JP2006128134A - Metal halide discharge lamp, metal halide discharge lamp direct current lighting device and lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal halide discharge lamp, a metal halide discharge lamp direct current lighting device and a lighting system utilizing the same, the metal halide discharge lamp disusing mercury heavily loading environment, having almost the same electrical and light emitting performance as the one with mercury sealed in, and having little color irregularity when lighted with a direct current. <P>SOLUTION: In the metal halide discharge lamp, a first halide is a halide of one or a plurality of Na, Sc, and rare earth metal, and a second halide is a metal halide of one or a plurality of Mg, Fe, Co, Cr, Zn, Ni, Mn, Al, Sb, Be, Re, Ga, Ti, Zr, and Hf. The metal halide discharge lamp is mounted with a discharge medium containing rare gas, and is constituted to be lighted with the direct current. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metal halide discharge lamp that essentially does not enclose mercury, a metal halide discharge lamp DC lighting device using the same, and an illumination device.

  BACKGROUND ART A metal halide discharge lamp in which a rare gas, a luminescent metal halide and mercury are enclosed in an arc tube having a pair of electrodes facing each other is widely used because of its relatively high efficiency and high color rendering.

  Metal halide discharge lamps are classified into short arc type and long arc type.

  Short arc type metal halide discharge lamps are used in projections such as liquid crystal projectors and overhead projectors that condense the light emitted from the lamps and project them onto a screen, and in store lighting such as downlights and spotlights. Recently, small and short arc metal halide discharge lamps have been used in place of halogen bulbs as automotive headlamps.

  The specification of a metal halide discharge lamp for automobile headlamps is described in, for example, Japanese Patent Laid-Open No. 2-7347, but it is indispensable to enclose about 2 to 15 mg of mercury.

  By the way, there is a need for a metal halide discharge lamp that does not require the encapsulation of mercury, and one that meets this need is known (see Patent Document 1). The invention is intended to obtain a required lamp voltage by sealing helium or neon at a pressure of 100 to 300 Torr instead of mercury. Further, since these noble gases have small atomic radii, Since it permeate | transmits, it is the structure of forming an airtight container with translucent ceramics.

  On the other hand, long arc type metal halide discharge lamps are mainly used for general lighting such as lighting devices for high ceilings, floodlights, street lamps, and lighting devices for roads. Further, a metal halide discharge lamp that generates ultraviolet rays is used for a photo-curable synthetic resin or ink. The metal halide discharge lamp used for this purpose is also a long arc type.

  By the way, the metal halide discharge lamps currently in practical use both require mercury in the short arc type and the long arc type. This is because mercury is used in a metal halide discharge lamp to obtain a desired lamp voltage and maintain electrical characteristics.

  That is, for example, if the lamp voltage is low, the lamp current must be increased in order to obtain the desired lamp input. In this case, an increase in current capacity and an increase in generated heat of related equipment such as a lighting device, a lighting fixture, and wiring become problems.

  In addition, when the lamp current is large, there is a problem that the lamp efficiency is lowered with an increase in electrode loss. That is, since the electrode drop voltage of a metal halide discharge lamp is constant depending on the lamp, if the lamp voltage is low, it is necessary to increase the lamp current to compensate for this, so the electrode loss increases in proportion to the lamp current, and the lamp efficiency Will fall.

  Therefore, in general, in a discharge lamp, it is advantageous to set the lamp voltage as close as possible to the lamp input voltage, that is, as high as possible within a range where the arc does not go out.

  Next, the reason why the mercury sealing is necessary will be described while considering the lamp voltage.

  FIG. 27 is a conceptual diagram for explaining a lamp voltage in a metal halide discharge lamp. In the figure, 1 is an airtight container, 2 and 2 are electrodes, and 3 and 3 are lead wires.

  The lamp voltage Vl is a voltage appearing between the lead wires 3 and 3 in the lighting state of the metal halide discharge lamp.

  A distance L between the electrodes 2 and 2 is referred to as an interelectrode distance.

The lamp voltage Vl can be expressed by Equation 1.
[Formula 1]
Vl = E × L + Vd
Here, E is the potential gradient of the plasma between the electrodes, and Vd is the electrode drop voltage.

The plasma potential gradient E can be expressed by Equation 2.
[Formula 2]
E = I / 2π∫σr dr
Here, I is the lamp current, σ is the electrical conductivity of the plasma, and is a function of the temperature T. r is a radial distance from the center to an arbitrary position.

Assuming that the substance A is present in the discharge space during the lighting of the metal halide discharge lamp, the electrical conductivity σ at the temperature T of the substance A can be expressed by Equation 3.
[Formula 3]
σ = C · N _E / (T ^1/2 · (N _A · Q))
Here, C is a constant, N _E is the electron density, the N _A density of the material, Q is the collision cross section for electron substances A.

  It can be seen from Equation 1 that the ramp voltage Vl increases as the potential gradient E increases and the interelectrode distance L increases.

  Further, it can be seen from Equation 2 that the potential gradient E increases as the electrical conductivity σ decreases and the lamp current I increases.

Furthermore, the electrical conductivity sigma, from Equation 3 as N _E is small, N _A and Q is can be seen that the larger small.

Therefore, if the distance L between electrodes and the lamp current I is constant, the conditions of substance A lamp voltage Vl is increased, (. Which is suppressed to a small N _E) ionization difficult, density in the lamp increase the (N _A This is because the collision cross-sectional area Q with electrons is large.

  Thus, mercury is a substance that has a very high vapor pressure (1 atm at 361 ° C.), is difficult to ionize, and has a large cross-sectional area of collision with electrons.

  Therefore, a desired lamp voltage can be easily obtained by adjusting the amount of mercury enclosed according to the lamp size.

  Thus, in a conventional metal halide discharge lamp, the use of mercury makes it possible to easily obtain a desired lamp voltage, which is why mercury is used.

By the way, in the case of a metal halide discharge lamp, it is necessary to increase the vapor pressure of mercury in order to ensure a required lamp voltage as the distance between the electrodes is small and the electrode L is short. For example, in a small short arc metal halide discharge lamp having an arc tube with an internal volume of 1 cc or less, the mercury vapor pressure during lighting becomes 20 atmospheres or more.
Japanese Patent Laid-Open No. 3-11205

  Hereinafter, the problem of enclosing mercury in a metal halide discharge lamp and the problem of not enclosing conventional mercury will be described separately.

  1. About the problem of enclosing mercury.

  At present, environmental issues are very close up on a global scale. In the lighting field, it is very important to reduce mercury from the lamp, which is an environmentally hazardous substance that has a negative impact on the environment, and even to eliminate it. It is considered a serious problem.

  Therefore, the biggest problem of the conventional metal halide discharge lamp is that it encloses mercury.

  In addition, the metal halide discharge lamp in which mercury is enclosed to obtain a desired lamp voltage has many problems as described below.

    Other problem 1: The start-up of the spectral characteristics at the start is poor.

  When a metal halide discharge lamp is used for an automobile headlamp, an instantaneous rise of a luminous flux is required. For this purpose, a lighting method is adopted in which xenon is sealed at a high pressure as a starting gas, a large current is supplied at the beginning of lighting, and the current is reduced as time passes. Although instant rise is possible in this way, mercury evaporates rapidly when the switch is turned on. Therefore, mercury loses energy, and the rise of the vapor pressure of the light-emitting metal is slow. Continues until ~ 20 seconds later. Mercury luminescence is inferior in color characteristics, so color rendering is poor and chromaticity does not fall within the white range. Thus, the rise of spectral characteristics is very bad. Therefore, it takes a long time to emit light with the desired spectral characteristics.

    Other problem 2: Not suitable for dimming.

  That is, when the temperature of the arc tube changes, the color temperature of the emitted light changes greatly, and the color rendering properties change accordingly. This will be described below with reference to FIG.

    FIG. 28 is a graph showing an emission spectrum distribution of a conventional short arc type metal halide discharge lamp for projection. In the figure, the horizontal axis represents wavelength (nm), and the vertical axis represents relative radiation power (%).

The conventional short arc type metal halide discharge lamp, argon 500Torr as the rare gas, and the dysprosium iodide as a halide (DyI ₃₎ to 1mg and neodymium iodide (NdI ₃₎ 1mg, and mercury (Hg) and 13mg encapsulated Is.

  The emission spectrum is composed of continuous emission by dysprosium and neodymium and main emission line spectra by elements each having a symbol on the arrow, and it can be seen that the emission line spectrum by mercury has a large power.

  By the way, the amount of light emitted by each light emitting metal changes in proportion to the vapor pressure in the lamp.

  The vapor pressure of the halide of the luminescent metal is significantly lower than that of mercury. Therefore, if the temperature of the arc tube changes, the vapor pressure of the luminescent metal changes due to the change in the evaporation amount of the halide. The amount of luminescence changes.

  On the other hand, since the vapor pressure of mercury is very high, it does not change so much even if the temperature of the arc tube changes, so the amount of light emitted by the strong emission line spectrum of mercury does not change much.

  Therefore, when the input power to the arc tube is reduced, light emission by mercury is relatively dominant, so that the color temperature of light emission is lowered and the color rendering properties are lowered. This means that a conventional metal halide discharge lamp enclosing mercury is not suitable for dimming.

  In the case of automotive headlamps, dimming is necessary for daytime lighting (daylighting) used in Europe and the United States, but in conventional metal halide discharge lamps that contain mercury, color characteristics are required. Will drop significantly.

    Other problem 3: Variation in characteristics is large.

Mercury-filled metal halide discharge lamps tend to vary in characteristics even with the same input because the temperature of the arc tube varies with the dimensional variations of individual lamps.
In addition, the characteristics are likely to change due to an increase in the coldest part temperature due to blackening of the arc tube during the long life.

  For this reason, when it illuminates using a some metal halide discharge lamp like a shop etc., it becomes easy to become a problem especially.

    Other problem 4: Instantaneous restart is difficult.

  In the short arc type small metal halide discharge lamp, since the distance between the electrodes is small, the mercury vapor pressure is set high to obtain a required lamp voltage, and the mercury vapor pressure becomes 20 atm or more during lighting.

  Furthermore, in a headlight for an automobile, high-pressure xenon is enclosed in order to speed up the rise of the luminous flux as described above, and xenon is about 35 atm during lighting. Thus, since the mercury vapor pressure and the xenon vapor pressure during lighting are very high, in order to restart, a very high and high power pulse voltage must be applied. This not only makes the lighting circuit expensive, but it is also necessary to insulate the circuit, the lamp and the appliances that house them from high voltages.

    Other problem 5: The arc tube tends to burst.

  As described above, since the mercury vapor pressure at the time of lighting is high, the arc tube is easily ruptured due to the initial distortion or the distortion increasing during long-term lighting. This problem significantly reduces lamp reliability.

    Other problem 6: The screen illuminance is low for projection.

  In the case of a short arc type metal halide discharge lamp, when condensing through an optical system such as a liquid crystal projector using this lamp as a light source, and projecting to illuminate a large amount of illuminance on an irradiated surface, for example, a screen, It is important how light emitted from the discharge lamp passes through the optical system without loss and reaches the irradiation surface. In order to reduce the loss and improve the illumination intensity of the irradiated surface, the arc of the discharge lamp needs to be narrowed down. The fact that the arc is constricted means that the arc temperature distribution is steep.

  However, mercury emission is absorbed and optically thick, and the temperature rises due to absorption of energy in the middle and low temperature parts, so the arc temperature distribution spreads in a parabolic shape, thus constricting the arc. I can't.

  On the other hand, when scandium or rare earth metal is used as the light emitting metal and the light emission is greatly increased, it is known that the arc can be narrowed down even in the presence of mercury. However, in the above case, if the lighting pressure of mercury is high, the convection becomes intense and the arc becomes unstable and cannot be put to practical use.

  2. About the problem when conventional mercury is not sealed.

  In the above-described metal halide discharge lamp that does not enclose mercury, helium or neon has a remarkably high pressure during operation. Therefore, if it is made to withstand this, a metal halide discharge lamp that does not enclose mercury can be obtained. Therefore, it can be evaluated in many respects in that a metal halide discharge lamp that does not enclose mercury can be obtained.

  However, it is quite difficult to realize a structure similar to that of a conventional metal halide discharge lamp in which mercury is sealed at a high pressure during lighting. For example, in a small metal halide discharge lamp, when the required lamp voltage is 50 to 60 V, the pressure of helium or neon during lighting will exceed 150 atm. High reliability against rupture cannot be obtained.

  The present invention can form a required lamp voltage without essentially enclosing mercury, which has a large environmental load, and has almost the same electrical and light emission characteristics as a metal halide discharge lamp encapsulating mercury, and has a good luminous flux rise. It is a general object to provide a metal halide discharge lamp, a metal halide discharge lamp DC lighting device and a lighting device using the same.

  In addition, a specific object of the present invention is to provide a metal halide discharge lamp with little color unevenness due to direct current lighting, a metal halide discharge lamp direct current lighting device using the same, and an illumination device.

  Furthermore, the present invention is secondary to provide a metal halide discharge lamp that does not have a low heat loss and does not decrease luminous efficiency even though mercury is not enclosed, and a metal halide discharge lamp DC lighting device and lighting device using the metal halide discharge lamp. Purpose.

  Furthermore, the present invention provides a metal halide discharge lamp that can be lit with a direct current to reduce light color difference and color separation and reduce the lighting circuit, and a metal halide discharge lamp direct current lighting device and lighting device using the metal halide discharge lamp. Next purpose.

  Furthermore, it is a secondary object of the present invention to provide a metal halide discharge lamp suitable for a headlamp of a moving body such as an automobile, a metal halide discharge lamp DC lighting device and an illumination device using the metal halide discharge lamp.

  Furthermore, the present invention is a practical metal halide discharge lamp that is less likely to rupture during lighting, even if it is an airtight container having a mechanical strength equivalent to that of a conventional one that encloses mercury, and a metal halide discharge using the same. It is a secondary object to provide a lamp direct current lighting device and a lighting device.

    The metal halide discharge lamp of the invention of claim 1 is a fire-resistant and light-transmitting hermetic container; a pair of electrodes sealed in the hermetic container and operating as an anode and the other as a cathode; 1 halide, 2nd halide, and rare gas, and is enclosed in an airtight container in an essentially mercury-free configuration, and the first halide is composed of sodium Na, scandium Sc, and a rare earth metal. One or a plurality of halides selected from the group, the second halide is magnesium Mg, iron Fe, cobalt Co, chromium Cr, zinc Zn, nickel Ni, manganese Mn, aluminum Al, antimony Sb , Beryllium Be, rhenium Re, gallium Ga, titanium Ti, zirconium Zr and hafnium Hf One or a discharge medium is a plurality of kinds of metal halide selected from; comprises a metal halide discharge lamp, characterized in that it is configured to illuminate at DC.

  In the present invention and each of the following inventions, the definitions and technical meanings of terms are as follows unless otherwise specified.

  [Air-tight container] A fire-resistant and light-transmitting air-tight container is a material with fire resistance that can sufficiently withstand the normal operating temperature of the discharge lamp, and visible light in the desired wavelength range generated by the discharge to the outside. It may be made of anything as long as it can be derived. For example, quartz glass, translucent alumina, ceramics such as YAG, or single crystals thereof 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 hermetic container.

  [Regarding Electrode] The metal halide discharge lamp of the present invention is configured to be lit with a direct current. That is, the pair of electrodes operates as one anode and the other as a cathode. In general, since the temperature of the anode is greatly increased, an anode having a larger heat radiation area than the cathode is used.

  Further, regarding the interelectrode distance formed between a pair of electrodes, in the present invention, the metal halide discharge lamp may be a short arc type or a long arc type.

  The short arc type is a so-called stable electrode type in which arc discharge is stabilized by electrodes by reducing the distance between the electrodes formed in the hermetic container. For this reason, the light emission of the discharge lamp can be brought as close to the point light source as possible, so that the light can be efficiently collected by an optical system such as a reflecting mirror or a lens. In the case of headlamps for moving objects such as liquid crystal projectors and automobiles, small short arc type metal halide discharge lamps are used. The distance between electrodes of such metal halide discharge lamps is actually 6 mm. The following are preferred. That is, when the distance between the electrodes exceeds 6 mm, the distance from the point light source is increased, and the focal characteristic of the optical system is deteriorated. For example, when used as a light source for a liquid crystal projector, the screen illuminance decreases.

  Accordingly, in the present invention, a small and short arc type metal halide discharge lamp means a lamp having a distance between electrodes of 6 mm or less. However, it is preferably 4 mm or less, and optimally 1 to 3 mm for projection such as a liquid crystal projector. The distance between the electrodes is measured at the tip of the electrode.

  On the other hand, the long arc type refers to a so-called tube wall stable type in which arc discharge is stabilized on the inner surface of the hermetic container by making the distance between the electrodes formed in the hermetic container larger than the inner diameter of the hermetic container. Long arc type metal halide discharge lamps are widely used for general lighting and the like.

  [Discharge Medium] In the present invention, the discharge medium essentially consists of the first halide, the second halide and the rare gas as described above.

  The first halide is a metal halide that generates the desired light emission, for example, visible light or ultraviolet light. In order to use visible light, when the metal halide that efficiently generates visible light is used as the first halide, generally, the metal halide does not necessarily have a high vapor pressure during lighting.

  The second halide is a metal halide having a high vapor pressure, and mainly determines the lamp voltage in the metal halide discharge lamp. Note that “the vapor pressure is high” means that the vapor pressure during lighting is high, but it is not necessary to be too high like mercury, and preferably the pressure in the airtight container during lighting is about 5 atm or less. is there. Therefore, it is not limited to a specific metal halide as long as the above conditions are satisfied.

Table 1 illustrates a second halide effective in the practice of the present invention, along with the temperature at which its vapor pressure is 1 atmosphere. Note that these values are somewhat different depending on literatures, and therefore the temperature values in Table 1 are approximate values.
[Table 1]
No. Second halide Temperature at 1 atm (° C)
1 AlI ₃ 422
2 FeI ₂ 827
3 ZnI ₂ 727
4 SbI ₃ 427
5 MnI ₂ 827
6 CrI ₂ 827
7 GaI ₃ 349
8 ReI ₃ 627
9 MgI ₂ 927
10 CoI ₂ 827
11 NiI ₂ 747
12 BeI ₂ 487
13 TiI ₄ 377
14 ZrI ₄ 431
15 HfI ₄ 427

Most of the halides shown in Table 1 have a vapor pressure lower than that of mercury, and the adjustment range of the lamp voltage is narrower than that of mercury. However, the adjustment range of the lamp voltage can be expanded by mixing and enclosing a plurality of these as required. For example, when AlI ₃ is in an incompletely evaporated state and a desired lamp voltage is not obtained, the lamp voltage does not change even if AlI ₃ is added.

On the other hand, if ZnI ₂ is added instead of adding AlI ₃ , the lamp voltage corresponding to the action of ZnI ₂ is added, so that the lamp voltage can be increased.

  Furthermore, if another second halide is added, a higher lamp voltage can be obtained.

  The second halide is also a metal halide that does not easily emit light in the visible region as compared to the metal of the first halide. The phrase “difficult to emit light in the visible range compared to the metal of the first halide” does not mean that visible light is less emitted in an absolute sense, but a relative meaning. For sure, Fe and Ni emit more in the ultraviolet region than in the visible region, but Ti, Al, Zn and the like emit more in the visible region. Therefore, when these metals that emit a lot of light in the visible region are caused to emit light alone, energy is concentrated on the metal, so that there is much light in the visible region. However, if the metal of the second halide is higher in energy level than the metal of the first halide and is difficult to emit light, the energy is reduced in the state where the first and second halides coexist. Since it concentrates on the light emission of the first halide, the light emission of the metal of the second halide is reduced.

  Therefore, the second halide is not prohibited from emitting visible light, but has a small influence on the total visible light emitted by the discharge lamp and has little influence.

  Furthermore, in the present invention, in addition to the first and second halides, a third halide is sealed as necessary for the purpose of correcting the arc temperature distribution and reducing heat loss. Can do.

  The halogen will be described. As the halogen constituting the first and second halides, the most suitable reactivity is iodine, and the reactivity increases in the order of bromine, chlorine, and fluorine. Also good. Further, different halogen compounds such as iodide and bromide can be used in combination.

  The rare gas is sealed at a pressure of 1 atm or more, and acts as a starting gas and a buffer gas. The type of the rare gas is not particularly limited as long as it is a gas that does not pass through the hermetic container. However, since neon easily penetrates quartz glass, argon, krypton, or xenon is recommended as a rare gas in the present invention when an airtight container is formed of quartz glass.

  Increasing the noble gas sealing pressure to 1 atm or higher can improve the luminous flux rise characteristics of the metal halide discharge lamp. Good light beam rise characteristics are convenient for any purpose of use, but are particularly important for headlamps of mobile objects such as automobiles, liquid crystal projectors, and the like.

  Explain about mercury. In the present invention, “essentially mercury is not enclosed” means that mercury is contained in an amount of less than 0.3 mg, preferably 0.2 mg or less per 1 cc of the inner volume of the airtight container, in addition to not containing mercury at all. It means to allow that.

  However, it is environmentally desirable not to enclose mercury at all.

  In the case of maintaining the electrical characteristics of the discharge lamp with mercury vapor as in the conventional case, the short arc type is sealed because 20 mg or more per 1 cc of the internal volume of the hermetic container, and the long arc type is also filled with 5 mg or more. In other words, it can be said that the present invention has a substantially small amount of mercury.

  [Operation] Next, the operation of the present invention will be described. In the present invention, one or more halides selected from the group consisting of sodium Na, scandium Sc, and rare earth metals are encapsulated as the first halide without essentially encapsulating mercury. Therefore, the metal of the first halide emits mainly visible light, and magnesium Mg, iron Fe, cobalt Co, chromium Cr, zinc Zn, nickel Ni, manganese Mn, aluminum Al, antimony Sb as the second halide. Since the halide of one or more metals selected from the group consisting of beryllium Be, rhenium Re, gallium Ga, titanium Ti, zirconium Zr, and hafnium Hf is encapsulated, the lamp voltage is mainly used for the second voltage. Determined by halide.

  Therefore, the metal halide discharge lamp of the present invention operates as desired without essentially enclosing mercury, and exhibits electrical and light emission characteristics substantially equivalent to those of the prior art in which mercury is encapsulated. When the second halide is incompletely evaporated, the amount of evaporation is determined by the vapor pressure of the second halide. The vapor pressure of the halide is determined by the coldest part temperature. The vapor pressure during lighting of the second halide is lower than that of mercury, but is clearly higher than that of the first halide and may be about 5 atmospheres or less.

  In the above description, “substantially” means that there is a difference that is somewhat inferior within a practical range as compared with the prior art. In view of the fact that this type of metal halide discharge lamp may be lit by an electronic lighting device, it is in a practically acceptable range. However, if desired, the lamp voltage can be further increased by applying a heat retaining means described later to the hermetic container.

  Further, in the present invention, one of the pair of electrodes operates as an anode and the other operates as a cathode, that is, is configured for direct current lighting, and therefore exhibits the following useful actions.

  That is, when a conventional metal halide discharge lamp enclosing mercury is dc-lighted, the luminescent metals such as sodium Na and scandium Sc are positively ionized, and therefore are attracted to the cathode side, and the anode side is luminescent metal compared to the cathode side. The concentration of becomes smaller. On the other hand, some mercury is also attracted to the cathode side, but since the amount of mercury is overwhelmingly large, a sufficient amount of mercury is also present on the anode side. As a result, the light emitting metal emits sufficient light on the cathode side, but the light emission of the light emitting metal is significantly weakened on the anode side, and the light emission of mercury is mainly performed. For this reason, remarkable color separation is caused between the electrodes, which is not suitable for practical use. Therefore, in an application field where color separation is a problem, metal halide discharge lamps containing mercury are exclusively used by alternating current lighting.

  On the other hand, in the present invention, instead of essentially not enclosing mercury, a predetermined second halide is encapsulated in the previous period, and the color between the electrodes is configured in spite of the configuration of direct current lighting. The difference in temperature is small and can be used practically. This is because the second halide hardly emits light in the visible range, and therefore the metal of the first halide emits light strongly even on the anode side.

  In addition, a lighting device in which a metal halide discharge lamp is digitized is used in a headlight of a moving body such as an automobile and a lamp for a liquid crystal projector. In the case of alternating current lighting, the direct current or commercial frequency of the battery power supply is used. In general, a direct current obtained by rectifying the alternating current is converted into a high frequency alternating current and then supplied to a metal halide discharge lamp.

  On the other hand, in this invention, since it is the structure for direct current lighting, it is not necessary to convert into high frequency alternating current. For this reason, the circuit configuration of the electronic lighting device can be simplified, and a small, lightweight, and inexpensive lighting device can be used.

  In the present invention, the rising characteristics of the luminous flux can be improved by setting the pressure of the rare gas to 1 atm or more. Therefore, it is suitable for a headlamp.

  In summary, according to the present invention, a metal halide discharge lamp with few color separation problems even when lit with direct current can be provided by being configured to be lit with direct current.

  In the present invention, since mercury is not essentially enclosed, it is the light emission of the light emitting metal constituting the first halide that contributes mainly to light emission. Thus, even when the input to the lamp is changed, dimming is possible because there is little change in the color temperature of light emission and color rendering.

  Further, in the present invention, since the change in lamp characteristics with respect to variations in the shape and dimensions of the metal halide discharge lamp is small, the variation in emission color is small.

  Furthermore, instant restart is easy in the present invention. This is because the vapor pressure of the second halide is clearly lower in most cases compared to mercury. Thereby, since the peak value of the starting pulse voltage applied for restarting can be reduced, the dielectric strength of the lighting device, the starting device, the wiring, and the lighting fixture can be reduced and made inexpensive.

  Furthermore, in the present invention, the vapor pressure during lighting does not become extremely high, and it is easy to reduce it to about 60% at the time of mercury filling, so that the bursting during lighting of the hermetic container is reduced.

  Furthermore, the light emission efficiency of the metal halide discharge lamp of the present invention can be made comparable to that of a conventional metal halide discharge lamp enclosing mercury, and in addition, the color rendering can be slightly improved.

  As described above, in the present invention, the steady-state characteristics can be made substantially equal to that of the prior art regardless of whether the arc type is a short arc type or a long arc type.

  Moreover, according to the present invention, the lamp power is in a wide range of several tens of watts to several kW.

  In the present invention, a single tube type that lights up when the airtight container is exposed to the outside air may be used, or a double tube type that lights up when the airtight container is sealed in the outer tube. There is an effect of the period. Furthermore, the inside of the outer tube can be evacuated to reduce heat loss and further improve the light emission efficiency.

  However, in the case where the present invention is applied to a short arc type metal halide discharge lamp, the condensing efficiency can be increased if the arc is restricted as described above, and combined with a liquid crystal projector and a reflecting mirror. Even when used in an optical system of a reflecting mirror such as a headlight of a moving body such as an automobile used, an illumination device for shops, and an optical fiber illumination device, the illuminance on the irradiated surface can be significantly improved.

  [Modes Allowed in Implementation] The metal halide discharge lamp of the present invention is allowed to adopt the following modes in implementation.

    (First Aspect) The first aspect has the following configuration. That is, a fireproof and translucent airtight container, a pair of electrodes sealed in the airtight container, a first halide, a second halide, and a rare gas are enclosed in the airtight container, and the first The halide is one or more halides selected from the group consisting of sodium Na, scandium Sc and rare earth metals, and the second halide has a high vapor pressure and mainly determines the lamp voltage. And a discharge medium that is a metal halide, which is essentially not sealed with mercury.

  In this embodiment, the first halide is specified in the metal halide range suitable for various general uses from the viewpoints of light emission efficiency and color rendering properties. A metal halide discharge lamp can be constituted by using any one or plural kinds within the range of the first halide. The second halide has a high vapor pressure as in the present invention and mainly determines the lamp voltage. The second halide is also a metal halide that hardly emits light in the visible region as compared with the metal of the first halide.

  In the first aspect, it is possible to improve the luminous flux rising characteristics by setting the pressure of the rare gas to 1 atm or more.

  Thus, according to the first aspect, the metal constituting the first halide is selected from the group consisting of sodium, scandium, and a rare earth metal, and is generally used in terms of luminous efficiency and color rendering. A metal halide discharge lamp suitable for various applications can be provided.

  Further, by not using mercury, that is, essentially not containing mercury (hereinafter the same), the above-described operations and effects of the present invention are exhibited.

    (Second Aspect) The second aspect has the following configuration. That is, the discharge medium contains a halide of cesium Cs, and a combination with the present invention or the first aspect is allowed.

  In the second aspect, since the halide of cesium Cs is sealed as the third halide, the temperature distribution of the arc becomes flat as in the case of sealing mercury and the temperature gradient becomes small. , The heat loss of the arc tube is reduced. Therefore, the luminous efficiency is improved as compared with the case where no cesium halide is encapsulated, which is closer to the case where mercury is encapsulated.

  Further details are as follows. In other words, cesium halide produced by decomposition of cesium halide in the arc has a low ionization voltage and is ionized even in the “medium temperature portion of the arc”, which is a relatively low temperature area in the arc, releasing electrons. Cheap. For this reason, the presence of cesium in the arc increases the electron concentration in the medium temperature portion of the arc.

Incidentally, the electrical conductivity (σ) is proportional to the electron density. The energy input at a certain temperature portion is σE ² when the electric field strength is E. Therefore, the greater the electric conductivity (σ), in other words, the greater the electron density.

  Therefore, when cesium halide is encapsulated, the energy input in the medium temperature region in the arc increases, and as a result, the temperature in the medium temperature region in the arc increases.

  On the other hand, since all the inputs to the metal halide discharge lamp are constant, the temperature of the high temperature portion of the arc relatively decreases due to energy balance.

  For the above reasons, the temperature distribution of the arc becomes flat as in the case where mercury is enclosed, and the temperature gradient becomes small.

  On the other hand, in a conventional metal halide discharge lamp encapsulating mercury, mercury also emits light, but mercury itself does not have high luminous efficiency as described above. On the other hand, in the second embodiment, mercury is essentially not enclosed, and therefore a metal halide having high luminous efficiency can be obtained by using a light emitting metal having higher luminous efficiency than mercury, such as scandium Sc or sodium Na. A discharge lamp can be realized.

  Summarizing the above, according to the second aspect, by providing a cesium halide, a metal halide discharge lamp having a flat arc temperature distribution, a reduced heat loss, and an improved luminous efficiency can be provided. it can.

  Further, by not using mercury, that is, essentially not containing mercury (hereinafter the same), the above-described functions and effects of the present invention are exhibited.

    (3rd aspect) A 3rd aspect is the following structure. That is, a fire-resistant and light-transmitting hermetic container, a pair of electrodes sealed in the hermetic container, and a first halide composed of at least a luminescent metal halide, the vapor pressure is high, and the lamp voltage is mainly determined. An arc tube including a discharge medium sealed in an airtight container containing a second halide composed of a metal halide and a rare gas; an outer tube containing the arc tube; and a loss of heat generated from the arc tube And a heat retaining means for reducing mercury, and essentially not containing mercury.

  This aspect is configured to improve the light emission efficiency by reducing heat loss by providing heat retaining means for reducing heat loss generated from the arc tube in the present invention or each of the above aspects.

  The heat retaining means may have any configuration as long as the loss of heat generated from the arc tube can be reduced. For example, the following configuration is allowed.

  By evacuating the inside of the outer tube, heat loss due to convection and conduction of heat generated from the arc tube is reduced, and the discharge medium is kept warm. In this case, the specific structure, shape, and constituent materials are not limited. In the present invention, the vacuum in the outer tube means that the pressure in the outer tube is 10 Torr or less.

  In addition, it reflects the heat rays radiated from the arc tube to the outside and returns them to the arc tube, and has a heat ray reflective / visible light transmissive film that transmits visible light, thereby reducing heat loss due to radiation and keeping the discharge medium warm. can do. The heat reflecting / visible light transmitting film is formed on a cylindrical body made of quartz glass or the like disposed between the arc tube and the outer tube, the inner surface, the outer surface, the inner or outer surface of the outer tube, or formed on the outer surface of the arc tube. be able to.

  Furthermore, it goes without saying that the above-mentioned heat retaining means can be combined appropriately.

  In the third aspect, the light beam rise characteristic can be improved by setting the pressure of the rare gas to 1 atm or more.

  Thus, in this embodiment, since the heat retaining means for reducing the heat loss generated from the arc tube is provided, the heat loss generated by the discharge inside the arc tube is small, so the heat loss of the arc tube is reduced. This reduces the luminous efficiency.

  In summary, according to the third aspect, a metal halide discharge lamp is provided which has a heat retaining means for reducing heat loss generated from the arc tube, thereby reducing heat loss and improving luminous efficiency. can do.

  Further, by not using mercury, the effects and effects of the present invention described above are exhibited.

    (4th aspect) A 4th aspect is the following structure. That is, a fireproof and translucent airtight container, a pair of electrodes sealed in the airtight container, a first halide, a second halide, and a rare gas are enclosed in the airtight container, and the first A halide comprising sodium Na and scandium Sc, and a second halide comprising a discharge medium that is a metal halide having a high vapor pressure and mainly determining a lamp voltage, Essentially, mercury is not enclosed and the rated lamp power is for a headlamp of 100 W or less.

  A metal halide discharge lamp with a rated lamp power of 100 W or less for a headlamp of a moving body such as an automobile has a feature that a distance between electrodes is small and a tube wall load is large.

  For this reason, in the case of a conventional metal halide discharge lamp in which mercury is enclosed, the mercury vapor pressure becomes a high pressure of 20 atmospheres or more in order to obtain a required lamp voltage as described above. Easily damaged.

  In addition, xenon is also sealed at a high pressure because it is necessary to improve the luminous flux rising characteristics, and the pressure is about 35 atm. For this reason, it is necessary to apply a starting pulse voltage having a high voltage and a large power in order to start the starting gas with dielectric breakdown. At the time of instantaneous restart, a higher starting pulse voltage is required. Therefore, the lighting circuit, the luminaire, and the wiring must have a dielectric strength grade that is appropriate, and is therefore expensive.

  Furthermore, the problem of luminous flux rise has been solved by high voltage encapsulation of xenon and the application of a high starting pulse voltage and the use of a means to flow a large current immediately after lighting and gradually reduce the current. Is bad. That is, xenon emits light first, followed by mercury. This mercury emission continues until 10 to 20 seconds later. Mercury emission is poor in color rendering and does not fall within the required white range.

  On the other hand, in this embodiment, since mercury is not sealed, the pressure can be set to about 60% of the conventional pressure, and the problem of breakage of the hermetic container and the problem of the starting pulse voltage are remarkably reduced.

  Further, by limiting the first halide to the group consisting of sodium Na and scandium Sc, it is possible to obtain light emission with extremely high luminous efficiency while being white light emission necessary as a headlamp.

  In the fourth aspect, the light beam rise characteristic can be improved by setting the pressure of the rare gas to 1 atm or more.

  In summary, according to the fourth aspect, the first halide is defined as sodium and scandium, and the rated lamp power is defined as 100 W or less, resulting in high luminous efficiency and white light. In addition, it is possible to provide a small metal halide discharge lamp that has good chromaticity rise characteristics and is suitable for a headlamp of a moving body such as an automobile.

  Furthermore, since the operation and effect of the present invention are achieved by not enclosing mercury, the configuration of the present invention is very suitable as a headlamp for a moving body.

    (5th aspect) A 5th aspect is the following structure. That is, the second halide is magnesium Mg, iron Fe, cobalt Co, chromium Cr, zinc Zn, nickel Ni, manganese Mn, aluminum Al, antimony Sb, beryllium Be, rhenium Re, gallium Ga, titanium Ti, zirconium. It is characterized by being a halide of one or more metals selected from the group consisting of Zr and hafnium Hf, and allows a combination with any one of the first to fourth embodiments.

  In this embodiment, a metal suitable as the second halide is specified.

  According to the fifth aspect, it is possible to provide a metal halide discharge lamp in which the metal forming the second halide that can be replaced with mercury is effectively defined.

    (Sixth Aspect) A sixth aspect has the following configuration. That is, the second halide is mainly characterized by one or more halides selected from the group consisting of iron Fe, zinc Zn, manganese Mn, aluminum Al and gallium Ga. The combination with the aspect as described in any one of 1st thru | or 6th is permitted.

  In this embodiment, the optimum metal is specified as the second halide. However, these metals are optimally used as main components, but from the group of magnesium Mg, cobalt Co, chromium Cr, nickel Ni, antimony Sb, beryllium Be, rhenium Re, titanium Ti, zirconium Zr and hafnium Hf. The lamp voltage can be further increased by adding one or more selected types as subcomponents.

  According to the sixth aspect, it is possible to provide a metal halide discharge lamp that defines a more effective metal for forming the second halide.

    (7th aspect) A 7th aspect is the following structure. That is, the second halide is sealed in an amount of 0.05 to 200 mg per 1 cc of the internal volume of the hermetic container, and is combined with the aspect of the present invention or any one of the first to sixth aspects. Is allowed.

  This embodiment specifies a range of generally applicable encapsulation amounts for the second halide. Depending on the halide to be encapsulated, the preferred range is narrower, but is acceptable if it is noted that it is the overall range.

  According to the 7th aspect, the metal halide discharge lamp which prescribed | regulated the effective range of the addition amount of the 2nd halide in addition can be provided.

    (Eighth Aspect) The eighth aspect has the following configuration. That is, the second halide is characterized in that 1 to 200 mg per 1 cc of the internal volume of the hermetic container is sealed in the fourth description.

  In this embodiment, the amount of the second halide that is suitable for the headlamp of the moving body is specified.

  According to the 8th aspect, the metal halide discharge lamp which prescribed | regulated the sealing amount of the 2nd halide effective in addition for the headlamps of a moving body can be provided.

    (9th aspect) A 9th aspect is the following structure. That is, in the present invention, the fourth aspect or the eighth aspect, the rare gas is sealed at a pressure of 1 to 15 atm.

  In this embodiment, a noble gas filling pressure suitable for a headlamp of a moving body is defined.

  According to the 9th aspect, the metal halide discharge lamp which prescribed | regulated the sealing pressure of the noble gas effective in addition for the headlamp of a moving body can be provided.

    (Tenth Aspect) A tenth aspect has the following configuration. That is, in the fourth, eighth or ninth aspect, the hermetic container is characterized in that the maximum diameter portion has an inner diameter of 3 to 10 mm and an outer diameter of 5 to 13 mm.

  In this aspect, the preferred dimensions of the hermetic container in the metal halide discharge lamp for the headlamp of the moving body are defined.

  According to the 10th aspect, the metal halide discharge lamp which prescribe | regulated the size of the airtight container effective in addition for the headlamp of a moving body can be provided.

    (Eleventh aspect) The eleventh aspect has the following configuration. That is, in the fourth or eighth to tenth aspects, the distance between the electrodes is 1 to 6 mm.

  In this aspect, a distance between the electrodes suitable for the headlamp of the moving body is defined. If the distance between the electrodes exceeds 6 mm, the light source is separated from the point light source and the light condensing action is reduced. The distance between the electrodes is more preferably 1 to 5 mm.

  According to the 11th aspect, the metal halide discharge lamp which prescribed | regulated the distance between electrodes which was effective as a headlamp of a mobile body in addition can be provided.

    (Twelfth Aspect) A twelfth aspect has the following configuration. That is, the fourth or eighth to eleventh aspects are characterized by being configured to be lit with direct current.

  This aspect provides a metal halide discharge lamp that can be reduced in size, weight, and cost for a headlamp of a moving body by direct current lighting. In other words, as described above, a moving body such as an automobile is generally equipped with a battery power source. Therefore, it is lighter to use direct current than to convert a direct current to alternating current and then supply it to a metal halide discharge lamp. The circuit configuration of the device is simplified. Even when a control means such as a step-up chopper or a step-down chopper is used to set the direct current to a desired voltage, the above effect is unchanged. This is because the control means is used when necessary even in the case of AC lighting.

  The reason why direct current lighting is possible in this way is that the color separation becomes practically acceptable without enclosing mercury.

  According to the twelfth aspect, a metal halide discharge lamp that can be made small, light, and inexpensive for a headlamp of a moving body can be provided by being configured to be lit with direct current.

    (13th aspect) A 12th aspect is the following structure. That is, in the fourth or eighth to twelfth aspects, the discharge medium includes a cesium halide.

  This aspect is a metal halide discharge lamp for a moving body headlamp, in which a cesium halide is enclosed so that the gradient of the arc is flattened to improve luminous efficiency. It can be made higher than those encapsulating mercury.

  According to the thirteenth aspect, a metal halide discharge lamp with high luminous efficiency can be provided as a headlamp for a moving body by additionally enclosing a cesium halide.

    (14th aspect) The 14th aspect is the following structure. That is, the fourth or eighth to thirteenth aspect is characterized in that an airtight container is accommodated and an outer tube whose inside is maintained in a vacuum is provided.

  In this aspect, in the metal halide discharge lamp for the headlamp of the moving body, the hermetic container is housed in a vacuum outer tube to reduce the heat loss of the hermetic container, thereby improving the luminous efficiency. Thus, the luminous efficiency can be further increased as compared with the conventional mercury-encapsulated one.

  According to the fourteenth aspect, a metal halide discharge lamp with high luminous efficiency can be provided as a headlamp for a moving body by additionally storing the arc tube in an outer tube whose inside is evacuated.

    (15th aspect) The 15th aspect is the following structure. That is, the fourth or eighth to fourteenth aspects are characterized by comprising ultraviolet removing means for substantially removing ultraviolet rays from the light led out to the outside.

  “Substantially remove ultraviolet rays” means that the amount of ultraviolet rays is practically removed to an allowable range, and the ultraviolet rays must not be completely cut off by 100%. .

  The ultraviolet ray removing means may have any structure as long as ultraviolet rays are substantially removed. For example, the arc tube is housed in an outer tube made of a glass material having a composition having an ultraviolet cut performance. The inside of the outer tube may be communicated with the outside air, may be airtight, and the inside may be evacuated.

  Moreover, you may provide an ultraviolet-ray removal performance to the inner surface of the arc tube or itself. By replacing the material structure on the inner or outer surface of the arc tube with an ultraviolet blocking tissue or by depositing a film of an ultraviolet blocking light-transmitting material, ultraviolet blocking performance can be imparted.

  Further, an ultraviolet blocking cylinder may be provided outside the arc tube.

  Thus, in this embodiment, the ultraviolet light led out to the outside is substantially removed, so that the headlamp is deteriorated by the ultraviolet light and the human eye is prevented from being irradiated with the ultraviolet light.

  Further, when an outer tube is used, the hermetic container can be mechanically protected by the outer tube.

  Summarizing the above, according to the fifteenth aspect, the provision of the outer tube having an ultraviolet ray cutting performance provides a metal halide discharge lamp that does not deteriorate the headlamp and does not emit ultraviolet rays. .

    The metal halide discharge lamp DC lighting device of the present invention is characterized by comprising the metal halide discharge lamp of the present invention; and an electronic DC lighting device for lighting the metal halide discharge lamp.

  The above-described metal halide discharge lamp DC lighting device of the present invention is a metal halide discharge lamp lighting suitable for direct-current lighting of the metal halide discharge lamp of the present invention so as to obtain electric characteristics and light emission characteristics substantially equivalent to those of the prior art in which mercury is enclosed. Specifies the device. Here, “substantially” means that there is a difference that is somewhat inferior within a practical range as compared with the prior art. In view of the fact that this type of metal halide discharge lamp may be lit by an electronic lighting device, it is in a practically acceptable range.

  Thus, according to the present invention, there is provided a metal halide discharge lamp DC lighting device for lighting the metal halide discharge lamp of the present invention so as to obtain approximately the same electrical characteristics and light emission characteristics as a conventional metal halide discharge lamp enclosing mercury. can do.

  In implementing the metal halide discharge lamp DC lighting device of the present invention described above, it is allowed to adopt the following mode.

  That is, the present invention relates to a metal halide discharge lamp according to the present invention, the metal halide discharge lamp according to any one of the fourth, seventh, or eighth to fourteenth aspects; three times the rated lamp current immediately after the metal halide discharge lamp is turned on. An electronic DC lighting circuit configured to supply the above current and reduce the current with the passage of time.

  The first aspect defines a metal halide discharge lamp lighting device that satisfies the luminous flux rising characteristics required for a headlamp of a moving body.

  The lighting circuit is configured to operate with a direct current.

  The lighting circuit may have any circuit configuration as long as it has the above-described configuration.

  Thus, according to this aspect, by providing a lighting circuit that allows a current more than three times the rated lamp current to flow immediately after lighting and gradually reduces the current as time passes, the instantaneous luminous flux rise characteristic and instantaneous chromaticity are provided. It is possible to provide a metal halide discharge lamp DC lighting device that has a good rise and is suitable for use as a headlamp for a moving object.

    An illuminating device of the present invention comprises: an illuminating device main body; the present invention or first to fourteenth metal halide discharge lamps supported by the illuminating device main body; and an electronic direct current lighting device for lighting the metal halide discharge lamp. It is characterized by being.

  The present invention is applicable to all apparatuses using the present invention or the first to fourteenth metal halide discharge lamps for some illumination purposes. In the case of the short arc type, particularly an illumination device used in combination with an optical system such as a reflector and / or a lens, such as a liquid crystal projector, an overhead projector, a headlight of a moving object such as an automobile, an optical fiber illumination device, a spotlight, etc. It is suitable for store lighting equipment and the like. In addition, the metal halide discharge lamp of this invention is the meaning containing the metal halide discharge lamp of said each aspect.

  In the case of the long arc type, it can be used for various lighting fixtures for general lighting, such as downlights, direct ceiling lights, road lighting fixtures, tunnel lighting fixtures and floodlights, and display devices. .

  The electronic DC lighting device may have any configuration as long as the metal halide discharge lamp of the present invention is DC-lit.

    According to the present invention, since one or more halides selected from the group consisting of sodium Na, scandium Sc, and rare earth metal are encapsulated as the first halide, the metal of the first halide is It mainly emits visible light, and as the second halide, magnesium Mg, iron Fe, cobalt Co, chromium Cr, zinc Zn, nickel Ni, manganese Mn, aluminum Al, antimony Sb, beryllium Be, rhenium Re, gallium Ga, Since the halide of one or more metals selected from the group consisting of titanium Ti, zirconium Zr and hafnium Hf is encapsulated, the second halide mainly determines the lamp voltage. Enclose mercury without essentially using heavy mercury. Which has substantially the same electrical characteristics and light emission characteristics as a metal halide discharge lamp, not only no color irregularities due to DC lighting, it is possible to provide a metal halide discharge lamp.

  In addition, according to the present invention, it is possible to provide a metal halide discharge lamp for direct current lighting that is small, lightweight, and inexpensive, and a metal halide discharge lamp direct current lighting device and an illumination device including the metal halide discharge lamp.

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

  [About Embodiment 1] Embodiment 1 is an example of a metal halide discharge lamp.

    FIG. 1 is a front view showing a metal halide discharge lamp according to a first embodiment for carrying out the present invention. In the figure, 1 is an airtight container, 2 is an electrode, 3 is a sealing metal foil, and 4 is an external lead wire.

  The airtight container 1 is formed by forming quartz glass into a rotating ellipsoidal shape having an inner diameter of 14 mm, and is integrally provided with a pair of long and narrow sealing portions 1a and 1a at both ends in the major axis direction of the ellipse.

  The electrode 2 is formed by winding an electrode coil 2b with the electrode shaft 2a and the tip of the electrode shaft 2a protruding slightly. The base portion of the electrode shaft 2a is welded to one end of the sealing metal foil 3 in the sealing portion 1a. The distance between the electrodes is set to 4 mm.

  The sealing metal foil 3 is made of molybdenum foil, and is hermetically sealed in the sealing portion 1a, and the external lead wire 4 is welded to the other end.

  In the hermetic vessel 1, a rare gas, a first halide, and a second halide are sealed as a discharge medium.

  Argon 500 Torr was enclosed as a rare gas.

As a first halide, dysprosium iodide DyI ₃ 1mg, a neodymium iodide NdI ₃ and 1mg sealed.

  As the second halide, 8 mg of the halide shown in Table 1 was enclosed.

  The short arc type metal halide discharge lamp thus obtained was lit at a constant input power of 150 W, and the lamp voltage, luminous efficiency and color temperature were measured together with the conventional examples shown below.

  The conventional example has the same specifications as the present embodiment except that 13 mg of mercury is enclosed instead of the second halide.

[Table 2]
Lamp Second Halide Lamp Voltage Luminous Efficiency Color Temperature Screen Illuminance Ratio
(V) (lm / W) (K)
1 (conventional example)-75 71 8700 1.0
2 AlI ₃ 62 72 9120 1.4
3 FeI ₂ 70 70 9210 1.35
4 ZnI ₂ 73 68 9160 1.42
5 SbI ₃ 63 73 8930 1.35
6 MnI ₂ 55 72 9040 1.42
7 CrI ₂ 58 69 9100 1.45
8 GaI ₃ 59 68 9030 1.39
9 ReI3 61 70 9240 1.37
10 TiI ₄ 72 70 9220 1.38


From Table 2, in this embodiment, a metal halide discharge lamp having a lamp voltage of 50 V or more, luminous efficiency and color temperature similar to those of the conventional example was obtained.

  Next, the above-mentioned discharge lamp was combined with the optical system shown in FIG. 2 to measure the screen illuminance ratio, and the results are also shown in Table 2.

FIG. 2 is a conceptual explanatory diagram of an optical system of an RGB color separation type liquid crystal projector. In the figure, the metal halide discharge lamp shown in FIG. 1 5, 6 reflector, the UV-IR cut filter 7, 8a, 8b are color separation dichroic _{mirrors, 9 B, 9 G, 9} R liquid crystal panel, 10a, 10b Are mirrors, 11a and 11b are color combining mirrors, 12 is a projection lens, B is a blue optical axis, G is a green optical axis, and R is a red optical axis.

The liquid crystal panel 9 _B blue, 9 _G is green, 9 _R is driven by each of the image signals of red.

  As is clear from Table 2, according to the metal halide discharge lamp of this embodiment, a screen illuminance about 1.4 times that of the conventional example was obtained.

  Next, the results of measuring the arc temperature distribution of the metal halide discharge lamp of this embodiment and the conventional example will be described with reference to FIG.

    FIG. 3 is a graph showing the arc temperature distribution of lamp 2 (this embodiment) and lamp 1 (conventional example) in Table 1. In the figure, the horizontal axis indicates the radial position in the central section between the electrodes of the hermetic container, and the vertical axis indicates the arc temperature (K). Curve A is the arc temperature distribution curve of the lamp 2 of this embodiment, and curve B is the arc temperature distribution curve of the conventional example.

  From the figure, it can be seen that the arc of the metal halide discharge lamp of this embodiment is restricted.

  Further, Table 3 shows the results of measuring the color temperature when the lamps 2 and 3 (this embodiment) and the lamp 1 (conventional example) in Table 2 are lit at input powers of 70 W, 90 W, 110 W and 130 W.

[Table 3]
Lamp 70W 90W 110W 130W
1 (conventional example) 6510K 6930K 7560K 8030K
2 8630K 8740K 8900K 9060K
3 8720K 8860K 9030K 9180K

As described above, in the lamp 1 (conventional example), when the input is reduced, light emission due to mercury becomes relatively dominant, so that the color temperature is remarkably lowered.

  However, in the lamps 2 and 3 (this embodiment), mercury is not essentially enclosed, and visible light emission by the second halide is small. Main light emission. The color separation temperature at which the vapor pressure of the luminescent metal decreases as the input decreases is slightly decreased.

  In the above case, when the power was changed from 150 W (see Table 2) to 70 W (see Table 3), the conventional example changed by 2190K.

  On the other hand, in this embodiment, the change was 500 K or less.

  Next, Table 4 shows the results of evaluation on restart.

[Table 4]
Lamp restart voltage (kV)
1 (conventional example) 12
2 4
3 3
4 5
5 3
6 4
7 4
8 5
9 3
10 6

As shown in Table 4, in this embodiment, the restart voltage is low. This is because the vapor pressure during lighting of the second halide is lower than that of mercury, for example, in the case of the lamp 3, it is 0.6 atm, and other halides are at most within 5 atm.

  On the other hand, in the conventional example in which mercury is sealed, since it is 28 atm, the restart voltage is high as shown in Table 4.

    FIG. 4 is a partial sectional front view showing a projector lamp in which the metal halide discharge lamp in the first embodiment for carrying out the present invention is integrated with a reflecting mirror. In the figure, the same parts as those in FIG.

  In this embodiment, the metal halide discharge lamp 5 and the reflecting mirror 6 shown in FIG. 1 are integrated.

  Reference numeral 5b denotes a heat retaining film, which is formed on the outer surface of the hermetic container 1 surrounding the light projection opening side electrode of the reflecting mirror 6 in the metal halide discharge lamp 5.

  The reflecting mirror 6 has a rotating quadratic curved surface and is formed by glass molding. The reflecting mirror 6 has a neck portion 6a at the top and a visible light reflecting / infrared transmitting multilayer interference reflecting film on the inner surface of the reflecting mirror main body 6b. 6c is attached. In addition, a through hole 6d is formed in the reflecting mirror main body 6b.

  The metal halide discharge lamp 5 has its base 5 a fixed inside the neck portion 6 a via a base cement 7. Further, the feeder 8 passes through the through hole 6 d of the reflecting mirror 6 and is led out to the back side of the reflecting mirror 6.

  An electronic lighting device 9 supplies a required voltage and lamp current to the metal halide discharge lamp 5.

  [Embodiment 2] Embodiment 2 is an example of an illumination device using the metal halide discharge lamp of the present invention.

    FIG. 5 is a conceptual diagram showing a liquid crystal projector using the projector lamp shown in FIG. 4 as an example of an illumination device using the metal halide discharge lamp of the present invention. In the figure, the same parts as those in FIG. 11 is a liquid crystal display means, 12 is an image control means, 13 is an optical system, 14 is a main body case, and 15 is a screen.

  The liquid crystal display means 11 displays an image to be projected by liquid crystal, and is irradiated with illumination light emitted from the metal halide discharge lamp 5 from the back and condensed by the reflecting mirror 6.

  The image control means 12 drives and controls the liquid crystal display means 11, and can be provided with a television reception function if necessary.

  The main body case 14 houses the above elements.

  The optical system 13 projects the light that has passed through the liquid crystal display means 11 onto the screen 15.

  [About Embodiment 3] Embodiment 3 is another example of a metal halide discharge lamp.

    FIG. 6 is a central sectional front view showing a metal halide discharge lamp in a second embodiment for carrying out the present invention. In the figure, the same parts as those in FIG. This embodiment is different from the first embodiment shown in FIG. 1 in that the airtight container 1 is a small metal halide discharge lamp having an internal volume of 0.05 cc.

  The airtight container 1 has an inner diameter of 4 mm.

  The electrode 2 is not equipped with an electrode coil. The distance between the electrodes is 4.2 mm.

The discharge medium is as follows. Xenon 1 atm. The first halide was sealed with 0.14 mg of scandium iodide ScI ₃ and 0.86 mg of sodium iodide NaI. Further, 1 mg of the halide shown in Table 5 was sealed as the second halide.

  Then, the obtained metal halide discharge lamp is turned on at a constant input power of 35 W, and the lamp voltage, luminous efficiency, average color rendering index (hereinafter referred to as “color rendering property”) Ra and color temperature are shown below. Table 5 shows the results of measurement together with the conventional example.

  The conventional example has the same specifications as this embodiment except that 1 mg of mercury is enclosed instead of the second halide.

[Table 5]
Lamp Second halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 (conventional example)-83 80 63 4120K
2 AlI ₃ 62 78 65 3860K
3 FeI ₂ 70 73 71 4210K
4 ZnI ₂ 75 78 65 3830K
5 SbI ₃ 63 75 66 3790K
6 MnI ₃ 55 72 68 3950K
7 CrI ₂ 58 74 65 3860K
8 GaI ₃ 59 76 66 3760K
9 ReI ₃ 61 78 64 3840K

As is apparent from Table 5, in this embodiment, the lamp voltage was 50 V or more, and the luminous efficiency was slightly lower than that of the conventional example, but there was a tendency that the color rendering was improved.

  From the above, it can be evaluated that the present embodiment has substantially the same characteristics as the conventional example.

  Next, Table 6 shows the results of measuring the color rendering properties and the color temperature when the lamp 3 and the lamp 1 (conventional example) in Table 5 are lit at input powers of 15 W, 20 W, 25 W and 30 W.

[Table 6]
Lamp 15W 20W 25W 30W
1 (conventional example) color rendering (Ra) 40 45 58 61
Color temperature (K) 5640 4970 4630 4350
3 Color rendering (Ra) 63 64 66 69
Color temperature (K) 4530 4440 4310 4240

As shown in Table 6, in the conventional example of the lamp 1, when the input was changed from 35 W (see Table 5) to 15 W, the color temperature changed by 1520 K and the color rendering performance changed by 23. In this case, the change is too large and the light cannot be actually dimmed.

  On the other hand, in this embodiment, the change in color temperature is 320K, the change in color rendering is only 8, and sufficient light control is possible.

  Next, Table 7 shows the results of evaluation on restart.

  It should be noted that a discharge lamp having the same specifications as that of the lamp 3 is manufactured as the lamp 10 except that 100 Torr of xenon Xe is enclosed, and the result of measuring the restart voltage is also shown.

[Table 7]
Lamp restart voltage (kV)
1 (conventional example) 14
3 7
10 3

As shown in Table 7, in this embodiment, the restart voltage is halved compared to the conventional example. In particular, in the discharge lamp 10 in which the rare gas sealing pressure is lowered and the rise of the luminous flux is not emphasized, a significant improvement was observed.

    FIG. 7 is a graph showing the relationship between the rise time of the luminous flux and the sealed pressure of xenon Xe in the metal halide discharge lamp of the second embodiment for carrying out the present invention. In the figure, the horizontal axis represents the Xe sealing pressure (atmospheric pressure), and the vertical axis represents the luminous flux rise time (seconds).

  As is apparent from the figure, when the sealing pressure is 1 atm or more, the rise time of the light beam is remarkably shortened.

FIG. 8 is a graph showing the relationship of the lamp voltage with respect to the enclosed amount when iron iodide FeI ₂ is used as the second halide in the metal halide discharge lamp of the second embodiment. In the figure, the horizontal axis represents the amount of FeI ₂ enclosed (mg / cc), and the vertical axis represents the lamp voltage (V).

  According to the figure, it can be seen that the lamp voltage exceeds 30 V is 1 mg or more per 1 cc of the internal volume of the hermetic container.

In addition, when the internal volume of the airtight container is 200 mg or more per 1 cc, the non-evaporated FeI ₂ absorbs light, so that the luminous efficiency is lowered.

  [About Embodiment 4] Embodiment 4 is another example of the metal halide discharge lamp of the present invention.

    FIG. 9 is a front view showing a metal halide discharge lamp according to a third embodiment for carrying out the present invention. In this embodiment, a small short arc type metal halide discharge lamp similar to that shown in FIG. 6 is further mounted on a headlight of a moving body such as an automobile. 21 is an outer tube, 22 is a base, and 23 is an insulating tube.

  The outer tube 21 has an ultraviolet ray cutting performance and houses therein a metal halide discharge lamp 5 ′ having a structure similar to that shown in FIG. 6, and both ends thereof are fixed to the sealing portion 1a. It is not airtight but communicates with the outside air. One sealing portion 1 a is planted in the base 22. The external lead wire 4 led out from the other end extends in parallel to the outer tube 21 and is introduced into the base 22 and is connected to a terminal (not shown).

  The insulating tube 23 covers the external lead wire.

  [About Embodiment 5] Embodiment 5 is another example of a lighting device using the metal halide discharge lamp of the present invention.

    FIG. 10 is a perspective view showing a headlamp for a moving body such as an automobile as another example of an illuminating device using the metal halide discharge lamp of the present invention. In the figure, 31 is a reflecting mirror and 32 is a front cover.

  The reflecting mirror 31 is formed into a deformed paraboloid by molding plastics, and is configured to attach and detach a metal halide discharge lamp (not shown) shown in FIG. 9 from the back of the top.

  The front cover 32 is integrally formed with prisms or lenses by molding transparent plastics, and is airtightly attached to the front opening of the reflecting mirror.

  [About Embodiment 6] Embodiment 6 is another example of the metal halide discharge lamp of the present invention.

    FIG. 11 is a front view showing a metal halide discharge lamp according to a fourth embodiment for carrying out the present invention. In the figure, 41 is an arc tube, 42 is a first support band, 43 is a first conductor frame, 44 is a flare stem, 45 is a bimetal and starting resistor, 46 is a second support band, and 47 is a second conductor. A frame, 48 is a conducting wire, 49 is an outer tube, and 50 is a base.

  The arc tube 41 is set to a distance of 42 mm between electrodes by sealing a pair of main electrodes and one auxiliary electrode close to one main electrode at both ends of an elongated quartz glass tube having an inner diameter of 20 mm. Yes.

  The first support band 42 is fixed to the first conductor frame 43 by holding an upper pinch seal portion in the figure of the arc tube 41.

  The first conductor frame 43 is fixed to the flare stem 44 and applies a voltage to the main electrode above the arc tube 41.

  The flare stem 44 is sealed to the neck portion of the outer tube 49.

  The bimetal and the starting resistor 45 form a starting circuit, and apply a voltage having a polarity opposite to that of the main electrode adjacent to the starting auxiliary electrode at the time of starting.

  The second support band 46 is fixed to the second conductor frame 47 by holding a lower pinch seal portion in the figure of the arc tube 41.

  The second conductor frame 47 is fixed to the top portion of the outer tube 49.

  The conducting wire 48 has one end connected to the lead wire of the flare stem 44, the other end connected to the second support band 46, and connected to the other main electrode of the arc tube 41 through the second conductor frame 47. ing.

  The outer tube 49 encloses the arc tube 41, the bimetal, and the starting resistor 45 in the above configuration. Although not shown, an initial getter is attached to adsorb the impure gas inside.

By the way, in the arc tube 41, ₃ mg of scandium iodide ScI ₃ and 15 mg of sodium iodide NaI were sealed as the first halide. Fifteen types of metal halide discharge lamps were produced in which 20 mg of the halide shown in Table 8 was sealed as the second halide, and 20 Torr of argon was sealed as the noble gas. Among these lamps, the lamp 14 is obtained by adding 5 mg of ZnI ₂ in addition to the specifications of the lamp 2. The lamp 15 is obtained by adding 5 mg of FeI ₂ in addition to the specifications of the lamp 10. All of them are intended to increase the lamp voltage by using a plurality of second halides.

  For comparison, a metal halide discharge lamp having the same specifications as in this embodiment was manufactured except that 40 mg of mercury was enclosed instead of the second halide as a conventional example.

  Table 8 shows the results of measuring the lamp voltage, luminous efficiency, color temperature, and color rendering properties together with the conventional example by lighting at a constant lamp input of 400 W for this embodiment and the conventional example.

[Table 8]
Lamp Second halide Lamp voltage Luminous efficiency Color temperature Color rendering
(V) (lm / W) (K) (Ra)
1 (conventional example)-132 101 4320 62
2 AlI ₃ 112 96 4120 65
3 FeI ₂ 118 95 4510 68
4 ZnI ₂ 120 98 4160 65
5 SbI ₃ 114 94 4040 69
6 MnI ₂ 83 93 4210 64
7 CrI ₂ 109 96 4260 68
8 GaI ₃ 125 97 4130 67
9 ReI ₃ 103 91 4240 69
10 MgI ₂ 78 95 4140 66
11 CoI ₂ 118 95 4480 68
12 NiI ₂ 109 95 4410 69
13 BeI ₂ 95 93 4210 63
14 AlI ₃ + ZnI ₂ 137 97 4150 65
15 MgI ₂ + FeI ₂ 105 95 4210 67

The electrical characteristics in the above embodiment will be described.

  As is apparent from Table 8, the lamp voltage in the conventional example is determined by the amount of mercury enclosed.

On the other hand, the lamp voltage of this embodiment is mainly governed by the evaporation amount of the second halide. In this case, if a heat retaining means is provided in the arc tube 41, for example, even in the case where the iron iodide FeI ₂ of the lamp 3 is sealed, an evaporation amount necessary to exhibit a required lamp voltage can be obtained.

  Therefore, the lamp voltage similar to that of the conventional example can be obtained by appropriately setting the degree of heat retention of the arc tube 41.

  Next, the light emission characteristics will be described.

  In the lamp 3, light emission of iron Fe, which is a metal of the second halide, is slightly seen in the visible range, but light emission of mercury is lost.

  Luminous efficiency is slightly reduced, but color rendering is slightly increased. In addition, it was found that when the iron Fe halide alone was encapsulated, strong ultraviolet radiation was emitted, but by encapsulating it together with the first halide, strong ultraviolet radiation was greatly attenuated. Furthermore, the emission of ultraviolet rays can be reduced by using a mixture with another second halide.

  As described above, even in a long arc type metal halide discharge lamp, the electric characteristics and light emission characteristics of the lamp can be made equivalent to those of the prior art in which mercury is sealed without using mercury with a large environmental load. confirmed.

  Further, as seen in the lamp 15 and the lamp 16, it was confirmed that the lamp voltage was adjusted to the same level as that of mercury by using a plurality of metals as the second halide.

  Next, Table 9 shows changes in color rendering properties and color temperatures when a metal halide discharge lamp having the same structure as that of the fourth embodiment of the present invention is lit at lamp powers of 350 W, 300 W, 250 W and 200 W, as compared with the conventional example. . In addition, the number of the term of a lamp shows the same lamp as the same number of Table 8.

[Table 9]
Lamp 200W 250W 300W 350W
1 Color rendering (Ra) 38 46 54 60
(Conventional example) Color temperature (K) 6010 5630 5160 4530
2 Color rendering (Ra) 60 61 62 64
Color temperature (K) 4560 4450 4220 4100

As is apparent from Table 9, in the conventional example, as the lamp power is reduced, the color temperature is remarkably increased and the color rendering properties are greatly reduced.

  On the other hand, the lamp 2 of this embodiment has very little change in both color rendering properties and color temperature.

  From the above, according to the present embodiment, it was confirmed that the color rendering was possible because the color rendering properties and the color temperature hardly changed even when the lamp power was changed.

    FIG. 12 is a graph showing the spectral distribution of a conventional long arc metal halide discharge lamp. In the figure, the horizontal axis represents wavelength (nm), and the vertical axis represents relative radiation power (%).

  This metal halide discharge lamp is the lamp 1 in Table 8, and the main emission line spectrum is attached with an arrow and a chemical symbol of an element emitted thereon. That is, the light emission of this lamp is mainly composed of light emission of scandium Sc, sodium Na and mercury Hg.

Thus, when the lamp input is reduced, the vapor pressure of scandium iodide ScI ₃ and sodium iodide NaI is low, so the amount of evaporation decreases.

  On the other hand, since mercury has a high vapor pressure, even if the lamp input is reduced to 200 W, for example, all is evaporated. That is, when the lamp power is reduced, light emission by mercury is relatively dominant and the color temperature is increased. As described above, in the conventional example, when the lamp power is changed to adjust the light, a large change in the color temperature occurs.

  On the other hand, in the fourth embodiment, when the lamp power is reduced, sodium Na and scandium Sc decrease at the same rate. In addition, since the second halide emits little light in the visible range, it hardly affects the light emission characteristics of the metal halide discharge lamp. Therefore, in the above embodiment, even if the lamp power is reduced, the change in the color temperature is small. Returning to Table 8 and Table 9 again, when the lamp power is changed from 400 W to 200 W, the color temperature changes by 1690 K in the conventional example, but only changes by 440 K in the fourth embodiment. It was.

  [About Embodiment 7] Embodiment 7 is another cold of the metal halide discharge lamp of the present invention.

    FIG. 13: is a principal part cross-sectional front view which shows the metal halide discharge lamp in the 5th form for implementing this invention. In the figure, 51 is an airtight container, 52 is an electrode, 53 is a heat retaining means, 54 is an outer tube, 55 is a support band, 56 is a base, and 57 is an introduction line.

  The airtight container 51 is made of quartz glass and has an inner diameter of 12 mm. Pinch seal portions 51 a are formed at both ends of the airtight container 51.

  The electrode 52 is positioned at the center of the portion that is reduced in diameter at both ends in the hermetic container 51, and the base end is embedded in the pinch seal part 51 a, so that the electrode 52 is fixed to the hermetic container 51. The distance is set to 17 mm.

  The heat retaining means 53 is disposed on the outer surface of the portion surrounding the electrode of the airtight container 51.

  The outer tube 54 is formed by sealing both ends of a quartz glass cylindrical body with a pinch seal portion 54a, and the airtight container 51 is formed through a support band 55, 55 while forming a relatively narrow gap inside. Stored.

  The base 56 is attached to the pinch seal portions 54 a at both ends of the outer tube 54 with a base cement.

  The introduction line 57 connects between the pinch seal portion 54 a of the outer tube 54 and the pinch seal portion 51 a of the airtight container 51.

By the way, in the airtight container 51, 1.5 mg of scandium iodide ScI ₃ as a first halide, 7.5 mg of sodium iodide NaI, and 20 Torr of argon as a rare gas are sealed. A metal halide discharge lamp in which 5 mg of each of the halides 2 was enclosed was produced.

  For comparison, a metal halide discharge lamp having the same specifications as that of the embodiment except that 12.5 mg of mercury was sealed instead of the second halide as a conventional example listed in the lamp 1 of Table 10.

  Table 10 shows the results of measuring the lamp voltage, the luminous efficiency, the color temperature, and the average color rendering index Ra by lighting each manufactured lamp with a lamp input of 100 W.

[Table 10]
Lamp Second halide Lamp voltage Luminous efficiency Color temperature Color rendering
(V) (m / W) (K) (Ra)
1 (conventional example)-122 71 4120 61
2 AlI ₃ 112 67 4140 65
3 FeI ₂ 110 66 4480 67
4 ZnI ₂ 111 68 4160 64
5 SbI ₃ 106 63 4140 68
6 MnI ₂ 80 66 4250 64
7 CrI ₂ 109 66 4230 68
8 GaI ₃ 115 67 4180 67
9 CoI ₂ 110 65 4380 66
10 NiI ₂ 105 65 4460 68

As is apparent from Table 10, it was confirmed that even in this embodiment, even if mercury is not used, both the electrical characteristics and the light emission characteristics can be equivalent to those of a lamp enclosing mercury.

  Next, in the above embodiment, the pressure during operation of the lamp will be described with reference to the lamp 1 and the lamp 2 in comparison.

The pressure during operation of the lamp 1 depends on the amount of mercury (in moles), and the pressure of the lamp 2 depends on the amount of aluminum iodide AlI ₃ in a proportional relationship.

  From the viewpoint of the number of moles, the lamp 1 and the lamp 2 are approximately 5: 1, and the pressure during lighting is also 5: 1. Since the estimated pressure of the lamp 1 is about 15 atmospheres, the lamp 2 is about 3 atmospheres.

  The metal halide discharge lamp has a problem that the quartz glass becomes brittle due to the reaction between the quartz glass, which is the arc tube material, and the halide during long-term lighting, and therefore cannot burst the pressure in the arc tube.

  As can be understood from the above, in the present invention, mercury is not essentially enclosed, so that the pressure during lighting is low, so the risk of explosion is greatly reduced.

  Further, in the above-described embodiment, an experiment using the lamp 1 and the lamp 2 was performed with respect to the rise of the spectral characteristics, which will be described with reference to the results.

  In the experiment, a lighting circuit was used in which the rise of the luminous flux was 100% 8 seconds after the switch was turned on. Then, the spectral distribution in the visible region of the lamp 1 and the lamp 2 was measured every second after the switch was turned on, and the chromaticity coordinates at each time point were calculated based on the result.

    FIG. 14 is a chromaticity diagram showing the rise of spectral characteristics of the metal halide discharge lamp in the fifth embodiment for carrying out the present invention in comparison with the conventional example. In the figure, the horizontal axis indicates the x coordinate of the chromaticity coordinate, the vertical axis indicates the same y coordinate, and the coordinate area surrounded by a frame is the white color of the automotive headlamp defined by Japanese Industrial Standards (JIS). Indicates the area. In the figure, curve C shows the rise of the spectral characteristics of this embodiment, and curve D shows the rise of the spectral characteristics of the conventional example. In addition, the number attached | subjected beside the measured value of each curve represents the elapsed time after switch-on in second.

  In the case of the conventional example, since only mercury is emitted at the beginning, the spectral characteristics are poor as shown by the curve D, which is outside the white region defined by JIS, and it takes about 1 minute to enter the white region.

  On the other hand, in the case of this embodiment, sodium Na and scandium Sc are emitted from the beginning, so that they are in the white region.

  Therefore, the present embodiment shows that the present invention is suitable for applications where both the rising of the luminous flux after switching on and the rising of the spectral characteristics are required early.

  [About Embodiment 8] Embodiment 8 is another example of the metal halide discharge lamp of the present invention.

    FIG. 15: is a principal part cross-sectional front view which shows the metal halide discharge lamp in the 6th form for implementing this invention. In the figure, 61 is an airtight container, 62 is an electrode, 63 is a base, and 64 is an external lead wire.

  The hermetic container 61 is a spheroidal sphere made of quartz glass, has a maximum inner diameter of 32 mm, and has elongated sealing portions 61a extending from both ends thereof. And in the sealing part 6a, it is comprised so that an electric current may be introduce | transduced with respect to the electrode 62, sealing the airtight container 61 via the sealing metal foil which consists of molybdenum.

  The electrode 62 includes an electrode shaft 62a and a coil 62b, and a base end portion of the electrode shaft 62a is embedded and supported in the sealing portion 61a. The distance between the electrodes is 30 mm.

  The base 63 is attached to the end of the sealing portion 61a with a base cement, and the external lead wire 64 is led out from a through hole formed in the center.

  The external lead wire 64 is covered with an insulating coating and has a connection terminal 64a at the tip.

Incidentally, the airtight container 61 bromide dysprosium DyBr ₃ as a first halide, 4 mg bromide holmium HOBr ₃ and thulium bromide TMBR ₃ respectively, the argon while 100Torr sealed as the rare gas, the second halide As shown in Table 11, metal halide discharge lamps each containing 30 mg of a halide shown in Table 11 were produced.

  For comparison, as a conventional example, a metal halide discharge lamp having the same specifications as this embodiment, except that 4 mg of the same material as the first embodiment is used as the first halide and 90 mg of mercury is enclosed instead of the second halide. Was made.

  Table 11 shows the results of measuring the lamp voltage, the light emission efficiency, the color temperature, and the average color rendering index Ra together with the conventional example by lighting the obtained metal halide discharge lamp with a constant input of 2 kW.

[Table 11]
Lamp Second halide Lamp voltage Luminous efficiency Color temperature Color rendering
(V) (lm / W) (K) (Ra)
1 (conventional example)-116 94 5120 91
2 AlI ₃ 104 92 5020 92
3 FeI ₂ 107 93 5220 90
4 ZnI ₂ 112 92 5340 92
5 SbI ₃ 106 89 5080 92
6 CrI ₂ 109 90 5020 91
7 GaI ₃ 115 90 5220 89
8 ZrI ₄ 116 88 5430 93

As is apparent from Table 11, it was confirmed that a metal halide discharge lamp substantially equivalent to the conventional example in which mercury is sealed in both the electrical characteristics and the light emission characteristics can also be obtained in this embodiment.

The lighting pressure in this embodiment will be described. The lamp 1 and the lamp 2 in Table 11 are compared. Since the pressure of the lamp 1 depends on the proportion of mercury (mole number) and the pressure of the lamp 2 depends on the amount of aluminum iodide AlI ₃ , the number of moles of the lamp 1 and the lamp 2 is 6 : 1 so that the pressure during operation of the lamp 2 is 1/6 that of the lamp 1. Since the estimated pressure during lighting of the lamp 1 is 12 atmospheres, the lamp 2 is about 2 atmospheres.

  By the way, since the metal halide discharge lamp of this embodiment is designed so that it can be used by being mounted on a projector, in order to make the projector as compact as possible, the lamp is also made compact. Therefore, the tube wall load is high and the temperature during operation of the arc tube is also high. In such a high-load metal halide discharge lamp, the reaction between the quartz glass, which is the arc tube material, and the halide is active during long-term lighting, so that the quartz glass becomes brittle and cannot withstand the pressure in the arc tube. There is a problem that it may burst.

  However, in this embodiment, since the pressure during lighting is small, the risk of explosion is significantly reduced.

  Moreover, although said projector is used in a sports stadium, instantaneous restart is requested | required in such an application. A high-voltage pulse voltage is applied at the time of instantaneous restart. The lamp 1 requires a pulse voltage of 35 kV, but in this embodiment, since the pressure during lighting is low in any of the lamps 2 to 8, an instantaneous restart is possible by applying a pulse voltage of 8 kV or less. there were.

  [About Embodiment 9] Embodiment 9 is another example of the metal halide discharge lamp of the present invention.

  The metal halide discharge lamp of this embodiment has the same structure and size as shown in FIG. 11, but the following was enclosed as a discharge medium.

First halide: ₃ mg of scandium iodide ScI 3,
Sodium iodide NaI 15mg
Second halide: 20 mg of halide shown in Table 12
Third halide: CesI iodide 3 mg
Noble gas: Argon 20 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as in the present embodiment was manufactured except that cesium iodide CsI was not enclosed.

  Further, as a conventional example, a metal halide discharge lamp in which 40 mg of mercury was sealed in addition to the same specification as that of the present embodiment except that cesium iodide CsI was not sealed was manufactured. Further, as a comparative example, a product in which cesium iodide CsI was sealed in addition to the same specification as the conventional example was manufactured.

  Then, Table 12 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra for the present embodiment, the comparative example, and the conventional example with the lamp input constant at 400 W. In all of the present embodiment, the conventional example, and the comparative example, 400 Torr of nitrogen was sealed in the outer tube that accommodates the arc tube.

[Table 12]
Lamp CsI Second halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a None-101 62
b Yes-98 61
2 a None AlI ₃ 96 65
b Yes Same as above 106 67
3 a None ZnI ₂ 94 68
b Yes Same as above 108 70
4 a None GaI ₃ 97 67
b Yes Same as above 107 70

As is apparent from Table 12, in the conventional example in which mercury is encapsulated, the luminous efficiency is slightly lowered when cesium iodide CsI is encapsulated.

  Further, in the comparative example in which mercury is not sealed (a of lamps 2 to 4), the luminous efficiency is lower than that in the conventional example in which mercury is sealed.

  On the other hand, in this embodiment (b of lamps 2 to 4), the light emission efficiency is improved and is better than the conventional example. This is because mercury is emitted in addition to the emission of sodium Na and scandium Sc in the conventional example, and mercury has low luminous efficiency as described above. On the other hand, in the present embodiment, the energy consumed for light emission is not distributed to mercury, but all is used for light emission of the light emitting metal, so that the light emission efficiency is clearly improved.

  Further, in this embodiment, the color rendering is also slightly improved as compared with the comparative example (a of lamps 2 to 4).

  [About Embodiment 10] Embodiment 10 is another example of the metal halide discharge lamp of the present invention.

  In the present embodiment, in the structure of the metal halide discharge lamp shown in FIG. 11, the arc tube 1 has a size with an inner diameter of 12 mm and a distance between electrodes of 17 mm. And the following were enclosed as a discharge medium.

First halide: 1.5 mg of scandium iodide ScI ₃ ,
Sodium iodide NaI 7.5mg
Second halide: 5 mg of the halide shown in Table 13
Third halide: Cesium iodide CsI 1.5 mg
Noble gas: Argon 20 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as this embodiment was manufactured except that cesium iodide CsI was not enclosed.

  Further, as a conventional example, a metal halide discharge lamp was manufactured in which 12.5 mg of mercury was sealed in addition to the same specification as that of the present embodiment except that cesium iodide CsI was not sealed. Further, as a comparative example, a product in which cesium iodide CsI was sealed in addition to the same specification as the conventional example was manufactured.

  Then, Table 13 shows the results of measuring the luminous efficiency and the color rendering properties (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example with the lamp input constant 100 W and lighting. In all of the present embodiment, the conventional example, and the comparative example, 400 Torr of nitrogen was sealed in the outer tube that accommodates the arc tube.

[Table 13]
Lamp CsI Second halide Luminous efficiency Color rendering
(Lm / W) (Ra)
1 (conventional example) a None-71 61
b Yes-69 60
2 a None AlI ₃ 67 65
b Yes Same as above 77 66
3 a None NiI ₂ 65 68
b Yes Same as above 76 68
4 a None MnI ₂ 68 64
b Yes Same as above 77 63

In this embodiment, the same tendency as in Embodiment 9 was recognized. [About Embodiment 11] This embodiment is another example of the metal halide discharge lamp of the present invention.

  The metal halide discharge lamp of the present embodiment has a size of the arc tube 1 having an inner diameter of 25 mm and an interelectrode distance of 60 mm in the structure of the metal halide discharge lamp shown in FIG. And the following were enclosed as a discharge medium.

First halide: 12 mg of dysprosium iodide DyI ₃ ,
Thallium iodide TlI 3mg
Second halide: 40 mg of the halide shown in Table 14
Third halide: Cesium iodide CsI 15 mg
Noble gas: Argon 18 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as in the present embodiment was manufactured except that cesium iodide CsI was not enclosed.

  Further, as a conventional example, a metal halide discharge lamp was manufactured in which 150 mg of mercury was sealed in addition to the same specification as that of this embodiment except that cesium iodide CsI was not sealed. Further, as a comparative example, a product in which cesium iodide CsI was sealed in addition to the same specification as the conventional example was manufactured.

  Then, Table 14 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example when the lamp input is kept constant at 1 kW. In all of the present embodiment, the conventional example, and the comparative example, 400 Torr of nitrogen was sealed in the outer tube that accommodates the arc tube.

[Table 14]
Lamp CsI Second halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a None-81 92
b Yes-80 93
2 a None AlI ₃ 74 92
b Yes Same as above 88 93
3 a None SbI ₃ 76 91
b Yes Same as above 87 92
4 a None FeI ₂ 75 92
b Yes Same as above 86 92

In this embodiment, the same tendency as in Embodiments 9 and 10 was recognized.

  [About Embodiment 12] Embodiment 12 is another example of the metal halide discharge lamp of the present invention.

  The metal halide discharge lamp of the present embodiment has a size in which the arc tube 1 has an inner diameter of 32 mm and an interelectrode distance of 30 mm in the structure of the metal halide discharge lamp shown in FIG. And the following were enclosed as a discharge medium.

First halide: 4 mg of dysprosium bromide DyBr ₃ ,
4 mg of holmium bromide ₃
Thulium bromide TmBr ₃ 4mg
Second halide: 30 mg of halide shown in Table 15
Third halide: CesI iodide CsI 5 mg
Noble gas: Argon 100 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as the present embodiment was manufactured except that cesium iodide CsI was not enclosed.

  Further, as a conventional example, a metal halide discharge lamp in which 90 mg of mercury was sealed in addition to the same specification as that of the present embodiment except that cesium iodide CsI was not sealed was manufactured. Further, as a comparative example, a product in which cesium iodide CsI was sealed in addition to the same specification as the conventional example was manufactured.

  Then, Table 15 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example when the lamp input is turned on at a constant 2 kW.

[Table 15]
Lamp CsI Second halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a None-94 91
b Yes-93 92
2 a None AlI ₃ 87 92
b Yes Same as above 101 93
3 a None MnI ₂ 86 90
b Yes Same as above 100 92
4 a None FeI ₂ 88 92
b Yes Same as above 102 93

A tendency similar to that of Embodiments 9 to 11 was also observed in this embodiment.

  [About Embodiment 13] Embodiment 13 is another example of the metal halide discharge lamp of the present invention.

The metal halide discharge lamp of the present embodiment has a size in which the arc tube 1 has an inner diameter of 20 mm and an interelectrode distance of 42 mm in the structure of the metal halide discharge lamp shown in FIG. The inside of the outer tube 49 was evacuated to 10 ⁻⁴ Torr or less. And the following were enclosed as a discharge medium.

First halide: ₃ mg of scandium iodide ScI 3,
Sodium iodide NaI 15mg
Second halide: 20 mg of halide shown in Table 16
Noble gas: Argon 20 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as the present embodiment was manufactured except that 400 Torr of nitrogen was enclosed in the outer tube 49 as a gas.

  Furthermore, as a conventional example, 40 mg of mercury was further sealed, and a gas was sealed in the outer tube 49 in the same manner as described above, and a vacuum was used instead of gas as a comparative example.

  Table 16 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example when the lamp input is kept constant at 400 W.

[Table 16]
Lamp Outer tube 2nd halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a gas-101 62
b Vacuum-103 63
2 a gas AlI ₃ 96 65
b Vacuum Same as above 106 67
3 a gas FeI ₂ 95 68
b Vacuum Same as above 107 70
4 a gas GaI ₃ 97 67
b Vacuum Same as above 108 69

As apparent from Table 16, in the conventional example and the comparative example in which mercury is sealed, there is not much difference between the luminous efficiency and the color rendering property Ra when the gas is sealed in the outer tube 49 and in the vacuum.

  On the other hand, when mercury is not sealed, the luminous efficiency is lower in the comparative example in which gas is sealed in the outer tube than in the conventional example in which mercury is sealed.

  In this embodiment in which the inside of the outer tube is evacuated, the luminous efficiency is clearly superior to the conventional example. This is because mercury is emitted in addition to the emission of sodium Na and scandium Sc in the conventional example, and mercury has low luminous efficiency as described above. In this embodiment, all energy is transferred to the luminescent metal. Further, the present embodiment is slightly superior in color rendering.

  A tendency similar to that of Embodiments 9 to 11 was also observed in this embodiment.

  [Embodiment 14] This embodiment is another example of the metal halide discharge lamp of the present invention.

The metal halide discharge lamp of the present embodiment has a size in which the arc tube 1 has an inner diameter of 12 mm and an interelectrode distance of 17 mm in the structure of the metal halide discharge lamp shown in FIG. The inside of the outer tube 49 was evacuated to 10 ⁻⁴ Torr or less. And the following were enclosed as a discharge medium.

First halide: 1.5 mg of scandium iodide ScI ₃ ,
Sodium iodide NaI 7.5mg
Second halide: 5 mg of the halide shown in Table 17
Noble gas: Argon 20 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as the present embodiment was manufactured except that 400 Torr of nitrogen was enclosed in the outer tube 49 as a gas.

  Furthermore, as a conventional example, 12.5 mg of mercury was further sealed, and a gas was sealed in the outer tube 49 in the same manner as described above, and a vacuum was used instead of gas as a comparative example.

  Table 17 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example when the lamp input is kept constant at 100 W.

[Table 17]
Lamp Outer tube 2nd halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a gas-71 61
b Vacuum-74 64
2 a gas AlI ₃ 67 65
b Vacuum Same as above 77 67
3 a gas NiI ₂ 65 68
b Vacuum Same as above 76 70
4 a gas ZnI ₂ 68 64
b Vacuum Same as above 79 66

A tendency similar to that of the thirteenth embodiment was also observed in this embodiment.

  [About Embodiment 15] This embodiment is another example of the metal halide discharge lamp of the present invention.

The metal halide discharge lamp of the present embodiment has a size of the arc tube 1 having an inner diameter of 25 mm and an interelectrode distance of 60 mm in the structure of the metal halide discharge lamp shown in FIG. The inside of the outer tube 49 was evacuated to 10 ⁻⁴ Torr or less. And the following were enclosed as a discharge medium.

First halide: 12 mg of dysprosium iodide DyI ₃ ,
Thallium iodide TlI 3mg
Second halide: 40 mg of the halide shown in Table 18
Noble gas: Argon 18 Torr
As a comparative example, a metal halide discharge lamp having the same specifications as the present embodiment was manufactured except that 400 Torr of nitrogen was enclosed in the outer tube 49 as a gas.

  Further, as a conventional example, 150 mg of mercury was further sealed and a gas was sealed in the outer tube 49 in the same manner as described above, and a vacuum was used instead of gas as a comparative example.

  Table 18 shows the results of measuring the luminous efficiency and the color rendering property (average salt color evaluation number) Ra of the present embodiment, the comparative example, and the conventional example when the lamp input is turned on at a constant 1 kW.

[Table 18]
Lamp Outer tube 2nd halide Luminous efficiency (lm / W) Color rendering (Ra)
1 (conventional example) a gas-81 92
b Vacuum-83 93
2 a gas AlI ₃ 74 92
b Vacuum Same as above 88 93
3 a gas SbI ₃ 76 91
b Vacuum Same as above 87 92
4 a gas MnI ₂ 75 92
b Vacuum Same as above 86 92

A tendency similar to that of Embodiments 13 and 14 was also observed in this embodiment.

  [About Embodiment 16] This embodiment is another example of the metal halide discharge lamp of the present invention.

    FIG. 16: is a front view which shows the metal halide discharge lamp in the 7th form for implementing this invention. The same parts as those in FIG. 11 are denoted by the same reference numerals and description thereof is omitted. This embodiment is different in that it is a long arc type and is configured for DC lighting.

  That is, the arc tube 41 has an inner diameter of 18 mm, and the cathode 41a and the auxiliary electrode 41b are sealed at one end and the anode 41c is sealed at the other end.

  The cathode 41a is formed by winding a tungsten wire having a diameter of 0.4 mm around the inner end of a thorium-containing tungsten rod having a diameter of 1 mm and a length of 15 mm.

  The auxiliary electrode 41b is made of a 0.3 mm tungsten wire.

  The anode 41c is made of a tungsten rod having a tip end side of 1.8 mm and a base end side of 1.2 mm.

  The cathode 41a, the auxiliary electrode 41b, and the anode 41c are respectively connected to a sealing foil 41d made of molybdenum that is hermetically embedded in the sealing portion 41e.

  The anode 41 c is connected to the base 50 through the sealing foil 41 e, the conductor 48 ′, and the flare stem 44.

  The auxiliary electrode 41b is connected to the conductor 48 'via the starting resistor 45'.

  The cathode 41 a is connected to the base 50 via a conductor 48 ″ and a flare stem 44.

  The distance between the electrodes is set to 40 mm.

  At the end of the arc tube 41 on the cathode 41a side, a heat insulating film 41f mainly composed of platinum is formed.

  The outer tube 49 is made of a glass tube having an inner diameter of 40 mm, and the inside is evacuated.

  The following was enclosed as a discharge medium.

First halide: ₃ mg of scandium iodide ScI 3,
Sodium iodide NaI 15mg
Second halide: 20 mg of halide shown in Table 19
Noble gas: 280 Torr
As a comparative example, a lamp having the same specifications as in this embodiment was manufactured except that 40 mg of mercury was enclosed instead of the second halide.

  Then, each of the five lamps of this embodiment and three of the comparative example lamps were manufactured, and the DC output was performed at a constant rated output of 360 W. The lamp voltage (V), luminous efficiency (lm / W), color rendering The results of measuring the property (average color rendering index) Ra and the color temperature (K) are shown in Table 19 as average values.

[Table 19]
Lamp Second halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 (Comparative Example)-132 101 62 4320
2 AlI ₃ 112 96 65 4120
3 ZnI ₂ 120 98 65 4160
4 GaI ₃ 125 97 67 4130

As is clear from Table 19, the light emission efficiency of this embodiment is slightly lower than that of the comparative example, but other characteristics are not inferior.

  Next, Table 20 shows the results of measuring the color rendering property Ra and the color temperature (K) when the lamp input is 200 W, 250 W, and 300 W for the lamp 3 (this embodiment) and the lamp 1 (comparative example) in Table 19. Show.

[Table 20]
Lamp Item 200W 250W 300W
1 (Comparative example) Ra 38 46 57
Color temperature (K) 6010 5680 5210
3 Ra 59 62 63
Color temperature (K) 4500 4210 4150

As is apparent from Table 20, in the comparative example, the color rendering property Ra decreased and the color temperature (K) increased as the lamp input decreased from the rated value. On the other hand, there was little change in this form. That is, this embodiment can be dimmed.

  In addition, with respect to each lamp of this embodiment and the comparative example, whether or not the arc tube ruptures when performing horizontal lighting under the condition of lighting for 2 hours at 400 W increased by 10% with respect to the rating and turning off for 10 minutes, and 2 for rated lighting. The instantaneous restart voltage after the light was turned off for 2 seconds was measured. As a result, even after about 2500 hours of lighting, the arc tube did not rupture, and the average value of the instantaneous restart voltage was as shown in Table 21.

[Table 21]
Lamp Second halide restart voltage (kV)
1 (Comparative Example) -1.8
2 AlI ₃ 0.89
3 ZnI ₂ 0.8
4 GaI ₃ 1.0

In this embodiment, the restart voltage is significantly lower than that of the comparative example.


[About Embodiment 17] Embodiment 17 is another example of a metal halide discharge lamp.

  The metal halide discharge lamp of this embodiment encloses the following as a discharge medium in the structure and size of a metal halide discharge lamp suitable for a moving body headlamp shown in FIG.

First halide: scandium iodide ScI ₃ 0.14 mg,
Sodium iodide NaI 0.7mg
Second halide: 0.4 mg of the halide shown in Table 19
Noble gas: Xenon 5 atm As a conventional example, 1 mg of mercury was further sealed.

  Table 22 shows the results of measuring the lamp voltage, the luminous efficiency, the color rendering property (average salt color evaluation number) Ra, and the color temperature of the present embodiment and the conventional example when the lamp input is 35 W constant.

[Table 22]
Lamp Second halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 (conventional example)-83 87 63 4120
2 AlI ₃ 65 81 68 3960
3 FeI ₂ 70 79 71 4210
4 ZnI ₂ 75 81 65 3830
5 MnI ₂ 66 81 65 4230
6 GaI ₃ 76 78 65 4330

The lamp voltage in the conventional example is determined by the amount of mercury enclosed, but in this embodiment, it is determined by the amount of evaporation of the second halide. Therefore, the required lamp voltage can be easily obtained by keeping the arc tube warm. As can be seen from Table 22, in this embodiment, the lamp voltage is lower than the conventional example, but it is 50 V or more, and this type of small metal halide discharge lamp is lit using an electronic lighting circuit. No problem in practical use. In terms of characteristics, the luminous efficiency is a little inferior, but there is a slight emission of added metal (such as aluminum Al) in the visible range, so the color rendering tends to improve.

    FIG. 17 is a chromaticity diagram illustrating changes in chromaticity of the lamp 2 and the lamp 1 in Table 22 according to the seventeenth embodiment.

  This chromaticity diagram shows the white chromaticity range described in the description of automotive lamps in Japanese Industrial Standard JIS D 5500-1984. A curve E in the figure shows a change in chromaticity of the present embodiment. Curve F shows the change in chromaticity of the conventional example. The number given near the measurement point of each curve shows the elapsed time (seconds) after the start of lighting. These measurements were made by lighting each lamp with a lighting circuit that was set so that a 2.6 A lamp current would flow immediately after the power was input, and the current was gradually reduced to a constant lamp power of 35 W. It was.

  As apparent from FIG. 17, in this embodiment, the light emission enters the white range within 0.5 seconds after lighting, whereas in the conventional example, the light emission enters the white range after 18 seconds.

  Next, Table 23 shows the results of measuring the average color rendering index Ra and the color temperature (K) when the lamps 2 and 1 in Table 22 are turned on with lamp inputs 15 W, 20 W, 25 W and 30 W.

[Table 23]
Lamp Item 15W 20W 25W 30W
1 (conventional example) Ra 40 45 58 61
Color temperature (K) 5640 4970 4630 4350
2 Ra 63 64 65 66
Color temperature (K) 4280 4220 4110 4040

Since the lamp 1 (conventional example) has a high vapor pressure of mercury, even if the lamp input is reduced to 15 W, all the mercury is evaporated. For this reason, as the lamp input decreases, the emission of mercury becomes dominant and the color temperature rises.On the other hand, the color rendering property decreases, so the conventional example is suitable for dimming in a practical sense. You will understand that

  On the other hand, it can be understood that the lamp 2 (the present embodiment) is sufficiently suitable for dimming with little change in color rendering properties and color temperature.

  Furthermore, Table 24 shows the result of measuring the restart voltage at the time of instant restart (hot restart) of this embodiment. The measurement was performed by measuring the restart voltage when the lamp was turned on and off for 30 minutes and restarted after 10 seconds. In addition, when the light extinction time becomes long, the electrode temperature decreases and it becomes difficult to start. On the other hand, the vapor pressure of mercury or metal halide in the arc tube decreases as the turn-off time becomes longer, and it becomes easier to start. As a result of these conflicting tendencies, restart is most difficult to start when the turn-off time is about 10 seconds.

[Table 24]
Lamp Second halide restart voltage (kV)
1 (conventional example)-15.2
2 AlI ₃ 8.7
3 FeI ₂ 9.1
4 ZnI ₂ 9.6
5 MnI ₂ 9.3
6 GaI ₃ 8.3

The lamp 1 (conventional example) has a high starting voltage because the mercury vapor pressure is still high.

  On the other hand, in the lamps 2 to 6 (this embodiment), the metal vapor pressure of the second metal halide is clearly lower than that of mercury during steady lighting. Still, 10 seconds after extinction is when the vapor pressure difference between the metal vapor pressure of metal halide and mercury is the smallest. This indicates that the present embodiment has remarkably good restart characteristics compared to the conventional example in which mercury is enclosed.

  Next, Table 25 shows the results of measuring the color characteristics in the vicinity of the electrodes when the present embodiment is lit with direct current. This is obtained by projecting the lamp on a screen when the lamp is turned on with a lamp input of 35 W, and measuring the color temperature (K) between the vicinity of the anode and the vicinity of the cathode.

[Table 25]
Lamp Second halide Anode-side color temperature (K) Cathode-side color temperature (K)
1 (conventional example)-5330 3720
2 AlI ₃ 4210 3840
3 FeI ₂ 4420 4010
4 ZnI ₂ 4080 3650
5 MnI ₂ 4450 4060
6 GaI ₃ 4530 4130

The lamp 1 (conventional example) has a large difference in color temperature between the anode side and the cathode side. It is impossible to cover such a color temperature difference with the design of the headlamp.

  On the other hand, the lamps 2 to 6 (the present embodiment) are sufficiently suitable for practical use because the color temperature difference is small.

  [About Embodiment 18] Embodiment 18 is another example of a metal halide discharge lamp.

  The metal halide discharge lamp of this embodiment is a metal halide discharge lamp that is attached to the moving headlamp shown in FIG. 9, and both ends of the outer tube 21 are hermetically sealed in the sealing portions 1a and 1a of the arc tube 1, respectively. It has a configuration that is worn and evacuated. Other configurations are the same as those of the sixth embodiment including the discharge medium. In the conventional example as well, in the sixth embodiment, the outer tube was evacuated.

  Table 12 shows the measurement results of lamp voltage (V), luminous efficiency (lm / W), color rendering (average color rendering index) Ra, and color temperature (K) for this embodiment and the conventional example.

[Table 26]
Lamp Second halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 (conventional example)-84 89 63 4010
2 AlI ₃ 70 94 68 3890
3 FeI ₂ 76 91 73 4120
4 ZnI ₂ 81 91 68 3720
5 MnI ₂ 71 92 67 4110
6 GaI ₃ 80 90 65 4330

In this embodiment, since the inside of the outer tube is evacuated, the lamp voltage is increased and the luminous efficiency is dramatically improved. On the other hand, the conventional example was only slightly improved.

  [About Embodiment 19] Embodiment 19 is another example of a metal halide discharge lamp.

  In the metal halide discharge lamp of the present embodiment, the discharge medium was enclosed as follows in the same structure and size as the metal halide discharge lamp that can be used for the headlamp of the moving body shown in FIG.

First halide: scandium iodide ScI ₃ 0.14 mg and
Sodium iodide NaI 0.7mg
Second halide: 0.4 mg of zinc iodide ZnI ₂ and 0.1 mg of the added halide shown in Table 27
Noble gas: Xenon 5 atm Then, the lamp voltage (V), luminous efficiency (lm / W), color rendering property (average color rendering index) Ra and color temperature (K) were measured for this embodiment. Shown in

[Table 27]
Lamp Additive halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 MgI ₂ 88 81 65 3890
2 NiI ₂ 91 80 66 3990
3 CoI ₂ 88 82 67 4020
4 CrI ₂ 96 82 64 4110
5 SbI ₃ 83 79 66 3810
6 ReI ₂ 86 80 66 3960

The second halide generally has a lower vapor pressure than mercury, but at the same pressure, it contributes more to the lamp voltage formation than mercury.

  However, since mercury has a constantly high vapor pressure, mercury is completely evaporated in a small metal halide discharge lamp with a small load such as a rated lamp power of 100 W or less for a headlight of a moving body. For this reason, the lamp voltage can be adjusted by the amount of mercury enclosed.

  On the other hand, in the case of the present invention in which the second halide is sealed instead of mercury, since the vapor pressure is saturated at the stage of incomplete evaporation of the sealed halide, the lamp voltage increases further. do not do.

  However, the lamp voltage can be further increased by enclosing a plurality of types of second halides as in this embodiment. That is, when one halide of the second halide is saturated, evaporation of the added second halide contributes to an increase in lamp voltage. Accordingly, the lamp voltage can be increased when a plurality of types of second halides are mixed than when one type is used.

  [About Embodiment 20] Embodiment 20 is another example of a metal halide discharge lamp.

  In the metal halide discharge lamp of this embodiment, a discharge medium is enclosed as follows in the same structure and size as the metal halide discharge lamp that can be used for the moving headlamp shown in FIG.

First halide: scandium iodide ScI ₃ 0.14 mg and
Sodium iodide NaI 0.7mg
Second halide: 0.4 mg of the halide shown in Table 28
Third halide: Cesium iodide CsI 0.1 mg
Noble gas: Xenon 5 atm As a conventional example, a metal halide discharge lamp having the same specifications as in this embodiment was manufactured except that 1 mg of mercury was enclosed instead of the second halide.

  Then, for the present embodiment and the conventional example, the lamp input 35W is lit at a constant level, and the lamp voltage (V), luminous efficiency (lm / W), color rendering (average color rendering index) Ra, and color temperature (K) are set. Table 28 shows the measurement results.

[Table 28]
Lamp Second halide Lamp voltage Luminous efficiency Color rendering Color temperature
(V) (lm / W) (Ra) (K)
1 (conventional example)-83 86 63 4140
2 AlI ₃ 63 93 68 3940
3 FeI ₂ 68 92 70 4180
4 ZnI ₂ 73 94 66 3800
5 MnI ₂ 65 94 65 4200
6 GaI ₃ 75 92 65 4310

In this embodiment, by adding cesium iodide CsI as the third halide, the color rendering property Ra and the color temperature are hardly changed. However, since the arc temperature distribution is flattened, the heat loss is reduced. The luminous efficiency is improved. However, in the conventional example in which mercury is enclosed, the efficiency is not improved even if the third halide is added.

  Moreover, since there is no light emission of mercury with low light emission efficiency, the light emission efficiency is higher than that of the conventional example.

  Next, Table 29 shows the luminous efficiency (lm / W) when the amount of the cesium iodide CsI enclosed in the third halide is changed in the lamp 3.

[Table 29]
CsI enclosed amount (mg) Luminous efficiency (lm / W)
0.005 83
0.01 85
0.05 88
0.1 92
0.3 91
0.5 90
1.0 89
2.0 84
2.5 79

From Table 29, the addition of CsI is effective from 0.01 mg. On the other hand, if the addition amount is too large, the vapor pressure of the luminescent metal is lowered and the efficiency is lowered.

  Furthermore, Table 30 shows the results of measuring the restart voltage at the time of an instantaneous restart (hot restart) under the same conditions as in the seventeenth embodiment.

[Table 30]
Lamp Second halide restart voltage (kV)
1 (conventional example)-15.2
2 AlI ₃ 9.2
3 FeI ₂ 9.6
4 ZnI ₂ 10.1
5 MnI ₂ 9.8
6 GaI ₃ 8.9

In this embodiment, the restart voltage is remarkably lower than the conventional example in which mercury is encapsulated, but the restart voltage tends to be slightly higher than in the case where cesium iodide CsI which is the third halide is not encapsulated. There is. However, there is no problem at all practically.

  [About Embodiment 21] Embodiment 21 is another example of a metal halide discharge lamp.

    FIG. 18 is a front view showing a metal halide discharge lamp in the eighth embodiment for carrying out the present invention. In the figure, the same parts as those in FIG. The present embodiment is common in that it is suitable for a headlamp for a moving body, but is different in that it is configured to be lit in direct current.

That is, _2K is a cathode and _2A is an anode.

  The hermetic container 1 has an oval shape with an inner diameter of 4 mm and a length of 7 mm, and is provided with sealing portions 1 a having a length of 30 mm at both ends.

Cathode _{2 K} consists diameter 0.4 mm, length 6mm thorium containing tungsten rod. The base end portion is welded to one end of a molybdenum foil 3 having a width of 1.5 mm, a length of 15 mm, and a thickness of 15 μm embedded in the sealing portion 1a.

The anode _{2 A} is composed of diameter 0.8 mm, tungsten rod length 6 mm. The base end portion is welded to one end of the same molybdenum foil 3 as described above.

  The external lead wire 4 is made of a conductor having a diameter of 0.5 mm and a length of 25 mm, and is welded to the other end of the molybdenum foil 3.

  In order to manufacture the metal halide discharge lamp having the above structure, first, a sealed tube for forming a sealing portion 1 a is bonded to both ends of the hermetic container 1.

Next, after inserting the connection assembly of the cathode 2 _K , the molybdenum foil 3 and the external lead wire 4 into one sealing tube, the sealing tube is heated and melted using an oxyhydrogen burner and sealed with a pinch seal. sealed by sealing the cathode 2 _K in the airtight container 1.

Thereafter, the first and second halides are sealed in the airtight container 1 from the other sealing tube in a nitrogen gas atmosphere, and the connection assembly of the anode 2 _A , the molybdenum foil 3 and the external lead wire 4 is sealed. The tube is inserted into the tube, and a predetermined distance between the electrodes is set to 4.2 mm.

Further, these assemblies are attached to an exhaust system through a sealing tube to evacuate the inside of the hermetic container 1, and after introducing xenon at 2 atm, the other sealing tube is mounted while cooling the hermetic container 1. the pinch seal is heated melted in an oxyhydrogen burner to seal the anode 2 _a in the airtight container 1 to complete the metal halide discharge lamp. Among the discharge media, the following were enclosed as halides.

First halide: 0.17 mg of scandium iodide ScI ₃ ,
Sodium iodide NaI 0.83mg
Second halide: Lamp 2 is ZnI ₂ 0.4 mg
Lamp 3 is Al ₃ 0.2mg
Lamp 4 is 0.4 mg FeI ₂
In addition, as a conventional example (lamp 1), a metal halide discharge lamp having the same specifications as in the present embodiment was manufactured except that 1 mg of mercury was enclosed instead of the second halide.

  Thus, with respect to the lamp 2 (this embodiment) and the lamp 1 (conventional example), the luminous efficiency (lm / W) and color rendering (when the lamp input is turned on at 20 W, 25 W, 30 W and 35 W with respect to the rated 35 W, Table 31 shows the results of measuring the average color rendering index Ra and the color temperature (K).

[Table 31]
Lamp Lamp power Luminous efficiency Color rendering Color temperature
(W) (lm / W) (Ra) (K)
1 (conventional example) 20 45 4970
35 80 65 4100
2 20 64 4400
25 66 4310
30 69 4240
35 75 70 4190

FIG. 19 is a chromaticity diagram showing the rise of spectral characteristics of the metal halide discharge lamp in the eighth embodiment of the present invention in comparison with the conventional example. In the figure, a curve G shows the rising of the luminous flux of this embodiment. Curve H shows the rise of the luminous flux of the conventional example.

  This form is in the white region from the beginning of lighting. In the conventional example, it took about 1 minute to enter the white region.

  Next, each lamp was lit for 60 minutes at 42 W, which is a 20% increase in the rated lamp power, and was subjected to a blinking test for 15 seconds to investigate whether or not the hermetic container had ruptured. There was nothing.

  Further, Table 32 shows the results of the measurement of the restart voltage necessary for the instantaneous restart after 2 seconds from turning off.

[Table 32]
Lamp restart voltage (kV)
1 12
2 5
3 4
4 4.3

FIG. 20 is a graph showing the relationship with the luminous flux rise time when the rare gas filling pressure is changed in the metal halide discharge lamp of the eighth embodiment of the present invention shown in FIG. In the figure, the horizontal axis represents the xenon sealing pressure (atmospheric pressure), and the vertical axis represents the luminous flux rise time (seconds).

  From the figure, it was found that when the sealed pressure of xenon is 1 atm or more, the rise time of the light beam is suddenly shortened and becomes practical.

FIG. 21 shows the relationship between the lamp voltage (V) when the amount of enclosed ZnI ₂ (mg / cc) is changed as the second halide in the metal halide discharge lamp of the eighth embodiment of the present invention shown in FIG. It is a graph which shows.

From the figure, it can be understood that if 1 mg / cc or more of ZnI ₂ is sealed, the lamp voltage can be increased to 30 V or more, which is a desired value when the electronic lighting circuit is used for lighting.

  [Embodiment 22] Embodiment 221 is an example of a lighting circuit for lighting the metal halide discharge lamp of the present invention.

    FIG. 22 is a circuit diagram showing an example of a lighting device for lighting the metal halide discharge lamp of the present invention. In this embodiment, the metal halide discharge lamp is configured to be lit by direct current. In the figure, 71 is a DC power source, 72 is a chopper, 73 is a control means, 74 is a lamp current detection means, 75 is a lamp voltage detection means, 76 is a starting means, and 77 is a metal halide discharge lamp.

  The DC power supply 71 is a battery or a rectified DC power supply. In the case of a mobile object, a battery is generally used. However, it may be a rectified DC power source that rectifies AC. If necessary, smoothing is performed by connecting electrolytic capacitors 71a in parallel.

  The chopper 72 converts the DC voltage into a voltage having a required value and controls the metal halide discharge lamp 77 as required. When the DC power supply voltage is low, a step-up chopper is used, and when it is high, a step-down chopper is used.

  The control means 73 controls the chopper 72. For example, immediately after lighting, a metal halide discharge lamp 77 is supplied with a lamp current more than three times the rated lamp current from the chopper 72, and thereafter, the lamp current is gradually reduced as time passes, and is controlled so as to eventually reach the rated lamp current. To do.

  The lamp current detection means 74 is inserted in series with the lamp, detects the lamp current, and inputs the control input to the control means 73.

  The lamp voltage detection means 75 is connected in parallel with the lamp, detects the lamp voltage, and inputs the control voltage to the control means 73.

  The control means 73 generates a constant power control signal by feedback input of the detection signal of the lamp current and the lamp voltage, and controls the chopper 72 at a constant power. Further, the control means 73 has a built-in microcomputer in which a temporal control pattern is incorporated in advance, and immediately after the lamp is turned on, a lamp current more than three times the rated lamp current is passed through the metal halide discharge lamp 77. The chopper 72 is configured to control the lamp current.

  The starting means 76 is configured to supply a pulse voltage of 20 kV to the metal halide discharge lamp 67 at the time of starting.

  Thus, according to the metal halide discharge lamp lighting device of the present example, a required light flux is generated immediately after lighting while DC lighting. As a result, it is possible to realize lighting with a luminous flux of 25% and a luminous flux of 80% after 1 second after turning on the power necessary as a headlamp for a moving body such as an automobile.

  In the case of this example, since a DC-AC conversion circuit is not necessary, the cost can be reduced by about 30% compared to AC lighting. Further, the weight can be reduced by 15%. Along with this, the lighting circuit becomes inexpensive.

  [About Embodiment 23] Embodiment 23 is another example of a lighting circuit for lighting a metal halide discharge lamp of the present invention.

    FIG. 23 is a circuit diagram showing another example of a lighting device for lighting the metal halide discharge lamp of the present invention. The same parts as those in FIG. This embodiment is different in that the metal halide discharge lamp is configured to be lit with alternating current.

  Reference numeral 78 denotes AC conversion means. The AC conversion means 78 is composed of a full bridge inverter. That is, a pair of switching means 78a and 78a in series is connected in parallel between the output ends of the chopper 72 to form a bridge circuit, and the oscillation output of the oscillator 78b is switched in the diagonal direction of the four switching means 78a. By alternately supplying to the means, high-frequency alternating current is generated between the output ends of the bridge circuit.

  The metal halide discharge lamp 77 is turned on by high frequency alternating current.

  Also in this AC lighting type configuration, the same control as in FIG. 16 is performed.

  [About Embodiment 24] Embodiment 24 is another example of a lighting device using the metal halide discharge lamp of the present invention.

    24 and 25 show a headlamp for a moving body as another example of an illuminating device using the metal halide discharge lamp of the present invention, FIG. 24 is an overall conceptual diagram, and FIG. 25 is a part of an optical distributor. FIG. In each figure, 81 is a lighting circuit, 82 is a light distributor, 83 is a main optical fiber, 84 is an optical shutter 85, an individual optical fiber, and 86 is a lamp.

  As the lighting circuit 81, the lighting circuit shown in FIG. 22 or FIG. 23 can be used.

  The optical distributor 82 includes a case 82a, a condensing reflection surface 82b, a metal halide discharge lamp 82c, and an optical connector 82d. Then, the light generated from the metal halide discharge lamp 82c is distributed from the portion of the optical connector 82d to the main optical fiber 83.

  The main optical fiber 83 transmits the light distributed from the light distributor 82 to the optical shutter 84.

  The optical shutter 84 selectively transmits to each lamp 86 via the individual fiber 85.

  The lamp unit 86 includes a high beam lamp unit 86a, a low beam lamp unit 86b, and a fog lamp unit 86c, and two sets are disposed on both sides of the front part of a moving body such as an automobile.

  [About Embodiment 25] Embodiment 25 is an example of a metal halide discharge lamp suitable for use in Embodiment 24.

  That is, the rated lamp power is 80 W, and the distance between the electrodes is set to 2 mm in order to increase the light collection efficiency. The other structure is the same as that of FIG. 6, but the following is enclosed as a discharge medium.

First halide: 0.3 mg of scandium iodide ScI ₃ ,
Sodium iodide NaI 1.5mg
Second halide: lamp 2 is ZnI ₂ 1 mg, AlI ₃ 1 mg, MnI ₂ 1 mg
Lamp 3 is ZnI ₂ 2 mg, GaI ₃ 1 mg, CrI ₂ 1 mg
Noble gas: xenon 5 atm As a conventional example, a metal halide discharge lamp having the same specifications as in the present embodiment was manufactured except that 15 mg of mercury was enclosed instead of the second halide.

  Then, the result of measuring the lamp voltage (V), the luminous efficiency (lm / W), the color rendering property (average color rendering index) Ra, and the color temperature (K) by lighting the present embodiment and the conventional example at a constant rating of 80 W. Is shown in Table 33.

[Table 33]
Lamp Lamp voltage (V) Luminous efficiency (lm / W) Color rendering (Ra) Color temperature (K)
1 (conventional example) 63 94 63 4020
2 58 88 68 3920
3 62 89 69 4110

As can be understood from Table 33, in this embodiment, characteristics substantially equivalent to those of the conventional example in which mercury is sealed can be obtained. Further, in the case of the system according to the present embodiment, it is extremely useful that dimming is possible by changing the input and dimming is possible.

  [About Embodiment 26] Embodiment 26 is another example of an illumination device using the metal halide discharge lamp of the present invention.

    FIG. 26 is a cross-sectional view showing a downlight as another example of an illumination device using the metal halide discharge lamp of the present invention.

  In the figure, 91 is a metal halide discharge lamp, and 92 is a downlight body.

  Since the base 92a is embedded in the ceiling, the base 92a has a ceiling contact edge e at the lower end.

  The socket 92b is attached to the base 92a.

  The reflection plate 92c is supported by the base 92a and surrounds the light emission center of the metal halide discharge lamp 91 so as to be positioned substantially at the center thereof.

The front view which shows the metal halide discharge lamp in the 1st form for implementing this invention Conceptual illustration of optical system of RGB color separation type liquid crystal projector The graph which shows the arc temperature distribution of the lamp | ramp 2 (this form) and the lamp | ramp 1 (conventional example) in Table 1 1 is a partial cross-sectional front view showing a projector lamp in which a metal halide discharge lamp according to a first embodiment for carrying out the present invention is integrated with a reflecting mirror. 4 is a conceptual diagram showing a liquid crystal projector using the projector lamp shown in FIG. 4 as an example of an illumination device using the metal halide discharge lamp of the present invention. The center section front view showing the metal halide discharge lamp in the 2nd form for carrying out the present invention. The graph which shows the relationship of the light beam rise time with respect to the enclosure pressure of xenon Xe in the metal halide discharge lamp of the 2nd form for implementing this invention. Similarly, in the metal halide discharge lamp of the second embodiment, a graph showing the relationship of the lamp voltage with respect to the enclosed amount when iron iodide FeI ₂ is used as the second halide. The front view which shows the metal halide discharge lamp in the 3rd form for implementing this invention The perspective view which shows the headlamp for moving bodies, such as for motor vehicles, as another example of the illuminating device using the metal halide discharge lamp of this invention The front view which shows the metal halide discharge lamp in the 4th form for implementing this invention Graph showing the spectral distribution of a conventional long arc metal halide discharge lamp The principal part cross-sectional front view which shows the metal halide discharge lamp in the 5th form for implementing this invention Chromaticity diagram showing rise of spectral characteristics of metal halide discharge lamp in fifth embodiment for carrying out the present invention in comparison with the conventional example The principal part cross-sectional front view which shows the metal halide discharge lamp in the 6th form for implementing this invention The front view which shows the metal halide discharge lamp in the 7th form for implementing this invention Chromaticity diagram showing change in chromaticity of lamp 2 in Table 22 and lamp 1 of conventional example in Embodiment 17 The front view which shows the metal halide discharge lamp in the 8th form for implementing this invention Chromaticity diagram showing the rise of spectral characteristics of a metal halide discharge lamp in the eighth embodiment of the present invention in comparison with the conventional example FIG. 18 is a graph showing the relationship with the luminous flux rise time when the rare gas sealing pressure is changed in the metal halide discharge lamp according to the eighth embodiment of the present invention. FIG. 18 is a graph showing the relationship of lamp voltage (V) when the amount of enclosed ZnI ₂ (mg / cc) is changed as the second halide in the metal halide discharge lamp according to the eighth embodiment of the present invention. The circuit diagram which shows an example of the lighting device which lights the metal halide discharge lamp of this invention The circuit diagram which shows the other example of the lighting device which lights the metal halide discharge lamp of this invention The conceptual diagram which shows the whole headlamp for moving bodies as another example of the illuminating device using the metal halide discharge lamp of this invention. Similarly, conceptual diagram of the optical distributor part Sectional drawing which shows the downlight as another example of the illuminating device using the metal halide discharge lamp of this invention. Conceptual diagram for explaining the lamp voltage in a metal halide discharge lamp Graph showing the emission spectrum distribution of a conventional short arc metal halide discharge lamp for projection

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Airtight container, 1a ... Sealing part, 2 ... Electrode, 2a ... Electrode shaft, 2b ... Electrode coil, 3 ... Sealing metal foil, 4 ... External lead wire

Claims (3)

Fireproof and translucent airtight container;
A pair of electrodes sealed in an airtight container and operating as one anode and the other as a cathode;
A first halide, a second halide, and a rare gas are enclosed in an airtight container in a configuration essentially free of mercury, and the first halide is made of sodium Na, scandium Sc, and a rare earth metal. One or a plurality of halides selected from the group consisting of: magnesium Mg, iron Fe, cobalt Co, chromium Cr, zinc Zn, nickel Ni, manganese Mn, aluminum Al, antimony A discharge medium that is a halide of one or more metals selected from the group consisting of Sb, beryllium Be, rhenium Re, gallium Ga, titanium Ti, zirconium Zr and hafnium Hf;
The metal halide discharge lamp is characterized in that it is configured to be lit with direct current. A metal halide discharge lamp according to claim 1;
An electronic direct current lighting device for direct current lighting of metal halide discharge lamps;
A metal halide discharge lamp DC lighting device comprising: A lighting device body;
The metal halide discharge lamp according to claim 1, wherein the metal halide discharge lamp is disposed in a lighting device body;
An electronic direct current lighting device for direct current lighting of metal halide discharge lamps;
An illumination device comprising:

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