JP7156959B2 - Light irradiation device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a light irradiation device for irradiating an object having a predetermined width with ultraviolet light, and more particularly to a device capable of irradiating light with good uniformity of illuminance and light quantity in the width direction of the object to be irradiated.

In order to align a liquid crystal alignment film included in a liquid crystal display element of a liquid crystal display panel, a technique called photo-alignment is known in which an alignment film or an alignment layer is aligned by irradiating polarized light. In addition, in order to bond the image display panel and the touch panel member together, an adhesive composition containing an ultraviolet curable resin as a main component is formed into a sheet and the adhesive composition is completely cured. A semi-cured state is obtained by irradiating light, the image display panel and the touch panel member are laminated while being aligned with each other through the semi-cured adhesive composition, and the adhesive composition is completely cured by irradiating ultraviolet light again. Therefore, the image display panel and the touch panel member are firmly adhered while avoiding the remaining air bubbles.

A light irradiation device for irradiating an object to be irradiated such as the alignment film with ultraviolet light (light) is known, for example, from Japanese Unexamined Patent Application Publication No. 2002-100000. In this apparatus, the X-axis direction is the width direction of the object to be irradiated, and the Y-axis direction is the direction orthogonal to the X-axis direction in the same plane. A rod-shaped light source is provided so as to face the transported object to be irradiated. Then, the line light emitted from the rod-like light source and linearly extending in the X-axis direction is applied to the object to be irradiated. At this time, regardless of the wavelength of the light emitted from the light source and the intensity (luminous intensity) of the light source, the illuminance of the line light is high in the center region of the object to be irradiated in the X-axis direction, and goes from the center region to both end regions in the X-axis direction. It is generally known that the illuminance decreases (that is, the illuminance unevenness occurs in the X-axis direction). When such a light irradiation device is used, in order to eliminate the influence on the quality of the alignment film due to the illuminance unevenness in the X-axis direction, the above-mentioned conventional example does not emit line light in the central region of the object to be irradiated. A neutral density filter is fixedly arranged between the object to be illuminated and the rod-like light source in order to reduce the illuminance and suppress illuminance unevenness.

By the way, the width in the X-axis direction that reduces the illuminance of the line light (in other words, the length in the X-axis direction of the dimming region) needs to be changed according to, for example, the type of object to be irradiated. In such a case, if a plurality of light-attenuating filters having different lengths of the light-attenuating regions in the X-axis direction are prepared and replaced each time according to the type of the object to be irradiated, not only is the replacement work troublesome. In addition, an adjustment work is required after the replacement work, resulting in a decrease in productivity. Therefore, development of a light irradiation device capable of automatically adjusting the length of the dimming region in the X-axis direction is desired.

JP 2017-15886 A

In view of the above points, an object of the present invention is to provide a light irradiation device capable of automatically adjusting the length of the dimming region in the X-axis direction.

In order to solve the above problems, the light irradiation device of the present invention for irradiating an object having a predetermined width with ultraviolet light has a width direction in the X-axis direction and a direction orthogonal to the X-axis direction in the same plane. is the Y-axis direction, and a light source that forms a line of light linearly extending in the X-axis direction; A neutral density filter that enables local light reduction, and a moving means that relatively moves the light density filter in the Y-axis direction with respect to the object to be irradiated, wherein the light density filter is inclined with respect to the Y-axis direction. The central area of the line light is dimmed at the starting point of the moving means, and the dimming area of the line light is shifted to the X axis as the starting point is moved in one direction along the Y axis. It is characterized in that it is configured to expand in the direction. It should be noted that the present invention includes one in which the neutral density filter is relatively moved in the X-axis direction as well as in the Y-axis direction (that is, rotated in the θ direction around the intersection of the X-axis and the Y-axis).

According to the present invention, when the light-reducing filter is moved relative to the object to be irradiated in the Y-axis direction by the moving means, the width of the light-reducing region of the line light in the X-axis direction changes. It is possible to adjust the variation in the illuminance (or amount of light) of the light that irradiates the body. Therefore, unlike the conventional example, it is not necessary to replace the light-attenuating filter each time according to the type of the object to be irradiated, and adjustment work after the replacement work is not required, so that productivity can be improved.

In the present invention, each side of the neutral density filter is preferably inclined at an inclination angle of 30 degrees or less with respect to the Y-axis direction. If the angle of inclination of each side is greater than 30 degrees, the amount of change in the dimming region with respect to the amount of movement of the neutral density filter in the Y-axis direction becomes large, making it impossible to accurately control the illuminance of the dimming region and, by extension, the line light. occurs.

In the present invention, it is preferable that the light-reducing filter has a mesh-like light-reducing portion that has a trapezoidal outline and reflects or absorbs the light from the light source.

In the present invention, it is preferable to further include measuring means for measuring the illuminance of the light irradiated onto the object to be irradiated, and control means for controlling the moving means based on the measured value of the measuring means. According to this, it is possible to accurately control the illuminance of the light with which the object to be irradiated is irradiated.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram which shows the light irradiation apparatus of embodiment of this invention. FIG. 2 is a perspective view showing the neutral density filter shown in FIG. 1; (a) is an explanatory view of the light-reducing filter at the starting position, and (b) is an explanatory view showing the light-reducing filter after movement.

Hereinafter, a light irradiation apparatus according to an embodiment of the present invention will be described with reference to the drawings, taking as an example a case where a strip-shaped base material having a predetermined width is used as an object to be irradiated Wb and the object to be irradiated is irradiated with light. do. In the following description, the width direction is defined as the X-axis direction, and the direction orthogonal to the X-axis direction within the same plane is defined as the Y-axis direction.

Referring to FIG. 1, LM is the light irradiation device of this embodiment. The light irradiation device LM includes transport rollers 1a and 1b as transport means for transporting the irradiated object Wb in the Y-axis direction. As the object to be irradiated Wb, a single-layer or multi-layer plastic film, or an adhesive film or adhesive sheet in which an adhesive layer is formed by coating an adhesive on a plastic film, or the like can be used. Suitable examples of plastic films include thermoplastic resins such as polypropylene resin, polyethylene resin, acrylonitrile-butadiene-styrene resin, polyethylene terephthalate, polystyrene, polyimide, polycarbonate, and polyurethane. Although the width of the object to be irradiated Wb is not particularly limited, it is preferably 1400 mm or less, more preferably in the range of 300 mm to 1000 mm.

A light source 2 is arranged below the irradiated body Wb so as to face the portion of the irradiated body Wb between the conveying rollers 1a and 1b. The light source 2 is provided with a rod-shaped lamp 21 elongated in the X-axis direction and a housing box 22 with an open upper surface in which the rod-shaped lamp 21 is housed, so that line light extending in the X-axis direction can be formed. A UV (ultraviolet) lamp can be used as the rod-shaped lamp 21 . A distance d1 from the light source 2 to the object to be irradiated Wb (hereinafter also referred to as “irradiation distance”) is appropriately set according to the illuminance and amount of light irradiated to the object to be irradiated Wb, and is set in the range of 200 to 1200 mm, for example. be. The length of the light source 2 in the X-axis direction (hereinafter referred to as “light source width”) is set according to the width of the object to be irradiated Wb, but is usually in the range of 1 to 1.5 times the width of the object to be irradiated Wb. is set to For example, when the width of the object to be irradiated Wb is 1400 mm, the width of the light source is set in the range of 1400 to 2100 mm, preferably in the range of 1600 to 2000 mm, more preferably in the range of 1800 to 1900 mm. The length of the light source 2 in the Y-axis direction is preferably 200 mm or less, more preferably in the range of 100 mm to 150 mm.

A light-attenuating filter 3 is arranged between the light source 2 and the object to be irradiated Wb to enable local attenuation of the line light from the light source 2 . The light-reducing filter 3 is connected to a driving shaft 4a of a motor 4 as moving means, so that it can move relative to the irradiated body Wb in the Y-axis direction. The distance d2 from the light source 2 to the neutral density filter 3 is preferably set, for example, within the range of 100 mm to 300 mm, more preferably within the range of 150 mm to 250 mm.

Referring also to FIG. 2, the neutral density filter 3 is, for example, one in which metal wires 3b are assembled in a mesh shape so as to define an opening 3a that allows the passage of light from the light source 2 (see FIG. 2). 3), and punching metal can be used. The light attenuation rate of the light-attenuating filter 3 (ratio of the area of the light-shielding portion (wire material 3b) to the area of the entire light-attenuating filter 3) is preferably set in the range of 20% to 80%, more preferably 25% to 75%. It is more preferable to set it to a range. If it is lower than 20%, a sufficient light attenuation rate for suppressing uneven illuminance cannot be obtained. there is a risk of Any material can be used for the light-reducing filter 3 as long as it can block light and has resistance to light irradiation. For example, metal such as stainless steel is preferable. The thickness of the neutral density filter 3 (the wire diameter of the wire 3b) is, for example, preferably 2 mm or less, more preferably in the range of 0.1 mm to 1 mm. If it is larger than 2 mm, only the light incident perpendicularly to the light-reducing filter 3 can be transmitted, and as a result, sufficient light cannot be applied to the object to be irradiated Wb. may be deformed. The neutral density filter 3 has a contour with two sides 31a and 31b inclined with respect to the Y-axis direction, and specifically has a trapezoidal or triangular contour. The inclination angle θ of each side 31a, 31b with respect to the Y-axis direction is preferably set to 30 degrees or less. If the tilt angle θ is greater than 30 degrees, the amount of change in the dimming region with respect to the amount of movement of the dimming filter 3 in the Y-axis direction becomes large, and there is a problem that the illuminance of the dimming region and, by extension, the line light cannot be controlled with high accuracy. . When the neutral density filter 3 has a trapezoidal outline, the length of the upper base is preferably 0.3 to 0.5 times the width of the light source, more preferably 0.3 to 0.4 times the width of the light source. The length of the lower base is preferably 0.7 to 0.9 times the width of the light source, more preferably 0.8 to 0.9 times the width of the light source. can. Both ends of the neutral density filter 3 in the Y-axis direction are held by a rectangular frame 32, and both ends of the frame 32 in the X-axis direction are guided by a pair of guide members 33 extending in the Y-axis direction. A drive shaft 4a of the motor 4 is connected to one outer surface of the frame 32 in the Y-axis direction. By adopting such a configuration, by driving the motor 4, the frame 32 and thus the light-reducing filter 3 can be moved in the Y-axis direction relative to the object to be irradiated Wb. For example, at the starting position of the motor 4, the central region of the line light is attenuated by the dimmer filter 3, as shown in FIG. 3(a). Then, when the motor 4 is operated from this starting point to relatively move the light-reducing filter 3 in one direction of the Y-axis to the position shown in FIG. The light area spreads in the X-axis direction. By using a motor 4 having an encoder (not shown), the value of the encoder and the position of the light-reducing filter 3 are associated in advance and stored in the control means Cu, which will be described later, so that the light-reducing filter 3 can be moved with high precision.

A plurality of (five in this embodiment) illuminance meters 5 serving as measuring means are arranged in parallel in the X-axis direction above the object Wb to be irradiated. It is designed to measure the illuminance of the light that is applied. The measured value of each illuminance meter 5 is input to the control means Cu. The control means Cu is a known device including a microcomputer, a sequencer, etc. The control means Cu controls the operation of the conveying rollers 1a and 1b, the operation of the light source 2, the operation of the motor 4, and the like. The illuminance variation is obtained from the measured value input from the total 5, and the motor 4 is feedback-controlled based on the illuminance variation. A method of irradiating the object Wb with light using the light irradiation device LM will be described below.

First, the width of the dimming region of the line light in the X-axis direction (hereinafter also referred to as “dimming region width”) Rx is adjusted according to the material of the object Wb so that the variation in illuminance falls within the target range. It is determined. Then, the target position of the neutral density filter 3 in the Y-axis direction that realizes the light density region width Rx is obtained. For example, if the type of the object to be irradiated Wb is associated with the target position of the dimming region width Rx and the neutral density filter 3 in the Y-axis direction and stored in the control means Cu, The dimming region width Rx and the target position can be acquired. The motor 4 is driven to relatively move the neutral density filter 3 in the Y-axis direction.

When the light-attenuating filter 3 is moved to the target position, a motor (not shown) rotates the conveying rollers 1a and 1b, thereby conveying the irradiated body Wb in the Y-axis direction at a predetermined speed. While the object Wb to be irradiated is being transported in this way, the UV light is irradiated from the light source 2 onto the part of the object Wb to be irradiated.

Here, since the object Wb to be irradiated has light transmission properties, the illuminance of the UV light transmitted through the object Wb to be irradiated is measured by each illuminometer 5 . If the difference between the illuminance measured by the illuminance meter 5 and the determined illuminance is different from a preset reference value, the motor 4 is driven based on the difference to correct the position of the neutral density filter 3. You may do so.

According to the above, the width of the dimming region of the line light in the X-axis direction (dimming region width) Rx can be changed by moving the dimming filter 3 relative to the irradiated body Wb in the Y-axis direction. As a result, it is possible to change the illuminance (or the amount of light) of the light with which the object to be irradiated Wb is irradiated. Therefore, unlike the conventional example, it is not necessary to replace the light-reducing filter 3 each time according to the type of the object to be irradiated Wb, or to perform adjustment after the replacement, thereby improving productivity.

Next, an example that embodies the embodiment of the present invention and a reference example for the example will be described. In Example 1, a polyethylene terephthalate film (manufactured by Toray Industries, Inc., trade name “PET25 T60”) having a width of 1400 mm was used as the object to be irradiated Wb, and the light source 2 was arranged to face the object to be irradiated Wb. A distance d1 from the light source 2 to the irradiated object Wb was set to 1000 mm. As the rod-shaped lamp 21 of the light source 2, an ultraviolet curing lamp (trade name “H296-L41X” manufactured by Eye Graphics Co., Ltd.) having a width of 1850 mm was used. A light-attenuating filter 3 was placed between the object Wb to be processed and the light source 2, and the distance d2 from the light source 2 to the light-attenuating filter 3 was set to 160 mm. As the light-attenuating filter 3, Expandmental (manufactured by Okutani Wire Net Co., Ltd.) was used by cutting it into a trapezoidal outline. The light-attenuating filter 3 has a light-attenuating portion (metal) that reflects light, and its light-attenuating rate is 50%. The motor 4 was driven to move the light-reducing filter 3 in the Y-axis direction to a position where the width of the line light attenuating region (the width in the X-axis direction of the light-reducing filter 3 covering the light source 2) Rx was 1200 mm. In this state, the line light from the light source 2 was irradiated to the irradiated object Wb. Five illuminance meters 5 arranged above the object to be irradiated Wb measure the illuminance of line light transmitted through the object to be irradiated Wb (corresponding to the line light irradiated to the object to be irradiated Wb) at five points in the X-axis direction ( −700 mm, −350 mm, 0 mm (center), +350 mm, +700 mm), and the illuminance variation (±%) obtained from these measured values by the following formula (1) was ±2.9%. In the following formula (1), I _max indicates the maximum value among the five measured illuminances, and I _min indicates the minimum value among the five measured illuminances.
Illuminance variation [±%]=(I _max −I _min )/(I _max +I _min )×100 (1)
The illuminance variation obtained from the above equation (1) is an index representing the variation of I _max and I _min from the measured median value of illuminance (value between I _max and I _min ).

Here, the illuminance variation was evaluated not only in Example 1 but also in Examples 2 to 29 and Reference Examples 1 to 5, which will be described later. Regarding the evaluation, when the obtained illuminance variation was less than ±3%, it was evaluated as “◯”; when it was ±3% or more and less than ±5%, it was evaluated as “Δ”; Table 1 shows the evaluation result of such illuminance variation and the various conditions of the light irradiation device described above.

Next, in Example 2, after moving the light-reducing filter 3 in the Y-axis direction to a position where the line light attenuation region width Rx is 900 mm, the line light is irradiated under the same conditions as in Example 1, and the illuminance is The dispersion was found to be ±3.2%.

In Reference Examples 1 and 2 for Examples 1 and 2, after moving the light-reducing filter 3 in the Y-axis direction to positions where the line-light attenuation region width Rx is 500 mm and 1500 mm, the same conditions as in Example 1 were applied. When the illuminance variation was obtained by irradiating the line light at , all of them were deteriorated to ±5.6%.

In Example 3, line light was emitted under the same conditions as in Example 1, except that the distance d1 from the light source 2 to the object to be illuminated Wb was 500 mm, and the dimming region width Rx was 1500 mm. It was found to be ±2.4%. In Example 4, the illuminance variation was found to be ±3.9% by irradiating line light under the same conditions as in Example 3, except that the dimming region width Rx was 1400 mm.

In Reference Example 3 for Examples 3 and 4, line light was irradiated under the same conditions as in Example 3 except that the dimming region width Rx was 1600 mm, and the illuminance variation was determined to be ±5.8. % worsened.

In Example 5, line light was emitted under the same conditions as in Example 1, except that the distance d1 from the light source 2 to the irradiated object Wb was 200 mm, and the dimming region width Rx was 1400 mm, thereby reducing illuminance variations. It was found to be ±2.5%. In Example 6, the illuminance variation was found to be ±2.5% by irradiating line light under the same conditions as in Example 5, except that the dimming region width Rx was set to 1500 mm.

In Reference Example 4 for Examples 5 and 6, line light was irradiated under the same conditions as in Example 5 except that the dimming region width Rx was 1300 mm, and the illuminance variation was determined to be ±25.2. % worsened.

In Example 7, line light was applied under the same conditions as in Example 1, except that the distance d2 from the light source 2 to the neutral density filter 3 was 150 mm, and the light attenuation region width Rx was 1100 mm. It was found to be ±2.9%. In Example 8, the line light was irradiated under the same conditions as in Example 7, except that the distance d1 from the light source 2 to the object Wb to be irradiated was 500 mm, and the dimming region width Rx was 1500 mm. The dispersion was found to be ±2.3%. In Example 9, line light was irradiated under the same conditions as in Example 8, except that the distance d1 from the light source 2 to the object Wb to be illuminated was set to 200 mm. was 5%.

In Example 10, the illuminance variation was determined by irradiating line light under the same conditions as in Example 1, except that the distance d2 from the light source 2 to the neutral density filter 3 was 200 mm. Met. In Example 11, line light was applied under the same conditions as in Example 10, except that the distance d1 from the light source 2 to the object Wb to be irradiated was 500 mm, and the dimming region width Rx was 1450 mm. The dispersion was found to be ±2.6%. In Example 12, line light was applied under the same conditions as in Example 8, except that the distance d1 from the light source 2 to the object Wb to be irradiated was 200 mm, and the dimming region width Rx was 1600 mm. The dispersion was found to be ±2.5%.

In Example 13, line light was irradiated under the same conditions as in Example 1 except that the light source width was 2000 mm, and the illuminance variation was determined to be ±2.2%. In Example 14, line light was applied under the same conditions as in Example 13, except that the distance d1 from the light source 2 to the irradiated object Wb was 500 mm, and the dimming region width Rx was 1600 mm. The dispersion was found to be ±2.1%. In Example 15, line light was irradiated under the same conditions as in Example 14, except that the distance d1 from the light source 2 to the object Wb to be irradiated was 200 mm, and the illuminance variation was found to be ±2. was 1%.

In Example 16, line light was irradiated under the same conditions as in Example 1 except that the light source width was 1600 mm and the dimming region width Rx was 900 mm. Met. In Example 17, line light was applied under the same conditions as in Example 16, except that the distance d1 from the light source 2 to the object to be irradiated Wb was 500 mm, and the dimming region width Rx was 1200 mm. The dispersion was found to be ±2.1%. Further, in Example 18, the line light was irradiated under the same conditions as in Example 17 except that the distance d1 from the light source 2 to the irradiated object Wb was 200 mm and the dimming region width Rx was 1300 mm. The dispersion was found to be ±2.2%.

In Example 19, line light was irradiated under the same conditions as in Example 1, except that the distance d1 from the light source 2 to the irradiated object Wb was 500 mm, and the light attenuation rate of the light-attenuating filter 3 was 30%. The illuminance variation was found to be ±1.1%. In Example 20, line light was applied under the same conditions as in Example 19, except that the distance d1 from the light source 2 to the object to be irradiated Wb was 200 mm, and the dimming region width Rx was 1400 mm. The dispersion was found to be ±1.8%.

In Reference Example 5 with respect to Examples 19 and 20, line light was emitted under the same conditions as in Example 19 except that the distance d1 from the light source 2 to the irradiated body Wb was 1000 mm and the dimming region width Rx was 800 mm. When the illuminance variation was determined by irradiating with , it deteriorated to ±7.1%.

In Example 21, the illuminance variation was obtained by irradiating line light under the same conditions as in Example 1, except that the light attenuation rate of the light attenuation filter 3 was 40% and the light attenuation region width Rx was 950 mm. By the way, it was ±4.8%. In Example 22, the line light was irradiated under the same conditions as in Example 21, except that the distance d1 from the light source 2 to the irradiated object Wb was 500 mm, and the dimming region width Rx was 1400 mm. The dispersion was found to be ±1.3%. In Example 23, line light was irradiated under the same conditions as in Example 22, except that the distance d1 from the light source 2 to the object Wb to be illuminated was 200 mm, and the illuminance variation was found to be ±1. was 8%.

In Example 24, the illuminance variation was determined by irradiating line light under the same conditions as in Example 1 except that the light attenuation rate of the light attenuation filter 3 was 60% and the light attenuation region width Rx was 1300 mm. By the way, it was ±1.3%. In Example 25, the line light was irradiated under the same conditions as in Example 24, except that the distance d1 from the light source 2 to the object to be irradiated Wb was 500 mm, and the dimming region width Rx was 1500 mm. The dispersion was found to be ±4.2%. In Example 26, line light was applied under the same conditions as in Example 25, except that the distance d1 from the light source 2 to the object Wb to be illuminated was set to 200 mm. was 5%.

In Example 27, the illuminance variation was determined by irradiating line light under the same conditions as in Example 1, except that the light attenuation rate of the light attenuation filter 3 was set to 70% and the light attenuation region width Rx was set to 1600 mm. By the way, it was ±2.0%. In Example 28, line light was applied under the same conditions as in Example 27, except that the distance d1 from the light source 2 to the object Wb to be illuminated was set to 500 mm. was 5%. In Example 29, line light was irradiated under the same conditions as in Example 28, except that the distance d1 from the light source 2 to the object Wb to be illuminated was 200 mm, and the illuminance variation was found to be ±2. was 5%.

According to the above examples and reference examples, it was found that the light attenuation region width Rx can be adjusted by moving the light attenuation filter 3 in the Y-axis direction. Furthermore, it was found that the illuminance variation (illuminance unevenness) in the X-axis direction can be reduced as shown in the examples.

The present invention is not limited to the above embodiments and examples, and various modifications are possible without departing from the scope of the present invention. For example, in the above embodiment, the case in which the light-reducing filter 3 is relatively moved in the Y-axis direction has been described as an example. may In this case, the width of the line light in the X-axis direction is changed by rotating the light-reducing filter 3 in the θ direction around the intersection of the X-axis and the Y-axis.

Further, in the above-described embodiment, a light-transmitting object Wb is used as the object to be irradiated Wb, and the illuminance of the line light transmitted through the object Wb is measured by the illuminance meter 5. If the body Wb does not have light transmittance, the illuminance of the reflected light reflected by the body Wb to be illuminated may be measured.

Further, in the above-described embodiment, a case where the object to be irradiated Wb is conveyed by the conveying rollers 1a and 1b has been described as an example, but a known device can be used as means for conveying the object to be irradiated Wb.

Further, in the above-described embodiment, the case where the metal wire rod 3b that constitutes the neutral density filter 3 reflects light has been described as an example. It is also possible to use a device configured as follows.

LM... light irradiation device, Wb... object to be irradiated, 2... light source, 3... light-reducing filter, 3b... wire (light-reducing portion), 31a, 31b... two sides inclined with respect to the Y-axis direction, θ... Y-axis Inclination angle with respect to direction, 4 motor (moving means), 5 illuminometer (measuring means), Cu control means.

Claims (3)

In a light irradiation device that irradiates an object having a predetermined width with ultraviolet light,
Between a light source that forms a line of light linearly extending in the X-axis direction, with the width direction as the X-axis direction and the direction perpendicular to the X-axis direction in the same plane as the Y-axis direction, and the light source and the object to be irradiated. a light-reducing filter arranged in the illuminating body to enable local light reduction of the line light irradiated toward the object to be irradiated; and moving the light-reducing filter relative to the object to be irradiated in the Y-axis direction. a means of transportation,
The light-reducing filter has a contour with two sides inclined with respect to the Y-axis direction, and attenuates a central region of the line light at the starting point of the moving means, and relatively moves from the starting point in one Y-axis direction. is configured so that the dimming region of the line light spreads in the X-axis direction along with
A light irradiation device , wherein each side of the neutral density filter is inclined at an inclination angle of 30 degrees or less with respect to the Y-axis direction . 2. The light irradiation device according to claim 1 , wherein said light-attenuating filter has a mesh-like light-attenuating portion which has a trapezoidal outline and reflects or absorbs light from a light source. 3. The apparatus according to claim 1, further comprising measuring means for measuring the illuminance of the light irradiated onto the object to be irradiated, and control means for controlling the moving means based on the measured value of the measuring means. light irradiation device.

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