JP2008243385A - High-pressure discharge lamp and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp wherein etching into the bulb inner wall of a high-pressure discharge lamp can be suppressed, and deposits can be prevented from being produced, and their influences to the illuminance of the lamp and to a lamp life are reduced. <P>SOLUTION: The high-pressure discharge lamp comprises: discharge vessel 1 which is composed of ceramic having a garnet structure as a main component, has a small-diameter cylinder being a sealing part, in which a rare earth metal oxide layer is formed on its internal surface; conductors 23a, 23b in which electrodes 2A, 2B are arranged at the tip side which is inserted into and sealed with the small-diameter cylinder: the electrode 2A, 2B which are arranged in the discharge vessel 1 and also arranged at tips of the conductors 23a, 23b; and a discharge medium sealed into the discharge vessel 1. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention particularly relates to a high-pressure discharge lamp using a halogen gas or the like as an enclosed gas, and an illumination device including the high-pressure discharge lamp.

In recent years, demands for high-efficiency and miniaturization of high-pressure discharge lamps are increasing, and as a result, the temperature at the time of lighting and the internal pressure of the bulb have become much higher than before. From such a trend, ceramic bulbs such as Al ₂ O ₃ that have a higher melting point than quartz glass bulbs and can keep the lighting temperature high have come to be used.

However, in high-pressure discharge lamps, halogen gas is used as the sealing gas, and at high temperatures, halogen gas reacts with ceramics such as Al ₂ O ₃ and the bulb is eroded, affecting illuminance and lamp life. There is. That is, when a halogen gas reacts with Al ₂ O ₃ , an aluminum halide compound is produced, but this compound has a low melting point and evaporates to etch the bulb inner wall. The etched material is transferred to the low temperature portion and deposited. Further, even if YAG (yttrium, aluminum, garnet) is used for the valve, although it is not as _high as Al ₂ O ₃ ceramics, it is considered that the generation of deposits has an effect on the life.

  On the other hand, Patent Document 1 discloses a lamp that suppresses reaction with halogen by forming a thin film made of silicon boron nitride on the inner surface of the bulb. Patent Document 2 describes that a coating containing one or more metals selected from tungsten, molybdenum, and rhenium or an alloy thereof is provided in a portion where a liquid metal halide is accumulated.

Japanese Patent Laid-Open No. 9-147801 JP 2003-132842 A

  However, the thing of the cited reference 1 forms a film | membrane by CVD method, and while film-forming is complicated, there exists a problem that a film-forming apparatus becomes large and equipment cost rises. Moreover, the thing of the cited reference 2 is a structure regarding a part of valve | bulb, and it remains in the effect with respect to the limited site | part.

  The present invention has been made in view of the current situation of the high-pressure discharge lamp as described above, and its purpose is to suppress etching of the inner wall of the bulb even in a high-pressure discharge lamp in which a metal halide compound is enclosed. It is possible to provide a high-pressure discharge lamp that can prevent generation of deposits and has less influence on lamp illuminance and lamp life, and an illumination device using the same.

A high-pressure discharge lamp according to the present invention is composed of a ceramic having a garnet structure as a main component, has a small-diameter cylindrical portion serving as a sealing portion, and has a rare earth metal oxide layer formed on the inner surface; A conductor provided with an electrode on the tip side inserted and sealed in the tube portion; an electrode provided in the discharge vessel and provided at the tip of the conductor;
A discharge medium enclosed in the discharge vessel.

  The rare earth oxide is an oxide of a rare earth metal element such as La, Nd, Sm, Gd, Dy, or Ho. It is allowed to contain one or more of these. The range of the rare earth oxide content relative to the ceramic is preferably 0.1 mol% or more and 100 mol% or less. It is also possible to replace the rare earth oxide on the entire inner surface of the discharge vessel.

  The high-pressure discharge lamp according to the present invention is characterized in that the thickness of the layer substituted by the rare earth oxide is 1/10 or less of the maximum wall thickness of the discharge vessel.

  The high-pressure discharge lamp according to the present invention includes a discharge vessel composed of ceramics having a garnet structure mixed with 0.1 to 100 mol% of a rare earth oxide; an electrode on the tip side inserted and sealed in a small diameter cylindrical portion A conductor provided in the discharge vessel and provided at the tip of the conductor; and a discharge medium sealed in the discharge vessel.

  An illuminating device according to the present invention comprises: the high-pressure discharge lamp according to any one of claims 1 to 3; an illuminating device body that holds the high-pressure discharge lamp; and a lighting circuit that lights the high-pressure discharge lamp. It is characterized by that.

  In the high-pressure discharge lamp according to the present invention, a layer in which the inner surface of a discharge vessel made of ceramic having a garnet structure is replaced with a rare earth oxide is formed, so that a rare earth oxide having a high melting point exists on the inner surface of the discharge vessel and is enclosed. Therefore, it is difficult to cause etching due to the halide, and it is possible to suppress the change in mechanical strength and the influence on the lifetime, and the effect that the change in illuminance due to the etched deposit is less likely to occur.

  In the high-pressure discharge lamp according to the present invention, the inner wall portion of the discharge vessel is mainly composed of rare earth oxide, so that the influence on the inner wall of the discharge vessel can be suppressed. Further, since the thickness of the rare earth oxide layer is set to 1/10 or less of the entire thickness of the discharge vessel, the thickness of the rare earth oxide layer is not unnecessarily increased, and the discharge vessel base material has a garnet structure. It can be composed of ceramics.

  The high-pressure discharge lamp according to the present invention is composed of ceramics having a garnet structure mixed with 0.1 to 100 mol% of rare earth oxide, suppresses the generation of aluminum halide compounds, and is suitable for lamp illuminance and lamp life. It is possible to reduce the influence.

  Since the lighting device according to the present invention includes the high-pressure discharge lamp according to any one of claims 1 to 3, it is difficult to cause etching by the enclosed halide, and the mechanical strength is changed and the life is shortened. The effect of reducing the illuminance is less likely to occur due to the etched deposit.

  Embodiments of a high-pressure discharge lamp and a lighting device using the same according to the present invention will be described below with reference to the accompanying drawings. In each figure, the same components are denoted by the same reference numerals, and redundant description is omitted. The high-pressure discharge lamp according to this example has the configuration shown in FIGS. The high-pressure discharge lamp shown in these drawings has a structure suitable for a rated lamp power of 100 W. As shown in FIG. 1, the arc tube 1A, the outer tube 5, the UV enhancer 7, the shroud glass 3, and the support structures 4A and 4B. And a base 6.

  The arc tube 1A shown in FIG. 2 will be described. The arc tube 1 </ b> A includes a discharge vessel 1, electrodes 2 </ b> A and 2 </ b> B, a pair of conductors 23 a and 23 b, a pair of frit glasses 13 and 13, and a discharge medium sealed inside the discharge vessel 1.

  The discharge vessel 1 is composed mainly of ceramics having a garnet structure. The surrounding part 11 and a pair of small diameter cylinder parts 12a and 12b disposed in communication with both ends of the surrounding part 11 are provided. And the small diameter cylinder parts 12a and 12b and the surrounding part 11 are integrated by casting.

  The surrounding portion 11 has a substantially bowl shape formed by connecting two hemispheres in a straight line between the hemispherical portions in a state of being axially spaced so as to face each other. Is 0.5 to 2.0 mm, and 0.8 mm in this embodiment.

  The pair of small-diameter cylindrical portions 12a and 12b each have a pipe shape with an inner diameter of about 1 mm, and the tip is connected to the central portion of the hemispherical portion of the surrounding portion 11 corresponding thereto. In addition, as for the boundary part of the envelopment part 11 and the small diameter cylinder parts 12a and 12b, the inner and outer both surfaces are formed by the curved surface.

  Each of the electrodes 2A and 2B includes an elongated shaft portion 21 and an electrode main portion 22 each made of a tungsten rod having an outer diameter of 0.5 mm. The elongated shaft portion 21 is inserted into the small-diameter cylindrical portions 12a and 12b, and a coil portion 24 and 24 is formed around the tungsten thin wire. A slight gap is formed between the elongated shaft portion 21 and the inner surfaces of the small diameter cylindrical portions 12a and 12b. The electrode main portion 22 is formed by winding a tungsten thin wire having an outer diameter of 0.1 mm for five turns around the distal end portion of the elongated shaft portion 21 and projects into the surrounding portion 11.

  Each of the pair of conductors 23a and 23b includes a niobium rod-shaped body Nb and a cermet SM as a sealing conductor existing on the electrode main portion 22 side. The niobium rod-shaped body Nb and the cermet SM are linearly welded. It is integrally formed. The niobium rod-like body Nb has a distal end inserted into the small diameter cylindrical portions 12a and 12b and a base end protruding outside from the small diameter cylindrical portions 12a and 12b. The rod-like cermet SM has an outer diameter of 0.6 mm and is made of a sintered body of molybdenum-alumina ceramics. The base ends of the elongated shaft portions 21 of the electrodes 2A and 2B are integrally connected to the tips by welding or the like. Yes.

The high-pressure discharge lamp of the present invention is sealed with a frit glass 13. An electrode mount composed of the electrode main portion 22, the cermet SM, and the conductor 23a is inserted from the opening of the small diameter cylindrical portion 12a to a predetermined position. In the electrode mount, stoppers are formed at predetermined positions of the conductors 23a and 23b. For this reason, the position where the stopper is in contact with the end surface of the small-diameter cylindrical portion 12a is the predetermined insertion position.

Next, a frit glass molded body molded in a ring shape in advance from above the conductor 23a of the electrode mount is inserted and placed on the end surface of the small diameter cylindrical portion 12a extending upward. Here, for example, a laser beam such as a laser beam is irradiated from the axial direction of the small-diameter cylindrical portion 12a to heat the planned sealing portion including the frit glass molded body. When the frit glass molded body is melted, a part of the frit glass 13 enters the inside from the end face of the small-diameter cylindrical portion 12a, surrounds the insertion portion of the conductor 23a, and seals the discharge vessel 1. Thereafter, when cooled, a seal on one end side of the arc tube 1A is formed. The other end side related to the small diameter cylindrical portion 12b is similarly sealed.

  The discharge medium is made of argon (Ar) as a starting gas and a buffer gas, the following metal halide, and mercury as a buffer vapor, and is enclosed in a translucent ceramic discharge vessel 1. Since metal halide and mercury are encapsulated in excess of the amount that evaporates, some of the metal halide and mercury are contained in the coil portions 24 and 24 in the small gaps formed in the small diameter cylindrical portions 12a and 12b during stable lighting. It stays in a liquid phase in the formed gap. And the coldest part is formed in the surface layer part vicinity of the discharge medium which stays in the liquid phase state in the small diameter cylinder part 12b used as the lower side during lighting, for example.

  The outer tube 5 has a T-shaped bulb shape made of hard glass, and is provided with a flare stem 4s sealed at the neck portion. The flare stem 4s introduces a pair of lead wires 41a and 41b in an airtight manner. The outer tube 5 accommodates and stores the arc tube 1A at a predetermined position inside it by support structures 4A and 4B described later.

  The UV enhancer 7 includes an airtight container, an introduction wire, an internal electrode, a discharge medium, and an external electrode. The hermetic container is made of ultraviolet ray transmissive glass such as quartz glass, and a pinch seal portion is formed at one end thereof, thereby forming a long and narrow discharge space inside. The lead wire is welded to an internal electrode, which will be described later, led out to the outside from the pinch seal portion, and welded to a support frame 42a, which will be described later, at the base end portion as shown in FIG.

  The internal electrode has a plate shape made of molybdenum, is sealed in a discharge space of an airtight container, and a base portion thereof is airtightly embedded in a pinch seal portion. The external electrode is made of a molybdenum wire having an outer diameter of 0.4 mm, is closely wound on the outer periphery of the hermetic container and is wound for five turns, and its base end is welded to the support structure 42b. Thus, the UV enhancer 7 is disposed at a predetermined position in the outer tube 5 by the base end portion of the lead-in line and the base end portion of the external electrode. With the structure described above, the UV enhancer 7 is connected in parallel with the arc tube 1A in the outer tube 5 and is held at a position close to one electrode of the arc tube 1A.

  The shroud glass 3 is made of a cylindrical quartz glass body having a wall thickness of 1.0 mm and can be accommodated in the outer tube 5, and is held by a support member 45a described later at a position surrounding the arc tube 1A in the outer tube 5. Has been.

  The support structure 4A includes a support frame 42a, a bridge conductor 43a, spring pieces 44a and 44a, and a support member 45a. The lower end of the support frame 42a is connected to the lead-in line 41a in FIG. 1, and the upper end is extended to form a spring piece 44a. The bridge conductor 43a supports the upper portion of the arc tube 1A by being welded to the upper conductor 23a in the figure of the arc tube 1A. The spring piece 44 a elastically contacts the inner surface of the outer tube 5 to prevent the upper part of the support frame 42 a from rolling with respect to the inner surface of the outer tube 5. The support member 45 a supports the upper and lower ends of the shroud glass 3.

  The support structure 4B has a straight bar shape, and its lower part is electrically connected to the lead wire 41b sealed to the flare stem 4s to be electrically connected and mechanically supported. The upper end of the arc tube 1A is welded to the lower conductor 23b via a connecting conductor to support the lower portion of the arc tube 1A.

The base 6 is an E39 type base, and is fixed to the neck portion of the outer tube 5. One of a pair of lead wires (not shown) exposed to the outside from the outer tube 5 is connected to the shell portion and the other is connected to the center contact. ing. In FIG. 1, symbol G is a getter, which cleans the inside of the outer tube 5, and is welded to the upper portion of the support frame 42a.

<Example 1>
In this example, the discharge vessel was made of ceramics having a garnet structure, and a coating composed of rare earth oxide Sm ₂ O ₃ fine particles was applied to the inner wall with a thickness of 1.0 to 100 μm to obtain the discharge vessel 1. . The thickness of the discharge vessel 1 was 1 mm on average and the outer diameter was 15 mm. Xe was sealed as the sealing gas, and a ScI ₃ -NaI-based sealing chemical was used.

Here, the discharge vessel of Prototype 1 is made of Al ₂ O ₃ , and the discharge vessel of Prototype 2 is made of YAG that does not contain the rare earth oxide Sm ₂ O _3. The discharge vessel of No. 3 was obtained by applying a paint containing ₃ mol% of rare earth oxide Sm ₂ O ₃ to the inner wall of the discharge vessel made of YAG. The discharge vessel of prototype 4 was made of rare earth oxide Sm ₂ O ₃ . It is applied to the inner wall of a discharge vessel composed of YAG mixed so as to contain 10 mol%.

The prototypes 1 to 4 were continuously lit for 1000 hours, and then the temperature was lowered, and quantitative analysis of the aluminum halide compound on the inner wall was performed using XPS (X-ray photoelectron spectrometer). As a result, as shown in FIG. 3, the relative value with the amount of the aluminum halide compound of the prototype 1 as 100 is 67, the prototype 3 is 31, the prototype 4 is 7, and the rare earth oxide. It has been demonstrated that when a paint containing a large amount of Sm ₂ O ₃ is applied, the generation of an aluminum halide compound can be suppressed, and the influence on the lamp illuminance and lamp life can be reduced.

  From the coating thickness of the prototype, it is considered that a sufficient effect can be obtained even when the film thickness of the rare earth metal oxide is 1/10 or less of the thickness of the entire discharge vessel. In addition, a preferable film thickness range is 10-100 micrometers. Moreover, the range of the amount of the rare earth oxide mixed is effective at 0.1 mol% or more, and since generation of an aluminum halide compound is hardly observed at about several tens mol%, it is 0.1 mol% or more and 100 mol% or less. Is preferred.

  FIG. 9 is a partial cross-sectional front view showing an illumination device 9 according to the present invention in which, for example, the high-pressure discharge lamp L1 is used. This illuminating device 9 is an embedded illuminating device embedded in a ceiling 91, and has an appliance (device) main body 92 attached to the ceiling 91 side, and a socket 93 provided in the appliance (device) main body 92 is attached to a socket 93. The base 6 of the high-pressure discharge lamp L1 is attached. In addition, a reflection mirror 94 that reflects the emitted light of the lamp L1 downward is disposed in the instrument (device) main body 92. The opening side of the reflection mirror 94 is covered with a cover member or a lens made of glass or the like. A light control body 95 is provided.

The high-pressure discharge lamp L1 is electrically connected to an appliance (device) main body 92 or a lighting device having a ballast arranged separately from the main body 92, and is lit by power supplied from the lighting device. Can do.

The lighting device is not limited to the above embodiment, and may have other structures and uses. The lighting method is not limited to the one using the rectangular wave lighting circuit device, and the choke coil type, the transformer type, etc. A magnetic ballast may be used.

The front view which shows the whole lamp | ramp as embodiment of the high pressure discharge lamp in this invention. The expanded sectional view which shows the arc tube as embodiment of the high pressure discharge lamp in this invention. The figure which shows the quantitative analysis result of the aluminum halide compound after performing continuous lighting about the prototype which concerns on the Example in the high pressure discharge lamp in this invention. The conceptual side view of the illuminating device comprised using the high pressure discharge lamp in this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Discharge vessel 2A, 2B Electrode 3 Shroud glass 4A, 4B Support structure 5 Outer tube 6 Base 11 Enclosed part 12a, 12b Small diameter cylindrical part 13 Frit glass 22 Electrode main part 23a, 23b Conductor

Claims (4)

A discharge vessel comprising a ceramic having a garnet structure as a main component, a small-diameter cylindrical portion serving as a sealing portion, and a rare earth metal oxide layer formed on the inner surface;
A conductor provided with an electrode on the tip side inserted and sealed in the small diameter cylindrical portion;
An electrode provided in the discharge vessel and provided at the tip of the conductor;
A discharge medium enclosed in a discharge vessel;
A high-pressure discharge lamp comprising: The high-pressure discharge lamp according to claim 1, wherein the thickness of the layer substituted by the rare earth oxide is 1/10 or less of the maximum thickness of the discharge vessel. A discharge vessel comprising a ceramic having a garnet structure mixed with 0.1 to 100 mol% of a rare earth oxide;
A conductor provided with an electrode on the tip side inserted and sealed in the small diameter cylindrical portion;
An electrode provided in the discharge vessel and provided at the tip of the conductor;
A discharge medium enclosed in a discharge vessel;
A high-pressure discharge lamp comprising: A high-pressure discharge lamp according to any one of claims 1 to 3;
A lighting device main body for holding a high-pressure discharge lamp;
A lighting circuit for lighting the high-pressure discharge lamp;
An illumination device comprising:

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