JP6512041B2 - Light alignment device - Google Patents

Description

  The present invention relates to a light directing device comprising a wire grid polarizer.

Conventionally, a lamp is accommodated in an elliptical mirror, and a polarizer is provided between the elliptical mirror and the light alignment film of the liquid crystal panel as a light alignment object, and the polarized light polarized by the polarizer is irradiated to the light alignment film of the liquid crystal panel An optical alignment device is known (see, for example, Patent Document 1). In this optical alignment device, a wire grid polarizer is used as a polarizer, and the wire grid is formed of titanium oxide with less deterioration of ultraviolet light, whereby light with a wavelength of 300 nm or less is favorably polarized.
Moreover, in the optical alignment device, a device that emits light having a wavelength of around 254 nm is mainly used.

JP, 2009-265290, A

There are several types of materials for the photoalignment film, and it has been found that the characteristics of the liquid crystal panel are excellent when using a photoalignment film oriented with light having a main wavelength of 365 nm.
Since the wavelength range around 365 nm is also ultraviolet light, it is necessary to use a wire grid polarizer that transmits ultraviolet light efficiently and does not deteriorate with ultraviolet light, but the above-mentioned conventional configuration has resistance to ultraviolet light, but 300 nm or more Good polarization characteristics can not be obtained with light.
The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a light alignment device provided with a wire grid polarizer capable of obtaining good polarization characteristics even when the polarization target is light in the ultraviolet region of 300 nm or more. I assume.

  In order to achieve the above-mentioned object, in the optical alignment device of the present invention, a metal halide lamp or a high pressure mercury lamp is accommodated in an elliptical mirror, and a filter transmitting at least a wavelength of 320 to 450 nm is transmitted to the exit of the elliptical mirror. A polarizer that arranges and polarizes light transmitted through the filter, wherein a Si wire grid is formed on a base material, and the polarization is formed by covering the Si wire grid with a mixed material of silicon oxide and aluminum oxide by trench filling It is characterized by having a child.

  In the above-described configuration, the filter may be a filter that transmits light with a wavelength of 340 to 400 nm.

  According to the present invention, it is possible to provide a light alignment device provided with a wire grid polarizer capable of obtaining good polarization characteristics even when the polarization target is light in the ultraviolet region of 300 nm or more.

It is a front view which shows typically the optical alignment apparatus which concerns on 1st Embodiment of this invention. It is a front view showing a light alignment device. It is a figure which expands and shows the light irradiator of FIG. It is a figure which shows the structure of a polarizer unit, (A) is a top view, (B) is a side cross sectional view. It is a schematic diagram which shows a wire grid polarizer. It is a figure which shows the durability which concerns on the polarized light transmittance | permeability of a wire grid polarizer. It is a figure which shows the durability which concerns on the extinction ratio of a wire grid polarizer. It is a figure which shows the relative spectral distribution figure of a high pressure mercury lamp. It is a figure which shows the relative spectral distribution figure of a metal halide lamp.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front view schematically showing a light alignment device according to the present embodiment, and FIG. 2 is a view showing the light alignment device. FIG. 3 is an enlarged view of the light irradiator of FIG. FIG. 4 is a view showing the configuration of the polarizer unit, FIG. 4 (A) is a plan view, and FIG. 4 (B) is a side sectional view.
As shown in FIG. 1, the light alignment device 1 is a light irradiation device which performs light alignment by irradiating polarized light onto a light alignment film of a plate-like or strip-like light alignment object (work) W (FIG. 2) .

The light alignment device 1 includes a stage transport rack 81, an irradiator installation rack 82, a work stage (stage) 83 on which the light alignment target W is placed, and a light irradiator 2 that irradiates polarized light immediately below. Have.
The irradiator installation rack 82 is a portal extending horizontally in the width direction of the stage conveyance rack 81 (a direction perpendicular to the linear movement direction X of the linear movement mechanism described later) at an upper position away from the stage conveyance rack 81 by a predetermined distance. The two columns are fixed to the stage carrier 81. The irradiator installation stand 82 incorporates the light irradiator 2 and the light irradiator 2 irradiates polarized light directly below. In order to separate the vibration caused by the movement of the work stage 83 and the vibration caused by the cooling of the light irradiator 2, the irradiator installation stand 82 is not fixed to the stage conveyance stand 81, but with the stage conveyance stand 81. It may be configured separately. The stage transport rack 81 and the irradiator installation rack 82 may have a vibration isolation structure.
The stage transport stand 81 is internally provided with a linear motion mechanism 84 (not shown) for transferring the work stage 83 so as to pass directly below the light irradiator 2 on the surface of the stage transport stand 81 along the linear motion direction X. It is done. In the light alignment of the light alignment object W, the light alignment object W placed on the work stage 83 is transported along the linear movement direction X by the linear movement mechanism 84 and the position directly below the light irradiator 2 is determined. The light passes through and is exposed to polarized light during this pass to orient the photoalignment film. In the present embodiment, the light alignment object W is formed in a rectangular shape in plan view, and is transported so that the short direction of the light alignment object W coincides with the linear movement direction X.

As shown in FIGS. 2 and 3, the light irradiator 2 is provided with a lamp 4 and a reflecting mirror (elliptic mirror) 5 serving as a light source in a housing 3 having a light emission opening 3A on the lower surface, and a light emission opening A polarizer unit 10 is provided at 3A.
The housing 3 is supported by the irradiator installation rack 82 at an upper position away from the light orientation object W by a predetermined distance. The lamp 4 is a discharge lamp, and a straight tube (rod-like) ultraviolet lamp extending at least equal to the length in the longitudinal direction of the light alignment object W is used. The reflecting mirror 5 is a cylindrical concave reflecting mirror having an elliptical cross section and extending along the longitudinal direction of the lamp 4, and condenses the light of the lamp 4 and irradiates it from the light emitting opening 3A toward the polarizer unit 10. .

The light emitting opening 3 A is a rectangular opening in a plan view formed directly below the lamp 4, and the light emitting opening 3 A is provided such that the longitudinal direction coincides with the longitudinal direction of the lamp 4.
The light emitting opening 3A is provided with a plate-like transparent body 6 formed of a light transmitting member having no filter characteristic (wavelength selection characteristic) such as a quartz plate, for example. 3A is blocked.
In addition, a wavelength selection filter 7 for selecting the wavelength of light to be transmitted is provided inside the light emission opening 5B of the reflecting mirror 5, specifically, inside the light emission opening 3A. 2 is adapted to emit light of a desired wavelength.

The polarizer unit 10 is disposed between the transparent body 6 and the light alignment object W, and polarizes the light irradiated to the light alignment object W. The polarized light is irradiated to the photoalignment film of the photoalignment object W, whereby the photoalignment film is aligned.
As shown in FIG. 4, the polarizer unit 10 includes a plurality of unit polarizer units 12 and a frame 14 for aligning the unit polarizer units 12 in a row and in a row. The frame 14 is a plate-like frame on which the unit polarizer units 12 are arranged in a connected manner. The unit polarizer unit 12 includes a wire grid polarizer (polarizer) 16 formed in a substantially rectangular plate shape.
In this embodiment, each unit polarizer unit 12 supports the wire grid polarizer 16 so that the wire direction A is parallel to the linear movement direction X, and a direction orthogonal to the wire direction A, a wire grid polarizer The arrangement direction B of 16 is made to correspond.

The wire grid polarizer 16 is a kind of linear polarizer, and a wire grid is formed on the surface of a substrate. As described above, since the lamp 4 is rod-shaped, light of various angles is incident on the wire grid polarizer 16, but the wire grid polarizer 16 is linearly polarized even if it is obliquely incident light Through.
The wire grid polarizer 16 is supported by the unit polarizer unit 12 so that the direction of the polarization axis C1 can be finely adjusted by rotating in a plane with the normal direction as the rotation axis. That is, the plurality of wire grid polarizers 16 are arranged with a gap therebetween so that the direction of the polarization axis C1 can be finely adjusted. The polarization axis C1 of the wire grid polarizer 16 is finely adjusted to align in a predetermined illumination reference direction for all unit polarizer units 12, so that the polarization axis C1 is extended over the entire length in the long axis direction of the polarizer unit 10. However, it is possible to obtain polarized light aligned with high accuracy, and to achieve high-quality photo-alignment. The wire grid polarizer 16 whose polarization axis C1 is adjusted is fixed to the frame 14 by fixing the upper end and the lower end of the unit polarizer unit 12 to the frame 14 with screws (fixing means) 19.

Further, as shown in FIGS. 2 and 3, the light alignment device 1 is provided with a blower cooling unit 20 for cooling the lamp 4, the reflecting mirror 5, the wavelength selection filter 7 and the polarizer unit 10. The blower cooling unit 20 is provided with a heat source cooling path 30 for cooling the lamp 4 and the reflecting mirror 5 and a polarizer cooling path 40 for cooling the polarizer unit 10 independently of each other.
In each of the heat source cooling path 30 and the polarizer cooling path 40, the fans 21, 21 for blowing the cooling air, the coolers 22, 22 for cooling the cooling air, and foreign substances such as dust contained in the cooling air are removed. Filters 23, 23 are provided. The blower 21 is disposed upstream of the cooler 22. Thereby, the cooling air cooled by the cooler 22 can be prevented from being reheated by the heat source of the blower 21. In this embodiment, the blower 21 is used as the blower 21, the water cooled radiator is used as the cooler 22, and the HEPA (High Efficiency Particulate Air) filter is used as the filter 23. However, the blower 21, the cooler 22, and the filter 23 It is not limited to the configuration.

  In the heat source cooling path 30, the blower 21, the cooler 22 and the filter 23 are accommodated in a cooling unit case 20 </ b> A provided outside the housing 3. In the present embodiment, the cooling unit case 20A is disposed above the housing 3 so as to be separated from the housing 3, but the arrangement position of the cooling unit case 20A is not limited to this. A chamber 24 is provided in the cooling unit case 20A, and a blowout port 21A of the blower 21 and an inlet 24A of the chamber 24 are connected by a duct 25. The chamber 24 is expanded in diameter toward the downstream side from the inlet 24A, and a cooler 22 is disposed upstream of the chamber 24 and a filter 23 is disposed downstream thereof. The outlet 24B of the chamber 24 and the housing 3 are connected by a duct 26, and the suction port 21B of the blower 21 and the housing 3 are connected by a duct 27.

In the housing 3, a partition 31 surrounding the sides of the lamp 4 and the reflecting mirror 5 is provided with a gap δ1 between the housing 3 and the housing 3. The partition wall 31 has an opening 31A at the lower part, which exposes the lamp 4 and the reflecting mirror 5 downward, and a ventilation hole 31B at the upper part.
The duct 26 is connected to the housing 3 at a position corresponding to the gap δ 1 outside the partition 31, and the duct 27 is connected to the housing 3 at a position corresponding to the space R inside the partition 31.
The blower 21, the duct 25, the chamber 24 (cooler 22, the filter 23), the duct 26, the gap δ1 outside the partition 31, and the space R inside the partition 31 and the duct 27 constitute a heat source cooling path 30.

In the heat source cooling path 30, the cooling air (air) blown out from the blower 21 flows into the chamber 24 through the duct 25, is cooled by the cooler 22, and the foreign matter is removed by the filter 23. The cooling air is dehumidified by the filter 23 so that the dew point is about −50 ° C. to −90 ° C. or less, and the foreign matter is removed to become low dew point high cleanliness air (clean dry air). The cooling air that has become clean dry air is supplied into the housing 3 via the duct 26.
In the housing 3, the cooling air passes through the gap δ 1 between the partition 31 and the housing 3, flows through the gap δ 2 between the partition 31 and the transparent body 6, and the inside of the reflecting mirror 5 and the reflecting mirror 5. And flow into the space R in the partition 31 to cool the lamp 4 and the reflecting mirror 5. The cooling air whose temperature is increased by cooling the lamp 4 and the reflecting mirror 5 flows from the through hole 5A formed in the upper part of the reflecting mirror 5 and from the outside of the reflecting mirror 5 to the space R in the partition 31 The air is sucked into the blower 21 through the duct 27 and cooled again. Thus, the cooling air circulates through the heat source cooling path 30.

Also in the polarizer cooling path 40, the blower 21 and the cooler 22 and the filter 23 arranged in the chamber 24 are disposed in the cooling unit case 20A, and the outlet 21A of the blower 21 and the inlet 24A of the chamber 24 are ducts. Connected by 25.
Further, the outlet 24B of the chamber 24 and the housing 3 are connected by a duct 28, and the suction port 21B of the blower 21 and the housing 3 are connected by a duct 29.

  The duct 28 is an extending portion 28A extending over the light emitting opening 3A of the housing 3, more specifically, the length of the polarizer unit 10 in the longitudinal direction, and a diameter reduction from the extending portion 28A And a unit 28B. The reduced diameter portion 28 B is connected to the outlet 24 B of the chamber 24, and the extension portion 28 A is connected to the housing 3. Similarly, the duct 29 is reduced in diameter from the extending portion 29A which extends over the light emitting opening 3A of the housing 3, more specifically, the longitudinal length of the polarizer unit 10, and the extending portion 29A. And a reduced diameter portion 29B. The reduced diameter portion 29 </ b> B is connected to the suction port 21 </ b> B of the blower 21, and the extension portion 29 </ b> A is connected to the housing 3. The extension portion 28A and the extension portion 29A are supported by the housing 3 via the plate-like support members 28C and 29C.

The polarizer unit 10 is provided on the outside of the housing 3 at a position facing the light emitting opening 3A with the transparent body 6 and the space S open, and the frame 14 is fixed to the polarizer unit fixing base 8. Ducts 28 and 29 are connected between the housing 3 and the polarizer unit fixing base 8. The duct 28 is connected to one end side in the linear movement direction X, and the duct 29 is connected to the other end side in the linear movement direction X.
The blower 21, the duct 25, the chamber 24 (cooler 22, the filter 23), the duct 28, the space S between the transparent body 6 and the polarizer unit 10, and the duct 29 constitute a polarizer cooling path 40. That is, the polarizer cooling path 40 constitutes a space cooling path for cooling the space S between the transparent body 6 and the polarizer unit 10.

  In the polarizer cooling path 40, the cooling air blown out from the blower 21 flows into the chamber 24 through the duct 25, is cooled by the cooler 22, and the foreign matter is removed by the filter 23 through the duct 28. Flows into the space S between the transparent body 6 and the polarizer unit 10 to cool the polarizer unit 10. At this time, the cooling air having flowed into the space S flows so as to be orthogonal to the longitudinal direction of the lamp 4. The cooling air whose temperature has risen by cooling the polarizer unit 10 is sucked into the blower 21 through the duct 29 and cooled again. Thus, the cooling air circulates through the polarizer cooling path 40.

Further, since the polarizer cooling path 40 is completely independent of the heat source cooling path 30, the lamp 4 and the polarizer can be controlled by controlling the temperature of the cooling air flowing through the heat source cooling path 30 and the polarizer cooling path 40, respectively. The units 10 can be cooled individually.
At this time, the blowers 21 and 21 are individually controlled, the wind speed of the cooling air of the heat source cooling path 30 is relatively slow, and the wind speed of the cooling air of the polarizer cooling path 40 is set relatively fast. And the polarizer unit 10 can be cooled at a relatively low temperature. Thereby, the lamp 4 and the polarizer unit 10 can be properly cooled.
Moreover, the duct 28 for supplying the cooling air to the space S between the transparent body 6 and the polarizer unit 10 and the duct 29 for discharging the cooling air from the space S extend over the length of the polarizer unit 10 in the longitudinal direction. Because of the presence, the entire polarizer unit 10 can be cooled substantially uniformly.

In the present embodiment, the fans 21 and 21 are individually controlled to individually control the temperature of the cooling air flowing through the heat source cooling path 30 and the polarizer cooling path 40, but the cooling temperature in the coolers 22 and 22 May be set to different temperatures.
In the present embodiment, the heat source cooling path 30 and the polarizer cooling path 40 are completely independent, but a part of the heat source cooling path 30 and the polarizer cooling path 40, for example, the blower 21, the cooler 22, and the filter At least one of twenty-three may be common. Furthermore, although the cooling air of the heat source cooling path 30 and the polarizer cooling path 40 is circulated in the present embodiment, the cooling air does not necessarily have to be circulated.

By the way, outgas may be generated from the alignment film during processing (during irradiation) of the photo alignment object W. Further, in the environment in which the light alignment device 1 is disposed, foreign matter such as paper dust is also present. If foreign matter such as this outgas is mixed or attached to the wire grid polarizer 16, the polarization characteristics of the wire grid polarizer 16 are changed and adversely affected.
Therefore, in the present embodiment, the light alignment device 1 is provided with a positive pressure mechanism 50 that applies a positive pressure to the space S between the transparent body 6 and the polarizer unit 10. More specifically, the duct 29 connecting the suction port 21B of the blower 21 to the housing 3 is provided with a flow rate adjusting unit 51 configured of, for example, a damper. By throttling the flow rate of the cooling air flowing through the duct 29 located downstream of the space S using the flow rate adjusting means 51, the space S between the transparent body 6 and the polarizer unit 10 can be set to a positive pressure.

When the space S has a positive pressure, the cooling air is blown out from the gap of the polarizer unit 10, so that foreign matter can be prevented from entering the polarizer cooling path 40 from the gap of the polarizer unit 10. . This makes it possible to reliably prevent foreign matter from adhering to or entering the polarizer unit 10.
As the gap of the polarizer unit 10, for example, a gap between the frame 14 of the polarizer unit 10 and the polarizer unit fixing table 8 or a gap between the plurality of wire grid polarizers 16 may be mentioned. Therefore, the foreign matter can be reliably prevented from entering the polarizer cooling path 40 without providing a means for airtightly closing these gaps, so the number of parts of the light alignment device 1 can be reduced and the manufacturing process can be simplified.

Further, the duct 29 is formed with an inlet 52 for introducing air from the outside. Since air is introduced from the outside by the amount blown out from the gap of the polarizer unit 10 through the inlet 52, it is possible to prevent the negative pressure in the polarizer cooling path 40 from becoming too negative, and the blower 21 becomes efficient. I can drive well. In the present embodiment, the inlet 52 is provided downstream of the flow rate adjusting means 51, but the inlet 52 can be provided at any position as long as it is upstream of the cooler 22 and the filter 23.
The flow rate adjusting means 51 and the inlet 52 constitute the positive pressure mechanism 50 of the present embodiment.
In the present embodiment, the positive pressure mechanism 50 is provided in the duct 29 connecting the suction port 21B of the blower 21 and the housing 3 in the polarizer cooling path 40, but the suction port 21B of the blower 21 and the housing 3 And may be simply connected by a duct 29.

  A transparent body (light transmitting member) 70 for protecting the polarizer unit 10 is provided on the light emission side of the polarizer unit 10. The transparent body 70 is, for example, a plate-like light transmitting member having no filter characteristic (wavelength selection characteristic) such as a quartz plate. The transparent body 70 is provided on the light emission side of the polarizer unit 10, and the polarizer unit 10 is covered by the transparent body 70. Specifically, a rectangular frame 8A is formed on the polarizer unit fixing base 8 below the polarizer unit 10 in plan view, and the transparent body 70 is supported in the frame 8A. Thereby, a space T partitioned by the polarizer unit 10 and the transparent body 70 is formed in the polarizer unit fixing base 8.

There are several types of materials for the photoalignment film, and it has been found that the characteristics of the liquid crystal panel are excellent when using a photoalignment film oriented with light having a main wavelength of 365 nm.
Since the wavelength range around 365 nm is also ultraviolet light, it is necessary to use a wire grid polarizer that transmits ultraviolet light efficiently and does not deteriorate with ultraviolet light. For example, although a wire grid polarizer intended to polarize light of 300 nm or more is known, since the wire grid is formed of aluminum (Al), the wire grid is formed by the heat of ultraviolet light. It will oxidize and deteriorate. In order to prevent this deterioration, a large-scale measure such as an N ₂ purge device for feeding nitrogen into the surrounding space is required. On the other hand, in the wire grid polarizer in which the wire grid is formed of titanium oxide, although it is resistant to ultraviolet light, good polarization characteristics can not be obtained with light of 300 nm or more.
So, in this embodiment, the wire grid polarizer 16 is comprised as follows.

FIG. 5 is a schematic view showing the wire grid polarizer 16.
In the wire grid polarizer 16, as shown in FIG. 5, a plurality of wire grids 16B are formed in parallel at a predetermined pitch P on a base 16A. The base 16A is made of, for example, quartz, and the wire grid 16B is made of Si (silicon). The wire grid 16B is covered with a covering layer 16C of a mixed material of silicon oxide and aluminum oxide by trench filling.

  FIG. 6 is a view showing the durability of the wire grid polarizer 16 according to the polarization transmittance. In FIG. 6, the horizontal axis shows elapsed time (time), and the vertical axis shows polarized light transmission (%) for light of wavelength 365 nm. FIG. 7 is a view showing the durability of the wire grid polarizer 16 according to the extinction ratio. In FIG. 7, the horizontal axis indicates an elapsed time (time), and the vertical axis indicates a change ratio (%) of the extinction ratio to light with a wavelength of 365 nm. Moreover, in FIG.6 and FIG.7, code | symbol A shows the result of the wire grid polarizer which formed the wire grid by Al as a result of the wire grid polarizer which formed the wire grid by Si as mentioned above.

As shown in FIG. 6, the wire grid polarizer 16 has sufficient transmittance (70% or more) for light of 365 nm. In addition, as shown in FIG. 7, the wire grid polarizer 16 shows almost no change in the extinction ratio even after approximately 300 hours, as compared with the conventional wire grid polarizer using Al, and the durability is high. have.
As described above, the wire grid 16B is formed of Si, and the wire grid 16B is covered with the covering layer 16C of a mixed material of silicon oxide and aluminum oxide, so that ultraviolet rays are efficiently transmitted while deterioration of the wire grid 16B due to ultraviolet light is achieved. It can be suppressed.
In the present embodiment, the wavelength selection filter 7 uses a filter that transmits light with a wavelength of 320 to 450 nm.

Moreover, as a lamp | ramp which radiate | emits the light of wavelength 365 nm vicinity, there exist a high pressure mercury lamp and a metal halide lamp, for example.
FIG. 8 is a diagram showing a relative spectral distribution of the high pressure mercury lamp, and FIG. 9 is a diagram showing a relative spectral distribution of the metal halide lamp. In FIG. 8 and FIG. 9, the horizontal axis indicates the wavelength (nm), the left vertical axis indicates the relative intensity (%), and the right vertical axis indicates the extinction ratio. Further, in FIG. 8 and FIG. 9, bar graphs indicate relative intensities, dotted graphs indicate extinction ratios of the wire grid polarizer 16, and solid graphs indicate spectral transmittances of the wavelength selection filter 7.
As shown in FIGS. 8 and 9, although both high-pressure mercury lamps and metal halide lamps emit light near a wavelength of 365 nm, metal halide lamps emit more light having a wavelength of 320 to 450 nm, which is transmitted by the wavelength selection filter 7 Radiate.
Therefore, in the present embodiment, the illuminance is improved by using a metal halide lamp as the lamp 4.

As shown in FIG. 9, a wavelength range (for example, 400 nm) having a relatively low extinction ratio overlaps the transmission wavelength range of the wavelength selection filter 7.
Here, an interference film filter is used as the wavelength selection filter 7. The interference film filter has incident angle dependency in transmission characteristics, and the transmission wavelength range shifts to the short wavelength side as the incident angle of light increases.
In the present embodiment, since a rod-like lamp is used as the lamp 4, the component of light having a large incident angle (for example, 10 ° or more) is also relatively large. Therefore, even if the wavelength range (for example, 400 nm) having a relatively low extinction ratio overlaps the transmission wavelength range of the wavelength selection filter 7, good polarization characteristics can be obtained as shown in FIGS.

Further, in recent years, the integrated light quantity may be required to be high in order to improve the production capacity, and there is a method of, for example, increasing the lamp load (power density) in order to meet this demand. On the other hand, it is difficult to increase the area of the wire grid polarizer. Therefore, if the lamp load is increased with respect to the wire grid polarizer of the same area, the amount of light passing through the wire grid polarizer also increases and the temperature of the wire grid polarizer increases, so it is necessary to further cool the wire grid polarizer There is. For example, the wire grid polarizer 16 formed as described above has a heat resistant temperature of about 200.degree.
So, in this embodiment, in order to further cool the wire grid polarizer 16, in addition to the blower cooling unit 20, the compressed air cooling unit 60 is provided.

As shown in FIG. 3, the compressed air cooling unit 60 supplies air to the space S partitioned by the transparent body 6 and the polarizer unit 10 and to the space T partitioned by the polarizer unit 10 and the transparent body 70, respectively. Ports 61 and 62 are provided.
The air supplied to the air supply ports 61 and 62 is dehumidified so that the dew point is about −50 ° C. to −90 ° C. or less, and the foreign matter is removed, and the low dew point high cleanliness air (clean dry air) It is. It is to be noted that a gas other than clean dry air, for example, an inert gas such as nitrogen may be used if it has the same low dew point and high cleanliness and transmits ultraviolet light. The air supplied to the air supply ports 61 and 62 may be supplied from equipment of a factory where the light alignment device 1 is installed, or may be supplied from separately provided air generating means (for example, a cylinder, a compressor). May be Further, the air supplied to the air supply ports 61 and 62 may be branched from the blower cooling unit 20, and may be supplied by providing a compressor (not shown) downstream of the branch.

The air supply ports 61 and 62 extend in the longitudinal direction of the lamp 4 and are provided with a plurality of outlets 61 A and 62 A in the longitudinal direction of the lamp 4. The air outlets 61A and 62A are provided at predetermined intervals over the length of the polarizer unit 10 in the longitudinal direction.
In the present embodiment, a plurality of blowout ports 61A, 62A are provided, but one blowout port 61A, 62A may be provided along the length of the polarizer unit 10 in the longitudinal direction. The air supply ports 61 and 62 may be fixed to the housing 3 or may be fixed to the irradiator installation rack 82 that supports the housing 3.

  The air supplied to the air supply ports 61 and 62 is blown toward the upper and lower surfaces of the polarizer unit 10 from the blowout ports 61A and 62A provided along the longitudinal direction of the polarizer unit 10. Thereby, in addition to the cooling air by the blower cooling unit 20, the compressed air of the compressed air cooling unit 60 is sprayed to the polarizer unit 10, so that the polarizer unit 10 can be cooled more, and as a result, the polarization characteristic is maintained. it can.

  Further, by providing the air supply ports 61 and 62 in the spaces S and T, respectively, the spaces S and T have positive pressure. When the space T has a positive pressure, air is blown out from the gap between the transparent body 70 and the polarizer unit fixing base 8 (hereinafter referred to as a gap between the transparent body 70), so the transparent body 70 and Foreign matter can be prevented from entering the space T from the gap with the polarizer unit fixing base 8. This makes it possible to reliably prevent foreign matter from adhering to or entering the polarizer unit 10. Thus, the foreign matter can be reliably prevented from entering the space T and the polarizer cooling path 40 without providing a means for airtightly closing the gap of the transparent body 70 and the gap of the polarizer unit 10. As a result, the number of parts of the optical alignment device 1 can be reduced, and the manufacturing process can be simplified.

  As described above, according to the present embodiment, the light alignment device 1 accommodates the lamp 4 (metal halide lamp) in the reflecting mirror 5, and at least the light having a wavelength of 320 to 450 nm in the exit 5B of the reflecting mirror 5. A wavelength selective filter 7 for transmitting light is disposed, and the wire grid polarizer 16 of light transmitted through the wavelength selective filter 7 is a Si wire grid 16B formed on a base 16A, and a mixture of silicon oxide and aluminum oxide is formed by trench filling. It was set as the structure provided with the wire grid polarizer 16 which covered and formed Si wire grid with material. By forming the Si wire grid 16B on the base 16A and covering the Si wire grid 16B with a mixed material of silicon oxide and aluminum oxide, good polarization characteristics can be obtained even with light in the ultraviolet region of 300 nm or more as the polarization target. In addition, by using the wavelength selection filter 7 that transmits light with a wavelength of 320 to 450 nm, the polarization characteristic is further improved. Furthermore, the illuminance can be improved by using a metal halide lamp that emits a large amount of light in the vicinity of a wavelength of 365 nm as the lamp 4.

However, the above-mentioned embodiment is one mode of the present invention, and it is needless to say that it can be suitably changed in the range which does not deviate from the meaning of the present invention.
For example, in the above-mentioned embodiment, the metal halide lamp was used for the lamp, but the lamp is not limited to this. For example, a high pressure mercury lamp may be used for the lamp. In particular, a lamp that emits light near a wavelength of 365 nm is desirable. For example, a lamp that emits light with a wavelength of 300 nm or more (a wavelength of more than 300 nm), specifically light with a wavelength in the range of 320-450 nm, more preferably light with a wavelength in the range of 340-400 nm It may be.
Moreover, in the above-mentioned embodiment, although the filter which permeate | transmits the light of a wavelength of 320-450 nm is used for the wavelength selection filter 7, you may use the filter which permeate | transmits the light of wavelength 340-400 nm.

Moreover, in the above-mentioned embodiment, although the wire grid 16B was formed by Si (silicon), the trace material other than a metal oxide etc. may be included in the material of a wire grid.
Moreover, in the above-mentioned embodiment, although the polarizer unit 10 was comprised by the several wire grid polarizer 16, one wire grid polarizer 16 may be sufficient.

  In the above embodiment, although the blower cooling unit 20 and the compressed air cooling unit 60 are provided, when the output of the lamp 4 is low and the polarizer unit 10 does not need to be cooled, the blower cooling unit 20 and / or Alternatively, the compressed air cooling unit 60 may be omitted.

1 light alignment device 4 lamp (metal halide lamp)
5 Reflector (elliptic mirror)
5B Exit 7 wavelength selection filter (filter)
16 Wire grid polarizer (polarizer)
16B wire grid

Claims (2)

A metal halide lamp or a high pressure mercury lamp is housed in an elliptical mirror,
A filter that transmits light of at least 320 to 450 nm is disposed at the exit of the elliptical mirror,
A polarizer for polarizing light transmitted through the filter, comprising a Si wire grid formed on a substrate, and a polarizer formed by covering the Si wire grid with a mixed material of silicon oxide and aluminum oxide by trench filling An optical alignment device characterized in that   The optical alignment device according to claim 1, wherein the filter is a filter that transmits light of a wavelength of 340 to 400 nm.

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