JP2008177160A - High pressure discharge lamp and lighting device - Google Patents

Abstract

【Task】
Providing high-pressure discharge lamps with practical electrical and luminescent properties without substantial encapsulation of mercury and mercury substitute materials, ie, lamp voltage forming halides, with minimal color deviation and improved lifetime characteristics To do.
[Solution]
The high-pressure discharge lamp includes a light-transmitting hermetic container 1 having a discharge space 1c therein, a pair of electrodes 2 and 2 facing the discharge space, a metal halide and a rare gas, and the metal halide is sealed in all. An ionization medium containing at least one halide of thulium (Tm) and holmium (Ho) with an encapsulation ratio of 30% by mass or more with respect to a metal halide, wherein the rare gas is xenon (Xe) at 3 ° C. or more at 25 ° C. The metal halide for forming the lamp voltage and mercury are substantially not contained in the light-transmitting hermetic container.
[Selection] Figure 1

Description

  The present invention relates to a high-pressure discharge lamp essentially free of mercury and a lighting device including the same.

A high-pressure discharge lamp in which the amount of enclosed ZnI ₂ as a mercury substitute material is regulated is known (for example, see Patent Document 1).

  Further, the main light emitting metal is a metal selected from the group of Na, Tl and Dy as a main component, and one or more of Ho, Tm and In are encapsulated as subcomponents, and Al, Zn and A high-pressure discharge lamp using a halide such as Fe is known (see Patent Document 2).

JP 2003-303571 A Japanese Patent Laid-Open No. 2004-055140

A known mercury-free high-pressure discharge lamp (hereinafter referred to as “mercury-free lamp” for convenience) encloses a so-called second metal halide for forming a lamp voltage, such as ZnI ₂ , in addition to a light-emitting metal halide. Yes. A mercury-free lamp that does not enclose the second metal halide is also known, but a practical lamp voltage cannot be obtained or a special lighting mode is required, which is not practical.

However, there is a problem when a second metal halide for forming a lamp voltage such as ZnI ₂ is encapsulated. That is, the hygroscopic property is remarkable and becomes a main factor for introducing moisture into the lamp as an impurity. Therefore, the lamp life is improved as the second metal halide such as ZnI ₂ is reduced.

Moreover, there is also a problem that as the amount of the second halide such as ZnI ₂ increases, white turbidity due to the reaction between these halides and the light-transmitting hermetic container tends to become more prominent. For this reason, the lamp life is improved by reducing the amount of so-called second halide such as ZnI ₂ .

Furthermore, since the _second halide such as ZnI ₂ has a lower melting point than that of a luminescent metal halide such as Tm, for example, there is a problem that it is not possible to produce a pellet in which these are mixed together. . For this reason, the pellet enclosed in a translucent airtight container will be 2 or more types, and a manufacturing cost will rise.

The present inventor encloses a so-called second halide such as ZnI ₂ and a thulium (Tm) or holmium (Ho) halide known as a luminescent metal without using mercury in a light-transmitting airtight container. It has been found that the color deviation decreases as the lamp voltage increases. The present invention has been made based on this discovery.

  The present invention is a high voltage with practical electrical and luminescent properties without substantial encapsulation of mercury and mercury substitute materials, ie, lamp voltage forming halides, with low color deviation and improved lifetime characteristics. It is an object of the present invention to provide a discharge lamp and an illumination device including the discharge lamp.

    The high-pressure discharge lamp of the present invention includes a translucent airtight container having a discharge space therein; discharge generating means for generating discharge in the discharge space of the translucent airtight container; and a metal halide and a rare gas, and The metal halide contains at least one halide of thulium (Tm) and holmium (Ho) having an encapsulation ratio of 30% by mass or more with respect to all the metal halides enclosed, and the rare gas is 3 atmospheres or more at 25 ° C. An ionization medium sealed in a light-tight airtight container of xenon (Xe), and containing substantially no metal halide and mercury for forming a lamp voltage in the light-tight airtight container It is characterized by.

  [Translucent airtight container] In the present invention, the translucent airtight container means an airtight container capable of deriving visible light in a desired wavelength region generated by discharge to the outside, and has translucency. It can be made of any material that is fire resistant enough to withstand the normal operating temperature of the lamp. For example, quartz glass or translucent ceramics can be used. However, a light-transmitting hermetic container made of light-transmitting ceramics is particularly suitable in the present invention because the coldest part temperature can be set high, the lamp voltage can be increased, and the luminous efficiency can be improved. . As the translucent ceramic, translucent alumina, yttrium-aluminum-garnet (YAG), yttrium oxide (YOX), and polycrystalline non-oxide such as aluminum nitride (AlN) or single crystal Crystal ceramics or the like can be used. If necessary, it is allowed to form a halogen-resistant or metal-resistant transparent coating on the inner surface of the hermetic container or to modify the inner surface of the translucent hermetic container.

  Moreover, the translucent airtight container has a discharge space inside. And in order to enclose discharge space, the translucent airtight container is provided with the enclosing part. The surrounding portion has an appropriate shape, for example, a spherical shape, an elliptical spherical shape, or a substantially cylindrical shape. Various values can be selected as the volume of the discharge space according to the rated lamp power of the metal halide lamp, the distance between the electrodes, and the like. For example, in the case of a liquid crystal projector lamp, it can be 1.0 cc or less. In the case of a vehicle headlamp, it can be 0.05 cc or less. In the case of a general illumination lamp, it can be set to 1 cc or more and any of the following depending on the rated lamp power.

  Further, it is allowed to have a pair of sealing portions at both ends of the surrounding portion. The pair of sealing portions are means for sealing the surrounding portion and supporting the shaft portion of the electrode here and contributing to airtight introduction of current from the lighting circuit to the electrode. It is arrange | positioned at the both ends of the part. When the material of the hermetic container is quartz glass, it is preferable to seal the metal as an appropriate hermetic sealing conduction means inside the sealing part in order to seal the electrode and introduce the current from the lighting circuit to the electrode in a hermetic manner. A structure in which a foil is embedded in an airtight manner can be employed. Note that the sealing metal foil is embedded in the inside of the sealing portion, and the sealing portion serves as a current conducting conductor in cooperation with the sealing portion in order to keep the inside of the enclosure portion of the translucent airtight container airtight. When the translucent airtight container is made of quartz glass, molybdenum (Mo) is the most suitable material. The method of embedding the sealing metal foil in the sealing portion is not particularly limited, but can be appropriately selected and employed from, for example, a reduced pressure sealing method, a pinch sealing method, and a combination thereof.

  On the other hand, as a sealing means when the light-transmitting hermetic container is made of a light-transmitting ceramic, for example, a frit glass is poured between the light-transmitting ceramic and the introduction conductor, and the frit sealing is replaced with a frit glass. Various sealing means such as metal sealing using metal and means for directly or indirectly sealing the current-introducing conductor by melting the opening to be sealed of the translucent ceramic hermetic container are selectively used as required. can do. In order to maintain the lowest temperature of the discharge space formed in the light-transmitting hermetic container at a desired relatively high temperature while maintaining the sealing portion of the light-transmitting hermetic container at a required relatively low temperature. In addition, a small-diameter cylindrical portion communicating with the surrounding portion can be formed. In the case of this structure, the sealing portion is disposed at the end portion of the small diameter cylindrical portion, and is called a capillary between the electrode shaft and the inner surface of the small diameter cylindrical portion by extending the electrode shaft in the small diameter cylindrical portion. A slight gap is formed along the axial direction of the small-diameter cylindrical portion.

  [Discharge Generation Unit] The discharge generation unit can be formed, for example, by a pair of electrodes that are sealed in a light-transmitting airtight container and disposed so as to face the discharge space. In the case of a liquid crystal projector or the like, the distance between electrodes formed in this case is preferably 2 mm or less, and may be 0.5 mm. For headlamps, a center value of 4.2 mm is standardized. In the case of a general illumination lamp, it can be set to 6 mm or less for a small lamp with a small distance between electrodes, and to 6 mm or more for a medium or large lamp.

  In addition, as a constituent material of the electrode, a fire-resistant and conductive metal such as pure tungsten (W), a dopant (for example, scandium (Sc), aluminum (Al), potassium (K), and silicon (Si), etc. It can be formed using doped tungsten containing one or more selected from the group, tritium tungsten containing thorium oxide, rhenium (Re), tungsten-rhenium (W-Re) alloy, or the like.

  Further, in the case of a small lamp, a straight rod-shaped wire or a wire having a large diameter portion at the tip can be used as the electrode. In the case of a medium or large electrode, a coil made of an electrode constituent material can be wound around the tip of the electrode shaft. Note that the pair of electrodes have the same structure when operated with alternating current, but when operated with direct current, the anode generally has a large temperature rise, so that the heat radiation area is larger than the cathode, and therefore the main part should be thick. Can do.

  In addition to the pair of electrodes sealed in the translucent airtight container, the discharge generating means is a so-called electrodeless type or dielectric barrier discharge that is provided outside the container and generates inductively coupled discharge. It may be an external electrode type discharge generating means for generating

  [Ionization Medium] The ionization medium is a characteristic component of the present invention, and contains a metal halide and a rare gas.

    (Regarding Metal Halide) The metal halide contains at least one halide of thulium (Tm) and holmium (Ho) in a predetermined ratio. The said predetermined ratio is 30 mass% or more with respect to all the halides enclosed in the translucent airtight container. Therefore, addition of halides of other metals up to 70% by mass is allowed. Note that when the enclosure ratio of at least one halide of thulium (Tm) and holmium (Ho) is less than 30% by mass, the increase in lamp voltage does not increase to a desired range.

  Further, it is preferable that the encapsulating ratio of at least one of thulium (Tm) and holmium (Ho) halides is 50% by mass or more because a higher lamp voltage can be obtained.

  As the halogen that forms at least one halide of thulium (Tm) and holmium (Ho), iodine is suitable because it has a moderate reactivity, but if desired, either bromine or chlorine can be used. In addition, two or more desired kinds of iodine, bromine and chlorine may be used. Furthermore, thulium is a light-emitting metal that is extremely effective in improving the light-emitting efficiency because its emission peak coincides with the peak of the visibility curve. Holmium also has similar properties to thulium.

  If the encapsulation ratio exceeds 80% by mass, the encapsulation ratio of halides of metals other than thulium (Tm) and holmium (Ho) is correspondingly reduced, and as a result, desired white light emission cannot be obtained. Therefore, it is not preferable for the purpose of obtaining white light emission.

  In addition to obtaining white light emission as described above, other metal halides may contain at least one of thulium (Tm) and holmium (Ho) for the purpose of, for example, adjusting the chromaticity of light emission or increasing the light emission efficiency. It can be added to the seed and encapsulated. Luminous efficiency becomes high when the said enclosure ratio is the range of 50-70 mass%.

  The other metal halides can be appropriately added for various purposes, and are not particularly limited in the present invention. Hereinafter, main examples of other metal halides will be described.

  1. (Alkali metal) If the alkali metal is 60% by mass, preferably 50% by mass with respect to all metal halides, the effect of reducing the lamp voltage can be obtained, and more preferably less than 30% by mass, When various conditions such as light emission characteristics and manufacturability are allowed, the lamp voltage drop is suppressed to a minimum by enclosing within a range of less than 3% by mass, while the light emission efficiency, lamp life improvement and light are reduced. Color adjustment, especially color deviation improvement, becomes possible. From such a point of view, encapsulation is allowed within a range in which a required lamp voltage can be secured. In addition, Preferably it is 2-8 mass%, More preferably, it is 3-7 mass%, More preferably, it is 4-6 mass%. Further, as other alkali metals, one or a plurality of groups of sodium (Na), cesium (Cs), and lithium (Li) can be selectively encapsulated.

  2. (Other Rare Earth Metal Halides) As a rare earth metal halide other than thulium (Tm) and holmium (Ho), one or more kinds of rare earth metals consisting of praseodymium (Pr), cerium (Ce) and samarium (Sm) Halides can be encapsulated as a minor component. The rare earth metal is useful as a luminescent metal next to thulium halide and holmium halide, and is allowed to be encapsulated at an encapsulation ratio of a predetermined amount or less. That is, any of the rare earth metals has an infinite number of bright line spectra in the vicinity of the peak wavelength of the visibility characteristic curve, and thus can contribute to an improvement in luminous efficiency.

  3. (Hallium of thallium (Tl) and / or indium (In)) Halide of thallium (Tl) and / or indium (In) is a minor component for the purpose of obtaining desired color rendering properties and / or color temperature. It is acceptable to selectively enclose as.

    (Rare Gas) As for the rare gas, xenon (Xe) is sealed at 3 atm or more in terms of room temperature (25 ° C.). The reason why the sealed pressure of xenon is increased as described above is that an increase in lamp voltage and an improvement in luminous efficiency can be obtained. That is, in the present invention, the increase in lamp voltage due to the encapsulation at least one of thulium (Tm) and holmium (Ho) in the above mixing ratio and the increase in lamp voltage due to the above encapsulation pressure of xenon coexist. A desired high lamp voltage can be obtained. However, when the sealed pressure of xenon is less than 3 atmospheres, the lamp voltage cannot be increased to a desired level. When the xenon sealing pressure is 5 atm or more, the effect of increasing the lamp voltage becomes more remarkable, which is preferable. However, if the pressure exceeds 15 atmospheres, the rate of increase in the lamp voltage is greatly reduced.

  On the other hand, the enclosed pressure of xenon and the luminous efficiency show a positive correlation, but if the pressure is less than 3 atm, the desired luminous efficiency cannot be obtained. On the other hand, when the pressure exceeds 15 atmospheres, the increase in luminous efficiency is slow.

  In summary, the enclosed pressure of xenon is preferably 15 atm or less.

[Regarding Metal Halide and Mercury for Forming Lamp Voltage] In the present invention, the metal halide and mercury for forming the lamp voltage are not substantially enclosed in the inside of the light-transmitting airtight container. In the prior art, as described above, a metal halide for forming a lamp voltage represented by ZnI ₂ as a medium for forming a lamp voltage has an ionization energy of 8 eV or more and a melting point of 500 ° C. or less. Often contains metal halides. Examples of metal halides having an ionization energy of 8 eV or more and a melting point of 500 ° C. or less include zinc (Zn), aluminum (Al), and manganese (Mn) halides.

  In the case of the present invention, a desired lamp voltage is formed by encapsulating at least one of thulium halide and holmium halide in a predetermined ratio and enclosing xenon at 3 atmospheres or more. Do not enclose. “Substantially not encapsulating” means that, for example, it is allowed when it is contained in an impurity level of 1% by mass or less of the entire encapsulated substance.

  The metal halide for forming the lamp voltage has a higher vapor pressure than the halide enclosed in the light-transmitting hermetic container in the present invention, and has an effect of mainly determining the lamp voltage in the high-pressure discharge lamp. Note that “the vapor pressure is high” means that the vapor pressure during lighting is high, but it is not necessary to be too high like mercury, and preferably the pressure in the airtight container during lighting is about 5 atm or less. is there. Therefore, it is not limited to a specific metal halide as long as the above conditions are satisfied.

The lamp voltage forming halide is mainly composed of a metal halide that forms a lamp voltage. For example, magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), zinc (Zn), From nickel (Ni), manganese (Mn), aluminum (Al), antimony (Sb), beryllium (Be), rhenium (Re), gallium (Ga), titanium (Ti), zirconium (Zr) and hafnium (Hf) One or a plurality of types of metal halides selected from the group can be used as a main component. Most of them have a vapor pressure lower than that of mercury, and the adjustment range of the lamp voltage is narrower than that of mercury. However, the adjustment range of the lamp voltage can be expanded by mixing and enclosing a plurality of these as required. For example, when AlI ₃ is in an incompletely evaporated state and a desired lamp voltage is not obtained, the lamp voltage does not change even if AlI ₃ is added.

On the other hand, if ZnI ₂ is added instead of adding AlI ₃ , the lamp voltage corresponding to the action of ZnI ₂ is added, so that the lamp voltage can be increased. Furthermore, if another halide for forming a lamp voltage is added, a higher lamp voltage can be obtained.

  Furthermore, the halide for forming the lamp voltage is a metal halide that does not easily emit light in the visible region as compared with the metal of the halide enclosed in the light-transmitting hermetic container. The phrase “difficult to emit light in the visible region compared to the metal of the halide” does not mean that light emission of visible light is small in an absolute sense, but a relative meaning. For sure, Fe and Ni emit more in the ultraviolet region than in the visible region, but Ti, Al, Zn and the like emit more in the visible region. Therefore, when these metals that emit a lot of light in the visible region are caused to emit light alone, energy is concentrated on the metal, so that there is a lot of light in the visible region. Among the lamp voltage forming halides, iron (Fe) and nickel (Ni) emit much in the ultraviolet region, but titanium (Ti), aluminum (Al), zinc (Zn), etc. emit light alone. Emits much light in the visible light range. However, the lamp voltage forming halides such as titanium (Ti), aluminum (Al), and zinc (Zn) described above mainly contribute to light emission such as thulium (Tm) as energy levels necessary for light emission. It is higher than the energy level required for causing the halide (halide for light emission) to emit light. For this reason, when the high pressure discharge lamp is turned on by enclosing both together, light emission by the light emitting halide having a low energy level becomes relatively dominant, and light emission by the lamp voltage forming halide is small.

  Therefore, the latter halide is not prohibited from emitting visible light, and has a small influence on the total visible light emitted by the discharge lamp and has little influence. However, it has been clarified through experiments by the present inventors that a high-pressure discharge lamp used in a mixed state in which both halides are mixed has disadvantages in lamp characteristics as described later.

  [Other Configurations] In the present invention, the following configurations can be selectively added as desired.

  1. (Outer tube) The light emitting tube can be disposed inside the outer tube by using a light-transmitting airtight container, a pair of electrodes and a discharge medium as a light emitting tube. The outer tube can be any desired shape and size. Further, the inside of the outer tube may be airtight with respect to the outside, and the coldest part temperature of the arc tube may be increased by keeping it in a vacuum or a reduced pressure state. When the arc tube material is quartz glass, You may make it communicate. When making it airtight with respect to external air, inert gas, such as argon and nitrogen, can be enclosed as needed. Furthermore, the outer tube can be formed using a translucent material such as quartz glass, hard glass, or soft glass.

  2. (Reflection mirror) A translucent airtight container can be fixedly disposed at a predetermined position in the reflection mirror. As the reflection mirror, a glass substrate in which an infrared transmission / visible light reflection type dichroic mirror is formed can be used.

  3. (Rated lamp power) In the present invention, the rated lamp power of the high-pressure discharge lamp can be freely set from a wide range of values, for example, can be set to an arbitrary value of several kW or less. It can be used in various ways and is suitable, for example, for automotive headlamps, projections, and general lighting. Accordingly, an airtight container having an appropriate shape and size, an appropriate distance between electrodes, and an appropriate amount of discharge medium can be provided depending on the rated lamp power and application.

  [Operation of the Present Invention] The operation of the present invention is as follows.

  1. A practical high lamp voltage can be obtained. In the present invention, when at least one of thulium and holmium in the ionization medium is sealed at a predetermined sealing ratio, the lamp voltage can be increased. Moreover, the lamp voltage is increased by enclosing xenon at a predetermined pressure. Thus, in the present invention, a desired lamp voltage can be obtained by the action of increasing both the lamp voltages.

Accordingly, in the present invention, the ionization energy such as ZnI ₂ as in the prior art is more than 8 eV, and even without melting point enclosing a halide or mercury lamp voltage formation consisting of 500 ° C. or less of the metal halide The required practical lamp voltage can be obtained.

  2. Practical light emission characteristics can be obtained. In the present invention, at least one halide of thulium and holmium is sealed at a predetermined sealing ratio, so that white light emission is emitted with high efficiency.

  Therefore, in the present invention, the required practical luminous efficiency can be obtained.

3. Color deviation is reduced. In the present invention, x in the chromaticity diagram is increased by enclosing at least one halide of thulium and holmium at a predetermined encapsulation ratio, and not encapsulating, for example, ZnI ₂ as a lamp voltage forming halide, and There is a tendency for y to decrease. As a result, the positive color deviation value is reduced, and the chromaticity is improved in the direction approaching the black body radiation line. On the other hand, for example, in the ScI ₃ -NaI system which is a known inclusion, if ZnI ₂ is not encapsulated, both x and y in the chromaticity diagram increase, and the positive color deviation value further increases. There is a problem.

4). Lamp life is improved.
(1) In the present invention, since the halide for forming the lamp voltage with high hygroscopicity is not enclosed, the moisture of impurities is not brought into the translucent airtight container. As a result, the lamp life is improved.
(2) By not encapsulating the halide for forming the lamp voltage, white turbidity caused by the reaction between the halide and the translucent airtight container is not generated. As a result, the lamp life is improved.

  5. An increase in manufacturing costs can be avoided. In the present invention, since the halide for forming the lamp voltage is not encapsulated, there is no problem described above in the pellet manufacturing. Therefore, an increase in manufacturing cost can be avoided.

  An illuminating device of the present invention comprises: an illuminating device main body; a high-pressure discharge lamp according to any one of claims 1 to 5 disposed in the illuminating device main body; and a lighting device that lights the high-pressure discharge lamp. It is characterized by having.

  In the present invention, the lighting device is a concept including a device using the high-pressure discharge lamp of the present invention as a light source, such as a lighting fixture, a marker lamp, an indicator lamp, a photochemical reaction device, and the like. In addition, the lighting device main body refers to all of the remainder excluding the high-pressure discharge lamp from the lighting device.

  The lighting device can be configured by a lighting circuit for energizing and lighting the high-pressure discharge lamp, and a high-voltage pulse generator for starting the lighting by starting the high-pressure discharge lamp. In the present invention, various known lighting circuits can be employed as the lighting circuit. For example, a circuit configuration such as a full-bridge inverter circuit or a half-bridge inverter circuit, preferably a rectangular wave AC generating circuit that generates a rectangular AC voltage having a low frequency can be used. In addition, a DC voltage conversion circuit such as a step-up chopper or a step-down chopper can be attached to the DC power source of the inverter circuit for power supply voltage adjustment and / or active filter, if desired. Various known high voltage pulse generators can be employed as the high voltage pulse generator. For example, an igniter can be used.

  Further, it is preferable to use a connection conductor connecting the high voltage pulse generator and the high pressure discharge lamp having a dielectric strength of 9 kV or more. Since the high-pressure discharge lamp of the present invention does not enclose mercury as a lamp voltage forming substance, the starting voltage tends to be relatively high. For this reason, a high-voltage pulse applied at the start is applied to the mercury-enclosed high-pressure discharge lamp. This is because a higher voltage of 9 kV or higher is required, and a withstand voltage that can withstand such a high voltage is required.

  Furthermore, the distance between the high-voltage pulse generator and the high-pressure discharge lamp should be a maximum of 500 mm or less. At this distance, the attenuation of the high voltage pulse is relatively small. However, the minimum distance varies in proportion to the rated lamp power of the high-pressure discharge lamp. That is, 60 mm is preferable for the rated lamp power of 50 to 150 W, 80 mm for 150 to 400 W, and 130 mm for 400 to 1000 W. If the distance is shorter than this, inconveniences such as being affected by the heat of the high-pressure discharge lamp tend to occur.

  Furthermore, the high-voltage generator and the high-pressure discharge lamp are mechanically coupled to facilitate handling. As an example of such a case, for example, a socket of a high-pressure discharge lamp and a high voltage generation circuit are integrated to mechanically couple them.

  According to the present invention, it has practical electrical and luminous characteristics without substantially enclosing mercury and mercury substitute materials, that is, halides for forming a lamp voltage, has a small color deviation, and has improved life characteristics, In addition, it is possible to provide a high-pressure discharge lamp that does not have a problem in pellet manufacturing and a lighting device including the same.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

    FIG. 1 is a cross-sectional view showing a first embodiment for carrying out the high-pressure discharge lamp of the present invention. The high-pressure discharge lamp of this embodiment is a metal halide lamp that can be applied to various uses such as for general lighting and automobile headlamps. The translucent hermetic vessel 1, the pair of electrodes 2, and the pair of current introduction conductors 3. 3, a pair of sealing materials 4, 4 and an ionization medium. In addition, each said component is assembled | attached as needed and integrated and comprises the arc_tube | light_emitting_tube IT, and it seals in the outer tube | pipe which has abbreviate | omitted illustration, and uses it.

  The translucent airtight container 1 is made of translucent ceramics, for example, translucent polycrystalline alumina ceramics. And it is provided with the surrounding part 1a and a pair of small diameter cylindrical parts 1b and 1b, and has comprised the integrally molded structure. The surrounding portion 1a has a bowl shape, and includes an intermediate cylindrical portion and a pair of hemispherical portions continuous to both ends thereof. The small-diameter cylindrical portion 1b has an elongated pipe shape, and the tip communicates with the central portion of the hemispherical portion of the surrounding portion 1a.

  The electrode 2 is composed of a rod-like body of doped tungsten, the tip faces the inside of the surrounding portion 1a of the translucent ceramic hermetic container 1, the base end is butt welded to the tip of the current introduction conductor 3, and the middle portion is a small diameter cylinder. The capillary 1b is inserted while forming a capillary that is a slight gap around the inside of the shaped portion 1b.

  The current introduction conductor 3 includes a sealing portion 3a and a halogen-resistant portion 3b connected in series. The sealing portion 3a is composed of a two-obed rod-like body, seals the translucent airtight container 1 in cooperation with a sealing material 4 to be described later, and has a base end outside the translucent airtight container 1. Is exposed. The halogen-resistant portion 3b is made of a molybdenum rod-like body, and its base end is butt welded to the distal end of the sealing portion 3a and inserted into the small-diameter cylindrical portion 1b of the translucent airtight container 1. Moreover, the base end of the electrode 2 is welded to the front-end | tip part.

  The sealing material 4 is made of a frit glass, that is, a melted and solidified body of a ceramic compound, and enters the small-diameter cylindrical portion 1b, and the sealing portion 3a and the small-diameter cylinder of the current introduction conductor 3 positioned in the small-diameter cylindrical portion 1b. It fills the gap between the inner surface of the shaped part 1b and surrounds the surface of the sealing part 3a so as not to be exposed in the translucent airtight container 1.

  The ionization medium is composed of a metal halide and a rare gas.

  The metal halide contains at least one halide of thulium and holmium in a proportion of 30% by mass or more based on the total halide. Further, it does not contain a metal halide or metal having an ionization energy of 8 eV or more and a melting point of 500 ° C. or less.

  The rare gas is made of xenon at 3 atmospheres or more in terms of room temperature (25 ° C.).

  Example 1 is a metal halide lamp shown in FIG.

Translucent airtight container: Integrated molding, enclosure length 8mm, maximum inner diameter 2.9mm, wall thickness 0.5mm, total length 34mm
Pair of electrodes: Distance between electrodes 4.2mm
Ionization medium: TmI ₃ -NaI (75: 25% by mass) = 2 mg, Xe13 atm,
Electrical characteristics: Lamp voltage 55V, lamp power 30W
Luminous properties: Luminous efficiency 97 lm / W
Color deviation duv .: 0.0030

Ionization medium: HoI ₃ —NaI (75: 25% by mass) = 2 mg, Xe13 atm Other than that of Example 1.

Electrical characteristics: Lamp voltage 52V, lamp power 30W
Luminous characteristics: Luminous efficiency 94 lm / W
Color deviation duv .: 0.0020

[Comparative Example 1]
Ionization medium: TmI ₃ —NaI (75: 25% by mass) = 1 mg, ZnI ₂ = 1 mg, Xe 13 atm Other than that of Example 1.

Electrical characteristics: Lamp voltage 70V, lamp power 30W
Luminous characteristics: Luminous efficiency 100 lm / W
Color deviation duv .: 0.0070

Ionization medium: TmI ₃ -NaI (75: 25% by mass) = 2 mg, Xe5 atm,
Others are the same as Example 1.

Electrical characteristics: Lamp voltage 40V, lamp power 30W
Luminous properties: Luminous efficiency 87 lm / W
Color deviation duv .: 0.0050

Ionization medium: TmI ₃ -NaI-TlI (40: 40: 20% by mass) = 2 mg, Xe13 atm,
Electrical characteristics: Lamp voltage 45V, lamp power 30W
Luminous properties: Luminous efficiency 97 lm / W
Color deviation duv .: 0.0080

Examples 1 and 2 are common in that the ionization medium does not contain ZnI ₂ as compared with Comparative Example 1, but the lamp voltage does not reach that of Comparative Example 1, but is within a range that can be sufficiently put into practical use. It is. Further, it can be said that the luminous efficiency is almost the same as that of Comparative Example 1. Further, the color deviation is very good as compared with the comparative example. In particular, in the case of Example 2 in which holmium halide is encapsulated, the color deviation is much smaller.

  In Example 3, the xenon sealing pressure is reduced to 5 atm compared to Example 1, and both the lamp voltage and the light emission efficiency are lower than those of Example 1, but are within a practical range. Further, although the color deviation is larger than that of the first embodiment, it is clearly smaller than that of the first comparative example.

  Example 4 is different from Example 1 in that TlI is added to the halide. Both the lamp voltage and the light emission efficiency are somewhat low, but are within a sufficiently practical range. However, the color deviation is slightly inferior to that of Comparative Example 1.

    FIG. 2 is a graph showing the relationship between the inclusion ratio of thulium halide, lamp voltage, and luminous efficiency. In the figure, the horizontal axis represents the encapsulation ratio (mass%) of thulium halide to all halides, the vertical axis represents the lamp voltage (V) on the right side, and the luminous efficiency lm / W on the left side. Further, in the curves in the figure, the measurement point ■ indicates the lamp voltage, and ◆ indicates the luminous efficiency.

  As can be understood from the figure, with respect to the lamp voltage, a practical lamp voltage can be obtained if the encapsulation ratio of thulium halide is 30% or more. On the other hand, if it is less than 30%, the lamp voltage is too low to be practical.

  In addition, the luminous efficiency is high and practical luminous efficiency can be obtained if the inclusion ratio of thulium halide is 30% or more. On the other hand, when the encapsulation ratio is less than 30%, the light emission efficiency is drastically decreased, which is not practical.

    FIG. 3 is a graph showing the relationship between the sealed pressure of xenon, the lamp voltage, and the luminous efficiency. In the figure, the horizontal axis represents the enclosed pressure (atmospheric pressure) of xenon, the vertical axis represents the lamp voltage (V) on the right side, and the luminous efficiency lm / W on the left side. Further, in the curves in the figure, the measurement point ■ indicates the lamp voltage, and ◆ indicates the luminous efficiency.

  As can be understood from the figure, with regard to the lamp voltage, a practical lamp voltage can be obtained if the enclosed pressure of xenon is 3 atm or more. On the other hand, if the pressure is less than 3 atm, the lamp voltage decreases rapidly and a practical lamp voltage cannot be obtained.

  Regarding the luminous efficiency, if the enclosed pressure of xenon is 3 atm or higher, the luminous efficiency becomes high and practical luminous efficiency can be obtained. On the other hand, when the sealing ratio is less than 3 atm, the luminous efficiency is drastically lowered, and a required lamp voltage cannot be obtained, which is not practical.

    FIG. 4 is a front view showing a second embodiment for carrying out the high-pressure discharge lamp of the present invention. In the figure, the same parts as those in FIG. This embodiment is a metal halide lamp with a rated lamp power of 100 W, and the arc tube IT is accommodated in the outer tube OT. In the figure, SG is shroud glass, SF is an arc tube support member, G is a getter, and B is a base.

  The outer tube OT uses a T-shaped bulb made of hard glass. Then, members such as the arc tube IT, the shroud glass SG, and the arc tube support member SF are housed in predetermined positions. Further, the outer tube OT is provided with a flare stem 5 sealed at a neck portion located at the lower portion in the drawing. The flare stem 5 is provided with a pair of internal lead-in wires 6a and 6b protruding in an airtight manner into the outer tube OT.

  The arc tube IT has the same configuration as that shown in FIG. The upper current introduction conductor 3 is welded and supported by a connection piece 10 described later, and is connected to the internal introduction line 6a via the arc tube support member SF. In addition, the arc tube IT has a lower current introduction conductor 3 welded to and supported by the connection conductor 7, and is connected to the internal introduction line 6 b via the connection conductor 7.

  The shroud glass SG is formed of a quartz glass cylindrical body, surrounds the arc tube IT in a separated state, and is supported by the arc tube support member SF as described later.

  The arc tube support member SF includes a support frame 8, a pair of support plates 9 and 9, and a connection piece 10. The support frame 8 is formed by bending a stainless steel rod into a vertically long U-shape and is connected to the internal lead-in wire 6a. The pair of support plates 9, 9 are formed of a stainless steel plate in a substantially disk shape and are fixed to the support frame 8. In addition, a through hole is formed in the center part of the pair of support plates 9, and by inserting the pair of small diameter cylindrical parts 1 b, 1 b of the translucent airtight container 1 through the through hole, the arc tube IT Is placed at the tube axis position of the outer tube OT, and the arc tube IT is supported in the tube axis direction. The connection piece 10 is welded to the upper part of the support frame 8, and is connected to the upper current introduction conductor 3 in the figure of the arc tube IT. The pair of support plates 9 and 9 are fitted to the upper and lower end surfaces of the shroud glass SG so as to sandwich the shroud glass SG therebetween, and are fixed to the arc tube support member SF. Accordingly, the shroud glass SG is supported by the arc tube support member SF via the pair of support plates 9 and 9.

  The getter G is a performance getter supported at the upper part in the figure of the arc tube support member SF.

  The base B is made of an E26 type screw base, is attached to the neck portion of the outer tube OT, and is connected to the pair of internal lead-in wires 6a and 6b through the outer tube OT in an airtight manner.

Example 5 is a metal halide lamp shown in FIG.
Translucent airtight container: Integrated molding, enclosure length 18mm, maximum inner diameter 10mm, wall thickness 0.7mm, total length 40mm
Pair of electrodes: 10 mm distance between electrodes
Ionization medium: TmI ₃ —NaI (75: 25% by mass) = 4 mg, Xe13 atm,
Electrical characteristics: Lamp voltage 70V, lamp power 100W
Luminous properties: Luminous efficiency 97 lm / W
Color deviation duv .: 0.0030

According to Example 5, the ionization medium is the same as Example 1, but the lamp voltage is 70V.

    FIG. 5 is a cross-sectional view showing a ceiling-embedded downlight as an embodiment for carrying out the lighting device of the present invention.

  In the figure, 11 is a high-pressure discharge lamp, and 12 is a lighting fixture body.

  The high pressure discharge lamp 11 is the same as that in the second embodiment for implementing the high pressure discharge lamp of the present invention shown in FIG.

  The luminaire main body 12 constitutes a ceiling-embedded downlight, and includes a base 12a and a reflector 12b. Since the base 12a is embedded in the ceiling, the base 12a has a ceiling contact edge 12a1 at the lower end. The reflection plate 12b is supported by the base body 12a and surrounds the light emission center of the high-pressure discharge lamp 11 so that it is located at substantially the focal point.

  A high-pressure discharge lamp lighting device (not shown) for lighting the high-pressure discharge lamp 11 is disposed on the lighting fixture body 12 or at a position adjacent to the lighting fixture body 12 or a remote position. It can be set separately.

Sectional drawing which shows the 1st form for implementing the high pressure discharge lamp of this invention Graph showing the relationship between the thulium halide encapsulation ratio, lamp voltage and luminous efficiency Graph showing the relationship between xenon sealing pressure, lamp voltage and luminous efficiency The front view which shows the 2nd form for implementing the high pressure discharge lamp of this invention Sectional drawing which shows the ceiling embedded downlight as one form for implementing the illuminating device of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Translucent airtight container, 1a ... Enclosing part, 1b ... Small diameter cylinder part, 1c ... Discharge space, 2 ... Electrode, 3 ... Current introduction conductor, 3a ... Sealing part, 3b ... Halogen-resistant part, 4 ... Sealing material

Claims (6)

A translucent airtight container having a discharge space therein;
A discharge generating means for generating a discharge in the discharge space of the translucent airtight container;
The metal halide contains a metal halide and a rare gas, and the metal halide contains at least one halide of thulium (Tm) and holmium (Ho) having an encapsulation ratio of 30% by mass or more with respect to all the metal halides enclosed. A noble gas is xenon (Xe) of 3 atm or more at 25 ° C., and an ionization medium enclosed in a translucent airtight container;
A high-pressure discharge lamp comprising: a metal halide for forming a lamp voltage and mercury substantially not contained in a light-transmitting hermetic container.   The high-pressure discharge lamp according to claim 1, wherein the metal halide or metal for forming the lamp voltage has an ionization energy of 8 eV or more and a melting point of 500 ° C or less.   The ionization medium contains at least one halide of thulium (Tm) and holmium (Ho) having an encapsulation ratio with respect to all metal halides of 50% by mass or more. High pressure discharge lamp.   4. The ionization medium contains at least one halide of thulium (Tm) and holmium (Ho) whose encapsulation ratio to all metal halides is 80% by mass or less. A high-pressure discharge lamp according to claim 1.   The high-pressure discharge lamp according to any one of claims 1 to 4, wherein the ionization medium contains xenon of 5 atm or more. A lighting device body;
A high-pressure discharge lamp according to any one of claims 1 to 5 disposed in a lighting device body;
A lighting device for lighting the high-pressure discharge lamp;
An illumination device comprising:

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