JPH034435A - Metal halide lamp - Google Patents

Abstract

PURPOSE:To obtain much luminous distribution in a near ultraviolet region and in a blue region by sealing a specific amount of neodymium iodide and dysprosium iodide in addition to mercury, auxiliary gas for starting, further cesium iodide and mercury iodide respectively into a discharge container an not providing an external float for the sake of airtightness. CONSTITUTION:Neodymium iodide(NdI3) and dysprosium iodide(DyI3) in addition to mercury, auxiliary gas for starting having the weight ratio in the range of 0.5<=NdI3<=5 while having the total weight of 0.5 to 0.05mg/cc are sealed into a discharge container 1 provided with a pair of electrodes 2, 3 on both ends while having lamp power above 100W/cm per interelectrode arc length. Further, cesium iodide 0.25 to 2 times to the total weight of NdI3 and DyI3 and mercury iodide of under 0.5mg/cc are sealed in while not providing an external float for the sake of airtightness. Thereby, high luminous strength can be obtained in a near ultraviolet region and a blue region as well as an excellent characteristic to a diazo-photosensitive agent and UV hardening resin.

Description

Detailed Description of the Invention [Field of Industrial Application] This invention relates to a metal halide lamp used as a light source for sensitizing and curing photosensitizers that are sensitive in the near-ultraviolet region and blue region, and resins that harden in similar wavelength regions. .

[Conventional technology]

Conventionally, ultraviolet rays have been mainly used as a light source for sensitizing photosensitizers such as diazo photosensitive liquids that are sensitive in the near ultraviolet region or blue region around 450 nm, or as a light source for curing ultraviolet curable resins (UV curable resins). A high pressure mercury lamp is used.

Further, the curing agent and photosensitizer used in the UV curing resin have spectral sensitivity in a fairly wide wavelength range, as shown in FIG.

In Figure 3, the curve ■ is a diazo photosensitizer, and the curve ■
is the spectral sensitivity characteristic of the curing agent (dichromic acid type) used for UV curing resin. Therefore, the spectrum of mercury is 365n
It can be seen that sufficient effects can be achieved not only by a light source having an emission wavelength in the wavelength region (2) but also by a light source having an emission wavelength in another region, that is, from 350 to 450 nm.

Gallium iodide (GaI) emits light in such a wide wavelength range.
Lamps containing srGalg and Galυ have also been proposed, and are thought to be expected to have some degree of effectiveness.

[Problem to be solved by the invention]

By the way, ultra-high-pressure mercury lamps used as conventional light sources for photosensing and curing have a high vapor pressure of 50 atm or more, which increases the mercury vapor pressure in order to promote strong light emission at and around the dominant wavelength of 365 rv. It is common to do so. However, when the vapor pressure is set to such a high level, there is a problem that there is a high risk of the arc tube bursting.

Further, in lamps containing gallium iodide, the vapor pressure of gallium iodide is high, and therefore, when constructing a small lamp, arc stability is poor and miniaturization is difficult. Furthermore, when welding the electrodes onto the encapsulating foil, tantalum or platinum is usually used as a flux material, but in lamps containing gallium, the gallium reacts with the flux material, causing There were problems in that the seal part of the arc tube would crack and even burst, resulting in a short lifespan.

The present invention was made to solve the above-mentioned problems of conventional light sources for photosensitization and curing. tJ
The purpose of the present invention is to provide a metal halide lamp that has excellent properties even for V-curing resin.

[Means and operations for solving the problem] In order to solve the above problems, the present invention comprises a pair of electrodes at both ends, and the lamp power per arc length between the electrodes is 100 W/e1.
In addition to mercury and starting auxiliary gas, neodymium iodide (Ndl3) and dysprosium iodide (yl3) are placed in a discharge vessel having a size of 0.5≦Nd1s/Dy1s in a weight ratio of 0.5≦Nd1s/Dy1s.
≦5 and total weight 0.5-0.05M/e
0.25 to 2 times the total weight of Ha I s and Dy I s and 0.25 to 2 times the amount of cesium iodide and 0.5 u/ee or less of mercury iodide are sealed, and an outer sphere is provided for airtightness. It is characterized by the fact that there is no

By adding neodymium iodide and dysprosium iodide and increasing the power per arc length, it has high emission intensity in the near-ultraviolet and blue regions, making it suitable for diazo photosensitizers and UV curing resins. A light source with excellent characteristics can be obtained. In addition, there is no occurrence of cracks or blackening at the electrode welded portion of the seal portion, making it possible to extend the service life.

〔Example〕

Embodiments will be described below. FIG. 1 is a perspective view showing an embodiment of a metal halide lamp according to the present invention. In the figure, reference numeral 1 denotes a quartz discharge vessel whose central section is approximately elliptical.Both ends of the vessel 1 are provided with a cathode electrode 2 and an anode electrode 3, and the electrodes 2 and 3 are for power supply. and are welded to molybdenum foil 4 connected to molybdenum lead wire 5 for airtight sealing. In addition, 6 is
This is the tip-off part of the discharge vessel 1.

The internal volume of the discharge vessel 1 is approximately 0°2 cc,
The maximum outer diameter of the central part of the ellipse is 8 m, and the inner diameter is 6.4 y.
m, and the arc length is set to be 5 m.

The discharge vessel 1 contains Nd at a weight ratio of 2:1.
0.2 Kg of I 5-Cs
mg, 0°1 mg of HgIz, and 411 g of mercury as a buffer gas.

And about 300 torr of Ar is sealed as a starting auxiliary gas.

With the arc tube formed in this way, the lamp power is 10OW.
, a lamp voltage of 85 cm, and a lamp current of 1.2 A, which constitutes a metal halide lamp for DC power supply. The light emission distribution of this lamp is shown by the curve δ in FIG. Note that the radiation intensity is a measured value at 50C11.

In addition, for comparison, the luminescence distribution of an ultra-high pressure mercury lamp with the same power is shown as a curve, and the luminescence distribution of a lamp doped with gallium iodide is shown as a curve C. By comparing these luminescence distribution curves, the present invention is Such metal halide lamps have higher emission intensity in the near-ultraviolet and blue regions than other light sources, and are said to have great effects on diazo photosensitizers and UV-cured resins. found.

Next, as a second example, a discharge vessel of the same shape with a maximum outer diameter of 12 mm and an inner diameter of 10 m5 was used, the arc length was 8 mm, and Nd I s Cs! (weight ratio 2:1) is 0゜311g, D)'I3C! IN (weight ratio 2:l) is 0.2 K, Hg I* is 0.15
A lamp with a lamp power of 200 W was prepared by enclosing 1 g of mercury, 11 g of mercury, and 200 torr of Ar. When the spectral characteristics of the lamp constructed in this manner were measured, it was found that the lamp maintained the same spectral characteristics as in the first embodiment and had excellent characteristics.

However, in a metal halide lamp configured in this way, if the weight ratio of Nd1s/Dy1s is less than 0.5, the boundary area increases in the luminescence distribution, making it unsuitable for diazo photosensitizers and UV curing resins. I understand. It has also been found that if the weight ratio of Nd I s/Dy I s exceeds 5, it is unsuitable because the blue light emission of Dy is suppressed.

In addition, the total weight of Nd I x and Dy1s is 0.5 to Q,
The reason for specifying Q51Ig/cc is that there is little shadow of colored additives that melt and adhere to the wall of the arc tube, and it is suitable for obtaining a predetermined luminescence. The reason why the amount of cesium iodide added is 0.25 to 2 times the total weight of Nd I 2 and ay I is because cesium iodide mainly emits infrared light, but h I , or Nd I at the ratio within the above range, Dyl, or Nd I
This is because the vapor pressure of s can be increased and desired light emission can be obtained. Also, the amount of mercury iodide added was 0.5
The reason for setting it below M/cc is as follows. That is, mercury iodide is a substance that hardly contributes to luminescence, but is used to suppress the rise in lamp voltage during its life. However, if added in a large amount, since it is a substance that inhibits starting, the starting performance deteriorates and blackening may occur, so it is necessary to use it in a limited manner as described above.

Furthermore, when the arc tubes according to each of the above embodiments were housed inside an outer bulb and turned on while the outer bulb was evacuated, the vapor pressure inside the arc tube increased and a luminescence distribution as shown in curve a in FIG. 2 was obtained. It was found that the desired effects could not be obtained with respect to diazo photosensitizers and UV curing resins. Furthermore, when the lamps of the above embodiments are lit at a low power of 100 W/CI or less per arc length, a light emission distribution similar to curve a in FIG. 2 is obtained, but due to the low power, the light emission energy is low; The effect on photosensitizers and UV curing resins is reduced.

Therefore, in order to improve the luminous efficiency in the near-ultraviolet and blue regions, it was found that it was necessary to set the lamp power to 100 W/el1 or more per arc length, and to use the arc tube as it was as a lamp without using an outer bulb. did.

Further, when life tests were conducted on the arc tubes according to each of the above examples, it was confirmed that there was no cracking or blackening at the electrode welding part of the seal portion, and that a long life of 2000 hours was obtained.

〔Effect of the invention〕

As explained above based on the examples, according to the present invention, it has high emission intensity in the near ultraviolet region and blue region, and can be used as a light source with excellent characteristics for diazo photosensitizers and UV curing resins. You can get a metal halide lamp that can.

In addition, a metal halide lamp can be obtained which prevents the occurrence of cracks and blackening at the electrode welding part of the seal part and has a longer service life.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the metal halide lamp according to the present invention, FIG. 2 is a diagram showing the light emission characteristics of the metal halide lamp shown in FIG. 1 and a conventional lamp, and FIG.
The figure shows the spectral sensitivity characteristics of a diazo photosensitizer and a curing agent for UV curing resin. In the figure, 1 is a discharge vessel, 2 is a cathode electrode, 3 is an anode electrode, 4 is a molybdenum foil, 5 is a molybdenum lead wire, and 6 is a sealing part.

Claims (1)

[Claims] 1.In addition to mercury and starting auxiliary gas, neodymium iodide (N
dI_3) and dysprosium iodide (DyI_3),
The weight ratio is in the range of 0.5≦NdI_3/DyI_3≦5 and the total weight is 0.5 to 0.05 mg/cc,
Furthermore, 0.25 to the total weight of NdI_3 and DyI_3
A metal halide lamp characterized by containing twice as much cesium iodide and 0.5 mg/cc or less of mercury iodide, and having no outer bulb for airtightness.