JP3385010B2 - Mercury-free high-intensity discharge lamp lighting device and mercury-free metal halide lamp - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mercury-free high-intensity discharge lamp lighting device in which a light-emitting substance does not contain mercury, and a mercury-free metal halide lamp.

[0002]

2. Description of the Related Art In recent years, high-intensity discharge lamps have been used for general lighting, projectors, and automobile headlights. High-intensity discharge lamps have the advantages of higher efficiency, lower power consumption, and higher brightness than halogen lamps, and are therefore expected to become popular. A metal halide lamp is one of the high-intensity discharge lamps that are expected to become popular. A cross-sectional structure of the metal halide lamp is shown in FIG.

The metal halide lamp shown in FIG. 1 has an arc tube 1 made of quartz glass, and sealing parts 2 located at both ends of the arc tube 1 for hermetically sealing the interior of the arc tube 1.
A pair of electrodes 3 made of tungsten are arranged in the arc tube 1, and a luminous substance 6 containing mercury and a metal halide and a rare gas (not shown) are enclosed in the arc tube 1. ing. The pair of electrodes 3 in the arc tube 1 is connected to one end of a molybdenum foil 4,
Are sealed by the sealing portion 2. Molybdenum foil 4
The lead wire 5 is connected to the other end of the. Lead wire 5
Will be electrically connected to a lighting circuit (not shown).

The light emitting principle of the metal halide lamp shown in FIG. 1 will be briefly described. When a voltage is applied from the lighting circuit to the lead wire 5 to turn on the lamp, part or all of the metal halide (6) evaporates, and then arc discharge generated between the pair of electrodes 3 causes metal atom And halogen atoms are dissociated, and metal atoms are excited and emit light. In the vicinity of the tube wall of the arc tube 1, the dissociated metal atom is recombined with the halogen atom to return to the metal halide. By repeating this cycle phenomenon, the lamp lights up stably. In general, a metal halide has a vapor pressure lower than that of mercury, but is easily excited and has a property of easily emitting light. Therefore, in a metal halide lamp, the emission of an added metal tends to be stronger than the emission of mercury. is there. Therefore, mercury mainly plays a role as a buffer gas for determining the voltage inside the arc tube 1. The rare gas in the arc tube 1 plays a role as a starting gas.

In a general high-intensity discharge lamp including the metal halide lamp shown in FIG. 1, when a straight line connecting a pair of electrodes 3 is lit horizontally (hereinafter referred to as "horizontal lighting"), the arc tube is lit. Due to the convection of vapor inside the arc 1, the arc 7 generated between the pair of electrodes 3 bends upward as shown in FIG. If the arc 7 sticks to the tube wall of the arc tube 1 with a large degree of bending, the temperature of the arc tube upper portion 1a locally rises, so that devitrification or deformation of the arc tube upper portion 1a begins relatively early. As a result, the life characteristics of the lamp are deteriorated.

Several proposals have been made in order to suppress the curvature of the arc 7 and improve the life characteristics of the lamp.
As one example, there is a technique of applying a magnetic field to a metal halide lamp to suppress arc bending, which is disclosed in, for example, Japanese Patent Laid-Open No. 55-86062 and Japanese Patent Laid-Open No. 9-161725. In the technique disclosed in Japanese Patent Laid-Open No. 55-86062, a strong rare earth magnet is arranged above the arc tube 1 in a metal halide lamp containing mercury in the arc tube 1, and the repulsive force between the magnet and the arc 7 is arranged. (Lorentz force) is used to push down the arc 7,
Thereby, the curvature of the arc 7 is suppressed. On the other hand, the technique disclosed in Japanese Patent Application Laid-Open No. 9-161725 uses an electromagnet as a means for applying a magnetic field instead of the rare earth magnet. A technique for changing the arc position by using an electromagnet is disclosed in JP-A-11-31.
2495, JP-A-11-317103, JP-A-2
Some are disclosed in Japanese Patent Publication No. 000-12251.

[0007]

Recently, environmental problems have been emphasized, and a metal halide lamp containing no mercury is desired in consideration of the global environment at the time of disposal. Therefore, the inventor of the present application comparatively studied a mercury-free metal halide lamp and a mercury-free metal halide lamp in order to develop a mercury-free mercury-free metal halide lamp.

As a result of examination, it has been found that the mercury-free metal halide lamp has considerably different characteristics as compared with a metal halide lamp containing mercury. For example, even in a mercury-free metal halide lamp, arc curvature can be suppressed by applying a magnetic field to the mercury-free metal halide lamp, but the method of applying the magnetic field and the principle of suppressing curvature are different from those containing mercury. there were. Further, it was observed that the arc 7 itself became unstable depending on the strength of the magnetic field and the arc 7 fluctuated. This fluctuation of the arc 7 causes flicker when used as a lamp, which is not preferable.

The present invention has been made in view of the above points, and its main object is to provide a mercury-free high-intensity discharge lamp lighting device and a mercury-free metal halide lamp in which fluctuation of an arc is suppressed to prevent flicker. Especially.

[0010]

A mercury-free high-intensity discharge lamp lighting device according to the present invention has a light-emitting tube in which a pair of electrodes are arranged in a tube in which a light-emitting substance is sealed, and a high-intensity discharge for horizontal lighting is provided. A lamp and a lighting circuit including an alternating current generating means for supplying an alternating current to the pair of electrodes, wherein the arc tube does not contain mercury as the luminescent material, and the tip of the pair of electrodes is Further comprising magnetic field applying means for applying a magnetic field containing a component substantially perpendicular to the straight line connecting the lines, the magnetic field applied to the center between the tips of the pair of electrodes is B (mT), and The distance between the tips is d (mm), the tube pressure of the arc tube during steady lighting is P ₀ (MPa), and the power consumed during steady lighting is W
(W) and the stable frequency during steady lighting is f (Hz), the relationship of 0 <(100BW / f) −P ₀ d <100 is satisfied.

Another mercury-free high-intensity discharge lamp lighting device according to the present invention has a high-intensity discharge lamp that is horizontally lit, having a light-emitting tube in which a pair of electrodes are arranged in a tube in which a light-emitting substance is sealed. And a lighting circuit including an alternating current generating means for supplying an alternating current to a pair of electrodes, in the arc tube,
A magnetic field applying unit that does not contain mercury as the luminescent substance, contains at least a rare gas, and applies a magnetic field containing a component substantially perpendicular to a straight line connecting the tips of the pair of electrodes, Furthermore, the magnetic field applied to the center between the tips of the pair of electrodes is B (mT), the distance between the tips of the pair of electrodes is d (mm), and the rare gas is sealed at 20 ° C. When the pressure is P (MPa), the power consumed during steady lighting is W (W), and the stable frequency during steady lighting is f (Hz), 0 <(10BW / f)-
It is characterized in that the relationship of Pd <10 is satisfied.

The enclosed pressure P is 0.1 (MPa) <P
It is preferably in the range of <2.5 (MPa).

The enclosed pressure P and the distance d are P ·
It is preferable to satisfy the relationship of d <8.

The enclosed pressure P and the distance d are Pd
It is more preferable to satisfy the relationship of ≦ 4.6.

The lighting frequency f during the steady lighting is 40
It is preferable that (Hz) <f.

The magnetic field B is preferably in the range of B <500 (mT).

The distance d between the tips of the pair of electrodes
Is preferably in the range of 2 <d (mm).

It is preferable that the high-intensity discharge lamp is a metal halide lamp containing at least indium halide as the light emitting substance in the arc tube.

[0019] In a preferred embodiment, a reflection mirror for reflecting light emitted from the high-intensity discharge lamp is further provided, and an arc center of the mercury-free high-intensity discharge lamp is provided on an optical axis of the reflection mirror. Are arranged.

The mercury-free metal halide lamp according to the present invention comprises an arc tube in which a pair of electrodes are arranged in a tube in which a luminescent material is enclosed, and a rare gas and an indium halide as the luminescent material are provided in the arc tube. And at least is not included, and mercury is not included as the light-emitting substance, and the distance between the tips of the pair of electrodes is d (mm).
And Pd ≦ 4.6 is satisfied when the filling pressure of the rare gas at room temperature is P (MPa).

The filling pressure P of the rare gas is 0.3 at room temperature.
(MPa) or more is preferable.

The distance d is preferably 2 (mm) or more.

In a preferred embodiment, the lighting direction of the metal halide lamp is vertical.

In a preferred embodiment, the lighting direction of the metal halide lamp is horizontal, and a magnetic field containing a component substantially perpendicular to a straight line connecting the tips of the pair of electrodes is applied, whereby an arc is generated. A magnetic field applying unit that suppresses bending is further provided.

In a preferred embodiment, the metal halide lamp is an AC lighting type in which an AC current is supplied to the pair of electrodes.

In a preferred embodiment, the luminous substance contains scandium halide, sodium halide, and thallium halide in the arc tube.

In a preferred embodiment, the halogen constituting the halide is at least one selected from the group consisting of iodine and bromine.

In a preferred embodiment, the rare gas is Xe (xenon).

[0029] In a preferred embodiment, further, a reflector for reflecting light emitted from the mercury-free metal halide lamp is provided, and an arc center of the mercury-free metal halide lamp is arranged on an optical axis of the reflector. Has been done.

In the mercury-free high-intensity discharge lamp lighting device of the present invention, the magnetic field applied to the center between the tips of the pair of electrodes is set to B
(MT), and the distance between the tips of the pair of electrodes is d (mm)
And the pressure inside the arc tube during steady lighting is P ₀ (MP
a), the power consumed during steady lighting is W (W), and the stable frequency during steady lighting is f (Hz), the relationship of 0 <(100BW / f) -P ₀ d <100,
Alternatively, the filling pressure of the rare gas at 20 ° C. is set to P (MP
In case of a), 0 <(10BW / f) -Pd <10
Since the relationship of is satisfied, the fluctuation of the arc can be suppressed and the flicker can be prevented.

Further, since it is possible to prevent the arc from sticking to the tube wall of the arc tube, the life characteristics can be made excellent. That is, {(100 BW / f) -P ₀ d}
When the value of or the value of {(10BW / f) -P · d} is 0 or less, the arc is curved and follows the pipe wall,
The temperature of the upper part of the arc tube rises, causing devitrification or deformation of the arc tube of the mercury-free high-intensity discharge lamp lighting device, resulting in deterioration of life characteristics. The present invention makes it possible to prevent such deterioration of life characteristics.

When the value of P · d is less than 8, the effect of lowering the starting voltage can be obtained. That is, P · d
When the value of is 8 or more, the starting voltage may exceed 30 (kV). Since the drive circuit for generating the starting voltage exceeding 30 kV becomes large in size, it is preferable that the value of P · d is in the range below 8. Furthermore, Pd
When the value of is 6 or less, the starting voltage can be 25 (kV) or less. As a drive circuit, a circuit driven with a starting voltage of 25 (kV) or lower can be made more compact. Therefore, by setting the value of P · d to 6 or less, the effect of downsizing the circuit can be obtained. You can It is more preferable to set the value of P · d to 4.6 or less.

The value of the filling pressure P of the rare gas at 20 ° C. is set to 0.
When it is 1 MPa or more, the effect of further enhancing the stability of the arc can be obtained. If the value of P is 0.3 MPa or more,
The effect of maintaining the stability of the arc can be obtained even when the enclosed material immediately after lighting is not evaporated. Furthermore, if the value of P is 0.
When it is 5 (MPa) or more, heat conduction in the arc tube can be promoted, and the time until the temperature of the arc tube becomes stable can be shortened. As a result, it is possible to shorten the time until the inclusions evaporate, and as a result, the stabilization time of the mercury-free high-intensity discharge lamp lighting device can be shortened.

When the value of P is 2.5 (MPa) or less,
It is possible to effectively prevent the arc tube from bursting. That is, when the value of P exceeds 2.5 (MPa), the pressure P _{0 in} the arc tube during lighting is 25 (MP
As a result, the phenomenon in which the arc tube is destroyed during lighting is likely to occur. Therefore, the value of P is 2.
It is preferably 5 (MPa) or less.

When the value of P is 2.0 (MPa) or less,
The effect of lowering the starting voltage can be obtained. That is,
If the value of P exceeds 2.0 (MPa), the starting voltage at the start of lighting may exceed 30 (kV). 30 (k
The problem is that the drive circuit of the mercury-free high-intensity discharge lamp lighting device that generates a starting voltage exceeding V) becomes large. Therefore, the value of P is preferably 2.0 (MPa) or less from the viewpoint of downsizing of the device. In addition, when a starting voltage of 30 (kV) or more is applied, the starting voltage itself is generated as a large noise, which causes a problem that it affects peripheral devices of the lamp. In addition, the insulating material that constitutes the mercury-free high-intensity discharge lamp lighting device also requires higher insulation, which is a cost disadvantage. Therefore, P
It is preferable that the value of is 2.0 (MPa) or less.

When the lighting frequency f exceeds 40 (Hz), the life characteristics can be improved more effectively. That is, when the lighting frequency f is set to 40 (Hz) or less, the time during which the electrons collide with the electrode on one side becomes longer during the polarity reversal, the temperature of the electrode tip rises, and the consumption of the electrode is promoted. Because it will be.

When the magnetic field B is less than 500 (mT), it is possible to reduce the influence of noise on the lead-in wire and peripheral electric equipment. That is, when a magnetic field is applied to the arc, the magnetic field is generated not only in the arc but also in the periphery. However, when the magnetic field B applied to the center between the electrodes in the steady state is 500 (mT) or more, it is applied to the periphery. The magnetic field increases. Therefore, noise is generated in the lead-in wire and the electric equipment in the vicinity, and as a result, malfunction occurs. Therefore, it is preferable that the magnetic field B is below 500 (mT).

When the distance d between the electrode tips exceeds 2 (mm), the consumption of the electrodes can be prevented and the life characteristics can be improved more effectively. That is, when the distance d between the electrode tips is set to 2 (mm) or less, it becomes difficult to obtain an appropriate lamp voltage (for example, 60 (V) or more) in a mercury-free mercury-free metal halide lamp. As a result, the lamp current value rises, the electrode tip temperature rises, and the electrode wear is promoted. From this, the distance between the electrode tips is 2 (m
m) is preferable. Considering manufacturing variations, it is more preferable to set it to 3 (mm) or more from the viewpoint of stably obtaining 60 (V) or more.

Further, when a reflecting mirror is provided and the center of the arc is arranged on the optical axis of the reflecting mirror, the light from the arc can be effectively projected, and as a result, a high efficiency of mercury-free silver can be achieved. A brightness discharge lamp lighting device can be provided. Further, according to this configuration, it is possible to easily realize a high-intensity discharge lamp whose arc position can be controlled.

According to the mercury-free metal halide lamp of the present invention, when the distance between the tips of the pair of electrodes is d (mm) and the rare gas filling pressure at room temperature is P (MPa),
Since Pd ≦ 4.6 is satisfied, the fluctuation of the arc can be suppressed and the flicker can be prevented. That is, it is possible to eliminate the flicker when a metal halide lamp containing no mercury is lit and to obtain a stable arc.

[0041]

BEST MODE FOR CARRYING OUT THE INVENTION First, before explaining the embodiments of the present invention, a conventional metal halide lamp containing mercury,
The findings obtained by the inventor of the present application will be described by a comparative study with a mercury-free metal halide lamp containing no mercury.

The conventional metal halide lamp examined by the inventor of the present application is a Sc—Na-based metal halide lamp which is generally known to have good light emitting characteristics. In the structure shown in FIG. , Mercury (H
g), scandium iodide (ScI ₃ ), and sodium iodide (NaI). On the other hand, the mercury-free metal halide lamp uses trivalent indium iodide (InI ₃ ) and thallium iodide (Tl) as the light-emitting substance 6.
I), scandium iodide (ScI ₃ ), and sodium iodide (NaI), and does not contain mercury (Hg). In both cases, the tip distance between the pair of electrodes 3 is about 4 mm, and the inner volume of the arc tube 1 is about 0.025.
cc, and inside the arc tube 1 is about 1.4 at room temperature.
Xenon gas of MPa is enclosed.

In the structure in which both of these lamps are horizontally lit with a rectangular wave having a frequency of 400 Hz, the magnitude of the magnetic field required to eliminate the curvature of the arc is investigated, and FIG.
As shown in (a) and (b), the position of the ferrite permanent magnet 10 was moved to examine the influence of the direction of the magnetic field. In the configuration shown in FIG. 3A, the ferrite permanent magnet 10 is arranged in the lower part of the arc tube 1, while in the configuration shown in FIG. 3B, the ferrite permanent magnet 10 is arranged in the upper part of the arc tube 1. did. In either configuration, the ferrite permanent magnet 10 applies a magnetic field in a direction perpendicular to the arc and a magnetic field in a vertical direction, although the directions of the magnetic fields are opposite. The results were as follows.

In the case of the conventional mercury-containing lamp, the magnet 1 is placed on the top.
When 0 is arranged (FIG. 3 (b)), the effect of suppressing the arc is obtained at 0.05T, but when the magnet 10 is arranged in the lower part (FIG. 3 (a)), the arc curvature is reversed. Getting bigger,
The effect of arc suppression was not obtained. On the other hand, in the case of the mercury-free lamp, surprisingly, the effect of suppressing the curvature of the arc was obtained at 0.01 T when the magnet 10 was arranged on either the upper part or the lower part. For both lamps,
Although the polarities of the N pole and the S pole were changed, the effects were the same and no polarity dependence was observed. It is thought that such a surprising phenomenon occurs because the principle of arc curvature suppression is different between the mercury-containing lamp and the mercury-free lamp,
The exact reason is not yet known at this time.

Focusing on the magnetic flux density required for suppressing arc bending, the magnetic flux density of the mercury-containing lamp was 0.05 T, while that of the mercury-free lamp was 0.05 which was 1/5 of that.
Only 1T was needed. This means the following. That is, in the case of a mercury-containing lamp, a relatively large magnetic flux density of 0.05T is required to obtain the arc curving suppression effect, and therefore, it is necessary to use a rare earth magnet having a strong magnetic flux density. On the other hand, in the case of a mercury-free lamp, it is possible to obtain the arc curving suppression effect by using a relatively inexpensive ferrite permanent magnet.

The inventor of the present application further studied, and the strength B of the magnetic field having a component in the same direction as the arc bending direction, the lamp current I, the interelectrode distance d, the lighting frequency f, and the magnetic field were applied. The following equation 1 (proportional relationship) F ∝ (B · I · d) / f (Equation 1) holds between the magnitude F of the force to suppress the arc bending when it is applied. Experimentally found. These findings by the inventor of the present application are described in detail in Japanese Patent Application No. 2000-388000 (corresponding US Patent Application No. 09/739974, applicant: Matsushita Electric Industrial Co., Ltd.). The specification is incorporated herein by reference.

Although it has been confirmed that the curved portion of the arc can be moved downward by F shown in the equation 1 to suppress the curved arc, further examination will continue, and the arc itself becomes unstable depending on the conditions. The phenomenon that the arc fluctuates was observed. The magnetic field B, the current I, the inter-electrode distance d, and the lighting frequency f can be considered as parameters that affect the fluctuation of the arc, but there is a direct relationship between each of these parameters and the fluctuation of the arc. The present inventor confirmed by experiments that there is no correlation. Therefore, the inventor of the present application focused on convection, which is another factor that affects the arc.

As a result of further study focusing on convection, the inventor of the present application has found that the upward force of the arc acts in proportion to P · d. On the other hand, it was also deduced that the downward force of the arc worked in proportion to (BW / f) obtained by transforming the above-mentioned term of (B · I · d) / f. Therefore, it was found that the curvature of the arc changes depending on the balance of these forces. Hereinafter, the principle of the upward force of the arc will be described, and then the downward force of the arc will be described. <Arc Upward Force> In order to express the arc upward force due to convection with an equation on the assumption that the arc 7 is curved due to upward convection between the tips of the electrodes 3 in the arc tube 1, Thought of the model. The model is shown in FIG.

FIG. 4 is a model of the interior of the arc tube 1 shown in FIG. 1, and the upward force applied to the arc 7 generated between the pair of electrodes 3 and 3 is F1. Around the arc 7, there is a gas 8 located near the wall of the arc tube 1. The gas density of the gas 8 near the tube wall is Pw, the gas density in the arc 7 is Pa, the effective radius of the arc 7 is R, the gravity is g, and the distance between the tips of the electrodes 3 and 3 is d. Then, the upward force F1 due to convection (that is, the buoyancy F1 acting on the arc 7) can be expressed by the following Expression 2. In modeling, the outer shapes of the arc 7 and the gas 8 are regarded as cylinders.

F1 = π · R ² · d (Pw−Pa) g (Equation 2) Next, assuming that the gas temperature in the arc 7 is uniform, Ta
And assuming that the temperature of the gas 8 near the pipe wall is uniform, T
If w, then Equation 2 can be transformed into Equation 3 below from the equation of state of gas.

F1 = π · R ² · d · Pa · (Tw−Ta) / Ta · g (Equation 3) Here, Pw can be largely changed by changing the gas pressure to be enclosed. it can. On the other hand, (Tw-T
The change in a) / Ta is small with respect to the change in Pw and can be ignored. Therefore, Equation 3 can be transformed into Equation 4 below.

F1 ∝ Pa · d (Equation 4) In Equation 4, since Pa can be regarded as being proportional to the gas pressure P to be enclosed, Equation 4 can be rewritten as Equation 5 below.

F1 ∝ P · d (Equation 5) From Equation 5, it can be seen that the upward force due to convection is proportional to P · d. Therefore, the arc bending amount is proportional to P · d. <Arc Downward Force> First, before explaining the arc downward force, the Lorentz force will be described. When a magnetic field is applied in a direction perpendicular to the arc 7 of the horizontally lit lamp and in the vertical direction, a Lorentz force is applied in the lateral direction (horizontal direction) of the arc according to Fleming's left-hand rule.
When the lamp current is I and the distance between the electrodes is d, the Lorentz force applied in the lateral direction is F (Lorentz force) =
It becomes BId. Since the lamp voltage V is proportional to L, B
Id is proportional to BW and is BW ∝ BId.

Since the downward force of the arc (hereinafter referred to as "F2") is not applied in the lateral direction of the arc but in the downward direction of the vertical direction, it is not the same as the Lorentz force, but (B.I. It seems possible to transform d) / f into BW / f as well.

Further, the inventor of the present application has found that the downward force F of the arc is
It was also confirmed experimentally that 2 is proportional to BW / f. Based on the results of the experiment, it was found that the downward force F2 that suppresses the arc bending can be represented by 10 BW / f. That is, the downward force that suppresses arc bending increases in proportion to the strength of the magnetic field B, is proportional to the electric power W consumed during lighting, and is inversely proportional to the lighting frequency f.

FIG. 5 shows the relationship between the arc bending amount and BW / f.
Shown in. The curvature rate of the arc in FIG. 5 represents the curvature of the arc when the state where the arc is attached to the tube wall is 100% and the state where the arc is straight is 0%. In addition,
FIG. 5 shows an experiment conducted in a configuration where the value of Pd is 6. As can be understood from FIG. 5, as the value of BW / f increases, the curvature rate of the arc decreases, and the downward force for suppressing the arc curvature increases. When the value of BW / f exceeded 10, the arc curvature (%) became 0, and the arc became straight (straight).

The inventor of the present application has found out that in order to balance the upward force F1 of the arc and the downward direction F2 of the arc described above and suppress the fluctuation of the arc, the structure of the lamp may be as follows. The present invention has been reached.

The magnetic field applied to the center between the tips of the pair of electrodes 3 is B (mT) and the distance between the tips of the pair of electrodes 3 is d (mm). When the pipe pressure (operating pressure) is P ₀ (MPa), the power consumed during steady lighting is W (W), and the stable frequency during steady lighting is f (Hz), 0 <(100BW / f ) -P ₀ d <100 (Equation 6). (10 in Equation 6
0BW / f) is the term of the arc downward force F2,
The term P ₀ d is the term of the arc upward force F1.

"100" in the item (100 BW / f)
Is a coefficient for matching the dimensions and is an experimentally obtained coefficient. That is, 100 BW / f of the force F2 that suppresses arc bending and the force F2 that bends arc.
P ₀ · d of is balanced by a factor of 100 applied to BW / f, and (100 BW / f) −P ₀ d is proportional to the curvature of the arc. Therefore, 100 BW / f-
As P ₀ d increases, the arc curvature increases and P
-When d-10BW / f becomes small, the curvature of the arc becomes small.

On the other hand, the internal pressure P of the arc tube 1 during steady lighting is P.
_Since there is an empirical rule that ₀ (MPa) is about 10 times the filling pressure P (MPa) of the rare gas in the mercury-free metal halide lamp, the equation 6 can be transformed into the following equation 7. In that case, a factor of 10 balances F1 and F2.

0 <(10 BW / f) −Pd <10 (Equation 7) In Equation 7, the filling pressure of the rare gas at 20 ° C. is P (MP
a). The internal pressure P ₀ of the arc tube 1 is the filling pressure P
Thermodynamically explaining that it will be about 10 times that is as follows. In a mercury-free metal halide lamp, a rare gas and a metal halide gas exist in the arc tube while the lamp is on. The temperature at the center of the arc is 5000 during lighting.
At 6000K, the temperature near the tube wall of the arc tube is 1000.
K, therefore the average gas temperature in the arc tube 1 is about 3
You can think of it as 000K. About 3000K during lighting
Is about 10 times higher than room temperature 293K, so the pressure is about 10 times higher from the equation of state of gas. For example, when the filling pressure P of the rare gas is 1.0 MPa, the pressure P ₀ during lighting is
It becomes 10 MPa. FIG. 6 shows the pressure inside the arc tube 1 at the time of lighting.

As shown in FIG. 6, when the pressure P ₀ when the rare gas is turned on is 10 MPa, the gas pressure of the metal halide is 1 MPa, which is 1/10 of that of the rare gas. Therefore, since the pressure due to the rare gas is the majority,
Even if the influence of the metal halide is ignored, no particular problem occurs. Therefore, it is possible to substantially adopt a configuration based on the rare gas filling pressure P at 20 ° C. In the case of a mercury-containing metal halide lamp, Hg gas occupies a ratio of about 30 when the total pressure in the arc tube 1 at the time of lighting is 100, so the rare gas filling pressure P at 20 ° C. With the configuration based on, there is a possibility that the characteristics of the actually lit lamp may not be reflected. Further, even in the case of a mercury-free metal halide lamp, if the metal halide gas is present so that it cannot be ignored with respect to the rare gas, the filling pressure P of the rare gas at 20 ° C.
It is preferable to adopt the configuration based on the tube internal pressure P ₀ of the arc tube 1 rather than the configuration based on the above because the characteristics of the lamp can be reflected more accurately.

Embodiments according to the present invention will be described below with reference to the drawings. In the following drawings, for simplification of description, components having substantially the same function are designated by the same reference numeral. The present invention is not limited to the embodiments below. (Embodiment 1) Embodiment 1 of the present invention will be described with reference to FIGS. In the first embodiment, characteristics when the magnetic field B applied to the arc is changed will be mainly described. FIG. 7 schematically shows the configuration of the mercury-free high-intensity discharge lamp lighting device 100 according to the first embodiment. On the other hand, FIG. 8 schematically shows a cross-sectional structure of the high-intensity discharge lamp 11 included in the lamp lighting device 100.

As shown in FIG. 7, the lamp lighting device 100 of the present embodiment has a high-intensity discharge lamp 11 and a lamp 11.
And a lighting circuit 12 for lighting. As shown in FIG. 8, the high-intensity discharge lamp 11 includes an arc tube 1 in which a pair of electrodes 3 and 3 are arranged in a tube in which a luminescent material 6 is enclosed.
It is a lamp including.

The high-intensity discharge lamp 11 of this embodiment does not contain mercury (Hg) as the light emitting substance 6, and
The metal halide lamp is arranged so that a straight line connecting the tips of the pair of electrodes 3 and 3 is substantially horizontal and is lit horizontally. The lighting circuit 12 shown in FIG. 7 is provided with an alternating current generating means for supplying an alternating current to the pair of electrodes 3 (or the pair of external leads 5). As the alternating current generating means, a known one may be used. The lamp 11 is electrically connected to the lighting circuit 12 in a state where the axes of the pair of electrodes 3, 3 are horizontal, and the connected lamp 11 is supplied with, for example, a rectangular wave alternating current and lights at a rated power. It will be.

The structure of the lighting circuit 12 will be described in detail.
The lighting circuit 12 in the present embodiment is designed so that the lighting frequency and the lighting power can be freely set, and when the power is turned on, a pulse voltage of about 20 (kV) is continuously applied between the electrodes of the lamp. Is applied. This creates an arc between the lamp electrodes and starts the lamp 11. When the lamp 11 starts, the voltage between the electrodes drops to several tens of volts. At the same time, the lamp current increases. At this time, the frequency of the lighting circuit 12 is the set frequency (for example, 150H).
Current is supplied to the lamp 11 at a constant z. When the use of the lamp 11 is especially for automobiles, it is required that the light rises quickly after the switch is turned on. Therefore, for several seconds to several tens of seconds until the voltage of the lamp becomes stable, about twice the rated power is required. Supply. When the lamp is stable, the lighting circuit 12 has a set power with a rectangular wave of a set frequency.
It has the function of adjusting the lamp current according to the lamp voltage. A function of changing the frequency may be provided only at the initial stage of lighting when the lamp power W is high. Further, in order to absorb variations in the optimum frequency of the product, a function of temporally changing the lighting frequency may be provided, for example.

Next, the lamp 11 will be described in more detail. The arc tube 1 is made of, for example, quartz glass, and its internal volume V is about 0.025 (cc). A pair of electrodes 3,
The distance d between the tips of 3 is 4 (mm). Inclusion 6
Is a metal halide, and the inclusion 6 does not contain mercury. A central portion between a pair of electrodes of the arc tube 1,
The inner diameter (hereinafter referred to as the inner diameter) of the arc tube 1 in the direction perpendicular to the straight line connecting the electrodes is about 2.8 (mm). The arc tube 1 is covered with an outer tube 14, and the outer tube 14 is fixed to a base 13.

The pair of electrodes 3, 3 are connected to the external lead wire 5 via the metal foil 4 sealed at the side of the arc tube 1, respectively. The lamp 11 includes a magnetic field applying unit 10 that applies a magnetic field including a component that is substantially perpendicular to a straight line connecting the tips of the pair of electrodes 3 and 3 in a substantially vertical direction. In the present embodiment, the magnetic field is applied. A permanent magnet 10 is used as the means 10, and the permanent magnet 10 that makes the magnetic field B applied to the arc 4.0 (mT) is fixed to one of the external lead wires 5. The permanent magnet 10 forms a magnetic field in the arc portion between the electrodes 3 and 3 in which the direction of the lines of magnetic force is the vertical direction.

The inclusion 6 enclosed in the arc tube 1 is, for example, +3 valent indium iodide (InI ₃ ), thallium iodide (TlI), scandium iodide (ScI ₃ ) and sodium iodide (NaI). Is. Although not shown in the drawing, xenon, which is a rare gas, is sealed at 20 ° C. and 1.0 (MPa).

In the lamp 11 of this embodiment, the magnetic field applied to the center between the tips of the pair of electrodes (3, 3) is B (m
T), the distance between the tips of the pair of electrodes 3 is d (mm), and the internal pressure (operating pressure) of the arc tube 1 during steady lighting is P
₀ (MPa), and the power consumed during steady lighting is W
When (W) and the stable frequency during steady lighting is f (Hz), the relationship of 0 <(100BW / f) −P ₀ d <100 (Equation 6) is satisfied.

Further, the filling pressure of the rare gas at 20 ° C. is set to P
(MPa), the relationship of 0 <(10BW / f) −Pd <10 (Equation 7) is satisfied. It is easier to measure the rare gas filling pressure P than the operating pressure P ₀ , and the operating pressure P
_Since there is no particular problem even if it is specified by the rare gas filling pressure P instead of ₀ , it is more advantageous in designing the lamp to define the configuration by Expression 7. However, of course, the operating pressure P ₀
There is no problem with defining the configuration by Equation 6 including

By adopting a structure satisfying these relationships, the mercury-free high-intensity discharge lamp lighting device 100 in which the fluctuation of the arc is suppressed is realized. Among various experiments conducted by the inventor of the present application, the conditions of the lamp lighting device 100 exhibiting the most preferable effects are as follows.
Conditions not shown below use the above-mentioned configuration. For example, the internal volume V of the arc tube 1 is about 0.025.
It is cc. <Enclosure> trivalent indium iodide (InI _3): 0.1mg thallium iodide (TlI): 0.1 mg scandium iodide (ScI _3): 0.19mg Sodium iodide (NaI): 0.06 mg < Noble gas> Xenon gas: 1.4 MPa (filling pressure at 20 ° C.) <Distance between electrodes> d: 4 mm <Lighting condition> B: 5 mT, W: 35 W, f: 150 Hz In the above condition configuration, 0 <(100 BW / F) -P ₀ d <100 (Equation 6) ≈0 <(10 BW / f) -Pd <10 (Equation 7) = 5.3. Those based on this condition did not feel any flicker (light output fluctuation: less than 1%), and devitrification was not observed during the life of the lamp.

Although four kinds of metal halides have been shown in the present embodiment and the examples of the preferable conditions described above, the present invention is not limited thereto. The reason is that, as shown in FIG. 6, in the mercury-free high-intensity discharge lamp, the proportion of the gas of the metal halide when the lamp is lit is smaller than that of the rare gas (xenon), and the upward force of the arc ( buoyancy)
This is because F1 is almost due to the rare gas and does not depend on the type of metal halide. The metal halide is not limited to iodide, and may be bromide or chloride, or may be other elemental metal element or its compound.

Among the halides, indium halides, preferably InI ₃ and / or InI
Since (in particular, InI ₃ ) increases the lamp voltage, it can be lit with a small current, the lighting circuit can be downsized, and the luminous efficiency can be increased.
From a practical point of view, it is preferable to include it in the arc tube 1.
InI ₃ , InI, or TlI is a halide having a high vapor pressure. For example, a metal halide (including InI ₃ ) having a vapor pressure of 1 atm or more at 900 ° C. is suitable as the enclosure 6 for the metal halide lamp. Can be used for.

Further, although xenon gas is used as the rare gas in the present embodiment, it is not limited to this and any rare gas such as argon, krypton or a mixed gas thereof may be used. Further, since the upward force F1 of the arc is based on the term of Pd, it does not depend on the shape or internal volume of the arc tube 1. This is the arc tube 1
This is because the element of the shape and the internal volume can be considered to have already been reflected in the element of the pressure P. Therefore, in this embodiment, the inner volume V of the arc tube is set to about 0.02.
Although it is set to 5 (cc), it is not limited to this. In addition, although the present embodiment shows the case where the constituent material of the arc tube 1 is quartz glass, the arc tube material is not limited to this, and may be composed of, for example, a ceramic material such as alumina or YAG. Good. In the present embodiment, the arc tube 1 has a structure covered with the outer tube 14, but the structure is not limited to this, and, of course, a structure without the outer tube 14 may be used.

Further, the permanent magnet 10 has the external lead wire 5
However, the magnetic field as shown in the present embodiment may be securely fixed so that it can be formed in the arc tube. Further, the same effect can be obtained by using an electromagnet or the like as the magnetic field applying means instead of the permanent magnet 10. As the permanent magnet 10, a ferrite permanent magnet, an alnico magnet, a rare earth permanent magnet, or the like can be used. Ferrite permanent magnets are inexpensive and general, and therefore advantageous in terms of cost. However, in consideration of the influence of the decrease in magnetic force due to the temperature rise, it is preferable to arrange the lamp in a place where the heat of the lamp is not easily received. If the alnico magnet is used, it can be arranged near the lamp because the magnetic force does not decrease even if the temperature rises. Further, it is possible to use a smaller one than the ferrite permanent magnet. If the rare earth permanent magnet has a very strong magnetic force, it is possible to use a smaller one.

The direction of the magnetic lines of force (polarity of N-curve and S-curve)
Is not particularly limited. The number of permanent magnets and electromagnets is not limited to one, and may be provided both above and below the arc tube 1. Further, in the present embodiment, the current waveform applied from the lighting circuit 12 to the lamp 11 is a rectangular wave,
For example, a sine wave or a triangular wave may be used.

The following is an experiment conducted by the inventor of the present application to examine the extent of the arc fluctuation (flicker) and its suppression, and the results thereof. To check the fluctuation of the arc,
It is sufficient to check the fluctuation of the light output. FIG. 9 schematically shows the configuration of the experimental apparatus used for measuring the light output fluctuation.

As shown in FIG. 9, in order to quantify the curvature and flicker of the arc, the measuring head 42 of the illuminometer 40 is arranged near the lamp 11, and the illuminometer 4 is used.
The change in the optical output of 0 was observed by the oscilloscope 41 through a low pass filter (LPF) for noise cutting. In addition, the CCD 50 captures an image of the arc bending and flicker of the lamp 11, and the captured image is recorded as V.
The captured image is stored in the TR60 and the captured image is displayed on the monitor 7.
Displayed at 0, whereby the subject observed the state of arc bending and flicker. The lamp 11 and CCD
The filter 20 was disposed between the filter 50 and the filter 50.

Further, a life test was also conducted. The life test was carried out by repeating this mode by blinking and turning on the mode shown in Table 1 below as one cycle. The entire lighting time was defined as the lighting time.

[0081]

[Table 1]

In this experiment, arc curving, flicker, and life characteristics were measured using the lighting circuit 12 with the power W consumed by the lamp 11 in the steady state and the lighting frequency f in the steady state as parameters. . Power W is 2
The parameters were set to 4 levels of 0, 35, 50, 70 (W), and the lighting frequency f was measured between 30 and 20000 (Hz) so as not to cause acoustic resonance. The lighting current waveform was measured as a rectangular wave. The results are shown in FIGS. 10 and 11.

FIG. 10 is a graph showing the result of examining the flicker by measuring the fluctuation of the light output. Figure 1
The horizontal axis of 0 indicates the value of 10 BW / f−P · d when the pressure of the rare gas is P (MPa), and the vertical axis indicates the fluctuation (%) of the optical output. Here, the fluctuation of the light output is a value obtained by dividing the difference between the maximum value and the minimum value of the light output by the average value of the light output by (%).

As can be seen from FIG. 10, the fluctuation of the light output of the lamp 11 depends on 10 BW / f−P · d.
When 10 BW / f−P · d exceeds 7, the fluctuation of the optical output exceeds 1 (%), which is a level at which fluctuation can be said to have occurred. Furthermore, when 10BW / fPd exceeds 10,
The fluctuation of the light output exceeds 6%. When this 6% was exceeded, the subject felt a flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

FIG. 11 is a graph showing the results of examining the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube. The horizontal axis in FIG. 11 indicates the value of 10 BW / f−P · d as in the case of FIG.
The vertical axis represents the value obtained by dividing the amount of change in the inner diameter of the arc tube 1 after blinking for 1000 hours by the initial inner diameter of the arc tube 1 by (%).

As can be seen from FIG. 11, the change in the inner diameter of the arc tube 1 of the lamp depends on 10 BW / f−P · d. When the value of 10 BW / fPd was less than 0, the change in the inner diameter of the arc tube exceeded 5 (%). At this time, a change in the arc position occurs, and the initial light flux is changed to 70
(%) Or less, the luminous flux is reduced and the change in color temperature is 300
Results exceeding (K) were also shown, and it was confirmed that the life characteristics were deteriorated. Although the inner diameter of the arc tube is small, if the value of 10BW / fPd is less than 2,
Devitrification was observed at the top of the arc tube.

Therefore, by defining the range of 10 BW / f-P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with a small arc tube deformation and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Here, 0 <10 BW / f−P · d <10
In the lamp lighting device 100 in which f is 40 (Hz) or less, devitrification does not occur in the arc tube 1 and the inner diameter of the arc tube 1 does not change, but the inner wall of the arc tube is black. A change was observed. These lamp lighting devices have the effect of suppressing devitrification and changes in the inner diameter of the arc tube, but have deteriorated life characteristics. Therefore, it is preferable that the lighting frequency in the steady state exceeds 40 (Hz).

Next, a structure similar to that of the lamp lighting device 100, in which the permanent magnet 10 is adjusted so that the magnetic field B applied in the arc is 40 (mT), is shown in FIGS.
3 shows. Also in the results shown in FIGS. 12 and 13, as in the case of FIGS. 10 and 11, the power W consumed in the steady state of the lamp 11 and the lighting frequency in the steady state are used as parameters for flickering and flicker and The life characteristics were measured. W was measured at four levels of 20, 35, 50 and 70 (W), and f was measured between 30 and 20000 (Hz).

FIG. 12 is a graph showing the result of investigating the flicker by measuring the fluctuation of the optical output similarly to FIG. The horizontal axis and the vertical axis in FIG. 12 are the same as those in FIG.

As can be seen from FIG. 12, a magnetic field of 40 (m
Even when the magnetic field is set to T), the fluctuation in the light output of the lamp 11 is 10 BW /, as in the case where the magnetic field shown in FIG. 10 is 4 (mT).
f-P · d. When 10 BW / f−P · d exceeds 7, the fluctuation of the optical output exceeds approximately 1 (%), which is a level at which fluctuation can be said to have occurred. Furthermore, 10 BW /
When f-P · d exceeded 10, the fluctuation in light output exceeded approximately 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

Here, 0 <10 BW / f−P · d <10
In the lamp lighting device 100 in which f is 40 (Hz) or less, devitrification does not occur in the arc tube 1 and the inner diameter of the arc tube 1 does not change, but the inner wall of the arc tube is black. A change was observed. These lamp lighting devices have the effect of suppressing devitrification and changes in the inner diameter of the arc tube, but have deteriorated life characteristics. Therefore, it is preferable that the lighting frequency in the steady state exceeds 40 (Hz).

FIG. 13 is a graph showing the results of examining the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube similarly to FIG. The horizontal axis and the vertical axis in FIG. 13 are the same as those in FIG.

As can be seen from FIG. 13, a magnetic field of 40 (m
Even when the magnetic field is set to T), as in the case where the magnetic field shown in FIG. 11 is 4 (mT), the change in the inner diameter of the arc tube 1 is 10 BW / f-
It depends on P · d. When the value of 10 BW / f−P · d was less than 0, the change in the inner diameter of the arc tube exceeded approximately 5 (%). At this time, a change in the arc position occurs, the luminous flux is reduced to 70% or less with respect to the initial luminous flux, and the change in color temperature exceeds 300 (K). Was confirmed. Although the inner diameter of the arc tube was small, devitrification was observed in the upper part of the arc tube when the value of 10BW / fP · d was less than 2.

Therefore, by defining the range of 10 BW / fP · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with a small arc tube deformation and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

14 and 15 show a structure similar to that of the lamp lighting device 100, in which the permanent magnet 10 is adjusted so that the magnetic field B applied in the arc is 400 (mT). Also in the results shown in FIG. 14 and FIG. 15, the flicker and life characteristics were measured using the power W consumed in the steady state of the lamp 11 and the steady-state lighting frequency f as parameters. W is 20, 35, 50,
We pretend to be 4 levels of 70 (W) and f is 30 to 20000 (H
It was measured during z).

FIG. 14 is a graph showing the result of examining the flicker by measuring the fluctuation of the optical output as in the case of FIG. The horizontal axis and the vertical axis in FIG. 14 are the same as those in FIG.

As can be seen from FIG. 14, a magnetic field of 400
Even when set to (mT), the magnetic field shown in FIG.
As in the case of T), the fluctuation of the light output of the lamp 11 is 10
It depends on BW / fPd. When 10 BW / f−P · d exceeds 7, the fluctuation of the optical output exceeds approximately 1 (%), which is a level at which fluctuation can be said to have occurred. Furthermore, 1
When 0BW / fPd exceeded 10, the fluctuation of the optical output exceeded about 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

Here, 0 <10 BW / f−P · d <10
In the lamp lighting device 100 in which f is 40 (Hz) or less, devitrification does not occur in the arc tube 1 and the inner diameter of the arc tube 1 does not change, but the inner wall of the arc tube is black. A change was observed. These lamp lighting devices have the effect of suppressing devitrification and changes in the inner diameter of the arc tube, but have deteriorated life characteristics. Therefore, it is preferable that the lighting frequency in the steady state exceeds 40 (Hz).

FIG. 15 is a graph showing the results of examining the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube as in FIG. The horizontal axis and the vertical axis in FIG. 15 are the same as those in FIG.

As can be seen from FIG. 15, a magnetic field of 400
Even when set to (mT), the magnetic field shown in FIG.
As in the case of T), the change in the inner diameter of the arc tube 1 is 10 BW.
/ F-P · d. When the value of 10BW / fP · d is less than 0, the change of the inner diameter of the arc tube is about 5
(%) Exceeded. At this time, the arc position changes,
Further, it was confirmed that the luminous flux decreased to 70% or less with respect to the initial luminous flux and the change in color temperature exceeded 300 (K), which confirmed that the life characteristics were deteriorated. Also,
10BW / fP ・
When the value of d was less than 2, devitrification was observed at the top of the arc tube.

Therefore, by defining the range of 10 BW / f-P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with a small arc tube deformation and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Further, a similar test was conducted, and the high-intensity actinic lamp device 10 in which the magnetic field applied in the arc was 500 (mT).
When performed at 0, in the range of 0 <10 BW / f−P · d <10, as in the case where a magnetic field of 4 (mT) was applied, there was no flicker and the silver-free high silver was excellent in life characteristics. It has been found that a brightness discharge lamp lighting device is realized. However, when a magnetic field of 500 (mT) was applied to the arc, malfunction of the circuit was observed. This is because the magnetic field is applied not only in the arc but also to the circuit and the current supply line. From this fact, the magnetic field applied to the arc should not exceed 500 (mT). Is preferred. (Embodiment 2) In Embodiment 1, the characteristics when the strength of the magnetic field was changed were mainly described, but in this embodiment, when the pressure of the rare gas sealed in the arc tube 1 is changed. The characteristics of will be described. Since the other points are the same as those of the first embodiment, the description thereof will be omitted or simplified.

The mercury-free high-intensity discharge lamp lighting device and the high-intensity discharge lamp of this embodiment have the same structure as that of the mercury-free high-intensity discharge lamp lighting device 100 shown in FIGS. 1 and 2, respectively. In this embodiment, the magnetic field B applied to the arc is fixed to 4.0 (mT), and then the arc tube 2
The pressure P of the xenon gas sealed in 1 is 0.1 (MP
a), and the electric power W consumed in the steady state,
Flickering and life characteristics were measured with the constant lighting frequency as a parameter. Similar to Embodiment 1, W was measured at four levels of 20, 35, 50 and 70 (W), and f was measured between 30 and 20000 (Hz).

FIG. 16 is a graph showing the result of examining the flicker by measuring the fluctuation of the light output as in the case of FIG. The horizontal axis and the vertical axis in FIG. 16 are the same as those in FIG.

As can be seen from FIG. 16, even when the magnetic field is constant and the pressure of the xenon gas is 0.1 MPa, the fluctuation of the light output of the lamp 11 is 10 BW / f−P, as in the first embodiment.・ Depending on d. 10 BW / f
-When P · d exceeds 7, the fluctuation of the optical output is about 1
(%) Was exceeded, and it was at a level where it can be said that fluctuations had occurred.
Further, when 10 BW / fPd exceeds 10, the fluctuation of the optical output exceeds approximately 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

FIG. 17 is a graph showing the results of investigating the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube similarly to FIG. The horizontal axis and the vertical axis in FIG. 17 are the same as those in FIG.

As can be seen from FIG. 17, even when the magnetic field is constant and the pressure of the xenon gas is 0.1 (MPa), the change in the inner diameter of the arc tube 1 is 10 BW / f-P · d. 10 BW / f-
When the value of P · d was less than 0, the change in the inner diameter of the arc tube exceeded about 5 (%). At this time, a change in the arc position occurs, the luminous flux is reduced to 70% or less with respect to the initial luminous flux, and the change in color temperature exceeds 300 (K). Was confirmed.
Also, although the change in the inner diameter of the arc tube is small, 10 BW / f
When the value of −P · d was less than 2, devitrification was observed in the upper part of the arc tube.

Therefore, by defining the range of 10 BW / f-P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with a small arc tube deformation and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Here, 0 <10 BW / f−P · d <10
Even in the case of falling within the range of, in the mercury-free high-intensity discharge lamp lighting device with f of 40 (Hz) or less, the devitrification of the arc tube 1 and the inner diameter of the arc tube 1 are performed as in the first embodiment. Although no change was observed, blackening of the inner wall of the arc tube was observed. These lamp lighting devices have the effect of suppressing devitrification and changes in the inner diameter of the arc tube, but have deteriorated life characteristics. Therefore, the lighting frequency in the steady state is 40
(Hz) is preferable.

Further, the lamp lighting device having a P value of 0.1 (MPa) has the effects of preventing flicker and preventing deterioration of life characteristics, but the following phenomenon was observed. That is, although there was no fluctuation in the light output, when the reflector was combined with the mirror, a phenomenon was occasionally seen in which the arc fluctuated momentarily. In that case, although the fluctuation as the light output was 5 (%) or less, the flicker of the emitted light was observed. When the lamp 11 at this time was observed, it was found that the bright spot at the tip of the electrode had moved. In order to suppress the flicker of the emitted light, the value of the rare gas filling pressure P is set to 0.
It is preferably in the range of more than 1 (MPa).

Next, the pressure P of the xenon gas is set to 2.5 (M
Pa) is shown in FIGS. 18 and 19. Also in the results shown in FIGS. 18 and 19, the flicker and life characteristics were measured using the power W consumed in the steady state of the lamp 11 and the steady-state lighting frequency f as parameters. W is 20, 35, 50, 70
Pretend to be 4 levels of (W), f is 30 to 20000 (Hz)
Measured between.

FIG. 18 is a graph showing the result of examining the flicker by measuring the fluctuation of the optical output as in the case of FIG. The horizontal axis and the vertical axis in FIG. 18 are the same as those in FIG.

As can be seen from FIG. 18, even when the magnetic field is kept constant and the pressure of the xenon gas is 2.5 MPa, the fluctuation in the light output of the lamp 11 is 10 BW / f-P as in the first embodiment.・ Depending on d. 10 BW / f
-When P · d exceeds 7, the fluctuation of the optical output is about 1
(%) Was exceeded, and it was at a level where it can be said that fluctuations had occurred.
Further, when 10 BW / fPd exceeds 10, the fluctuation of the optical output exceeds approximately 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

FIG. 19 is a graph showing the results of examining the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube as in FIG. The horizontal axis and the vertical axis in FIG. 19 are the same as those in FIG.

As can be seen from FIG. 19, even when the magnetic field is kept constant and the pressure of the xenon gas is 2.5 (MPa), the change in the inner diameter of the arc tube 1 is 10 BW / similar to the first embodiment. f-P · d. 10 BW / f-
When the value of P · d was less than 0, the change in the inner diameter of the arc tube exceeded about 5 (%). At this time, a change in the arc position occurs, the luminous flux is reduced to 70% or less with respect to the initial luminous flux, and the change in color temperature exceeds 300 (K). Was confirmed.
Also, although the change in the inner diameter of the arc tube is small, 10 BW / f
When the value of −P · d was less than 2, devitrification was observed in the upper part of the arc tube.

Therefore, by defining the range of 10 BW / f-P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with less deformation of the arc tube and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Here, the mercury-free high-intensity discharge lamp lighting device 100 having a P value of 2.5 (MPa) has the effect of preventing flicker and preventing deterioration of life characteristics, but the number of tests is 15 Two of them were damaged within 1000 hours and turned off. Therefore, considering the usage time of the high-intensity discharge lamp, the value of P is preferably in the range below 2.5 (MPa) from the viewpoint of preventing damage to the arc tube.

Further, when a mercury-free high-intensity discharge lamp lighting device 100 having a P value of 0.3 (MPa) was prepared and flicker and life characteristics were evaluated, it was found that 0 < Within the range of 10 BW / fP · d <10, a mercury-free high-intensity discharge lamp lighting device having no flicker and excellent life characteristics was realized. However, immediately after lighting, flicker due to low pressure was observed. The same phenomenon has been observed even with the enclosure of 0.1 (MPa). It is considered that this is because the heat distribution in the arc becomes non-uniform due to the low pressure immediately after lighting. Therefore, in consideration of avoiding flicker immediately after lighting, it is desirable that the enclosed pressure P of the rare gas is set to a range exceeding 0.3 (MPa).

Next, a mercury-free high-intensity discharge lamp lighting device 100 having a P value of 0.5 (MPa) was produced and flickered,
When the life characteristics were evaluated, as in the first embodiment,
In the case of falling within the range of 0 <10 BW / fP · d <10, it was possible to realize a mercury-free high-intensity discharge lamp lighting device having no flicker and excellent life characteristics. However, a phenomenon was observed in which the time from when the light was turned on until the light output reached 80% of the steady state exceeded 10 seconds. This phenomenon is 0.1 (MPa) and 0.3 (MPa)
It was also observed at the filling pressure of. It is considered that this is because when the filling pressure P of the rare gas is 0.5 (MPa) or less, the heat conduction in the arc tube 21 is small, and the inclusion 6 is less likely to evaporate. Therefore, it is desirable that the filling pressure P of the rare gas is in a range exceeding 0.5 (MPa).

Further, a mercury-free high-intensity discharge lamp lighting device 100 having a P value of 2.0 (MPa) was produced, and flicker and life characteristics were evaluated. As with the first embodiment, 0 <10 BW was obtained. In the range of / f−P · d <10, it was possible to realize a mercury-free high-intensity discharge lamp lighting device without flicker and having excellent life characteristics. However, the result was that the starting voltage exceeded 30 (kV).
The value of P is 2.0 (MPa) because the size of the drive circuit that generates the starting voltage exceeding 30 (kV) becomes large.
It is preferable that the value is less than 8, that is, the value of P · d is less than 8.

Next, a mercury-free high-intensity discharge lamp lighting device 100 having a P value of 1.5 (MPa) was produced, and flickered,
When the life characteristics were evaluated, it was 0 as in the first embodiment.
Within the range of <10 BW / fP · d <10, it was possible to realize a mercury-free high-intensity discharge lamp lighting device which is free from flicker and has excellent life characteristics. However,
In this case, the result was that the starting voltage exceeded 25 (kV). By limiting the starting voltage to 25 (kV) or less, the driving circuit can be made smaller,
The range where the value of P is less than 1.5 (MPa), that is, P
It is more preferable that the value of d is less than 6.
(Embodiment 3) In the present embodiment, characteristics when the distance between the electrode tips of the lamp is changed will be mainly described. Since the other points are the same as those of the first and second embodiments, description thereof will be omitted or simplified.

The mercury-free high-intensity discharge lamp lighting device and the high-intensity discharge lamp of this embodiment have the same structure as the silver-free high-intensity discharge lamp lighting device 100 shown in FIGS. 1 and 2, respectively. In the present embodiment, the magnetic field B applied to the arc is fixed to 4.0 (mT), the pressure of the xenon gas is set to 1.0 (MPa), and then the pair of electrodes 3 and 3 is used.
The distance d between the tips of was set to 2 mm. Then, the flicker and life characteristics were measured with the power W consumed in the steady state and the lighting frequency in the steady state as parameters. Similar to the first embodiment, W is 20, 35, 50,
We pretend to be 4 levels of 70 (W) and f is 30 to 20000 (H
It was measured during z).

FIG. 20 is a graph showing the result of examining the flicker by measuring the fluctuation of the optical output as in the case of FIG. The horizontal axis and the vertical axis in FIG. 20 are the same as those in FIG.

As can be seen from FIG. 20, even when the magnetic field is constant and the distance between the electrode tips is 2.0 (mm), the fluctuation in the light output of the lamp 11 is 10 BW as in the first embodiment. / F-P · d. 10 BW / f
-When P · d exceeds 7, the fluctuation of the optical output is about 1
(%) Was exceeded, and it was at a level where it can be said that fluctuations had occurred.
Further, when 10 BW / fPd exceeds 10, the fluctuation of the optical output exceeds approximately 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

FIG. 21 is a graph showing the results of investigating the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube similarly to FIG. The horizontal axis and the vertical axis in FIG. 21 are the same as those in FIG.

As can be seen from FIG. 21, even when the magnetic field is constant and the distance between the electrode tips is 2.0 (mm), the change in the inner diameter of the arc tube 1 is 10 BW as in the first embodiment. / F-P · d. 10 BW / f-
When the value of P · d was less than 0, the change in the inner diameter of the arc tube exceeded about 5 (%). At this time, a change in the arc position occurs, the luminous flux is reduced to 70% or less with respect to the initial luminous flux, and the change in color temperature exceeds 300 (K). Was confirmed.
Also, although the change in the inner diameter of the arc tube is small, 10 BW / f
When the value of −P · d was less than 2, devitrification was observed in the upper part of the arc tube.

Therefore, by defining the range of 10 BW / f-P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with less deformation of the arc tube and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Here, 0 <10 BW / f−P · d <10
Even in the case of falling within the range of, in the mercury-free high-intensity discharge lamp lighting device with f of 40 (Hz) or less, the devitrification of the arc tube 1 and the inner diameter of the arc tube 1 are performed as in the first embodiment. Although no change was observed, blackening of the inner wall of the arc tube was observed. These lamp lighting devices have the effect of suppressing devitrification and changes in the inner diameter of the arc tube, but have deteriorated life characteristics. Therefore, the lighting frequency in the steady state is 40
(Hz) is preferable.

Further, even when it falls within the range of 0 <10 BW / f−P · d <10, the distance between the electrode tips is 2.0 (m).
At m), the lamp voltage was about 48 (V). 6
In a high-intensity discharge lamp having a lamp voltage lower than 0 (V), devitrification of the arc tube 1 and no change in the inner diameter of the arc tube 1 were observed, but severe wear of the electrode tip was observed. This is considered to be due to the increase in the lamp current value. Therefore, the distance between the electrode tips is 2.0
It is preferably in the range exceeding (mm).

Further, when a mercury-free high-intensity discharge lamp lighting device 100 having a value of d of 3 (mm) was prepared and flicker and life characteristics were evaluated, 0 <1 as in the first embodiment.
In the range of 0BW / fPd <10, it was possible to realize a mercury-free high-intensity discharge lamp lighting device which is free from flicker and has excellent life characteristics. However, in this case, the lamp voltage was 62 (V). It is more than 60 (V) in this range, but if manufacturing variations are taken into consideration, some less than 60 (V) may occur. Therefore, it is more preferable that the range exceeds 3 (mm).

Next, the distance d between the tips of the pair of electrodes 3, 3 is d.
22 and FIG.
Shown in. Also in the results shown in FIGS. 22 and 23,
Flickering and life characteristics were measured with the power W consumed in the steady state of the lamp 11 and the lighting frequency in the steady state as parameters. W is 20, 35, 50, 70
The four levels of (W) were measured, and f was measured between 30 and 20000 (Hz) so that the acoustic resonance phenomenon did not occur. The lighting current waveform was measured as a rectangular wave.

FIG. 22 is a graph showing the result of examining the flicker by measuring the fluctuation of the optical output similarly to FIG. The horizontal axis and the vertical axis in FIG. 22 are the same as those in FIG.

As can be seen from FIG. 22, even when the magnetic field is constant and the distance between the electrode tips is 6.0 (mm), the fluctuation in the light output of the lamp 11 is 10 BW as in the first embodiment. / F-P · d. 10 BW / f
-When P · d exceeds 7, the fluctuation of the optical output is about 1
(%) Was exceeded, and it was at a level where it can be said that fluctuations had occurred.
Further, when 10 BW / fPd exceeds 10, the fluctuation of the optical output exceeds approximately 6%. At this time, the subject felt flicker.

Therefore, 10 BW / fPd is 10
By defining the range not to exceed, it is possible to realize a mercury-free high-intensity discharge lamp in which the subject does not feel flicker. It is more preferable to define 10 BW / f-P · d in a range not exceeding 7, because not only flicker is not felt but also a mercury-free high-intensity discharge lamp with no fluctuation in light output can be obtained.

FIG. 23 is a graph showing the results of investigating the deformation of the arc tube and the occurrence of devitrification by measuring the change in the inner diameter of the arc tube similarly to FIG. The horizontal axis and the vertical axis in FIG. 23 are the same as those in FIG.

As can be seen from FIG. 23, even when the magnetic field is constant and the distance between the electrode tips is 6.0 (mm), the change in the inner diameter of the arc tube 1 is 10 BW as in the first embodiment. / F-P · d. 10 BW / f-
When the value of P · d was less than 0, the change in the inner diameter of the arc tube exceeded about 5 (%). At this time, a change in the arc position occurs, the luminous flux is reduced to 70% or less with respect to the initial luminous flux, and the change in color temperature exceeds 300 (K). Was confirmed.
Also, although the change in the inner diameter of the arc tube is small, 10 BW / f
When the value of −P · d was less than 2, devitrification was observed in the upper part of the arc tube.

Therefore, by defining the range of 10 BW / f−P · d to be more than 0, it is possible to realize a mercury-free high-intensity discharge lamp with less deformation of the arc tube and excellent life characteristics. If 10BW / f-P · d is specified in the range of more than 2, it is possible to obtain a mercury-free high-intensity discharge lamp having not only a small arc tube deformation, but also suppressed devitrification and more excellent life characteristics. More preferable.

Next, the distance d between the tips of the pair of electrodes 3, 3
Mercury-free high-intensity discharge lamp lighting device 1 with 8 mm
No. 00 was produced, and flicker and life characteristics were evaluated. As with Embodiment 1, 0 <10 BW / f−P · d <
Within the range of 10, it was possible to realize a mercury-free high-intensity discharge lamp lighting device having no flicker and excellent life characteristics. However, in this case, the starting voltage is 30
The result exceeded (kV). Since the size of a drive circuit that generates a starting voltage exceeding 30 (kV) becomes large, it is more preferable that the value of d is less than 8, that is, the value of P · d is less than 8.

Further, even if the value of d is 6 mm, it is possible to realize a mercury-free high-intensity discharge lamp lighting device which is free from flicker and has excellent life characteristics. However, in this case, the result was that the starting voltage exceeded 25 (kV). 25 (k
V) or less, the driving circuit can be made smaller by limiting the starting voltage, so that the value of d is 6 or less.
It is more preferable that the value is less than (mm), that is, the value of P · d is less than 6. (Embodiment 4) In Embodiment 4, the above Embodiments 1 to 3 are used.
An example of a lighting system including the high-intensity discharge lamp according to the present invention will be described.

FIG. 24 is a schematic diagram showing the structure of a lamp with a mirror (lighting system) including the high-intensity discharge lamp 11 of the above embodiment, a lighting circuit 12, and a reflecting mirror 80 that reflects the light emitted from the lamp 11. It is shown in the figure. It is arranged so that the center of the arc of the lamp 11 is located on the optical axis of the reflecting mirror 80. The straight line connecting the tips of the pair of electrodes 3 and 3 is attached to the reflecting mirror 80 so as to be horizontal. In that state, the lamp 11
Are connected to the lighting circuit 12.

By adopting the configuration shown in FIG. 24,
It is possible to effectively project the light from the arc and realize an efficient mercury-free high-intensity discharge lamp lighting device (lighting system). In addition, as described above, (10
By defining the downward force F2 according to the term of BW / f) and the upward force F1 according to the term of P · d, it becomes possible to control the arc position in the high-intensity discharge lamp. A system capable of changing the light distribution characteristic of light can be easily realized. (Fifth Embodiment) As described above, in consideration of the global environment at the time of disposal, a metal halide lamp containing no mercury is desired. However, in a metal halide lamp containing mercury, In (indium) halide is used. An enclosed metal halide lamp is preferably used. In is
It has excellent light emission characteristics and ELECTRIC DISCHERGE LAMPS
As shown in (P218, JOHN F.WAYMOUTH), the effect of thickening the arc and stabilizing the arc is known.

The inventor of the present application made a prototype of a mercury-free metal halide lamp in which mercury was removed from the Sc—Na-based mercury-containing metal halide lamp, and examined the characteristics. As a result, it was confirmed that the expected light emission characteristics could not be obtained. . Therefore,
A metal halide lamp that does not contain mercury, which has excellent light emission characteristics and is known to have the effect of stabilizing the arc, was added and was prototyped. The structure of this metal halide lamp is the same as that shown in FIG. 1 except for the enclosure 6.

Here, the distance d between the electrodes is about 4.2 (mm).
The xenon gas filling pressure at 20 ° C is 1.4 (M
Pa). The inner volume of the arc tube 1 is about 0.025.
(Cc), in which about 0.1 mg of +3 valent indium iodide InI ₃ (about 4.2 mg / cc per unit inner volume of the arc tube) and about 0.19 mg of scandium iodide (unit: About 8.0 mg / c per volume of arc tube
The halide 6 composed of c) and about 0.16 mg of sodium iodide (about 6.4 mg / cc per unit inner volume of the arc tube) is enclosed. Of course, the arc tube 1 does not contain mercury.

The mercury-free metal halide lamp was arranged and lit so that the straight line connecting the electrode tips of the lamp was in the vertical direction (hereinafter, this lighting is referred to as "vertical lighting"). However, by adding In, rather than stabilizing the arc, the arc became unstable in this mercury-free metal halide lamp. In other words, the arc was not stationary, and the light output of the lamp became unstable. Therefore, it has been found that there is a problem in that flicker is visually observed.

Next, the mercury-free metal halide lamp was lit by arranging the lamp so that the straight line connecting the electrode tips of the lamp was in the horizontal direction (hereinafter, this lighting is called "horizontal lighting"). However, the arc contacted the inner surface of the arc tube and became stable. However, even if it is stable, when the arc and the inner surface of the arc tube are in contact with each other, the contacted part expands, leading to rupture of the arc tube. Therefore, it is impossible to use the lamp when the arc is in contact with the inner surface of the arc tube and is stable. Therefore, a magnetic field was applied in order to apply a downward force F2 of the arc based on the knowledge of the inventor of the present application, and lighting was performed so as to eliminate contact between the arc and the inner surface of the arc tube. Became unstable. As a result, the light output of the lamp became unstable, and it became flickering to the eye.

Such a phenomenon cannot occur in a conventional metal halide lamp containing mercury if In having an arc stabilizing effect is enclosed as a light emitting metal. However, in a metal halide lamp containing no mercury, the arc becomes unstable when In is sealed. That is, a phenomenon that cannot be predicted occurs from the conventional metal halide lamp containing mercury.

The present inventor succeeded in stabilizing the mercury-free metal halide lamp containing In by controlling the upward force (buoyancy) F1 in the arc tube 1 and contained In which stabilized the arc. A mercury-free metal halide lamp has been realized.

Hereinafter, referring to FIGS. 25 to 27,
The mercury-free metal halide lamp according to this embodiment will be described.

The mercury-free metal halide lamp of this embodiment has the lamp structure shown in FIG. 1, but the distance between the electrodes is d (mm) and the enclosed rare gas pressure at 20 ° C. is P (MP.
In the case of a), the enclosed rare gas pressure and the distance between the main electrodes are defined so as to satisfy Pd ≦ 4.6. In this embodiment, the inter-electrode distance d is set to about 4.2 (mm), and the xenon gas filling pressure at 20 ° C. is set to 1.4 (MPa). In this embodiment, the auxiliary electrode for facilitating the lighting of the lamp is not provided, but the auxiliary electrode may be provided. The configuration provided with the auxiliary electrode is not limited to this embodiment,
You may employ | adopt also in the said Embodiment 1-4. It goes without saying that the inter-electrode distance d when the auxiliary electrode is provided may be the distance between the main electrodes excluding the auxiliary electrode.

In the present embodiment, the distance between the tips of the electrodes 3 in the arc tube 1, that is, the distance d between the electrodes is about 4.2.
(Mm). The inner volume of the arc tube 1 is about 0.025.
(Cc), in which about 0.1 mg of +3 valent indium iodide InI ₃ (about 4.2 mg / cc per unit inner volume of the arc tube) and about 0.19 mg of scandium iodide (unit: About 8.0 mg / c per volume of arc tube
The halide 6 composed of c) and about 0.16 mg of sodium iodide (about 6.4 mg / cc per unit inner volume of the arc tube) is enclosed. Although not shown,
Inside the arc tube 1, at room temperature (20 ° C.), 0.3 MPa (megapascal), 0.7 MPa, 1.0 MPa, 1.1 MP
a, four types of lamps filled with 1.4 MPa Xe gas were prototyped, a rectangular wave current of 150 Hz was supplied to these prototype lamps, and the lamp power was 35 W for vertical lighting.

In order to quantify the instability (flicker) of the arc, a change in the light output was observed with the illuminance meter 40 and a flicker was observed with the monitor 70 in the configuration shown in FIG. In addition, in both the present embodiment and the first embodiment, the distance between the measurement head 42 and the lamp 11 is 32 cm.

The results are shown in FIG. The horizontal axis of FIG. 25 represents P × d (MPa · mm), and the vertical axis represents the fluctuation of the optical output. Also in this embodiment, the fluctuation of the optical output is
A value obtained by dividing the difference between the maximum value and the minimum value of the light output by the average value of the light output is shown in%.

As can be seen from FIG. 25, the fluctuation of the light output of the lamp 11 depends on P × d. P × d is 2.9
Fluctuations began to occur when the number exceeded 4. Furthermore, P × d is 4.
Above 6 the fluctuations in light output exceeded 6%. At this time, the subject felt flicker.

Therefore, by defining P × d to be 4.6 or less, it is possible to realize a mercury-free metal halide lamp without flicker. Pxd is 2.94
Not only will you not feel the flicker if you specify below,
It is more preferable because it can be a mercury-free metal halide lamp with no fluctuation in light output.

Next, the Xe pressure was set to 1.0 MPa (constant) at room temperature, the distance d between the electrodes was 2.0 mm, 4.2 mm, and 4.6 m in the same structure as the above-described mercury-free metal halide lamp.
The instability (flicker) of the arc was quantified also for the lamp 11 which was changed to m and 5.0 mm. Similarly, this lamp 11 was supplied with a rectangular wave current of 150 Hz and vertically lit with a lamp power of 35 W. The result is shown in FIG. As in FIG. 25, the horizontal axis of FIG. 26 represents P × d, and the vertical axis thereof represents the fluctuation of optical output.

As can be seen from FIG. 26, the fluctuation of the light output of the lamp 11 depends on P × d. P × d is 4.6
At higher frequencies, the fluctuation of the light output exceeded 6%, and the fluctuation of the light output was about 6 to 10 Hz. At this time, the subject felt flicker.

Therefore, by defining P × d to be 4.6 or less, it is possible to realize a mercury-free metal halide lamp without flicker. From the above,
Noble gas (Xe) pressure P (MPa) and electrode distance d (mm)
It is understood that by setting Pd ≦ 4.6, it is possible to realize an In-free silver halide metal halide lamp that does not cause flicker.

The principle of arc bending and the study by the inventor of the present application will be described, although it may be the same as that described in the above embodiment.

Normally, when the metal halide lamp is turned on, the arc bends upward due to the effect of buoyancy due to the temperature distribution generated in the arc tube. From this, the inventor of the present application considered that the flicker (arc instability) at the time of lighting with a metal halide lamp containing no mercury depends on the magnitude of buoyancy. However, it was considered that the buoyancy applied to the arc does not depend only on the temperature distribution but also on the relationship with the pressure of the rare gas filled in the arc tube and the distance between the electrodes.

Therefore, a model as shown in FIG. 27 was considered. Hereinafter, the relational expression of the buoyancy applied to the arc, the gas density, and the arc length will be obtained.

The buoyancy force F ₁ applied to the arc is F ₁ = πl ² d (ρ _w −ρ _a ) g (Equation 8) (In Equation 8, ρ _{w is} the gas density near the tube wall, ρ _a : Gas density in arc, l: effective radius of arc, g: gravity,
d: Arc length) Next, assuming that the gas temperature of the arc is T _a (constant) and the gas temperature near the tube wall is T _w (constant), the equation 8 can be transformed as follows.

[0169] In ^{_{F 1 = πl 2 dρ a {}} (T w -T a) / T a} g ··· ( Formula 9) In this embodiment, [rho _w was varied approximately 5-fold. Therefore, since the term change of (T _w −T _a ) / T _a is small,
It is possible to ignore changes in the term (T _w −T _a ) / T _a . Therefore, it can be seen from Equation 9 that there is a relationship of F ₁ ∝ρ _a d ... (Equation 10). Note that ρ _a can be regarded as the gas pressure and d can be regarded as the distance between the electrodes. Therefore, it can be seen from the proportional expression of Expression 10 and the experimental result that the arc becomes unstable as the buoyancy (P × d) increases. Therefore, by defining the value of P × d of the lamp so that the arc is not unstable, a mercury-free metal halide lamp without flicker can be realized.

Next, another configuration of this embodiment will be described.
FIG. 28 shows a mercury-free metal halide lamp having this structure. The mercury-free metal halide lamp shown in FIG.
The difference is that the magnetic field is applied by.

As shown in FIG. 28, the permanent magnet 10 is arranged so that the direction of the magnetic field B in the portion between the electrode tips is the vertical direction. The strength of the magnetic field between the electrode tips is 5.0 to 1
It is 0.0 (mT) and the distance d between the electrodes is 4.6 mm. Although not shown, the Xe pressure in the arc tube 1 is 1.0.
(MPa) and 1.4 (MPa) were changed to manufacture a lamp. 150H for each of these prototype valves
A rectangular wave current of z was supplied and the lamp was turned on horizontally with a power of 35 W.

In order to quantify the instability (flicker) of the arc, a change in the light output was observed by the illuminance meter 40 and a flicker was observed by the monitor 70 in the configuration shown in FIG. The result is that it depends on P × d, and when P × d is higher than 4.6, the fluctuation of the optical output exceeds 6%.
At this time, the test subject felt flicker. Therefore,
By defining P × d to be 4.6 or less, it is possible to realize a mercury-free metal halide lamp without flicker.

From the above, flicker is felt by setting the rare gas (Xe) pressure P (MPa) and the interelectrode distance d (mm) to Pd ≤ 4.6 in both vertical lighting and horizontal lighting. No mercury-free metal halide lamp can be realized.

When the mercury-free metal halide lamp of the present embodiment is used for a vehicle headlight, an instant light rise is required immediately after starting, and the light emission immediately after starting is mainly due to the rare gas (Xe). Xe because it is based
The pressure P (MPa) is preferably 0.3 (MPa) or more.
Moreover, 0.5 (MPa) or more is more preferable.

When used for a vehicle headlight, the lamp voltage is proportional to the arc length d (mm). Therefore, if the arc length is too short, an appropriate lamp voltage, for example, 60 to 70 V can be obtained. Sometimes there is not. Therefore, the arc length d is preferably 2 mm or more, more preferably 3 mm or more.

As described in the first embodiment,
Also in the present embodiment, the constituent elements such as the xenon gas pressure, the inner volume of the arc tube 1 other than the distance between the electrodes, the amounts of scandium iodide and sodium iodide, etc. are merely examples. Therefore, for example, the inner volume of the arc tube 1 is 0.025c.
The amount of scandium iodide is not limited to 0.19 mg. Further, although xenon gas is enclosed in the arc tube 1 for the purpose of assisting the starting, the xenon gas is only suitable as the rare gas in consideration of the use in the vehicle headlight, and the rare gas is other than xenon gas. Noble gas such as argon gas may be used. Similarly, the lamp power is not limited to 35W.

The mercury-free metal halide lamp of this embodiment can also have the structure of the lamp with a mirror shown in the fourth embodiment. Further, the ones shown in the first to fifth embodiments can be used not only for automobile headlights but also for general lighting and other applications. For example, it can be used as a light source for an image projection apparatus such as a projector using liquid crystal or DMD. Furthermore, it can also be used for competition stadiums and for floodlights that illuminate road signs.

[0178]

According to the present invention, between the tips of a pair of electrodes
The magnetic field applied to the center is B (mT), and
The distance between the tips is d (mm), and the above-mentioned light emission during steady lighting
The pressure inside the pipe is P₀(MPa) and consumed during steady lighting
The power that is generated is W (W), and the stable frequency during steady lighting is
When f (Hz), 0 <(100BW / f) -P
₀Since the relationship of d <100 is satisfied, the fluctuation of the arc
-Free high-intensity mercury-free discharge lamp that suppresses flicker
A lighting device can be provided.

According to the mercury-free metal halide lamp of the present invention, when the distance between the tips of the pair of electrodes is d (mm) and the pressure of the rare gas at room temperature is P (MPa), Pd ≦ Since it is set to 4.6, the fluctuation of the arc can be suppressed and the flicker can be prevented.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing the structure of a metal halide lamp.

FIG. 2 is a cross-sectional view showing a state in which an arc is bent upward.

3 (a) and 3 (b) are cross-sectional views showing a configuration in which a permanent magnet 10 is arranged in a lower portion or an upper portion of the arc tube 1. FIG.

FIG. 4 is a diagram modeling a configuration around an arc in order to explain an upward force F1 applied to the arc.

FIG. 5 is a graph showing a relationship between an arc bending amount and a BW / f relationship.

FIG. 6 is a graph showing the pressure inside the arc tube 1 when the lamp is lit.

FIG. 7 is a diagram showing a configuration of a mercury-free high-intensity discharge lamp lighting device 100 according to Embodiment 1 of the present invention.

FIG. 8 is a cross-sectional view schematically showing the configuration of a high-intensity discharge lamp 11 included in the lamp lighting device 100.

FIG. 9 is a configuration diagram of an experimental apparatus used for measuring light output fluctuation.

FIG. 10 is 10 when the magnetic field B is 4.0 (mT).
It is a graph which shows the relationship between BW / fPd and optical output fluctuation.

FIG. 11 is 10 when the magnetic field B is 4.0 (mT).
It is a graph which shows the relationship between BW / f-P * d and an arc tube inner diameter change rate.

FIG. 12: 10B when the magnetic field B is 40 (mT)
Graph showing the relationship between W / fPd and optical output fluctuation

FIG. 13: 10B when the magnetic field B is 40 (mT)
It is a graph which shows the relationship between W / f-P * d and an arc tube inner diameter change rate.

FIG. 14 is 10 when the magnetic field B is 400 (mT).
It is a graph which shows the relationship between BW / fPd and optical output fluctuation.

FIG. 15 is 10 when the magnetic field B is 400 (mT).
It is a graph which shows the relationship between BW / f-P * d and an arc tube inner diameter change rate.

FIG. 16: The filling pressure of noble gas at 20 (° C.) is 0.1 (M
6 is a graph showing the relationship between 10 BW / fPd and the light output fluctuation in the case of (Pa).

FIG. 17: The filling pressure of noble gas at 20 (° C.) is 0.1
It is a graph which shows the relationship between 10 BW / f-P * d and the arc tube inner diameter change rate in the case of (MPa).

FIG. 18: The filling pressure of noble gas at 20 (° C.) is 2.5.
It is a graph which shows the relationship between 10 BW / fPd and optical output fluctuation in the case of (MPa).

FIG. 19: The filling pressure of noble gas at 20 (° C.) is 2.5.
It is a graph which shows the relationship between 10 BW / f-P * d and the arc tube inner diameter change rate in the case of (MPa).

FIG. 20 is a graph showing the relationship between 10 BW / fPd and the optical output fluctuation when the distance d between the electrode tips is 2.0 (mm).

FIG. 21 is a graph showing the relationship between 10 BW / fPd and the arc tube inner diameter change rate when the distance d between the electrode tips is 2.0 (mm).

FIG. 22 is a graph showing a relationship between 10 BW / f−P · d and optical output fluctuation when the distance d between the electrode tips is 6.0 (mm).

FIG. 23 is a graph showing the relationship between 10 BW / fPd and the arc tube inner diameter change rate when the distance d between the electrode tips is 6.0 (mm).

FIG. 24 is a diagram showing a configuration of a mercury-free high-intensity discharge lamp lighting device (lamp with mirror) according to a fourth embodiment.

FIG. 25 is a graph showing the relationship between the light output fluctuation and P × d when the mercury-free metal halide lamp according to the fifth embodiment is vertically lit at a power of 35 W with respect to Xe pressure.

FIG. 26 is a graph showing the relationship between the interelectrode distance and the light output fluctuation when the mercury-free metal halide lamp according to the fifth embodiment is vertically lit at a power of 35 W.

FIG. 27 is a model diagram for obtaining a relational expression of buoyancy, gas density and arc length.

FIG. 28 is a sectional view schematically showing another configuration of the mercury-free metal halide lamp according to the fifth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 arc tube 2 sealing part 3 electrode 4 molybdenum foil 5 lead wire 6 halide 7 arc 9 AC power supply 10 magnetic field applying means (permanent magnet) 11 high-intensity discharge lamp (silver-free metal halide lamp) 12 lighting circuit 13 base 14 outer tube 20 Filter 40 Illuminometer 41 Oscilloscope 50 CCD 60 VTR 70 Monitor 80 Reflector 100 Mercury-free high-intensity discharge lamp lighting device

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor ▲ Yoshi ▼ Masato Ta 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takayuki Murase 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Inventor Ryo Minamihata 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor, Mamoru Takeda 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (56 ) References JP-A-11-307048 (JP, A) JP-A 1-215639 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01J 61/50 H01J 61/16 H01J 61/20 H05B 41/02 H05B 41/231

Claims (10)

(57) [Claims] 1. A high-intensity discharge lamp which has a light emitting tube in which a pair of electrodes are arranged in a tube in which a light emitting substance is enclosed, and an alternating current generating means for supplying an alternating current to the pair of electrodes. And a lighting circuit that includes a lighting circuit that includes, in the arc tube, mercury as the luminescent substance is not included, and a magnetic field including a component that is substantially perpendicular to a straight line connecting the tips of the pair of electrodes is substantially vertical. A magnetic field applying means for applying a magnetic field in a direction, wherein the magnetic field applied to the center between the tips of the pair of electrodes is B (mT), and the distance between the tips of the pair of electrodes is d.
(Mm), and the pressure inside the arc tube during steady lighting is P
₀ (MPa), and the power consumed during steady lighting is W
(W) and a stable frequency during steady lighting is f (Hz), the relationship of 0 <(100BW / f) −P ₀ d <100 is satisfied, and a mercury-free high-intensity discharge lamp is provided. Lighting device. 2. A high-intensity discharge lamp which has a light-emitting tube in which a pair of electrodes are arranged in a tube in which a light-emitting substance is sealed, and which is horizontally lit, and an alternating current generating means for supplying an alternating current to the pair of electrodes. A lighting circuit including, wherein the arc tube does not contain mercury as the luminescent material, and contains at least a rare gas, with respect to a straight line connecting the tips of the pair of electrodes. A magnetic field applying unit that applies a magnetic field including a substantially vertical component in a substantially vertical direction is further provided, and the magnetic field applied to the center between the tips of the pair of electrodes is B (mT), and the tips of the pair of electrodes are provided. The distance between
(Mm) and the filling pressure of the rare gas at 20 ° C. is P
(MPa) and the power consumed during steady lighting is W
(W) and the stable frequency during steady lighting is f (Hz), the relationship of 0 <(10BW / f) -Pd <10 is satisfied, and a mercury-free high-intensity discharge lamp lighting device is characterized. . 3. The filling pressure P is 0.1 (MPa) <
The mercury-free high-intensity discharge lamp lighting device according to claim 2, wherein P <2.5 (MPa). 4. The filling pressure P and the distance d are P
The mercury-free high-intensity discharge lamp lighting device according to claim 2, wherein the relationship of d <8 is satisfied. 5. The filling pressure P and the distance d are P
5. The relationship of d ≦ 4.6 is satisfied, and the relationship is d4.
1. A mercury-free high-intensity discharge lamp lighting device according to. 6. The lighting frequency f during the steady lighting is 40
The mercury-free high-intensity discharge lamp lighting device according to claim 1, wherein (Hz) <f. 7. The mercury-free high-intensity discharge lamp lighting device according to claim 1, wherein the magnetic field B is in a range of B <500 (mT). 8. The distance d between the tips of the pair of electrodes.
Is a range of 2 <d (mm), The mercury-free high-intensity discharge lamp lighting device according to any one of claims 1 to 7. 9. The high-intensity discharge lamp is a metal halide lamp containing at least indium halide as the luminescent material in the arc tube.
1. A mercury-free high-intensity discharge lamp lighting device according to any one of 1. 10. A reflecting mirror for reflecting light emitted from the high-intensity discharge lamp, wherein the arc center of the mercury-free high-intensity discharge lamp is arranged on the optical axis of the reflecting mirror. A mercury-free high-intensity discharge lamp lighting device according to any one of claims 1 to 9.