JP2010123489A - High-pressure discharge lamp and lighting fixture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure discharge lamp with diffusion property and total luminous flux improved by being equipped with a light diffusion film in which a diffusion material having a specific structure is electrostatic-coated, and provide a lighting fixture equipped with the lamp. <P>SOLUTION: The high-pressure discharge lamp includes a translucent airtight vessel 1, at least one pair of electrodes 2, 2 arranged in the translucent airtight vessel, an arc tube IT having an ionized medium enclosed inside the translucent airtight vessel, an outer tube OT which surrounds the arc tube and the inside of which is kept vacuum against the atmosphere or which encloses inert gas atmosphere, and a light diffusion film LD formed by being coated with hollow metal oxide particulates on the inside face of the outer tube without including a binding material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a high-pressure discharge lamp including a light diffusing film and a lighting fixture including the same.

  A high-pressure discharge lamp in which a light diffusion type light distribution characteristic is provided by providing a light diffusion film in a high-pressure sodium lamp, a metal halide lamp, or the like is known (for example, see Patent Document 1). The high-pressure discharge lamp described in Patent Document 1 is composed of 90% calcium pyrophosphate and 10% silicon dioxide, and is electrostatically coated on the inner surface of the outer tube.

  In addition, in a high-pressure discharge lamp whose arc tube is made of quartz glass, it has a light diffusion film using a specific phosphor, so that it has a total luminous flux that is substantially the same or further improved as a transparent type, or a correlated color temperature that is almost equivalent. A high-pressure discharge lamp is also known (for example, see Patent Document 2).

Japanese translation of PCT publication No. 2003-5362216 Special table 2003-297284 gazette

  However, the light diffusion films used in this type of conventional high-pressure discharge lamp all have low luminous efficiency when the diffusivity is improved, and a high-pressure discharge lamp with both good light diffusivity and total luminous flux is obtained. It was difficult to get.

  An object of the present invention is to provide a high-pressure discharge lamp having a good diffusibility and total luminous flux by providing a light diffusing film using a light diffusing material having a specific structure, and a lighting fixture including the same. .

  A high-pressure discharge lamp according to the present invention includes a translucent airtight container, an arc tube including at least a pair of electrodes disposed inside the translucent airtight container, and an ionization medium sealed inside the translucent airtight container; An outer tube that surrounds the tube and is maintained in a vacuum or inert gas atmosphere with respect to the outside air; and the inner surface of the outer tube is coated with metal oxide fine particles having a hollow interior without containing a binder. And a light diffusion film formed by the method.

  The present invention allows the following aspects.

  The translucent airtight container is allowed to be made of translucent ceramics or quartz glass. However, since the translucent ceramic has a high heat-resistant temperature, a translucent airtight container using the translucent ceramic can increase the operating temperature. It is easy to improve the color balance and luminous efficiency of the discharge lamp. For this reason, in this invention, a light-diffusion film functions more effectively and it becomes easy to obtain the outstanding light diffusibility and a high total light beam simultaneously.

  Translucent ceramics include translucent alumina, yttrium-aluminum-garnet (YAG), yttrium oxide (YOX), and polycrystalline non-oxides such as polycrystalline or single crystal such as aluminum nitride (AlN). Ceramics or the like can be used. If necessary, it is allowed to form a halogen-resistant or metal-resistant transparent coating on the inner surface of the hermetic container or to modify the inner surface of the translucent ceramic hermetic container.

  The electrodes are at least a pair in order to cause the main discharge to occur inside the translucent airtight container. For example, an auxiliary electrode is provided on one end side or both end sides of the translucent airtight container to assist in starting. Is acceptable.

  In the present invention, the ionization medium includes a metal halide of a luminescent metal, a starting gas and a lamp voltage forming medium, such as mercury or a metal halide having a low vapor pressure and relatively low visible light emission, or sodium, starting An embodiment containing gas and mercury is preferred. Therefore, the present invention is particularly effective when the high-pressure discharge lamp is a metal halide lamp or a high-pressure sodium lamp. However, in the present invention, the ionization medium is not limited to this.

  In the case of a metal halide lamp, mercury can be used as the lamp voltage forming medium. However, if a metal halide having a low vapor pressure and relatively little visible light emission is used as the lamp voltage forming medium, a mercury-free metal halide lamp can be obtained. It is done. Examples of the lamp voltage forming medium in this case include magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), zinc (Zn), nickel (Ni), manganese (Mn), and aluminum (Al). , One or more selected from the group consisting of antimony (Sb), beryllium (Be), rhenium (Re), gallium (Ga), titanium (Ti), zirconium (Zr) and hafnium (Hf) Halides can be used.

  In the metal halide lamp, various known metals can be used as the light emitting metal of the ionization medium. For example, one or more selected from the group of rare earth metals, scandium (Sc), and sodium (Na) can be used as the main component. As the rare earth metal, for example, thulium (Tm) and holmium (Ho) are suitable.

  Thulium emits a number of emission line spectra near the peak wavelength of the luminous characteristic curve at the time of discharge, and the emission peak coincides with the peak of the luminous efficiency curve, which is an extremely effective light emitting metal to improve luminous efficiency. It is. However, these metal halides are mainly metal halides that contribute to light emission, but also have an action of increasing the lamp voltage in a mercury-free manner. For this reason, it is possible to reduce the amount of metal halide enclosed mainly as a buffer material for forming a lamp voltage. As a result, it is possible to avoid the adverse effects (increased color deviation and decreased luminous efficiency) that occur when a relatively excessive amount of metal halide for forming the lamp voltage is enclosed. Holmium also has properties similar to those described above for thulium.

  The outer tube hermetically surrounds the arc tube, and the inside thereof is held in a vacuum or an inert gas atmosphere with respect to the outside air. Then, a light diffusion film described later is formed on the inner surface of the outer tube. For this reason, when the light diffusing film described later is electrostatically coated, if moisture exists as an impurity in the outer tube, the adhesion strength of the light diffusing film is adversely affected. Therefore, the mixing of moisture must be prevented as much as possible.

  The outer tube also functions to maintain the operating temperature of the arc tube in a desired range by hermetically storing the arc tube therein and mechanically protecting them. The outer tube can be made of a material having transparency, airtightness, heat resistance and workability, for example, hard glass.

  Furthermore, in order to hermetically seal the outer tube, either a single-side seal or a double-sided seal can be adopted as desired. Note that “single sealing” refers to a structure in which a sealing portion such as a pinch seal is formed only at one end of the outer tube, and the other end is closed without forming a sealing portion. On the other hand, “both ends sealing” refers to a structure in which sealing portions such as pinch seals are formed at both ends of the outer tube.

  Furthermore, since the shape of the outer tube is not particularly limited, various known shapes such as a valve shape such as a BT shape or a T shape can be appropriately selected and employed.

  In the present invention, the light diffusing film is formed using only metal oxide fine particles having a hollow inside and substantially not including a binder. The method for forming the light diffusion film not including the binder is not particularly limited, but it is effective to use electrostatic coating.

  In the present invention, metal oxide fine particles having a hollow interior are used. That is, voids are formed inside the metal oxide fine particles. The outer shape of the metal oxide fine particles and the inner holes may be concentric, or the center may be shifted. Further, the inside of the pores is allowed to be an inert gas such as air or nitrogen. In any case, when visible light is transmitted through the metal oxide fine particles, the visible light is incident on the metal oxide fine particles from the outside, and the visible light is emitted from the internal holes to the outside of the metal oxide fine particles. Is refracted when incident on the metal oxide at least twice, so that it becomes easy to diffuse and good light diffusibility is obtained.

  Further, since the metal oxide fine particles are hollow inside, the thickness of the metal oxide when visible light is transmitted is small, so that loss due to light absorption during transmission is reduced. As a result, a high total luminous flux can be obtained.

  Furthermore, in the present invention, since the light diffusion film does not substantially contain the binder, the light emitted from the arc tube is not easily transmitted by the binder, so that the light diffusion film loses light due to light absorption. Less, the transmittance of the light diffusion film is maintained at a relatively high value.

  Furthermore, the light diffusion film of the present invention does not contain a binder, but can be attached to the inner surface of the outer tube. For example, if electrostatic coating is used, it can be reliably adhered to the inner surface of the outer tube, and the inner state of the outer tube is kept airtight against the outside air, so that the adhesion state of the light diffusion film can be maintained well over a long period of time. be able to. In addition, since the metal oxide fine particles are hollow and lighter than metal oxide fine particles having a solid interior, the power consumption during electrostatic coating can be reduced. As a result, the manufacturing cost of the light diffusing film can be reduced, and the environmental load at the time of manufacturing the lamp is reduced.

  In the light diffusing film exhibiting the above operations and effects, the metal oxide fine particles have an average particle diameter of 2 μm or more. If the particle size is smaller than this, it becomes difficult to actually obtain the required light diffusion action. The particle diameter of the metal oxide fine particles is preferably an average particle diameter of 10 μm or less. The average particle size is preferably 2.5 to 7 μm. Furthermore, the film thickness of the light diffusion film is preferably set as a function of the average particle diameter of the metal oxide fine particles, and is preferably about 2 to 5 times the average particle diameter. Within this range, a sufficient light diffusion effect and a high total luminous flux can be obtained when the thickness of the light diffusion film is about 5 to 15 μm.

Furthermore, the metal oxide constituting the light diffusion layer can be used in any one or a mixture form of a plurality of types of silicon oxide (SiO ₂₎ and aluminum oxide (Al 2 _{O 3).} In any metal oxide, it is preferable that the fine particles have a hollow inside and a substantially spherical outer shape.

  Furthermore, the position where the light diffusion film is formed on the inner surface of the outer tube is allowed to be the same as in a known high-pressure discharge lamp. That is, the light diffusing film is preferably formed at least within a range in which the main light emission angle of the arc tube with respect to the tube axis is expected with the inner surface of the outer tube facing the main light emitting region on the side surface of the arc tube.

  The luminaire of the present invention comprises: a luminaire main body; a high-pressure discharge lamp according to any one of claims 1 to 3 disposed in the luminaire main body; and a lighting circuit for lighting the high-pressure discharge lamp. It is characterized by being.

  In the present invention, the luminaire is a concept that includes a device that uses the high-pressure discharge lamp of the present invention as a light source, and includes not only an indoor and outdoor luminaire, but also, for example, a marker lamp, an indicator lamp, a photochemical reaction device, and the like. is there. In addition, the luminaire main body refers to all remaining portions excluding the high-pressure discharge lamp and the lighting circuit from the luminaire. The lighting circuit may have an electronic configuration, or may have a configuration mainly including a coil and an iron core.

  According to the present invention, the light diffusion film formed on the inner surface of the outer tube is formed by depositing hollow metal oxide fine particles that do not contain a binder and the inside is high, so that the total luminous flux is high. In addition, it is possible to provide a light diffusing high-pressure discharge lamp capable of obtaining good diffused light and a lighting fixture including the same.

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

  1 and 2 show an embodiment for carrying out the high-pressure discharge lamp of the present invention. FIG. 1 is a sectional front view of a main part, and FIG. 2 is an enlarged sectional view of an arc tube. The high-pressure discharge lamp of this embodiment is a metal halide lamp with a rated lamp power of 250 W that can be adapted to general lighting applications, and includes a luminous tube IT, an outer tube OT, and a light diffusion film LD. In the figure, UVE is an ultraviolet radiation discharge tube, SG is a protective glass tube, SF is an arc tube support member, G1 and G2 are getters, and B is a base.

  As shown in FIG. 2, the arc tube IT includes a translucent airtight container 1, a pair of electrodes 2, 2, a pair of current introduction conductors 3, 3, a pair of sealing materials 4, 4 and an ionization medium.

The translucent airtight container 1 is made of translucent ceramics, for example, translucent polycrystalline alumina ceramics. And it is provided with the surrounding part 1a and a pair of small diameter cylindrical parts 1b and 1b, and has comprised the integrally molded structure. The surrounding portion 1a has a bowl shape, and includes an intermediate cylindrical portion and a pair of hemispherical portions continuous at both ends thereof, and a discharge space 1c is formed therein. The small-diameter cylindrical portion 1b has an elongated pipe shape, and the tip communicates with the central portion of the hemispherical portion of the surrounding portion 1a.
The electrode 2 includes a shaft portion 2a, an electrode coil 2b, and an electrode mount subcoil 2c. The shaft portion 2a is made of doped tungsten, and is elongated and has a distal end facing the inside of the surrounding portion 1a of the translucent ceramic hermetic container 1, a proximal end is butt welded to the distal end of the current introduction conductor 3, and an intermediate portion is a small diameter cylinder. The inside of the shaped part 1b is inserted. The electrode coil 2b is mounted by being wound around the tip end side of the rod-shaped body 2a. The electrode mount subcoil 2c is formed by winding a thin wire such as tungsten across the shaft portion 2a and the distal end side of a current introduction conductor 3 to be described later, and has an outer peripheral surface and an inner surface of the small diameter cylindrical portion 1b. A slight gap called a capillary is formed between them.

  The current introduction conductor 3 includes a sealing portion 3a and a halogen-resistant portion 3b connected in series. The sealing portion 3a is made of a rod-shaped body of niobium (Nb), seals the light-transmitting airtight container 1 in cooperation with a sealing material 4 described later, and has a base end that is light-transmitting airtight container. 1 is exposed to the outside. The halogen-resistant portion 3b is made of a molybdenum rod-like body, and its base end is butt welded to the tip of the sealing portion 3a and inserted into the small-diameter cylindrical portion 1b of the translucent airtight container 1. Further, the base end of the shaft portion 2a of the electrode 2 is welded to the tip portion.

  The sealing material 4 is made of a frit glass, that is, a melted and solidified body of a ceramic compound, and enters the small-diameter cylindrical portion 1b, and the sealing portion 3a and the small-diameter cylinder of the current introduction conductor 3 positioned in the small-diameter cylindrical portion 1b. The sealing portion 3a and the small-diameter cylindrical portion 1b are hermetically sealed by filling a gap between the inner surface of the transparent portion 1b and the surface of the sealing portion 3a is the same as that of the translucent airtight container 1. The base end portion of the halogen resistant portion 3b is also surrounded so as not to be exposed inside the small diameter cylindrical portion 1b.

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

  The metal halide includes at least a metal halide that mainly contributes to light emission. In this embodiment, at least one halide of a rare earth metal such as thulium (Tm) and holmium (Ho) is enclosed as a metal halide mainly contributing to light emission. In addition to the above, when encapsulating thallium (Tl), if the inner volume of the translucent airtight container 1 is regulated to less than 0.8 mg / cc, the blue light emission suppression phenomenon can be effectively reduced. Can do. Further, in the present embodiment, the metal halide for forming the lamp voltage is mainly included, but mercury is not included.

  As the rare gas, for example, a xenon-based rare gas of 1 to 5 atm is sealed when the ambient temperature is 25 ° C.

  The outer tube OT is made of hard glass. The arc tube IT, the ultraviolet enhancer UVE as a starting auxiliary means, the protective glass tube SG, the arc tube support member SF and the getter G are housed in predetermined positions, and the inside is evacuated. Further, the outer tube OT is provided with a flare stem 5 sealed at a neck portion located at the lower portion in the drawing. The flare stem 5 is provided with a pair of internal lead-in wires 6a and 6b protruding in an airtight manner into the outer tube OT.

  The arc tube IT is disposed at a substantially central portion of the outer tube OT along the central axis inside the outer tube OT, and the current-introducing conductor 3 on the top side is welded to the connection piece 8 and will be described later. It is connected to the internal lead-in wire 6a via the arc tube support member SF. The connection piece 8 has a base end welded to a support frame 9 to be described later, and a tip end welded to the current-introducing conductor 3 on the top side. The arc tube IT has a base-side current introduction conductor 3 welded to the connection conductor 7 and connected to the internal introduction line 6 b via the connection conductor 7.

  The light diffusion film LD is formed by electrostatic coating on the inner surface of the intermediate portion in the tube axis direction of the outer tube OB. That is, the light diffusing film LD is formed by applying a metal oxide fine particle having a hollow inside, for example, a number of hollow fine particles made of silicon oxide, to the inner surface of the outer tube OT by static electricity. Essentially not contained. Since the binder is a non-translucent material, the light diffusing film LD of this embodiment that does not contain the binder has a high total transmittance. The light diffusion film LD is formed on the inner surface of the remaining portion excluding the top portion and the neck portion of the outer tube OT. Then, the visible light emitted from the arc tube IT is diffused and led out of the outer tube OT.

  In the ultraviolet enhancer UVE, the tip of one conductor l1 is sealed in a small and ultraviolet transmissive envelope to form an internal electrode. One conductor l1 is welded to the connection conductor 7 on the base side in FIG. 1 of the arc tube IT. The other conductor l2 that holds the mesh-shaped external electrode in close contact with the outer peripheral surface of the ultraviolet light transmissive envelope is welded to the arc tube support member SF via the connection piece 10 base side. Therefore, the ultraviolet enhancer UVE is connected in parallel to the arc tube IT. A UV-radiating rare gas or the like is enclosed in a UV-transmitting envelope at a low pressure.

  Then, when a high starting voltage is applied between the pair of electrodes 2 and 2 prior to the start of the high pressure discharge lamp, the ultraviolet enhancer UVE starts glow discharge first, and the generated ultraviolet light is mainly used as the arc tube IT. Irradiate near the electrode below. As a result, electrons are emitted from the electrode 2 or the like by the photoelectric effect, and this acts as initial electrons, which excites the ionization medium in the arc tube IT and makes it easy to start.

  The protective glass tube SG is made of a quartz glass cylinder, and surrounds the arc tube IT in a separated state, thereby suppressing the scattering of fragments when the arc tube IT is ruptured. And it is supported by the arc tube support member SF as will be described later. Further, a metal oxide fiber braided string such as alumina or a stainless wire RL is wound around the outer surface of the protective glass tube SG to reinforce the protective glass tube SG.

  The arc tube support member SF includes a support frame 9, a support arm 10, a pair of support plates, and the like, and supports the arc tube IT and the protective glass tube SG. The support frame 9 has a base end connected to the inner lead-in wire 6 a and a top side supported by the inner surface of the outer tube OB by the support arm 10. The support frame 9 fixes a pair of support plates (not shown), and the pair of support plates sandwiches both ends of the protective glass tube SG.

  The getter G1 is a performance getter supported on the top side of the arc tube support member SF. The getter G2 is an initial getter supported on the base side of the arc tube support member SF.

  The base B is a screw-type base and is attached to the neck portion of the outer tube OT in FIG. 1 and connected to the pair of internal lead-in wires 6a and 6b.

    FIG. 3 is a light distribution curve diagram showing the light distribution characteristics on the reference vertical plane of the high-pressure discharge lamp embodying the present invention together with that of the comparative example. In the figure, curve A is an example of the present invention, curve B is a comparative example 1 having a light diffusion film mainly composed of phosphor particles, and curve C is a clear comparative example 2 having no light diffusion film. is there. In each of the above examples, the remaining portions other than the light diffusion film have the same configuration.

  As can be understood from FIG. 3, according to the present invention, the light distribution characteristic curve is a good light distribution characteristic similar to that of Comparative Example 1, and the total luminous flux is obviously larger than that of Comparative Example 1. I understand. The total luminous flux was 97% in the present invention and 95% in Comparative Example 1 when the clear comparative example 2 was taken as 100%.

  FIG. 4 is a cross-sectional view showing a ceiling-embedded downlight as an embodiment for implementing the lighting fixture of the present invention. In the figure, 11 is a high-pressure discharge lamp, and 12 is a lighting fixture body.

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

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

The front view which shows the 1st form for implementing the high pressure discharge lamp of this invention Similarly, cross-sectional view of arc tube Light distribution curve diagram showing the light distribution characteristics on the reference vertical plane of the high-pressure discharge lamp embodying the present invention superimposed on that of the comparative example Sectional drawing which shows the ceiling embedded downlight as one form for implementing the lighting fixture of this invention

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Translucent airtight container, 1a ... Enveloping part, 1b ... Small diameter cylindrical part, 2 ... Electrode, 3 ... Current introduction conductor, 4 ... Sealing material, 5 ... Stem, B ... Base, IT ... Arc tube, LD ... Light Diffusion film, OT ... Outer tube, SF ... Support frame, SG ... Protective glass, UVE ... UV enhancer

Claims (4)

A translucent airtight container, at least a pair of electrodes disposed inside the translucent airtight container, and an arc tube including an ionization medium sealed inside the translucent airtight container;
An outer tube that surrounds the arc tube and whose interior is maintained in a vacuum or inert gas atmosphere with respect to the outside air;
A light diffusion film formed by depositing metal oxide fine particles having a hollow inside without containing a binder on the inner surface of the outer tube;
A high-pressure discharge lamp comprising:   2. The high-pressure discharge according to claim 1, wherein the light diffusion film has metal oxide fine particles made of at least one of silicon oxide and aluminum oxide, an average particle diameter of 2 μm or more, and an outer shape that is substantially spherical. lamp.   3. The high-pressure discharge lamp according to claim 1, wherein the light diffusion film is formed by electrostatic coating. A lighting fixture body;
A high-pressure discharge lamp according to any one of claims 1 to 3 disposed in a lighting fixture body;
A lighting circuit for lighting the high-pressure discharge lamp;
The lighting fixture characterized by comprising.

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