JP2002245969A - High pressure electric discharge lamp and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high pressure electric discharge lamp furnished with an electric discharge container a surrounding part to surround at least an electric discharge space of which is made of translucent ceramics, restrain lowering of luminous efficacy by improving heat balance of the electric discharge container and maintaining temperature of the coldest part at a high value, prevent crack growth of a sealed part and to provide a lighting system using this high pressure electric discharge lamp. SOLUTION: This high pressure electric discharge lamp is furnished with the electric discharge container 1 the surrounding part 1a to surround at least the electric discharge space of which is made of translucent ceramics and furnished with a pair of small diametrical cylinder parts 1b, 1c communicated to the surrounding part and arranged on both ends of the surrounding part, a pair of electrodes 2A, 2B inserted into the inside of the small diametrical cylinder parts 1b, 1c and to form a small clearance (g) between themselves and their inner surfaces and an electric discharge medium sealed in the electric discharge container 1, and heat transfer resistance of a pair of the small diametrical cylinder parts 1b, 1c is made different from each other. It is possible to reduce the heat transfer resistance of the small diametrical cylinder part 1c by increasing a cross-section area or an outer diameter of the small diametrical cylinder part 1c, reducing length or combining both of them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-pressure discharge lamp in which at least a surrounding portion of a discharge vessel is made of translucent ceramics, and a lighting device using the same.

[0002]

2. Description of the Related Art By using translucent ceramics for a discharge vessel of an arc tube, a metal halide lamp having high efficiency, high color rendering and long life has been realized, and a lamp adapted to a mercury lamp ballast has been developed. Since this type of conventional high-pressure discharge lamp is a universal type in which the lighting direction is not regulated, a pair of small-diameter cylindrical portions are integrated at both ends of an enclosure in which the discharge vessel surrounds the discharge space, and
It is formed symmetrically.

[0003] However, in the case of this type of high-pressure discharge lamp, when the lamp power exceeds 200 W, the characteristics vary greatly when the lighting direction is changed. This is because, because the distance between the electrodes is increased, the amount of arc bending increases at the time of horizontal lighting, the lamp voltage increases, and gas convection in the outer tube when the gas is sealed in the outer tube. Is changing. For this reason, high-pressure discharge lamps with regulated lighting directions have also been commercialized.

However, in vertical lighting, if the discharge vessel has a symmetrical structure in the direction of the tube axis, that is, vertically, the temperature of the coldest part formed at the lower portion of the discharge vessel decreases, and light emission occurs. There is a problem that efficiency is reduced.

In horizontal lighting, if the discharge vessel has a symmetrical structure in the tube axis direction, the heat balance between the right and left sides of the arc tube deteriorates due to the convection of the sealed gas in the outer tube, and the temperature of the coldest part decreases. Therefore, there is a problem that the luminous efficiency is reduced.

The present invention improves the heat balance of a discharge vessel in which at least an enclosing portion surrounding a discharge space is made of a translucent ceramic, maintains a high luminous efficiency, and prevents cracks in a sealed portion. It is an object of the present invention to provide a high-pressure discharge lamp and a lighting device using the same.

[0006]

According to the first aspect of the present invention, there is provided a high-pressure discharge lamp having a surrounding portion surrounding a discharge space and having a smaller inner diameter than the surrounding portion and having different thermal resistances. A discharge vessel comprising a pair of small-diameter cylindrical portions having at least a surrounding portion made of a translucent ceramic;
A pair of electrodes, which are inserted into the small-diameter cylindrical portion while forming a small gap between the inner surface of the small-diameter cylindrical portion of the discharge vessel and whose distal end faces the surrounding portion of the discharge vessel. It is characterized by:

In the present invention and each of the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified. Hereinafter, each component of the discharge vessel, the pair of electrodes, and the discharge medium will be described.

<Discharge Vessel> The discharge vessel has an enclosing portion and a pair of small-diameter cylindrical portions. The enclosure surrounds the discharge space and thus primarily the positive column that occurs between the electrodes during lighting. In addition, the enclosing portion allows various shapes such as a spherical shape, an elliptical spherical shape, and a spindle shape. The small-diameter cylindrical portions are formed at both ends of the surrounding portion to seal the discharge vessel,
By supporting a pair of electrodes and inserting the electrodes into the inside of the small-diameter cylinder, a slight gap is formed between the inner surface and the electrodes.

Further, in the present invention, at least a main portion of the surrounding portion is formed of a translucent ceramic. Further, if necessary, the small-diameter cylindrical portion can be formed integrally with the surrounding portion from a light-transmitting ceramic. here,
"Translucent ceramics" refers to single crystal metal oxides such as sapphire, polycrystalline metal oxides such as translucent hermetic aluminum oxide, yttrium-aluminum-garnet (YAG), yttrium oxide (Y
OX) and a material having light transmittance and heat resistance, such as a polycrystalline non-oxide such as aluminum nitride (AlN). Note that the term “light-transmitting” means light-transmitting to the extent that light generated by electric discharge can be transmitted to the outside and may be not only transparent but also light-diffusing.

Next, in the case of manufacturing a discharge vessel in which the surrounding portion and the pair of small-diameter cylindrical portions are both made of translucent ceramics, a central surrounding portion and small-diameter cylindrical tubes located at both ends of the surrounding portion are provided. And the sphere part forming the surrounding part and the small-diameter cylinder body forming the small-diameter cylinder part connected to both ends of the sphere part, respectively, and then temporarily sintered, and then joined as required. Then, it can be formed by so-called shrink fitting in which the whole is sintered. In the case of shrink fitting, for example, a tubular body forming an enclosing portion, a pair of end plates fitted and closed on both end surfaces of the tubular body, and a small-diameter fitted in a center hole of the end plate. It is also possible to temporarily sinter the small-diameter cylindrical bodies forming the cylindrical part separately and fit them as required, thereby sintering the whole.

In the present invention, the pair of small-diameter cylindrical portions have different heat transfer resistances. That is, a characteristic configuration is provided in which the heat transfer resistance of one small-diameter cylindrical portion is relatively large and is set smaller than the heat transfer resistance of the other small-diameter cylindrical portion. The heat transfer resistance of the small-diameter tube portion changes as a function of the cross-sectional area of the thick portion of the small-diameter tube portion or the outer diameter and length when the material of the pair of small-diameter tube portions is the same. The heat transfer resistance is inversely proportional to the cross-sectional area or the outer diameter, and is proportional to the length. Therefore, in order to set the heat transfer resistance relatively small, the cross-sectional area or the outer diameter of the thick portion of the small-diameter tube portion is increased, the length of the small-diameter tube portion is reduced, or the thick portion of the small-diameter tube portion is reduced. It is sufficient to increase the cross-sectional area or the outer diameter and decrease the length. In addition, "the cross-sectional area of the small-diameter cylindrical part"
"" Means the cross-sectional area of the thick portion of the small-diameter cylindrical portion.

Further, the small-diameter cylindrical portion is not only made of a light-transmitting ceramic as described above, but may be made of a substantially light-shielding ceramic, cermet, refractory metal such as molybdenum, if necessary. It may be tungsten or the like. Further, the constituent material of the small-diameter cylindrical portion may be different between the upper and lower parts.

In order to seal the discharge vessel, when the small-diameter cylindrical portion is made of ceramic or cermet, a sealing portion formed by heating and melting a ceramic sealing compound between the small-diameter cylindrical portion and the introducing conductor. By forming
You can do this. In other words, a ceramic sealing compound is applied between the introduced conductor and the small-diameter tube at the end face of the small-diameter tube, which is melted by heating, penetrated between the small-diameter tube and the introduced conductor, and solidified by cooling. By doing so, a seal is formed and the airtight seal between them is provided. The introduction conductor is fixed at a predetermined position by this seal. It is desirable that the seal is completely covered so that at least the sealing portion of the introduction conductor is not exposed in the small-diameter cylindrical portion. Furthermore, if the seal is configured so as to cover the base end of the electrode fixed to the leading end of the lead-in conductor over a small distance, preferably 0.2 to 3 mm, the lead-in conductor discharges halide and the like. It is hardly corroded by the medium.

When the small-diameter cylindrical portion is made of a refractory metal, the surrounding portion and the small-diameter cylindrical portion can be hermetically joined using, for example, a joining layer mainly composed of cermet. Note that a relatively short cylindrical seat can be formed at a portion of the surrounding portion that receives the small-diameter cylindrical portion, in order to ensure a required joint area with the small-diameter cylindrical portion. Further, the space between the small-diameter cylindrical portion and the introduction conductor can be sealed by welding.

<Regarding the pair of electrodes> The pair of electrodes uses tungsten or doped tungsten as a material, and the middle is inserted into the small-diameter cylindrical portion to form a small gap between the pair of electrodes and the inner surface of the small-diameter cylindrical portion. At the same time, the tip faces the enclosure. The phrase “facing the surrounding portion” includes both a mode located in the surrounding portion and a mode not located in the surrounding portion but positioned in the small-diameter cylindrical portion so as to generate a discharge in the surrounding portion. is there. Further, the electrode may have a structure adapted to any of AC lighting and DC lighting. In the AC lighting method, a pair of electrodes can be formed by a refractory metal rod, but in the DC lighting method, the cathode is formed by a refractory metal rod, and the anode can be formed at least at the tip part thicker than the cathode. .

The tip of the electrode may be wound with a tungsten coil as needed to increase the surface area and improve heat dissipation. The middle portion of the electrode is desirably of a certain thickness in order to form a small gap or capillary as uniform as possible between the inner surface of the small diameter cylindrical portion. Also, if necessary, in the middle of the electrode,
Wrap a relatively thin metal wire made of refractory metal,
A ceramic tube can be fitted. The base end of the electrode is electrically and mechanically supported by being fixed to an introduction conductor described later by welding or the like.

<Discharge Medium> The discharge medium contains at least a rare gas such as argon as a starting gas and a buffer gas, and is sealed in a discharge vessel so as to exhibit a pressure of about 1 atm or more during lighting. In addition, as the discharge medium, a metal halide and / or mercury can be used as a luminescent substance or a buffer vapor, if necessary.

When a metal halide is used for the discharge medium, iodine and bromine can be mainly used as the halogen constituting the metal halide. The metal halide of the luminescent metal has a luminescent color and an average color rendering index Ra.
In addition, in order to obtain radiation having desired luminous characteristics with respect to luminous efficiency, etc., it can be arbitrarily selected from known metal halides according to the size and input power of the discharge vessel. One example is sodium N
One or a plurality of halides selected from the group consisting of a, thallium Tl, and a rare earth metal such as dysprosium Dy can be used.

Further, instead of an appropriate amount of mercury as a buffer vapor, a metal having a relatively high vapor pressure and low luminescence in the visible light region, or a non-luminous metal such as aluminum, zinc,
A halide such as tin or iron can be enclosed.

<Other Configurations> Although not an essential component of the present invention, by adding the following configuration as required, the manufacture of the high-pressure discharge lamp becomes easy and the functions are enhanced. .

1. Introduction conductor In order to externally supply power to the electrodes in the discharge vessel, the introduction conductor can be hermetically led out of the small-diameter cylindrical portion of the discharge vessel. That is, the introductory conductor is a conductor that applies voltage between the electrodes, supplies current to the electrodes, and functions to seal the discharge vessel. The leading end is connected to the base end of the electrode. Are exposed outside the translucent discharge vessel. Further, by supporting a portion of the introduction conductor led out of the discharge vessel to the outside, it may be used to support the entire high-pressure discharge lamp.

In the case where the small-diameter cylindrical portion of the discharge vessel is formed of a translucent ceramic, the introduction conductor is a conductive metal having a thermal expansion coefficient similar to that of the translucent ceramic as a sealing portion. Certain niobium, tantalum, titanium, zirconium, hafnium and vanadium can be used. When aluminum oxide such as alumina ceramic is used as the translucent ceramic, niobium and tantalum are suitable for sealing because the average thermal expansion coefficient is almost the same as that of aluminum oxide. The difference is also small for yttrium oxide and YAG. In the case of using aluminum nitride, zirconium is preferably used for the introduction conductor. The term "sealing portion" refers to a portion between the small-diameter cylindrical portion of the discharge vessel and the sealing portion by a seal, or, if necessary, a portion for sealing with a ceramic tube interposed therebetween. Say.

Further, a refractory part can be connected to the leading end of the sealing part, if desired, to the introduction conductor. The refractory portion may be molybdenum, tungsten or a cermet containing one or more of these as a component. Further, when a tungsten rod is used for the refractory portion, the tip of the tungsten rod can be used as an electrode. The `` refractory portion '' is a portion made of a conductive material having a high melting point enough to withstand high temperatures during operation of the high-pressure discharge lamp and having corrosion resistance to a discharge medium present in the discharge vessel. is there.

Further, it is possible to comprise at least a sealing metal formed by shaping the introduction conductor into an appropriate shape such as a rod-like body such as niobium, a pipe-like body or a coil-like body. In addition, since niobium and the like have a strong oxidizing property, when the high-pressure discharge lamp is lit in a state of being exposed to the atmosphere, an oxidation-resistant conductor is further connected to the sealing portion of the introduction conductor, and the sealing portion is also connected. Must be covered with, for example, a seal so as not to come into contact with the atmosphere.

(2) Outer tube When an outer tube is used, a high-pressure discharge lamp provided with a discharge vessel, a pair of electrodes and a discharge medium accommodated therein acts as an arc tube. And a high-pressure discharge lamp is constituted including the outer tube. The outer tube can be used for mechanically protecting the arc tube and maintaining the operating temperature of the arc tube in a desired range. The inside of the outer tube can be evacuated and filled with a vacuum or low pressure or an inert gas such as a rare gas or nitrogen as required. The outer tube can be made of a material having appropriate translucency, airtightness, heat resistance and workability, for example, hard glass.

Further, the outer tube is made of a material so as to satisfy a predetermined condition in a relative thermal relationship with a seal of a ceramic sealing compound used for sealing the discharge vessel and the introduced conductor. , Sealing structure and size are set.

When the outer tube is hermetically sealed, either one-sided sealing or both-sided sealing can be employed if desired. Note that "single sealing" refers to a structure in which a pinch seal portion is formed only at one end of an outer tube, and the other end is closed without forming a sealing portion. On the other hand, “both ends sealed” refers to a structure in which pinch seal portions are formed at both ends of the outer tube. When the outer tube has a single sealed structure, it is suitable for aligning the axis of the high-pressure discharge lamp with its optical axis when the high-pressure discharge lamp is used in combination with a reflecting mirror. Further, the both-end sealing structure is suitable for disposing the optical axis of the reflecting mirror and the axis of the high-pressure discharge lamp at right angles.

3. Starter In order to start the high-pressure discharge lamp using, for example, a mercury lamp ballast and to stably operate the discharge lamp, a starter can be incorporated. The starter performs a rapid switching operation at power-on, thereby generating a high voltage pulse from the ballast and applying it to the high pressure discharge lamp to facilitate starting. In order to perform a rapid switching operation, the starter is provided with switching means such as a glow starter, a bimetal switch or a non-linear capacitor.

3 Regarding the starting auxiliary conductor In order to further reduce the starting voltage of the high-pressure discharge lamp, a starting auxiliary conductor can be arranged close to the outside of the discharge vessel. That is, the starting auxiliary conductor has its base end connected to the same potential as that of one of the electrodes, and has its front end extended to a position close to the other electrode while its middle is close to the surrounding portion of the discharge vessel.

<Operation of the present invention> In the high-pressure discharge lamp of the present invention, the heat transfer resistances of the pair of small-diameter cylindrical portions provided in the discharge vessel are different from each other. If the electric heat resistance of the small-diameter cylindrical portion on the side is reduced, the temperature of the small-diameter cylindrical portion is easily increased, and therefore, the temperature of the coldest portion of the discharge vessel is prevented from lowering. Therefore, the luminous efficiency can be maintained at a high value. In addition, by increasing the heat transfer resistance of the small-diameter cylindrical portion that is on the upper side during lighting of the discharge vessel to be larger than the heat transfer resistance of the small-diameter cylindrical portion that is on the lower side during lighting, the sealing portion of the small-diameter cylindrical portion that is on the upper side during lighting is formed. It is easy to suppress a rise in temperature, so that it is possible to prevent cracks from being generated in the sealing portion of the small-diameter cylindrical portion that is on the upper side during lighting.

Further, even in horizontal lighting, if the temperature of one of the pair of small-diameter cylinders becomes relatively lower than that of the other, the heat transfer resistance of one of the small-diameter cylinders is reduced to thereby reduce the small-diameter cylinder. Since the temperature of the cylindrical portion increases, the heat balance of the discharge vessel can be improved, and a decrease in luminous efficiency can be suppressed. Similarly, if the temperature of the other small-diameter cylinder is relatively high, the temperature of the small-diameter cylinder is decreased by increasing the heat transfer resistance of the other small-diameter cylinder, so that the heat balance of the discharge vessel is reduced. It is possible to prevent the occurrence of cracks.

The present invention is suitable for a high-pressure discharge lamp with a lamp power of 200 W or more, but is not limited to this.

According to a second aspect of the present invention, there is provided a high-pressure discharge lamp according to the first aspect, wherein the discharge vessel is configured such that at least one of the outer diameter and the length of the pair of small-diameter cylindrical portions is relatively different. The heat transfer resistance of the pair of small-diameter cylindrical portions is set to a predetermined value.

According to the present invention, the heat transfer resistance of the small-diameter cylindrical portion is reduced.
At least one of the outer diameter and length of
The required configuration is specified. Of a pair of small diameter cylinders
Heat transfer resistance of small-diameter cylinder required by making outer diameter relatively different
When setting, for example, in vertical lighting, the lower small
The outer diameter of the cylindrical part is d_L, The upper outside diameter is d_UAnd the ratio of the two
To d_U/ D_LThen, 0.4 ≦ d_U/ D_L<1.0
A range is preferred. d _U/ D_LIs less than 0.4,
Cracks occur because the upper small-diameter tube becomes thinner
Easier to do. Also, d_U/ D_LIs 1.0 or more
And the heat transfer resistance of the lower small-diameter cylinder
I can't do that.

Next, when the heat transfer resistance of the small-diameter tube portion is set to a desired value by making the lengths of the pair of small-diameter tube portions relatively different, for example, in vertical lighting, the lower length of the small-diameter tube portion is reduced. To L
_L, the upper lengths _{L U,} if both the ratio between _{L L} / _{L U,} is preferably in a range of _{0.3 ≦ L L / L U ≦} 0.7. The “length of the small-diameter cylindrical portion” refers to the length of a portion protruding from the surrounding portion to the outside. When L _L / L _U is less than 0.3, the upper and lower sealing conditions are too different, and the amount of heat diffusion to the surrounding portion side becomes large, particularly at the time of lower sealing, and the sealing failure is likely to occur. Become. On the other hand, when L _L / L _U exceeds 0.7, the heat transfer resistance of the lower small-diameter cylindrical portion cannot be reduced as required. When the outer diameter and the length of the small-diameter cylindrical portion are both different, they can be appropriately combined within the above range.

Thus, in the present invention, at least one of the outer diameter and the length of the small-diameter cylindrical portion only needs to be changed, so that the heat transfer resistance can be easily set as required.

According to a third aspect of the present invention, in the high-pressure discharge lamp according to the first or second aspect, the discharge vessel has a pair of small-diameter cylindrical portions whose inner diameters are substantially equal and whose outer diameters are relatively small. Therefore, the heat transfer resistance of the small-diameter cylindrical portion is set to a predetermined value.

In the present invention, since the inside diameters of the pair of small-diameter cylindrical portions are substantially equal, members having the same diameter can be used for the pair of electrodes, and the design of a small gap called a capillary is easy. become. In addition, you may combine with making the length of a small diameter cylindrical part different.

A high-pressure discharge lamp according to a fourth aspect of the present invention comprises an enclosing portion surrounding the discharge space and a pair of sealing portions located at both ends of the enclosing portion, wherein at least the enclosing portion is made of a translucent ceramic. A pair of electrodes having an elongated shaft portion, the base end of which is supported by the sealing portion of the discharge vessel, the distal end facing the surrounding portion, and the elongated shaft portions having different diameters from each other; And;

The present invention specifies a configuration different from the above-described invention for improving the heat balance of the discharge vessel of the high-pressure discharge lamp by making the diameters of the elongated shaft portions of the pair of electrodes different from each other. That is, by increasing the diameter of the elongated shaft portion of one electrode, the heat transfer resistance of the electrode is reduced, and the amount of heat transfer from the other electrode to the opposing sealing portion is increased. Therefore, the heat balance of the discharge vessel can be improved irrespective of the lighting direction, so that a decrease in luminous efficiency can be suppressed. In the present invention, a small-diameter cylindrical portion in which a small gap is formed may not be provided.

On the other hand, by reducing the diameter of the elongated shaft portion of the electrode, the heat transfer resistance of the electrode increases, and the amount of heat transfer from the electrode to the opposing sealing portion decreases. For this reason, it is possible to prevent the temperature of the sealing portion from rising excessively and suppress the occurrence of cracks in the sealing portion.

According to a fifth aspect of the present invention, there is provided a lighting device, comprising: a lighting device main body; a high-pressure discharge lamp according to any one of claims 1 to 4 provided in the lighting device main body; And a ballast for stably lighting the high-pressure discharge lamp interposed in series with the ballast.

In the present invention, the lighting device is a broad concept including any device that uses the light emission of a high-pressure discharge lamp for some purpose. For example, lighting equipment, image projection devices,
It can be applied to photochemical devices and the like.

The "illumination device main body" refers to the remaining portion excluding the high-pressure discharge lamp from the illumination device.

When the lighting device is a lighting fixture, the lighting device body may be provided with a ballast and a lamp socket, and the lamp socket may be provided with a high-pressure discharge lamp. . However, the ballast can also be located separately from the luminaire.

[0046]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing a first embodiment of the high-pressure discharge lamp of the present invention.

In the figure, the high-pressure discharge lamp HPL has a structure suitable for vertical lighting, and includes a discharge vessel 1, an upper electrode 2A, a lower electrode 2B, a pair of introduction conductors 3, 3, a pair of seals 4A, 4B, and It has a discharge medium sealed inside the discharge vessel 1 and has a vertically asymmetric structure.

<Regarding the Discharge Vessel 1> The discharge vessel 1 is made of translucent alumina ceramics, and has a surrounding portion 1a and an upper small-diameter cylindrical portion 1 provided in communication with both ends of the surrounding portion 1a.
b and a lower small-diameter cylindrical portion 1c. The discharge vessel 1 is integrated by shrink-fitting the upper small-diameter cylindrical portion 1b and the lower small-diameter cylindrical portion 1c to the surrounding portion 1a. Note that the upper small-diameter tube portion 1b is on the upper side during lighting, and the lower small-diameter tube portion 1c is on the lower side.

The surrounding portion 1a has a substantially elliptical spherical shape having a continuous curved surface, and has an insertion seat 1a for an upper small-diameter cylindrical portion 1b and a lower small-diameter cylindrical portion 1c whose both ends are narrowed and communicate with each other.
1, 1a2 are formed.

Upper small-diameter cylindrical portion 1b and lower small-diameter cylindrical portion 1c
Each have a pipe-like shape, and the surrounding portion 1 has a corresponding tip.
a is inserted into the insertion seats 1a1 and 1a2. The upper small-diameter cylindrical portion 1b has a relatively small outer diameter, and is formed with a large length protruding from the surrounding portion 1a. On the other hand, the lower small-diameter cylindrical portion 1c has a relatively large outer diameter, and the length of a portion protruding from the surrounding portion 1a is formed to be small. However, the inner diameters of the through holes of the upper small-diameter cylindrical portion 1b and the lower small-diameter cylindrical portion 1c are equal.

<About upper electrode 2A and lower electrode 2B>
The upper electrode 2A is made of doped tungsten and includes an elongated shaft portion 2Aa, a tip coil portion 2Ab, and an intermediate coil portion 2Ac. The elongated shaft portion 2Aa is inserted into the upper small-diameter cylindrical portion 1b. The tip coil portion 2Ab protrudes into the surrounding portion 1a. The intermediate coil portion 2Ac forms a slight gap g between the intermediate coil portion 2Ac and the inner surface of the upper small-diameter cylindrical portion 1Ab.

The lower electrode 2B is made of doped tungsten similarly to the upper electrode 2A, and has an elongated shaft portion 2Ba, a tip coil portion 2Bb, and an intermediate coil portion 2Bc. The elongated shaft portion 2Ba is inserted into the upper small-diameter cylindrical portion 1c. The tip coil portion 2Bb protrudes into the surrounding portion 1a. The intermediate coil portion 2Bc forms a slight gap g between the intermediate coil portion 2Bc and the inner surface of the upper small-diameter cylindrical portion 1c.

<Regarding the pair of introduction conductors 3 and 3> The pair of introduction conductors 3 and 3 each form a rod-shaped body made of niobium, and the tip ends are an upper small-diameter cylindrical portion 1b and a lower small-diameter cylindrical portion 1c.
And the base end protrudes out of the discharge vessel 1. At the tips of the pair of introduction conductors 3, 3, the elongated shaft portions 2A of the upper electrode 2A and the lower electrode 2B are provided.
The base ends of a and 2Ba are welded.

<Regarding the pair of seals 4A and 4B> Each of the pair of seals 4A and 4B is formed by melting and solidifying a ceramic sealing compound. Then, the discharge vessel 1 is hermetically sealed by being interposed between the end face side portions of the upper small-diameter cylindrical portion 1b and the lower electrode 1c of the discharge vessel 1 and the introduction conductors 3 and 3 opposed thereto. Thus, while providing a so-called introduction conductor insertion / sealing structure, the entire portion inserted into the small-diameter cylindrical portions 1b and 1c is covered so that the introduction conductors 3 and 3 are not exposed inside the discharge vessel 1. . Thus, the upper electrode 2A and the lower electrode 2B are fixed at predetermined positions of the discharge vessel 1 by the above sealing.

To form the seals 4A and 4B,
The discharge vessel 1 is set in a vertical position, and a ring-shaped pellet (not shown) of a compound for sealing ceramics.
Is placed on the end surface of the upper small-diameter cylindrical portion 1b or the lower small-diameter cylindrical portion 1c to be sealed, and the ring-shaped pellet is heated and melted to introduce the conductor 3 and the upper small-diameter cylindrical portion 1b or the lower side. It is made to enter into the gap between the inner surfaces of the small-diameter cylindrical portion 1c to cover the entirety of the introduction conductor 3 inserted into the upper small-diameter cylindrical portion 1b or the lower small-diameter cylindrical portion 1c, and further to the upper electrode 2A or the lower electrode. The base end of the elongated shaft 2Aa or 2Ba of the electrode 2B is also covered.

<Discharge Medium> The discharge medium is composed of argon as a starting gas and a buffer gas, a metal halide as a luminescent metal, and mercury as a buffer vapor. I have.

Further, since the metal halide and mercury are enclosed more than the amount that evaporates, a part thereof is formed in the upper small-diameter cylindrical portion 1b and the lower small-diameter cylindrical portion 1c during stable lighting. It stays in the gap g in a liquid phase state.
Then, the surface of the discharge medium staying in the liquid phase state in the lower small-diameter cylindrical portion 1c forms the coldest portion.

Embodiment 1 Upper small-diameter cylindrical portion 1b: outer diameter 4 mm, inner diameter 2 m
m, length 25 mm Lower small-diameter cylinder 1c: outer diameter 5.6 mm, inner diameter 2 mm, length 10 mm Discharge medium: Na, Tl, Dy, In-I system Lamp power: 100 W (Comparative Example 1) Upper small-diameter cylinder 1b: outer diameter 4 mm, inner diameter 2 mm, length 25
mm Lower small-diameter cylindrical portion 1c: outer diameter 4mm, inner diameter 2mm, length 25
mm The discharge medium, lamp power and other configurations are as described in Example 1.
Same as (Comparative Example 2) Upper small-diameter cylindrical portion 1b: outer diameter 5.6 mm, inner diameter 2 mm, length 10 mm Lower lower-diameter cylindrical portion 1c: outer diameter 5.6 mm, inner diameter 2 mm, length 10 mm Discharge medium, lamp power and Other configurations are described in Example 1.
<Measurement results> Table 1 shows the results of measuring the lamp characteristics by lighting each of Example 1 and Comparative Examples 1 and 2 connected to a 200 V commercial AC power supply via a mercury lamp ballast. Was.

[0059]

Table 1 Item Example 1 Comparative Example 1 Comparative Example 2 Luminous Efficiency (lm / W): 95 78 89 Average Color Rendering Index (Ra): 91 75 92 Others * *: 100-hour lighting, upper small-diameter cylinder Cracks occurred in the car and made a point.

Embodiment 2 Upper small-diameter cylindrical portion 1b: outer diameter 1.5mm, inner diameter 1mm, length 25mm Lower lower-diameter cylindrical portion 1c: outer diameter 2.5mm, inner diameter 1mm, length 15mm Discharge medium: Na, Tl, In -I system Lamp power: 220 W (Comparative example) Upper small-diameter cylindrical portion 1b: outer diameter 1.5 mm, inner diameter 1 mm, length 25 mm Lower lower-diameter cylindrical portion 1c: outer diameter 1.5 mm, inner diameter 1 mm, length 25 mm Discharge medium , Lamp power and other configurations are described in Example 2.
<Measurement Results> The results of measuring the lamp characteristics by lighting each of Example 2 and Comparative Example via a mercury lamp ballast by connecting them to a 200 V commercial AC power supply are as shown in Table 2.

[0060]

[Table 2] FIG. 2 is a longitudinal sectional view showing a high-pressure discharge lamp according to a second embodiment of the present invention.

In the figure, the same parts as those in FIG. In this embodiment, the elongated shaft portions 2Aa and 2A of the upper electrode 2A and the lower electrode 2B
The diameters of Ba are made different from each other so that the temperature of the coldest part formed below the discharge vessel 1 is maintained at a high value, and the temperature rise of the sealing part of the upper small-diameter cylindrical part 1b is suppressed. They differ in that they do.

In the discharge vessel 1, the surrounding portion 1a, the upper small-diameter cylindrical portion 1b and the lower small-diameter cylindrical portion 1c are formed by integral molding, and the upper small-diameter cylindrical portion 1b and the lower small-diameter cylindrical portion 1c are formed. They have the same outer diameter and length. Further, the thickness of the central portion of the surrounding portion 1a is relatively thin, so that the transmittance of light emission due to discharge is increased.

Embodiment 3 Upper electrode 2A: outer diameter of elongated shaft portion 2Aa 0.25 mm, diameter of coil material 0.2 mm, tip coil portion 2Ab diameter 0.65 mm Lower electrode: outer diameter of shaft portion 2Ba 0.3 mm , Diameter of coil material 0.25 mm, diameter of tip coil portion 2Bb 0.8 m
m, discharge medium: Na, Tl, Dy, In-I system Lamp power: 250 W (comparative example) Upper electrode 2A: outer diameter of shaft portion 2Aa 0.25 mm, coil material diameter 0.2 mm, tip coil portion 2Ab 0.6 diameter
5 mm, lower electrode: outer diameter of shaft portion 2Ba 0.25 mm, diameter of coil material 0.2 mm, diameter of tip coil portion 2Bb 0.65 m
m Discharge medium, lamp power and other configurations are described in Example 3.
<Measurement results> Table 3 shows the results obtained by connecting each of Example 3 and Comparative Example to a 200 V commercial AC power supply via a mercury lamp stabilizer and lighting the lamps to measure the lamp characteristics.

[0063]

[Table 3] FIG. 3 is a front view showing a third embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is a circuit diagram showing an internal electrical connection and a high pressure discharge lamp lighting circuit.

In each figure, the same parts as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. This embodiment is different in that an outer tube 12 with a base is provided. That is, the high-pressure discharge lamp HPL includes an arc tube 11, an outer tube 12, and a base 1.
3, a supporting structure 14, a connecting conductor 15, a starter 16, a starting auxiliary conductor 17, and a getter 18.
The high pressure discharge lamp lighting circuit includes a mercury lamp ballast B between the 200 V commercial AC power supply AS and the high pressure discharge lamp HPL.
Are arranged in series.

<Regarding the Arc Tube 11> The arc tube 11 is composed of the high-pressure discharge lamp shown in FIG.

<Regarding Outer Tube 12> The outer tube 12 is made of hard glass and has a BT shape having a spindle-shaped bulging portion at the center, a neck at the upper end, and a short cylindrical head at the lower end. The neck portion is provided with a flare stem 12a sealed. The flare stem 12a has a pair of lead-in wires 12a.
1, 12a2 are introduced in an airtight manner.

<Regarding Base 13> The base 3 is an E39 type base, which is fixed to the neck of the outer tube 2 and one of a pair of introduction wires 12a1 and 12a2 exposed to the outside from the outer tube 12 is provided on the shell. The other is connected to the center contact.

<Regarding the Supporting Structure 14>
Comprises a frame-shaped conductor 14a, a first bridge conductor 14b, insulators 14c and 14d, a first metal band 14e, a second bridge conductor 14f, a second metal band 14g, and a spring piece 14h.

The frame-shaped conductor 14a has a vertically long rectangular shape, and the lead-in wire 12 sealed to the flare stem 12a is formed.
The upper part is electrically connected to a1 by welding, and is mechanically supported. The arc tube 11 is located inside the frame-shaped conductor 14a.

The first bridge conductor 14b is insulated at both ends of the frame-shaped conductor 14a through insulators 14c and 14d with both ends insulated, and has a central portion curved upward.

In the first metal band 14e, the power supply conductor 11c on the upper part of the arc tube 11 is sandwiched by an intermediate portion by welding, and both ends are welded to the first bridge conductor 14b.
Thus, the upper part of the arc tube 11 is supported by the support structure 14.

The second bridge conductor 14f is bridged by welding both ends thereof directly to the lower portion of the frame-shaped conductor 14a, and has a central portion curved downward.

The second metal band 14g has a power supply conductor 11c at the upper portion of the arc tube 11 sandwiched by welding at an intermediate portion thereof, and both ends are welded to the first bridge conductor 14b.
Thus, the lower part of the arc tube 11 is supported by the support structure 14.

One pair of the spring pieces 14h is welded to both sides of the lower end of the frame-shaped conductor 14a, and elastically contacts the inner surface of the short cylindrical head at the lower end of the outer tube 12. Thereby, the lower end of the frame-shaped conductor 14 a is supported by the outer tube 12.

<Regarding Connection Conductor 15> Connection Conductor 15
Is composed of a ribbon-shaped conductor, and connects between the introduction wire 12a2 and the first bridge conductor 14b. This allows
The introduction line 12a2 is connected to the arc tube 1 via the connection conductor 15, the first bridge conductor 14b, and the first metal band 14e.
1 is connected to the upper power supply conductor 11c. In addition, introduction line 1
2a1 is a frame-shaped conductor 14a, a second bridge conductor 14f
And a metal band 14g to the power supply conductor 11c below the arc tube 11.

<Regarding the Starter 16> The starter 16 includes a glow starter 16a, a bimetal contact 16b, connection conductors 16c, 16d, 16e, a ceramic substrate 16f, and a metal ring 16g. ing.

(Regarding Glow Starter 16a) The glow starter 16a includes a glow discharge vessel, a pair of electrodes, a discharge medium, and external introduction wires 3 and 4. The glow discharge vessel is made of a soft glass that reduces Fe ₂ O ₃ and substantially transmits ultraviolet rays having a wavelength of 300 nm or less due to rare gas discharge, and is manufactured by sealing a T-shaped bulb and a flare stem. The pair of electrodes are made of a bimetallic plate, and the base ends thereof are welded to the distal end of the internal introduction wire of the flare stem, and are opposed to each other while being separated from each other. Argon is sealed as an ionization medium in the glow discharge vessel.

The external introduction wires 3 and 4 are connected to a dumet wire sealed in a pinch seal portion of the glow discharge vessel in a state where a pair thereof is separated from each other, and protrude from the glow discharge vessel to the outside. The external lead 3 is a frame-shaped conductor 1
4a, and the external introduction line 4 is connected to the connection conductor 16c.

(About the bimetal contact 16b) The base end of the bimetal contact 16b is welded to the connection conductor 16c, and the free end comes into contact with and separates from the connection conductor 16d.

(Connection conductors 16c, 16d, 16e) The connection conductors 16c, 16d, 16e are fixed to the ceramic substrate 16f in an insulating relationship with each other. The connection conductor 16d is further welded to the first bridge conductor 14b. The connection conductor 16e is further welded to the frame-shaped conductor 14a.

(Ceramic Substrate 16f) The ceramic substrate 16f is disposed so that its plate surface is orthogonal to the tube axis of the outer tube 12, and is supported by the support structure 14 by connection conductors 16e and 16d.

(Metal Ring 16g) The metal ring 16g is welded to the frame-shaped conductor 14a and encloses the glow starter 16a.

<Regarding the Starting Auxiliary Conductor 17> The starting auxiliary conductor 17 is provided to assist the starting of the arc tube 11. That is, the arc tube 11 includes the pair of electrodes as described above and does not include the auxiliary electrode, but includes the starting auxiliary conductor 17. The starting auxiliary conductor 17 is made of a thin metal wire, the upper end of which is welded to the frame-shaped conductor 14a in the figure, and the middle is wound twice around the upper small-diameter cylindrical portion 11b of the discharge vessel 11a, and then approaches the right side of the surrounding portion 11a1 in FIG. To extend downward, and the tip is further reduced to the lower small-diameter cylindrical portion 11c.
And wound once.

<Regarding Getter 18> The getter 18 cleans the inside of the outer tube 12, and is welded to a lower portion of the frame-shaped conductor 14a.

FIG. 5 is a partially central sectional front view showing a recessed downlight as one embodiment of the lighting device of the present invention.

In the figure, the same parts as those in FIG. 3 are denoted by the same reference numerals, and the description is omitted.

The embedded downlight of this embodiment comprises an embedded downlight body 21 and a high-pressure discharge lamp HPL. In addition, the ballast (not shown) is configured to be separately placed at a position separated from the embedded downlight main body 21.

The embedded downlight main body 21 is
a, a lamp socket 21b, a reflector 21c, a reflector support 21d, and a decorative frame 21e.

The support frame 21a comprises an annular frame 21a1 and a U-shaped frame 21a2. The annular frame 21a1 is provided with a locking flange f on the outer periphery of the lower part thereof, and is arranged in a state fitted to the mounting hole BB of the ceiling board by mounting means (not shown). The locking flange f comes into contact with the ceiling board when the annular frame 21a1 is fitted into the mounting hole BB of the ceiling board. The U-shaped frame 21a2 is fixed to the annular frame 21a1 so as to straddle the annular frame 21a1.

The lamp socket 21b is disposed in the support frame 21a at the center of the upper lower surface of the U-shaped frame 21a2.

The reflecting mirror 21c has a paraboloid of revolution reflecting surface, and has a lamp insertion opening at the center of the top,
Each has a light projecting opening on the lower surface. Then, the light projecting opening is located in the annular frame 21a1.

[0093] The reflector support 21d is fixed to a U-shaped frame 21a2 at a position adjacent to the lamp insertion opening of the reflector 21c, which is located on both sides of the lamp socket 21b.

The decorative frame 21e is attached to the annular frame 21a1, and adjusts the appearance of the mounting holes BB of the ceiling board.

The high-pressure discharge lamp HPL is the same as that shown in FIG. 3, and can be mounted on the lamp socket from below the ceiling board.

[0096]

According to each of the first to third aspects of the present invention, the discharge vessel includes the surrounding portion and a pair of small-diameter cylindrical portions disposed at both ends of the surrounding portion, and surrounds at least the discharge space. Is made of translucent ceramics, and the heat transfer resistance of the pair of small-diameter cylindrical portions is different from each other, so that the heat balance of the discharge vessel can be improved. It is possible to provide a high-pressure discharge lamp in which a decrease in efficiency is suppressed and a crack in the sealing portion is prevented.

According to the second aspect of the present invention, in addition, at least one of the outer diameter and the length of the pair of small-diameter cylindrical portions of the discharge vessel is different, so that the pair of small-diameter cylindrical portions have different heat transfer resistances. A high pressure discharge lamp can be provided.

According to the third aspect of the present invention, in addition, since the inner diameters of the pair of small-diameter cylindrical portions of the discharge vessel are substantially equal and the outer diameters are different, if the heat transfer resistances of the pair of small-diameter cylindrical portions are different from each other. To provide a high pressure discharge lamp.

According to the fourth aspect of the present invention, the pair of electrodes has an elongated shaft portion, the base ends of the elongated shaft portions are supported by the sealing portions located at both ends of the discharge vessel, and the distal end is the surrounding portion. As the diameter of one elongated shaft is relatively larger than the diameter of the other elongated shaft, the amount of heat transferred through the elongated shaft of the electrode is relatively increased, and the heat of the discharge vessel is increased. It is possible to provide a high-pressure discharge lamp in which the balance can be improved, the temperature of the coldest part is maintained at a required high level, the decrease in luminous efficiency is suppressed, and the occurrence of cracks in the sealed part is prevented.

According to the fifth aspect of the present invention, it is possible to provide a lighting device having the effects of the first to fourth aspects.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of a high-pressure discharge lamp of the present invention.

FIG. 2 is a longitudinal sectional view showing a second embodiment of the high-pressure discharge lamp of the present invention.

FIG. 3 is a front view showing a third embodiment of the high-pressure discharge lamp of the present invention.

FIG. 4 is a circuit diagram showing an internal electric connection and a high pressure discharge lamp lighting circuit.

FIG. 5 is a partially sectional front view showing a recessed downlight as one embodiment of the lighting device of the present invention;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Discharge container 1a1 ... Insert seat 1a2 ... Insert seat 1b ... Upper small diameter cylinder part 1c ... Lower small diameter cylinder part 2A ... Upper electrode 2Aa ... Slender shaft part 2Ab ... Tip coil part 2Ac ... Intermediate coil part 2B ... Lower electrode 2Ba ... Elongated shaft 2Bb ... Coil end 2Bc ... Intermediate coil 3 ... Introduction conductor 4 ... Seal g ... Slight gap HPL ... High pressure discharge lamp

Continuation of front page (72) Inventor Masazumi Ishida 4-3-1 Higashishinagawa, Shinagawa-ku, Tokyo Toshiba Litec Corporation F-term (reference) 5C043 AA02 AA14 CC02 CD01 CD05 DD03 DD11 DD15 EA01

Claims (5)

[Claims] 1. An enclosure surrounding a discharge space, and a pair of small-diameter cylinders disposed in communication with both ends of the enclosure and having a smaller inner diameter than the enclosure and having different thermal resistances, and at least the enclosure is transparent. A discharge vessel made of conductive ceramics;
A pair of electrodes, which are inserted into the small-diameter cylindrical portion while forming a small gap between the inner surface of the small-diameter cylindrical portion of the discharge vessel and whose distal end faces the surrounding portion of the discharge vessel. A high pressure discharge lamp characterized by the above-mentioned. 2. The discharge vessel according to claim 1, wherein at least one of the outer diameter and the length of the pair of small-diameter cylindrical portions is relatively different, so that the heat transfer resistance of the pair of small-diameter cylindrical portions is set to a predetermined value. The high-pressure discharge lamp according to claim 1, wherein: 3. The discharge vessel has a pair of small-diameter cylindrical portions whose inner diameters are substantially equal and whose outer diameters are relatively different.
3. The high-pressure discharge lamp according to claim 1, wherein the heat transfer resistance of the pair of small-diameter cylindrical portions is set to a predetermined value. 4. A discharge vessel comprising: a surrounding portion surrounding a discharge space; and a pair of sealing portions located at both ends of the surrounding portion, wherein at least the surrounding portion is made of translucent ceramics; A pair of electrodes whose base end is supported by the sealing portion of the discharge vessel and whose tip faces the surrounding portion, and whose elongated shafts have different diameters from each other. High-pressure discharge lamp characterized. 5. An illumination device main body; a high-pressure discharge lamp according to any one of claims 1 to 4 disposed in the illumination device main body; A ballast for stably lighting the discharge lamp.