JP2007053004A - Metal-halide lamp and lighting system using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a metal-halide lamp capable of obtaining a color temperature of 2,800 [K] to 3,700 [K] with high color rendering and high lamp efficiency and to provide a lighting system using the same. <P>SOLUTION: The halide lamp has a color temperature of 2,800 [K] to 3,700 [K] and is filled with the following light emitting substances. That is, they comprise at least rare earth metal, Na and Ca, and the rare earth metal consists of at least one kind out of Dy, Tm, and Ho and at least one out of Ce and Pr. A composition ratio M<SB>A</SB>of a group A consisting of at least one kind out of Dy, Tm and Ho out of the rare earth metal is 2 [mol%] to 10 [mol%], a composition ratio M<SB>B</SB>of a group B consisting of at least one of Ce and Pr out of the rare earth metal is 0.5 [mol%] to 4 [mol%], a composition ratio M<SB>Na</SB>of Na is 35 [mol%] to 45 [mol%], and a composition ratio M<SB>Ca</SB>of Ca is 40 [mol%] to 60 [mol%]. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a metal halide lamp and an illumination device using the same.

  Recently, metal halide lamps (hereinafter referred to as “ceramic metal halide lamps”) using arc tubes made of translucent ceramic as a material constituting the envelope are highly efficient and high color rendering lamps, for example, stores. It is widely used for indoor lighting in commercial facilities.

  In this type of ceramic metal halide lamp, in order to obtain particularly high color rendering properties, dysprosium (Dy), thulium (Tm), holmium (Ho) rare earth metal, thallium (Tl), sodium (Na), etc. are combined as the luminescent material. Is used.

As an example, in a conventional warm white type (color temperature 3500 [K]) ceramic metal halide lamp (hereinafter referred to as “conventional ceramic metal halide lamp”) having a rated power of 150 [W], 6 [mol%] of dysprosium is used as a luminescent substance. , Thulium is 6 [mol%], holmium is 6 [mol%], thallium is 9 [mol%], and sodium is 73 [mol%]. This conventional ceramic metal halide lamp is transparent, has a luminous flux of 13500 [lm], a lamp efficiency of 90 [lm / W], an average color rendering index Ra of 87, a special color rendering index R ₉ of 10, and a black body radiation locus. A lamp characteristic with a DUV of -7 representing the displacement from is obtained. However, “luminescent luminous flux”, “lamp efficiency”, “average color rendering index Ra”, “special color rendering index R ₉ ”, and “DUV” mentioned here all indicate values after 100 hours of lighting.

  In the conventional ceramic metal halide lamp, as shown in FIG. 3, a substantially cylindrical cylindrical portion 15 and a thick, substantially disc-shaped closed portion integrated by shrink fitting at both ends of the cylindrical portion 15. 16 and a substantially cylindrical thin tube portion 19 having one end portion inserted into a through hole 16a provided in the central portion of the closing portion 16 and integrated by shrink fitting. An arc tube 18 having an outer envelope 20 is used.

In this way conventional ceramic metal halide lamp, a special color rendering index R ₉ there is a particularly low.

Thus, conventionally, it has been proposed to increase the light emission in the red region by adding calcium (Ca) to the luminescent material to improve the average color rendering index Ra and the special color rendering index R ₉ (for example, patents). Reference 1).

By the way, in this type of ceramic metal halide lamp, it has been proposed to use cerium (Ce) or praseodymium (Pr) as a luminescent material in order to obtain higher efficiency (see, for example, Patent Document 2).
JP 2004-281216 A JP 2003-86130 A

  While this type of ceramic metal halide lamp is used for indoor lighting in commercial facilities such as stores, there is a strong demand for a color rendering effect that enhances the saturation of the object color of the irradiated object in stores and makes it more preferable. ing. At the same time, due to today's demand for energy saving, higher efficiency is also required.

Accordingly, the present inventors firstly achieved higher color rendering (for example, average color rendering) than conventional ceramic metal halide lamps in a ceramic metal halide lamp having a color temperature of 2800 [K] to 3700 [K] (from a light bulb color type to a warm white type). index Ra is 90 or more, the special color rendering index _{R 9} is 40 or more, in the DUV 0-10), and more efficient (e.g. lamp efficiency is attempted to realize a 94 [lm / W]) lamps.

  First, in a conventional ceramic metal halide lamp, when calcium was added to the luminescent material and the composition ratio at which high color rendering properties were obtained was examined, it was found that it was preferably 40 [mol%] or more.

  However, in a conventional ceramic metal halide lamp, it has been found that the addition of calcium to the luminous material at the above composition ratio reduces the lamp efficiency to 88 [lm / W].

  The present invention has been made based on such circumstances, and a metal halide lamp having a color temperature of 2800 [K] to 3700 [K], high color rendering, and high lamp efficiency. It aims at providing the illuminating device using.

The metal halide lamp of the present invention is a metal halide lamp having a color temperature of 2800 [K] to 3700 [K] having a ceramic arc tube in which an electrode body is arranged and a luminescent material is enclosed, The luminescent material includes at least a rare earth metal, sodium (Na) and calcium (Ca), and the rare earth metal includes at least one of dysprosium (Dy), thulium (Tm) and holmium (Ho), and cerium (Ce). And a composition ratio of group A consisting of at least one of dysprosium, thulium, and holmium among the rare earth metals is M _A [mol%], and the rare earth metals are composed of at least one of praseodymium (Pr). , At least one of cerium and praseodymium _M B [mol%] composition ratio of-loop B, _M Na [mol%] composition ratio of the sodium, when the composition ratio of the calcium and _{M Ca [mol%], M} A is 2 [mol% _{] ~10 [mol%], M} B is 0.5 [mol%] ~4 [mol %], M Na is 35 [mol%] ~45 [mol %], M Ca is 40 [mol%] ~60 It has a configuration of [mol%].

  Moreover, the illuminating device of this invention has the structure provided with the said metal halide lamp, the lighting circuit for lighting this metal halide lamp, and the lighting fixture incorporating the said metal halide lamp.

  The present invention can provide a metal halide lamp having a color temperature of 2800 [K] to 3700 [K], high color rendering, and high lamp efficiency.

  In addition, the present invention can provide an illumination device having a color temperature of 2800 [K] to 3700 [K] and high color rendering and high efficiency.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  As shown in FIG. 1, the metal halide lamp 1 with a rated power of 150 [W] according to the first embodiment of the present invention has a color temperature of 2800 [K] to 3700 [K], and one end thereof is substantially omitted. An outer tube 3 made of, for example, hard glass, which is closed in a hemispherical shape and has a stem 2 sealed at the other end, is housed in the outer tube 3. A sleeve made of, for example, quartz glass, which is positioned between the arc tube 4 and the outer tube 3 and the arc tube 4 and prevents the outer tube 3 from being broken by a broken piece even if the arc tube 4 is broken. 5 and, for example, an E-shaped base 6 attached to the other end of the outer tube 3.

  Two power supply lines 7 are sealed to the stem 2. One end portions of these power supply lines 7 are introduced into the outer tube 3 and electrically connected to external lead portions 8 of the arc tube 4 described later. On the other hand, the other end of the power supply line 7 is led out of the outer tube 3, one of which is electrically connected to the eyelet 6 a of the base 6 and the other is electrically connected to the shell 6 b of the base 6. ing.

  The power supply line 7 is made of a single metal wire obtained by integrating a plurality of metal wires. The base 6 is not limited to the E shape, and various known ones such as a pin-shaped G shape and a PG shape can be used.

  Nitrogen gas is sealed inside the outer tube 3 so as to be 40 [kPa] to 80 [kPa] at room temperature (25 [° C.]), for example. However, the inside of the outer tube 3 may be in a vacuum state as necessary.

  The outer tube 3 is not limited to a substantially cylindrical shape, but has various known shapes such as a shape in which the central portion swells most and the diameter gradually decreases as it approaches each end. Can be used.

As shown in FIG. 2, the arc tube 4 includes, for example, polycrystalline alumina composed of a main tube portion 10 that forms a discharge space 9 and thin tube portions 11 that are connected to both ends of the main tube portion 10. It has the envelope 12 which consists of translucent ceramics. The main pipe portion 10 and the narrow pipe portion 11 constituting the envelope 12 are formed by integral molding in which the members 10 and 11 are molded at the same time, and are separately molded and later shrink-fitted. It is not integrated by. Overall length _{L 1} of the envelope 12 is, for example, 48 [mm]. The main pipe portion 10 is formed by connecting a substantially cylindrical cylindrical portion 13 having a maximum inner diameter r ₁ of, for example, 11 [mm] and a wall thickness t ₁ of, for example, 0.6 [mm], and both ends thereof by integral molding. And a substantially hemispherical hemispherical portion 14. The thin tube portion 11 is substantially cylindrical and has an inner diameter r ₂ of, for example, 1.0 [mm] and a wall thickness t ₂ of, for example, 1.1 [mm].

  Here, as the envelope structure, the main tube portion 10 and the thin tube portion 11 are integrally formed as described above. However, the envelope is not limited to this, and the envelope of the arc tube in the conventional ceramic metal halide lamp is described. 3, that is, as shown in FIG. 3, a substantially cylindrical cylindrical portion 15 and a thick substantially disc-shaped blocking portion 16 integrated by shrink fitting at both ends of the cylindrical portion 15. The main pipe portion 17 having one end portion is inserted into a through-hole 16a provided in the central portion of the closing portion 16, and is formed by a substantially cylindrical thin tube portion 19 integrated by shrink fitting. Various known structures can be used. However, the envelope 20 of the arc tube 18 as typified by FIG. 3 is composed of the three parts of the cylindrical portion 15, the closing portion 16 and the narrow tube portion 19. Since the portion 16 and the thin tube portion 19 are integrated by shrink fitting, the airtightness at the joints of the members 15, 16, 19 is sufficiently maintained and the mechanical strength is prevented so as not to be damaged during shrink fitting. In order to ensure sufficiently, especially the thickness (for example, 2.6 [mm]) of the obstruction | occlusion part 16 is made thick. If the thickness of the envelope 20 is increased in this way, the light transmittance may decrease in the thick portion, or the heat conduction loss may increase, leading to a decrease in lamp efficiency. Therefore, by using an envelope in which the main pipe portion 10 and the thin tube portion 11 as shown in FIG. 2 are integrally formed, a thicker blockage than the envelope 20 as shown in FIG. Since the portion 16 is not required, the light transmittance can be increased, and the heat conduction loss can be reduced, so that the lamp efficiency can be improved.

  As a material constituting the envelopes 12 and 20, a light-transmitting ceramic such as yttrium-aluminum-garnet (YAG), aluminum nitride, yttrium oxide, or zirconia can be used in addition to the above-described polycrystalline alumina. .

Further, an electrode body 21 is disposed inside the arc tube 4 as shown in FIG. Specifically, the electrode part 22 is arranged inside the main pipe part 10 so that the tip parts face each other and the central axis X (see FIG. 2) in the longitudinal direction is located on substantially the same axis. Yes. Distance _{L e} between the electrodes 22 is, for example, 10 [mm]. Inside each narrow tube portion 11, as described above, the electrode portion 22 formed at the tip portion is positioned in the main tube portion 10, and the opposite end portion (one of the internal lead portions 23 described later). The electrode bodies 21 are inserted so that the outer lead portion 8 and the external lead portion 8) lead out to the outside of the thin tube portion 11. The inserted electrode body 21 is formed of the thin tube portion 11 and the electrode body 21 so as to cover the entire internal lead portion 23 only at the end portion of the thin tube portion 11 opposite to the main tube portion 10. It is sealed with a sealing material 24 made of glass frit poured into the gap. The sealing material 24 is present not only in the gap formed by the narrow tube portion 11 and the electrode body 21 but also outside the narrow tube portion 11 so as to cover the internal lead portion 23.

The electrode body 21 is a conductive material obtained by sintering a mixture of, for example, aluminum oxide (Al ₂ O ₃ ) and molybdenum (Mo), which has an electrode portion 22 formed at the tip portion and one end portion connected to the electrode portion 22. An internal lead portion 23 having a diameter of, for example, 0.9 [mm] and a length of, for example, 6 [mm] made of cermet, and an external lead portion 8 made of, for example, niobium having one end connected to the internal lead portion 23. Have. The other end portion of the external lead portion 8 is electrically connected to the power supply line 7.

In addition to the conductive cermet obtained by sintering a mixture of aluminum oxide (Al ₂ O ₃ ) and molybdenum (Mo), the internal lead portion 23 is a mixture of aluminum oxide (Al ₂ O ₃ ) and tungsten (W). Various known halogen-resistant materials such as a conductive cermet obtained by sintering and a simple metal molybdenum rod can be used in place of these conductive cermets.

  The electrode portion 22 has a diameter of, for example, 0.5 [mm] and a length of, for example, 16.5 [mm]. The tungsten electrode rod 25 has an outer diameter of, for example, about 0.1 mm. And an electrode coil 26 made of tungsten of 9 [mm]. The electrode rod 25 is filled with a gap formed between the thin tube portion 11 and the electrode rod 25 as much as possible, and in order to prevent the luminescent material from sinking into the gap and not contributing to light emission, for example, molybdenum. A coil 27 made of metal is attached.

  The structure of the electrode body includes the electrode portion 22, the internal lead portion 23, and the external lead portion 8. However, the structure is not limited to this, and for example, the internal lead portion and the external lead portion are formed of a single member. Various known electrode bodies can be used, such as one having a portion connected to the electrode rod 25 and the other end led out of the thin tube portion 11 and directly connected to the power supply line 7. As a result of using various electrode bodies, as a sealing method within the thin tube portion 11 of the electrode body, a known metallized sealing can be used in addition to the sealing method using the sealing material 24 described above.

  Further, a predetermined amount of a luminescent material, mercury as a buffer gas, and a rare gas such as an argon gas, for example, an argon gas, are enclosed in the arc tube 4.

The light emitting material contains at least a rare earth metal, sodium (Na), and calcium (Ca). The rare earth metal is composed of at least one of dysprosium (Dy), thulium (Tm) and holmium (Ho) and at least one of cerium (Ce) and praseodymium (Pr). Among the rare earth metals, the composition ratio of the group A consisting of at least one of dysprosium, thulium and holmium is M _A [mol%], and among the rare earth metals, the composition of the group B consisting of at least one of cerium and praseodymium. the composition ratio _M B [mol%], the composition ratio of sodium _M Na [mol%], when the composition ratio of calcium and _{M Ca [mol%], M} a is 2 [mol%] ~10 [mol % ], _{M B} is 0.5 [mol%] ~4 [mol %], M Na is 35 [mol%] ~45 [mol %], M Ca is 40 [mol%], respectively to 60 [mol%] It is prescribed.

  Here, the reason why the composition ratio of each luminescent material is defined as described above will be described.

First, on the premise that a color temperature of 2800 [K] to 3700 [K] is obtained, the color rendering properties of a conventional ceramic metal halide lamp (average color rendering index Ra is 87, special color rendering index R ₉ is 10, DUV is -7) and lamp efficiency (90 [lm / W]), higher color rendering properties (average color rendering index Ra, special color rendering index R ₉ and DUV) and higher lamp efficiency can be obtained. Thus, as a result of examining various combinations of the composition ratios of the light emitting materials, the following knowledge was obtained.

That is, the color temperature is mainly dependent respectively on the composition ratio M _A and sodium composition ratio M _Na of the rare earth metals consisting of Group A, found to be lower in accordance with the ratio of the composition ratio M _Na on the composition ratio M _A is increased It was. As a result, 3700 in order to obtain a [K] low color temperature of below, reducing the composition ratio _{M A} rare earth metal consisting of the group A below 10 [mol%], 35 [ mol%] composition ratio of sodium or I knew it should be. On the other hand, since the color temperature so as not to fall below the 2800 [K], the composition ratio _{M A} rare earth metal consisting of the group A 2 in the [mol%] or more and 45 [mol%] composition ratio of sodium I found it should be:

Next, general color rendering index Ra, the special color rendering index R ₉ and DUV is dependent respectively on mainly group composition ratio of the rare earth metals consisting of A M _A and the composition ratio M _Ca of calcium, the composition ratio M _A and the composition ratio It was found that M _Ca increased as both increased. In particular, the special color rendering index R ₉ largely depends on the calcium composition ratio M _Ca. As a result, in order to obtain a higher color rendering property while obtaining a low color temperature of 2800 [K] to 3700 [K], the calcium composition ratio M _{Ca is set} to 40 [mol%] or more and the group A is included. composition ratio M _a rare earth metal also found that should be more than 2 [mol%]. In particular, it was found that DUV greatly depends on the composition ratio M _{Ca of} calcium and the composition ratio MB of the rare earth metal composed of group _B , respectively. It was found that when the composition ratio M _Ca exceeds 60 [mol%], pink light emission becomes too conspicuous and the DUV greatly shifts to the minus region. Further, even beyond is 4 [mol%] composition ratio M _B, DUV it was found that results in a shift from the negative region to the positive region. Therefore, in order to maintain the value of DUV appropriately in the minus region, the calcium composition ratio M _{Ca is set} to 60 [mol%] or less, and the rare earth metal composition ratio M _B composed of Group B is set to 4 [mol%]. I found it should be:

Next, in order to improve lamp efficiency, it has been found that it is effective to enclose at least one of cerium and praseodymium as a luminescent material. Therefore, in case of the respective light emitting material composition ratio as described above (excluding rare earth metals consisting of Group B), in order to obtain a higher lamp efficiency, the composition ratio M _B of the rare earth metals consisting of Group B 0.5 It turned out that it should be more than [mol%].

Based on the above results, the color temperature is 2800 [K] to 3700 [K], and higher color rendering and higher lamp efficiency compared to the color rendering and lamp efficiency of the conventional ceramic metal halide lamp. as both obtained, among the rare earth metals, dysprosium, the composition ratio _{M a} of group a consisting of at least one of thulium and holmium 2 [mol%] ~10 [mol %], of rare earth metals, cerium and 0.5 [mol%] composition ratio _{M B} of the group B consisting of at least one of praseodymium ~4 [mol%], 35 [ mol%] composition ratio _{M Na} sodium to 45 [mol%] In addition, the calcium composition ratio M _Ca was defined as 40 [mol%] to 60 [mol%], respectively.

In addition, these luminescent substances are usually encapsulated in the form of metal halides rather than being encapsulated as a single metal in the encapsulation process. For example, dysprosium is dysprosium iodide (DyI ₃ ), thulium is thulium iodide (TmI ₃ ), holmium is holmium iodide (HoI ₃ ), thallium is thallium iodide (TlI), cerium is cerium iodide (CeI ₃ ), Praseodymium is encapsulated in the form of praseodymium iodide (PrI ₃ ), sodium in the form of sodium iodide (NaI), and calcium in the form of calcium iodide (CaI ₂ ). However, these are not necessarily all in the form of iodide, and some or all of the arbitrary luminescent materials may be in the form of bromide. However, since this type of metal halide lamp 1 is lit with a high load (for example, tube wall load (20) [W / cm ² ] to (40) [W / cm ² ]), the bromide and electrode portion 22 are formed. There is a possibility that excessive tungsten reacts. Therefore, when encapsulating each luminescent material, it is preferable to encapsulate mainly 95 [wt%] or more of metal halide in the form of metal iodide.

Further, the light emitting material has a color temperature of 2800 [K] to 3700 [K], and has higher color rendering properties and higher lamp efficiency compared to the color rendering properties and lamp efficiency of conventional ceramic metal halide lamps. In addition to the above-described metals as necessary, for example, neodymium (Nd), terbium (Tb), lutetium (Lu), lithium (Li), barium (Ba), strontium (Sr), etc. May be enclosed. By adding this neodymium, the lamp efficiency can be further improved. Moreover, the average color rendering index Ra can be further increased by adding these terbium and lutetium. Furthermore, by adding these lithium, barium, strontium, it is possible to further enhance the specific color rendering index R _9.

As described above, according to the configuration of the metal halide lamp 1 according to the first embodiment of the present invention, at least a rare earth metal, sodium (Na), and calcium (Ca) are included as a luminescent material, and the rare earth metal is dysprosium (Dy). At least one of thulium (Tm) and holmium (Ho) and at least one of cerium (Ce) and praseodymium (Pr), and among the rare earth metals, at least of dysprosium, thulium and holmium The composition ratio of group A consisting of one kind is M _A [mol%], among the rare earth metals, the composition ratio of group B consisting of at least one of cerium and praseodymium is M _B [mol%], and the composition ratio of sodium is M _Na [mol%], the composition ratio of calcium When the M _Ca [mol%], the _{M A 2 [mol%] ~10} [mol%], the _{M B 0.5 [mol%] ~4} [mol%], 35 [mol%] and _{M Na} ~45 _[mol%], since the _{M Ca} is set to 40 [mol%] ~60 [mol %], the color temperature is a 2800 [K] ~3700 [K] , high color rendering than conventional ceramic metal halide lamp And high lamp efficiency can be obtained.

  In particular, since the main tube portion 10 and the thin tube portion 11 constituting the envelope 12 of the arc tube 4 are integrally formed, a plurality of parts are integrated by shrink fitting or the like. Compared with the above, the light transmittance can be increased and the heat conduction loss can be reduced, so that the lamp efficiency can be further improved.

  Next, an experiment was conducted to confirm the operational effects of the metal halide lamp 1 (hereinafter simply referred to as “the product A of the present invention”) having a rated power of 150 [W] according to the first embodiment of the present invention described above. .

First, in the product A of the present invention, one having a composition ratio of each luminescent substance as shown in Table 1 was produced (hereinafter referred to as “Example a”). That is, dysprosium 3 [mol%], thulium 2 [mol%], holmium 2 [mol%], thallium 2 [mol%], cerium 2 [mol%], sodium 35 [mol%], Calcium is 54 [mol%]. However, all the luminescent materials are encapsulated in the form of iodide, and the total encapsulated amount as metal iodide is 5 [mg] (4.2 [mg / cm ³ ]). Then, the produced lamp is vertically lit so that the cap 6 faces upward, and is barely lit at the rated power (150 [W]), and the color temperature [K] when the lamp is lit for 100 hours, the average color rendering index When Ra, special color rendering index R ₉ , DUV, luminous flux (emitted luminous flux) [lm], and lamp efficiency [lm / W] were examined, the results shown in Table 1 were obtained.

  In Example a, the envelope is an envelope 12 (referred to as “integrated mold” in Table 1) in which the main tube portion 10 and the thin tube portion 11 are integrally formed as shown in FIG.

Further, it is carried out except that the envelope 20 (referred to as “assembled type” in Table 1) of the arc tube 18 of a conventional ceramic metal halide lamp having a rated power of 150 [W] as shown in FIG. 3 is used. One metal halide lamp (Example b) having the same configuration as Example a and rated power of 150 [W] was produced. Then, the produced lamp is vertically lit so that the cap 6 faces upward, and is barely lit at the rated power (150 [W]), and the color temperature [K] when the lamp is lit for 100 hours, the average color rendering index When Ra, special color rendering index R ₉ , DUV, luminous flux (emitted luminous flux) [lm], and lamp efficiency [lm / W] were examined, the results shown in Table 1 were obtained.

For reference, a conventional ceramic metal halide lamp with a rated power of 150 [W] (conventional example a) is placed in a vertical position with the base facing upward, and is barely lit at the rated power (150 [W]). The result of examining the color temperature [K], the average color rendering index Ra, the special color rendering index R ₉ , the DUV, the luminous flux (emitted luminous flux) [lm], and the lamp efficiency [lm / W] after 100 hours of lighting. Is also shown in Table 1. The luminescent materials are 6 [mol%] for dysprosium, 6 [mol%] for thulium, 6 [mol%] for holmium, 9 [mol%] for thallium, and 73 [mol%] for sodium. However, all the luminescent materials are encapsulated in the form of iodide, and the total encapsulated amount as metal iodide is 5 [mg] (4.2 [mg / cm ³ ]).

  In all of the examples a, b, and the conventional example a, the outer tube 3 is a transparent type.

As shown in Table 1, in Example a, the color temperature is 3530 [K], the average color rendering index Ra is 95, the special color rendering index R ₉ is 45, the DUV is -5.4, and the luminous flux is 14400 [ lm] and the lamp efficiency was 96 [lm / W]. In Example b, the color temperature is 3600 [K], the average color rendering index Ra is 92, the special color rendering index R ₉ is 30, DUV is −4, the luminous flux is 14100 [lm], and the lamp efficiency is 94 [ lm / W]. On the other hand, in the conventional example a, the color temperature is 3500 [K], the average color rendering index Ra is 87, the special color rendering index R ₉ is 10, DUV is −7, the luminous flux is 13500 [lm], and the lamp efficiency. Was 90 [lm / W].

  Thus, in Example a and Example b, it is confirmed that the color temperature is 2800 [K] to 3700 [K], and a high color rendering property and high lamp efficiency higher than those of conventional ceramic metal halide lamps can be obtained. It was done.

  In the above experiment, only cerium is used as the rare earth metal consisting of group B. However, praseodymium may be used instead of cerium, or praseodymium in addition to cerium may be used within the above composition ratio range. It was confirmed that the same result as above was obtained.

  In the first embodiment, the metal halide lamp having a rated power of 150 [W] is described as an example. However, the metal halide lamp can be applied to a rated power of 20 [W] to 300 [W], for example. Is.

Next, in the metal halide lamp having a rated power of 150 [W] according to the second embodiment of the present invention, as shown in FIGS. 1 and 2, the envelope 12 of the arc tube 4 is formed by integral molding. The luminous substance in the arc tube 4 is enclosed in the form of a metal halide, and the metal halide is mainly (for example, 95 [wt%] or more) metal iodide, and the total enclosed amount is 10 0.5 [mg / cm ³ ] or more, preferably in the range of 10.5 [mg / cm ³ ] to 20 [mg / cm ³ ], more preferably 12.5 [mg / cm ³ ] to 20 [mg / It has the same configuration as that of the metal halide lamp 1 with a rated power of 150 [W], which is the first embodiment of the present invention, except that it is defined within the range of cm ³ ]. Therefore, the configuration of the metal halide lamp according to the second embodiment of the present invention is the same as described above except for the above differences, and the details thereof are omitted.

Here, the reason why the metal halide is mainly (for example, 95 [wt%] or more) metal iodide and the total encapsulated amount is specified to be 10.5 [mg / cm ³ ] or more will be described.

  First, it is not necessary for all metal halides to be in the form of iodide, and some of them may be in the form of bromide. However, as described above, this type of metal halide lamp should be lit at a high load. In consideration of the above, it is preferable to encapsulate mainly 95 [wt%] or more in the form of metal iodide.

Next, in Example a shown in Table 1, without changing the composition ratio of the luminescent material, only the total encapsulated amount of the metal halide to be encapsulated (here, all are metal iodide) is shown in Table 2. As shown, lamps varied in the range of 10.5 [mg / cm ³ ] to 20.5 [mg / cm ³ ] were produced one by one. Then, each of the produced lamps is placed in a vertical position so that the cap 6 faces upward, and is lit naked at the rated power (150 [W]), and the special color rendering index R ₉ and the lamp efficiency after 100 hours of lighting have elapsed. When [lm / W] was examined, the results shown in Table 2 were obtained.

In addition, the total enclosed amount in Example c is 10.5 [mg / cm ³ ], the total enclosed amount in Example d is 11.0 [mg / cm ³ ], and the total enclosed amount in Example e is 12.5 [mg / cm ³ ]. mg / cm ³ ], the total enclosed amount in Example f is 18.0 [mg / cm ³ ], the total enclosed amount in Example g is 20.0 [mg / cm ³ ], and the total enclosed amount in Example h is 20.5 [mg / cm ³ ].

Also, including Example a, the total amount of metal iodide and the special color rendering index R ₉ based on Examples c, d, e, f, g and h The relationship is shown in FIG.

As is clear from Table 2 and FIG. 4, when the total enclosed amount is 10.5 [mg / cm ³ ] or more, the special color rendering index R ₉ is markedly increased. Specifically, Example c and Example In the case of d, Example e, Example f, Example g and Example h, a special color rendering index R ₉ of 65 or more is obtained, which is compared with the special color rendering index R ₉ (10) of the conventional ceramic metal halide lamp. As a result, it was found that an even higher color rendering was obtained. Therefore, in order to obtain a higher color rendering than the color rendering of the conventional ceramic metal halide lamp, it was found that the total amount of metal iodide to be enclosed should be specified to be 10.5 [mg / cm ³ ] or more. .

On the other hand, when the total enclosed amount exceeds 20.0 [mg / cm ³ ], for example, in the case of Example h, the special color rendering index R ₉ far exceeds the special color rendering index R ₉ of the conventional ceramic metal halide lamp. The lamp efficiency (95 [lm / W]) was found to be lower than the lamp efficiency (96 [lm / W]) of Example a. Therefore, in consideration of a practical range for obtaining a higher color rendering performance than that of a conventional ceramic metal halide lamp and higher lamp rendering efficiency, a total of metal iodides is considered. it was found preferable to define the filling amount in the range of ^{10.5 [mg / cm 3] ~20.0} [mg / cm 3]. ^Furthermore, it was found to be preferable to define the range of 12.5 [mg / cm 3] ~20.0 [mg / cm 3].

  In Example e, the color temperature after lighting for 100 hours was 3480 [K], the average color rendering index Ra was 94.5, DUV was −7, and the luminous flux was 14700 [lm].

  Further, in the above experiment, all the luminescent materials were encapsulated in the form of metal iodide, but the range of conditions in which the total encapsulated amount of metal iodide was 95 [wt%] or more (not including 100 [wt%]). In particular, it was found that the same results as described above were obtained even when some or all of the luminescent materials were encapsulated in the form of bromide. In the above experiment, only cerium is used as the rare earth metal consisting of group B. However, praseodymium may be used in place of cerium, or praseodymium in addition to cerium may be used within the above composition ratio range. It was found that the same result as above was obtained. Further, as the light emitting substance, for example, neodymium (Nd), terbium (Tb), lutetium (Lu), lithium (Li), barium (Ba), strontium (Sr) or the like may be encapsulated in addition to the above-described metals. .

Here, in each of Example c, Example d, Example e, Example f, Example g, and Example h, light emission when the lamp is turned on in a vertical position so that the base 6 faces upward. When the inner surface of the tube 4 was observed, as shown in FIG. 5, a substance 28 considered to be a liquefied metal halide adhered to the inner surface of the lower hemispherical portion 14 in the main tube portion 10 in the form of a thin film. I found out. Such a phenomenon is not observed when the total amount of metal halide enclosed is small as in Example a, and a plurality of parts as shown in FIG. 3 are integrated by shrink fitting or the like. Even when 10.5 [mg / cm ³ ] or more was enclosed in the arc tube 18 having a total enclosed amount, it was not observed. By defining the total amount of the enclosed metal halide as described above from this to 10.5 [mg / cm ^3] or more, the special color rendering index of the special color rendering index R ₉ is a conventional ceramic metal halide lamp R ₉ The reason why the color rendering property is remarkably increased and higher color rendering properties can be obtained can be considered as follows.

When the envelope 12 of the arc tube 4 is formed by integral molding, in order to reduce the heat conduction loss of the arc tube 4 as described above, the temperature of the narrow tube portion 11 particularly in the envelope 20 shown in FIG. Since the temperature is higher than the temperature of the narrow tube portion 19, the metal halide is less likely to sink into the narrow tube portion 11, and as a result, a liquid is formed on the inner surface of the lower hemisphere portion 14 in the main tube portion 10. Metal halide (substance 28) is considered to have adhered. Since the temperature of the inner surface of the hemispherical portion 14 is higher than the temperature of the inner surface of the narrow tube portion 11, the vapor pressure of the luminescent material is considerably increased because the liquefied metal halide adheres to the inner surface of the hemispherical portion 14. It is thought that there is. In addition to this, since the total amount of encapsulated material is increased, it is considered that the vapor pressure of the luminescent material is remarkably increased. The result of the vapor pressure of the luminescent material is remarkably increased as the spectral distribution is shifted to the long wavelength side, the special color rendering index R ₉ is considered to have significantly increased.

  On the other hand, as described above, when the spectral distribution is shifted to the longer wavelength side, the lamp efficiency tends to deviate from the specific luminous efficiency curve. However, as shown in Table 2, each of Example c, Example d, Example e, Example f, Example g, and Example h has a high lamp efficiency because the total amount of metal halide enclosed is increased. It is considered that the increase in the vapor pressure of the luminescent material caused the increase, the vapor partial pressure of cerium (praseodymium) having a particularly high luminous efficiency increased, and the lamp efficiency increased.

As described above, according to the configuration of the metal halide lamp according to the second embodiment of the present invention, the envelope 12 of the arc tube 4 is formed by integral molding, and the luminescent material is enclosed in the form of a metal halide. The metal halide is mainly metal iodide, and the total encapsulated amount is defined as 10.5 [mg / cm ³ ] or more, so that the color temperature is 2800 [K] to 3700 [K]. Thus, it is possible to obtain a higher color rendering property while maintaining a sufficiently high lamp efficiency as compared with the lamp efficiency and the color rendering property of the conventional ceramic metal halide lamp.

  In the second embodiment, the metal halide lamp having a rated power of 150 [W] is described as an example. However, the second embodiment can be applied to a metal halide lamp having a rated power of, for example, 20 [W] to 300 [W]. Is.

Even if the shape of the envelope is different from the shape of the envelope 12, the envelope is formed by integral molding, and the luminescent material is enclosed in the form of a metal halide. As long as the metal halide is mainly metal iodide and the total encapsulated amount is defined to be 10.5 [mg / cm ³ ] or more, the same effect as described above can be obtained.

  Next, as shown in FIG. 6, an illumination device according to a third embodiment of the present invention is an illumination device used as a downlight incorporated in a ceiling, for example, and is an umbrella incorporated in a ceiling 29. And a lighting fixture 33 having a plate-like base portion 31 attached to the bottom of the reflecting lamp 30 and a socket portion 32 provided at the bottom of the reflecting lamp 30, and the lighting fixture 33. A metal halide lamp 1 with a rated power of 150 [W], which is a first embodiment of the present invention, attached to the socket part 32, and a lighting circuit 34 attached to a position away from the reflecting lamp 30 of the base part 31. I have.

  The lighting circuit 34 is a known electronic ballast or a known copper iron ballast.

  As described above, according to the configuration of the lighting apparatus according to the third embodiment of the present invention, since the metal halide lamp 1 according to the first embodiment of the present invention described above is used, the color temperature is 2800 [ K] to 3700 [K], and an extremely high color rendering and highly efficient lighting device can be realized.

  In the third embodiment, ceiling lighting is given as an example of downlight as an application of the lighting device, but it can also be used for other indoor lighting, store lighting, etc., and its use is limited. It is not something. Various known lighting fixtures and ballasts can be used depending on the application.

  In the third embodiment, the case where the metal halide lamp 1 having a rated power of 150 [W], which is the first embodiment of the present invention, has been described. However, the second embodiment of the present invention is described. Even when a metal halide lamp with a rated power of 150 [W] is used, the same effect as described above can be obtained.

  The present invention can also be applied to a metal halide lamp having a color temperature of 2800 [K] to 3700 [K] and requiring high color rendering and high lamp efficiency.

  The present invention can also be applied to a lighting device having a color temperature of 2800 [K] to 3700 [K], which requires high color rendering and high efficiency.

Partially cutaway front view of a metal halide lamp according to the first and second embodiments of the present invention Front sectional view of arc tube used in metal halide lamp Front cross-sectional view of an arc tube that can be used in the metal halide lamp that is the first embodiment of the present invention, and an arc tube that is used in a conventional ceramic metal halide lamp Diagram showing the relationship between the total amount of enclosed luminescent material and special color rendering index R ₉ The principal part expanded sectional view of the arc_tube | light_emitting_tube used for the metal halide lamp which is the 2nd Embodiment of this invention. The figure which showed typically the illuminating device which is the 3rd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal halide lamp 2 Stem 3 Outer tube 4,18 Light emission tube 5 Sleeve 6 Cap 6a Eyelet part 6b Shell part 7 Power supply line 8 External lead part 9 Discharge space 10, 17 Main pipe part 11, 19 Narrow pipe part 12, 20 Enclosure Vessel 13, 15 Cylindrical part 14 Hemispherical part 16 Closed part 16a Through hole 21 Electrode body 22 Electrode part 23 Internal lead part 24 Sealing material 25 Electrode rod 26 Electrode coil 27 Coil 28 Material 29 Ceiling 30 Reflective lamp 31 Base part 32 Socket part 33 Lighting equipment 34 Lighting circuit

Claims (3)

A metal halide lamp having a color temperature of 2800 [K] to 3700 [K] having a ceramic arc tube in which an electrode body is arranged and a luminescent material is enclosed,
The luminescent material includes at least a rare earth metal, sodium (Na) and calcium (Ca), and the rare earth metal includes at least one of dysprosium (Dy), thulium (Tm) and holmium (Ho), and cerium (Ce). And at least one of praseodymium (Pr),
Among the rare earth metals, the composition ratio of the group A consisting of at least one of dysprosium, thulium and holmium is M _A [mol%], and among the rare earth metals, the composition of the group B consisting of at least one of cerium and praseodymium. When the composition ratio is M _B [mol%], the sodium composition ratio is M _Na [mol%], and the calcium composition ratio is M _Ca [mol%], M _A is 2 [mol%] to 10 [ mol%], M _B is 0.5 [mol%] ~4 [mol %], M Na is 35 [mol%] ~45 [mol %], M Ca is 40 [mol%] ~60 [mol %] A metal halide lamp characterized by The envelope of the arc tube is formed by integral molding,
The luminescent material is encapsulated in the form of a metal halide,
2. The metal halide lamp according to claim 1, wherein the metal halide is mainly metal iodide, and a total amount of the metal halide is 10.5 [mg / cm ³ ] or more. An illumination device comprising: the metal halide lamp according to claim 1 or 2; a lighting circuit for lighting the metal halide lamp; and a lighting fixture in which the metal halide lamp is incorporated.

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