JP6187348B2 - Polarized light irradiation device - Google Patents

Description

  Embodiments described herein relate generally to a polarized light irradiation apparatus used for manufacturing a liquid crystal panel.

  A rubbing process is known as a technique for performing alignment processing of an alignment film during the manufacture of a liquid crystal panel or the like, but in recent years, the alignment film is irradiated with polarized light having a predetermined wavelength as a technique that replaces the rubbing process. A so-called photo-alignment technique, in which the alignment treatment is performed, is drawing attention. As a polarized light irradiation apparatus that is an apparatus for performing this photo-alignment, for example, a polarized light irradiation apparatus that combines a rod-shaped lamp that is a linear light source and a wire grid polarization element having a wire grid grid. Proposed.

  In the wire grid polarization element, the dependence of the extinction ratio of the polarized light emitted with respect to the angle of the light incident on the polarization element is smaller than that of the polarization element using the vapor deposition film or the Brewster angle. For this reason, even with divergent light such as light emitted from a rod-shaped lamp, if the incident angle is within a range of ± 45 °, polarization with a relatively good extinction ratio over the entire region irradiated with light Light can be obtained. Therefore, in such a polarized light irradiation apparatus, the length of the rod-shaped lamp is made to correspond to the width of the alignment film that is the object to be processed. By unilaterally moving, it is possible to perform alignment treatment of an alignment film having a large area with a single rod-shaped lamp.

JP 2009-265290 A JP 2011-145382 A

  Here, such a polarized light irradiation apparatus is configured to be able to irradiate light with as much light as possible on the irradiation surface of the alignment film. Specifically, from the rod-shaped lamp, By condensing the light on the polarizing element, the irradiation loss to the outside of the polarizing element is suppressed. However, when the light from the rod-shaped lamp is condensed on the polarizing element in this way, the polarized light transmitted through the polarizing element diffuses. And in the irradiated surface where the diffused polarized light is irradiated, the polarized light spreads more than the area of the polarizing element. It is known that the polarization axis of polarized light irradiated to a position wider than the area of the polarizing element deteriorates. If the light whose polarization axis is deteriorated is irradiated on the alignment film, which is an object to be irradiated, the characteristics of the alignment film are deteriorated.

  This invention is made | formed in view of the above, Comprising: It aims at providing the polarized light irradiation apparatus which suppresses that the polarized light in which the polarization axis characteristic fell outside the irradiation range.

  The polarized light irradiation apparatus of the embodiment includes a light source, a filter, a polarizing element, a polarizing element holding unit, and a light shielding plate. The light source emits light. The filter is irradiated with light emitted from the light source and emits ultraviolet rays. The polarizing element is disposed on the side of the filter facing the light source, and receives ultraviolet rays and emits polarized light. The polarizing element holding unit has an opening that holds the polarizing element and transmits the polarized light emitted from the polarizing element. The light shielding plate is disposed on the side of the polarizing element holding portion facing the light source, and is disposed so as to surround the opening.

  According to the present invention, it is possible to suppress a decrease in polarization axis characteristics outside the irradiation range.

FIG. 1 is an exploded perspective view illustrating a configuration of a polarized light irradiation apparatus according to the first embodiment. FIG. 2 is a cross-sectional view taken along the line AA along the one-dot chain line AA of the polarized light irradiation apparatus shown in FIG. FIG. 3 is an explanatory view showing a light irradiation state in the polarized light irradiation apparatus shown in FIG. FIG. 4 is an explanatory diagram of a polarized light irradiation apparatus that does not include a light shielding plate. FIG. 5 is a chart of test results of the irradiation state of polarized light. FIG. 6 is a cross-sectional view of the polarized light irradiation apparatus according to the second embodiment when viewed in the X-axis direction. FIG. 7 is a BB arrow view of FIG. FIG. 8 is a view taken along the line CC in FIG. FIG. 9 is a modified example of the polarized light irradiation apparatus according to the second embodiment, and is an explanatory diagram when the light shielding plate is viewed in the Y-axis direction. FIG. 10 is a view taken along the line DD in FIG.

  The polarized light irradiation apparatuses 1 and 40 according to the embodiments described below include a light source 5, a filter 20, a polarizing element 25, a polarizing element holding unit 26, and light shielding plates 30 and 50. The light source 5 emits light. The filter 20 is irradiated with light emitted from the light source 5 and emits ultraviolet rays. The polarizing element 25 is disposed on the side of the filter 20 facing the light source 5, and receives ultraviolet rays and emits polarized light. The polarizing element holding unit 26 holds the polarizing element 25 and has an opening 27 that transmits polarized light. The light shielding plates 30 and 50 are disposed on the side of the polarizing element holding unit 26 facing the light source 5 and are disposed so as to surround the opening 27.

  Further, in the polarized light irradiation apparatus 40 according to the embodiment described below, a transparent member that closes the space inside the light shielding plate 50 at the end of the light shielding plate 50 opposite to the side where the opening 27 is located. A glass plate 52 is provided.

  Further, in the polarized light irradiation device 40 according to the embodiment described below, the light shielding plate 50 has air supply / exhaust portions 55 formed at a plurality of locations.

Embodiment 1
Next, the polarized light irradiation apparatus according to the first embodiment will be described with reference to the drawings. FIG. 1 is an exploded perspective view illustrating a configuration of a polarized light irradiation apparatus according to the first embodiment. 2 is a cross-sectional view of the polarized light irradiation apparatus shown in FIG. 1 as viewed in the X-axis direction. The polarized light irradiation apparatus 1 shown in the figure is used for manufacturing, for example, an alignment film of a liquid crystal panel and an alignment film of a viewing angle compensation film. The reference direction of the polarization axis of the ultraviolet light irradiated on the surface of the workpiece W that is the object to be processed is appropriately set according to the structure, application, or required specification of the workpiece W. Hereinafter, the width direction of the workpiece W is referred to as the X-axis direction, orthogonal to the X-axis direction, and the longitudinal direction of the workpiece W (also referred to as the conveyance direction) is referred to as the Y-axis direction, and orthogonal to the Y-axis direction and the X-axis direction This direction is called the Z-axis direction.

  The polarized light irradiation apparatus 1 according to the first embodiment reflects a light source 5 that emits light including ultraviolet rays, a reflection plate 10 that controls light distribution of light emitted from the light source 5, and the reflection plate 10. A filter that is arranged on the traveling direction side of the light whose light distribution is controlled by the plate 10 and that emits ultraviolet rays when the light emitted from the light source 5 and the light whose light distribution is controlled by the reflecting plate 10 are incident. 20, a polarizing element 25 that is disposed on the output side of the filter 20 and that emits polarized light when ultraviolet light emitted from the filter 20 is incident thereon, and a polarizing element holding unit 26 that holds the polarizing element 25. .

  The light source 5 is a rod-shaped or linear light source. The light source 5 is, for example, a high-pressure mercury lamp in which a rare gas such as mercury, argon, or xenon is sealed in a glass tube that transmits ultraviolet light, or a metal halide lamp in which a metal halide such as iron or iodine is further sealed in a high-pressure mercury lamp. The tube lamp has a linear light emitting portion. The longitudinal direction of the light emitting part of the light source 5 is parallel to the X-axis direction, and the length of the light emitting part of the light source 5 is longer than the width of the workpiece W. The light source 5 can emit light including ultraviolet rays having a wavelength of 200 nm to 400 nm, for example, from a linear light emitting unit, and the light emitted from the light source 5 has various polarization axis components. It is unpolarized light.

  In addition, the reflecting plate 10 has a reflecting surface 11 that reflects light emitted from the light source 5 on a surface facing the light source 5. The reflecting surface 11 has a shape as viewed in the axial direction as viewed in the direction along the axial center of the light source 5 formed in a rod shape, that is, a shape in the X-axis direction, and a part of an ellipse is opened. It has a shape. The reflector 10 is provided so that the lamp center C, which is the axis of the light source 5, is located at one of the two elliptical focal points of the reflecting surface 11, and the other focal side is open. Yes. Since the reflecting surface 11 has a shape of a part of an ellipse in this way, the reflecting plate 10 allows light emitted from the light source 5 to be focused on the other focal point when the light source 5 is arranged at the position of one focal point. This is a so-called concentrating reflector that condenses near (focal point F in FIG. 3). Further, the reflecting plate 10 is disposed in an orientation that opens in the Z-axis direction.

  The reflector 10 extends in parallel with the light source 5 in these shapes along the light source 5 formed in a rod shape. Further, the reflecting plate 10 is a gap in the circumferential direction of the ellipse or in the Y-axis direction near the portion where the curvature of the ellipse is maximized on the opposite side of the reflecting surface 11 where the ellipse is open. A gap 12 is formed. That is, the gap 12 is formed on the side opposite to the side where the ellipse of the reflecting surface 11 is opened in the Z-axis direction when viewed from the light source 5. The reflector 10 communicates the space between the inner side and the outer side of the ellipse at the gap 12. The reflector 10 is configured as a cold mirror in which the base material is made of glass and the reflecting surface 11 is formed by a multilayer film. When the polarized light irradiation device 1 irradiates the irradiated object with the polarized light, the light source 5 emits light while generating heat, but the air whose temperature has been increased by this heat flows upward, and from the gap 12 to the reflector 10. Exit upwards. Thereby, the polarized light irradiation apparatus 1 irradiates the work W with ultraviolet rays without the temperature becoming too high.

  The filter 20 is a well-known bandpass filter that transmits only a specific wavelength of light emitted from the light source 5, and has a predetermined wavelength such as 254 nm or 365 nm among the light emitted from the light source 5. It is possible to restrict the transmission of light of other wavelengths while transmitting ultraviolet light. The filter 20 is disposed on the side where the ellipse of the reflecting surface 11 is open in the Z-axis direction with respect to the light source 5 and the reflecting plate 10. The filter 20 is surrounded by a filter frame 21 in the X-axis direction and the Y-axis direction, so that the filter 20 is held by the filter frame 21.

  Similar to the filter 20, the polarizing element 25 is arranged on the side where the ellipse of the reflecting surface 11 is open in the Z-axis direction with respect to the light source 5 and the reflecting plate 10. The reflection plate 10 which is a condensing type reflection plate is provided so that the light can be condensed on the polarizing element 25.

  The polarizing element 25 is a wire grid polarizing element in which a plurality of linear electric conductors (for example, metal wires such as chromium and aluminum alloy) are arranged in parallel at equal intervals on a substrate such as quartz glass. The longitudinal direction of the electrical conductor is orthogonal to the reference direction. It is desirable that the pitch of the electric conductors is 1/3 or less of the wavelength of the ultraviolet rays emitted from the light source 5. The polarizing element 25 reflects or absorbs most of the ultraviolet rays having a polarization axis parallel to the longitudinal direction of the electric conductor among the ultraviolet rays emitted from the filter 20 when the light emitted from the light source 5 enters. Ultraviolet rays having a polarization axis perpendicular to the longitudinal direction of the conductor are passed through and irradiated toward the workpiece W. The polarizing element 25 can extract, as polarized light, ultraviolet light having a polarization axis that vibrates only in the reference direction from ultraviolet light emitted from the filter 20 disposed between the light source 5 and the polarizing element 25. Further, the polarizing element 25 can extract light having a polarization axis oscillated only in the reference direction from light having various polarization axis components emitted from the light source 5 and uniformly oscillated in all directions. Note that light having a polarization axis that vibrates only in the reference direction is generally referred to as linearly polarized light. The polarization axis is the vibration direction of the electric field and magnetic field of light.

  The polarizing element holding unit 26 holds the polarizing element 25 that receives ultraviolet light and emits polarized light, and has an opening 27 that transmits the polarized light emitted from the polarizing element 25. In addition, the polarizing element 25 is surrounded by the polarizing element holding unit 26 around the X axis direction and the Y axis direction, whereby the polarizing element 25 is held by the polarizing element holding unit 26.

  In the first embodiment, the polarizing element 25 is arranged such that the longitudinal direction of the electric conductor is parallel to the Y-axis direction, and allows ultraviolet rays having a polarization axis parallel to the X-axis direction to pass therethrough. That is, in the first embodiment, the reference direction is parallel to the X-axis direction.

  Further, a light shielding plate 30 is provided on the side of the polarizing element holding unit 26 facing the light source 5. The light shielding plate 30 is disposed so as to surround the opening 27 of the polarizing element holding unit 26. Specifically, the polarizing element 25 is formed in a rectangular plate shape, and the opening 27 formed in the polarizing element holding unit 26 that holds the polarizing element 25 also corresponds to the polarizing element 25 in the same manner as the polarizing element 25. It is formed in a rectangular shape.

  The light shielding plate 30 is located on the polarized light exit side of the opening 27 of the polarizing element holding unit 26 and protrudes from the polarizing element holding unit 26 in the direction opposite to the direction in which the light source 5 and the like are located. When viewed in the opening direction, it is disposed so as to surround the opening 27. That is, the light shielding plate 30 is formed in a substantially rectangular tube shape whose inner shape is slightly larger than the opening 27, and surrounds the entire rectangular opening 27 from four directions when viewed in the Z-axis direction. In addition, the rectangular tube is arranged in such a direction that the axial direction of the rectangular tube becomes the Z-axis direction. For this reason, the light shielding plate 30 is open at the end facing the polarizing element holding part 26. The light shielding plate 30 provided in this way is formed as a light shielding plate reflecting surface 31 whose inner surface reflects light when an aluminum foil or the like is provided, for example.

  In addition, it is preferable that the light shielding plate 30 is installed within a range of 5 mm or less on all four sides of the rectangular tube with respect to the opening 27 of the polarizing element holding unit 26. Further, the height of the light shielding plate 30 in the Z-axis direction preferably has an interval of at least 5 mm or more with respect to the irradiation surface of the workpiece W when the polarized light irradiation device 1 irradiates the workpiece W.

  The polarized light irradiation apparatus 1 according to the first embodiment has the above configuration, and the operation thereof will be described below. FIG. 3 is an explanatory view showing a light irradiation state in the polarized light irradiation apparatus shown in FIG. When the polarized light irradiation apparatus 1 performs an alignment process on a workpiece W that is an object to be irradiated such as an alignment film of a liquid crystal panel or an alignment film of a viewing angle compensation film, the workpiece W is conveyed by a conveying device (not shown) The light source 5 emits light including ultraviolet rays while conveying the workpiece W in the direction of the arrow Y1 parallel to the Y-axis direction.

  Among the light emitted from the light source 5, a part of the light is directed toward the filter 20 and enters the filter 20 (for example, L <b> 1 in FIG. 3). The filter 20 transmits only the ultraviolet rays without transmitting anything other than the ultraviolet rays, and only the ultraviolet rays are emitted from the surface opposite to the light incident surface.

  The ultraviolet rays emitted from the filter 20 are incident on the polarizing element 25 held by the polarizing element holding unit 26 located on the opposite side of the filter 20 from the side where the light source 5 is located. The polarizing element 25 does not pass most of the incident ultraviolet rays having a polarization axis parallel to the longitudinal direction of the electric conductor constituting the polarizing element 25, and only the ultraviolet rays having a polarization axis orthogonal to the longitudinal direction of the electric conductor. Pass through. Thereby, the polarizing element 25 emits only the ultraviolet rays oscillated in the reference direction from the surface opposite to the surface on which the filter 20 is located. Polarized light composed of ultraviolet rays oscillating in the reference direction and emitted from the polarizing element 25 passes through the opening 27 of the polarizing element holding unit 26 and is disposed on the opposite side of the polarizing element holding unit 26 from the side where the filter 20 is located. The workpiece W is irradiated through the inside of the light shielding plate 30. In the workpiece W, the alignment treatment is performed by the polarized light composed of the ultraviolet rays.

  Further, when the light emitted from the light source 5 passes through the filter 20 and the polarizing element 25 in this way, a part of the polarized light emitted from the polarizing element 25 is directed to the light shielding plate 30 (for example, , L2 in FIG. That is, a part of the polarized light emitted from the polarizing element 25 passes through the opening 27 of the polarizing element holding unit 26 and surrounds the opening 27 of the polarizing element holding unit 26 when viewed in the Z-axis direction. It faces the light shielding plate reflecting surface 31 in the light shielding plate 30 disposed in the surface and contacts the light shielding plate reflecting surface 31. As a result, the polarized light hitting the light shielding plate reflecting surface 31 travels in the direction opposite to the direction in which the polarized light was directed before hitting the light shielding plate reflecting surface 31 in the Y-axis direction. .

  Thus, since the inner surface of the light shielding plate 30 that shields the polarized light is formed as the light shielding plate reflecting surface 31 that reflects the light, the polarized light hitting the light shielding plate reflecting surface 31 is reflected on the light shielding plate reflecting surface. The light is reflected at 31 and travels in the direction opposite to the direction of incidence on the light-reflecting plate reflecting surface 31. That is, the polarized light reflected by the light-shielding plate reflection surface 31 goes in the direction away from the polarization element holding unit 26 while moving toward the light-shielding plate reflection surface 31 facing the light-shielding plate reflection surface 31 that reflects the polarized light. Thereby, the polarized light reflected by the light shielding plate reflecting surface 31 is directed toward the workpiece W and is irradiated onto the workpiece W.

  In addition, some of the light emitted from the light source 5 is directed toward the reflecting surface 11 of the reflecting plate 10, and the light directed toward the reflecting surface 11 is reflected by the reflecting surface 11 and is directed toward the filter 20. Head (for example, L3 in FIG. 3). Thus, the light directed toward the filter 20 is irradiated onto the filter 20 to emit only ultraviolet rays, and the ultraviolet rays emitted from the filter 20 enter the polarizing element 25.

  That is, the reflecting surface 11 of the reflecting plate 10 is located near the polarizing element 25 on the surface opposite to the side where the filter 20 is located in the polarizing element 25, when the light is emitted from the light source 5 and hits the reflecting surface 11. The light is reflected so as to be condensed at the focal point F. For this reason, the ultraviolet rays irradiated from the filter 20 after being reflected by the reflecting surface 11 and emitted from the filter 20 are incident on the polarizing element 25 in front of the focal point F when viewed from the filter 20. The polarizing element 25 on which the ultraviolet rays from the filter 20 are incident emits polarized light composed of ultraviolet rays oscillating in the reference direction. This polarized light is irradiated to the workpiece W through the inside of the light shielding plate 30.

  In addition, a part of the polarized light emitted from the polarizing element 25 after being reflected by the reflecting surface 11 of the reflecting plate 10 and passing through the filter 20 and the polarizing element 25 passes through the focal point F. It goes to the light shielding plate 30 (for example, L4 in FIG. 3). This polarized light is directly incident on the filter 20 from the light source 5, passes through the filter 20 and the polarizing element 25, hits the light shielding plate reflecting surface 31, and is reflected by the light shielding plate reflecting surface 31. Reflected by the surface 31 and directed toward the workpiece W. That is, the polarized light hitting the light shielding plate reflecting surface 31 is shielded by the light shielding plate 30 with respect to the traveling direction before hitting the light shielding plate 30, and reflected by the light shielding plate reflecting surface 31 in the direction of the workpiece W. Thereby, the polarized light reflected by the light shielding plate reflecting surface 31 is irradiated to the workpiece W.

  Since the polarized light irradiation apparatus 1 according to the first embodiment shields part of the polarized light emitted from the polarizing element 25 with the light shielding plate 30, it can irradiate the workpiece W without spreading the polarized light too much. . FIG. 4 is an explanatory diagram of a polarized light irradiation apparatus that does not include a light shielding plate. That is, when irradiating the workpiece W with polarized light using the polarized light irradiation device 100 without the light shielding plate 30, the light emitted from the light source 5 directly passes through the filter 20 and the polarizing element 25. The polarized light emitted from the polarizing element 25 is irradiated onto the workpiece W in the same manner as the polarized light irradiation apparatus 1 according to the first embodiment (for example, m1 in FIG. 4). Comparing the trajectories of both ultraviolet rays depending on the presence or absence of the light shielding plate, in the polarized light irradiation apparatus 1 according to the first embodiment, a part of the polarized light is shielded by the light shielding plate 30, thereby the Y axis direction of the light shielding plate 30. The polarized light is reflected by the light-shielding plate reflecting surface 31 without going in the direction toward which the polarized light was directed before hitting the light-shielding plate 30 than the position at. On the other hand, in the polarized light irradiation device 100 without the light shielding plate 30, the polarized light is not shielded by the light shielding plate 30, and therefore from the position where the light shielding plate 30 in the polarized light irradiation device 1 according to the first embodiment is disposed. Also, it goes toward the outer side of the light shielding plate 30 formed in a rectangular tube shape.

  Similarly, the polarized light emitted from the polarizing element 25 by passing through the filter 20 and the polarizing element 25 after being emitted from the light source 5 toward the reflecting plate 10 and reflected by the reflecting surface 11 is the first embodiment. The workpiece W is irradiated in the same manner as the polarized light irradiation apparatus 1 according to (for example, m2 in FIG. 4). Comparing the orbits of both ultraviolet rays depending on the presence or absence of the light shielding plate, similarly, the polarized light after being reflected by the reflecting surface 11 is not shielded by the light shielding plate 30, so that part of the polarized light is polarized light according to the first embodiment. From the position where the light shielding plate 30 is disposed in the irradiating device 1, the light shielding plate 30 is formed in the direction of the outer side of the light shielding plate 30 formed in a rectangular tube shape.

  That is, in the polarized light irradiation device 100 without the light shielding plate 30, the polarized light emitted from the polarizing element 25 is not shielded by the light shielding plate 30, so that the region where the polarizing element 25 is disposed in the Z-axis direction view, or The workpiece W is easy to be irradiated with light that has spread larger than the region where the opening 27 is formed and whose polarization axis has deteriorated. On the other hand, in the polarized light irradiation device 1 according to the first embodiment, out of the polarized light emitted from the polarizing element 25, the polarized light that hits the light shielding plate 30 from the inside of the light shielding plate 30, that is, the light shielding plate reflection surface 31. Since the light is shielded by the light shielding plate 30, the irradiation area in the Z-axis direction view is difficult to expand. For this reason, it is suppressed that the workpiece | work W is irradiated with the polarized light whose polarization axis characteristics are reduced outside the irradiation range.

  In addition, the inventors tested the irradiation state of the polarized light irradiated by the polarized light irradiation device 1 with and without the light shielding plate 30. FIG. 5 is a chart of test results of the irradiation state of polarized light. In the test, the width of the opening 27 in the Y-axis direction is 50 mm, that is, the polarized light is emitted by the polarized light irradiation devices 1 and 100 in which the opening 27 is open in the range of ± 25 mm in the Y-axis direction from directly below the light source 5. Irradiation was performed, and polarization axis characteristics on the irradiated surface were measured by measuring polarized light at a plurality of measurement points. As measurement points, the polarized light irradiation device 1 (FIG. 3) having the light shielding plate 30 and the polarized light irradiation device 100 (FIG. 4) having no light shielding plate 30 are respectively located immediately below the light source 5 and the light source 5. The polarization axis characteristics were measured at a position ± 20 mm away from directly below, a position ± 30 mm apart, and a position ± 40 mm apart.

  In this test, the polarized light irradiation device 1 having the light shielding plate 30 and the polarized light irradiation device 100 without the light shielding plate 30 can both detect polarized light having a polarization axis of 0.02 ° immediately below the light source 5. It was. Further, at a position of ± 20 mm from directly below the light source 5, both the polarized light irradiation device 1 with the light shielding plate 30 and the polarized light irradiation device 100 without the light shielding plate 30 both have polarized light with a polarization axis of 0.06 °. Could be detected.

  On the other hand, the polarized light irradiation apparatus 100 without the light shielding plate 30 was able to detect the polarized light at the position ± 30 mm directly below the light source 5 and at the position ± 40 mm directly below the light source 5. In the polarized light irradiation device 1 having the plate 30, the polarized light could not be detected. That is, at a position ± 30 mm from directly below the light source 5, the polarized light irradiation device 100 without the light shielding plate 30 can detect polarized light having a polarization axis of 0.15 °, and at a position ± 40 mm from directly below the light source 5, The polarized light irradiation apparatus 100 without the light shielding plate 30 was able to detect polarized light having a polarization axis of 0.30 °. On the other hand, in the polarized light irradiation device 1 having the light shielding plate 30, the polarized light could not be detected at these measurement points. From these, it was confirmed that the polarized light emitted from the opening 27 was not irradiated to the outside of the light shielding plate 30.

  The polarized light irradiation apparatus 1 according to the first embodiment surrounds the opening 27 when viewed in the opening direction of the opening 27 on the exit side of the polarized light in the opening 27 formed in the polarizing element holding unit 26. Since the light shielding plate 30 disposed at is provided, the light polarized toward the outside of the region where the opening 27 is formed in the same direction can be shielded by the light shielding plate 30. Thereby, the polarized light emitted from the polarizing element 25 can be made difficult to spread, and the workpiece W can be prevented from being irradiated with the polarized light having the polarization axis characteristic deteriorated outside the irradiation range.

[Embodiment 2]
The polarized light irradiation device 40 according to the second embodiment has substantially the same configuration as the polarized light irradiation device 1 according to the first embodiment, but a transparent member that shields the space inside the light shielding plate is disposed on the light shielding plate. There is a feature in that. Since other configurations are the same as those of the first embodiment, the description thereof is omitted and the same reference numerals are given.

  FIG. 6 is a cross-sectional view of the polarized light irradiation apparatus according to the second embodiment when viewed in the X-axis direction. Similarly to the polarized light irradiation device 1 according to the first embodiment, the polarized light irradiation device 40 according to the second embodiment includes the reflector 10 that controls the light distribution of the light emitted from the light source 5 and the incident light. It has a filter 20 that emits only ultraviolet rays, a polarizing element 25, and a polarizing element holding unit 26 that holds the polarizing element 25. Further, on the side of the polarizing element holding portion 26 facing the light source 5, a light shielding plate 50 that is formed in a substantially rectangular tube shape and shields polarized light is provided. As in the light shielding plate 30 included in the polarized light irradiation apparatus 1 according to the first embodiment, the light shielding plate 50 has an inner surface formed as a light shielding plate reflecting surface 51 that reflects light.

  Further, in the polarized light irradiation device 40 according to the second embodiment, glass that is a transparent member that closes the space inside the light shielding plate 50 at the end of the light shielding plate 50 opposite to the side where the opening 27 is located. A plate 52 is provided. That is, the light shielding plate 50 is formed so that the longitudinal direction of the square tube is in the Z-axis direction, and the side facing the work W, that is, the end opposite to the end on the polarizing element holding unit 26 side is opened. However, the glass plate 52 is formed so as to close the opening portion of the light shielding plate 50.

  The glass plate 52 is formed of a glass that is a transparent member that transmits light, and is formed in a rectangular plate shape that is substantially the same shape as the rectangular tube that is the shape of the light shielding plate 50 when viewed in the Z-axis direction. The light shielding plate 50 is provided at the end in a direction parallel to the polarizing element 25. Accordingly, the glass plate 52 closes the space inside the light shielding plate 50 and shields the space inside the light shielding plate 50 from the outside of the light shielding plate 50.

  FIG. 7 is a BB arrow view of FIG. FIG. 8 is a view taken along the line CC in FIG. The light shielding plate 50 has air supply / exhaust portions 55 formed at a plurality of locations. The air supply / exhaust unit 55 includes an air supply unit 56 formed on one wall surface among the four wall surfaces constituting the light shielding plate 50, and an exhaust unit 57 formed on a wall surface facing the wall surface. ing. Specifically, among the four wall surfaces of the light shielding plate 50, the air supply portion 56 is provided on one of the two wall surfaces that are located at the end in the X-axis direction and face the X-axis direction. An exhaust portion 57 is provided on the other wall surface.

  The air supply unit 56 is formed in a pipe shape, and is attached so as to communicate with the wall surface of the light shielding plate 50. A hole communicating with the inside of the pipe-shaped air supply unit 56 is formed in a portion of the wall surface of the light-shielding plate 50 where the air supply unit 56 is attached. It communicates with the inner space. A plurality (three in the second embodiment) of air supply units 56 formed in this way are provided on the same wall surface of the light shielding plate 50. An air supply device (not shown) such as external high-pressure air is connected to the air supply unit 56 provided in this way, and the wind sent from the air supply device flows in the air supply unit 56. It has become.

  The exhaust part 57 is provided with one of the four wall surfaces of the light shielding plate 50 and one of the two wall surfaces located at the end in the X-axis direction and facing the X-axis direction. It is provided on the other wall surface facing the wall surface formed. The exhaust part 57 is formed by a hole penetrating the wall surface, whereby the exhaust part 57 communicates the space inside the light shielding plate 50 with the outside. A plurality (three in the second embodiment) of exhaust portions 57 formed in this manner are provided on the same wall surface of the light shielding plate 50, similarly to the air supply portion 56.

  The polarized light irradiation apparatus 40 according to the second embodiment has the above configuration, and the operation thereof will be described below. When the polarized light irradiation device 40 performs an alignment process on a workpiece W such as an alignment film of a liquid crystal panel or an alignment film of a viewing angle compensation film, light including ultraviolet rays is emitted from the light source 5. As a result, only ultraviolet rays are emitted from the filter 20 when passing through the filter 20, and polarized light composed of ultraviolet rays oscillating in the reference direction is emitted when the ultraviolet light polarizing element 25 is emitted. The polarized light emitted from the polarizing element 25 passes through the inside of the light shielding plate 50 as it is or is reflected by the light shielding plate reflecting surface 51, so that the polarizing element holding portion 26 of the light shielding plate 50 on the side where the polarizing element holding portion 26 is located. Head in the direction of the opposite end.

  Since the glass plate 52 is disposed at the end of the light shielding plate 50 opposite to the end of the polarizing element holding unit 26 side, the polarized light directed in this direction enters the glass plate 52. Since the glass plate 52 is made of a transparent member and can transmit light, the polarized light incident on the glass plate 52 passes through the glass plate 52 as it is and is opposite to the surface on which the polarized light is incident. The light is emitted from the side surface. The polarized light transmitted through the glass plate 52 in this way is directed toward the workpiece W and is irradiated onto the workpiece W.

  As described above, when the light source 5 of the polarized light irradiation device 40 is turned on and the orientation process is performed on the workpiece W, the light is cooled inside the light shielding plate 50 by the high-pressure air connected to the air supply unit 56. Wind E is sent to cool the polarizing element 25. Specifically, the air is sent to the air supply unit 56 as the cooling air E by high-pressure air, and the air is sent from the air supply unit 56 to the inside of the light shielding plate 50. Since the exhaust portion 57 is formed on the surface opposite to the surface on which the air supply portion 56 is disposed in the light shielding plate 50, when air is sent from the air supply portion 56 to the inside of the light shielding plate 50, The air inside the light shielding plate 50 is pushed out from the exhaust part 57 in accordance with the sent air, and is exhausted outside the light shielding plate 50.

  When the light source 5 of the polarized light irradiation device 40 is turned on, it emits light and generates heat. The polarized light irradiation device 40 collects the light emitted from the light source 5 in the vicinity of the polarizing element 25. Therefore, the heat generated by the light source 5 at the time of light emission is also easily collected in the polarizing element 25 by radiation. For this reason, when the light source 5 is turned on, the temperature of the polarizing element 25 is likely to rise, and accordingly, the temperature of the air inside the light shielding plate 50 is also likely to rise. By sending air to the inside of the light shielding plate 50 and exhausting the air in the light shielding plate 50 from the exhaust part 57, the air having a higher temperature can be replaced with the air having a lower temperature.

  Thereby, the air inside the light shielding plate 50 whose temperature is low can exchange heat with the polarizing element 25 whose temperature is high, and the temperature of the polarizing element 25 can be lowered. As described above, the air supply / exhaust unit 55 including the air supply unit 56 and the exhaust unit 57 cools the polarizing element 25 by sending air into the light shielding plate 50 and discharging the air inside the light shielding plate 50. The cooling air E that can be flowed is allowed to flow inside the light shielding plate 50, and the temperature of the polarizing element 25 is reduced by dissipating heat to the cooling air E.

  Further, since the inner side of the light shielding plate 50 is closed by the glass plate 52, dust or the like is prevented from entering the inner side of the light shielding plate 50. For this reason, it is difficult for dust or the like to adhere to the polarizing element 25 that emits the polarized light that irradiates the workpiece W, and the polarizing element 25 is difficult to get dirty.

  In the polarized light irradiation device 40 according to the second embodiment, the glass plate 52 is disposed at the end of the light shielding plate 50 opposite to the side where the opening 27 of the polarizing element holding unit 26 is located. It is possible to prevent dirt from adhering to the polarizing element 25. Thereby, it can suppress that the extinction ratio in the polarizing element 25 falls. As a result, the photo-alignment performance can be maintained for a long time.

  Further, the light shielding plate 50 is provided with air supply / exhaust portions 55 at a plurality of locations, and the cooling air E is caused to flow inside the light shielding plate 50 by the air supply / exhaust portion 55, so that the polarizing element 25 is cooled by the cooling air E. be able to. As a result, it is possible to suppress the deterioration of the polarizing element 25 due to the temperature of the polarizing element 25 becoming high, and it is possible to more reliably suppress the decrease in the extinction ratio.

[Modification]
In the polarized light irradiation apparatus 40 according to the second embodiment described above, the air supply / exhaust unit 55 is formed on the wall surface of the light shielding plate 50 facing the X-axis direction. It may be formed in the position. FIG. 9 is a modified example of the polarized light irradiation apparatus according to the second embodiment, and is an explanatory diagram when the light shielding plate is viewed in the Y-axis direction. FIG. 10 is a view taken along the line DD in FIG. For example, as shown in FIGS. 9 and 10, the air supply / exhaust unit 55 may be provided on a wall surface facing the Y-axis direction among the four wall surfaces of the light shielding plate 50. Specifically, the air supply / exhaust portion 55 is provided with an air supply portion 56 on one wall surface of two wall surfaces located at the end in the Y axis direction and facing the Y axis direction, and the other wall surface. It may be provided by forming the exhaust part 57.

  In this case, for example, when a plurality of polarizing elements 25 are arranged side by side in the X-axis direction, a plurality of air supply parts 56 and exhaust parts 57 are formed corresponding to the position of the polarizing element 25 in the X-axis direction. Preferably it is done. In this way, by providing the air supply unit 56 and the exhaust unit 57 corresponding to the polarizing element 25, the cooling air E that flows inside the light shielding plate 50 by the air supply unit 56 and the exhaust unit 57 is converted into the polarizing element. It can be made to flow every 25. Thereby, the polarizing element 25 can be cooled more reliably, and the deterioration of the polarizing element 25 due to the increase in temperature can be more reliably suppressed.

  Moreover, in the polarized light irradiation device 40 according to the second embodiment described above, the example in which the blower is connected to the air supply unit 56 is described, but the present invention is not limited thereto. For example, an air blower may be connected to the pipe-shaped exhaust part 57, and air may be extracted from the exhaust part 57 using the air blower. Moreover, both the air supply part 56 and the exhaust part 57 are pipe-shaped, and the cooling air E may circulate by an air circulation device.

  Moreover, in the polarized light irradiation apparatuses 1 and 40 described above, the reflecting plate 10 is made of glass and the reflecting surface 11 is formed of a multilayer film, but the reflecting plate 10 may be formed of other materials. Good. The reflector 10 may be entirely made of a metal such as aluminum, for example. Moreover, the reflective surface 11 does not need to be strictly formed in an elliptical shape.

  In the polarized light irradiation apparatuses 1 and 40 described above, the light source 5 is described using a so-called tube-type discharge lamp, but the light source 5 may be other than the discharge lamp. For example, the light source 5 emits light including ultraviolet rays, such as LED chips, laser diodes, organic EL, and other small lamps that can emit ultraviolet rays having a wavelength of 200 nm to 400 nm. Other than the discharge lamp may be used.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof as well as included in the scope and gist of the invention.

DESCRIPTION OF SYMBOLS 1, 40, 100 Polarized light irradiation apparatus 5 Light source 10 Reflector 11 Reflecting surface 12 Gap part 20 Filter 21 Filter frame 25 Polarizing element 26 Polarizing element holding part 27 Opening part 30, 50 Light shielding plate 31, 51 Light shielding board reflecting surface 52 Glass Board (transparent member)
55 Air supply / exhaust part 56 Air supply part 57 Exhaust part

Claims (3)

A light source that emits light;
A filter that is irradiated with the light emitted from the light source and emits ultraviolet rays;
A polarizing element disposed on a side opposite to the light source side of the filter and configured to enter the ultraviolet light and emit polarized light;
A polarizing element holding unit that holds the polarizing element and has an opening that transmits the polarized light emitted from the polarizing element;
A light-shielding plate disposed on the side of the polarizing element holding portion facing the light source and disposed around the opening;
A polarized light irradiation apparatus comprising:   The polarized light irradiation apparatus according to claim 1, wherein a transparent member that closes a space inside the light shielding plate is disposed at an end of the light shielding plate opposite to the side where the opening is located.   The polarized light irradiation apparatus according to claim 2, wherein the light shielding plate has air supply / exhaust portions formed at a plurality of locations.

Images