JP4510670B2 - High pressure discharge lamp - Google Patents

Description

  The present invention relates to a high pressure discharge lamp comprising an improved translucent ceramic discharge vessel.

  A metal halide lamp including a translucent ceramic discharge vessel in which a surrounding portion defining a discharge space and a pair of small diameter cylindrical portions extending in the tube axis direction from both ends of the surrounding portion are integrally formed is known (for example, (See Patent Document 1). In a translucent ceramic discharge vessel used in a conventional metal halide lamp of the related art, the small diameter cylindrical portion generally has a substantially constant thickness. Moreover, what has become a little thick in the junction part of a small diameter cylinder part and an enclosure part is also known (for example, refer patent document 2).

The above translucent ceramic discharge vessel is called a so-called integral molded bulb, and is compared with a so-called shrink-fit translucent ceramic discharge vessel formed by firing by combining a plurality of members having a fitting structure. Therefore, it is frequently used because of its high mechanical strength and excellent characteristics.
JP 2004-349242 A JP 2004-055140 A

  However, as for the integrally formed bulb | bulb described in patent document 1 and 2, all are the parts where the junction part of the small diameter cylindrical part and surrounding part of a translucent ceramic discharge vessel is the most fragile, and during manufacture and transportation Could be damaged. If it adds about the case of patent document 2, although the site | part which is a little thick in the junction part of a small diameter cylinder part and an enclosure part may act effectively in pouring of the ceramic material in a shaping | molding die. It is not always effective to increase the strength of the joint between the small-diameter cylindrical portion and the surrounding portion.

As a cause of damage to the translucent ceramic discharge vessel, it is considered that the influence of erosion by the discharge medium is large. The region on the discharge space side of the small-diameter cylindrical portion easily reacts with the enclosed discharge medium because the discharge medium stays and the operating temperature is high. For this reason, the region is easily eroded by the discharge medium.

  However, in the above-described configuration, which has been known in the past, the joint between the electrode and the power supply member faces the constant thickness region of the small diameter cylindrical portion. Even if the thickness of the joint portion is larger than that of the small-diameter cylindrical portion, the portion remains at a slight length and cannot necessarily effectively act against the above-mentioned erosion.

  It is a general object of the present invention to provide a high-pressure discharge lamp including a translucent ceramic discharge vessel having an improved structure of a small diameter cylindrical portion.

  Another object of the present invention is to provide a high-pressure discharge lamp including a translucent ceramic discharge vessel whose strength is improved by improving the structure of the small-diameter cylindrical portion.

  Another object of the present invention is to provide a high-pressure discharge lamp including a translucent ceramic discharge vessel that has an effect of preventing leakage of the seal portion by improving the small-diameter cylindrical portion.

The high-pressure discharge lamp of the present invention includes a surrounding portion that surrounds the discharge space and a small-diameter cylindrical portion that is disposed at both ends of the surrounding portion and has a smaller inner diameter than the surrounding portion, and the surrounding portion and the small-diameter cylindrical portion are integrally formed, and In the region where the small-diameter cylindrical portion has at least two types of thickness and has a substantial length continuous to the surrounding portion, a thick portion having a relatively large thickness is formed. A pair of translucent ceramic discharge containers that are inserted into the small-diameter cylindrical part while forming a slight gap between the base end side and the inner surface of the small-diameter cylindrical part of the translucent ceramic discharge container, with the tip facing the discharge space A power supply member having a distal end portion inserted into the small diameter cylindrical portion and connected to the proximal end of the electrode, and the proximal end portion exposed to the outside from the small diameter cylindrical portion; A sealing material for hermetically sealing the photoceramic discharge vessel; A discharge medium sealed in the La mix discharge vessel; equipped with, is characterized in that the connection portion of the electrode and the feeding member is opposed to the thick portion of the small diameter cylinder portion continuous with the surrounding portion.

  The present invention comprises a translucent ceramic discharge vessel, a pair of electrodes, a power supply member, a sealing material and a discharge medium as described above, and the definitions and technical meanings of terms are as follows unless otherwise specified. .

  <Translucent Ceramic Discharge Container> The translucent ceramic discharge container is composed of a single crystal metal oxide, for example, sapphire, and a polycrystalline metal oxide, for example, translucent airtight aluminum oxide, yttrium-aluminum-garnet. This is a discharge vessel made of a material having optical transparency and heat resistance such as (YAG), yttrium oxide (YOX), and polycrystalline non-oxide, for example, aluminum nitride (AlN). Note that the translucency means that the visible light generated by the discharge can be transmitted to the outside and transmitted to the outside, and is preferably transparent, but if necessary, it is light diffusive. Also good. And at least the surrounding part should just be provided with translucency.

  The translucent ceramic discharge vessel includes an enclosing portion that surrounds the discharge space, and a pair of small-diameter cylindrical portions that are disposed in communication with the ends of the enclosing portion. And the surrounding part and the small diameter cylinder part are integrally formed by integrally molding and sintering.

  The surrounding portion is allowed to form an inner surface of the surrounding portion into a continuous curved surface so as to surround the discharge and define a discharge space therein. Furthermore, the main part inside the surrounding part can be made hollow with a bowl shape, an elliptical spherical shape, a spherical shape, or the like. The “main part” of the surrounding part refers to a part of the remainder excluding the vicinity of the end part on the side in contact with the small-diameter cylindrical part, and a part through which light emission by discharge is mainly transmitted.

  The small-diameter cylindrical part is inserted in a later-described electrode and a power supply member connected to the electrode, and a slight gap called a capillary is formed around the middle part of the electrode so that it does not evaporate inside. A discharge medium such as a metal halide or mercury that stays in the metal enters and forms the coldest part on the surface of the discharge space. Further, the capillary can be configured to reduce the temperature of the seal portion to a required value by forming a temperature gradient in the length direction thereof, so that the capillary can be sealed against the translucent ceramic discharge vessel. To contribute effectively.

  The small-diameter cylindrical portion has at least two types of thickness, and forms a thick portion having a relatively large thickness in a region having a substantial length continuous with the surrounding portion. The portion having at least two types of thickness is preferably formed along the axial direction of the small diameter cylindrical portion.

  When the thick part protrudes from the outer surface of the small-diameter cylindrical part in the radial direction of the small-diameter cylindrical part, the thick part and the thin part adjacent thereto are connected while being inclined by a continuous curved surface. Can be configured. That is, the cross-sectional shape of the outer surface of the thick part draws a convex curve from the thick part to the thin part, and further draws a concave curve toward the thin part. It should be noted that the curvature of the concave curve can be reduced so that the distance between the convex curve and the concave curve is substantially linear.

  As one aspect of the portion having at least two types of thickness, the inner diameter of the elongated hole formed inside the small diameter cylindrical portion is formed in a constant state. As another aspect, in the region facing the thin portion, the inner diameter of the elongated hole formed inside the small diameter cylindrical portion is formed to be larger than the inner diameter of the other region. As yet another aspect, in the region facing the thick portion, the inner diameter of the elongated hole formed inside the small diameter cylindrical portion is larger than the inner diameter of the other region.

  In the above description, the “region having a substantial length continuous with the surrounding portion” is different from the concept of a joint portion between the surrounding portion and the small-diameter cylindrical portion, and clearly corresponds to a part of the small-diameter cylindrical portion. This is a region that can be said, and it means that the region has an axial length that is at least sufficiently recognizable. Therefore, a connecting portion between an electrode and a power feeding member, which will be described later, is disposed at a position facing the thick portion.

In addition to the above, if desired, a part or the whole of the portion having at least two types of wall thickness may be formed in association with changing the inner diameter of the elongated hole along the axial direction. . For example, a relatively thin portion can be formed by increasing the inner diameter of a partial region along the axial direction of the elongated hole. Moreover, while increasing the internal diameter of the partial area | region along the axial direction of the said elongate hole, the thickness of the said area | region can also be enlarged. Furthermore, at least two types of wall thickness are provided in the small-diameter cylindrical portion by changing the inner diameter of a partial region along the axial direction of the elongated hole in a state where the outer diameter is kept constant over substantially the entire length of the small-diameter cylindrical portion. Can be formed.

  In addition, it is preferable that the high pressure discharge lamp is designed so that the temperature on the outer surface of the translucent ceramic discharge vessel during lighting is 850 to 1200 ° C.

  <About a pair of electrodes> A pair of electrodes is sealed inside a translucent ceramic discharge vessel with its distal end facing the discharge space and its intermediate portion and proximal end portion inserted into the small diameter cylindrical portion, As a result, they face each other across the discharge space. It is made of a metal having halogen resistance and fire resistance such as tungsten or rhenium.

  In addition, the electrode can have a structure including an electrode shaft and an electrode coil. In this case, the base end of the electrode shaft constitutes the base end of the electrode. The electrode coil is disposed near the tip of the electrode shaft by being wound around the tip of the electrode shaft. In this case, the tip of the electrode shaft can be configured to protrude from the tip of the electrode coil toward the discharge space.

  Furthermore, the electrode shaft coil can be provided by winding the electrode shaft coil around a portion inserted into the small diameter cylindrical portion of the electrode, for example, the electrode shaft. In this case, the electrode shaft coil is located inside the capillary.

  <About the power supply member> The power supply member is a member having a function for supplying power to the electrode, a function for sealing the translucent ceramic discharge container in cooperation with the small-diameter cylindrical portion and the seal member, and a function for supporting the electrode. . Then, the base end portion is exposed to the outside from the end portion of the small diameter cylindrical portion and connected to the lighting circuit, and the tip end portion is connected to the base end of the electrode. The distal end portion of the power supply member is inserted into the small diameter cylindrical portion of the translucent ceramic discharge vessel, and is further connected to the base end of the electrode inside the small diameter cylindrical portion.

Further, the feeding member, the diameter of the portion adjacent to the proximal end of at least the electrode is inserted into the small diameter cylindrical portion is at least the proximal portion of the electrode can preferably be configured to be greater than the diameter of the electrode shaft . Thereby, the diameter of an electrode or an electrode axis | shaft can be set to the optimal size, without being influenced by the diameter of a feed part . However, in this configuration, as described later in the prior art tend to entailment erosion rate retention of the discharge medium in the gap around the connection portion of the feeding member and the electrode is increased, according to the present invention the Since the connecting portion faces the thick portion, the erosion rate is reduced.

  Further, the whole power supply member may be formed of a sealing conductive member, or may be formed of a series connection structure of a sealing conductive member and a halogen-resistant conductive member. In the former case, it is a matter of course that the sealing conductive member takes into account the above three functions. On the other hand, in the latter case, the sealing conductive member takes charge of the function of sealing the translucent ceramic discharge vessel in cooperation with the small-diameter cylindrical portion and the sealing material described later. Takes charge of the function of supporting the electrodes, and both members take charge of the function of supplying power to the electrodes. The halogen-resistant conductive member can be constituted by a series connection structure of a plurality of element members.

  As the sealing conductive member, a conductive member having a thermal expansion coefficient close to that of the electrode is preferably used. For example, niobium (Nb), tantalum (Ta), platinum (Pt), or the like can be used depending on the type of translucent ceramic. Niobium is preferred when the translucent ceramic discharge vessel is made of translucent alumina ceramics.

  As the halogen-resistant conductive member, it is preferable to use a material having fire resistance that can withstand heat transfer from the electrode and a thermal expansion coefficient close to the electrode constituent material. For example, it can be selected from tungsten (W), molybdenum (Mo), cermet and the like. The cermet is formed by firing a mixture of ceramic particles and refractory conductive metal (for example, Mo or W) powder. When the halogen-resistant conductive member is constituted by a series connection structure of a plurality of element members, the plurality of element members connected in series are different halogen-resistant conductors, for example, a molybdenum rod-shaped body or a tungsten rod-shaped body, and a cermet rod-shaped body. It is allowed to be constituted by.

  In order to connect the electrode to the power supply member to support the electrode and to facilitate the assembly of the translucent ceramic discharge vessel, for example, the two can be integrated in advance by butt welding to constitute an electrode mount. Further, when the power supply member is formed of a sealing conductive member and a halogen-resistant conductive member, they can be integrated by butt welding.

Contact Itewa the present invention, the connecting section of the power supply member and the electrode, arranged so as to face the thick portion continuous to the surrounding portion of the small diameter cylinder portion of the translucent ceramic discharge vessel.

<About the sealing material> The sealing material is made of high melting point frit glass or the like, and enters between the inner surface of the small-diameter cylindrical portion of the translucent ceramic discharge container and the power supply member to hermetically seal the translucent ceramic discharge container. To do. In order to perform this sealing, pellets of a sealing material can be applied to the periphery of the power supply member at the end of the small-diameter cylindrical portion, and can be heated and melted, as is adopted as a general method. If it does so, since the sealing material fuse | melted at high temperature will approach into the slight clearance gap formed between the inner surface of a small diameter cylinder part and an electric power feeding member, it will solidify, and a seal | sticker will be formed. Incidentally, the sealing material, so covering the site to function sealing power supply member, no problem even if a substance having poor halogen resistance as niobium.

  <Regarding Discharge Medium> In the present invention, the structure of the discharge medium is not particularly limited. In the case of obtaining a metal halide lamp, it is configured to include at least a metal halide and a rare gas. Further, mercury can be included as a medium for forming the lamp voltage. When mercury is used as a medium for forming a lamp voltage, a luminescent metal halide is mainly used as the metal halide.

  In addition, when mercury is not used as a medium for forming a lamp voltage, and so-called mercury-free is used, in addition to a metal halide and a luminescent metal halide, a metal having a high vapor pressure and low light emission in the visible light region. For example, halides such as zinc (Zn) and aluminum (Al) can be enclosed instead of mercury.

  As a preferred embodiment of the luminescent metal halide, can contain at least one of sodium (Na) and thallium (Tl) halides and rare earth metal halides. A more preferable form in this embodiment is that a halide of sodium (Na), thallium (Tl) and thulium (Tm) is contained as a main component of the luminescent metal halide. In this case, the enclosure ratio of Na, Tl, and Tm halides can be set relatively freely. In addition, about the halide of sodium (Na), thallium (Tl), and thulium (Tm), it can be enclosed according to the description of patent document 1. FIG.

  Further, calcium (Ca) halide can be encapsulated as a metal halide together with the above luminescent metal or other luminescent metal halide. In this case, the encapsulation ratio is 1 to 40% by mass. Calcium (Ca) halide, when added, effectively acts to adjust the chromaticity of red and blue. In addition, it is allowed to adjust the chromaticity of light emission by adding an appropriate amount of any one or a plurality of halides of indium (In), lithium (Li) and rubidium (Rb) in addition to Ca. .

  When the rare gas is sealed as the starting gas and the buffer gas, the gas is not limited to a specific rare gas. For example, a mixed gas of neon and argon can be sealed. Generally, it is preferable to enclose about 8.0 to 80 kPa. If it is less than 8.0 kPa, it is difficult to start discharge as shown in the Paschen curve. If it exceeds 80 kPa, the starting voltage becomes high and exceeds the pressure resistance of the base.

  <Regarding Rated Power> In the present invention, the rated power of the high-pressure discharge lamp is not particularly limited, but is preferably in the range of 10 W to 1000 W. Optimally, it is 50-500W.

  <Regarding the Action of the Present Invention> In the present invention, as described above for the small-diameter cylindrical portion of the translucent ceramic discharge vessel, the thick-walled portion has a substantial length as the small-diameter cylindrical portion at a position continuous with the surrounding portion. Therefore, the following effects are exhibited.

  1. If the thick part is formed over the region having a substantial length on the enveloping part side of the small diameter cylindrical part, the heat capacity of the thick part increases, so that from the thick part to the end of the small diameter cylindrical part Compared with the case where the temperature is not provided with a thick part, the temperature decreases. As a result, the occurrence of erosion of the small diameter cylindrical portion by the discharge medium is reduced. Therefore, the translucent ceramic discharge vessel can be maintained in a high mechanical strength state for a long period.

2. When the power supply member is constituted by a serial connection structure of a sealing conductive member and a halogen-resistant conductive member composed of a single element member or a plurality of element members connected in series, one or more in the power supply member A first connection is formed. A second connection portion is formed between the electrode and the power supply member. Therefore, the first and second connection portions are formed in the series body of the power feeding member and the electrode. In such a configuration, Ru is disposed at a position where the second connecting portion is opposed to the thick portion continuous to the surrounding portion. In this placement, even if erosion occurs by the discharge medium staying in the gap between the periphery of the second connecting portion opposed to the thick portion of the small diameter cylinder portion, a portion erosion increases relatively wall thickness Therefore, since the thickness of the small-diameter cylindrical portion in the vicinity thereof is large, the translucent ceramic discharge vessel is not damaged to the extent that the mechanical strength is reduced.

  3. Above 1. Deterioration of the sealing material in the sealing portion of the translucent ceramic discharge vessel is reduced by the temperature drop at the end of the small-diameter cylindrical portion described in (1). As a result, leakage of the sealing portion during the life of the high-pressure discharge lamp is effectively prevented, so that the reliability of the sealing portion is increased.

4). As described above, when the diameter of the power feeding portion is set to be relatively larger than at least the base end portion of the electrode, preferably the diameter of the electrode shaft, as described later, generally, the diameter depends on the discharge medium as compared with the case where the diameter of the electrode shaft and the power feeding member is equal erosion increases Suruga, in the present invention, the junction of the conductive polar axis and the feed member by facing the thick portion, erosion rate is reduced.

  5. By connecting the thick part on the side continuous to the surrounding part of the small-diameter cylindrical part and the thin part adjacent to this with a continuous curved surface, distortion occurs at the boundary between the thick part and the thin part. It becomes difficult and the mechanical strength of the said part does not fall.

  6). By relatively increasing the inner diameter of the end-side region of the elongated hole formed inside the small-diameter cylindrical portion, a thick portion can be formed in the remaining region, and in the end-side region, the power supply member The gaps formed around the are increased. Thereby, the sealing material which penetrates into the said clearance gap in a molten state can be increased, and a translucent ceramic discharge vessel sealing can be made still better.

  7). As a preferred embodiment of the discharge medium, by containing at least one of sodium (Na) and thallium (Tl) halides and halides of rare earth metals, highly efficient and stable emission characteristics can be obtained.

  <Other Configurations in the Present Invention> Although not an essential component of the present invention, an outer tube can be added as desired. The outer tube is a means for accommodating the arc tube in an airtight manner. As the atmosphere in the outer tube, vacuum or an inert gas such as nitrogen or argon can be enclosed.

  As the material of the outer tube, hard glass, semi-hard glass, quartz glass and the like are generally used. However, if necessary, the outer tube made of the same translucent ceramic as the arc tube may be used.

  In addition, a base or the like is attached to the outer tube according to a conventional method, and a support frame or the like for supporting the arc tube housed inside is appropriately disposed.

According to the present invention, in the region where the small-diameter cylindrical portion has at least two types of thickness and has a substantial length of the small-diameter cylindrical portion continuous to the surrounding portion, the thickness is relatively large. By forming the portion, the temperature of the small-diameter cylindrical portion is reduced, so that the erosion of the small-diameter cylindrical portion due to the stay of the discharge medium is reduced, and the translucent ceramic discharge vessel is kept in a high mechanical strength state for a long period In addition to being able to maintain the connection portion of the electrode and the power supply member facing the thick portion, even if erosion is caused by the staying discharge medium, the erosion is relatively increased by the connection portion. Since the portion of the small-diameter cylindrical portion is thick, it is possible to provide a high-pressure discharge lamp that is not damaged so that the mechanical strength of the translucent ceramic discharge vessel is reduced .

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

    1 and 2 show a first embodiment for carrying out the high-pressure discharge lamp of the present invention, FIG. 1 is a schematic front view, and FIG. 2 is an enlarged sectional front view of an arc tube. In each figure, the high-pressure discharge lamp CDL is of a 400W type, and includes an arc tube IT, an outer tube OT, a shroud glass SG, an arc tube support member SF, a UV enhancer UVE, getters Ga and Gb, and a base B.

  As shown in FIG. 2, the arc tube IT includes a translucent ceramic discharge vessel 1, a pair of electrodes 2, 2, a pair of power supply members 3, 3, a pair of sealing materials 4, 4 and a translucent ceramic discharge vessel 1. A discharge medium sealed inside. FIG. 1 mainly shows the arrangement of each component, and the characteristic structure of the translucent ceramic discharge vessel 1 is omitted.

  As shown in detail in FIG. 2, the translucent ceramic discharge vessel 1 includes a surrounding portion 1a and a pair of small-diameter cylindrical portions 1b and 1b arranged in communication with both ends of the surrounding portion 1a. A space 1c is provided. The surrounding portion 1a and the pair of small diameter cylindrical portions 1b and 1b are integrated by casting. The encircling portion 1a is a substantially bowl shape in which two spheres are separated in the axial direction so as to partially overlap each other to form hemispherical portions at both ends, and the hemispherical portions are connected by a straight line. It has the shape of The translucent ceramic discharge vessel 1 may have a configuration in which a plurality of ceramic members divided along the tube axis direction are joined and then sintered and integrated.

  The pair of small-diameter cylindrical portions 1b and 1b each have an elongated pipe shape as a whole. And in the area | region which has at least 2 types of thickness along a pipe-axis direction, and has a substantial length which continues to an envelopment part, the thickness part 1b1 with relatively large thickness is formed. Yes. Further, in the remaining region from the thick part 1b1 to the end of the small diameter cylindrical part 1b, a thin part 1b2 which is thinner than the thick part 1b1 is formed. Further, an elongated hole that penetrates in the tube axis direction and communicates with the surrounding portion is formed at the center of the small-diameter cylindrical portion. In this embodiment, the elongated hole has a constant inner diameter.

In the cross section along the tube axis direction, the thick portion 1b1 is continuous with the outer surface of the surrounding portion 1a with one end of the outer surface drawn in a large concave curve. The other end is continuous with the thin portion 1b2 while being inclined as a whole by a relatively large convex curve and a relatively small concave curve. In addition, the boundary part of the surrounding part 1a and a pair of small diameter cylinder parts 1b and 1b forms the curved surface which continued to the surrounding part 1a and a pair of small diameter cylinder part 1b also in the inner surface side.

  The thin part 1b2 is formed in a region up to an intermediate part and an end part of the small diameter cylindrical part 1b.

  The pair of electrodes 2 and 2 includes an electrode shaft 2a, an electrode coil 2b, and an electrode shaft coil 2c. The electrode shaft 2a is made of a solid tungsten rod, the proximal end and the intermediate portion are inserted into the small diameter cylindrical portions 1b and 1b, and the distal end portion is desired in the discharge space 1c. A slight gap of 0.1 mm or less, called a capillary, is formed between the electrode shaft 2a and the inner surfaces of the small diameter cylindrical portions 1b and 1b.

  The electrode coil 2b is formed by winding a thin tungsten wire at a suitable number of dense pitches at a position slightly retracted from the tip of the electrode shaft 2a so that a protruding portion having a slight length is formed at the tip of the electrode shaft 2a. And is located in the surrounding portion 1a.

  The electrode shaft coil 2c is mounted by being wound around the electrode shaft 2a at an appropriate pitch in a region where the electrode shaft 2a is inserted into the small diameter cylindrical portion 1b.

  As shown in FIG. 2, the pair of power supply members 3 and 3 is constituted by a series connection structure of a sealing conductive member 3a and a halogen-resistant conductive member 3b, and the diameter thereof is set larger than that of the electrode shaft 2a. Yes. For this reason, a step is formed at the joint between the electrode shaft 2 a and the power supply member 3.

  The sealing conductive member 3a is made of a niobium rod. The halogen-resistant conductive member 3b is made of a cermet rod-shaped body. The cermet rod-shaped body is formed of a sintered body of molybdenum-alumina. The sealing conductive member 3a has a distal end inserted into the inside thereof from the end of the small diameter cylindrical portion 1b and covered with a sealing material described later, and a base end exposed to the outside of the small diameter cylindrical portion 1b. The halogen-resistant conductive member 3b has a base end that is butt welded to the tip of the sealing conductive member 3a, and a tip that is butt welded to the base end of the electrode shaft 2a to form a series connection structure. Yes.

  Thus, the electrode 2 and the power feeding member 3 are integrated in advance in a straight line to form an electrode mount.

The pair of sealing materials 4 and 4 are formed by heating and melting a ceramic sealing compound called frit glass made of Dy ₂ O ₃ —SiO ₂ —Al ₂ O ₃ , respectively, and solidifying. . Thus, the pair of sealing materials 4, 4 are the sealing conductive members 3 a of the power feeding members 3, 3 facing the portions on the end face side of the small-diameter cylindrical portions 1 b, 1 b of the translucent ceramic discharge vessel 1. The translucent ceramics discharge vessel 1 is hermetically sealed with a so-called power supply member insertion sealing structure. The pair of power supply members 3, 3 cover the entire portion inserted into the small diameter cylindrical portions 1 b, 1 b so as not to be exposed inside the translucent ceramic discharge vessel 1. With the above configuration, the translucent ceramic discharge vessel 1 is sealed, and the electrodes 2 and 2 are fixed at predetermined positions in the translucent ceramic discharge vessel 1.

  In addition, in order to form the sealing material 4, it can follow a conventional method, and the translucent discharge vessel 1 is first set to a vertical position. Next, the ring-like frit glass (not shown) of the ceramic sealing compound is positioned on the upper side at that time, for example, on the small-diameter cylindrical portion 1b side, and the externally exposed portion of the sealing conductive member 3a. Then, it is placed on the end face of the small diameter cylindrical portion 1b, and the ring-shaped pellet is heated and melted. If it does so, the fuse | melted sealing material 4 will approach into the slight clearance gap between the sealing conductive member 3a of the electric power feeding member 3, and the inner surface of the small diameter cylinder part 1b, and will solidify. The sealing material 4 covers the entire portion inserted into the small-diameter cylindrical portion 1b of the sealing conductive member 3a of the power supply member 3 and a part of the base end side of the halogen-resistant conductive member 3b. Next, the translucent ceramic discharge vessel 1 is inverted 180 °, and the sealing material 4 is formed on the other small-diameter cylindrical portion 1b side in the same procedure as described above. In addition, before the latter sealing, the discharge medium mentioned later is enclosed in the translucent inside.

The discharge medium is made of a rare gas, a metal halide, and mercury, and is enclosed in the translucent ceramic discharge vessel 1. Since metal halide and mercury are encapsulated in excess of the amount that evaporates, some of them stay in liquid phase in the small gaps formed in the small diameter cylindrical portions 1b and 1b during lighting. Yes. And the coldest part is formed in the surface layer part vicinity of the discharge medium which stays in the liquid phase state, for example in the small diameter cylinder part 1b used as the lower side during lighting. Metal halide are both mainly emitting metal halide, made for example NaI, TlI, from InI and TmI _3.

  As shown in FIG. 1, the outer tube OT uses a BT 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 a lower portion in FIG. 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 is supported by an arc tube support member SF, which will be described later, on the feeding member 3 on the upper side thereof, and is connected to the internal lead-in line 6a via the arc tube support member SF. Further, the arc tube IT is supported by connecting the lower power supply member 3 to the connection conductors 7 and 8, and is connected to the internal lead-in line 6 b through the connection conductors 7 and 8.

  The shroud glass SG is made of a quartz glass cylinder, surrounds the arc tube IT in a separated state, and is supported by the light tube support member SF as described later. The support body 9 is fitted to the upper and lower end surfaces of the shroud glass SG and is fixed to the arc tube support member SF.

  The arc tube support member SF includes a support frame 11, a pair of support plates 12a and 12b, and a pair of spring pieces 13 and 13. The support frame 11 is formed by bending a stainless steel rod into a vertically long deformed rectangular shape, and further welding a band-shaped conductor 11a in a bridge shape, and is connected to the internal lead-in wire 6a. The pair of support plates 12a and 12b are formed of a stainless steel plate in a substantially disk shape, and sandwich the upper and lower end surfaces of the shroud glass SG from above and below using locking claws formed on the periphery, and in FIG. It is being fixed to the support frame 11 using the attachment nail | claw which protrudes from right and left. In addition, through holes are formed in the center portions of the pair of support plates 12a and 12b, and the arc tube is formed by inserting the pair of small diameter cylindrical portions 1b and 1b of the translucent ceramic discharge vessel 1 through the through holes. IT is fixed at the tube axis position of the outer tube OT, and the arc tube IT is supported mainly in a direction orthogonal to the tube axis. The pair of spring pieces 13 and 13 are welded separately on the left and right in the upper portion of the support frame 11 in FIG. 1, and elastically contact the inner surface of the head of the outer tube OT so that the upper portion of the support frame 11 is removed. It elastically supports the inner surface of the head of the tube OT.

  As is clear from the above, the arc tube support member SF mechanically supports the arc tube IT and the middle tube SG at predetermined positions with respect to the outer tube OT.

  The UV enhancer UVE operates prior to the start of the ceramic discharge lamp CDL to radiate ultraviolet rays and irradiate the arc tube IT, thereby promoting electron emission in the arc tube IT of the ceramic discharge lamp CDL to thereby promote the ceramic discharge lamp. It is a means for facilitating CDL start-up. Since it is known in principle, the detailed structure is not shown, but it is configured to include an airtight container, an introduction wire, an internal electrode, a discharge medium, and an external electrode. The hermetic container is made of ultraviolet transmissive glass such as quartz glass, and has an elongated discharge space formed therein. The lead wire is made of molybdenum, the tip is welded to an internal electrode to be described later, and the base end is welded to the arc tube support member SF, as shown in FIG. 1, and therefore the internal lead wire 6a is connected via the arc tube support member SF. Connected to. The internal electrode is made of molybdenum and has a plate shape, and is sealed in a discharge space of an airtight container. The discharge medium is composed of about 1.3 kPa of argon and is enclosed in an airtight container. The external electrode is made of a molybdenum wire having an outer diameter of 0.4 mm, is tightly wound on the outer periphery of the airtight container and is wound about 5 turns, and is connected to the connection conductor 8 via the conductor 16. As is clear from the above, the UV enhancer UVE is connected in parallel to the arc tube IT.

  The getter Ga is an initial getter that is connected between the arc tube support member SF and the connection conductor 8 and is located near the flare stem 5. The getter Gb is a performance getter supported on the top of the arc tube support member SF.

  The base B is made of an E39 type screw base, and is attached to the neck portion of the outer tube OT, to which the pair of external lead wires are connected.

    FIG. 3 is a graph showing the evaluation of the erosion rate by the acceleration test of the high-pressure discharge lamp according to the first embodiment of the present invention together with that of the comparative example. In the figure, the horizontal axis represents the estimated lighting time (h), and the vertical axis represents the erosion rate (%). Curve A in the figure is the present invention, curve B is Comparative Example 1, and curve C is Comparative Example 2. The specifications of the present invention, Comparative Example 1 and Comparative Example 2 have the structure shown in FIG. 4 and the dimensions shown in Table 1.

FIG. 4 is a cross-sectional view of the main part of the present invention (first embodiment), Comparative Example 1 and Comparative Example 2, wherein (a) is the present invention, (b) is Comparative Example 2 , and (c) is Comparative Example 1. It is. In the figure, the same parts as those in FIG. Comparative Example 2 has the same structure as that of the present invention except that the small-diameter cylindrical portion has no thick portion. Comparative Example 1 has the same structure as Comparative Example 2 except that the power supply member 3 has the same diameter as the electrode shaft.

図３から理解できるように、曲線Ａに示す本発明によれば、小径筒部の侵食が顕著に遅い。これに対して、曲線Ｂに示す比較例１は、本発明に比較して侵食率が明らかに高い割合で発生する。曲線Ｃに示す比較例２においては、侵食率が比較例１のそれよりさらに高い割合で発生する。

As can be understood from FIG. 3, according to the present invention shown by the curve A, the erosion of the small-diameter cylindrical portion is remarkably slow. On the other hand, the comparative example 1 shown by the curve B occurs at a rate that the erosion rate is clearly higher than that of the present invention. In Comparative Example 2 shown by curve C , the erosion rate occurs at a higher rate than that of Comparative Example 1.

FIG. 5 is a graph showing the temperature distribution of each part of the translucent ceramic discharge vessel according to the first embodiment of the present invention together with that of the comparative example. In the figure, the horizontal axis represents the position of each part of the translucent ceramic discharge vessel arranged in the upper part of the graph, and the vertical axis represents the operating temperature (° C.) during lighting. Curve C is the invention according to the solid line in the figure, the curve D that by the dotted line as a comparative example. The comparative example is the same as the comparative example 1 shown in Table 1.

  As can be seen from the figure, according to the present invention, the temperature of the thick portion 1b1 of the small diameter cylindrical portion 1b is lower than that of the comparative example, and the degree of temperature decrease is toward the end of the thin portion 1b2. Become prominent.

    FIG. 6 is a cross-sectional view of an essential part for explaining the relationship between the outer surface shape of the boundary portion between the thick portion and the thin portion of the small diameter cylindrical portion and the defect rate in the first embodiment of the present invention.

  In the figure, the boundary portion between the surrounding portion 1a and the thick portion 1b1 of the small-diameter cylindrical portion 1b forms a continuous curved surface by a large concave curve whose cross-sectional shape in the tube axis direction is formed with a curvature radius R1.

  The boundary between the thick portion 1b1 and the thin portion 1b2 of the small diameter cylindrical portion 1b is formed from the thick portion 1b1 to the thin portion 1b2 by a convex curve formed with an appropriate curvature radius R2 and a concave curve formed with a curvature radius R3. A continuous curved surface inclined downward is formed. Note that the circle in the figure describes the radius of curvature R3.

  Next, referring to Table 2, the relationship between the degree of inclination and the defect rate at the boundary between the thick part 1b1 and the thin part 1b2 of the small diameter cylindrical part 1b will be described. Table 2 shows the degree of inclination with the radius of curvature R3 for convenience. The R value in the table indicates the value of R3, and the defect rate indicates the defect rate during the manufacturing process of the translucent ceramic discharge vessel.

表２によれば、曲率半径Ｒ３が１．５ｍｍ以上では不良率が０％である。表２には示していないが、曲率半径Ｒ３が１．０ｍｍを境に不良率が０％になる。したがって、表２は、小径筒部１ｂの肉厚部１ｂ１と肉薄部１ｂ２との境界部における傾斜が緩やかであれば、不良率が低くなることを意味しているといえる。

According to Table 2, when the radius of curvature R3 is 1.5 mm or more, the defect rate is 0%. Although not shown in Table 2, the defect rate becomes 0% when the curvature radius R3 is 1.0 mm. Therefore, it can be said that Table 2 means that if the slope at the boundary between the thick portion 1b1 and the thin portion 1b2 of the small-diameter cylindrical portion 1b is gentle, the defect rate becomes low.

    FIG. 7 shows another embodiment for carrying out the high-pressure discharge lamp of the present invention in comparison with the first embodiment. FIG. 7 (a) shows the first embodiment, and FIG. 7 (b) shows the second embodiment. FIG. 7C is a sectional view of the main part of the arc tube of the third embodiment. In the figure, the same parts as those in FIG. Further, the translucent ceramic discharge vessel is shown on the left side of the figure, and the arc tube is shown on the right side.

  In the second form shown in FIG. 7B, the elongated hole of the small-diameter cylindrical portion 1b has an enlarged diameter in a region facing the thick portion 1b1. As a result, the capillary is enlarged.

  In the third embodiment shown in FIG. 7 (c), the diameter of the elongated hole of the small diameter cylindrical portion 1b is enlarged in the region facing the thin portion 1b2. Thereby, the quantity with which the sealing part of the sealing material 4 is filled increases.

The schematic front view which shows the 1st form for implementing the high pressure discharge lamp of this invention Similarly, enlarged cross-sectional front view of arc tube The graph which shows the erosion rate evaluation by the acceleration test of the high pressure discharge lamp in the 1st form of this invention with that of a comparative example The principal part sectional drawing of this invention (1st form), the comparative example 1 and the comparative example 2 is shown, (a) is this invention, (b) is the comparative example 2 , (c) is the comparative example 1. The graph which shows the temperature distribution of each part of the translucent ceramics discharge vessel in the 1st form of this invention with that of a comparative example Sectional drawing of the principal part for demonstrating the relationship between the outer surface shape of the boundary part of the thick part of a small diameter cylinder part in the 1st form of this invention, and a thin part, and a defect rate Another embodiment for carrying out the high-pressure discharge lamp of the present invention is shown in comparison with the first embodiment. FIG. 7 (a) shows the first embodiment, FIG. 7 (b) shows the second embodiment, and FIG. C) is a sectional view of the main part of the arc tube of the third embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Translucent ceramic discharge vessel, 1a ... Enveloping part, 1b ... Small diameter cylinder part, 1b1 ... Thick part, 1b2 ... Thin part, 1c ... Discharge space, 2 ... Electrode, 2a ... Electrode axis, 2a1 ... Projection part, 2b ... Electrode coil, 2c ... Electrode shaft coil, 3 ... Power feeding member, 3a ... Sealing conductive member, 3b ... Halogen resistant conductive member, 4 ... Sealing material, IT ... Arc tube

Claims (5)

A surrounding portion that surrounds the discharge space and a small-diameter cylindrical portion that is disposed at both ends of the surrounding portion and has a smaller inner diameter than the surrounding portion, the surrounding portion and the small-diameter cylindrical portion are integrally molded and sintered, and the small-diameter cylinder Translucent ceramic discharge vessel in which the portion has at least two types of thickness and has a relatively thick wall portion in a region having a substantial length continuous with the surrounding portion When;
A pair of electrodes, the proximal end of which is inserted into the small-diameter cylindrical portion while forming a slight gap between the inner surface of the small-diameter cylindrical portion of the translucent ceramic discharge vessel, and the distal end faces the discharge space;
A power supply member having a distal end portion inserted into the small diameter cylindrical portion and connected to the proximal end of the electrode, and the proximal end portion exposed to the outside from the small diameter cylindrical portion;
A sealing material that enters between the power supply member and the small-diameter cylindrical portion to hermetically seal the translucent ceramic discharge vessel;
A discharge medium enclosed in a ceramic discharge vessel;
And a connecting portion between the electrode and the power supply member is opposed to a thick portion of the small-diameter cylindrical portion that is continuous with the surrounding portion . The power supply member has a sealing conductive member whose proximal end is exposed to the outside of the small-diameter cylindrical portion and whose distal end is inserted into the small-diameter cylindrical portion and a proximal end connected to the distal end of the sealing conductive member, and the distal end of the electrode is an electrode. A halogen-resistant conductive member connected to the base end is provided, and a connection portion formed on the halogen-resistant conductive member of the electrode and the power feeding member is opposed to a thick portion continuous with the surrounding portion. 1 Symbol mounting the high-pressure discharge lamps. The high-pressure discharge lamp according to claim 1 or 2 , wherein the electrode has a diameter at a base end smaller than a diameter of a portion adjacent to the base end of the electrode of the power supply member. The translucent ceramic discharge vessel has a continuous curved surface connecting the thick part in the region on the side continuous with the surrounding part of the small-diameter cylindrical part and the relatively thin part adjacent thereto. The high-pressure discharge lamp according to any one of claims 1 to 3 . The high-pressure discharge lamp according to any one of claims 1 to 4 , wherein the discharge medium contains at least one kind of halide of sodium (Na) and thallium (Tl) and a halide of rare earth metal.

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