JP2004171833A - High-pressure discharge lamp, high-pressure discharge lamp lighting device, and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp equipped with a small translucent ceramic discharge vessel suitable for collection of light; and to provide a high-pressure discharge lamp lighting device and a lighting system using it. <P>SOLUTION: This high-pressure discharge lamp HPDL is equipped with the translucent ceramic discharge vessel 1 with both ends opened; a pair of metal pipes 2, 2 used for closing both the ends of the discharge vessel 1 by inserting their opening parts on the tip sides into the ends of the discharge container 1 to be sealed, and facing to each other at a distance L<SB>M</SB>between the tips with base end sides exposed to the outside of the discharge vessel 1 and sealed; a pair of electrodes 3, 3 having base end parts each connected to and supported by the sealed part of the base end side 2b of the metal pipe 2, and having tip parts facing to each other at a distance G and projecting in the discharge vessel 1; and a discharge medium enclosed in the discharge vessel 1. The ratio of the distances G/L<SB>M</SB>satisfies G/L<SB>M</SB><0.85. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure discharge lamp provided with a translucent ceramic discharge vessel, a high-pressure discharge lamp lighting device using the same, and a lighting device.
[0002]
2. Description of the Related Art A technique relating to a metal halide small high-pressure discharge lamp using a translucent ceramic and having a lamp power of about 20 W has been developed and is already in practical use.
[0003]
On the other hand, Patent Literature 1 discloses a technique of heating and melting both a metal lead and a metal pipe connected to an electrode mandrel in FIGS. 9 and 10. Also, a joined body for joining a first member made of ceramics or cermet and a second member made of metal by interposing a main phase contacting the first member and an intermediate glass member contacting the second member. Wherein the intermediate glass member is in contact with the second member and is present between the second member and the main phase, the main phase having an opening, made of a sintered body of metal powder, and It is described that it is constituted by a porous skeleton structure in which the opening is impregnated with a glass phase.
[0004]
Further, Patent Document 2 discloses a high-pressure discharge lamp in which both ends of a translucent ceramic discharge vessel are closed with a metal pipe and a base end of an electrode is welded to a base end of the metal pipe. The pipe is sealed as an exhaust pipe, and the ratio between the maximum outer diameter of the surrounding portion of the translucent ceramic discharge vessel and the overall length of the high-pressure discharge lamp is optimized, so that it is small but has high luminous efficiency and / or desired emission color. Are described.
[0005]
Further, Patent Document 3 discloses that the shortest distance between the inner surface of a bulb made of translucent ceramics and an electrode coil is 0.6 mm in order to prevent thermal stress cracking in the arc tube part of the bulb at the time of starting. A ceramic discharge lamp in which the maximum thickness of the arc tube part is 1.2 mm or less is described.
[0006]
[Patent Document 1]
EP 0 982 278 A1 (Japanese Patent Laid-Open No. 2001-58882)
[Patent Document 2]
JP-A-2002-245971
[Patent Document 3]
JP-A-11-204086
However, the translucent ceramic discharge vessel using the metal pipes described in Patent Documents 1 and 2 has a structure suitable for a small high-pressure discharge lamp. Manufactured a similar high-pressure discharge lamp and conducted additional tests. It was found that glow discharge occurred between the metal pipes at startup depending on the design conditions. In such a case, transition from glow discharge to arc discharge becomes impossible.
[0007]
On the other hand, high-pressure discharge lamps using a translucent ceramics discharge vessel have been recognized and valued as high-efficiency, long-life light sources in high-pressure sodium lamps and metal halide lamps. Polycrystalline alumina ceramics are generally used for translucent ceramics discharge vessels used in these high-pressure discharge lamps. Polycrystalline translucent ceramics have the common feature that the total transmittance is high but the linear transmittance is low. Therefore, since the radiated light from the lighting arc is diffused when transmitting through the translucent ceramics discharge vessel, the translucent ceramics discharge vessel becomes the size of the light source.
[0008]
High-pressure discharge lamps also have light-collecting applications such as projection and automotive headlights.In such applications, the linear transmission is high, so the size of the arc is limited by the size of the light source. In other words, since the light source can be further miniaturized, a single-crystal light-transmitting ceramic is more advantageous than a polycrystalline light-transmitting ceramic.
[0009]
Since a single-crystal translucent ceramic does not have a crystal grain boundary, its thermal conductivity is higher than that of a polycrystalline ceramic. In addition, single-crystal translucent ceramics are generally manufactured by a pulling method, and thus can be formed in a cylindrical shape. However, a spherical or elliptical-like shape suitable for a discharge vessel is used. It is extremely difficult to mold the material into
[0010]
When the discharge vessel is cylindrical, there is a problem that the temperature gradient of the discharge vessel becomes larger as compared with a spherical shape, and cracks are likely to occur due to thermal stress due to the temperature difference between the inner and outer surfaces. Patent Literature 3 solves this problem, but Patent Literature 3 relates to a translucent ceramic having a spherical shape and a polycrystalline transmissive ceramic. This is a conductive ceramic and is different from a cylindrical discharge vessel. As described in the document, the ceramic discharge lamp of Patent Document 3 has a maximum outer diameter of 8.7 to 11.0 mm and an inner volume of 0.4 to 0.75 cm. ³ The rated lamp power is estimated to be used for relatively large general lighting of about 50 to 100 W. Furthermore, in the ceramic discharge lamp of Patent Document 3, the discharge vessel is formed integrally with a sealed tube portion having an outer diameter of 2.0 to 2.6 mm and an inner diameter of 0.6 to 1.0 mm at both ends of the arc tube portion. The structure is 34 to 40 mm in total length. The problem of thermal stress in the discharge vessel of a high-pressure discharge lamp has different aspects depending on the size and structure of the discharge vessel.
[0011]
SUMMARY OF THE INVENTION It is a general object of the present invention to provide a high-pressure discharge lamp provided with a small-sized translucent ceramics discharge vessel suitable for condensing, a high-pressure discharge lamp lighting device and a lighting device using the same.
[0012]
In addition, the present invention further provides a high-pressure discharge lamp which facilitates glow-arc transition while having a translucent ceramics discharge vessel sealed by inserting metal pipes into both ends of the opening, and a high-pressure discharge lamp using the same. It is a specific object to provide a device and a lighting device.
[0013]
Further, the present invention provides a high-pressure discharge lamp in which thermal stress is reduced in a single-crystal, translucent ceramic discharge vessel having a straight tubular shape, a high-pressure discharge lamp lighting device and a lighting device using the same. For other purposes.
[0014]
[Means for achieving the object]
The high-pressure discharge lamp according to the first aspect of the present invention is a high-pressure discharge lamp having a translucent ceramic discharge vessel having both ends opened; Both ends of the conductive ceramic discharge vessel are closed, and the distance L between the tips is _M A pair of metal pipes whose base ends are exposed to the outside of the translucent ceramics discharge vessel and are sealed, and a base end is connected to a sealing part on the base end of the metal pipe. A pair of electrodes supported and protruding in the translucent ceramics discharge vessel at opposite ends at a distance G; and a discharge medium sealed in the translucent ceramics discharge vessel. Ratio G / L _M Satisfy Expression (1).
[0015]
(Equation 1)
G / L _M <0.85
In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.
[0016]
<Regarding Translucent Ceramic Discharge Vessel> “Translucent ceramics discharge vessel” refers to single-crystal and polycrystalline metal oxides such as hermetic aluminum oxide, yttrium-aluminum-garnet (YAG), and yttrium oxide. (YOX) and a discharge vessel made of a material having light transmittance and heat resistance such as a polycrystalline non-oxide such as aluminum nitride (AlN). Single crystal aluminum oxide is called sapphire. Note that the term “light-transmitting” means light-transmitting to the extent that light generated by discharge can be transmitted to the outside, and may be not only transparent but also light-diffusing. It is sufficient that at least a portion surrounding the discharge space, that is, the surrounding portion has a light-transmitting property. If necessary, if a supplementary structure other than the surrounding portion is provided, the portion may be light-shielding.
[0017]
However, since single-crystal translucent ceramics are transparent, by providing a translucent ceramic discharge vessel using this, the size of the light source can be reduced to the size of the arc, so that high light collection is achieved. Since efficiency is obtained, it is suitable as a high-pressure discharge lamp for condensing light. In addition, single-crystal translucent ceramics have higher thermal conductivity than polycrystalline translucent ceramics, so the thermal stress generated between the inner and outer surfaces is reduced, and the discharge vessel caused by the thermal stress is reduced. Cracks are less likely to occur. Among the single-crystal translucent ceramics, sapphire has relatively high thermal conductivity, so that one having less thermal stress, colorless and transparent, and having a high linear transmittance of 80 to 90% can be easily used. Since it can be obtained, it is most suitable as a translucent ceramics discharge vessel. The thermal conductivity of aluminum oxide is 42 W / m · K for single crystal sapphire and 36.7 W / m · K for polycrystalline alumina ceramics.
[0018]
Also, the translucent ceramics discharge vessel generally allows for various shapes. In the case of using a polycrystalline translucent ceramic, since molding is relatively easy, a spherical-like or cylindrical surrounding portion and a sealing portion having a smaller outer diameter than the surrounding portion are formed by integral molding or shrink fitting. Provided shapes can be employed. In the shrink fitting method, for example, the surrounding portion and the additional structure portion for sealing are temporarily sintered separately and then joined as required, and the whole is sintered to form an integrated light-transmitting portion. This is a method for forming a conductive ceramic discharge vessel. On the other hand, in the case of single-crystal translucent ceramics, single-crystal growth is mainly performed by the pulling method, so that a straight tubular material can be obtained relatively easily. It is preferable that the surrounding portion surrounding the discharge space and the sealing portions at both ends have the same diameter by using the straight tubular material as it is.
[0019]
Further, the size of the translucent ceramics discharge vessel is not generally limited. However, in the case of an automobile headlight made of a single crystal translucent ceramics, the outer diameter is 1.5 to 5.0 mm. Even more preferably, 2.5 to 4.0 mm, inner diameter is 0.4 to 3.0 mm, still more preferably 1.0 to 2.5 mm, total length is 10 to 40 mm, still more preferably 20 to 30 mm. In the case of a projector device, the outer diameter is 5 to 20 mm, preferably 5 to 10 mm, the inner diameter is 3.0 to 10 mm, more preferably 3.0 to 50 mm, and the total length is 20 to 60 mm. Even more preferably, it is 30 to 50 mm.
[0020]
<Regarding the metal pipe> The metal pipe has at least an open end, and the end is inserted into the openings at both ends of the translucent ceramics discharge vessel to hermetically close the end to discharge the translucent ceramics discharge. Seal the container and support the electrodes. A pair of metal pipes inserted into both ends of the translucent ceramic has a distance between the ends L, which sandwiches the translucent ceramic discharge vessel. _M Facing each other. Note that the distance L _M Is set so that a ratio with a distance G between a pair of electrodes described later is within a predetermined value range. More specifically, the metal pipe has an opening on the distal end side, the base end side is sealed (this point will be described later), and the opening on the distal end side is the end of the transparent ceramic discharge vessel. The translucent ceramics discharge vessel is sealed by being inserted into the portion, and the inserted portion and the inner surface of the end portion of the translucent ceramics discharge vessel facing the portion are sealed by an appropriate means. I have. On the other hand, the base end side of the metal pipe is exposed to the outside from the translucent ceramics discharge vessel.
[0021]
As understood from the above structure, the metal pipe is in a state in which the inside communicates with the inside of the translucent ceramic discharge vessel, so that it is fire-resistant and has corrosion resistance not corroded by the discharge medium. Preferably, it is made of a refractory metal whose coefficient of thermal expansion is relatively close to that of the translucent ceramics discharge vessel. For example, in the case of a translucent ceramic discharge vessel made of aluminum oxide, molybdenum is optimal, but tungsten may be used.
[0022]
In order to seal the metal pipe to the translucent ceramic discharge vessel, a cermet or a combination of a cermet and a compound for sealing a ceramic can be used. As the latter configuration, for example, the technology disclosed in Patent Document 1 can be used.
[0023]
On the other hand, the base end of the metal pipe may have any sealing structure. For example, the base end of the metal pipe can be pinched and pressed and welded, or the base end can be melted to directly seal. Further, the base end of the metal pipe may be sealed via a fusion metal. The term "fused metal" refers to a metal that can be hermetically fused to a metal pipe, and does not mean a specific type of metal. It is preferable to use a metal having a fire resistance enough to withstand a temperature rise during normal operation of the metal pipe and having a coefficient of thermal expansion close to the coefficient of thermal expansion of the metal pipe. For example, platinum or an alloy of platinum and molybdenum is suitable.
[0024]
<Regarding a pair of electrodes> The pair of electrodes has a base end connected to and supported by a sealing portion on the base end side of the metal pipe, and a tip end protruding into the surrounding portion of the translucent ceramic discharge vessel. This forms a distance G between the electrodes. The specific distance between the electrodes G is not particularly limited, but is preferably 1.0 to 8.0 mm, more preferably, for an automotive headlight made of a single crystal translucent ceramic. Is preferably set to 2.0 to 5.0 mm, and in the case of a projector device, is preferably set to 0.5 to 2.0 mm, more preferably 0.5 to 1.5 mm. The distance G (mm) between the electrodes and the distance L between the tips of the metal pipes described above. _M Will be described later. In addition, any structure may be used to connect the base end of the electrode to the sealing portion of the metal pipe.
[0025]
The electrode generally has an electrode shaft portion and an electrode main portion, but the electrode shaft portion in such a configuration has an elongated rod shape, and has a base end portion and an intermediate portion of the electrode. Is composed. The electrode shaft can be formed by using a conductive material such as tungsten, doped tungsten, or molybdenum and using a refractory substance alone or in an appropriate combination. On the other hand, the electrode main part is a part disposed at the tip of the electrode shaft and mainly acting as a cathode and / or an anode, and constitutes the tip of the electrode. Further, the electrode main portion can be formed using tungsten, doped tungsten rhenium, a tungsten-rhenium alloy, or the like as a material. In the case of a small high-pressure discharge lamp having a lamp power of 50 W or less, preferably about 35 W, used for an automobile headlight or the like, the tip of the electrode shaft can be used as the electrode main part as it is. In the case of a small high-pressure discharge lamp having a lamp power of 100 W or less, such as for a projector device, a tungsten coil can be wound as necessary to increase the surface area and improve heat dissipation.
[0026]
Further, the pair of electrodes has a symmetric structure in the case of an AC lighting type, but can have an asymmetric structure in the case of a DC lighting type.
[0027]
<About Discharge Medium> As the discharge medium, it is preferable to use a luminescent substance, a lamp voltage forming medium and a rare gas in the following combinations, for example. Note that as the light-emitting substance, a rare gas and / or a metal vapor can be used. The metal vapor can be encapsulated as a luminescent metal emitting visible light, an alloy thereof, or a halide of these metals. As the lamp voltage forming medium, mercury or a metal halide described later can be mainly used. Mercury is contained in 3. In this case, it also contributes as a luminescent metal. As the halide as a lamp voltage forming medium, a metal having a relatively high vapor pressure during lighting and emitting relatively little light in the visible region, for example, a halide such as Al, Fe, Zn, Sb, or Mn is preferable. . The noble gas acts as a starting gas and a buffer gas. As the rare gas, xenon, argon, krypton, neon, or the like can be used alone or in combination of two or more. In the present invention, the term "high-pressure discharge" refers to a discharge in which the pressure during lighting of the ionization medium is equal to or higher than the atmospheric pressure, and is a concept including so-called ultra-high-pressure discharge.
[0028]
1. Light-emitting metal halide + mercury + rare gas: This is a configuration of a so-called metal halide lamp.
[0029]
2. Halide of luminescent metal + halide as lamp voltage forming medium + rare gas: This is a so-called mercury-free metal halide lamp which does not use mercury which has a large environmental load.
[0030]
3. Mercury + rare gas: This is a configuration of a so-called high-pressure mercury lamp.
[0031]
4. Rare gas: When Xe is used as the rare gas, a so-called xenon lamp is formed.
[0032]
Next, as the halide of the luminescent metal, one or more of iodine, bromine, chlorine, and fluorine can be used as the halogen. The metal halide of the luminescent metal is used to obtain the emission of visible light having desired emission characteristics such as emission color, average color rendering index Ra and emission efficiency. Accordingly, any desired one can be selected from known metal halides. For example, one or more halides selected from the group consisting of sodium Na, scandium Sc, rare earth metal and lithium Li can be used.
[0033]
<About Equation 1> Equation 1 (G / L _M <0.85) is an important component for ensuring glow-arc transition in the present invention, and G / L _M Is 0.85 or more, undesired glow discharge, that is, abnormal discharge is likely to occur between the metal pipes or between one metal pipe and the other electrode main part at the time of starting. When such abnormal discharge occurs, the electron emission becomes insufficient, so that transition to arc discharge becomes impossible. As a result, the probability of glow-arc transition at the time of starting decreases, and in many cases, transition from glow discharge to arc discharge cannot be performed. Ideally, the probability of glow-arc transition at start-up is always 100% throughout the life, but in practice it can be said that it is sufficient if it is 90% or more. G / L _M Is preferably 0.80 or less, since the probability of glow-arc transition is further increased. _M Is 0.75 or less, the probability of glow-arc transition is further increased, which is more preferable.
[0034]
<Other Configurations> In the present invention, although not an essential component, the performance of the high-pressure discharge lamp can be improved or new functions can be added by adding some or all of the following components as suitable components as desired. And can be added.
1. Overall length of high-pressure discharge lamp The overall length of the high-pressure discharge lamp is determined by the length of the translucent ceramic discharge vessel and the base ends of a pair of metal pipes protruding outward from both ends, and can generally be set freely. it can.
2. Lamp power Lamp power is the power that is recommended to be put into a high-pressure discharge lamp, and can be generally set freely. However, in the case of an automobile headlight, it is 20 to 50, preferably 30 to 30. ４０40, and 20 to 300, preferably 50 to 150 for the projector device.
3. Tube wall load The tube wall load of the high pressure discharge lamp is the unit surface area (cm) of the translucent ceramic exposed on the inner surface of the translucent ceramic discharge vessel. ² 20) / 100 W / cm for vehicle headlights ² , Preferably 25-80 W / cm ² It is.
4. Outer tube The outer tube is a light-transmitting container that houses therein a high-pressure discharge lamp whose outer shape is defined by a light-transmitting ceramic discharge container and a pair of metal pipes. In some cases, the whole may be called a high-pressure discharge lamp. The high-pressure discharge lamp of the present invention can be configured to be turned on when the translucent ceramics discharge vessel is exposed to the atmosphere. However, a translucent ceramics discharge vessel can be hermetically housed in the outer tube if desired, for example, as in a high pressure discharge lamp for a vehicle headlight. The reason for adding the outer tube can be based on the respective needs. For example, in the case of an automobile headlight, an outer tube structure adapted to block ultraviolet rays can be employed.
[0035]
The inside of the outer tube may be hermetically sealed or communicated with the outside air. When the inside of the outer tube is hermetically sealed, the inside can be evacuated or an inert gas can be sealed at an appropriate pressure.
5. Reflector When the reflector is added integrally, the high-pressure discharge lamp of the present invention can make the overall length relatively small with respect to the maximum diameter of the translucent ceramic discharge vessel. It becomes possible.
6. Starting auxiliary conductor The starting auxiliary conductor is formed by extending a conductor having a potential equal to the potential of one electrode to a position relatively close to the other electrode of the transparent ceramics discharge vessel, thereby lowering the starting voltage. Can be done.
[0036]
Generally, when the inner diameter of the surrounding portion of the translucent ceramic discharge vessel is relatively large and the distance between the electrodes is relatively large correspondingly, the starting voltage of the high pressure discharge lamp tends to increase. A starting auxiliary conductor can be provided as needed.
[0037]
<Regarding the operation of the present invention> In the present invention, by providing the above-described configuration, between the metal pipes exposed inside the translucent ceramic discharge vessel or between one metal pipe and the other electrode. Glow discharge hardly occurs. As a result, glow-arc transition at startup is facilitated.
[0038]
In addition, the high-pressure discharge lamp of the present invention has a relatively short overall length and can be miniaturized, so that it is suitable for condensing, especially for automobile headlights and projector devices.
[0039]
The above operation and effect do not change regardless of the lighting method of the high-pressure discharge lamp, for example, whether the lighting frequency is high frequency, for example, 45 kHz, or low frequency, for example, 50 to 500 Hz. In addition, the same holds true for either low-frequency AC lighting or DC lighting.
[0040]
A high-pressure discharge lamp according to a second aspect of the present invention includes a single-crystal translucent ceramic discharge vessel having a straight tubular shape with open ends, and a pair of air-tightly sealing both ends of the translucent ceramic discharge vessel. A base end supported by the sealing member, a tip protruding into the translucent ceramic discharge vessel, and a shortest distance L between the tip and the inner surface of the translucent ceramic discharge vessel. _B (Mm): a pair of electrodes satisfying Expression 2, and a discharge medium sealed in a translucent ceramics discharge vessel.
[0041]
(Equation 2)
0.4 ≦ L _B ≦ 3.0
The present invention specifies a preferable configuration of a high-pressure discharge lamp in which the size of a light source is reduced to the size of an arc.
[0042]
<Translucent Ceramics Discharge Vessel> In the present invention, the translucent ceramics discharge vessel may be of a single crystal type and a straight tube, and is generally not limited in material. For example, the single crystal translucent ceramic described in the first aspect of the invention can be used. The means for forming the translucent ceramic into a straight tube is not limited. For example, a single crystal that is pulled up into a straight tube and grown can be obtained by cutting into a suitable length, or a columnar or massive single crystal may be ground and formed into a straight tube. However, the former is superior in mass productivity.
[0043]
In addition, translucent ceramics having a linear transmittance of generally 80 to 90% can be obtained, but in the present invention, it is necessary that the transparent ceramic has a linear transmittance of at least 50% or more.
[0044]
Further, the dimensions of the translucent ceramics discharge vessel are not generally limited to a specific range, but preferably the numerical ranges for the automotive headlight and the projector device described in claim 1 are preferable. It is.
[0045]
<Regarding Sealing Member> The sealing member is a means for hermetically sealing both ends of the translucent ceramic. In the present invention, it is preferable to employ various known sealing structures.
1. Means for Inserting and Sealing a Metal Pipe This means is for inserting and sealing a metal pipe as defined in claim 1 into the opening at the end of the transparent ceramics discharge vessel. In this means, if the metal pipe is configured such that an external lead wire or the like is connected to a base end protruding outside the metal pipe, this can also function as an introduction conductor or a lamp supporting light body.
2. Means for Fitting and Sealing the Metal Pipe from Outside This means is a configuration in which the metal pipe is fitted and sealed outside the opening at the end of the translucent ceramics discharge vessel. In this means, the metal pipe is connected to the above 1 .. In the same manner as described above, it can function as an introduction conductor or a lamp support structure.
3. Means using ceramic closing member This means is to fit a disk-shaped closing member made of ceramic into the openings at both ends of the translucent ceramic discharge vessel, and seal the gap between them with appropriate means such as frit glass or shrink fitting. At the same time, the introduction conductor is sealed and supported on the closing member using frit glass, and the base end of the electrode shaft is connected to the inner front end of the introduction conductor.
[0046]
<About a pair of electrodes> A pair of electrodes can be comprised similarly to Claim 1. However, in the present invention, the shortest distance L formed between the tip of the electrode and the inner surface of the translucent ceramics discharge vessel. _B (Mm) is configured to satisfy Expression 2 described later.
[0047]
<Regarding Discharge Medium> The discharge medium can be configured in the same manner as in the first aspect.
[0048]
<About Equation 2> Equation 2 (0.4 ≦ L _B ≦ 3.0) defines the shortest distance between the electrode tip and the inner surface of the translucent ceramics discharge vessel in a single-crystal translucent ceramics discharge vessel having a straight tubular shape within a predetermined range. is there. That is, single-crystal translucent ceramics have high thermal conductivity and do not have crystal grain boundaries as in polycrystalline translucent ceramics. The gradient is small. In this regard, the thermal design of the translucent ceramics discharge vessel is relatively easy, but on the other hand, the heat capacity at the end is larger than that of a translucent ceramics discharge vessel similar to a sphere because of its straight tubular shape. Would. Therefore, the temperature gradient increases. In the high-pressure discharge lamp including the single-crystal translucent ceramic discharge vessel having a straight tubular shape, the distance between the arc and the electrode with respect to the change in the position of the surrounding portion surrounding the discharge space increases. In addition, it is difficult to carry out an appropriate thermal design so as not to cause inconveniences such as cracks due to thermal stress, but the present invention has made it possible to improve the thermal design. However, the shortest distance L _B If the lower limit is less than the lower limit of 0.4 mm, the temperature of the coldest part is high, so the luminous efficiency is high, but the inner surface temperature of the translucent ceramics discharge vessel is too high, and the translucent ceramics may melt and sublime. This is not possible because it is likely to cause blackening or white turbidity of the inner surface of the translucent ceramics discharge vessel to cause cracks or lower lamp characteristics. On the other hand, if the shortest distance exceeds the upper limit of 3.0 mm, the temperature of the coldest part is lowered and the luminous efficiency is too low, which is not possible.
[0049]
<Other Configurations in the Present Invention> Other configurations in the present invention are the same as in the first aspect of the present invention.
[0050]
<Regarding the Operation of the Present Invention> In the present invention, since the discharge vessel having a straight tubular shape is made of a single crystal-type translucent ceramic by having the above-described configuration, the translucent In addition to providing a high-efficiency, long-life high-pressure discharge lamp with a ceramic discharge vessel, the size of the arc is the size of the light source, so the size of the light source can be significantly reduced. As a result, the light collection efficiency is dramatically improved. Therefore, a highly effective high-pressure discharge lamp for a vehicle headlight or a projector can be obtained.
[0051]
In addition, since the discharge vessel is made of a single-crystal light-transmitting ceramic having a straight tubular shape, the structure is simple, so that the production becomes easy and a high-pressure discharge lamp can be obtained at relatively low cost. .
[0052]
Importantly, according to the high-pressure discharge lamp of the present invention, by satisfying the expression 2, cracks due to thermal stress and inconveniences such as melting and sublimation of the translucent ceramic are less likely to occur.
[0053]
A high pressure discharge lamp according to a third aspect of the present invention is the high pressure discharge lamp according to the second aspect, wherein the tube wall load P (W / cm ² ) Satisfies Equation 3.
[0054]
[Equation 3]
20 ≦ P ≦ 100
According to the present invention, in the high-pressure discharge lamp according to the second aspect of the present invention, a general range of a tube wall load suitable for an automobile headlight is specified. The tube wall load is calculated based on the following criteria. That is, the tube wall load is the unit surface area (cm) of the translucent ceramic exposed on the inner surface of the surrounding portion surrounding the discharge space of the translucent ceramic discharge vessel. ² ) Per lamp power (W). Tube wall load is generally 20-100 W / cm ² It is. However, the tube wall load is 25-80 W / cm ² In this case, the inner surface temperature of the translucent ceramic becomes more appropriate, and a long-life high-pressure discharge lamp can be obtained.
[0055]
Thus, in the present invention, since the tube wall load is within the predetermined range, the luminous efficiency and the color rendering properties are within appropriate ranges, and inconveniences such as cracks caused by thermal stress are less likely to occur.
[0056]
A high pressure discharge lamp lighting device according to a fourth aspect of the present invention includes the high pressure discharge lamp according to any one of the first to third aspects, and a lighting circuit for starting and energizing the high pressure discharge lamp. It is characterized by:
[0057]
In the present invention, as a lighting circuit of the high-pressure discharge lamp, various known circuit systems can be adopted. For example, a high-frequency lighting circuit, a low-frequency AC lighting circuit, a DC lighting circuit, or the like can be used. Note that it is permissible to use an igniter that generates a pulse voltage having a peak value of 15 kVp-p or more at the time of starting and applies the pulse voltage to the high-pressure discharge lamp.
[0058]
The high-frequency lighting circuit is a circuit system mainly including an inverter and an inductor suitable for lighting a fluorescent lamp incorporated in a bulb-type fluorescent lamp at a high frequency, and has a lighting frequency of more than 20 kHz to about 200 kHz or less. It is practical and suitable. According to such a high-frequency lighting circuit, the lighting circuit can be significantly reduced in size and weight, so that it is suitable for a high-pressure discharge lamp for general lighting.
[0059]
The low-frequency AC lighting circuit is a circuit system for lighting by applying a rectangular-wave AC voltage obtained by chopping a DC voltage at a low frequency using a full-bridge inverter or the like, and the lighting frequency is generally about 500 Hz or less. . In addition, the low-frequency AC lighting circuit is easy to control, for example, by inputting a lamp power of about 3.5 times the rated lamp power at the time of starting and shortening the luminous flux rising time. Is suitable for lighting.
[0060]
The DC lighting circuit is a circuit system for lighting by applying a DC output controlled by a chopper. Although it is preferable to use a high-pressure discharge lamp having an electrode structure for direct-current lighting for the DC lighting circuit, it is easy to control the high-pressure discharge lamp, and the lighting circuit can be reduced in size and weight. It is suitable for lamps, projector devices and general lighting.
[0061]
If necessary, an AC / DC switching type lighting circuit may be employed in which DC lighting is performed at the time of starting or for a certain period immediately after starting and at the time immediately after starting, and then switching to low-frequency AC lighting is performed.
[0062]
By the way, in order to instantaneously relight a high-pressure discharge lamp used for an automobile headlight or the like, a starting voltage having a peak value of 15 kVp-p (potential difference between positive and negative peak voltage values) is applied. However, a high-pressure discharge lamp provided with a translucent ceramics discharge vessel has a problem that it is susceptible to thermal shock at the time of starting and is easily cracked. However, although it is possible to overcome this, the restrictions such as dimensions are large, the design margin is small, and the use is limited. On the other hand, the high-pressure discharge lamp used in the present invention has good heat conduction between the electrode, the disk-shaped closing member made of metal pipe or ceramics, and the translucent ceramics discharge vessel, and it is difficult to form a temperature difference. The temperature distribution inside becomes relatively uniform. Thereby, resistance to thermal and electric shocks such as starting and blinking of the high pressure discharge lamp is high. Therefore, even if the high voltage pulse voltage at the start is generated by an igniter or the like and applied to the high pressure discharge lamp, the peak value of the high voltage pulse voltage is 15 kVp-p or more. Is less susceptible to damage. For this reason, it is possible to obtain a high-pressure discharge lamp lighting device that requires an instantaneous restart, such as a vehicle headlight.
[0063]
Further, when the translucent ceramics discharge vessel uses the high-pressure discharge lamp according to the second aspect of the present invention, since the single-crystal translucent ceramics is used, even if the translucent ceramics discharge vessel is in the form of a straight tube, it can be used in a polycrystalline form. Since the temperature distribution is better and the thermal gradient is smaller, even if the lamp is turned on by a lighting circuit having a peak voltage of a high voltage pulse voltage of 15 kVp-p or more at the start, a high-pressure discharge is caused by thermal and electrical shocks. Since the lamp is less susceptible to damage, it is ideal for high pressure discharge lamp lighting devices that require instantaneous restart, such as for automotive headlamps.
[0064]
A lighting device according to a fifth aspect of the present invention includes: a lighting device main body; a high-pressure discharge lamp according to any one of claims 1 to 3 supported by the lighting device main body; and starting and energizing the high-pressure discharge lamp. And a lighting circuit.
[0065]
In the present invention, the “illumination device” is a broad concept including any device that uses light emission of a high-pressure discharge lamp for some purpose. For example, the present invention is applied to a device that collects and uses light emitted from a high-pressure discharge lamp such as a vehicle headlight, a projector device, and a spotlight, various lighting fixtures, a bulb-type high-pressure discharge lamp, a light source device for optical fiber, and a photochemical device. Can be. The “illumination device main body” refers to the remaining portion excluding the high-pressure discharge lamp and the lighting circuit from the illumination device.
The "bulb-shaped high-pressure discharge lamp" is a type of incandescent lamp that integrates a high-pressure discharge lamp and its lighting circuit, further has a power receiving base, and is mounted in a lamp socket that is compatible with the base. Means a lighting device configured to be used as if it were turned on. In the case of configuring a bulb-type high-pressure discharge lamp, a reflector for condensing light emitted from the high-pressure discharge lamp so as to obtain desired light distribution characteristics can be provided. In addition, light-diffusing gloves or covers can be provided to reduce the high brightness of the high-pressure discharge lamp. Furthermore, a die having a desired specification can be used. Therefore, for the purpose of replacing the conventional light source lamp, the same base as that of the conventional light source lamp may be used.
[0066]
Further, when the lighting device is a lighting device, the lighting device may have a configuration in which a lighting circuit is provided with a high-pressure discharge lamp, or a configuration in which the lighting device is not provided with a bulb-type high-pressure discharge lamp. There may be. In the case of a lighting device provided with a lighting circuit, the lighting circuit may be provided in the lighting device, or may be provided at a position separated from the lighting device, for example, behind a ceiling.
[0067]
The lighting circuit may be configured to light the high-pressure discharge lamp with either high-frequency or low-frequency AC or DC. In addition, an instantaneous relighting function may not be provided.
[0068]
Embodiments of the present invention will be described below with reference to the drawings.
[0069]
FIG. 1 is a central sectional front view showing a first embodiment of the high-pressure discharge lamp of the present invention. In the figure, a high-pressure discharge lamp HPDL includes a translucent ceramics discharge vessel 1, a metal pipe 2, a pair of electrodes 3, 3, a fusion metal 4, and a discharge medium (not shown).
[0070]
The translucent ceramics discharge vessel 1 is made of translucent ceramics in the form of a straight tube, and has a central portion functioning as an enclosing portion 1a and both end portions functioning as sealing portions 1b and 1b. However, the surrounding portion 1a and the pair of sealing portions 1b and 1b have a cylindrical shape with the same diameter because the transparent ceramics discharge vessel 1 has a straight tubular shape. The translucent ceramics discharge vessel 1 is obtained by cutting a long transparent cylindrical material formed by a pulling growth method of pulling up a cylindrical shape into a required length.
[0071]
Both ends of the metal pipe 2 are open, and the distal end 2a is inserted into the sealing portion 1b to communicate with the inside of the translucent ceramic discharge vessel 1, and a small-diameter cylindrical portion is formed by a joining layer (not shown). The end of the translucent ceramics discharge vessel 1 is closed by being sealed to the inner surface of the end of 1b. In addition, the metal pipe 2 has its proximal end 2 b sealed with a fusion metal 4 to be described later, and is exposed outside the translucent discharge vessel 1.
[0072]
The joining layer that joins the inner surface of the translucent ceramics discharge vessel 1 and the outer surface of the metal pipe 2 is mainly composed of cermet, and the outer surface of the metal pipe 2 to be joined and the translucent ceramics discharge vessel 1 And an inner surface portion of the sealing portion 1b, and hermetically seals the both.
[0073]
Each of the pair of electrodes 3 has an electrode shaft 3a and an electrode main portion 3b. However, the electrode shaft is formed of one tungsten rod, the vicinity of the tip portion becomes the electrode main portion 3b, and the remaining portion becomes the electrode shaft 3a. The pair of electrodes 3, 3 have their base ends connected to the metal pipe 2 via a fusion metal 4, which will be described later, and the metal pipe 2 has a middle part of the electrode shaft 3 a separated from the inner surface of the metal pipe 2. The electrode main portion 3b projects into the surrounding portion 1a of the translucent ceramics discharge vessel 1.
[0074]
The fusion metal 4 seals an open end protruding outside the metal pipe 2 by being fused to a base end side of the metal pipe 2. The pair of electrodes 3, 3 are supported at predetermined positions by burying the base ends thereof in the fusion metal 4.
[0075]
One method of sealing the metal pipe 2 and supporting the electrode 3 is as follows. That is, a fusion metal bead (not shown) in which the base end of the electrode shaft 3a of the electrode 3 is embedded and connected in the fusion metal is prepared in advance. Next, the translucent ceramics discharge vessel 1 in which the metal pipe 2 is sealed is set vertically so that the opening on the base end side protruding outside the metal pipe 2 faces upward. Then, the electrode 3 is inserted from the outer opening end of the metal pipe 2, the fusion metal bead is positioned at the opening end of the metal pipe 2, and the fusion metal bead is irradiated with the YAG laser beam for a short time. As a result, the periphery of the fusion metal bead is melted, and a part of the metal bead enters the inside from the open end of the metal pipe 2, and as shown in the left half section of FIG. Since the metal pipe 2 is wetted and fused to the base end of the metal pipe 3a, the base end of the metal pipe 2 is sealed. At the same time, the electrode 3 extends along the central axis of the metal pipe 2 and is supported at a predetermined position.
[0076]
The discharge medium is composed of a luminous metal vapor, a lamp voltage forming medium, and a rare gas, and is sealed in the translucent ceramic discharge vessel 1. When the luminescent metal vapor is mercury vapor, it also serves as a lamp voltage forming medium, but when it is another metal vapor, it is sealed as a metal halide. As the lamp voltage forming medium, mercury or a halide having a relatively high vapor pressure is mainly used. The rare gas is used as a starting gas or a light flux forming medium at the beginning of lighting.
【Example】
Translucent ceramics discharge vessel 1: Made of colorless and transparent synthetic sapphire, diameter 3.1 mm, inner diameter 1.1 mm, length 12 mm
Metal pipe 2: made of molybdenum, outer diameter 1 mm, wall thickness 0.15 mm, overall length 5 mm, base side protruding length 3 mm, insertion length 2 mm, distance between metal pipes 8 mm
Bonding layer: mainly composed of a cermet obtained by sintering molybdenum powder and alumina ceramic powder, is formed porous, and the pores of the cermet are impregnated with frit glass.
[0077]
A pair of electrodes 3, 3: all made of tungsten, outer diameter 0.2mm, total length 8mm, distance between electrodes 2.2mm
Fusion metal 4: Molybdenum (Mo)
Discharge medium: mercury 0.3 mg, rare gas = argon (Ar) about 26.7 Pa
Lamp size: Total length 19mm
As a result of lighting the high-pressure discharge lamp of the above-described embodiment at a lamp power of 20 W using a lighting circuit in which an electronic circuit was formed, the glow-arc transition quickly occurred after starting, and the lighting was satisfactory. The tube wall load at this time was 68 W / cm. ² Met.
[0078]
FIG. 2 shows a high-pressure discharge lamp according to a first embodiment of the present invention in the same form as that of the first embodiment, in which the distance G between the electrodes is constant and the distance L between the metal pipes is constant. _M 7 is a graph showing the results obtained by manufacturing a high-pressure discharge lamp with various modifications of and measuring the starting probability. In the figure, the horizontal axis is G / L _M , And the vertical axis indicates the starting probability (%). Note that the “starting probability” means the probability that a glow-arc transition is performed at the time of starting and the lamp is turned on.
[0079]
As can be seen from the figure, G / L _M Is 0.85 or less, the starting probability becomes 90% or more. G / L _M Is 0.8 or less, the starting probability becomes 95% or more.
[0080]
FIG. 3 is a view similar to the example of the first embodiment of the high pressure discharge lamp of the present invention, and the shortest distance between the electrode tip and the inner surface of the transparent ceramic discharge vessel with the electrode eccentric from the central axis. 3 is a graph showing the results of producing various high-pressure discharge lamps and measuring the temperature of the outer surface of the translucent ceramic discharge vessel at the shortest distance. In the figure, the horizontal axis shows the electrode tip-discharge vessel shortest distance (mm), the vertical axis shows the shortest distance outer surface temperature (° C.) of the discharge vessel, and the right side shows luminous efficiency (lm / W). Curve A shows the outermost surface temperature of the discharge vessel at the shortest distance, and curve B shows the luminous efficiency.
[0081]
As can be understood from the figure, when the shortest distance between the electrode tip and the discharge vessel is less than 0.4 mm, the luminous efficiency is high, but the outermost surface temperature of the shortest distance of the discharge vessel exceeds 1000 ° C. The inner surface temperature of the shortest distance portion of the translucent ceramics discharge vessel exceeds 1200 ° C. assuming that the inner and outer surface temperature difference is 200 ° C. When the temperature exceeds 1200 ° C., sublimation of the translucent ceramic occurs.
[0082]
When the shortest distance between the electrode tip and the discharge vessel exceeds 0.8 mm, the coldest part temperature of the high-pressure discharge lamp becomes too low, and the luminous efficiency becomes lower than 80 lm / W.
[0083]
FIG. 4 is a front view showing a high-pressure discharge lamp according to a second embodiment of the present invention. In this embodiment, a required configuration is added so that a high-pressure discharge lamp similar to that shown in FIG. 1 is further mounted on a vehicle headlight device. In the figure, the high-pressure discharge lamp HPDL includes an arc tube IB, an outer tube OB, a base B, a pair of external leads OLa and OLb, and an insulating tube IT.
[0084]
The arc tube IB has the same structure as the high-pressure discharge lamp HPDL shown in FIG. 1, and the same parts as those in FIG. 1 are denoted by the same reference numerals.
[0085]
The outer tube OB has a pair of closed portions 5a and 5b formed by glass molding at both ends of a cylindrical hard glass, and houses the arc tube IB at a predetermined position therein. The closing portion 5a has a small axial length. On the other hand, the closing portion 5b is formed to be long in the axial direction, extends to the inside of the base 6 described later, and contributes to supporting the outer tube 5 on the base B. Note that the outer tube OB has an ultraviolet ray cutting performance.
[0086]
The base B has a structure standardized for a headlight of an automobile, and is configured to be mounted on the back of a headlight (not shown).
[0087]
The pair of external leads OLa, OLb both extend from the fusion metal 4 of the arc tube IB in the axial direction of the arc tube IB, and penetrate through the closing portions 5a, 5b of the outer tube OB to the outside of the outer tube OB. Derived. One of the external leads OLa is folded in an inverted U shape, extends parallel to the outer tube OB, enters the base B, and is connected to one base-shaped base terminal t1 of the base B. The other external lead OLb is connected to the other base terminal t2 (not shown) in the base B.
[0088]
The insulating tube IT covers one external lead OLa.
[0089]
FIG. 5 is a circuit diagram showing one embodiment of the high pressure discharge lamp lighting device of the present invention. This embodiment is suitable for a headlight of an automobile, and is configured to AC-light a high-pressure discharge lamp as shown in FIG. In the figure, a high-pressure discharge lamp lighting device includes a DC power supply DC, a step-up chopper BT, a full-bridge inverter FBI, an igniter IG, a high-pressure discharge lamp HPDL, and control means CC.
[0090]
The DC power supply DC is means for supplying a DC power supply voltage to a boost chopper BT described later, and a battery or a rectified DC power supply is used. In the case of a high pressure discharge lamp lighting device for a vehicle headlight, a battery is generally used. However, a rectified DC power supply that rectifies AC may be used. If necessary, an electrolytic capacitor C1 is connected in parallel to perform smoothing.
[0091]
The step-up chopper BT is well known in this field as a DC-DC conversion circuit that converts a DC voltage into a DC voltage having a higher required value, and is supplied to a high-pressure discharge lamp HPDL via a full-bridge inverter FBI described later. The desired lamp power can be controlled by adjusting the output voltage. If the DC power supply voltage is too high, a step-down chopper can be used.
[0092]
The full-bridge inverter FBI includes a bridge circuit BC composed of four MOSFETs Q1, Q2, Q3 and Q4, MOSFETs Q1 and Q3 of the bridge circuit BC, a gate drive circuit GDC for alternately switching between Q2 and Q4, and a polarity inversion circuit INV. The DC voltage from the step-up chopper BT is converted into a rectangular wave low-frequency AC voltage by the above-described switching, and applied to the high-pressure discharge lamp HPDL to perform low-frequency AC lighting.
[0093]
The igniter IG is operated by the output of the full-bridge inverter FBI to generate a high-voltage pulse voltage and apply it between the electrodes of the high-pressure discharge lamp HPDL.
[0094]
The high-pressure discharge lamp HPDL having the same configuration as that shown in FIG. 4 is connected to the output terminal of the full-bridge inverter FBI.
[0095]
The control means CC includes a program control means PC, a lamp current detection means IDC, and a lamp voltage detection means VDC. The program control means PC incorporates a predetermined lamp power control program in advance, and controls the boost chopper BT according to the program. The current detecting means IDC detects a lamp current flowing through the high-pressure discharge lamp, and performs control input to the gate drive circuit GDC and the program control means PC. The lamp voltage detecting means VDC detects the lamp voltage of the high-pressure discharge lamp and performs control input to the gate drive circuit GDC and the program control means PC. At least until the rated lamp power is reached immediately after starting, the program control means PC compares the control program with the actual lamp power obtained by calculation based on the detected data to determine the difference. Then, the program control means PC controls the gate drive circuit GDC according to the difference, and automatically controls the lamp power supplied to the high-pressure discharge lamp according to a predetermined program.
Immediately after the boost chopper BT is turned on, about 3.5 times the rated lamp power is supplied to the high-pressure discharge lamp HPDL via the full-bridge inverter FBI, and then gradually reduced to reduce the rated lamp power. The boost chopper BT is controlled so as to settle down to electric power. In addition, it controls the gate drive circuit GDC of the full-bridge inverter FBI as required.
[0096]
Then, when the high-pressure discharge lamp is lit with the low-frequency alternating current of the rectangular wave using the high-pressure discharge lamp lighting device according to the present embodiment, a required luminous flux is generated immediately after lighting. As a result, it is possible to achieve lighting of 25% of the luminous flux with respect to the rating one second after the power is turned on, which is necessary for a vehicle headlamp, and 80% of the luminous flux after 4 seconds.
[0097]
FIG. 6 is a perspective view showing one embodiment of the automotive headlight device of the present invention, as viewed from the rear. In the figure, in the figure, the vehicle headlight device (HL) includes a vehicle headlight device main body (21), and a pair of lighting circuits (OC) and a metal halide lamp (MHL ′), respectively.
[0098]
The vehicle headlamp apparatus main body (21) includes a front transmission panel (21a), reflectors (21b) and (21c), a lamp socket (21d), a mounting part (21e), and the like.
[0099]
The front transmissive panel (21a) has a shape conforming to the outer surface of the automobile and includes necessary optical means such as a prism.
[0100]
The reflectors (21b) and (21c) are provided corresponding to the metal halide lamp (MHL '), and are configured to obtain the light distribution characteristics required for each.
[0101]
The lamp socket (21d) is connected to the output terminal of the lighting circuit (OC) and is mounted on the base (21d) of the metal halide lamp (MHL ').
[0102]
The mounting portion (21e) is a means for mounting the vehicle headlamp device main body (21) at a predetermined position of the vehicle.
[0103]
The metal halide lamp (MHL ') has a structure according to the embodiment of the invention of claim 5 shown in FIG. The lamp socket (21d) is attached to a base and connected.
[0104]
Then, the two metal halide lamps (MHL ') are mounted on the vehicle headlamp apparatus main body (21) to constitute a four-lamp type vehicle headlamp apparatus (HL). The light emitting portion of the metal halide lamp (MHL ') is located substantially at the focal point of the reflectors (21b) and (21c) of the vehicle headlamp apparatus body (21).
[0105]
The lighting circuit (OC) has a circuit configuration shown in FIG. 21 and is housed in a metal container (22) and energizes and lights a metal halide lamp (MHL ').
[0106]
【The invention's effect】
According to the first aspect of the present invention, the transparent ceramic discharge vessel and the opening at the tip end are inserted into the end of the transparent ceramic discharge vessel and sealed, thereby closing both ends thereof, and , The distance between the tips L _M And a pair of metal pipes whose base ends are exposed and sealed to the outside of the translucent ceramics discharge vessel, and whose base ends are connected to and supported by the base-side sealing portion of the metal pipe, A discharge medium including a pair of electrodes whose tips protrude into the translucent ceramic discharge vessel at a distance of G and a discharge medium, and the distance ratio G / L _M Satisfies Expression 1, it is possible to provide a high-pressure discharge lamp in which abnormal discharge is unlikely to occur and glow-arc transition at the start is easy.
[0107]
According to the invention of claim 2, a single-crystal translucent ceramic discharge vessel having a straight tubular shape, and a pair of sealing members that hermetically seal both ends of the translucent ceramic discharge vessel, The base end is supported by the sealing member, the tip protrudes into the translucent ceramics discharge vessel, and the shortest distance L between the tip and the inner surface of the translucent ceramics discharge vessel. _B By providing a pair of electrodes whose (mm) satisfies Expression 2 and a discharge medium, the size of the light source is reduced, the light collecting property is high, the structure is simple, and the manufacturing is simple. It is possible to provide a high-pressure discharge lamp that is easy and hardly causes cracks due to thermal stress.
[0108]
According to the invention of claim 3, the tube wall load P (W / cm ² By satisfying Expression 3, it is possible to provide a high-pressure discharge lamp in which luminous efficiency and color rendering properties fall within appropriate ranges, and in which inconveniences such as cracks due to thermal stress do not easily occur.
[0109]
According to a fourth aspect of the present invention, a high pressure discharge lamp according to any one of the first to third aspects and a lighting circuit for starting and energizing the high pressure discharge lamp are provided. A high pressure discharge lamp lighting device having the effects of 1 to 3 can be provided.
[0110]
According to the invention of claim 5, the lighting device main body, the high-pressure discharge lamp according to any one of claims 1 to 3 supported by the lighting device main body, and lighting for starting and energizing the high-pressure discharge lamp With the provision of the circuit, a lighting device having the effects of claims 1 to 3 can be provided.
[Brief description of the drawings]
FIG. 1 is a central sectional front view showing a first embodiment of a high-pressure discharge lamp of the present invention.
FIG. 2 shows a high-pressure discharge lamp according to a first embodiment of the present invention in the same form as that of the first embodiment, with a constant distance G between electrodes and a distance L between metal pipes. _M Is a graph showing the results of measuring the starting probabilities of high pressure discharge lamps with various modifications
FIG. 3 is a view similar to the embodiment of the first embodiment of the high-pressure discharge lamp of the present invention, and the shortest distance between the tip of the electrode and the inner surface of the translucent ceramic discharge vessel with the electrode eccentric from the central axis. Is a graph showing the results of measuring the temperature of the outer surface of a translucent ceramic discharge vessel at the shortest distance site by manufacturing various high-pressure discharge lamps
FIG. 4 is a front view showing a high-pressure discharge lamp according to a second embodiment of the present invention.
FIG. 5 is a circuit diagram showing one embodiment of the high pressure discharge lamp lighting device of the present invention.
FIG. 6 is a perspective view showing one embodiment of the automotive headlight device of the present invention, viewed from the back.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Translucent ceramics discharge container, 1a ... Surrounding part, 1b ... Small-diameter cylindrical part, 2 ... Metal pipe, 2a ... Tip side, 2b ... Base end side, 3 ... Electrode, 3a ... Electrode shaft, 3b ... Electrode main part 4, fusion metal

Claims (5)

A translucent ceramic discharge vessel open at both ends;
By opening portion of the tip side is sealed by inserting the end portion of the light-transmissive ceramic discharge vessel closed at both ends of the translucent ceramic discharge vessel, and opposed at a distance L _M between the tips, A pair of metal pipes whose base ends are exposed to the outside of the translucent ceramic discharge vessel and are sealed;
A pair of electrodes having a base end connected to and supported by a base-side sealing portion of the metal pipe, and having a front end protruding into the translucent ceramic discharge vessel at a distance of G with a distance G;
A discharge medium enclosed in a translucent ceramic discharge vessel;
Comprising a high-pressure discharge lamp the ratio of the distance G / L _M is characterized in that it satisfies the equation 1.

A single-crystal translucent ceramic discharge vessel having a tubular shape with both ends open;
A pair of sealing members that hermetically seal both ends of the translucent ceramic discharge vessel;
The base end is supported by the sealing member, the tip protrudes into the translucent ceramic discharge vessel, and the shortest distance L _B (mm) between the tip and the inner surface of the translucent ceramic discharge vessel satisfies Equation 2. A pair of electrodes;
A discharge medium enclosed in a translucent ceramic discharge vessel;
A high pressure discharge lamp comprising:

High-pressure discharge lamp according to claim 2, wherein the bulb wall loading P to (W / cm ²⁾ is characterized by satisfying Equation 3.

A high-pressure discharge lamp according to any one of claims 1 to 3, and
A lighting circuit for starting and energizing the high-pressure discharge lamp;
A high pressure discharge lamp lighting device, comprising: A lighting device body;
4. The high-pressure discharge lamp according to claim 1, which is supported by a lighting device body;
A lighting circuit for starting and energizing the high-pressure discharge lamp;
A lighting device, comprising:

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