JP4984317B2 - Ultraviolet light source and ultraviolet irradiation device - Google Patents

Description

The present invention relates to a batch-type ultraviolet lamp and ultraviolet irradiation device used for sterilization and ultraviolet oxidative decomposition, ozone cleaning / modification, resin curing, and the like using ultraviolet rays.

Conventionally, an ultraviolet lamp can transfer electric energy to an object remotely because of its high energy, light emission of a specific wavelength, and straightness that is characteristic of light. In other words, it is well known that the photochemical reaction is applied to various fields in order to freely control the photochemical reaction.

The low-pressure mercury lamp has an excellent emission efficiency of ultraviolet rays of 185 nm and 254 nm, which are the main emission wavelengths, up to about 20 to 35% of electric power. In particular, the wavelength of 254 nm is a wavelength range characterized by sterilization exposure by acting on DNA and changing the thymine-thymine sequence of the gene to forcibly mutate and make it impossible to maintain survival. It is also called a germicidal line because it is very close to the 260 nm wavelength that acts. Since it also emits light in the vacuum ultraviolet region of 185 nm, it is used for ultraviolet oxidative decomposition, ozone cleaning and reforming. In recent years, the use of ozone cleaning has increased rapidly in the semiconductor, liquid crystal color filter, and panel manufacturing industries.

The main structure and operation of the low-pressure mercury lamp are as follows. In the arc tube, electrodes are sealed at both ends of the glass tube via lead wires, and mercury and a rare gas are sealed in the glass tube. And it discharges by applying a voltage between both electrodes, gives excitation energy to mercury, and makes it light-emit. In the emission spectrum, ultraviolet rays (mainly 254 nm and 185 nm) having a wavelength corresponding to the excitation energy are obtained.
High-pressure lamps are classified into mercury lamps and metal halide lamps with added mercury and other metals. The high-pressure lamps are characterized by high consumption by radiating ultraviolet light from mercury or other metals with a wavelength of 365 nm as lamp power. Can be output. Because of this feature, it can be used for high-speed curing and processing, and is used for surface coating for printing, plate making, furniture, etc. in combination with a special ultraviolet curable ink and resin.

In practice, quartz glass is used as the arc tube for high-pressure lamps because of its transmittance and cost, but since the arc temperature reaches 2000 ° C or higher, the lamp shape is a straight tube type or elliptical / spherical arc tube with a pair of electrodes sandwiched between them. It is common to consist of. In recent years, since the exposure pattern formation of semiconductors and liquid crystals is the most effective method at present, an ultra-high pressure mercury lamp is becoming larger year by year as a high output point light source.

In addition to low-pressure lamps and high-pressure lamps, there are light sources that use an inert gas discharge such as xenon. Xenon light emission has a wide wavelength range from vacuum ultraviolet to long wavelength and is rare gas light emission, so that the rise of light is extremely fast compared to mercury and metal halide lamps. On the other hand, although the luminous efficiency is low, it has been devised to increase energy and suppress heat generation as a flash lamp, and has been applied to DVD bonding, surface sterilization, chemical solution sterilization, etc., and development of applications has been progressing in recent years.

The rare gas discharge lamp described above is an electroded lamp in which an electrode is welded in an arc tube and electrons are supplied into the arc tube. However, a lamp utilizing excimer emission, that is, light emission by dimer excitation of xenon atoms has been developed. . Excimer lamps have been used in the flat panel manufacturing industry for liquid crystals and the like in recent years because they emit 172 nm vacuum ultraviolet light, which has higher energy than the emission wavelength by excitation of mercury and other metal atoms. Excimer lamps are currently used in the form of double tubes made of quartz glass or straight tube types of heating halogen lamps.
In recent years, ultraviolet LEDs have been developed.

The ultraviolet lamp is generally attached to a dedicated apparatus such as a batch type or a conveyor. In the flat panel manufacturing industry that requires mass production, in order to increase the manufacturing speed, the apparatus is generally a conveyor type, and in order to increase the amount of light, a plurality of lamps are often arranged side by side. In addition, with the increase in the size of irradiated objects, the UV lamps are also increasing in output and length.

On the other hand, unlike the conveyor type, the batch type of batch processing is often used for small-scale, multi-product production or for development and research experiments of companies and academic institutions. The batch irradiation apparatus adjusts the amount of ultraviolet light, that is, the energy, according to the ultraviolet output from the lamp and the irradiation time. FIG. 1 is a schematic view of a batch type ultraviolet irradiation apparatus. Reference numeral 1 denotes an ultraviolet lamp, and there is an irradiated surface 2 for processing the workpiece by irradiating ultraviolet rays from the ultraviolet lamp below. These are arranged inside the box 3 and constitute an ultraviolet irradiation device. In order to make it easy to put and take out the workpiece on the processing surface 2, it is a drawer, and the workpiece can be taken in and out at every experiment.

Conventionally, as shown in FIG. 11, the installation interval of the straight tube portion of the lamp bent a plurality of times is set at equal intervals irrespective of the size of the irradiated surface and the distance between the lamp and the processing surface. For example, the straight pipe portion is regarded as a cylinder as shown in FIG. 2 and these are designated as A, B, C, D, E, and F. The illuminance distribution of such a lamp is, for example, that there is B and D light emission on both sides just below the C light emitting part, so that high illuminance can be obtained due to that, but B just below the A light emitting part is B on one side. However, the illuminance is lower than that immediately below C. FIG. 3 is a view of the cylinder of FIG. 2 as viewed from the longitudinal cross section in the transverse direction, and shows a relative illuminance distribution (with a peak value of 100%) immediately below the cross section. As shown in FIG. 3, the illuminance immediately below the lamp is higher in the vicinity of C and D than in the vicinity of A and F, and therefore, irradiation unevenness of ultraviolet illuminance has occurred. In the ultraviolet irradiation apparatus, a uniform ultraviolet illuminance distribution surface of a certain level or more is used as an effective irradiation surface, but this effective irradiation surface is very small in the conventional ultraviolet lamp.

In Patent Document 1, although it is for a liquid crystal panel, in order to obtain uniform illuminance in the lamp axial direction, the liquid crystal panel is arranged so as to protrude in the axial direction. In Patent Document 2, although this is also for a liquid crystal panel, the film thickness of the phosphor film is changed by the arrangement of the lamps in order to improve the uniformity.

JP 07-175064 A JP 07-272507 A

In order to solve the above problems, the present invention provides an ultraviolet lamp and an ultraviolet irradiation device that obtain an irradiated surface with a high degree of uniformity of ultraviolet illuminance in a batch type ultraviolet irradiation device and further widen the effective irradiation surface. For the purpose.

The ultraviolet irradiation device according to the invention described in claim 1 is an ultraviolet light source body having a straight tube portion arranged in a planar shape inside a box , and an irradiated surface arranged in parallel with the light source body. In the batch type ultraviolet irradiation device comprising the above, the light source body has a straight tube portion arranged in parallel and symmetrically in parallel with six or more facing the surface to be irradiated to form one group, In the group of pipe parts, the distance between the straight pipe part at the outermost position in the direction perpendicular to the central axis of the straight pipe part and the adjacent straight pipe part is a straight line arranged at equal intervals inside the pipe part. It is characterized by being narrower than the interval between the tube portions .

The arrangement of the ultraviolet light source is not particularly limited, and is also arranged on the upper surface, the lower surface, or both surfaces with respect to the irradiated surface.

When the irradiated surface is arranged below the ultraviolet light source body, the ultraviolet rays emitted from the ultraviolet light source body are irradiated not only to the irradiated surface directly under the ultraviolet light source body but also toward the immediate lower periphery. Therefore, high illuminance can be obtained at the central portion of the irradiated surface by irradiation from the ultraviolet light source body around the ultraviolet light source body immediately above. However, when it is outside the irradiated surface, there is no ultraviolet light source body outside the directly above ultraviolet light source body, so that it is not possible to obtain high illuminance compared to the central portion of the irradiated surface. In particular, since the outermost surface of the irradiated surface is not irradiated with ultraviolet rays from the outer side, the illuminance is low.

Therefore, as described in claim 1, by arranging the ultraviolet light source bodies, the existence of the ultraviolet light source bodies does not change at the center of the irradiated surface, but the existence of the ultraviolet light source bodies relatively on the edge side of the irradiated surface. Therefore, ultraviolet irradiation is increased as a whole, and a uniform illuminance can be obtained as a surface to be irradiated.

According to the present invention, in the batch type ultraviolet irradiation device, the arrangement of the ultraviolet light source bodies installed on the upper surface, the lower surface, or both surfaces is symmetrical and centered with respect to the irradiated surface according to the shape of the light source body. By arranging the parts evenly spaced and the outermost side densely, compared to the central part, the light from the surroundings is not added and the illuminance on the outermost surface to be illuminated is low, and the degree of coverage is high. It is possible to obtain an irradiated surface. Thereby the light source are arranged all at equal intervals conventional, also can take wide effective irradiation surface than those using light sources arranged in parallel and all at equal intervals straight tube, increase the efficiency increase process lot be able to.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a batch type ultraviolet irradiation device, 1 is an ultraviolet light source body, 2 is a surface to be irradiated, and a work is placed on the surface to irradiate ultraviolet rays from the ultraviolet light source body. These are arranged inside the box 3 and constitute an ultraviolet irradiation device. The irradiated surface on which the work is placed is a drawer type, and is configured so that the work can be easily taken in and out.

FIG. 4 is a diagram showing the concept of an arrangement diagram of ultraviolet light source bodies for improving the uniformity of the irradiated surface of the batch type ultraviolet irradiation apparatus according to the present invention. In FIG. 4, FIG. 4 (a) is a conceptual diagram of an array density distribution of ideal ultraviolet light source bodies. 4B uses a plurality of straight tube type light source bodies in parallel (for example, a light source body in which straight tube portions are arranged in parallel as in FIG. 11), and the axis of the straight tube. It is a conceptual diagram of the arrangement | sequence dense distribution of the ultraviolet light source body which considered the uniformity improvement of the orthogonal | vertical direction. By arranging the ultraviolet light source bodies as shown in FIGS. 4A and 4B, the degree of uniformity of the irradiated surface becomes high, and as a result, a wide effective irradiated surface can be obtained.

If an ultraviolet LED is used, the ideal light source arrangement shown in FIG. 4A can be realized.
Hereinafter, a specific embodiment of the arrangement of light sources in consideration of the improvement in the degree of uniformity as shown in FIG. 4B will be described with reference to the drawings.

FIG. 5 shows an embodiment in which one of the ultraviolet lamps has a straight tube shape and each is arranged in parallel, and the intervals between the outer lamps are arranged narrower than the central portion. As the types of straight tube type ultraviolet lamps arranged in this way, it is possible to obtain an irradiation surface with a high degree of uniformity as long as the light source emits ultraviolet rays regardless of high pressure, low pressure, or the like.

FIG. 6 shows that one shape is composed of three U-shaped (or U-shaped) ultraviolet lamps, and the straight tube portions of the U-shaped lamps are arranged in parallel , and the U-shaped lamp existing in the center is arranged. The space | interval of the arc_tube | light_emitting_tube in the direction of the U-shaped lamp which exists outside a character-shaped lamp is narrowed. In this case, the target ultraviolet lamp can be mainly used for a low-pressure mercury discharge lamp in which the arc is close to the inner surface at the bent portion of the lamp and the temperature does not rise so as to melt the quartz tube. In this way, it is possible to obtain an irradiation surface having a high degree of uniformity as described above by the arrangement.

In FIG. 7, one long ultraviolet lamp is bent a plurality of times, and the obtained straight tube portions are arranged in parallel. And this ultraviolet lamp is comprised by 1 plane shape, and the space | interval of an outer straight tube | pipe part is comprised by the space | interval narrower than a center part. In this case, since the target ultraviolet lamp has a bent portion in the arc tube as described above, it can be mainly used for a lamp of low-pressure mercury discharge. In this way, it is possible to obtain an irradiation surface with a high degree of uniformity as described above.

In FIG. 8, one long ultraviolet lamp is bent a plurality of times, and the obtained straight tube portions are arranged in parallel. And the space | interval of this straight pipe part has narrowed one side. Further, lamps that are symmetrical with the shape of the ultraviolet lamp are arranged so that the straight tube portions are parallel. These two ultraviolet lamps are configured in one plane, and are configured such that the narrower the interval between the straight tube portions, the outer. In this case, since the target ultraviolet lamp has a bent portion in the arc tube as described above, it can be mainly used for a lamp of low-pressure mercury discharge. In this way, it is possible to obtain an irradiation surface with a high degree of uniformity as described above.

FIG. 9 shows that when the irradiated surface of the batch type ultraviolet irradiation device is circular, one ultraviolet lamp is formed in a ring shape, and ultraviolet lamps having concentric circles and different ring sizes are formed in the same plane. Forming. In the case of FIG. 9, these ultraviolet lamps are biased from the center to the end side with respect to the irradiated surface.

In this case, since the target ultraviolet lamp has a curved portion in the arc tube as described above, it can be mainly used for a lamp of low-pressure mercury discharge, and in this way, it is possible to obtain an irradiation surface with the same high degree of uniformity as described above.

Next, specific examples for proving the effects of the present invention are shown below.
The low-pressure mercury lamp is a hot cathode system, and the arc tube is made of synthetic quartz. As shown in FIG. 7, one arc tube is bent five times and six straight tube portions are provided. The arc tube has an outer diameter of 20 mm and a wall thickness of 1.2 mm. The arc tube was filled with 1.0 Torr of Ar as a buffer gas. An arrangement of straight tube portions of the arc tube was configured under the conditions shown in Table 1, and a comparative experiment of the illuminance on the irradiated surface was performed between the configuration of the present invention and the conventional configuration. The pitch of the arc tube straight tube portion is shown based on A, B, C, D, E, and F in FIG.

Table 2 shows the measurement system.

The measurement results in the above specifications are shown in FIG. (A) is a measurement result by the structure of this invention, (b) is a measurement result by the conventional structure. The longitudinal direction of the lamp straight tube was the A direction, and the transverse direction was the B direction. In FIG. 10, (a) and (b) each show an illuminance uniformity distribution diagram and a diagram showing only a distribution in which the illuminance uniformity of the surface to be irradiated is 80% or more. Compared to the conventional configuration, FIG. In the configuration, the distribution in which the illuminance uniformity of the irradiated surface is 80% or more is widened, that is, the effective irradiated surface can be widened. In particular, the difference is obvious at both ends in the transverse direction of the straight pipe portion. In the figure, 6 indicates an illuminance uniformity of 80% or more.

In the example, the experiment was performed using one low-pressure mercury lamp. However, even when there are a plurality of low-pressure mercury lamps, the arrangement of straight pipe portions is equally spaced on the inner side and the outermost side is more dense than this. By doing so, the same effect could be obtained.

Further, in the embodiment, a lamp including a straight tube portion is used so as to approximate the sparse / dense distribution of FIG. 4B. However, by using an ultraviolet LED as an ultraviolet light source body, as shown in FIG. A configuration close to a sparse / dense distribution can be obtained. As a result, it is possible to increase the illuminance on the outside of the irradiated surface where the light from the surroundings is not added compared to the central portion and the illuminance is low, and to obtain the irradiated surface with a high degree of uniformity. As a result, a conventional tube-type light source that is arranged at equal intervals from each other, and a wider effective irradiation surface than that using a light source having straight tube portions that are parallel to each other and arranged at equal intervals. It is possible to increase the processing lot and increase the efficiency.

It is a figure which shows the schematic of a batch type ultraviolet irradiation device. It is the schematic diagram which considered the arc tube straight tube | pipe part as the cylinder. It is a figure which shows the relative illumination intensity distribution of FIG. It is a figure which shows the concept of the light source arrangement | sequence diagram for improving the uniformity of the to-be-irradiated surface of the batch type ultraviolet irradiation device of this invention. It is a figure which shows embodiment of the light source arrangement | sequence at the time of using a straight tube | pipe type ultraviolet lamp for the batch type ultraviolet irradiation device of this invention, and arranging it in parallel. It is a figure which shows embodiment of the light source arrangement | sequence at the time of using a U-shaped ultraviolet lamp for the batch type ultraviolet irradiation device of this invention, and arranging it in parallel. It is a figure which shows embodiment of the light source arrangement | sequence at the time of bending one ultraviolet lamp in the batch type ultraviolet irradiation device of this invention several times, and providing several straight tube | pipe parts in parallel. It is a figure which shows embodiment of the light source arrangement | sequence at the time of using one lamp | ramp several times in the batch type ultraviolet irradiation device of this invention, and using two lamp | ramps which provided the straight tube | pipe part with two or more parallel. When the irradiation surface of the batch type ultraviolet irradiation apparatus of this invention is circular, it is a figure which shows embodiment in the case where multiple annular | circular shaped ultraviolet lamps are installed in a concentric shaft. It is a figure which shows the uniformity distribution in the to-be-irradiated surface of Example 1. FIG. (A) is a figure which shows the degree distribution according to this invention, (b) shows the figure which shows the degree distribution by the conventional structure. It is a figure which shows the lamp | ramp of the conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ultraviolet light source body 2 Irradiated surface 3 Box 4 Ultraviolet lamp straight pipe part 5 Ring-shaped ultraviolet lamp 6 Effective irradiation surface

Claims (3)

In a batch-type ultraviolet irradiation apparatus comprising an ultraviolet light source body having a straight tube portion arranged in a flat shape inside a box and an irradiated surface arranged in parallel with the light source body, the light source body is: 6 or more of the straight pipe portions are arranged in parallel and symmetrically so as to face the irradiated surface to constitute one group, and the straight pipe portion of the group is orthogonal to the central axis of the straight pipe portion. UV irradiation , characterized in that the distance between the straight pipe portion at the outermost position and the adjacent straight pipe portion is narrower than the interval between the straight pipe portions arranged at equal intervals inside apparatus. 2. The ultraviolet irradiation device according to claim 1 , wherein the ultraviolet light source body includes a plurality of long lamps. 2. The ultraviolet irradiation apparatus according to claim 1, wherein the ultraviolet light source body includes a lamp formed by bending one lamp a plurality of times.

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