JP4421172B2 - Metal halide lamp - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to an outer tube that houses an arc tube and a diffusion metal halide lamp that includes a phosphor layer inside the outer tube.
[0002]
[Prior art]
  Metal halide lamps have the characteristics of high lamp efficiency and high color rendering, and are widely used. Metal halide lamps include a transparent type and a diffusion type. In the former, the outer tube containing the arc tube is transparent, and a high light collecting property is obtained when it is used in combination with a reflecting mirror. Since the emitted light is directly in the eyes, it may look very dazzling or uncomfortable. The latter is provided with a phosphor layer on the inner surface of the outer tube, and this phosphor layer acts as a light diffusion film, so that the glare of the metal halide lamp is reduced.
[0003]
  The phosphor layer used in the conventional diffusion metal halide lamp is YPVO.₄: Eu / (SrMg)₃(PO₄2Sn / SiO₂Are mixed at a ratio of 57% / 38% / 5% (both mass%), and the phosphor is excited by ultraviolet rays emitted from the arc tube.16The emission of the spectral distribution shown in FIG.
[0004]
    FIG. 16 is a graph showing a spectral spectrum distribution of a phosphor layer used in a conventional diffusion metal halide lamp. In the figure, the horizontal axis represents wavelength (nm) and the vertical axis represents radiation power (relative value).
[0005]
  As can be understood from the figure, the light emitted from the phosphor layer has main emission peaks at wavelengths of 590 nm, 620 nm, and 700 nm. For this reason, the color rendering properties of the high-pressure discharge lamp are improved.
[0006]
[Problems to be solved by the invention]
  However, in the case of a conventional metal halide lamp, the provision of the phosphor layer lowers the correlated color temperature by about 200 to 400 K and reduces the total luminous flux by about 5 to 10% as shown in FIG. There is a problem.
[0007]
    FIG. 17 is a graph showing the distribution of the relationship between the lamp voltage and the total luminous flux in conventional transparent and diffusive metal halide lamps. In the figure, the horizontal axis represents the lamp voltage (V), and the vertical axis represents the total luminous flux (lm). In addition, the ◯ symbol indicates a transparent type, and the ● symbol indicates a diffusive type, and the other specifications are the same except for the presence or absence of a phosphor layer. The transparent type does not have a phosphor layer, and the diffusion type has the above-described phosphor layer.
[0008]
  As described above, there is a problem that the correlated color temperature and the total luminous flux are different depending on the presence or absence of the phosphor layer. For example, in the same lighting equipment, the transparent type and the diffusing type cannot be used together. Cause inconvenience.
[0009]
  In addition, the conventional metal halide lamp has a large amount of ultraviolet radiation as described below, both in the diffusing type and the transparent type having a phosphor layer. For this reason, there exists a problem that it cannot utilize for the store lighting which dislikes the fading of goods.
[0010]
    FIG. 18 is a graph showing an ultraviolet spectral distribution of wavelengths 280 to 380 nm in the diffusion metal halide lamp shown in FIG. The ultraviolet irradiance of this lamp is 22.3 μW / cm²/ 1000 lx.
[0011]
    FIG. 19 is a graph showing an ultraviolet spectral distribution at a wavelength of 280 to 380 nm in a conventional transparent metal halide lamp. The ultraviolet irradiance of this lamp is 25.3 μW / cm²/ 1000 lx.
[0012]
  Therefore, conventionally, in order to reduce ultraviolet radiation, it has been necessary to use lead glass having a low ultraviolet transmittance for the outer tube.
[0013]
  An object of the present invention is to provide a diffusion-type metal halide lamp in which the total luminous flux is substantially the same or further improved as the transparent type, the correlated color temperature is substantially the same, and the color deviation is small.
[0014]
  Another object of the present invention is to provide a diffusion-type metal halide lamp with a small amount of ultraviolet radiation.
[0015]
[Means for achieving the object]
    The metal halide lamp of the invention of claim 1 is a translucent discharge vessel in which a discharge space is formed, and at least a pair of electrodes sealed in the translucent discharge vessel and present in the discharge space of the translucent discharge vessel , And an arc tube comprising a discharge medium containing at least Na and Sc halides and enclosed in a translucent discharge vessel; an outer tube containing the arc tube; and europium and manganese activated aluminate phosphorConsist ofFirst phosphor and europium-activated yttrium vanadate phosphate phosphorConsist ofThe first phosphor is arranged in the outer tube, and the first phosphor emits blue light (B) with an emission peak wavelength of 440 to 460 nm and green light (G) with 505 to 525 nm. The second phosphor has a red emission (R) with an emission peak wavelength of 585 to 605 nm and is disposed in the outer tube, and a blue emission (B) with an emission peak wavelength of 450 nm. A phosphor layer having a green light emission (G) of 515 nm and a red light emission (R) of 585 to 605 nm, and a radiation power ratio of each color light emission satisfying the following formula: Yes.
[0016]
                B: G: R = 0.5 to 1.1: 1.0 to 1.7: 1.0
  In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified. The metal halide lamp of the present invention comprises at least an arc tube, an outer tube, and a phosphor layer. Hereinafter, each component will be described.
[0017]
  First, the arc tube will be described. The arc tube includes at least a translucent discharge vessel, a pair of electrodes, and a discharge medium.
[0018]
  The translucent discharge vessel is made of quartz glass, and sealing portions are formed at both ends for sealing the electrodes. The sealing portion can employ a sealing structure such as a pinch seal method or a reduced pressure sealing method. Molybdenum foil is embedded inside the sealing portion of the pinch seal structure or the reduced pressure sealing structure, the base end of the electrode shaft is welded to one end of the molybdenum foil, and the lead wire is welded to the other end. .
[0019]
  Further, the translucent discharge vessel allows the surrounding portion surrounding the discharge space to have a desired shape such as a cylindrical shape, a spherical shape, a spheroid shape, or a spindle shape.
[0020]
  Furthermore, the translucent discharge vessel may have any configuration of sealing at both ends and sealing at one end.
[0021]
  At least a pair of electrodes are sealed in a pair of sealing portions at both ends or a single sealing portion at one end of the translucent discharge vessel, and are present inside the translucent discharge vessel. Further, if necessary, an auxiliary electrode can be sealed in the vicinity of one of the pair of electrodes. The structure of the electrode is not particularly limited, but is generally constituted by a shaft of tungsten or doped tungsten and a coil of the same material wound around the tip of the shaft.
[0022]
  The discharge medium must contain at least Na and Sc halides as the luminescent metal. However, if necessary, in addition to the above metals, Cs, Tl, and other rare earth metals such as Dy can be added. The addition of Cs halide suppresses the extinction voltage rise, and as a result, the emission color and the correlated color temperature also slightly change.
[0023]
  Generally, I is used as the halogen, and if necessary, an appropriate amount of Br is added. Further, a rare gas can be enclosed as a starting gas and a buffer gas.
[0024]
  More preferably, mercuryTheIncluded as buffer gasDobe able to.
[0025]
  Next, the outer tube will be described. The outer tube contains the arc tube in an airtight manner, mechanically protects the arc tube, and maintains the operating temperature of the arc tube in a desired range. The inside of the outer tube can be evacuated and filled with vacuum or low pressure or an inert gas such as a rare gas or nitrogen as necessary. The outer tube can be made of a material having appropriate translucency, airtightness, heat resistance and workability, for example, hard glass.
[0026]
  Further, when the outer tube is hermetically sealed, any structure of one-side sealing and both-end sealing 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.
[0027]
  Furthermore, the inside of the outer tube can be evacuated as necessary to enclose vacuum or low pressure or an inert gas such as a rare gas.
[0028]
  Further, the phosphor layer will be described. The phosphor layer only needs to be disposed inside the outer tube. Therefore, for example, a cylindrical tube is disposed between the inner surface of the outer tube or the inner surface of the outer tube and the arc tube, and the wall surface thereof. Can be formed. When the phosphor layer is formed on the inner surface of the outer tube, the phosphor layer may be formed over almost the entire outer tube, or a part of the phosphor layer may be formed, for example, leaving the vicinity of the head and / or neck. .
[0029]
  Next, the phosphor layer includes the first and second phosphors in the following manner and is disposed in the outer tube. The first phosphor is europium and manganese activated aluminate phosphorConsist ofThe second phosphor is a europium-activated yttrium vanadate phosphate phosphor.ByIt is configured.
[0030]
  AlsoWhen the phosphor layer is excited by ultraviolet light having a wavelength of 400 nm or less transmitted through the arc tube, blue light emission (B) having an emission peak wavelength of 440 to 460 nm, green light emission (G) having 505 to 525 nm, and Light emission having a red light emission (R) of 585 to 605 nm and a peak ratio of the radiant power of each color light emission is within a predetermined range.The blue light emission (B) having an emission peak wavelength of 440 to 460 nm and the green light emission (G) having a light emission peak wavelength of 505 to 525 nm are light emission of the first phosphor. Red light emission (R) having an emission peak wavelength of 585 to 605 nm is light emission of the second phosphor.In addition, each color light emission and the subsequent codes (B), (G), and (R) are notations used for convenience to distinguish and divide the color light into three, and therefore, the color light.TheIt does not mean exactly. And even if it is in said wavelength range, colored light changes according to the wavelength.
[0031]
  Further, the peak ratio of the radiant power of each color emission is 0.5 to 1.1 for B and 1 to 1.0 for G in the emission spectrum distribution of the phosphor layer, where R is 1. 7. A first phosphor that emits blue-green light having emission peaks at wavelengths of 440 to 460 nm and 505 to 525 nm, and a second phosphor that generates red light emission having emission peaks at wavelengths of 585 to 605 nm, By using the phosphor layer at a ratio of 1: 1 to 2: 1, the peak ratio of the radiant power can be easily obtained. In this case, it may be a single phosphor layer in which the first and second phosphors are mixed, a phosphor layer made of the first phosphor, and a phosphor layer made of the second phosphor. The structure which piled up may be sufficient.
[0032]
  In addition, in order to measure the peak ratio of the radiant power of each emission color of the phosphor, the following method is used. That is, the phosphor powder to be measured is placed in a heat-resistant data base having a shallow concave portion, and the ambient temperature is heated to 230 ° C. in the atmosphere, which is equivalent to the temperature of the phosphor layer arrangement position of the metal halide lamp. Mercury lamp (rated UV intensity at room temperature 4400μW / cm²), Ultraviolet rays having wavelengths of 254, 312 and 365 nm are extracted by an optical filter that cuts wavelengths of 400 nm or more from the emitted light, and the phosphor is irradiated. Then, the spectrum of the fluorescence generated from the phosphor is measured with an instantaneous spectrometer. As a result, the peak ratio of the radiant power of each color emission is determined from the obtained spectral distribution curve. In addition, visible light generated from the first and second phosphors is allowed to be generated not only in the above wavelength range but also outside the above wavelength range. . The main peak may exist outside the above wavelength range, and a sub-peak may be generated within the above wavelength range.
[0033]
  The typical chemical formula of each phosphor is as follows.
[0034]
  1  First phosphor:
(1) Europium and manganese activated aluminate phosphor
  General formula: a (M1) O · bAl ₂ O ₃ : Eu, Mn
  However, in formula, M1 shows at least 1 type selected from the group of Mg, Ca, Sr, Ba, Zn, Li, Rb, and Cs. a and b are numbers satisfying a> 0, b> 0, and 0.2 ≦ a / b ≦ 1.5.
[0035]
  2  Second phosphor
(1) Europium-activated yttrium vanadate phosphate phosphor
  General formula; YPVO ₄ : Eu
  3  Chromaticity
The first phosphor and the second phosphor have a mass of 1: 1 to 2 so that the chromaticity coordinates of the phosphor alone are x0.29 to 0.36 and y0.29 to 0.31. The compounding ratio is adjusted in the range of: 1.
[0036]
  In the present invention, a preferred combination of the first and second phosphors is that the first phosphor is BaMgAl. ₁₀ O ₁₇ : Eu and (Ba, Mg) O.6Al ₂ O ₃ : Eu, Mn and the second phosphor is YPVO ₄ : Eu. The preferred blending ratio of the first phosphor is BaMgAl ₁₀ O ₁₇ : Eu / (Ba, Mg) O.6Al ₂ O ₃ : Eu, Mn = 1 / 1.5 (mass ratio). Moreover, the suitable compounding ratio of the 1st and 2nd fluorescent substance is the range of (1st fluorescent substance) / (2nd fluorescent substance) = 1/1-2/1 (mass ratio).
[0037]
  Furthermore, in addition to the phosphor, fine particles such as a metal oxide such as silicon dioxide are allowed to be contained in the phosphor layer. In this case, the average particle diameter of the metal oxide fine particles is preferably an order of magnitude smaller than the average particle diameter of the phosphor particles by one digit or more, for example, about 0.3 μm so as to adhere around the phosphor particles. Thereby, a fluorescent substance layer becomes easy to adhere stably.
[0038]
  Other configurations will be described. In addition to the configuration described above, the following configurations can be selectively added as necessary.
  1. About the configuration adapted to an inexpensive ballast
  Inexpensive ballasts are generally small and have a low secondary voltage, as found in mercury lamp ballasts. Further, in order to configure a high pressure discharge lamp so as to be compatible with an inexpensive ballast, it is necessary to increase the lamp power factor to some extent. This is necessary in order to overcome a ballast that does not increase the secondary voltage too much, and there is a concern of arc extinction during the lifetime. In the present invention, as described above, since the light emitting metal of the ionization medium uses Sc and Na as main components, the lamp power factor can be increased, and it is suitable for a small ballast such as a mercury lamp ballast. The high pressure discharge lamp can be easily realized.
  About 2 pulse starters
  A pulse starter can be built in the outer tube. The pulse starter is mainly composed of a glow starter and is connected in parallel to the arc tube. In a metal halide lamp type high-pressure discharge lamp, impurities such as H 2 O that hinder discharge are easily mixed when a halide of a light-emitting metal is sealed. For this reason, it is hard to start compared with a mercury lamp. Therefore, by incorporating a pulse starter, the high pressure discharge lamp can be easily started.
[0039]
  Finally, the operation of the present invention will be described. In the present invention, since the phosphor layer having a predetermined configuration is provided, visible light emitted from the arc tube is diffused when passing through the phosphor layer, so that the metal halide lamp is configured in a diffusing shape. The
[0040]
  Further, when ultraviolet rays generated by discharge in the arc tube pass through the arc tube and irradiate the phosphor layer, the phosphor is excited and emits visible light. Ultraviolet rays are included during light emission from the light emitting metal Sc. Further, when mercury is enclosed as a buffer gas, an ultraviolet emission line is generated by discharge.
[0041]
  Europium and manganese activated aluminate phosphorsConsist ofFirst phosphor and europium-activated yttrium vanadate phosphate phosphorConsist ofThe light emitted from the phosphor layer including the second phosphor has emission peaks at wavelengths of 440 to 460 nm, 505 to 525 nm, and 585 to 605 nm, and the peak ratio of the radiation power is the same as that described above. By being within the predetermined range, the total luminous flux of the high-pressure discharge lamp is substantially the same as that in the transparent type not including the phosphor layer, or more, for example, several percent improvement.
[0042]
  Furthermore, the color temperature is almost unchanged compared to that in the transparent form.
[0043]
  Furthermore, since the phosphor layer having a predetermined configuration is provided, the chromaticity of light emission is closer to that of a black body than that of a transparent type not provided with the phosphor layer. For this reason, white light is obtained. However, the chromaticity deviation isTransparent typeMuch more than that insmall.
[0044]
  Furthermore, since most of the ultraviolet rays transmitted through the arc tube and emitted into the outer tube are efficiently converted into visible light by irradiating the phosphor layer in the outer tube, the ultraviolet rays transmitted through the outer tube and emitted to the outside. The amount is significantly reduced. As a result, the irradiance of ultraviolet light having a wavelength of 380 nm or less is 10 μW / cm, which is half or less of that of the prior art.²/ 1000 lx or less. For this reason, even if it is a case where the metal halide lamp of this invention is used for shop lighting, for example, the problem of fading of goods decreases.
[0045]
  On the other hand, conventionally, in order to prevent fading, it has been necessary to use glass that suppresses ultraviolet light transmission, such as lead glass, for the outer tube. However, lead glass has a problem because it contains lead with a large environmental load.
[0046]
    A metal halide lamp according to a second aspect of the present invention is the high pressure discharge lamp according to the first aspect, wherein the arc tube has a lamp power of 500 W or less and a tube wall load of 16 to 30 W / cm.²It is characterized by being.
[0047]
  In the present invention, when the lamp power is 500 W or less, the lamp wall load is in the above range, so that the lamp efficiency and color rendering are improved without affecting the life characteristics, and the discharge medium discharges ultraviolet rays. Radiation increases. For this reason, the phosphor layer is actively excited, the amount of visible light generated from the phosphor layer is increased, and the total luminous flux of the high-pressure discharge lamp is improved. The tube wall load is preferably 17.5 to 22.5 W / cm.²It is.
[0048]
  When the tube wall load is in the above range, a metal halide lamp with a small chromaticity difference can be obtained.
[0049]
  When the lamp power is in the range of over 500 W to 1000 W, the tube wall load is 7 to 20 W / cm.²Can be. If the tube wall load is in this range, the luminous efficiency of the ultraviolet rays radiated into the arc tube will be high. Therefore, even if the tube wall load is reasonably small, the luminous efficiency of visible light similar to the above case can be obtained. In addition, a metal halide lamp with a small chromaticity difference can be obtained. The tube wall load is preferably 9 to 16 W / cm.²It is.
[0050]
    A metal halide lamp according to a third aspect of the present invention is the metal halide lamp according to the first or second aspect, wherein the phosphor layer is disposed on the inner surface of the outer tube, and the outer tube is linearly transmitted at the position where the phosphor layer is disposed. The rate is 55 to 70% when the linear transmittance before arranging the phosphor layer is 100%.
[0051]
  In the present invention, since the linear transmittance of the outer tube at the site where the phosphor layer is formed is within the above range, the change in color temperature and chromaticity is small compared to a transparent metal halide lamp. The linear transmittance is preferably 60 to 65%.
[0052]
  In the present invention, the linear transmittance is measured by the following measuring instrument and measurement procedure.
1. Measuring equipment
(1) Measurement light source: A12-16V12CP shaped bean bulb (manufactured by Toshiba Lighting & Technology Corp.)
(2) Measuring instrument: SPI-5 type rechargeable illuminometer (manufactured by Toshiba Corporation)
(3) Optical slit: a slit with a circular opening having a diameter of 5 mm
(4) Stabilized power supply or voltage regulator for lamp voltage adjustment
(5) Variable resistor for adjusting lamp current
(6) Dark box: The outer tube, the measurement light source, the optical slit, and the light receiver of the measuring device are set in a predetermined relationship and measured in a dark box.
2. Measurement procedure
(1) Setting of measurement light source, measuring instrument and optical slit: Inserting measurement light source and optical slit inside the outer tube to irradiate the portion of the bulb wall surface where the measurement light is directly facing the arc tube of the outer tube The light receiver of the measuring instrument is brought into close contact with the outer surface of the part of the outer tube.
(2) Transmittance measurement of a comparative transparent outer tube: A transparent outer tube having the same specifications as the outer tube to be measured is prepared as a comparative outer tube except that no phosphor layer is provided. Is measured in advance. During measurement, the stabilized power supply or voltage regulator is adjusted to set the voltage applied to the measurement light source to the rated voltage. Further, the lamp current adjusting variable resistor is adjusted to set the lamp current of the measurement light source so that the linear transmittance of the comparative transparent outer tube becomes 100%.
(3) Measurement of linear transmittance of outer tube for measurement: Next, the outer tube for measurement in which the phosphor layer is disposed is measured. As a result, the obtained linear transmittance is the value of the outer tube for measurement.
[0053]
    Claim4The metal halide lamp according to the present invention is any one of claims 1 to3In the metal halide lamp according to any one of the above, the phosphor layer is characterized in that the phosphor has an average particle diameter of 5 μm or less.
[0054]
  In the present invention, by defining the average particle size of the phosphor as described above, the total luminous flux becomes larger than when the average particle size exceeds 5 μm. In addition, an average particle diameter shall be based on BET method.
[0055]
    A metal halide lamp according to a fifth aspect of the present invention is the metal halide lamp according to any one of the first to fourth aspects, wherein the phosphor layer comprises 5 to 15% by mass of silicon dioxide SiO2. ₂ It is characterized by containing.
[0056]
  The present invention relates to silicon dioxide SiO added to the phosphor layer.₂By defining the content ratio of as described above, a required binding force is imparted to the phosphor layer. Silicon dioxide SiO₂When the content ratio is less than 5% by mass, it is difficult to obtain a required binding force. On the other hand, if it exceeds 15 mass%, the reduction of the total luminous flux tends to exceed the allowable range. Silicon dioxide SiO of the present invention₂The above-mentioned content ratio is larger than that in the conventional metal halide lamp of this type, but it has been found that it is in an appropriate general range for the metal halide lamp defined in claims 1 to 5. However, silicon dioxide SiO₂If the content ratio is in the range of 8 to 12% by mass, both a sufficient binding force and a high total luminous flux can be obtained, which is more effective.
[0057]
  Silicon dioxide SiO₂Are preferably fine particles having an average particle size in the range of about 0.1 to 0.6 μm. Furthermore, silicon dioxide SiO as colloidal silica₂The phosphor is preferably added to the phosphor layer by mixing the phosphor with a phosphor to prepare a phosphor coating solution, and coating, drying and firing the phosphor coating solution on the inner surface of the outer tube.
[0058]
  Thus, according to the present invention, it is possible to obtain a diffusion type metal halide lamp having a phosphor layer having a required binding force and not easily peeled off.
DETAILED DESCRIPTION OF THE INVENTION
  Embodiments of the present invention will be described below with reference to the drawings.
[0059]
    FIG. 1 is a front view showing an embodiment of a metal halide lamp of the present invention.
[0060]
    FIG. 2 is a front view showing a state where the phosphor layer is similarly removed.
[0061]
  In each figure, the metal halide lamp MHL includes an arc tube 1, an outer tube 2, a phosphor layer 3, a base 4, an upper support structure 5, a lower support structure 6, connection conductors 7 and 8, and a pulse starter 9. ing.
[0062]
  The arc tube 1 includes a translucent discharge vessel 1a, a pair of main electrodes 1b and 1b, an auxiliary electrode 1bA, a discharge medium (not shown), molybdenum foil 1c, lead wires 1d, 1e and 1f, and a heat insulating film 1g. The wall load depends on the rated lamp power 400W to 100W of the high-pressure discharge lamp.317.5-22.5 W / cm as shown in²Set to
[0063]
    FIG. 3 is a graph showing the relationship between the rated lamp power and the tube wall load in one embodiment of the metal halide lamp of the present invention together with that of the conventional example. In the figure, the horizontal axis is the rated lamp power (W), and the vertical axis is the tube wall load (W / cm).²) Respectively. In the figure, a straight line A shows the present embodiment, and a straight line B shows a conventional example.
[0064]
  As can be understood from the drawing, in this embodiment, the tube wall load is set to be relatively high.
[0065]
  The translucent discharge vessel 1a is configured by sealing both ends of a quartz glass tube, and includes a discharge space portion 1a1 and a pair of sealing portions 1a2, 1a3. Symbol 1a4 is an exhaust tip-off portion. The sealing portion 1a2 is on the upper side during lighting, and is formed by a pinch seal method so that the upper end portion of the discharge space portion 1a1 has a hemispherical shape.
[0066]
  The pair of main electrodes 1b is made of tungsten, and includes a shaft 1b1 and a coil 1b2 wound around the tip portion thereof. And the base end of the axis | shaft 1b1 is each embed | buried in sealing part 1a2, 1a3, and is welded to the molybdenum foil 1c. The molybdenum foil 1c is embedded in the sealing portions 1a2, 1a3 in an airtight manner.
[0067]
  The auxiliary electrode 1bA is made of a tungsten wire, and the base end thereof is embedded in the sealing portion 1a2, and is welded to the molybdenum foil 1c1, and the front end is located at a position facing the main electrode 1b with a small distance.
[0068]
  The lead-in wire 1d is welded at the tip to the molybdenum foil 1c and led out from the sealing portion 1a2.
[0069]
  The lead-in wire 1e is bent into a U shape having a pair of parallel legs, one leg is welded to the molybdenum foil 1c, and the other leg is embedded in the sealing part 1a3 as it is. Then, it is led out downward from the sealing part 1a3.
[0070]
  The leading end of the lead wire 1f is welded to the molybdenum foil 1c1 and led out from the sealing portion 1a2.
[0071]
  The heat insulating film 1g is applied to the outer surface of the portion surrounding the lower main electrode 1b in the figure of the translucent discharge vessel 1a.
[0072]
  The discharge medium is composed of a luminescent metal halide, a rare gas, and mercury.
[0073]
  The outer tube 2 is made of hard glass and has a BT shape having a spindle-shaped bulged portion 2a at the center, a neck portion 2b at the upper end, and a short cylindrical head portion 2c at the lower end, and the neck portion 2b. The flare stem 2d is sealed. The flare stem 2d introduces a pair of lead wires 2d1 and 2d2 in an airtight manner, and has an anchor wire 2d3 implanted therein.
[0074]
  As shown in FIG. 1, the phosphor layer 3 is formed on the inner surface of the entire outer tube OB except for the neck portion 2 b of the outer tube 12.
[0075]
  The base 4 is an E39 type base, and is fixed to the neck portion 2b of the outer tube 2, and one of the pair of lead wires 2d1 and 2d2 is connected to the shell portion and the other is connected to the center contact.
[0076]
  The upper support structure 5 includes a frame-shaped conductor 5a, a metal band 5b, and a ribbon conductor 5c. The frame-shaped conductor 5a is made of a conductive metal bar bent in an inverted U shape, and is supported in the outer tube 2 by welding the upper side to the lead-in wire 2d1 and the anchor wire 2d3. The metal band 5b supports the upper side of the arc tube 1 by holding the sealing portion 1a2 of the arc tube 1, and is welded to the lower ends of both leg portions of the frame-shaped conductor 5a. The ribbon conductor 5 c has a base end welded to the frame-shaped conductor 5 a and a tip end welded to the lead-in line 1 d of the arc tube 1. Thereby, the upper main electrode 1b of the arc tube 1 is connected to the shell portion of the base 4 through the molybdenum foil 1c, the lead-in wire 1d, the ribbon conductor 5c, the frame-shaped conductor 5a, and the lead-in wire 2d1 in series.
[0077]
  The lower support structure 6 supports the lower portion of the arc tube 1 and is electrically connected to the lower electrode 1b. The lower support structure 6 includes a frame-shaped conductor 6a, a spring piece 6b, a metal band 6c, a ribbon conductor 6d, and a getter 6e. I have. The frame-shaped conductor 6 a is bent in a U shape and supports the lower part of the arc tube 1 in the outer tube 2. The spring piece 6b has its pair of central portions welded to both sides of the lower portion of the frame-shaped conductor 6a, and both ends pressed against the inner surface of the head of the outer tube 2 to place the frame-shaped conductor 6a in the outer tube 2. is doing. The metal band 6c supports the lower side of the arc tube 1 by holding the sealing portion 1a3 of the arc tube 1, and is welded to the frame-shaped conductor 6a. The ribbon conductor 6 d connects between the frame-shaped conductor 6 a and the U-shaped lead-in line 1 e of the arc tube 1. The getter 6f cleans the inside of the outer tube 2, and its support is welded to and supported by the frame-shaped conductor 6a.
[0078]
  The connection conductor 7 is bent in an inverted L shape when viewed from the side, and is supported by being separated from the upper support structure 5 in the outer tube 2 by welding one side to the lead-in wire 2d2. On the other hand, the other connecting conductor 8 is made of a thin conductive wire, the upper end is welded to the other side of the connecting conductor 7, and the middle is curved and extends along the inner surface side of the outer tube 2, The lower end is welded to the frame-shaped conductor 6 a of the lower support structure 6. Thereby, the main electrode 1b under the arc tube 1 is connected to the center contact of the base 4 through the molybdenum foil 1c, the lead wire 1e, the frame conductor 6a, the connection conductors 7 and 8, and the lead wire 2a2 in series. Yes.
[0079]
  The pulse starter 9 includes a glow starter 9a, resistors 9b and 9c, an insulator 9d and a bimetal contact 9e. The pulse starter 9 operates only at the start and cooperates with the ballast B shown in FIG. Is generated in the arc tube 1.
[0080]
  That is, in the glow starter 9a, a pair of bimetal electrodes are sealed and sealed inside the discharge vessel, and a discharge medium mainly composed of argon is sealed inside. One external lead wire is connected to the frame-shaped conductor 5a of the upper support structure 5, and the other external lead wire is connected to one lead wire of the insulator 9d.
[0081]
  The resistor 9b is not necessarily clearly shown in FIG. 2, but one lead wire thereof is connected to one side of the connection conductor 7 and the other lead wire is connected to the bimetal contact 9e.
[0082]
  The resistor 9c has one lead wire connected to one support wire of the insulator 9d and the other lead wire connected to the lead wire 1f connected to the auxiliary electrode 1bA via the molybdenum foil 1c1. .
[0083]
  The insulator 9d has a structure in which support wires are planted at both ends of the insulator.
[0084]
  The bimetal contact 9e is a normally closed type and includes a bimetal plate 9e1 and a contact bar 9e2. The base end of the bimetal plate 9e1 is welded to the other support wire of the insulator 9d. The base end of the contact bar 9e2 is welded to the free end of the bimetal plate 9e1, and the end of the contact rod 9e2 contacts and separates from one support wire of the insulator 9d according to the displacement of the bimetal plate 9e1. That is, the bimetal contact 9e is supported by the insulator 9d and constitutes a contact mechanism in cooperation with the insulator 9d.
[0085]
  Next, the pulse starter 9 having the above configuration will be described with reference to FIG. 4 from the viewpoint of an electric circuit.
[0086]
    FIG. 4 is a circuit diagram showing the internal electrical connection and the lighting circuit of the metal halide lamp of the present invention in an embodiment of the metal halide lamp of the present invention.
[0087]
  In the figure, the same parts as those in FIG.
[0088]
  That is, the pulse starter 9 is connected in parallel with the arc tube 1 in a word. More specifically, a series circuit of a resistor 9b, a bimetal contact 9e and a glow starter 9a is connected to the arc tube 1 in parallel. In the figure, a series circuit of a resistor 9b, a glow starter 9a and a resistor 9d is connected between the lower main electrode 1b and the auxiliary electrode 1bA.
[0089]
  Further, the lighting circuit OC will be described. The lighting circuit OC is configured by interposing a switch SW and a ballast B between the AC power supply AS and the high-pressure discharge lamp HPL. That is, the input terminal of the ballast B is connected to both poles of the rated voltage 200V commercial AC power supply AS via the power switch SW, and the output terminal is connected to the base 4 of the metal halide lamp MHL via a lamp socket (not shown). .
[0090]
  The ballast B is mainly composed of a choke coil type inductor, and is configured so that the rated voltage is 200 V, a predetermined lamp voltage is formed in the metal halide lamp MHL, and the metal halide lamp MHL is lit stably. Yes.
[0091]
  Next, circuit operation will be described.
[0092]
  When the AC power supply AS is turned on, the secondary open circuit voltage of the ballast B is applied to the metal halide lamp MHL. However, the metal halide lamp MHL cannot be started only by applying the secondary open circuit voltage.
[0093]
  On the other hand, in the glow starter 9a, the bimetal electrodes are heated by the heat generated by the glow discharge, are displaced and eventually come into contact with each other, and a current limited to an appropriate value mainly by the resistor 9b flows to the ballast B. Next, at the moment when the pair of bimetal electrodes are dissociated by cooling, a starting pulse voltage generated by the back electromotive force is generated in the ballast B, and between the lower main electrode 1b and the auxiliary electrode 1bS in FIG. The starting pulse voltage is applied. As a result, an auxiliary discharge first occurs between the lower main electrode 1b and the auxiliary electrode 1bS, then develops into a main discharge between the main electrodes 1b and 1b, and the metal halide lamp MHL is started. When the metal halide lamp MHL starts and turns on and discharges to arc discharge, the bimetal contact 9e is heated by the radiant heat, so that it displaces from one lead wire of the resistor 9c and turns off. As a result, the glow starter 9a is opened to the AC power supply AS, so that it does not restart. The auxiliary electrode 1bA is opened when the bimetal contact 9e is turned off, and the series circuit of the auxiliary electrode 1bA, the resistor 9c, and the glow starter 9a has a parallel relationship with the lower main electrode 1b through discharge. However, since the resistance value of the resistor 9c is high, the glow starter 9a does not operate again, so that the auxiliary electrode 1bA is kept open. That is, the auxiliary electrode 1bA has no effect during lighting.
[Example 1]
[0094]
  The metal halide lamp shown in FIGS. 1 and 2 is as follows.
1 Metal halide lamp
    Rated lamp power: 400W
    Arc tube: Shape: Cylindrical, round on the top, V-shaped on the bottom
                    Inner diameter: 20mm
                    Distance between electrodes: 36mm
                    Tube wall load: 17.7 W / cm²
    Discharge medium: Halide (ScI₃+ NaI + NaBr = 32 mg),
                    Noble gas (Ar6.7 × 10³Pa) and Hg appropriate amount
    Phosphor layer: BaMgAl₁₀O₁₇: Eu / (Ba, Mg) O.6
                    Al₂O₃: Eu, Mn / YPVO₄: Eu / SiO₂
                    = 25/36/30/9 (both mass%), phosphor level
                    Average particle size 4μm, SiO₂Average particle size of 0.3 μm, phosphor layer
                    Linear transmittance of 65%
2 Ballast: Mercury lamp ballast for 400W
    FIG. 5 is a graph showing the spectral distribution of the phosphor layer having a wavelength of 410 nm or more in Example 1 of the metal halide lamp of the present invention. In the figure, the horizontal axis represents wavelength (nm) and the vertical axis represents radiation power (relative value). As can be seen from the figure, a blue emission peak with a wavelength of 450 nm, a green emission peak with a wavelength of 515 nm, and a red emission sub-peak with a wavelength of 595 nm appear from the phosphor layer 3.
[0095]
  The spectral distribution was determined by the method described in claim 1 using the following phosphors as the phosphors to be used.
[0096]
  Heat-resistant sample stage: Copper concave circular body having a diameter of 20 mm and a depth of 1 to 2 mm
  Pen-type mercury lamp: UVP INC. 11SC-1 type
  Instantaneous spectrometer: MCPD-3000 type manufactured by Otsuka Electronics Co., Ltd.
    FIG. 6 is a chromaticity diagram showing the chromaticity in the first embodiment. In the figure, the horizontal axis represents chromaticity x, and the vertical axis represents chromaticity y. The symbol ● indicates the chromaticity of this example, and the symbol ○ indicates that the phosphor layer is not provided.BookThe chromaticity of a transparent high-pressure discharge lamp having the same specifications as in the examples is shown. In addition, B. B. L is a curve indicating the chromaticity of black body radiation.
[0097]
  As can be seen from the figure, this example has a smaller chromaticity difference with respect to blackbody radiation than when no phosphor layer is provided, and the chromaticity difference between them is very close when x is 0 and y is 0.05. is doing. Further, the color temperature is approximately 4000K and substantially no difference is recognized.
[0098]
    FIG. 7 is a graph showing an ultraviolet spectral distribution at a wavelength of 280 to 380 nm in Example 1 of the metal halide lamp of the present invention. In the figure, the horizontal axis represents wavelength [nm], and the vertical axis represents relative power. Further, the ultraviolet irradiance of Example 1 was 9.5 μW / cm 2/1000 lx. Incidentally, the ultraviolet irradiance of the conventional diffusion metal halide lamp shown in FIG. 18 is 22.3 μW / cm.₂/ 1000 lx, and that of the transparent metal halide lamp shown in FIG. 19 is 25.3 μW / cm.²As is clearer than that of / 1000 lx, according to the present invention, it can be seen that the ultraviolet irradiation illuminance becomes an extremely small value that is half or less of that of the prior art.
[Example 2]
    Phosphor layer: BaMgAl₁₀O₁₇: Eu / (Ba, Mg) O.6
                    Al₂O₃: Eu, Mn / YPVO₄: Eu / SiO₂
                    = 18/27/46/9 (both mass%), phosphor level
                    Average particle size 4μm, SiO₂Average particle size of 0.3 μm, phosphor layer
                    Linear transmittance of 65%
[0099]
  Others are the same as Example 1..
[0100]
    FIG. 8 is a chromaticity diagram showing the chromaticity in Embodiment 2 of the metal halide lamp of the present invention together with that of the conventional example. In the figure, the horizontal axis represents chromaticity x, and the vertical axis represents chromaticity y. Also, the ● symbol is the chromaticity of this example, the ○ symbol is the chromaticity of a transparent metal halide lamp with the same specifications as the example except that no phosphor layer is provided, and the ▲ symbol isIt has the same specifications as the conventional example except that it does not have a phosphor layer.Chromaticity of transparent form, △ symbolHas a phosphor layerThe conventional chromaticity is shown respectively. In addition, B. B. L is a curve indicating the chromaticity of black body radiation. The conventional example has the same specifications as the present example except that the phosphor layer has the configuration described with reference to FIG.
[0101]
  As can be seen from the figure, in this embodiment, the chromaticity difference for black body radiation is smaller than that of the transparent type, and the chromaticity difference between the two is reduced.The
[0102]
  IeIn this embodiment, the chromaticity difference with respect to the black body radiation is smaller than that of the transparent type. The color temperature is almost 4250K, and no substantial difference is recognized.
[0103]
  On the other hand, when the diffusion type (Δ) provided with the phosphor layer of the conventional example is compared with the transparent type (Δ), the change in chromaticity is small, but the change in color temperature is large.
[0104]
    FIG. 9 is a graph showing the relationship between the lamp voltage and the total luminous flux in the second embodiment of the metal halide lamp of the present invention together with that of the transparent type. In the figure, the horizontal axis represents the lamp voltage (V), and the vertical axis represents the total luminous flux (lm). The symbol ■ indicates this example, and the symbol □ indicates a transparent type.
[0105]
  As can be seen from the figure, the total luminous flux of this embodiment is improved by about 3% compared to the transparent type, and the variation of the total luminous flux with respect to the lamp voltage is small.
[Example 3]
1 Metal halide lamp
    Rated lamp power: 1000W
    Arc tube: Shape; cylindrical
                    Inner diameter: 25mm
                    Distance between electrodes: 100mm
                    Tube wall load: 12.7 W / cm²
    Discharge medium: Halide (ScI₃+ NaI = 68.6 mg,
                    CsI = 0.8 mg), noble gas (Ar1.3 × 10³Pa)
                    And Hg proper amount
    Phosphor layer: BaMgAl₁₀O₁₇: Eu / (Ba, Mg) O.6
                    Al₂O₃: Eu, Mn / YPVO₄: Eu / SiO₂
                    = 25/36/30/9 (both mass%), phosphor level
                    Average particle size 4μm, SiO₂Average particle size of 0.3 μm
2 Ballast: 1000W dedicated ballast
    FIG. 10 is a chromaticity diagram showing chromaticity in the third embodiment. In the figure, the horizontal axis represents chromaticity x, and the vertical axis represents chromaticity y. Further, the ● symbol indicates the chromaticity of this embodiment, and the ◯ symbol indicates the chromaticity of a transparent metal halide lamp having the same specifications as this embodiment except that no phosphor layer is provided. In addition, B. B. L is a curve indicating the chromaticity of black body radiation.
[0106]
  As can be seen from the figure, according to this embodiment, the chromaticity difference from the black body radiation x is smaller than that of the transparent type. Moreover, the color temperature of both is about 4300-4400K, and a difference is hardly recognized.
[Example 4]
[0107]
  The metal halide lamp shown in FIGS. 1 and 2 is as follows.
1 Metal halide lamp
    Rated lamp power: 400W
    Arc tube: Shape: Cylindrical, round on the top, V-shaped on the bottom
                    Inner diameter: 20mm
                    Distance between electrodes: 36mm
                    Tube wall load: 17.7 W / cm²
    Discharge medium: Halide (ScI₃+ NaI + NaBr = 32 mg)
                    , Noble gas (Ar 6.7 × 10³Pa) and Hg appropriate amount
    Phosphor layer: BaMgAl₁₀O₁₇: Eu / YPVO₄: Eu
                    / SiO₂= 64/31/5 (both mass%), fluorescence
                    Body average particle size 4μm, SiO₂Average particle size of 0.3 μm
2 Ballast: Mercury lamp ballast for 400W
[Example 5]
    Phosphor layer 3: BaMgAl₁₀O₁₇: Eu / YPVO₄: Eu
                    / SiO₂= 47.5 / 47/5 (both mass%),
                    Phosphor average 4 μm, SiO₂Average particle size of 0.3 μm
[0108]
  Others are the same as Example 1..
[Example 6]
1 Metal halide lamp
    Rated lamp power: 1000W
    Arc tube: Shape; cylindrical
                    Inner diameter: 25mm
                    Distance between electrodes: 100 mm
                    Tube wall load: 12.7 W / cm²
    Discharge medium: Halide (ScI₃+ NaI = 68.6 mg,
                    CsI = 0.8 mg), noble gas (Ar1.3 × 10³Pa)
                    And Hg proper amount
    Phosphor layer: BaMgAl₁₀O₁₇: Eu / YPVO₄: Eu
                    / SiO₂= 64/31/5 (both mass%),
                    Phosphor average particle size 4μm, SiO₂Average particle size of 0.3 μm
2 Ballast: 1000W dedicated ballast
    FIG. 11 is a graph showing the relationship between the lamp voltage and the total luminous flux in Example 3 of the metal halide lamp of the present invention together with that of the transparent type. In the figure, the horizontal axis represents the lamp voltage (V), and the vertical axis represents the total luminous flux (lm). The symbol ● represents the present embodiment, and the symbol ○ represents a transparent shape.
[0109]
  As can be seen from the figure, according to the present embodiment, the variation of the total luminous flux with respect to the lamp voltage is smaller than that of the transparent type, and the total luminous flux values are substantially equal.
[0110]
    FIG. 12 is a graph showing the relationship between the total luminous flux and the phosphor blending ratio in an embodiment of the metal halide lamp of the present invention. The vertical axis represents the total luminous flux value (lm).
[0111]
    FIG. 13 is a graph showing the relationship between the average color rendering index and the phosphor blending ratio. The vertical axis represents the average color rendering index Ra.
[0112]
    FIG. 14 is a graph showing the relationship of the correlated color temperature to the phosphor blending ratio. The vertical axis represents the correlated color temperature Tc (K).
[0113]
    FIG. 15 is a graph showing the relationship of the chromaticity difference with respect to the phosphor blending ratio. The vertical axis represents the chromaticity difference duv. Indicates.
[0114]
  12 to 15, the BGr blending ratio (%) on the horizontal axis represents the phosphor BaMgAl that emits blue-green light to the entire phosphor.₁₀O₁₇: Eu and (Ba, Mg) O.6Al₂O₃: Eu, Mn (hereinafter referred to as “BGr”) compounding ratio. Therefore, the numerical value obtained by subtracting the phosphor ratio from 100% is YPVO.₄: Eu (hereinafter referred to as “Re”) ratio. The symbol □ indicates the case of BGr: Re = 1: 3.
[0115]
  As can be seen from each figure, the total luminous flux tends to be relatively higher when BGr: Re = 1: 1 and BGr: Re = 2: 1 than when BGr: Re = 1: 3. . The average color rendering index Ra is almost the same in any mixing ratio. The correlated color temperature Tc tends to be slightly higher when BGr: Re = 1: 1 and BGr: Re = 2: 1 than when BGr: Re = 1: 3. Chromaticity difference duv. Is slightly larger when BGr: Re = 1: 1, but decreases when BGr: Re = 2: 1.
[0116]
【The invention's effect】
    According to each invention of Claims 1 thru | or 4, the discharge medium containing Na and Sc enclosed in the translucent discharge container, a pair of electrodes sealed in the translucent discharge container, and the translucent discharge container. Europium and manganese which are disposed inside the arc tube, the outer tube, and the outer tube and have blue light emission (B) having an emission peak wavelength of 440 to 460 nm and green light emission (G) having a light emission peak wavelength of 505 to 525 nm, respectively. Activated aluminate phosphorConsist ofA first phosphor and a europium-activated yttrium vanadate phosphate phosphor having a red light emission (R) of 585 to 605 nmConsist ofAnd a second phosphor, and a phosphor layer in which the peak ratio of the radiant power of each color emission satisfies the following formula, whereby the total luminous flux comprises the phosphor layer. It is possible to provide a diffusion-type metal halide lamp that is substantially equal to or higher than that of the transparent type that does not, and that the color temperature hardly changes compared to that of the transparent type and that the amount of ultraviolet radiation is small.
[0117]
            B: G: R = 0.5 to 1.1: 1.0 to 1.7: 1.0
    According to the invention of claim 2, in addition, since the lamp power is 500 W or less and the tube wall load is 16 to 30 W / cm 2, the amount of ultraviolet rays that irradiate the phosphor layer increases, and light emission from the phosphor And a diffusion type metal halide lamp with a small chromaticity difference can be provided.
[0118]
    According to the invention of claim 3, in addition, the phosphor layer is disposed on the inner surface of the outer tube, and the linear transmittance of the outer tube at the position where the phosphor layer is disposed is before the phosphor layer is disposed. To provide a diffusion-type metal halide lamp with little change in color temperature and chromaticity when compared with a transparent high-pressure discharge lamp, when the linear transmittance is 100%. it can.
[0119]
    Claim4According to the invention, in addition, the phosphor layer can provide a diffusion-type metal halide lamp having a large total luminous flux because the average particle diameter of the phosphor is 5 μm or less.
[0120]
    Claim5According to the invention, in addition, the phosphor layer contains 5 to 15% by mass of silicon dioxide SiO2, so that the diffusion type metal halide having the phosphor layer having a required binding force and hardly peeled off. A lamp can be provided.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of a metal halide lamp of the present invention.
FIG. 2 is a front view showing a state where the phosphor layer is also removed.
FIG. 3 is a graph showing the relationship between the rated lamp power and tube wall load in one embodiment of the metal halide lamp of the present invention together with that of a conventional example.
FIG. 4 is a circuit diagram showing the internal electrical connection and the lighting circuit of the high-pressure discharge lamp of the present invention in an embodiment of the metal halide lamp of the present invention.
FIG. 5 is a graph showing a spectral spectrum distribution of the entire light emission wavelength of 410 nm or more in Example 1 of the metal halide lamp of the present invention.
6 is a chromaticity diagram showing chromaticity in Example 1 as well. FIG.
FIG. 7 is a graph showing an ultraviolet spectral distribution at a wavelength of 280 to 380 nm in Example 1 of the metal halide lamp of the present invention.
FIG. 8 is a chromaticity diagram showing chromaticity in Embodiment 2 of a metal halide lamp of the present invention together with that of a conventional example.
FIG. 9 is a graph showing the distribution of the relationship between the lamp voltage and the total luminous flux together with the transparent type in Example 2 of the metal halide lamp of the present invention.
FIG. 10 is a chromaticity diagram showing chromaticity in Embodiment 3 of a metal halide lamp of the present invention together with that of a conventional example.
FIG. 11 is a graph showing the distribution of the relationship between the lamp voltage and the total luminous flux together with the transparent type in Example 3 of the metal halide lamp of the present invention.
FIG. 12 is a graph showing the relationship between the total luminous flux and the phosphor blending ratio in an embodiment of the metal halide lamp of the present invention.
FIG. 13 is a graph showing the relationship between the average color rendering index and the phosphor blending ratio.
FIG. 14 is a graph showing the relationship of the correlated color temperature to the phosphor blending ratio.
FIG. 15 is a graph showing the relationship between the chromaticity difference and the phosphor blending ratio.
FIG. 16 is a graph showing a spectral spectrum distribution of a phosphor layer used in a conventional diffusion metal halide lamp.
FIG. 17 is a graph showing the distribution of the relationship between the lamp voltage and the total luminous flux in conventional transparent and diffusive metal halide lamps.
FIG. 18 is a graph showing an ultraviolet spectral distribution at a wavelength of 280 to 380 nm in a conventional diffusion metal halide lamp.
FIG. 19 is a graph showing an ultraviolet spectral distribution at a wavelength of 280 to 380 nm in a conventional transparent metal halide lamp.
[Explanation of symbols]
      1 ... arc tube
      2 ... Outer pipe
      3 ... phosphor layer
      4 ... The base
      5 ... Upper support structure
      6 ... Lower support structure
      7 ... Connection conductor
      8 ... Connection conductor
      9 ... Pulse starter
      MHL ... Metal halide lamp

Claims (5)

A translucent discharge vessel in which a discharge space is formed; at least a pair of electrodes sealed in the translucent discharge vessel and present in the discharge space of the translucent discharge vessel; and at least Na and Sc halides An arc tube comprising a discharge medium including and enclosed in a translucent discharge vessel;
An outer tube that houses the arc tube;
A first phosphor composed of europium and manganese-activated aluminate phosphor and a second phosphor composed of europium-activated yttrium phosphate vanadate phosphor and disposed in the outer tube; The first phosphor has a blue emission (B) with an emission peak wavelength of 440 to 460 nm and a green emission (G) with an emission peak wavelength of 505 to 525 nm, and the second phosphor has a red color with an emission peak wavelength of 585 to 605 nm. A phosphor layer having a system light emission (R) and a peak ratio of radiation power of each color system light emission satisfying the following formula;
A metal halide lamp characterized by comprising:
B: G: R = 0.5-1.1: 1.0-1.7: 1.0 Arc tube in the lamp power is 500W or less, according to claim 1, wherein the metal halide lamp tube wall load is characterized by a 16~30W / cm ^2. The phosphor layer is disposed on the inner surface of the outer tube, and the linear transmittance of the outer tube at the position where the phosphor layer is disposed is 100% before the phosphor layer is disposed. The metal halide lamp according to claim 1 or 2, wherein the content is 55 to 70%. The metal halide lamp according to any one of claims 1 to 3 , wherein the phosphor layer has an average particle size of the phosphor of 5 µm or less. The phosphor layer, 5 to 15 wt% of claims 1 to any one description of a metal halide lamp 4, characterized by containing silicon dioxide SiO _2.

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