CN102081262A - Ultraviolet irradiation device - Google Patents

Abstract

The invention provides an ultraviolet irradiation device, which comprises an ultraviolet lamp and a reflection plate equipped with a diffusion reflection surface. The ultraviolet lamp made of UV-permeable material is formed into a tubular shape. The reflection plate is arranged opposite to the ultraviolet lamp. The cross section of the reflection plate is in a parabolic shape on the plane orthogonal to the axis of the ultraviolet lamp. The parabolic shape of the reflection plate meets at least one of the following two conditions: The first condition is that the minimum curvature radius r is greater than 82 mm and less than 88 mm. The second condition is that the opening width w is greater than 227 mm and less than 300 mm.

Description

UV irradiation device

technical field

The present invention relates to an ultraviolet irradiation device for irradiating an ultraviolet ray to a panel (substrate to be processed) under manufacture, for example, for the manufacture of a liquid crystal panel.

Background technique

In the manufacture of liquid crystal panels, a substrate to be processed in which liquid crystals and photoreactive polymers are sealed is cooled and irradiated with ultraviolet rays from an ultraviolet irradiation device. The ultraviolet irradiation device is provided with a filter that suppresses the transmission of ultraviolet rays with a wavelength of 340nm or less, and through the ultraviolet irradiation through the filter, the polymer body inside the substrate to be processed is reacted to form an opposing portion (for example, refer to JP2008-116672 ( KOKAI).

In the above techniques, in order to manufacture high-quality liquid crystal panels, it is very important to form an alignment film that aligns liquid crystals in a predetermined direction with good controllability. Generally, the "rubbing method" of wiping the film with a cloth is used, but when using the rubbing method, there are problems such as falling dust, adhering dirt, or damaging semiconductor elements on the substrate to be processed due to static electricity.

Therefore, as a technique instead of the rubbing method, a technique of forming a photoreactive substance on a substrate and irradiating ultraviolet rays to chemically react the photoreactive substance so as to have an alignment function is employed. In this case, there is a problem that if the intensity of ultraviolet rays irradiated to the liquid crystal panel (substrate to be processed) varies, the alignment film cannot be formed uniformly with good controllability.

Therefore, examples of ultraviolet irradiation devices that reduce unevenness in the intensity of ultraviolet rays include those disclosed in JPH8-225992 (KOKAI), WO2006/094220, and JPH6-260295 (KOKAI). In order to improve the unevenness of intensity, these devices use reflective plates that reflect ultraviolet rays toward the substrate to be processed, and this document also describes that it is preferable to perform a certain process in advance so that the reflective surface has light diffusing properties. However, even with the surface processing techniques described in these documents, there is still a limit to the reduction of intensity unevenness, and especially for the production of liquid crystal panels, an ultraviolet irradiation device with less intensity unevenness is required.

Contents of the invention

An object of the present invention is to provide an ultraviolet irradiation device capable of irradiating a wider area with ultraviolet rays of uniform intensity.

In order to solve the above-mentioned problems, an ultraviolet irradiation device according to an embodiment of the present invention is characterized in that it includes: an ultraviolet lamp formed in a tubular shape from a material having ultraviolet permeability; The plate is arranged opposite to the ultraviolet lamp, and is formed to have a parabolic cross-section on a plane perpendicular to the axis of the ultraviolet lamp, and the parabolic shape of the reflecting plate satisfies the following first condition and second condition At least one of the two conditions of the composition, the first condition is that the minimum curvature radius R is not less than 82 mm and not more than 88 mm, and the second condition is that the opening width W is not less than 227 mm and not more than 300 mm.

According to the present invention, it is possible to provide an ultraviolet irradiation device capable of irradiating a wider area with ultraviolet rays of uniform intensity.

Description of drawings

FIG. 1 is a longitudinal sectional view showing a basic structure of an ultraviolet irradiation device according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional view in the direction of the arrow at the position A-Aa shown in Fig. 1 .

Fig. 3 is a configuration diagram showing the ultraviolet lamp shown in Fig. 1 in some detail.

Fig. 4 is a graph comparing intensity spectral distributions of iron-based metal halide lamps and thallium-based metal halide lamps.

FIG. 5 is a perspective view illustrating an example of the shape of the reflection surface of the reflection plate shown in FIG. 1 .

FIG. 6 is an explanatory view enlargedly showing the surface of the region indicated by arrow A of the reflection plate shown in FIG. 5 .

7A and 7B are explanatory diagrams showing comparatively the reflection form of ultraviolet rays of the reflection plate of the comparative example and the reflection plate shown in FIG. 5 .

FIG. 8 is a graph comparing the intensity distribution of the ultraviolet irradiation surface irradiated by the ultraviolet irradiation device shown in FIG. 1 with a comparative example.

9 is an arrangement diagram (sectional view) further explaining the positional relationship between the ultraviolet lamp and the reflection plate in the ultraviolet irradiation device according to the embodiment.

10 is a table showing the results of measuring the uniformity of the intensity of the ultraviolet irradiation surface when the minimum curvature radius R and the opening width W of the reflection plate of the ultraviolet irradiation device according to the embodiment were changed.

FIG. 11 is a graph extracted from the table shown in FIG. 10 and drawn when the opening width W of the reflector is 230 mm.

FIG. 12 is a graph extracted from the table shown in FIG. 10 and drawn when the minimum radius of curvature R of the reflector is 85 mm.

Fig. 13 is a longitudinal sectional view showing a basic structure of an ultraviolet irradiation device according to another embodiment of the present invention.

Fig. 14 is a longitudinal sectional view in the direction of the arrow at the position B-Ba shown in Fig. 13 .

Fig. 15 is a partial enlarged view of the longitudinal sectional view shown in Fig. 14 .

Fig. 16 is a longitudinal sectional view schematically showing the structure of an ultraviolet irradiation device according to another embodiment of the present invention.

Symbol Description

100 UV lamps

200, 300 cooling unit

11 discharge space

12 luminous tubes

13a, 13b Electrodes

14a, 14b inner wire

15a, 15b metal foil

16a, 16b socket

17a, 17b wire

18 cooling blocks

181 cooling fins

19, 94 reflector

21 lampshades

23 window

24 Short wavelength side light cut filter

25, 93 Long wavelength side light cut filter

26 cover

27 suction port

28 Vents

29 exhaust pipe

30a, 30b power supply line

61 reflective surface

31 inner tube

32 outer tube

33a, 33b Connecting pipe

34 Coolant.

Detailed ways

(Description of Example)

Embodiments of the present invention are described with reference to the accompanying drawings, but these drawings are provided for illustration purposes only and they are not intended to limit the invention in any way.

Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the accompanying drawings.

1 to 3 are diagrams for explaining an ultraviolet irradiation device according to an embodiment of the present invention, FIG. 1 is a longitudinal sectional view showing its basic structure, and FIG. 2 is an arrow at the position A-Aa shown in FIG. 1 A longitudinal cross-sectional view in the direction, Fig. 3 is a structural diagram showing the ultraviolet lamp shown in Fig. 1 in a little detail.

As shown in FIGS. 1 and 2 , this ultraviolet irradiation device has, for example, four ultraviolet lamps 100 and a cooling unit 200 .

As shown in FIG. 3 , the ultraviolet lamp 100 is provided with an arc tube 12 having an airtight discharge space 11 made of quartz glass having ultraviolet transmittance and formed in a tubular shape. A pair of electrodes 13a, 13b made of, for example, tungsten are disposed inside both axial ends of the arc tube 12 . The arc tube 12 is, for example, a single-layer tube having an outer diameter φ of 27.5 mm, a wall thickness m of 1.5 mm, and a light emitting length L of about 1800 mm.

Electrodes 13a, 13b are welded to one ends of metal foils 15a, 15b via inner wires 14a, 14b, respectively. The other ends of the metal foils 15a and 15b are welded to one end of an unshown outer lead. Parts of the metal foils 15a, 15b are used to heat and seal the arc tube 12 between the inner wires 14a, 14b and the outer wires.

In addition, the metal foils 15a and 15b may be made of any material as long as the coefficient of thermal expansion is close to that of the quartz glass forming the arc tube 12, and a molybdenum thin plate satisfying this condition is used here. The other end of the outer wire that one end is respectively connected with metal foil 15a, 15b is electrically connected with power supply wire 17a, 17b that is insulated and sealed in, for example, socket 16a, 16b made of ceramics, and wire 17a, 17b is connected to a power supply not shown in the figure. circuit connection.

In the discharge space 11, in addition to a sufficient amount of rare gas for maintaining the arc discharge, mercury, halogen, and iron, tin, indium, bismuth, thallium, and manganese, which are metals for emitting ultraviolet rays, are sealed. At least one selected from the group formed. Thereby, ultraviolet rays with a wavelength of 300 to 400 nm can be emitted. In addition, technically, the wavelength of 380nm is often used as the boundary between ultraviolet light and visible light, but since this application represents a continuous wavelength region, it is conveniently expressed as "ultraviolet light with a wavelength of 300-400nm".

Fig. 4 is a graph comparing intensity spectral distributions of an iron-based metal halide lamp in which iron is enclosed in the luminescent metal and a thallium-based metal halide lamp in which thallium is enclosed. As can be seen from FIG. 4 , these lamps can obtain ultraviolet rays having a wavelength of 300 to 400 nm.

Referring again to FIGS. 1 and 2 , reference numeral 18 is a cooling block made of, for example, aluminum. On one side of the cooling block 18 , a reflection plate 19 facing the upper semicircumferential surface of the ultraviolet lamp 100 is in contact with, and on the other side, a plurality of cooling fins 181 are integrally formed. The reflecting plate 19 is made of, for example, SUS (stainless steel) material, aluminum material, or the like.

In addition, a member (not shown) with high thermal conductivity is arranged between the back surface of the reflection plate 19 and the cooling block 18, so that the heat of the reflection plate 19 can be more easily transferred to the cooling block 18, thereby achieving higher efficiency. cooling.

As shown in FIG. 5 , in this embodiment, the reflector 19 has a reflective surface shape (parabolic cross section) whose cross section is, for example, Y=(1/170)·X ² . The reflection plate 19 is arranged to face the ultraviolet lamp 100 at a constant interval, and has a parabolic cross section in a plane perpendicular to the axis of the ultraviolet lamp 100 . Also, the reflective surface is a diffusive reflective surface. An example of the surface state is described, for example, the state shown in FIG. 6 . FIG. 6 is an explanatory view enlargedly showing the surface of the region indicated by arrow A of the reflection plate shown in FIG. 5 . That is, the combination of fine reflection surfaces 61 along the curved surface of the surface becomes a surface in a state in which incident light is diffused. Thereby, as shown in FIG. 7B , the ultraviolet rays incident on the reflection plate 19 are diffusely reflected. 7A and 7B are explanatory diagrams showing comparatively the reflection form of ultraviolet rays of the reflection plate of the comparative example and the reflection plate shown in FIG. 5 . The reflection plate 19 having the reflection surface 61 having such a diffusion function can be formed by, for example, press processing of a mold. In addition, it can also be obtained by embossing the surface.

In the case of using an aluminum material as the reflection plate 19, the following methods can be employed as another method for imparting ultraviolet diffusibility to the surface. As one of them, an aluminum material having a mirror-finished surface is used as a base material, and hammering or whitewashing is performed on the surface to form irregular irregularities. Alternatively, instead of forming irregular irregularities, a surface structure in a predetermined pattern such as a honeycomb shape may be formed.

Also, as another example of the reflecting plate 19, a dichroic mirror that has diffuse reflectivity especially for ultraviolet rays by forming a multi-layer metal oxide vapor-deposited layer on the glass surface can also be used. Also, as another example of the reflecting plate 19, a material having ultraviolet reflectivity such as barium sulfate is vapor-deposited or adhered to a glass surface or a metal surface with a coarse particle size, for example.

Referring to FIGS. 1 and 2 again, the cooling fins 181 play a role in easily dissipating heat generated by the ultraviolet lamp 100 so that the temperature of the ultraviolet lamp 100 does not rise above a predetermined level. A lampshade 21 capable of accommodating the ultraviolet lamp 100 and the reflector 19 is formed on the lower side of the cooling block 18 .

As shown in Fig. 1 and Fig. 2, a window 23 through which the ultraviolet rays emitted from the ultraviolet lamp 100 pass is formed on the wall of the lampshade 21 opposite to the ultraviolet lamp 100, and a window for cutting off, for example, a wavelength of 320 nm or less is provided on the window 23. Short-wavelength side light cut filter 24 for ultraviolet rays, and long-wavelength side light cut filter 25 for cutting visible light above 400 nm and infrared rays.

When the ultraviolet lamp 100 is discharged and turned on, ultraviolet rays with a wavelength of 320 to 400 nm pass through the short-wavelength side light-cut filter 24 and the long-wavelength side light-cut filter 25 to the liquid crystal panel (substrate to be processed) as the object to be irradiated. irradiated. Thereby, a chemical reaction of the photoreactive substance by ultraviolet rays occurs, and an alignment film is formed.

On the upper side of the cooling block 18, a cover 26 covering the cooling block 18 is arranged along the lamp axis direction of the ultraviolet lamp 100 as a part of the cooling structure. A suction port 27 is formed at one end of the cover 26 in the longitudinal direction, and a ventilation port 28 is formed at the other end. Then, a cylindrical exhaust tube 29 is attached so as to communicate with the vent port 28 .

One of the high-frequency output ends of the high-frequency lighting device 500 is connected to an electrode 13a of the ultraviolet lamp 100 via a power supply line 30a, a lead wire 17a, etc. etc. are connected to the other electrode 13b of the ultraviolet lamp 100. When power is applied to the high-frequency lighting device 500 , a high-frequency voltage is applied between the electrodes 13 a and 13 b, whereby ultraviolet rays can be generated in the discharge space 11 .

FIG. 8 shows the intensity distribution of the ultraviolet irradiation surface irradiated by the ultraviolet irradiation device shown in FIG. 1 in comparison with a comparative example. Here, the horizontal axis "measuring point" in FIG. 8 represents a position on a straight line Z (see FIG. 5 ) perpendicular to the longitudinal direction of the reflector 19 taken on a plane facing the reflector 19 .

As shown in FIG. 8 , compared with the comparative example, this embodiment has an average intensity in the entire area of the measurement point due to the effect of the light diffusion function of the surface of the reflection plate 19 .

Therefore, the ultraviolet irradiation device of this embodiment can irradiate uniform ultraviolet rays to a liquid crystal panel (substrate to be processed) as an object to be irradiated, and thus can contribute to improvement of the yield of liquid crystal panel manufacture.

Next, FIG. 9 is an arrangement diagram (cross-sectional view) for further explaining the positional relationship between the ultraviolet lamp 100 and the reflection plate 19 in the ultraviolet irradiation device according to the embodiment. Next, an ideal arrangement relationship between the ultraviolet lamp 100 and the reflection plate 19 will be described.

As shown in FIG. 9 , the reflecting plate 19 symmetrically expands toward two wings with the central axis of the parabola as the center, and the space between the two wings is defined as the opening width W. In addition, each section of the reflector 19 in the direction perpendicular to the paper surface is the same, so the center of the parabola is defined as the central axis of the parabola extending in the direction perpendicular to the paper surface. The height H is defined as the maximum dimension in the up-down direction of the parabola projected on the plane perpendicular to the direction of the opening width W. A parabola exhibits a minimum radius of curvature R at the center of the parabola. Also, the focal point is generally defined on a parabola. The focal point is defined as a point where, when parallel light including light rays in the normal direction to the center of the parabola is incident on the reflector 19 , reflected light of the parallel light is focused on one point. Since the cross-sections of the reflection plate 19 in the direction perpendicular to the paper surface are the same, the focal point can be defined as a focal axis extending in the direction perpendicular to the paper surface. As shown in the drawing, the axis of the arc tube of the ultraviolet lamp 100 is located at least in a plane including the central axis and the focal axis of the parabola, and is parallel to these two axes.

10 is a table showing the results of measuring the uniformity of the intensity of the ultraviolet irradiation surface when the minimum curvature radius R and the opening width W of the reflection plate of the ultraviolet irradiation device according to the embodiment were changed. The so-called uniformity is a value obtained by quantifying the degree of intensity unevenness in the ultraviolet irradiated surface with a predetermined calculation formula. The lower the value [%], the better the uniformity, and the higher the value [%], the worse the uniformity . Here, using the maximum intensity and the minimum intensity in the ultraviolet irradiation plane, the uniformity was obtained by the calculation formula (maximum intensity-minimum intensity)/(maximum intensity+minimum intensity). In addition, here, as the reflector 19, the reflector whose surface was embossed was used.

In this measurement, in addition to defining the minimum radius of curvature R and opening width W, the ultraviolet lamp 100 was placed at a position where its central axis was 55 mm from the central axis of the parabola. Also, the diameter of the ultraviolet lamp 100 is 70 mm. In addition, when the opening width W and the minimum curvature radius R of the parabola are limited, the height H of the parabola is uniquely determined.

As shown in Figure 10, the uniformity of strength is optimal when the minimum curvature radius R is 85 mm and the opening width W is 230 mm. Therefore, under the conditions at this time, the distance from the central axis of the parabola to the focal axis is 42.5 mm, and the height H of the parabola is 80 mm. Since the distance from the central axis of the parabola to the focal axis is 42.5 mm, the central axis of the ultraviolet lamp 100 is disposed at the following position, that is, viewed from the central axis of the parabola of the reflector 19 on the side of the focal axis of the parabola away from the reflector 19 , and is located inside the height of the parabolic shape of the reflecting plate 19 . When this condition is deviated from, for example, when the arc tube axis is located on the side of the central axis of the parabola relative to the focal axis, thermal deformation of the reflector 19 tends to occur due to the short distance between the reflector 19 and the lamp 100 . The uniformity may deteriorate due to this effect. In addition, when it deviates to the opposite side, that is, when the axis of the luminous tube is located outside the height of the parabolic shape, the reflected light is easily blocked by the lamp 100, and the light utilization efficiency decreases, so the uniformity will still deteriorate.

FIG. 11 is a graph extracted from the table shown in FIG. 10 and drawn when the opening width W of the reflector is 230 mm. FIG. 12 is a graph extracted from the table shown in FIG. 10 and drawn when the minimum radius of curvature R of the reflector is 85 mm. In Fig. 12, it was measured until W = 300 mm, but it cannot be larger than this value because of other limitations on the space of the device.

It can be seen from Fig. 10 to Fig. 12 that in order to keep the uniformity of the intensity close to the minimum, it can be satisfied that the minimum curvature radius R of the parabola is not less than 82 mm and not more than 88 mm, that is, the first condition and the opening width W of the parabola is not less than 227 mm. And less than 300mm is at least one of the two conditions composed of the second condition. Especially good if both conditions are met.

In addition, in the measurement whose results are shown in FIG. 10, the reflecting plate 19 was used as the reflective plate whose surface was embossed. board results. As a result, the uniformity of strength is generally poor by about 4%. Therefore, by making the reflective surface of the reflector 19 light-diffusing and limiting the value of the minimum radius of curvature R or the opening width W of the above-mentioned parabola of the reflector 19, a reflector with particularly good uniformity can be obtained. .

Next, FIGS. 13 to 15 are diagrams for explaining another embodiment of the ultraviolet irradiation device of the present invention, FIG. 13 is a longitudinal sectional view showing its basic structure, and FIG. 14 is a B- A longitudinal sectional view in the direction of the arrow at the Ba position, and FIG. 15 is a partially enlarged view of the longitudinal sectional view shown in FIG. 14 . In these drawings, the same symbols are assigned to the same components as those shown in the drawings already described.

In this embodiment, in order to maintain the ultraviolet lamp 100 at a predetermined temperature (for example, 850° C.), the cooling method is a water-cooled type. This embodiment is the same as the embodiment described with reference to FIG. 1 and FIG. 2 , and will be described below by taking a configuration including, for example, four ultraviolet lamps 100 as an example. These four ultraviolet lamps 100 are accompanied by their respective cooling units 300 .

A predetermined distance is maintained between the ultraviolet lamp 100 and the cooling unit 300 by spacers 91a, 91b attached to the sockets 16a, 16b of the ultraviolet lamp 100 .

The cooling unit 300 has a double-layer pipe structure including a cylindrical inner pipe 31 made of a material having ultraviolet light permeability such as quartz glass and an outer pipe 32 provided outside the inner pipe 31 . The ultraviolet lamp 100 is enclosed in the inner tube 31 .

The inner tube 31 of the cooling unit 300 has an inner diameter d1 of, for example, 32 mm, an outer diameter d2 of, for example, 36 mm, an inner diameter d3 of the outer tube 32 of, for example, 66 mm, and an outer diameter d4 of, for example, 70 mm.

In the cooling unit 300, a cooling fluid 34 such as water is circulated from the outside through connecting pipes 33a, 33b provided at both ends of the outer periphery thereof. That is, the cooling liquid 34 having a low temperature is supplied from the connecting pipe 33 a side, and the cooling liquid 34 moves while cooling the ultraviolet lamp 100 , and the heated cooling liquid 34 is collected from the connecting pipe 33 . The heat-recovered coolant 34 is cooled by a cooling device (not shown), and supplied again to the connecting pipe 33a side.

On the outer surface of the outer tube 32, long-wavelength side light cut filters 93 for cutting visible light and infrared rays are respectively formed. Depending on the situation, the short-wavelength side light cut filter 92 for cutting unnecessary ultraviolet rays may be formed by overlapping.

On the upper side of the cooling unit 300 in the drawing, a reflection plate 94 having a reflection surface having ultraviolet diffusing properties is disposed. The reflection plate 94 is, for example, the same structure as that described with reference to FIG. 5 , FIG. 6 , and FIG. 7( b ).

When the ultraviolet lamp 100 is discharged and turned on, ultraviolet rays with a wavelength of 320 to 400 nm pass through the long-wavelength side light cut filter 93 to irradiate the liquid crystal panel (substrate to be processed) which is the object to be irradiated. Thereby, a chemical reaction of the photoreactive substance by ultraviolet rays occurs, and an alignment film is formed.

Ultraviolet rays with a wavelength of 320 to 400 nm are not only directly irradiated from the ultraviolet lamp 100 to the object to be irradiated, but also diffusely reflected by the reflector 94 to reach the object to be irradiated. As described above, the intensity of the superimposed ultraviolet rays on the irradiated object has a well-uniform distribution as shown in FIG. 8 , for example. Therefore, by applying it to a liquid crystal panel manufacturing process, an alignment film can be formed uniformly with good controllability.

The ultraviolet ray irradiation device of this embodiment can irradiate uniform ultraviolet rays to a liquid crystal panel (substrate to be processed) as an object to be irradiated, and thus can contribute to improvement of the yield of liquid crystal panel manufacture. In this embodiment, since the cooling unit 300 using the cooling liquid 34 is used, the cooling capacity is high, so the ultraviolet lamp 100 can be easily maintained at a predetermined temperature (for example, 850° C.), which has great advantages in terms of, for example, the life of the device. Big plus.

Next, FIG. 16 is a longitudinal sectional view schematically showing the structure of an ultraviolet irradiation device according to another embodiment of the present invention. In this figure, the same code|symbol is attached|subjected to the member which is the same as or equivalent to the member shown in the drawing already demonstrated. As long as there is no item that should be added, its description is omitted.

As shown in FIG. 16 , in this ultraviolet irradiation device, eight ultraviolet lamps 400 are arranged in parallel in the lateral direction of the drawing, and each ultraviolet lamp 400 is accompanied by a reflector 410 . A filter 420 is provided at a position opposite to the ultraviolet lamp 400 on the opposite side of the reflection plate 410 . Then, the opposite side of the ultraviolet lamp 400 across the filter 420 is an ultraviolet irradiation surface on which an object to be irradiated is placed. The horizontal width of the irradiated surface is, for example, 1890 mm in the drawing, and thus can be used in the manufacture of large liquid crystal panels.

Even such an ultraviolet irradiation device requiring a particularly large irradiation surface can irradiate ultraviolet rays of uniform intensity by applying the same technique as that described in the above-mentioned embodiment.

The ultraviolet lamps in each embodiment described above are not limited to the long-arc metal halide lamps described above, and may be ultraviolet lamps such as flash lamps, dielectric barrier discharge lamps, and electrodeless lamps.

The present invention is not limited to the specific forms illustrated and described herein, and includes all modifications within the scope of the claims.

Claims (5)

1. An ultraviolet irradiation device, characterized in that, comprising: an ultraviolet lamp formed in a tubular shape from a material having ultraviolet transparency; and a reflection plate having a diffuse reflection surface, the reflection plate is arranged opposite to the ultraviolet lamp, and is formed so that the cross section presented on a plane perpendicular to the axis of the ultraviolet lamp is a parabolic shape, The parabolic shape of the reflecting plate satisfies at least one of two conditions consisting of the following first condition and a second condition. The condition is that the opening width W is not less than 227 mm and not more than 300 mm. 2. The ultraviolet irradiating device according to claim 1, wherein the ultraviolet lamp is configured such that the axis of the ultraviolet lamp is located in such a position that it is separated from the central axis of the parabola of the reflecting plate. The reflecting plate is positioned on one side of the focal axis of the parabolic shape and inside the height of the parabolic shape of the reflecting plate. 3. The ultraviolet irradiation device according to claim 1 or 2, further comprising a cooling unit provided on the opposite side of the reflection plate to the side opposite to the ultraviolet lamp. 4. The ultraviolet irradiation device according to claim 1 or 2, further comprising a water-cooled cooling unit of a double-tube structure provided to cover the ultraviolet lamp. 5. The ultraviolet irradiation device as claimed in claim 1 or 2, characterized in that, it also has a short-wavelength side light cut-off filter and a long-wavelength side light cut-off filter, both of which are arranged on the side from the ultraviolet lamp and The reflector irradiates the object to be irradiated with ultraviolet rays in the space before reaching the object to be irradiated, the short-wavelength side light cut-off filter cuts off short-wavelength light with a shorter wavelength than the ultraviolet rays, and the long-wavelength side light cuts off The filter cuts light having a long wavelength longer than the ultraviolet rays.

Images