TW202025224A - Metal halide lamp and ultraviolet ray irradiation device ensures required illuminance characteristics while suppressing deterioration - Google Patents

Abstract

The invention can ensure illuminance characteristics while suppressing deterioration. In the implementation, a metal halide lamp comprises a light emitting tube and an electrode. In the light emitting tube, halogen, iron and thallium are enclosed. The electrode is disposed inside the light emitting tube. The enclosed quantity for thallium relative to iron is above 0.2 and below 0.3 in terms of mass ratio.

Description

Metal halide lamp and ultraviolet irradiation device

The embodiment of the present invention relates to a metal halide lamp and an ultraviolet irradiation device.

For example, in the semiconductor exposure process, ultraviolet (ultraviolet, UV) ink (ink) or UV coating drying process, resin curing process, etc., in order to carry out a photochemical reaction by ultraviolet rays, a metal halide lamp is used as the emission of ultraviolet rays. Light source. [Prior Art Literature] [Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 6-275234

[The problem to be solved by the invention]

In a metal halide lamp, sometimes the arc tube is deteriorated due to blackening, resulting in a decrease in the ultraviolet transmittance of the arc tube. In addition, if the composition of the metal or halogen enclosed in the arc tube is changed in order to suppress the blackening of the arc tube, the luminous intensity may decrease and the desired illuminance may not be obtained. In this way, there is room for improvement in terms of both suppressing deterioration and ensuring the required illuminance characteristics.

The problem to be solved by the present invention is to provide a metal halide lamp and an ultraviolet irradiation device that can suppress degradation and ensure the required illuminance characteristics. [Technical means to solve the problem]

The metal halide lamp of the embodiment includes an arc tube and an electrode. In the arc tube, halogen, iron and thallium (thallium) are enclosed. The electrodes are arranged inside the arc tube. The enclosed amount of thallium to iron is 0.2 or more and 0.3 or less in terms of mass ratio. [Effects of the invention]

According to the present invention, deterioration can be suppressed while ensuring the required illuminance characteristics.

The metal halide lamp 10 of the embodiment described below includes an arc tube 11 and an electrode 14. In the arc tube 11, halogen, iron, and thallium are enclosed. The electrode 14 is provided inside the arc tube 11. The enclosed amount of thallium to iron is 0.2 or more and 0.3 or less in terms of mass ratio.

In addition, the enclosed amount of thallium in the embodiment described below is 0.0050 [mg] or more and 0.0076 [mg] or less in terms of 1 [cm ³ ] per unit volume of the arc tube 11.

In addition, the thallium of the embodiment described below is enclosed in the arc tube 11 as thallium iodide that is 0.008 [mg] or more and 0.012 [mg] or less per unit volume 1 [cm ³ ] of the arc tube 11.

In addition, the enclosed amount of iron in the embodiment described below is 0.010 [mg] or more and 0.040 [mg] or less in terms of 1 [cm ³ ] per unit volume of the arc tube 11.

Furthermore, in the metal halide lamp 10 of the embodiment described below, the uniformity of the light irradiated from the arc tube 11 is 5 [%] or less.

Furthermore, in the metal halide lamp 10 of the embodiment described below, the relative illumination in the tube axis direction of the arc tube 11 is 90 [%] or more.

In addition, in the metal halide lamp 10 of the embodiment described below, the surface temperature of the arc tube 11 during lighting is 760 [° C.] or more and 850 [° C.] or less.

Furthermore, the ultraviolet irradiation device 100 of the embodiment described below includes a metal halide lamp 10 and a mounting portion 20. The mounting part 20 mounts the metal halide lamp 10.

Hereinafter, embodiments of the present invention will be described based on the drawings. In addition, each embodiment shown below does not limit the technique disclosed by this invention. In addition, each embodiment and each modification shown below can be appropriately combined within a range that does not contradict each other. In the description of the respective embodiments, the same reference numerals are given to the same configuration, and the following description is appropriately omitted. [Implementation]

First, a configuration example of the metal halide lamp and the ultraviolet irradiation device according to the embodiment will be described using FIG. 1. Fig. 1 is a side view of an ultraviolet irradiation device according to an embodiment. The ultraviolet irradiation device 100 shown in FIG. 1 has a metal halide lamp 10 and a lamp 30. The lamp 30 has an attachment portion 20, a wind shield 31, and an exhaust port 32, and is configured, for example, such that the ultraviolet irradiation device 100 is installed at a predetermined position such as a ceiling. The ultraviolet irradiation device 100 shown in FIG. 1 can be used, for example, in a semiconductor exposure process, a drying process of an ultraviolet curable ink or an ultraviolet curable paint, a curing process of an ultraviolet curable resin, and the like in a process of performing a photochemical reaction by ultraviolet rays.

The mounting part 20 mounts the metal halide lamp 10 detachably. The attachment portion 20 has a holding member (not shown) that holds a base member 13 described later that the metal halide lamp 10 has. The holding member is formed of a conductive metal material, and is electrically connected to a power supply device not shown. The holding member supplies electric power to the metal halide lamp 10 via an external lead 17 described later. Furthermore, in order to improve the heat dissipation of the base member 13, the holding member may be formed of a material with high thermal conductivity.

The windshield 31 is arranged above the mounting portion 20, and by dissipating the air heated by the heat of the metal halide lamp 10 to the exhaust port 32 side, it suppresses the overheating of the metal halide lamp 10, which will be described later. The blackening of the luminous tube 11. A plurality of wind shields 31 are arranged along the tube axis direction of the metal halide lamp 10.

The exhaust port 32 is an opening provided in the upper part of the lamp 30. The exhaust port 32 is connected to an external exhaust blower (not shown). The exhaust port 32 forcibly exhausts the air heated by the heat generated by the lighting metal halide lamp 10 from the mounting portion 20, thereby suppressing problems caused by overheating of the metal halide lamp 10.

The angle of each windshield 31 with respect to the metal halide lamp 10 or the exhaust port 32 is arranged so that the surface temperature of the arc tube 11 of the metal halide lamp 10 that is lighting is within a predetermined range, for example, 760 [°C] Above and below 850[°C]. In addition, a fan may be provided at a position facing the wind shield 31 and the exhaust port 32 with the metal halide lamp 10 sandwiched therebetween to blow air toward the metal halide lamp 10. In addition, the wind shield 31 and the exhaust port 32 are an example of a cooling mechanism that cools the metal halide lamp 10 attached to the mounting portion 20, and they may not necessarily have the structure shown in the figure.

(Structure of metal halide lamp) As shown in FIG. 1, the metal halide lamp 10 of the embodiment includes an arc tube 11, a sealing portion 12, a base member 13, an electrode 14, a metal foil 15, an inner lead 16 and an outer lead 17.

The arc tube 11 is formed in a tube shape, and is sealed by sealing portions 12 provided at both ends in the tube axis direction. The arc tube 11 is, for example, quartz glass, and transmits ultraviolet rays. Furthermore, the arc tube 11 has a space 11a inside, and at least a metal halide, iron, and mercury are enclosed in the space 11a. As the metal halide enclosed in the space 11a, for example, thallium iodide (TlI) is used. If thallium, which has a higher vapor pressure than iron, is enclosed in the arc tube 11, there is an effect that the thallium vaporized near the inner wall of the arc tube 11 acts as a buffer during the lighting of the metal halide lamp 10 The role of the material to inhibit the adhesion or penetration of iron to the arc tube 11. In addition, as the halogen of the metal halide enclosed in the space 11a, for example, chlorine, bromine, etc. may be used. In addition, the details of the components and the enclosed amount of the enclosed material in the enclosed space 11a will be described later.

The sealing part 12 is formed in a cylindrical shape by shrink sealing. In addition, the sealing portion 12 may be formed in a plate shape by pinch sealing.

The base members 13 are respectively arranged so as to cover the outer periphery of the sealing portion 12 formed at both ends of the arc tube 11 in the tube axis direction, and support the arc tube 11.

The electrodes 14 are arranged in the space 11a so as to face each other at a predetermined interval L1 in the tube axis direction. The electrode 14 is one end of the inner lead 16, and the other end of the inner lead 16 is electrically connected to the metal foil 15. The electrode 14 is, for example, a thoriated tungsten containing thorium oxide as an electron radioactive substance. The inner lead 16 is integrally formed of, for example, the same thoriated tungsten plated as the electrode 14. In addition, the electrode 14 or the internal lead 16 is not limited to the above. For example, the internal lead 16 may be formed separately from the electrode 14, for example, tungsten doped with potassium or silicon doped with tungsten.

One end of the metal foil 15 is connected to the inner lead 16 and the other end is connected to the outer lead 17. The metal foil 15 is embedded in the inside of the sealing part 12, respectively. The metal foil 15 is, for example, a molybdenum foil.

The external lead 17 connects the metal foil 15 to an external power supply device not shown. The external lead 17 is, for example, a molybdenum rod. One end of the external lead 17 is connected to the metal foil 15 respectively, and the other end is exposed to the outside of the arc tube 11. The other end of the external lead 17 is electrically connected to a cable (not shown) via a connector (not shown). That is, the metal halide lamp 10 of the embodiment corresponds to the power supply from the power supply device to the electrode 14 via the connector, cable, external lead 17, metal foil 15, and internal lead 16 connected to an external power supply device not shown. Electricity discharges to emit ultraviolet light.

(The amount of iron and thallium enclosed in the arc tube) Fig. 2 is a graph showing the results of comparing the 365 nm phase contrast with the amount of thallium iodide enclosed. In addition, as the metal halide lamp 10, a luminous tube diameter of 26 [mm], a wall thickness of 1.5 [mm], a luminous length L1 (refer to Fig. 1) 1200 [mm], and a total length L2 (refer to Fig. 1) of 1300 [mm] . In addition, unless otherwise specified, the same metal halide lamp 10 is also used in the description after FIG. 3.

Further, for the enclosed per unit space 11a volume 1 [cm ^3] calculated as 0.025 [mg] of the iron, and thus is enclosed per unit space 11a volume 1 [cm ^3] calculated as 0.004 [mg], 0.008 [ mg], 0.012[mg], 0.018[mg] thallium iodide metal halide lamp 10, when the surface temperature of the arc tube 11 is 800[℃], the wavelength when lit with the lamp power of 18000[Wrms] is measured 365 The illuminance in [nm] is standardized with the actual measurement value at TlI0.004 [mg/cm ³ ] as 100 [%]. Here, the "surface temperature of the arc tube 11" refers to a value based on the situation where the arc column is located on the upper side by the convection of the vapor in the tube while the lamp is on. The tube wall temperature is the value obtained by measuring. The tube wall temperature on the upper surface of the arc tube is measured by a K thermocouple, for example. In addition, the illuminance is that a sensor (manufactured by ORC Manufacturing Co., Ltd.: UV-SD35-M10), measured using an illuminance meter (ORC Manufacturing Co., Ltd.: UV-M03A).

As shown in Fig. 2, when the enclosed thallium iodide amount is 0.018 [mg/cm ³ ], the relative strength is as low as 90 [%], and the required illuminance characteristics cannot be ensured. In contrast, in the metal halide lamp 10 in which the enclosed thallium iodide amount is 0.012 [mg/cm ³ ] or less, the relative intensity exhibits a high value of 95 [%] or more. That is, it is shown that by setting the enclosed amount of thallium iodide to 0.012 [mg/cm ³ ] or less, the required illuminance characteristics can be secured.

Fig. 3 is a graph showing the result of comparing the relationship between the temperature of the arc tube and the illuminance at 365 nm for each type of thallium iodide enclosed amount. 3 is a graph enclosed per unit space 11a volume 1 [cm ^3] calculated as 0.025 [mg] of the iron, and thus are enclosed per unit space 11a volume 1 [cm ^3] calculated as 0.012 [mg], The metal halide lamp 10 of thallium iodide of 0.008[mg] and 0.004[mg] is measured at the surface temperature of the arc tube 11 at 765[℃], 773[℃], 780[℃], 800[℃] The illuminance at a wavelength of 365 [nm] when the lamp power is 18000 [Wrms] is used for lighting, and the actual measurement value at the surface temperature of the arc tube 11 at 800 [°C] is normalized as 100 [%], and the figure is shown.

As shown in FIG. 3, as the surface temperature of the arc tube 11 decreases, the illuminance also decreases. In particular, in the metal halide lamp 10 containing 0.004 [mg/cm ³ ] thallium iodide, the illuminance at the surface temperature of the arc tube 11 at 765 [°C] drops to about 85 [%] (85.8 [%]) .

Next, the influence of the enclosed amount of thallium on the luminescence intensity of iron will be explained using FIGS. 4 to 6. 4 to 6 are graphs showing the results of comparison of the spectral distribution when the amount of thallium iodide enclosed is changed in accordance with the surface temperature of each arc tube. As with Figures 2 and 3, when the surface temperature of the arc tube 11 is 800 [℃] and 765 [℃], the enclosed amount of iron is measured and fixed to 0.025 [mg/cm ³ ]. On the other hand, the iodide is The amount of thallium enclosed is the spectral distribution of the metal halide lamp 10 of 0.012 [mg/cm ³ ] (Figure 4), 0.008 [mg/cm ³ ] (Figure 5), and 0.004 [mg/cm ³ ] (Figure 6). In addition, regarding the spectral distribution, the MCPD-9800 (Otsuka Electronics Co., Ltd.) is used at a position spaced 1 [m] away from the surface of the arc tube 11 located at the center of the tube axis of the arc tube 11 in the radial direction of the arc tube 11. Co., Ltd.) and the measured value is standardized by setting the spectrum value of 375 [nm], which is the luminescence line of iron, to 100 [%]. Furthermore, the amount of thallium iodide enclosed is 0.004 [mg/cm ³ ], the illuminance value measured under the condition of the surface temperature of the arc tube 11 at 800 [°C] is used as a reference to multiply each spectrum data to standardize and graph it, so that it can be compared with those shown in FIGS. 4 to 6 The illuminance values are directly compared.

As shown in Figure 5 and Figure 6, when the enclosed thallium iodide amount is 0.008 [mg/cm ³ ] and 0.004 [mg/cm ³ ], the main luminescence, that is, the glow line derived from iron (wavelength 375 [nm ], 383[nm]) in a state of high relative intensity. In particular, when the enclosed thallium iodide amount is 0.004 [mg/cm ³ ], the enclosed thallium iodide amount is insufficient, and it is difficult to suppress the blackening of the arc tube 11. On the other hand, as shown in Figure 4, when the amount of thallium iodide enclosed is 0.012 [mg/cm ³ ], the relative intensity of the glow line (wavelength 353 [nm], 378 [nm]) derived from thallium is comparable to Compared with, the relative strength of the glow wire derived from iron is lower. In this way, if the amount of thallium iodide enclosed is excessively increased, the luminous efficiency of iron decreases, and the illuminance of 365 [nm], which is an index of the intensity of ultraviolet light, decreases. The decrease in the luminous efficiency of the iron becomes more remarkable when the surface temperature of the arc tube 11 is high at 800 [°C].

Next, the influence of the enclosed amount of thallium on the uniformity of light irradiated from the arc tube will be explained using FIGS. 7 to 9. Fig. 7 is a graph showing the result of comparing the surface temperature of the arc tube at each measurement point. Fig. 8 is a graph showing the result of comparing the UV-35 illuminance at each measurement point for each type of thallium iodide enclosed amount. In addition, in FIG. 7, the enclosed amount of iron and the enclosed amount of thallium iodide were measured as 0.025 [mg/cm ³ ] and 0.012 [mg/cm ³ ], respectively. In addition, in Fig. 8, the enclosed amount of iron is fixed to 0.025 [mg/cm ³ ], while the enclosed amount of thallium iodide is set to 0.012 [mg/cm ³ ] and 0.008 [mg/cm ³ ]. , 0.004 [mg/cm ³ ] metal halide lamp 10, and perform the measurement.

In FIGS. 7 and 8, for the "measurement point [mm]", the center of the tube axis direction of the arc tube 11 with the light emission length L1=1200 [mm] is defined as 600 [mm], and the distance along the arc tube 11 The positions separated by 300 [mm] in the pipe axis direction are respectively specified as 300 [mm] and 900 [mm]. In addition, in Fig. 8, the "UV-35 illuminance" refers to the use of a sensor (manufactured by ORC Manufacturing Co., Ltd.: UV-SD35-M10) and an illuminance meter with a sensitivity curve at a wavelength of 310 [nm] to 700 [nm] (ORC Manufacturing Co., Ltd.: UV-M03A) and measured the obtained value. In addition, in FIG. 7, the surface temperature at each measurement point (300 [mm], 600 [mm], 900 [mm]) is illustrated. In FIG. 8, the Sensors (UV-SD35-M10, manufactured by ORC Manufacturing Co., Ltd.) are arranged at positions separated by 1 [m] in the radial direction of the arc tube 11, and an illuminance meter (manufactured by ORC Manufacturing Co., Ltd.: UV-M03A) is used. The measured UV-35 illuminance value is normalized and graphed with the value at the measurement point 600 [mm] as 100 [%].

As shown in FIG. 7, it can be seen that the surface temperature of the arc tube 11 is highest in the central part (600 [mm]), and becomes lower as it moves away from the central part in the tube axis direction. Furthermore, in the example shown in FIG. 7, the surface temperature of the arc tube 11 at the measurement points 300 [mm] and 900 [mm] differs according to environmental conditions, as shown in FIG. 8, following the difference in the surface temperature , UV-35 illumination is also different. In particular, when the enclosed thallium iodide amount is 0.004 [mg/cm ³ ], the influence of the surface temperature of the arc tube 11 on the UV-35 illuminance becomes significant.

Fig. 9 is a graph showing the results of comparing the uniformity for each type of thallium iodide enclosed amount. In Fig. 9, "uniformity [%]" is calculated as (maximum illuminance-minimum illuminance)/(maximum illuminance + minimum illuminance)×100. Taking a case where the amount of thallium iodide enclosed is 0.004 [mg/cm ³ ] as an example, it is (100-85.8)/(100+85.8)=7.64[%].

The uniformity of the light irradiated from the arc tube 11 is a value used as an index for judging the unevenness of the irradiation of ultraviolet light with respect to the irradiated surface, and can be set to 5 [%] or less.

Moreover, as another index for determining the unevenness of the irradiation of ultraviolet light with respect to the irradiated surface, the relative illuminance in the tube axis direction of the arc tube 11 can be used. Here, the "relative illuminance in the tube axis direction of the arc tube 11" refers to the value of the center (600 [mm]) of the tube axis direction of the arc tube 11 as 100 [%] as shown in FIG. The minimum value of relative illuminance at each measurement point when the value of UV-35 illuminance is normalized. In the metal halide lamp 10 in which the relative illuminance in the tube axis direction of the arc tube 11 is 90 [%] or more, there is little unevenness in the irradiation of ultraviolet light to the irradiated surface, and it can be said that it is suitable for practical use.

Based on the aforementioned experimental results, the following results were obtained. That is, in the metal halide lamp 10, it is desirable that the thallium iodide enclosed in the arc tube 11 is 1 [cm ³ ] per unit volume of the arc tube 11 It is 0.008 [mg] or more and 0.012 [mg] or less. By enclosing an appropriate amount of thallium iodide into the arc tube 11 in this way, deterioration can be suppressed and the required illuminance characteristics can be ensured.

In addition, in the above embodiment, an example is shown in which thallium iodide is enclosed as a metal halide, but it is not limited to this, as long as the enclosure is 0.005 [mg] or more per unit volume 1 [cm ³ ] of the arc tube 11 Thallium less than 0.0076 [mg] is sufficient.

In addition, in the above-mentioned embodiment, the enclosed amount of iron is fixed to 0.025 [mg/cm ³ ], but it is not limited to this, as long as the enclosed amount is calculated as 1 [cm ³ ] per unit volume of the arc tube 11 Iron of 0.010 [mg] or more and 0.040 [mg] or less is sufficient. At this time, by setting the enclosed amount of thallium with respect to iron to be 0.2 or more and 0.3 or less in terms of mass ratio, deterioration can be suppressed and the required illuminance characteristics can be ensured.

As described above, the metal halide lamp 10 of the embodiment includes the arc tube 11 and the electrode 14. In the arc tube 11, halogen, iron, and thallium are enclosed. The electrode 14 is provided inside the arc tube 11. The enclosed amount of thallium to iron is 0.2 or more and 0.3 or less in terms of mass ratio. As a result, the deterioration of the arc tube 11 can be suppressed, and the required illuminance characteristics can be ensured.

Furthermore, in the metal halide lamp 10 of the embodiment, the uniformity of the light irradiated from the arc tube 11 is 5 [%] or less. Thereby, it is possible to reduce the unevenness in the irradiation of ultraviolet light with respect to the irradiated surface.

In addition, in the metal halide lamp 10 of the embodiment, the relative illuminance in the tube axis direction of the arc tube 11 is 90 [%] or more. Thereby, it is possible to reduce the unevenness in the irradiation of ultraviolet light with respect to the irradiated surface.

Furthermore, in the metal halide lamp 10 of the embodiment, the surface temperature of the arc tube 11 during lighting is 760 [°C] or more and 850 [°C] or less. Thereby, it is possible to reduce the unevenness in the irradiation of ultraviolet light with respect to the irradiated surface.

Furthermore, the ultraviolet irradiation device 100 of the embodiment includes a metal halide lamp 10 and a mounting part 20. The mounting part 20 mounts the metal halide lamp 10. As a result, the deterioration of the arc tube 11 can be suppressed, and the required illuminance characteristics can be ensured. Furthermore, it is possible to reduce the unevenness in the irradiation of ultraviolet light with respect to the irradiated surface.

The embodiments of the present invention have been described, but the embodiments are only examples and are not intended to limit the scope of the invention. These embodiments can be implemented in other various forms, and various omissions, substitutions, and changes can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope or spirit of the invention, and are also included in the invention described in the claims and their equivalent scope.

10: Metal halide lamp 11: luminous tube 11a: Space 12: Sealing part 13: Lamp holder components 14: Electrode 15: Metal foil 16: internal lead 17: External lead 20: Installation Department 30: lamps 31: Windshield 32: exhaust port 100: Ultraviolet irradiation device L1: Specified interval, long light emission L2: Full length

Fig. 1 is a side view of an ultraviolet irradiation device according to an embodiment. Fig. 2 is a graph showing the results of comparing the 365 nm phase contrast with the amount of thallium iodide enclosed. Fig. 3 is a graph showing the result of comparing the relationship between the temperature of the arc tube and the illuminance at 365 nm for each type of thallium iodide enclosed amount. Fig. 4 is a graph showing the results of comparing the spectral distributions when the amount of thallium iodide enclosed is changed for each type of arc tube surface temperature. Fig. 5 is a graph showing the results of comparing the spectral distributions when the amount of thallium iodide enclosed is changed for each type of arc tube surface temperature. Fig. 6 is a graph showing the results of comparing the spectral distributions when the amount of thallium iodide enclosed is changed for each type of arc tube surface temperature. Fig. 7 is a graph showing the result of comparing the surface temperature of the arc tube at each measurement point. Fig. 8 is a graph showing the result of comparing the UV-35 illuminance at each measurement point for each type of thallium iodide enclosed amount. Fig. 9 is a graph showing the results of comparing the uniformity for each type of thallium iodide enclosed amount.

10: Metal halide lamp

11: luminous tube

11a: Space

12: Sealing part

13: Lamp holder components

14: Electrode

15: Metal foil

16: internal lead

17: External lead

20: Installation Department

30: lamps

31: Windshield

32: exhaust port

100: Ultraviolet irradiation device

L1: Specified interval, long light emission

L2: Full length

Claims (8)

A metal halide lamp, which includes: Light emitting tube, sealed with halogen, iron and thallium; and The electrodes are arranged inside the luminous tube, The enclosed amount of the thallium with respect to the iron is 0.2 or more and 0.3 or less in terms of mass ratio. The metal halide lamp described in the first item of the scope of patent application, wherein the enclosed amount of the thallium is 0.005 [mg] or more and 0.0076 [mg] or less per unit volume 1 [cm ³ ] of the arc tube. The metal halide lamp as described in item 1 or item 2 of the scope of patent application, wherein the thallium is calculated as 0.008 [mg] or more and 0.012 [mg per unit volume 1 [cm ³ ] of the arc tube ] The following thallium iodide is enclosed in the arc tube. The metal halide lamp described in item 1 or item 2 of the scope of patent application, wherein the enclosed amount of iron is 0.010 [mg] or more and 0.040 [in terms of 1 [cm ³ ] per unit volume of the arc tube mg] or less. Such as the metal halide lamp described in item 1 or item 2 of the scope of patent application, wherein The uniformity of the light irradiated from the arc tube is 5 [%] or less. Such as the metal halide lamp described in item 1 or item 2 of the scope of patent application, wherein The relative illuminance in the tube axis direction of the luminous tube is 90 [%] or more. Such as the metal halide lamp described in item 1 or item 2 of the scope of patent application, wherein The surface temperature of the arc tube during lighting is 760 [°C] or more and 850 [°C] or less. An ultraviolet irradiation device, which includes: The metal halide lamp described in any one of items 1 to 7 of the scope of patent application; and The installation part installs the metal halide lamp.

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