KR20080040570A - Ultraviolet discharge lamp - Google Patents

Abstract

An ultraviolet discharge lamp is provided to improve light emitting efficiency by using mercury and halogenated thallium in a light emitting tube. An ultraviolet discharge lamp includes mercury and halogenated thallium instead of Fe as a discharge medium within a light emitting tube. The amount of halogenated thallium M is 0.01mg/cc<=M<=0.3mg/cc, when an inside diameter D of the light emitting tube is equal to or less than 30mm. In the inside diameter of the light emitting tube, the amount of mercury Hg is 0.9mg/cc<=Hg<=5.0mg/cc and the amount of halogenated thallium M is 0.012mg/cc<=M<=0.1mg/cc when a light emitting length L is 500mm<=L<=2500mm.

Description

UV discharge lamp {ULTRAVIOLET DISCHARGE LAMP}

The present invention relates to an ultraviolet discharge lamp.

Generally, the metal halide lamp of the ultraviolet light emission which has high luminescence intensity in the vicinity of 350-380 nm is effective for hardening an ultraviolet curable paint, and photoreaction to the functional polymer film with high market use recently.

However, it is known that the light of 340 nm or less light emission wavelength region deteriorates a functional material, and is used, suppressing these short wavelengths.

As described in Patent Literature 1, as described above, the metal thallium or thallium halide is sealed together with iron and mercury in an airtight container to suppress ultraviolet rays having a short wavelength of 340 nm or less and high near 365 nm. Ultraviolet irradiation lamps with luminous intensity are known.

However, in the conventional thallium halide lamp containing iron, the spectrum of 365 nm appears abruptly due to the presence of the iron element, but in reality, the spectrum of 365 nm as an integral value between the spectrum of the wavelength of 365 nm and its vicinity is obtained. As a matter of fact, the exact spectrum having a wavelength of 365 nm has not been sufficient. In addition, if the discharge is turned on for a long time, the iron element in the discharge medium reacts with the quartz glass of the hermetic container, causing devitrification, resulting in a decrease in luminescence intensity and also a problem in lowering luminance. In recent years, there has been a demand for a long (eg, 1800 mm) lamp capable of realizing uniform distribution of illuminance in the axial direction in a large film, printed matter, or the like represented by a large screen of a liquid crystal display device. However, in a halide thallium lamp containing iron, there is also a problem of lamp performance unsuitable for the demand for longening, such as separation light emission when the light emission length exceeds 300 mm.

[Patent Document 1] Japanese Patent Application Laid-Open No. 03-250549

This invention is made | formed in view of the subject of the prior art mentioned above, and an object of this invention is to provide the ultraviolet discharge lamp which can emit the ultraviolet light which has a small ultraviolet spectrum of 340 nm or less and has a high spectrum especially at 352 nm. .

The present invention also provides an ultraviolet discharge lamp that can be lengthened and can have a long life without causing spectral or illuminance deviation (separated light emission) in the lamp tube axis direction at high illumination. For the purpose of

One feature of the present invention is an ultraviolet discharge lamp containing no elemental iron as a discharge medium in a light emitting tube, and containing thallium halide with mercury.

In the ultraviolet discharge lamp, the sealing amount M of the thallium halide can be 0.01 mg / cc ≦ M ≦ 0.3 mg / cc when the inner diameter D ≦ 30 mm of the light emitting tube.

In the ultraviolet discharge lamp, when the inner diameter D of the light emitting tube is 30 mm and the emission length L is 500 mm ≤ L ≤ 2500 mm, the amount of Hg charged in the mercury is 0.9 mg / cc ≤ Hg ≤ 5.0 mg /. cc and the sealing amount M of thallium halide can be 0.012 mg / cc <= M <0.1mg / cc.

In the ultraviolet discharge lamp, the discharge medium of mercury and thallium halide contained in the light emitting tube has a potential hardness E (V / cm) at the time of stable lighting when the inner diameter D of the light emitting tube is D <30 mm. It can be set as the sealing amount whose value takes the value of 8 <E <30.

In the ultraviolet discharge lamp, the thallium halide may be thallium iodide (TlI).

In the ultraviolet discharge lamp, the thallium iodide (TlI) may have a weight ratio Mr = Hg (mg / cc) / TlI (mg / cc) to mercury (Hg) of 10 ≦ Mr ≦ 200.

According to the ultraviolet discharge lamp of the present invention, thallium halide is sealed together with mercury as a discharge medium in a lamp container and contains no iron element, thereby efficiently emitting ultraviolet light having a high spectrum at 352 nm, the emission wavelength of thallium. Can be. In addition, according to the ultraviolet discharge lamp of the present invention, the light can be emitted at high illuminance without occurrence of spectral or illuminance deviation in the lamp tube axis direction, and further a long service life can be achieved.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described in detail based on drawing.

(1st embodiment)

The ultraviolet discharge lamp of 1st Embodiment of this invention is demonstrated using FIG. In the ultraviolet (UV) discharge lamp 52 of the present embodiment, electrodes 521 and 522 made of tungsten (W) and the like are disposed inside an airtight container 520 that forms a quartz light emitting tube having ultraviolet ray permeability. The outer diameter of the tube 27.5 mm, the thickness 1.5 mm, the light emission length L is 1000 mm, the lamp voltage 1100 V, and the lamp current value 11.0 A.

Inside the hermetic container 520, a lean gas such as argon (Ar) gas, mercury, and thallium halide are sealed. As this thallium halide, thallium iodide (TlI) can be used. In the case of thallium iodide, as shown in FIG. 2, it has a big light emission peak in the vicinity of wavelength 352nm, 365nm, 378nm, especially near wavelength 352nm, 378nm. Instead of thallium iodide, thallium bromide may be employed.

Thallium (Tl) has a strong bright spectrum in the wavelength region of 352 nm, 365 nm, and 378 nm, and has an effect of reducing the luminescence intensity of mercury. Therefore, the mercury emission of 313 nm can be suppressed, and the ultraviolet-ray which made the light emission of the wavelength region of 340-400 nm relatively large can be emitted. Therefore, the ultraviolet discharge lamp 52 of this embodiment can reduce irradiation of the ultraviolet-ray of wavelength range 340nm or less which greatly affects the characteristic in the process with respect to an ultraviolet cured paint, functional plastics, etc ..

In the case of the inner diameter D ≦ 30 mm of the light emitting tube, the sealing amount of thallium halide is preferably set to an amount selected from 0.01 mg / cc ≦ M ≦ 0.3 mg / cc. More preferably, when the inner diameter D of the light emitting tube is D ≦ 30 mm and the light emission length L is 500 mm ≦ L ≦ 2500 mm, the amount of mercury Hg added is 0.9 mg / cc ≦ Hg ≦ 5.0 mg / cc, It is preferable to make loading amount M of thallium halide into the quantity chosen from 0.012 mg / cc <= M <= 0.1mg / cc.

When the amount M of encapsulation of thallium halide is M ≦ 0.3 mg / cc, uniform illuminance is obtained in the axial direction of the lamp 52, so that uniform irradiation of ultraviolet rays to the irradiated object can be realized. Moreover, as shown in the spectral characteristic of FIG. 2, since the peak value of the illuminance of wavelength 313nm which affects the characteristic of an irradiated object can be reduced to 5% or less compared with the peak value of the illuminance of wavelength 365nm, The characteristic of the irradiated object after ultraviolet irradiation can be improved more. On the other hand, when the encapsulation amount of thallium halide is 0.3 mg / cc or more, the thallium encapsulated in the airtight container 520 is unevenly dispersed in the longitudinal direction of the lamp 52, resulting in luminescence separation and deterioration in lamp performance. .

In addition, by the incorporation of thallium halide, generation of ultraviolet rays of the 313 nm peak which is ultraviolet rays by mercury can be suppressed, and the spectral intensity of the peak 313 nm can be suppressed to 5% or more relative to the spectral intensity of the peak 365 nm. As a result, the effect of deteriorating the irradiated object by irradiation with the irradiated object by the ultraviolet rays from the ultraviolet discharge lamp containing thallium halide mixed with the irradiated object can be more effectively performed.

In addition, in this embodiment, when the light emitting tube internal diameter D is D <30mm, the potential hardness E (V / cm) at the time of stable lighting can be set to 8 <E <30, and it does not become an overload, thereby long life And an ultraviolet lamp which effectively utilizes light emission of thallium.

In addition, when the inside diameter of an airtight container is 30 mm or less, and the input (W / cm) per unit length lights 60 W / cm or more, the encapsulation amount (mg / cc) of thallium iodide shall be 0.3 mg / cc or less. The emission intensity of the spectrum of 340 nm or less can be reduced thereby, and the emission intensity of the spectrum of 352 nm, 365 nm, and 378 nm can be improved.

As the tungsten material of the electrodes 521 and 522, cerium tungsten containing 0.5% or more of cerium oxide (Ce ₂ O ₃ ) can be used. Thorium tungsten, which is generally used as an electrode material, is a compound in which thorium oxide is stable but has radioactivity. Therefore, by including tungsten oxide having a work function close to this thorium oxide in tungsten, an electrode life equivalent to that of a thorium tungsten electrode can be obtained and the worry of adverse effects on the environment due to the radioactive material can be eliminated. In the graph of FIG. 3, the measurement result of the lifetime characteristic of the ultraviolet discharge lamp which employ | adopted the conventional thorium tungsten electrode, and the ultraviolet discharge lamp which employ | adopted the cerium tungsten electrode is shown. Graph A shows the life characteristics of an ultraviolet discharge lamp employing a thorium tungsten electrode, and graph B shows the life characteristics of an ultraviolet discharge lamp employing a cerium tungsten electrode. It turns out that the equivalent lifetime characteristic is shown. Such a cerium tungsten electrode can be similarly employ | adopted also for the ultraviolet discharge lamp of the following other embodiment.

(2nd embodiment)

The ultraviolet discharge lamp of 2nd Embodiment of this invention is demonstrated. The structure of the ultraviolet discharge lamp 52 of this embodiment is the same as that of 1st Embodiment shown in FIG. It is characterized by the amount of thallium iodide encapsulated in the discharge medium encapsulated in the airtight discharge container.

In the case of this embodiment, as a specification of a lamp | ramp, the tube outer diameter of 27.5 mm and thickness 1.5 mm in which the electrodes 521 and 522 made of tungsten (W) etc. were arrange | positioned inside the airtight container 520 made from quartz which has ultraviolet permeability. The light emission length L can be 1800 mm. In the airtight container 520, argon (Ar) gas, mercury, and thallium iodide (TII) are sealed as a discharge medium. The weight ratio Mr between mercury Hg and thallium iodide TII in this discharge medium is 10 ≦ Mr ≦ 200. By setting it as this ratio, when it is set to Mr <10, separated light emission will generate | occur | produce in the lamp axis direction. On the other hand, when Mr> 200, the luminescence intensity of thallium becomes small, so that only mercury luminescence is generated and disappears in the lamp utilizing thallium luminescence.

Moreover, also in this embodiment, when the light emitting tube internal diameter D is D <30mm, the potential hardness E (V / cm) at the time of stable lighting can be set to 8 <E <30, and it does not become an overload by this, and long lifetime And an ultraviolet lamp which effectively utilizes light emission of thallium.

(Third embodiment)

The ultraviolet discharge lamp of 3rd Embodiment of this invention is demonstrated. The structure of the ultraviolet discharge lamp 52 of this embodiment and the discharge medium to enclose are the same as that of 1st Embodiment shown in FIG. In the present embodiment, when the input power W (W / cm) and the inner surface area of the hermetic container are 2πr (cm 2), the tube wall load W / cm 2 is 0.5 <W / cm 2 <3.5, so that the lamp temperature is managed. It is characterized by the long life of the lamp.

For example, mercury 1.68 mg / cc with an outer diameter of 27.5 mm, a thickness of 1.5 mm, a luminous length L of 1000 mm, and an argon gas as a discharge medium, in which an electrode such as tungsten is disposed inside a hermetic container made of quartz. And an ultraviolet discharge lamp in which 0.1051 mg / cc of thallium iodide is encapsulated, the lamp is applied by applying power of a lamp voltage of 1100 V and a lamp current value of 10.2 A. Thus, by setting the tube wall load W / cm 2 to 1 <W / cm <2> 60, the lamp temperature can be managed, the temperature deterioration during lighting can be reduced, and the lamp with a long life can be obtained.

Moreover, also in this embodiment, when the light emitting tube internal diameter D is D <30mm, the potential hardness E (V / cm) at the time of stable lighting can be set to 8 <E <30, and it does not become an overload by this, and long lifetime And an ultraviolet lamp which effectively utilizes light emission of thallium.

In addition, when the inside diameter of an airtight container is 30 mm or less, and the input (W / cm) per unit length lights 60 W / cm or more, the encapsulation amount (mg / cc) of thallium iodide shall be 0.3 mg / cc or less. As a result, the emission intensity of the spectrum of 340 nm or less can be reduced, and the emission intensity of the spectrum of 352 nm, 365 nm, and 378 nm can be increased.

(4th embodiment)

4 and 5 show a lighting device of the ultraviolet discharge lamp of the fourth embodiment of the present invention. The ultraviolet discharge lamp lighting device of the present embodiment is characterized in that the sockets 523 and 524 of the lamp 52 itself and the sockets 525 and 526 for mounting on the circuit side are made of ceramics and have a common structure. .

In the present embodiment, the lamp 52 is fixed by mounting the external fixing sockets 525 and 526 on the circuit side and fitting with the steatite sockets 523 and 524 on the lamp 52 side. Both of these sockets 523 to 526 are made of ceramic. According to this embodiment, a metal component can be removed around an electricity supply part, an electrical safe mechanism can be ensured, and the design of low cost is attained by that.

In each of the above embodiments, cobalt halide (Co) or indium halide (In) may be employed instead of thallium halide.

Moreover, the ultraviolet discharge lamp of this invention can respond to the use of various exposure light sources, such as a printed board, drying, printing, and plate making baking.

<Example 1>

The ultraviolet discharge lamp of Example 1 of this invention seals the electrode which consists of tungsten in the both ends of the inside of the airtight container made from ultraviolet-permeable quartz of tube outer diameter (DELTA) 27.5mm, thickness 1.5mm, and light emission length 1000mm, and also the airtight container Mercury and thallium iodide are encapsulated inside as a light emitting metal together with argon gas. The loading amount was 1.6 mg / cc of mercury, thallium iodide 0.1 mg / cc, and argon 1.33 Pa. The electrical characteristics at that time were 1100V and 11.0A. The lamp had peaks of the respective metals in the ultraviolet region and gave uniform light emission in the axial direction. According to the spectroscopic analysis, in the case of the ultraviolet discharge lamp of Example 1, the illuminance of the wavelength due to thallium iodide, that is, the spectral components of 352 nm, 365 nm, and 378 nm is high, and the deviation of spectroscopy or illuminance in the axial direction, that is, separation It was confirmed that luminescence did not occur.

Thereby, by employing the filter which cut | disconnects the wavelength component of 320 nm or less strongly conventionally, the process which reliably suppressed the harmful ultraviolet wavelength range is attained.

<Example 2>

In the ultraviolet discharge lamp of Example 2, a tube outer diameter of 27.5 mm, a thickness of 1.5 mm, a light emission length L of 1800 mm, in which an electrode such as tungsten is disposed inside a hermetic container made of quartz, together with argon gas as a discharge medium, An ultraviolet discharge lamp encapsulated at a rate of 1.68 mg / cc of mercury and 0.032 mg / cc of thallium iodide (Mr = 52.5) was prepared.

Moreover, as the comparative example 1, the ultraviolet discharge lamp of the comparative example 1 which enclosed in the ratio of 1.09 mg / cc mercury and 0.218 mg / cc thallium iodide (Mr = 5) with the mercury container of the same specification was also prepared. Moreover, as the comparative example 2, the ultraviolet discharge lamp of the comparative example 2 which enclosed at the ratio of 1.09 mg / cc mercury and thallium iodide 0.001 mg / cc (Mr = 1090) with respect to the airtight container of the same specification was also prepared.

And the result of having discharged the ultraviolet discharge lamp of these Example 2, the comparative example 1, and the comparative example 2, and measured the spectral characteristic is shown to FIG. 6 (a)-(c). As shown in Fig. 6 (a), in the second embodiment of the present invention, spectra and illuminance deviation (separated light emission) do not occur in the lamp axial direction while being high illuminance, and light emission of thallium having a spectrum of 352 nm and 378 nm is achieved. The lamp characteristics that emit efficiently are shown. On the other hand, as shown in Fig. 6B, in Comparative Example 1 in which Mr < 10, a difference occurs in illuminance on the left and right of the lamp, and it is confirmed that separated light emission occurs. This is because by setting the ratio Mr <10 between mercury and thallium iodide, diffusion of the inclusions hardly occurs due to the atomic radius difference between mercury and thallium in the discharge plasma, and separate light emission occurs in the axial direction. In addition, as shown in Fig. 6C, in Comparative Example 2 in which Mr> 200, the spectrum of thallium becomes small, only mercury emission occurs, and the ultraviolet discharge lamp utilizing the characteristics of thallium iodide disappears.

<Example 3>

As an embodiment (Tl) of the present invention, an ultraviolet discharge lamp containing no iron element in a discharge medium, the outer diameter of a tube having a tube made of tungsten or the like in a hermetic container made of quartz, 27.5 mm, thickness 1.5 mm, and As the discharge medium, as shown in Table 1 of FIG. 7 encapsulated with mercury 1.68 mg / cc and thallium iodide at a rate of 0.024 mg / cc, a plurality of types of ultraviolet discharge lamps having different lamp lengths were prepared. Further, as a comparative example (Fe + Tl), an ultraviolet discharge lamp containing iron element in a discharge medium, a tube outer diameter of 27.5 mm, a thickness of 1.5 mm, and a discharge in which electrodes such as tungsten were disposed inside a hermetic container made of quartz As shown in Table 1, a plurality of types of ultraviolet discharge lamps having different lamp lengths are also encapsulated in a ratio of 1.10 mg / cc of mercury, 0.03 mg / cc of iron element, and 0.10 mg / cc of thallium iodide as a medium. Ready. In addition, when the presence or absence of the separate light emission was investigated, the light emission became unstable in the lamp length of 200 mm in the comparative example, but the light emission became unstable in the case of the 500 mm length, and the separate light emission was confirmed in the lamp of 750 mm or more. On the other hand, in the case of the Example of this invention, no separate light emission was recognized in any of lamp length 200mm-2300mm, and stable discharge light emission was obtained.

<Example 4>

It is 1.68 mg / cc of mercury, together with argon gas as a discharge medium, 27.5 mm in tube diameter, 1.5 mm in thickness, luminous length L is 1800 mm, and an electrode made of tungsten or the like is placed inside a hermetic container made of quartz. As shown in Table 2, plural kinds of ultraviolet discharge lamps in which the content of thallium iodide were different from each other were prepared, and the presence or absence of separate light emission and appropriateness of ultraviolet light intensity were investigated. As a result, even if it was content of the same mercury, it was confirmed that content of thallium iodide is 0.012 mg / cc or more and 0.032 mg / cc is suitable as conditions on which the desired ultraviolet illuminance is obtained without separating light emission.

<Example 5>

The ultraviolet discharge lamp of the Example of this invention seals the electrode which consists of tungsten in the both ends of the inside of the airtight container made from ultraviolet-permeable quartz of tube outer diameter (DELTA) 27.5mm, thickness 1.5mm, and light emission length 1000mm, Mercury and thallium iodide were enclosed with argon gas as a light emitting metal in the airtight container. The loading amount was 1.6 mg / cc of mercury, 0.032 mg / cc of thallium iodide, and 1.33 Pa of argon. The electrical characteristics at that time were 1100V and 11.0A. In addition, as a comparative example, an ultraviolet discharge lamp containing iron element in a discharge medium, the ultraviolet discharge lamp having the same specifications as the above-described embodiment, and sealed at a rate of 0.03 mg / cc iron element and thallium iodide 0.10 mg / cc. Was prepared. 9 and 10 show the results of measuring the spectral characteristics at the beginning of the life and the end of the life. In the comparative example shown in Fig. 10, the spectral components having wavelengths of 352 nm, 365 nm, and 378 nm due to thallium iodide are greatly reduced, and thus the lifespan is short, but in the case of the embodiment of the present invention shown in Fig. 9, There was almost no change in the spectral characteristics at the beginning and end of life, and it was confirmed that they had stable spectral characteristics.

BRIEF DESCRIPTION OF THE DRAWINGS The front view of the ultraviolet discharge lamp of 1st Embodiment of this invention.

2 is a graph of spectral characteristics of the above embodiment.

3 is a graph comparing the lifespan of a thorium tungsten electrode and a cerium tungsten electrode in the ultraviolet discharge lamp of the above embodiment.

4 is an exploded view of the socket portion in the embodiment;

Fig. 5 is an explanatory view of the mounting of the socket portion in the embodiment;

6 is a graph showing a change in light emission characteristics by thallium content of the embodiment.

7 is a comparison table of luminescence separation characteristics with a conventional example of the above embodiment.

8 is a table showing a change in luminescence properties by thallium content of the embodiment.

9 is a graph of light emission characteristics at the beginning and end of life of the embodiment.

Fig. 10 is a graph of light emission characteristics at the beginning of life and at the end of life of the conventional example.

<Description of the code>

52: ultraviolet discharge lamp 520: airtight container

521, 522: electrode 523, 524: socket

525, 526: external socket

Claims (6)

An ultraviolet discharge lamp characterized by not containing iron element as a discharge medium in a light emitting tube, and containing thallium halide together with mercury. The method of claim 1, The amount M of encapsulation of thallium halide is 0.01 mg / cc? M? 0.3 mg / cc when the inner diameter D? The method according to claim 1 or 2, When the light emission length L is 500 mm ≤ L ≤ 2500 mm at the inner diameter D ≤ 30 mm of the light emitting tube, the amount of Hg charged in mercury is 0.9 mg / cc ≤ Hg ≤ 5.0 mg / cc, and the amount M of thallium halide is filled. The ultraviolet discharge lamp, characterized in that 0.012 mg / cc ≤ M ≤ 0.1 mg / cc. The method of claim 1, As for the discharge medium of mercury and thallium halide contained in the said light emitting tube, when the inner diameter D of the said light emitting tube is D <30mm, the value of the potential hardness E (V / cm) at the time of stable lighting is 8 <E <30. Ultraviolet discharge lamp characterized by the amount of encapsulation taking value. The method according to claim 1, 2 or 4, The thallium halide is ultraviolet discharge lamp, characterized in that thallium iodide (TlI). The method of claim 5, The thallium iodide (TlI) is a ultraviolet discharge lamp, characterized in that the weight ratio Mr = Hg (mg / cc) / TlI (mg / cc) to mercury (Hg) is 10≤Mr≤200.

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