed of bimetal is added. It is the side view which cut out some lamp lighting devices. In FIG. 3, 8 is a bimetal,
Other configurations are the same as those of the second embodiment.

From the electrodeless arc tube 3, as the discharge tube 6 starts discharging and shifts to a stable arc discharge, considerable heat is radiated to the surrounding space due to the high temperature of the arc discharge. When the bimetal 8 receives the thermal energy generated from the electrodeless arc tube 3, the electrodes 7a and 7b for supplying power to the discharge tube 6 are short-circuited, and conversely, the electrodeless arc tube 3 is turned off and the heat energy is reduced. It operates to open the short circuit when is reduced. Accordingly, the discharge tube 6 is turned on at the time of starting, but is not turned on during the stable lighting of the electrodeless arc tube 3 because the electrodes 7a and 7b are short-circuited.

As described in the second embodiment, the discharge tube 6
The light applied to the electrodeless arc tube 3 is used to increase the number of electrons inside the electrodeless arc tube 3 at the time of starting, so that the electrodeless arc tube 3 starts discharging and a stable arc discharge occurs. After that, the light emitted from the discharge tube 6 has no meaning. Therefore, even if the light is emitted from the discharge tube 6 only when the electrodeless arc tube 3 is started by the operation of the bimetal 8, there is no problem in improving the startability. Rather, it is not necessary to supply power to the discharge tube 6 during stable lighting, so that power consumption is reduced and the overall efficiency of the entire lighting device is improved.

Furthermore, the operation time of the discharge tube 6 is greatly shortened by the operation of the bimetal 8, so that the life of the discharge tube 6 is extended, and the life of the entire electrodeless discharge lamp lighting device is also extended. Is also obtained.

In this embodiment, when heat energy is received from the electrodeless arc tube 3, the electrodes 7a, 7b
An example has been described in which the thermal response means for short-circuiting between the (power supply terminals) and releasing the short-circuit when the thermal energy received from the electrodeless arc tube 3 is reduced is made of the bimetal 8. The response means may be of another type, such as one made of a shape memory alloy.

Further, in this embodiment, a discharge tube having a pair of electrodes provided on the outer wall has been described as an example. However, a discharge tube having another pair of electrodes, for example, as described in the first embodiment. Of course, even in a discharge tube in which a pair of electrodes are sealed in a discharge tube and the electrodes protrude into the discharge space, the effects described in the present embodiment can be obtained.

In the first to third embodiments, the discharge tube having a pair of electrodes has been described as an example. However, the number of electrodes of the discharge tube is not limited to one pair, and may be two pairs. It does not matter whether or not the discharge tube has an auxiliary pole for assisting the starting as seen in a general discharge lamp.

Next, an electrodeless discharge lamp lighting device according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 4 shows an electrodeless discharge lamp lighting device in which the discharge tube is an electrodeless discharge tube having no electrodes in the electrodeless discharge lamp lighting device provided with a pair of electrodes on the outer wall described in the second embodiment. It is the side view which cut out the part. In FIG. 4, reference numeral 9 denotes an electrodeless discharge tube in which argon gas and mercury are sealed, and 10 denotes an excitation coil for exciting and emitting light from the electrodeless discharge tube 9, and other configurations are the same as those of the second embodiment. It is. The excitation coil 10 has 5 turns, is wound so as to surround the electrodeless discharge tube 9, and is connected in series with the excitation coil 2 that excites and emits light from the electrodeless arc tube 3. The amount of the argon gas and mercury contained in the discharge tube 9 and the number of turns of the excitation coil 10 are set such that when the voltage is applied to the excitation coil 10 from the high-frequency power supply device 1, the electrodeless discharge tube 9 reliably starts discharging. Properly chosen. This can be realized by increasing the number of turns of the excitation coil 10 or reducing the pressure of the argon gas (rare gas) sealed in the electrodeless discharge tube 9.

In the above configuration, at the time of starting, a high-frequency voltage generated from the high-frequency power supply 1 is applied to the excitation coil 2 and the excitation coil 10, and the electrodeless discharge tube 9 is first discharged by the high electromagnetic field generated by the excitation coil 10. To start. From the discharge tube 9, a wavelength of 253.7 nm (4.
Light of a photon having an energy of 86 eV) is emitted, and a part of the light is emitted to the electrodeless arc tube 3. As a result, the first
Similarly to the case described in the first embodiment, since the initial number of electrons can be stably secured by the cumulative ionization of mercury atoms inside the electrodeless arc tube 3, an extremely high voltage is applied to the electrodeless arc tube 3. Good startability can be obtained without giving a large energy (electric field) to those electrons.

Since the discharge tube 9 has no electrode, there is no fear that the electrode material scatters on the inner wall of the discharge tube to cause blackening.
That is, the electrodeless arc tube 3 is discharged from the discharge tube 9 by long-term operation.
There is no decrease in irradiation light to the electrodeless arc tube 3, and the startability of the electrodeless arc tube 3 can be improved over a long period of time.

In addition to this, the advantage of using the electrodeless discharge tube 9 is that the configuration of the lighting device becomes very simple. That is, as compared with the case where the discharge tube emits light by providing the electrodes as described in the first embodiment or the second embodiment, in the case of the discharge tube having no electrode, the excitation coil 2 and the high frequency Since the discharge tube can emit light only by winding the conductor connecting to the power supply device 1, it is very advantageous in terms of manufacturing or cost of the lighting device.

Although the discharge tube 9 is formed integrally with the electrodeless arc tube 3 in this embodiment, the position where the discharge tube 9 is disposed, including the shape, is such that the irradiation light from the discharge tube 6 can efficiently emit the electrodeless light. The position to be irradiated on the tube 3 is not limited to the position shown in the present embodiment.

Further, in this embodiment, the number of turns of the excitation coil 10 is set to 5; however, the number of turns of the excitation coil is not limited to this as long as the number of turns at which the electrodeless discharge tube 9 reliably starts discharging. .

Further, in this embodiment, as in the case of the third embodiment, when heat energy is received from the electrodeless arc tube 3, both ends (terminals for supplying power) of the excitation coil 10 are short-circuited. Alternatively, a thermal response means for opening the short circuit when the thermal energy received from the electrodeless arc tube 3 decreases may be provided. In that case, the electrodeless discharge tube 9 is turned on during lighting.
Does not operate (emit light), so that the effect of extending the life of the electrodeless discharge tube 9 and improving the overall efficiency of the lighting device can be obtained.

In the first to fourth embodiments, the substances (argon gas, mercury) contained in the electrodeless arc tube 3 are sealed in the discharge tube 4, the discharge tube 6, and the electrodeless discharge tube 9. However, any other material can be used as the filling material as long as it generates light having a wavelength capable of photoionizing (including cumulative ionization) the gaseous filling material inside the electrodeless arc tube 3. It does not matter.

In the first to fourth embodiments, the cylindrical electrodeless arc tube 3 has been described as an example. However, the shape of the electrodeless arc tube 3 is not limited to this. Further, the substance to be sealed in the electrodeless arc tube 3 may be other than those described in the above embodiments.

Further, it is apparent that the shape and the number of turns of the excitation coil 2 for exciting the electrodeless arc tube 3 are not limited to those shown in the first to fourth embodiments.

In the first to fourth embodiments, the lighting device is configured to supply power from the high-frequency power supply device 1 directly to the excitation coil 3 (and the discharge tube for assisting start-up). Alternatively, power may be supplied via an impedance matching device. Although the present invention has been described with reference to a preferred embodiment, such description is not a limitation and, of course, various modifications are possible.

[0045]

As described above, according to the present invention, an electrodeless arc tube enclosing a luminous substance and a first excitation coil arranged close to the electrodeless arc tube for exciting arc discharge In the lighting device for an electrodeless discharge lamp including: a discharge tube having a pair of electrodes connected in series with the first excitation coil and enclosing a luminescent material, the discharge tube or the electrodeless discharge lamp at the time of starting. Utilizing irradiation light (photons) from the tube, the gaseous luminescent substance inside the electrodeless arc tube is ionized or excited (photoionization / photoexcitation), and the number of electrons inside the electrodeless arc tube is increased. Even in the state where the initial electrons are extremely small as shown below, sufficient (initial) electrons can be secured, the startability can be improved without applying a high voltage to the electrodeless arc tube, and the lighting device can be downsized. . further,
This prevents early deterioration of the electrodeless arc tube due to application of a high voltage (electric field), so that an economical lighting device can be supplied.

Also, by providing a pair of electrodes of the discharge tube on the outer wall of the discharge tube, or by connecting the discharge tube to an electrodeless discharge tube excited by a second excitation coil connected in series with the first excitation coil. By doing so, blackening due to electrode deterioration of the discharge tube can be prevented, so that the effect of improving the startability over a long period of time can be obtained, and the life of the lighting device can be extended.

Further, after the arc discharge has started in the electrodeless arc tube, when the electrodeless arc tube becomes sufficiently hot, a short circuit is caused between the pair of electrodes of the discharge tube or both ends of the second excitation coil to cause a short circuit. If the thermal means for releasing the short circuit after the operation is completed and the electrodeless arc tube cools is provided, the power supply to the discharge tube during the lamp operation becomes unnecessary, so that the overall lighting device The efficiency is improved, and the lighting device can be downsized. At the same time, since the deterioration of the discharge tube can be prevented, the life of the lighting device can be extended, and therefore, a highly practical lighting device can be provided.

[Brief description of the drawings]

FIG. 1 is a side view of a part of an electrodeless discharge lamp lighting device according to a first embodiment of the present invention.

FIG. 2 is a side view of a part of the electrodeless discharge lamp lighting device according to a second embodiment of the present invention.

FIG. 3 is a side view of a part of the electrodeless discharge lamp lighting device according to a third embodiment of the present invention.

FIG. 4 is a side view of a part of the electrodeless discharge lamp lighting device according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing a conventional electrodeless discharge lamp lighting device.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 high frequency power supply 2 excitation coil 3 electrodeless arc tube 4 discharge tube 6 discharge tube 8 bimetal 9 electrodeless discharge tube 10 excitation coil

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takuyuki Kamiya 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-1-243304 (JP, A) JP-A-6 −13051 (JP, A) Japanese Utility Model Application Hei 4-98298 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 65/00-65/04

Claims (6)

(57) [Claims] 1. An electrodeless arc tube enclosing a luminescent substance, and a first excitation coil disposed in close proximity to the electrodeless arc tube to excite an arc discharge in the electrodeless arc tube. An electrode discharge lamp lighting device, comprising: a discharge tube filled with a luminescent substance, wherein the discharge tube has a pair of electrodes, and the electrodes of the discharge tube are connected in series with the excitation coil. An electrodeless discharge lamp lighting device characterized by the above-mentioned. 2. An electrodeless discharge lamp lighting device according to claim 1, wherein an electrode of the discharge tube is provided on an outer wall of the discharge tube. 3. When the thermal energy is received from the electrodeless arc tube, a short circuit occurs between the pair of electrodes of the discharge tube, and when the thermal energy received from the electrodeless arc tube is sufficiently reduced, the short circuit occurs between the pair of electrodes. 3. The electrodeless discharge lamp lighting device according to claim 1, further comprising a thermal response means for opening a short circuit. 4. The discharge tube is an electrodeless discharge tube, wherein the electrodeless discharge tube is excited by a second excitation coil disposed near the electrodeless discharge tube, and wherein the second excitation coil is excited by a second excitation coil. The lighting device for an electrodeless discharge lamp according to claim 1, wherein the lighting device is connected in series with one excitation coil. 5. When the thermal energy is received from the electrodeless arc tube, both ends of the second excitation coil are short-circuited, and when the thermal energy received from the electrodeless arc tube is sufficiently reduced, the second excitation coil is shorted. 5. The lighting device for an electrodeless discharge lamp according to claim 4, further comprising a thermal response means for opening a short circuit at both ends of the discharge lamp. 6. The lighting device for an electrodeless discharge lamp according to claim 3, wherein the thermal response means is made of a bimetal.