JP3196649B2 - Electrodeless high pressure discharge lamp - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention fills a light-transmissive bulb with a metal halide having continuous light emission by molecular light emission and emits an arc discharge to achieve extremely excellent color rendering and high efficiency. The present invention relates to a realized electrodeless high-pressure discharge lamp.

[0002]

2. Description of the Related Art In recent years, high-pressure discharge lamps, particularly metal halide lamps, have high efficiency and high color rendering properties. Applications to such applications are underway. In addition, due to its high color rendering properties, the development of sports lighting compatible with HDTV broadcasting and facility lighting of museums and art galleries has been promoted. However, since metal halide lamps contain mercury as a filler in a large amount of several tens of mg / cc per inner volume, mercury-free is strongly desired from the viewpoint of environmental protection.

[0003] The electrodeless discharge lamp device has the advantage that, compared to the electrode arc discharge lamp device, it is easy to couple electromagnetic energy to the filling and it is easy to omit mercury from the filling for discharge luminescence. Have. Further, since no electrodes are provided inside the discharge space, blackening of the bulb inner wall due to electrode evaporation does not occur. This can significantly improve the lamp life.

[0004] The mercury-free filling of a conventional high-pressure discharge lamp will now be described with some examples. JP-A-3-
In the electrodeless discharge lamp disclosed in Japanese Patent No. 152852, xenon is used as a discharge gas and L is used as a luminescent material.
White light is obtained by enclosing iI, NaI, TlI, InI, and the like, and combining monochromatic emission line spectra emitted from these luminescent materials. Here, means for inductively coupling RF energy is exemplified as the discharge excitation means.

In the high power lamp disclosed in Japanese Patent Application Laid-Open No. Hei 6-132018, S ₂ , S
filled with e _2, etc., by continuous spectrum by molecular emission, to obtain white light greenish. Here, a discharge excitation unit using microwave energy is illustrated.

In the present invention, the molecular luminescence of a metal halide such as indium iodide is utilized. An invention relating to an electroded metal halide lamp having a similar filling is disclosed in U.S. Pat. No. 3,259,777. Here, in order to discharge a metal halide such as indium iodide at a high pressure, the lamp operates at a high input electric energy such that the electrode approaches the melting point.

[0007]

SUMMARY OF THE INVENTION However, Japanese Patent Application Laid-Open
In the electrodeless discharge lamp of JP-A-152852, the color rendering point is lowered when the efficiency is increased by increasing the components of Na and Tl which emit light in a portion having high luminous efficiency, and conversely, when the color rendering is to be enhanced. There was a problem that the efficiency was low. It has also been pointed out as a problem that indium and thallium iodides generate a continuous spectrum when the pressure is increased and the emission line spectrum is reduced to cause a color shift. In addition, the light characteristics composed of a combination of bright line spectra as disclosed in JP-A-3-152852 are poor in color reproducibility, and it is difficult to obtain a sufficiently high color rendering property.

In the high-power lamp disclosed in Japanese Patent Application Laid-Open No. 6-132018, the chromaticity is always located at a position shifted from the blackbody locus considerably to green, even if the kind of gas and the condition of the filling are changed. White light cannot be obtained. JP-A-6-1
As a method of improving the color characteristics of the high power lamp disclosed in Japanese Patent No. 32018, a method of adding a metal compound as a luminescent substance to change the chromaticity by adding a bright line spectrum or the like can be considered.

However, many metal sulfides are relatively stable and have a low vapor pressure, and the types of metals that can be added and emit light are limited. Therefore, there is a problem that the degree of freedom in light color design is low and it is difficult to achieve high color rendering. Further, when an inclusion is added or the spectral characteristic of the emission spectrum is changed by a color temperature conversion filter or the like, the spectral radiant intensity of a portion having low visibility other than green increases, so that a decrease in efficiency is inevitable.

In US Pat. No. 3,259,777, since the electrodes are operated with mercury-free, the electrodes are subjected to a considerable load of operating the lamp near the melting point of the electrodes. Therefore, in the lamp having such a design, the inner wall of the bulb is suddenly blackened due to the evaporation of the electrode, and it is inevitable that the life characteristic is remarkably deteriorated.

The present invention solves the above-mentioned problems of the conventional filler as a discharge luminous substance and the discharge excitation means.
By using the continuous spectrum of molecular luminescence at high pressure of a metal halide that emits a continuous spectrum by molecular luminescence, a luminescent material that does not contain mercury as a filler and has both high efficiency and high color rendering properties It is an object of the present invention to provide an electrodeless high-pressure discharge lamp.

[0012]

In order to achieve this object, an electrodeless high-pressure discharge lamp according to the present invention comprises an indium halide or gallium in a light-transmitting bulb having no electrodes exposed inside . Halide or
Is at least one of thallium halides or
Is a metal halide selected from the group consisting of these mixtures
And a filler containing a rare gas.
The amount of the genide charged is determined by the volume of the discharge space of the permeable bulb.
More than about 0.5 × 10 ^-6 mol per 1 cc product
It has a configuration that does not include it.

The discharge is started with the rare gas, and the metal compound starts the discharge with the increase of the vapor pressure of the rare gas. After that, by injecting strong electric energy into the metal compound intensively, it has an extremely excellent color rendering property and a highly efficient light characteristic with a strong continuous emission spectrum by molecular emission, and mercury as a filler. An electrodeless high-pressure discharge lamp that is environmentally safe because it does not contain it can be obtained.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 Hereinafter, an embodiment of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 shows that 2.88 × 10 ⁻⁶ mol / cc of indium iodide (InI) and 5 torr of argon gas were placed inside an electrodeless discharge bulb made of spherical quartz glass having an inner diameter of 3.8 cm. 3 is an emission spectrum when the filled lamp is discharged and emitted with a microwave energy input of 800 W in the microwave electrodeless discharge lamp device shown in FIG. 2. However, the volume cc used in the present invention
Is the internal volume of the bulb that is effective for discharging the lamp. Further, the emission spectrum shown in FIG. 1 is obtained by integrating the radiation intensity at every 5 nm.

A conventional structure of a microwave electrodeless discharge device for obtaining radiation light according to the present invention as shown in FIG. 1 will be described with reference to FIG. The configuration of the microwave electrodeless discharge device is the same as that of the high power lamp disclosed in Japanese Patent Application Laid-Open No. Hei 6-132018.

In FIG. 2, a valve 21 has a filling 22 such as indium iodide or argon gas.
It is made of quartz glass. The bulb 21 is supported in the microwave cavity 24 by a support rod 23 made of a dielectric material. The support rod 23 may be connected so that the axis of the support rod coincides with the rotation axis of the motor. At that time, the valve 21 is driven by
It rotates at a rotation speed of 3600 rpm. In the embodiment whose emission spectrum is shown in FIG.
Light was emitted while rotating at rpm.

As a result, the temperature of the bulb 21 can be equalized and the discharge plasma can be stabilized. The microwave energy generated by the magnetron 27 is supplied to the power supply port 25 of the microwave cavity 24 through the waveguide 26. The supplied microwave energy excites the filler 22 inside the bulb 21 to generate light in a plasma state. By making the microwave cavity 24 a conductive mesh or the like configured to substantially not transmit microwave energy and to substantially transmit light generated by the bulb 21, the generated light is It is taken out of the wave cavity 24.

According to the present embodiment as shown in FIG.
It is possible to obtain a continuous spectrum light emission over the entire visible region by indium iodide. In this embodiment, the average color rendering index Ra is 96, and the lamp efficiency is about 100 lm / W.
Met. The special color rendering index R9 representing a bright red appearance, which is generally difficult to show a high value, was 77. As described above, the lamp according to the present embodiment exhibits extremely excellent color rendering properties and extremely excellent luminous efficiency. It is widely known that the emission spectrum of indium iodide under high-pressure discharge is that of indium element.
It is a bright line spectrum of the blue part of 10 nm and 451 nm.

This emission line spectrum is generally used to increase the blue light emission intensity of a metal halide lamp. However, in the embodiment of the present invention, the emission line spectrum of the indium element is extremely weakened, and a continuous spectrum of molecular emission appears over the entire visible range. This makes it possible to obtain a highly efficient white light source having extremely excellent color rendering properties.

Another advantage of the electrodeless high-pressure discharge lamp of the present invention is that it is possible to use a single filling as a main discharge source. A typical metal halide lamp contains several metals and metal halides as fillers to obtain white light. The partial pressure of the added metal is determined by the amount of filling inside the lamp and the temperature at the coldest point of the bulb. However, both the amount of packing and the temperature of the coldest point,
The parameters are changed due to factors such as manufacturing tolerances and aging. This causes changes in optical characteristics such as the total luminous flux and chromaticity of the emitted light.

For example, in a metal halide lamp made of a filler such as Hg + InI + TlI + NaI, a white color is obtained by combining the blue of In, the green of Tl element, and the yellow of Na element. affect. However,
It has been pointed out that metals widely used in metal halide lamps, such as Na, Sc, and Dy, react with quartz glass, which is the envelope of the lamp, during operation and reduce the absolute amount thereof. This causes a color shift of the lamp and a decrease in light output as a change with time.

On the other hand, since the lamp of the present invention can be constituted by a single metal halide, the influence on the color characteristics due to manufacturing tolerance and aging can be greatly reduced.

Table 1 shows some examples of light emission characteristics by adding a bulb in which the amount of indium iodide is changed. All the bulbs shown here were rotated at 3600 rpm in the microwave electrodeless discharge device shown in FIG.
This is the case when lighting is performed with the input electric energy of 0 W.

[0025]

[Table 1]

As the amount of indium iodide is increased, the correlated color temperature tends to decrease. This is because the peak wavelength of the continuous spectrum of molecular emission of indium iodide shifts to a longer wavelength as the amount of encapsulated material increases. This is considered to be because the internuclear distance of the indium iodide molecule becomes smaller and the energy difference of the transition becomes smaller as the molecular weight of the indium iodide during operation increases. However, the amount of this color shift is not sensitive to small changes that would be problematic for the previously mentioned manufacturing tolerances.

On the contrary, this characteristic gives a degree of freedom in designing the correlated color temperature. Therefore, it is possible to provide a lamp having an appropriate correlated color temperature for various application fields.
For example, as a light source for a liquid crystal video projector, a lamp having a higher correlated color temperature of 7000 K or higher is required in order to increase the blue color. The electrodeless high-pressure discharge lamp of the present invention can meet such demands by changing the amount of indium iodide charged.

FIGS. 3 and 4 show the effect of input energy on the light characteristics of the lamp. FIG. 3 and FIG.
Inside an electrodeless discharge bulb made of spherical quartz glass having an inner diameter of 3.8 cm, 50 torr of argon gas, 1.44 × 10 ⁻⁶ mol / cc of indium iodide and 2.88 × of indium iodide were used.
2 shows the changes in efficiency and average color rendering index when two kinds of lamps filled and filled with 10 ^-6 mol / cc are changed in the microwave electrodeless discharge lamp device shown in FIG. It is.

The bulb emitted light while rotating at 3600 rpm by a motor in the same manner as in the above embodiment. The luminous efficiency of the lamp increases as the input electrical energy increases. There is a saturation point in this increase in luminous efficiency. This saturation point increases as the amount of packing increases.
At higher input electrical energy.

Further, from the change of the average color rendering index Ra shown in FIG. 4, when the input electric energy density is about 7 W / cc or more, Ra takes a value of 80 or more which is sufficient for use in general lighting. The input electric energy density is about 15W /
With cc, more preferably about 20 W / cc or more, it is possible to achieve both higher color rendering properties and high luminous efficiency.

At low input electrical energy densities, not enough indium iodide has yet evaporated into the bulb, which is one factor that reduces efficiency and color rendering. In the low energy region, since the pressure of the plasma is still low, the emission line spectrum of the indium element alone emits light predominantly. Therefore, sufficient efficiency and color rendering properties cannot be obtained.

FIG. 5 shows changes in efficiency and average color rendering index Ra with respect to changes in the amount of indium iodide filled and filled. The shape of the bulb and the lighting conditions are the same as those in FIG. 3 and FIG. 4, and the input energy density is that at 27.9 W / cc. A solid line indicates a change in efficiency with respect to a change in the filling amount, and a dotted line indicates a change in the normal color rendering index. When the filling amount is about 0.5 × 10 ⁻⁶ mol per cc or more, the average color rendering index exceeds 80, which is a sufficient value for use of general lighting. When the filling amount is about 3.0 × 10 ⁻⁶ mol or more, the efficiency is 90 lm / W or more, and the average color rendering index is 95%.
The above high values can be compatible. Therefore, in order to use it in the field of general lighting, it is desirable to fill indium iodide in this region. However, the filling amount is about 6.
If it exceeds 0 × 10 ^-6 mol, the average color rendering index will be 90 or less. Therefore, it is not desirable to fill indium iodide in a large amount.

In this embodiment, the case where indium iodide is used as the filler is described. However, similar characteristics are obtained when indium bromide is used as the filler.

In this embodiment, quartz glass is used as the light transmitting material of the bulb 21 shown in FIG. 2, but the constituent material of the bulb is not limited to this. For example, if a light-transmitting ceramic material of alumina is used as a constituent material of the valve, the heat resistance of the valve can be increased. Thereby, the valve has better high heat resistance and high pressure resistance, and can operate under higher input electric energy. Further, it is easy to omit the mechanism for rotating the bulb described above, and it is possible to improve the system efficiency and the manufacturing cost of the electrodeless high-pressure discharge lamp device.

(Embodiment 2) Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows that gallium iodide (GaI ₃ ) 2.22 × 10 ⁻⁶ mol / cc and argon gas 2 torr were placed inside an electrodeless discharge bulb made of spherical quartz glass having an inner diameter of 2.8 cm. FIG. 5 is an emission spectrum when the lamp filled with is filled and discharged with a microwave energy input of 550 W in the microwave electrodeless discharge lamp device shown in FIG. 2 as in the first embodiment. However, a mechanism for rotating the valve is not used in the present embodiment. In addition, the emission spectrum shown in FIG. 5 is obtained by integrating the radiation intensity at every 5 nm, as in FIG.

Here, 403 nm of gallium element and 4 g
In addition to the 17 nm emission line spectrum, a continuous spectrum was obtained by molecular emission in which the emission line spectra of sodium, lithium and potassium contained as impurities were added.
The characteristics of the lamp of the present embodiment are as follows.
3lm / W, average color rendering index Ra was 96, and correlated color temperature was 6,920K.

The continuous spectrum of the gallium halide has a peak at a shorter wavelength than the continuous spectrum of the indium halide, so that the correlated color temperature increases. This property is suitable for a field requiring a high correlated color temperature lamp such as a light source for liquid crystal video projection. Further, by filling with an indium halide, it can be used for changing characteristics such as correlated color temperature.

With respect to the electrodeless lamp filled with gallium iodide and gallium bromide, when the filling amount is changed, when the input electric energy is changed, the change in the optical characteristics is as follows.
This is the same as the case of the indium halide of the first embodiment.

In the above embodiment, halides of indium and gallium have been described as metal compounds which emit a continuous spectrum by molecular emission. However, halides of aluminum and thallium are similarly used to emit a continuous spectrum by molecular emission. These can be used as a filling metal compound.

(Embodiment 3) Hereinafter, a third embodiment of the present invention will be described with reference to the drawings.

FIG. 7 shows that an electrodeless discharge bulb made of spherical quartz glass having an inner diameter of 2.8 cm was filled with 40 mg of zinc,
FIG. 3 is an emission spectrum when discharge and emission are performed with a microwave energy input of 300 W in a microwave electrodeless discharge lamp device shown in FIG. 2 in which TlI (8 mg) and argon gas (2 torr) are filled.

According to the present embodiment, as shown in FIG.
Light emission can be obtained in which a continuous spectrum over the entire visible region is added to the 535 nm emission line spectrum of Tl. Filling and enclosing only TlI and argon gas
When only a 35-nm emission line spectrum is emitted, the color rendering index Ra is 15 or less, which is not suitable for general illumination. However, in the present embodiment, the color rendering index Ra is 84, which is significantly improved.

As shown in (Table 2), compared with the case where continuous light emission was obtained by high-pressure discharge without zinc,
The luminous efficiency is twice or more. This is because there is no significant change in the intensity of the 535-nm emission line spectrum, but the light emission in the continuous spectrum part is greatly increased. This is considered to be because the pressure inside the valve has been increased by zinc, and it can be seen that higher efficiency can be obtained by adding zinc.

(Embodiment 4) Hereinafter, a fourth embodiment of the present invention will be described with reference to the drawings.

FIG. 8 shows a spherical quartz glass electrodeless discharge bulb having an inner diameter of 2.8 cm inside which 20 mg of zinc, InI6
FIG. 3 is an emission spectrum when discharge and light emission are performed with an energy input of 300 W in the microwave electrodeless discharge lamp device shown in FIG. Here In
The emission spectra were obtained by adding a continuous spectrum over the entire visible range to the emission line spectra at 411 nm and 450 nm. In this embodiment, the luminous efficiency is slightly lower than that of the third embodiment because the wavelength of the bright line spectrum deviates from the portion where the luminous efficiency is high, but the color rendering index Ra can be 87.

(Embodiment 5) A fifth embodiment of the present invention will be described below with reference to the drawings.

FIG. 9 shows a spherical quartz glass electrodeless discharge bulb having an inner diameter of 2.8 cm, in which 20 mg of zinc, InI1
0 mg, TlI 5 mg, NaI 1 mg, argon gas 2
In the microwave electrodeless discharge lamp device shown in FIG.
It is an emission spectrum when discharge light emission is performed at an input of 250 W. In the present embodiment, light emission was obtained in which a continuous spectrum was added to the emission line spectra of In, Tl, and Na. The color rendering index Ra is 85, and white light emission with chromaticity (x, y) of (0.321, 0.336) can be obtained.

Discharge luminescence characteristics under the above embodiment and other filling and filling conditions according to the present invention (Table 2)
Is shown in comparison with.

[0050]

[Table 2]

By using zinc as the filler, a desired operating pressure suitable for light emission of the metal halide can be obtained without using mercury. Is not limited to the above embodiment. For example, by adding LiI or the like and using a 670 nm emission line spectrum, it is possible to further improve the color rendering properties.

It is clear that in all embodiments, the harmful UV radiation below 350 nm, which is a problem in mercury-containing high-pressure discharge lamps, is also greatly suppressed.
Much of the UV radiation from conventional metal halide lamps is due to the mercury emission spectrum, which is an effect that appears because mercury is not included as a fill.

This is an important advantage for improving safety to the human body with general lighting and for protecting exhibits in museums and museums.

The electrodeless high-pressure discharge lamp according to the present invention shown in the first to fifth embodiments is disclosed in
The same effect can be obtained also in an electrodeless discharge lamp device which excites a filler by RF inductive coupling as exemplified in JP-A-152852.

[0055]

As described above, according to the present invention, the indium halide or the gallium
Of halides or thallium halides
At least one, or a mixture of these
Containing metal halide and rare gas selected from
And the filling amount of the metal halide is
0.5 × 10 / cc of discharge space volume
^-6 mol or more, by providing a configuration that does not contain mercury, has a strong continuous emission spectrum due to molecular emission,
An excellent electrodeless high-pressure discharge lamp and an electrodeless high-pressure discharge lamp device capable of obtaining extremely excellent color rendering properties and highly efficient light characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is an emission spectrum diagram of an electrodeless discharge lamp filled with indium iodide and argon according to a first embodiment of the present invention.

FIG. 2 is a schematic diagram of a microwave electrodeless discharge lamp device according to the present invention.

FIG. 3 is a diagram showing a correlation between energy input and efficiency of an electrodeless discharge lamp filled with indium iodide and argon according to the first embodiment of the present invention.

FIG. 4 is a diagram showing a correlation between an energy input and an average color rendering index of an electrodeless discharge lamp in which indium iodide and argon are sealed according to the first embodiment of the present invention.

FIG. 5 is a diagram showing the correlation between the filling amount of indium iodide and the average color rendering index of the electrodeless discharge lamp in which indium iodide and argon are sealed according to the first embodiment of the present invention.

FIG. 6 is an emission spectrum diagram of an electrodeless discharge lamp filled with gallium iodide and argon according to a second embodiment of the present invention.

FIG. 7 shows zinc and Tl according to a third embodiment of the present invention.
Emission spectrum of electrodeless discharge lamp filled with I and argon

FIG. 8 shows zinc and In according to a fourth embodiment of the present invention.
Emission spectrum of electrodeless discharge lamp filled with I and argon

FIG. 9 shows zinc and In according to a fifth embodiment of the present invention.
Emission spectrum of an electrodeless discharge lamp filled with I, TlI, NaI, and argon

[Explanation of symbols]

 21 Valve 22 Filling 24 Microwave cavity 27 Magnetron

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-49158 (JP, A) JP-A-6-13052 (JP, A) JP-A-3-152852 (JP, A) JP-A-63-1982 291351 (JP, A) Table 10-507868 (JP, A) US Patent 3,259,777 (US, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01J 65/00-65/04 H05B 41/42

Claims (11)

(57) [Claims] 1. A light-transmitting bulb for confining a discharge, and at least one of indium halide, gallium halide, or thallium halide , or a mixture thereof, inside the light-transmitting bulb. It is selected from the group and a filling containing Rukin genus halide and a rare gas, filling of the metal halide
Volume per cc of discharge space volume of the permeable bulb.
An electrodeless high-pressure discharge lamp characterized in that it is about 0.5 × 10 ^-6 mol or more and does not contain mercury . 2. A light-transmitting bulb for confining a discharge,
At least indium halogenation inside the light-transmitting bulb
And a filler containing a rare gas.
The filling amount of the halide is controlled by the discharge space of the permeable bulb.
Approximately 0.5 × 10 per 1 cc volume ^-6 Mol or more
An electrodeless high-pressure discharge lamp, characterized in that: 3. The method of claim 1, wherein the halogen of the metal halide is iodine,
3. An electrodeless high-pressure discharge lamp according to claim 1, wherein said electrodeless high-pressure discharge lamp is made of bromine, chlorine or a mixture thereof. 4. An electric energy is applied to said filling material to
A discharge exciting means for initiating and sustaining a spark discharge, wherein the electric energy applied by the discharge exciting means is at least about 7 W per cc of volume of the discharge space of the transparent bulb. 1 or claim
2. The electrodeless high-pressure discharge lamp according to 2. 5. An electric energy is applied to said filling material,
A discharge exciting means for initiating and sustaining a spark discharge, wherein the electric energy applied by the discharge exciting means is at least about 15 W per cc of volume of the discharge space of the transparent bulb. 1 or billing
Item 2. An electrodeless high-pressure discharge lamp according to Item 2 . 6. The electrodeless high pressure discharge lamp according to claim 4 , wherein said rare gas is selected from the group consisting of Ar, Kr, Xe and a mixture thereof. 7. An electrodeless high pressure discharge lamp according to claim 6, wherein the pressure during the operation of the filling is at least 1 atm. 8. The electrodeless high-pressure discharge lamp according to claim 4 , wherein said light-transmitting bulb is made of quartz glass. 9. The electrodeless high-pressure discharge lamp according to claim 4 , wherein said light-transmitting bulb is made of ceramic. 10. The electrodeless high-pressure discharge lamp according to claim 4 , wherein microwave energy is coupled to said filling material as said discharge excitation means. Electrodeless high pressure discharge lamp device. 11. The electrodeless high-pressure discharge lamp according to claim 4 , wherein RF energy is inductively coupled to said filling material as said discharge excitation means. Electrodeless high pressure discharge lamp device.