Polarization light irradiation unit, polarization light irradiation device, and polarization light irradiation method

Abstract

To provide a polarization light irradiation unit which enables irradiation of polarization light in which variation in polarization axes is small, to provide a polarization light irradiation device, and to provide a polarization light irradiation method.SOLUTION: A polarization light irradiation unit includes a light source, a polarization element, and a light shielding plate. The light source has a rod-like shape. The polarization element polarizes the light emitted from the light source, and is arranged between the light source and an object. The light shielding plate has a flat plate shape, has an opening, and is arranged between the light source and the object. In the case where the longer direction of the light source is defined as the left-to-right direction, and the direction orthogonal to the longer direction and in parallel with the light shielding plate is defined as the vertical direction, the opening has an upper side and a lower side which are in parallel in the left-to-right direction respectively, and in at least part of the left-most portion of the opening and in at least part of the right-most portion of the opening, the position in the vertical direction is the same on the position which is neither the position of the upper side nor the position of the lower side, and at least one of the left end of the upper end and the left end of the lower side or the right end of the upper side and the right end of the lower side is not connected by a linear one side.SELECTED DRAWING: Figure 3A

Description

[Technical Field]

[0001] The present invention relates to a polarized light irradiation unit, a polarized light irradiation device, and a polarized light irradiation method. [Background technology]

[0002] Patent Document 1 describes a polarized light irradiation device for generating alignment in a photo-alignment film. In this polarized light irradiation device, the entire light irradiation unit rotates around an axis perpendicular to the photo-alignment film. This makes it possible to irradiate polarized light with little variation in the polarization axis. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-133498 Summary of the Invention [Problem to be solved by the invention]

[0004] Thus, there is a demand for a technology that enables irradiation with polarized light with little variation in the polarization axis.

[0005] In view of the above circumstances, an object of the present invention is to provide a polarized light irradiation unit, a polarized light irradiation device, and a polarized light irradiation method that are capable of irradiating polarized light with little variation in the polarization axis. [Means for solving the problem]

[0006] In order to achieve the above object, a polarized light irradiation unit according to an embodiment of the present technology includes a light source, a polarizing element, and a light blocking plate. The light source has a rod shape. The polarizing element polarizes the light emitted from the light source and is disposed between the light source and the object. The light blocking plate has a flat plate shape, has an opening, and is disposed between the light source and the object. When the longitudinal direction of the light source is the left-right direction, and the direction perpendicular to the longitudinal direction and parallel to the light blocking plate is the up-down direction, the opening has an upper side and a lower side that are parallel to the left-right direction, at least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are located at the same position in the up-down direction, which is neither the position of the upper side nor the position of the lower side; At least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side is not connected by a straight line.

[0007] In this polarized light irradiation unit, light emitted from a light source is polarized and partially blocked by a light-blocking plate having an opening. The opening has upper and lower sides parallel to the left-right direction, and at least a portion of the leftmost portion and at least a portion of the rightmost portion are located at the same position in the up-down direction that is neither the upper nor the lower side, and at least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side, is not connected by a straight line. This makes it possible to irradiate polarized light with little variation in the polarization axis.

[0008] At least one of the leftmost portion of the opening or the rightmost portion of the opening may consist of only one point.

[0009] At least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening may be positioned at the same position in the up-down direction as the light source.

[0010] The opening may have at least one of a left tapered portion whose diameter in the vertical direction decreases toward the left side and a right tapered portion whose diameter in the vertical direction decreases toward the right side.

[0011] The opening may have a hexagonal shape that is line-symmetrical with respect to the vertical axis, and two sides of the hexagon may be the upper side and the lower side.

[0012] The opening may be symmetrical about the left-right axis.

[0013] The opening may not be symmetrical about the left-right axis, and neither of the two sides adjacent to the bottom side may be perpendicular to the bottom side.

[0014] The opening may not be symmetrical about the left-right axis, and two sides adjacent to the bottom side may both be perpendicular to the bottom side.

[0015] The object may have a flat plate shape, and the light blocking plate may be disposed parallel to the object.

[0016] The object and the polarizing element may have a flat plate shape, and the polarizing element may be disposed parallel to the object.

[0017] The light blocking plate may be disposed between the polarizing element and the object.

[0018] The one or more light-blocking plates are a plurality of light-blocking plates arranged parallel to each other, and in each of the plurality of light-blocking plates, at least a portion of the opening may overlap with at least a portion of the opening of at least one other light-blocking plate at different positions in the vertical direction and in the horizontal direction.

[0019] The polarized light irradiation unit may further include a movement mechanism capable of moving at least one of the plurality of light blocking plates in the left-right direction.

[0020] The polarizer may be a wire grid polarizer.

[0021] A polarized light irradiation device according to an aspect of the present technology includes the polarized light irradiation unit and a conveying section that conveys the object along the up-down direction.

[0022] A polarized light irradiation method according to an aspect of the present technology includes polarizing light emitted from a rod-shaped light source using a polarizing element disposed between the light source and an object; a flat plate-shaped light source having an opening, and one or more light blocking plates arranged between the light source and the object to block a portion of the light; A polarized light irradiation method for irradiating the object with polarized light, When the longitudinal direction of the light source is the left-right direction, and the direction perpendicular to the longitudinal direction and parallel to the light blocking plate is the up-down direction, the opening has an upper side and a lower side that are parallel to the left-right direction, at least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are located at the same position in the up-down direction, which is neither the position of the upper side nor the position of the lower side; At least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side is not connected by a straight line. [Effects of the Invention]

[0023] According to the present invention, it is possible to irradiate polarized light with little variation in the polarization axis. Note that the effects described here are not necessarily limited to those described herein, and any of the effects described in this disclosure may be achieved. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a schematic diagram illustrating a configuration example of a polarized light irradiation unit according to an embodiment of the present technology. [Figure 2] FIG. 2 is a cross-sectional view of a polarized light irradiation unit. [Figure 3A] FIG. 2 is a schematic diagram showing an example of the configuration of an aperture. [Figure 3B] FIG. 2 is a schematic diagram showing an example of the configuration of an aperture. [Figure 4A] 10 is a graph showing variations in polarization axes. [Figure 4B] 10 is a graph showing variations in polarization axes. [Figure 5] FIG. 10 is a schematic diagram showing an aperture of a comparative example. [Figure 6A] FIG. 10 is a schematic diagram showing positions on an irradiation surface corresponding to openings of an aperture of a comparative example. [Figure 6B] 10 is a schematic diagram showing a position on an irradiation surface corresponding to an opening of an aperture of the present technology. [Figure 7A] 10 is a diagram showing the illuminance distribution on the irradiation surface when the aperture 9 of the present technology is used. [Figure 7B] 10 is a diagram showing the illuminance distribution on the irradiation surface when an aperture 21 of a comparative example is used. FIG. [Figure 8] 1 is a graph showing the amount of exposure. [Figure 9A] 10A to 10C are schematic diagrams showing variations of openings. [Figure 9B] 10A to 10C are schematic diagrams showing variations of openings. [Figure 10] FIG. 10 is a schematic diagram showing an example of a configuration in which apertures are connected. [Figure 11A] FIG. 10 is a schematic diagram showing the irradiation width when two apertures of the comparative example are connected together. [Figure 11B] 1 is a schematic diagram showing an irradiation width when two apertures according to the present technology are connected together. FIG. [Figure 12A] 10 is a graph showing the uniformity of the exposure amount. [Figure 12B] 10 is a graph showing the uniformity of the exposure amount. [Figure 12C] 10 is a graph showing the uniformity of the exposure amount. [Figure 12D] 10 is a graph showing the uniformity of the exposure amount. [Figure 12E] 10 is a graph showing the uniformity of the exposure amount. [Figure 12F] 10 is a graph showing the uniformity of the exposure amount. [Figure 13] 10 is a graph showing the relationship between overlap width and uniformity. [Figure 14] 10A and 10B are schematic diagrams showing the operation of a moving mechanism. DETAILED DESCRIPTION OF THE INVENTION

[0025] Hereinafter, embodiments of the present technology will be described with reference to the drawings.

[0026] First Embodiment [Polarized light irradiation unit] FIG. 1 is a schematic diagram showing a configuration example of a polarized light irradiation unit 1 according to an embodiment of the present technology. FIG. 2 is a cross-sectional view of the polarized light irradiation unit 1. As shown in FIG. FIG. 2 shows a cross-sectional view of the polarized light irradiation unit 1 taken along the YZ plane at the center in the X direction.

[0027] The polarized light irradiation unit 1 is configured to irradiate polarized light onto a workpiece W being transported in a predetermined direction. As shown in FIG. 1, in this embodiment, a long, strip-shaped workpiece W is pulled out from a feed roller 2 and taken up by a take-up roller 3. The polarized light irradiation unit 1 irradiates polarized light onto the workpiece W being transported from the feed roller 2 towards the take-up roller 3. As indicated by the arrow T in the figure, the transport direction of the workpiece W is from the feed roller 2 towards the take-up roller 3.

[0028] For example, a photo-alignment film is formed on the workpiece W in advance, and then polarized light of a predetermined wavelength, such as ultraviolet light, is irradiated by the polarized light irradiation unit 1. This technology can be used for such an alignment process. Of course, the application of this technology is not limited to alignment processes in which polarized light is irradiated onto a photo-alignment film. Furthermore, the polarized light irradiation unit 1 may be capable of emitting light of any wavelength, not limited to ultraviolet light.

[0029] For convenience, the following XYZ coordinates are defined for the drawing. X direction: Width direction of the strip-shaped workpiece W Y direction: Workpiece W transport direction Z direction: Normal direction of workpiece W (vertical direction) The positive side of the X direction is the right side when viewed from the positive side of the Z axis. The negative side of the Y direction is the direction T in which the workpiece W moves. The positive side of the Z direction is the vertically upward direction. Of course, the application of this technology is not limited to the direction in which the polarized light irradiation unit 1 is used or the direction in which the workpiece W is transported.

[0030] The workpiece W has a flat plate shape. In this example, the workpiece W has a strip shape, but this shape is also included in the flat plate shape. It is not limited to this, and the workpiece W may have other flat plate shapes such as a flat rectangular shape or a circular shape. In addition, the present technology also includes a case where a thin workpiece W is placed on a flat plate-shaped table, and the table and workpiece W as a whole form a flat plate shape. Furthermore, the workpiece W may have a shape other than a flat plate shape.

[0031] For example, a resin film is placed as the workpiece W. The type of workpiece W is not limited, and the present technology can be applied to any irradiation target object. The workpiece W corresponds to an embodiment of the target object according to the present technology.

[0032] The polarized light irradiation unit 1 has a housing 5, a light source 6, a focusing mirror 7, a polarizing element 8, an aperture 9, and a control unit 13. Note that the polarizing element 8 is not shown in FIG. 1. The housing 5 has a rectangular parallelepiped shape and is made of, for example, a rigid material. The housing 5 is fixed so as to be positioned vertically above the workpiece W, for example, by two fixing members 10a and 10b shown in FIG. 1. Note that the housing 5 is illustrated by a dashed line in FIG. 1. The specific configuration of the housing 5, such as its shape, material, and arrangement, is not limited, and any configuration may be used within the scope that makes it possible to realize the present technology. Furthermore, any means for fixing the housing 5 may also be used.

[0033] Light source 6 is a rod-shaped light source such as a rod-shaped lamp, and emits diffused light. Light source 6 is arranged to extend in the X direction. Collecting mirror 7 has a shape formed by bending a rectangular flat plate into a U shape. Collecting mirror 7 is arranged to surround light source 6, with the lower part of the U facing the positive side of the Z axis, and to extend in the X direction as a whole. Light source 6 and collecting mirror 7 are fixed inside housing 5 by means not shown (for example, by fixing members not shown provided inside housing 5).

[0034] Polarizing element 8 is a wire-grid polarizing element. A wire-grid polarizing element is a polarizing element formed by arranging metal wires, such as aluminum wires, in parallel on quartz glass. Polarizing element 8 transmits and polarizes only the component of the light emitted from light source 6 that vibrates in one direction. In this embodiment, polarizing element 8 polarizes the light emitted from light source 6 into linearly polarized light. Polarizing element 8 may be of a type other than a wire-grid polarizing element.

[0035] The polarizing element 8 has a rectangular flat plate shape and is arranged parallel to the XY plane. In other words, the polarizing element 8 is arranged parallel to the workpiece W. As shown in FIG. 2, the polarizing element 8 is fixed to a fixing member 11 provided inside the housing 5, for example. The polarizing element 8 may have a shape other than a flat plate shape, and the specific shape is not limited.

[0036] In this embodiment, of the diffused light emitted from the light source 6, light traveling downward in FIG. 2 reaches the polarizing element 8 as is, but light traveling upward is reflected downward by the collecting mirror 7 before reaching the polarizing element 8. This light is then polarized by the polarizing element 8 and emitted vertically downward.

[0037] The aperture 9 has a rectangular flat plate shape. In this embodiment, the aperture 9 is configured integrally with the housing 5 so as to be the lower surface of the housing 5. In other words, it can be said that the aperture 9 is arranged parallel to the XY plane and is arranged parallel to the workpiece W. However, this is not limiting, and the aperture 9 may be configured separately from the housing 5. Furthermore, the aperture 9 may have a flat plate shape other than a rectangle.

[0038] Aperture 9 has an opening 12 of a predetermined shape. In FIG. 1, opening 12 is indicated by a dashed line. Aperture 9 is configured so that the polarized light emitted from polarizing element 8 can pass through opening 12, and the polarized light can be blocked in areas other than opening 12. The polarized light that passes through opening 12 reaches workpiece W.

[0039] The control unit 13 controls the operation of each mechanism of the polarized light irradiation unit 1. For example, the control unit 13 controls the timing and intensity of light emission from the light source 6. The conveying speed of the workpiece W may also be controlled by controlling the rotation of the delivery roller 2 and the take-up roller 3. Any other control of mechanisms may also be performed.

[0040] A PLD (Programmable Logic Device) such as an FPGA (Field Programmable Gate Array) or other devices such as an ASIC (Application Specific Integrated Circuit) may be used as the control unit 13. Although the control unit 13 is illustrated schematically as a functional block in Fig. 1, the position where the control unit 13 is configured may be designed arbitrarily.

[0041] Additionally, the specific configuration of the polarized light irradiation unit 1 is not limited. The aperture 9 corresponds to an embodiment of the light blocking plate according to the present technology. The delivery roller 2 and the take-up roller 3 correspond to an embodiment of a conveying section according to the present technology. The polarized light irradiation unit 1, the delivery roller 2, and the take-up roller 3 correspond to an embodiment of a polarized light irradiation device according to the present technology.

[0042] Aperture Opening 3A and 3B are schematic diagrams showing examples of the configuration of the aperture 9. FIG. FIG. 3A shows the aperture 9 as viewed from the positive side of the Z axis. The light source 6, which is located on the front side of the aperture 9 (positive side of the Z axis), is indicated by a dashed line. The longitudinal direction of the light source 6 is the X direction (left-right direction on the paper). Furthermore, if we consider a direction perpendicular to the longitudinal direction of the light source 6 and parallel to the aperture 9, this is the Y direction (up-down direction on the paper) because it is perpendicular to the X direction and parallel to the XY plane. Hereinafter, the left-right direction and the up-down direction on the paper of FIG. 3A may be simply referred to as the left-right direction and the up-down direction.

[0043] Opening 12 has a hexagonal shape that is long in the left-right direction as a whole. The shape of opening 12 can also be said to be pencil-shaped. Hereinafter, the sides of the hexagon will be referred to clockwise as sides 15a, 15b, ..., 15f. Furthermore, the vertex formed by sides 15a and 15b will be referred to as vertex 16a, the vertex formed by sides 15b and 15c will be referred to as vertex 16b, ..., and the vertex formed by sides 15f and 15a will be referred to as vertex 16f.

[0044] Side 15a is the upper side of the hexagon and is parallel to the left-right direction. Side 15d is the lower side of the hexagon and is parallel to the left-right direction. In this example, sides 15a and 15d have the same length. Sides 15c and 15f extend diagonally from the upper right to the lower left. Sides 15b and 15e extend diagonally from the lower right to the upper left. The side 15a corresponds to an embodiment of the upper side according to the present technology. The side 15d corresponds to an embodiment of the lower side according to the present technology.

[0045] In this embodiment, at least a part of the leftmost portion and at least a part of the rightmost portion of opening 12 are positioned in the same vertical position that is neither side 15a nor side 15d.

[0046] In this example, vertex 16e is the leftmost part of opening 12. In this way, if there is a vertex on the left side of opening 12, the leftmost part is only that one point of the vertex. On the other hand, for example, if opening 12 has a left side parallel to the Y direction, the entire left side is the leftmost part.

[0047] Furthermore, at least a part of the leftmost part is also vertex 16e. Thus, if the leftmost part is only one point, part of the leftmost part can only be that one point, but if the leftmost part is an entire side, part of the leftmost part is a line segment or point that is part of that side.

[0048] Similarly, the rightmost portion and at least a portion of the rightmost portion both correspond to vertex 16b. As shown in Fig. 3A, vertices 16e and 16b are both located at the center of opening 12 in the vertical direction and are the same. Furthermore, the center of opening 12 is not located at the position of either side 15a or side 15d. Therefore, vertices 16e and 16b are located at the same position in the vertical direction and are not located at the position of either side 15a or side 15d.

[0049] On the other hand, for example, if vertex 16e is located above the center of opening 12 and vertex 16b is located below the center of opening 12, then their positions in the up-down direction are not the same. Also, if vertices 16e and 16b are both located on side 15a, then although their positions in the up-down direction are the same, they are not the same because they are located on neither side 15a nor side 15d.

[0050] Furthermore, at least a portion of the leftmost portion of the opening 12 and at least a portion of the rightmost portion thereof are located at the same vertical position as the light source 6. As shown in FIG. 3A, the vertices 16e and 16b are located vertically below the light source 6 (toward the back of the page). Therefore, the vertices 16e and 16b are located at the same position as the light source 6. In this example, the light source 6 has a certain width in the vertical direction. In such a case, the positions of the vertices 16e and 16b may be moved up and down within the range of the width of the light source 6.

[0051] Note that the scope of the present technology also includes a case where the vertical positions of at least a part of the leftmost portion and at least a part of the rightmost portion of opening 12 are the same at a position other than the position of light source 6. For example, the positions of vertices 16e and 16b may be the same at a position above light source 6 (excluding the position of side 15a) or below light source 6 (excluding the position of side 15g).

[0052] Furthermore, at least one of the left end of side 15a and the left end of side 15d, or the right end of side 15a and the right end of side 15d, is not connected by a single straight line. In this example, the left end of side 15a (vertex 16f) and the left end of side 15d (vertex 16d) are connected by two sides 15f and 15e, and sides 15f and 15e are not a straight line as a whole. Therefore, the left end of side 15a and the left end of side 15d are not connected by a single straight line.

[0053] Similarly, the right end of side 15a and the right end of side 15d are also connected by two sides 15b and 15c, and therefore are not connected by a single straight line. On the other hand, if vertices 16f and 16d are connected by a single straight line extending vertically or diagonally, the left ends of sides 15a and 15d are connected by a single straight line.

[0054] In this example, the left ends of sides 15a and 15d and the right ends of sides 15a and 15d are not connected by a single straight line. However, the present invention is not limited to this, and a configuration may be adopted in which either the left ends or the right ends are connected by a single straight line, and the other ends are not connected by a single straight line.

[0055] The opening 12 also has at least one of a left tapered portion 17a whose diameter in the vertical direction decreases toward the left side and a right tapered portion 17b whose diameter in the vertical direction decreases toward the right side.

[0056] In FIG. 3B, the left tapered portion 17a and the right tapered portion 17b are indicated by diagonal lines. In this example, opening 12 has both a left tapered portion 17a and a right tapered portion 17b. Left tapered portion 17a has a triangular shape consisting of vertices 16d, 16e, and 16f. Right tapered portion 17b has a triangular shape consisting of vertices 16a, 16b, and 16c.

[0057] Because the left tapered portion 17a is a triangle with vertex 16e facing leftward, its vertical diameter (width in the Y direction) decreases toward the left. Similarly, the right tapered portion 17b has a vertical diameter that decreases toward the right. In other words, the opening diameter of the opening 12 decreases toward the end.

[0058] For example, even if the portion corresponding to side 15f is curved, the diameter of left tapered portion 17a in the up-down direction may become smaller toward the left side, and such a configuration may also be included in the scope of the present technology. Furthermore, opening 12 may be configured to have only either left tapered portion 17a or right tapered portion 17b.

[0059] The opening 12 has a hexagonal shape that is line-symmetrical with respect to an axis in the up-down direction. In Fig. 3B, the axis of symmetry 18y is indicated by a dashed line. The axis of symmetry 18y is located at the center of the opening 12 in the left-right direction. The opening 12 is line-symmetrical with respect to the axis of symmetry 18y. In other words, when the opening 12 is folded in half along the axis of symmetry 18y, the left and right sides of the opening 12 overlap and match each other. The symmetry axis 18y corresponds to an embodiment of an axis in the up-down direction according to the present technology.

[0060] In this embodiment, opening 12 has a hexagonal shape that is line-symmetrical with respect to an axis in the left-right direction. Symmetry axis 18x is indicated by a dashed line in Fig. 3B. Symmetry axis 18x is located at the center of opening 12 in the up-down direction, and when opening 12 is folded in half along symmetry axis 18x, the upper and lower sides of opening 12 overlap and coincide with each other. The axis of symmetry 18x corresponds to an embodiment of an axis in the left-right direction according to the present technology.

[0061] As described above, in the polarized light irradiation unit 1 according to this embodiment, light emitted from the light source 6 is polarized and a portion of the polarized light is blocked by the aperture 9 having the opening 12. The opening 12 has sides 15a and 15d parallel to the left-right direction, and at least a portion of the leftmost portion and at least a portion of the rightmost portion are located at the same position in the up-down direction that is not on either side 15a or 15d, and at least one of the left end of side 15a and the left end of side 15d, or the right end of side 15a and the right end of side 15d, is not connected by a single straight line. This makes it possible to irradiate polarized light with little variation in the polarization axis.

[0062] The technology of aligning a workpiece, such as the alignment film of a liquid crystal panel, by irradiating it with polarized light of a specific wavelength is generally called photo-alignment. In photo-alignment, a polarized light irradiation unit combining a rod-shaped lamp and a polarizing element is used to irradiate polarized light onto a long, strip-shaped alignment film. The light emitted from the rod-shaped lamp is polarized by the polarizing element and irradiated onto the alignment film, thereby achieving photo-alignment processing.

[0063] When a polarizing element is inserted into an electromagnetic wave, the polarized component parallel to the longitudinal direction of the grid is reflected, while the orthogonal polarized component passes through. The orientation direction of the alignment film depends on the direction of the polarization axis of the polarized light (hereinafter sometimes referred to as the polarization direction) irradiated onto the alignment film. Therefore, for example, if it is necessary to align the entire alignment film in the same direction, it is necessary to irradiate the entire alignment film with polarized light having the same polarization direction.

[0064] However, the polarization direction of polarized light exiting a polarizing element also depends on the angle of incidence of the light before polarization. For example, light incident on a polarizing element directly from above will be polarized at a 30-degree angle, but light incident on the polarizing element at an angle may be polarized at a 29-degree or 31-degree angle.

[0065] Because the light source (rod-shaped lamp) emits diffused light, light may enter the polarizing element from an oblique direction. In the following explanation, the longitudinal direction of the light source is referred to as the left-right direction, and the vertical direction as the up-down direction. Light directed from directly above to directly below enters the center of the polarizing element in the left-right direction. Light also enters from the upper left diagonally downward, but light also enters from the upper right diagonally downward to the left diagonally, so the average angle of incidence is close to 0 degrees. Therefore, there is little variation in the polarization axis of the polarized light emitted overall.

[0066] On the other hand, at the right end of the polarizing element, light is incident from directly above toward directly below, and light is also incident from diagonally above left toward diagonally below right, but light is not incident from diagonally above right toward diagonally below left. In other words, a bias occurs in the angle of incidence, and the variation in the polarization axis also increases. Similarly, the variation in the polarization axis also increases at the left end of the polarizing element. In other words, the variation in the polarization axis becomes noticeable near the left and right ends of the polarizing element.

[0067] This causes a problem in that polarized light with a shifted (varied) polarization axis is irradiated onto the edge of the irradiation area. 4A and 4B are graphs showing the variation in polarization axis. FIG. 4A shows the variation in the polarization axis of polarized light irradiated at each point on the irradiation surface. The horizontal and vertical axes represent positions on the irradiation surface, with the center of the vertical axis representing the position of the light source. That is, the light source is positioned extending left and right along the zero axis of the vertical axis. In this example, the polarization angle of the polarizing element is set to 0 degrees (parallel to the longitudinal direction of the rod-shaped lamp), and no aperture is provided. The variation in the polarization axis is illustrated by contour lines in 0.4-degree increments. The variation is also schematically illustrated by the inclination of the arrows.

[0068] In Figure 4B, the horizontal axis represents the position on the horizontal axis in Figure 4A, and the vertical axis represents the variation value. The positions on the vertical axis in Figure 4A correspond to the line types in Figure 4B. For example, the "60 mm" line represents the variation value when focusing only on the 60 mm axis on the vertical axis in Figure 4A.

[0069] 4A, the area indicated by the thick-line frame and grid is the area where the variation is between -0.2 degrees and 0.2 degrees. Therefore, this area is irradiated with polarized light with little variation, and it can be said that the alignment process is generally not affected.

[0070] On the other hand, the variation increases toward the corners of the irradiation surface, ranging from 2.6 to 3.0 degrees at the top left and bottom right, and from -3.0 to -2.6 degrees at the top right and bottom left. Therefore, polarized light with large variations is irradiated onto the corners of the irradiation surface, which causes problems with the alignment process.

[0071] The variation increases as you approach the left or right edge of the irradiation surface, but directly below the lamp (the vertical axis 0 in Figure 4A, the 0 line in Figure 4B), the variation is small even at the left or right edge. In this way, the area with small variation is roughly hexagonal.

[0072] FIG. 5 is a schematic diagram showing an aperture 21 of a comparative example. To solve the problem of polarized light with large variations in the polarization axis being irradiated onto the four corners, etc., one possible measure is to block the polarized light at the corners where the variations are large by using aperture 21 with a rectangular opening. Figure 5 shows aperture 21 of this comparative example. Aperture 21 has rectangular opening 22, and the center position of opening 22 in the vertical direction is the same as the position of rod-shaped light source 23.

[0073] Fig. 6A is a schematic diagram showing positions on the irradiation surface corresponding to the opening of aperture 21 of the comparative example. Similar to Fig. 4A, Fig. 6A also shows, using contour lines, the variation in the polarization axis at each point on the irradiation surface when no aperture is provided. In addition, a shaded rectangle indicates the region on the irradiation surface corresponding to opening 22 of aperture 21. In this example, polarized light located outside the rectangle is blocked by aperture 21, so polarized light with large variations does not reach the edges such as the four corners, and only polarized light with small variations in the central portion reaches the irradiation surface.

[0074] This solves the problem of variations in the polarization axis, but on the other hand, since the area irradiated with polarized light is limited by the aperture 21, another problem arises in that the irradiated area becomes smaller accordingly.

[0075] FIG. 6B is a schematic diagram showing a position on the irradiation surface corresponding to the opening of aperture 9 of the present technology. In the present technology, aperture 12 has a pencil-like (hexagonal) shape, making it possible to widen the irradiation area by an amount corresponding to tapered portions 17a and 17b in FIG. 3B compared to the comparative example. The areas on the irradiation surface corresponding to tapered portions 17a and 17b originally have little variation in the polarized light irradiated, so no problem occurs even if they are not shielded from light. However, in aperture 21 of the comparative example, this area is shielded from light, which can be said to waste the irradiation area that could otherwise be used.

[0076] In this technology, it is possible to secure a larger irradiation area by expanding the shape of the opening 12 into a pencil shape so as not to block light from the relevant area. This allows a larger irradiation area to be secured with an aperture of the same size, which also makes it possible to miniaturize the device.

[0077] 6A and 6B show the irradiation surface and the shape of the opening as corresponding to each other, but because polarized light is diffused light, strictly speaking, the polarized light is not irradiated onto the same area as the shape of the opening. However, by bringing aperture 9 closer to the irradiation surface, the degree of diffusion of polarized light from the time it passes through opening 12 until it reaches the irradiation surface is reduced, making it possible to bring the irradiation area closer to the shape of opening 12.

[0078] FIG. 7A is a diagram showing the illuminance distribution on the irradiation surface when the aperture 9 of the present technology is used. FIG. 7B is a diagram showing the illuminance distribution on the irradiation surface when aperture 21 of the comparative example is used. 7A and 7B, the illuminance on the illuminated surface is expressed by color intensity. In both cases, the illuminance is high directly below the light source, but it can be seen that the area of ​​high illuminance is wider in the left-right direction for aperture 9 of the present technology in Fig. 7A compared to aperture 21 of the comparative example in Fig. 7B.

[0079] FIG. 8 is a graph showing the exposure amount. The horizontal axis represents the left-right position of the irradiation surface, and the vertical axis represents the amount of exposure. For example, at the position of "200 mm" on the horizontal axis, the total amount of energy that a point receives from irradiation when the workpiece W is transported at a constant speed at an arbitrary point that is "200 mm" in the left-right direction of the irradiation surface is shown.

[0080] The exposure amount for aperture 9 of the present technology is shown by a solid line, and the exposure amount for aperture 21 of the comparative example is shown by a dashed line. It can be seen that the exposure amount at the center in the left-right direction is roughly the same, but there is a large difference in the exposure amount at the left and right ends. As shown in Figures 7A and 8, aperture 9 of the present technology can ensure a wider irradiation area in the left-right direction than aperture 21 of the comparative example.

[0081] Furthermore, in the present technology, at least one of the leftmost portion and the rightmost portion of the opening 12 consists of only one point, which makes it possible to ensure the widest possible irradiation area.

[0082] Furthermore, at least a part of the leftmost portion of opening 12 and at least a part of the rightmost portion thereof are positioned in the vertical direction at the same position as light source 6. This makes the width of opening 12 in the horizontal direction widest directly below light source 6, making it possible to ensure greater illuminance.

[0083] Furthermore, the opening 12 has at least one of a left tapered portion 17a and a right tapered portion 17b, which makes it possible to ensure an even wider irradiation area.

[0084] The opening 12 has a hexagonal shape that is line-symmetrical about an axis in the vertical direction, and the two sides of the hexagon are the top and bottom sides. Furthermore, the opening 12 is line-symmetrical about an axis in the horizontal direction. This makes it possible to ensure an even wider irradiation area.

[0085] Furthermore, the workpiece W has a flat plate shape, and the aperture 9 is disposed parallel to the workpiece W. Furthermore, the polarizing element 8 has a flat plate shape, and is disposed parallel to the workpiece W. These make it possible to perform irradiation with high precision.

[0086] Furthermore, a wire grid polarizer is used as the polarizer 8. This allows for accurate polarization.

[0087] <Other embodiments> The present technology is not limited to the above-described embodiment, and various other embodiments can be realized. In the following description, the description of the same configurations and functions as those of the polarized light irradiation unit 1 described in the above embodiment will be omitted or simplified.

[0088] [Opening Variations] FIG. 9A is a schematic diagram showing variations of the opening 12. As shown in FIG. In this example, opening 12 is not line-symmetrical with respect to an axis in the left-right direction. The length of side 15a is different from the length of side 15d. Furthermore, sides 15b and 15c, and sides 15f and 15e are not line-symmetrical with respect to axis of symmetry 18x. Therefore, opening 12 as a whole is not line-symmetrical with respect to axis of symmetry 18x. In other words, when opening 12 is folded in half along axis of symmetry 18x, the upper and lower sides of opening 12 do not overlap so as to coincide with each other. On the other hand, opening 12 is line-symmetrical with respect to an axis in the up-down direction. In other words, like the example of FIG. 3A, opening 12 is line-symmetrical with respect to axis of symmetry 18y.

[0089] Furthermore, neither of the two sides adjacent to side 15d is perpendicular to side 15d. The two sides adjacent to side 15d are side 15e, which is the side to the left of side 15d, and side 15c, which is the side to the right of side 15d. Both of these sides intersect side 15d at an angle, so they are not perpendicular to side 15d.

[0090] 4A, for example, the variation between the upper left and upper right may be large, while the variation between the lower left and lower right may be relatively small, depending on the polarization direction of polarizing element 8. In this case, by shaping opening 12 as shown in FIG. 9A, it is possible to obtain the widest possible irradiation area while blocking light in the necessary areas.

[0091] 9B is a schematic diagram showing a variation of opening 12. In this example, similar to the example of FIG. 9A, opening 12 is not line-symmetrical about an axis in the left-right direction, but is line-symmetrical about an axis in the up-down direction. Furthermore, the two sides adjacent to side 15d are both perpendicular to side 15d. That is, sides 15e and 15c are both perpendicular to side 15d.

[0092] Also in this example, at least a part of the leftmost portion of opening 12 and at least a part of the rightmost portion are located at the same position in the up-down direction, but not on either side 15a or 15d. The leftmost portion of opening 12 is the entire side 15e, and the rightmost portion is the entire side 15c. If we define a part of the leftmost portion as side 15e excluding vertex 16d, and a part of the rightmost portion as side 15c excluding vertex 16c, then these are located at the same position in the up-down direction, and this same position is not on side 15a or 15d.

[0093] Furthermore, if a portion of the leftmost portion is defined as vertex 16e and a portion of the rightmost portion is defined as vertex 16b, their positions in the vertical direction are the same as the position of light source 6. Therefore, the positions in the vertical direction of at least a portion of the leftmost portion and at least a portion of the rightmost portion of opening 12 are the same as the position of light source 6. Opening 12 in this example also has trapezoidal left tapered portion 17a and right tapered portion 17b (not shown).

[0094] Depending on the material of the workpiece W, the orientation direction may be determined by the polarized light that hits it early on, and polarized light that hits it later may not affect the orientation direction. Therefore, for example, when the workpiece W is being transported from above and there is no problem if the lower half does not need to be shielded from light, by shaping the opening 12 as shown in Figure 9B, it is possible to achieve sufficient light shielding.

[0095] 9A and 9B, the lower left and lower right may be largely shaded and the upper left and upper right may be slightly shaded. This shape of opening 12 is also effective when there is little variation between the upper left and upper right.

[0096] Furthermore, other shapes such as an octagon may be adopted, and the specific shape of opening 12 is not limited, as long as it satisfies the following conditions: "having upper and lower sides that are parallel in the left-right direction," "at least a part of the leftmost portion and at least a part of the rightmost portion are at the same position in the up-down direction that is neither the position of the upper side nor the position of the lower side," and "at least one of the left ends of the upper side and the lower side or the right ends of the upper side and the lower side is not connected by a single straight side."

[0097] [Aperture Connection] FIG. 10 is a schematic diagram showing an example of a configuration in which the aperture 9 is connected. In this example, two apertures 9 (9a, 9b) are connected and used. As in the previous examples, aperture 9a is arranged vertically below rod-shaped light source 6a. Aperture 9b is also arranged vertically below light source 6b. That is, in this example, two light sources 6a and 6b are used. Furthermore, the two apertures 9a and 9b are arranged parallel to each other. In this example, both apertures 9a and 9b are arranged parallel to the XY plane.

[0098] The opening 12a of the aperture 9a has a pencil-like shape on only one side. That is, the right end of the opening 12a has the same right tapered portion 17b as the example in FIG. 3A, but the left end does not have the left tapered portion 17a and has the same shape as the left end of a rectangle. That is, the opening 12a has a pentagonal shape. Hereinafter, the sides of the opening 12a are referred to as sides 15a to 15e, counting clockwise from the top side. The vertices are referred to as vertices 16a to 16e, counting clockwise from the vertex at the right end of the side 15a.

[0099] Opening 12a also satisfies the condition that "it has sides 15a and 15d that are parallel in the left-right direction." Furthermore, its leftmost portion is the entire side 15e, and its rightmost portion is vertex 16b. Therefore, if we take a portion of the leftmost portion as the vertical midpoint of side 15e (shown by an "x") and a portion of the rightmost portion as vertex 16b itself, these satisfy the condition that "their vertical positions are the same, but not the position of side 15a or side 15d." Furthermore, this same position is the position of light source 6a.

[0100] Furthermore, the left end of side 15a (vertex 16e) and the left end of side 15d (vertex 16d) are connected by a single straight line, side 15e, but the right end of side 15a (vertex 16a) and the right end of side 15d (vertex 16c) are not connected by a single straight line. Therefore, the condition that "at least one of the left end of side 15a and the left end of side 15d, or the right end of side 15a and the right end of side 15d, is not connected by a single straight line" is satisfied.

[0101] Opening 12b has a shape obtained by left-right inverting opening 12a. That is, opening 12b is pentagonal and has only left tapered portion 17a. In addition, the above conditions are satisfied.

[0102] Furthermore, in this embodiment, at least a portion of opening 12a of aperture 9a overlaps with at least a portion of opening 12b of aperture 9b in the left-right direction at different positions in the up-down direction.

[0103] Openings 12a and 12b do not overlap when viewed from the Z direction. Therefore, openings 12a and 12b can be said to be at different positions in the up-down direction. Furthermore, openings 12a and 12b overlap each other when viewed from the Y direction. Therefore, openings 12a and 12b can be said to overlap each other in the left-right direction. The overlapping portions are the right tapered portion 17b of opening 12a and the left tapered portion 17a of opening 12b.

[0104] Similarly, when viewed from aperture 9b, at least a portion of opening 12b overlaps with at least a portion of opening 12a of aperture 9a at different positions in the up-down direction and in the left-right direction.

[0105] Furthermore, when considering a cross section along the YZ plane at the overlapping portion of openings 12a and 12b, the sum of the vertical widths of openings 12a and 12b is constant at any cross section position. That is, along vertical dashed axis 26 shown in FIG. 10, the sum of the vertical widths of openings 12a and 12b (thick line portion) is always constant even when the dashed axis is moved left or right. This sum is also equal to the width of the portion of opening 12a other than right tapered portion 17b and the width of the portion of opening 12b other than left tapered portion 17a.

[0106] When the width of the workpiece W is large, a single light source 6 alone cannot ensure a sufficient irradiation area, and two light sources 6 must be used side by side. In such cases, two apertures 9 must also be arranged side by side. Because the workpiece W is transported in the vertical direction, the exposure amount to the irradiation surface of the workpiece W depends on the vertical width of the opening 12, and if the openings 12 overlap in the vertical direction, it depends on the total width. In this example, the total vertical width is kept constant even at the joint between the openings 12a and 12b. Therefore, it is possible to make the total exposure amount from the two light sources 6 uniform even in the irradiation area corresponding to the joint.

[0107] FIG. 11A is a schematic diagram showing the irradiation width when two apertures 21 of the comparative example are joined together. FIG. 11B is a schematic diagram showing the irradiation width when two apertures 9 of the present technology are connected together.

[0108] In the apertures 21 of the comparative example, each aperture 21 is positioned so that the right end of the opening 22 of the left aperture 21 coincides with the left end of the opening 22 of the right aperture 21. In other words, if there is a gap between each aperture 22, the amount of exposure to the irradiation area corresponding to that gap will decrease. Furthermore, if each aperture 22 overlaps, the amount of exposure to the irradiation area corresponding to the overlapping portion will be excessive. Therefore, in order to achieve a uniform amount of exposure, it is desirable to position each aperture 21 so that the right and left ends of each aperture 22 are positioned equal to each other.

[0109] In FIG. 11A, the overlap width of aperture 21 of the comparative example is shown by a thick arrow, and the entire length (left and right sides) of opening 22 of the comparative example is shown by a solid arrow. The entire length of openings 12a and 12b of the present technology is shown by a dashed arrow. In FIG. 11B, the overlap width of apertures 9a and 9b of the present technology is shown by a thick arrow, the entire length of openings 12a and 12b of the present technology is shown by a solid arrow, and the entire length of opening 22 of the comparative example is shown by a dashed arrow. Since the overlap width of apertures 9a and 9b of the present technology is shorter than that of the comparative example, the entire length of each of openings 12a and 12b is longer than that of the comparative example. In this way, the present technology can ensure a larger irradiation width in the left-right direction than the comparative example.

[0110] 12A to 12F are graphs showing the uniformity of the exposure amount. The horizontal axis of the graph represents the position (mm) in the left-right direction of the irradiation surface, and the vertical axis represents the exposure amount. Figures 12A to 12C each show graphs for the case where two pencil-shaped apertures 9 of the present technology are connected. The polka-dot circles represent the exposure amount due to polarized light that passed through opening 12a of aperture 9a on the left. The white circles represent the exposure amount due to polarized light that passed through opening 12b of aperture 9b on the right. The black circles represent the total exposure amount. Figure 12A shows the graph for the case where the overlap width of the apertures 9 is 160 mm, Figure 12B shows the graph for the case where it is 176 mm, and Figure 12C shows the graph for the case where it is 192 mm.

[0111] 12D-12F each show graphs for a case where two rectangular apertures 21 of a comparative example are connected. The polka-dot circles indicate the exposure amount due to polarized light that passed through opening 22 of aperture 21 on the left. The white circles indicate the exposure amount due to polarized light that passed through opening 22 of aperture 21 on the right. The black circles indicate the total exposure amount. FIG. 12D shows a graph for an overlap width of apertures 21 of 224 mm, FIG. 12E shows a graph for an overlap width of 256 mm, and FIG. 12F shows a graph for an overlap width of 272 mm.

[0112] With this technology, comparing Figures 12B and 12C, the overlap width increases by 16 mm, and the uniformity of the exposure dose (black circles) increases by 4%, from ±4% to ±8%. On the other hand, with the comparative example, comparing Figures 12E and 12F, the overlap width also increases by 16 mm, but the uniformity of the exposure dose increases by 8%. Similarly, comparing Figures 12A and 12B, and Figures 12D and 12E, respectively, when the overlap width is reduced by the same amount, the uniformity increases by 3% with this technology, while it increases by 24% with the comparative example. In other words, when the overlap width is adjusted to the same extent, the present technology exhibits smaller fluctuations in uniformity than the comparative example.

[0113] FIG. 13 is a graph showing the relationship between overlap width and uniformity. The horizontal axis of the graph represents the overlap width of the apertures, and the vertical axis represents the uniformity of the exposure dose. The white circles represent the uniformity for the pencil-shaped aperture 9 of the present technology. The black circles represent the uniformity for the rectangular aperture 21 of the comparative example. As shown in the graph, the range of overlap widths where the uniformity is within ±10% is significantly wider for the present technology than for the comparative example.

[0114] When connecting two apertures, it is desirable to set the overlap width so that the exposure uniformity is as low as possible, but in reality, it is not possible to make a perfect adjustment, and some error may occur. With this technology, when the target exposure uniformity (for example, ±10%) is set, the adjustment margin (adjustment range of the overlap width) is wide, making it possible to easily adjust the overlap width.

[0115] Alternatively, two double-sided pencil-shaped apertures 9 each having a left tapered portion 17a and a right tapered portion 17b on both sides may be connected. Also, two apertures 9 having other shapes within the scope of the present technology may be connected. Alternatively, three or more apertures 9 may be connected.

[0116] FIG. 14 is a schematic diagram showing the operation of the moving mechanism. In this example, the polarized light irradiation unit 1 further includes a movement mechanism 27 that is capable of moving at least one of the plurality of apertures 9 in the left-right direction.

[0117] The position of aperture 9 relative to light source 6 differs in each of the upper, middle, and lower views of FIG. 14. In this manner, movement mechanism 27 (schematically shown) is capable of moving aperture 9 in the left-right direction. The means for moving aperture 9 by movement mechanism 27 may be any means such as well-known technology. Furthermore, the operation of movement mechanism 27 may be controlled by control unit 13.

[0118] This makes it possible to easily and accurately adjust the overlap width when connecting two apertures 9. In this case, the position of only one of the apertures 9 may be adjustable, or the positions of both of the apertures 9 may be adjustable.

[0119] [Position of aperture and polarizing element] In the present technology, a polarizing element 8 and an aperture 9 are disposed between the light source 6 and the workpiece W. Furthermore, in the example of FIG. 1 etc., the aperture 9 is disposed between the polarizing element 8 and the workpiece W, but conversely, the polarizing element 8 may be disposed between the aperture 9 and the workpiece W. That is, the aperture 9 may be disposed above the polarizing element 8 (on the light source 6 side). Furthermore, the polarizing element 8 and the aperture 9 may be integrally configured. That is, the aperture 9 may be used as an outer frame, and the polarizing element 8 may be fitted into the entire opening 12.

[0120] [Direction of polarized light irradiation unit] When the workpiece W is placed at an angle to the horizontal, the polarized light irradiation unit 1 itself may also be placed at an angle, i.e., the polarizing element 8 and aperture 9 may also be placed at an angle to the horizontal. When there is a restriction on the space for placing the polarized light irradiation unit 1, such an arrangement may also be adopted.

[0121] It is also possible to combine at least two of the above-described features of the present technology. Furthermore, the various effects described above are merely examples and are not intended to be limiting, and other effects may also be achieved. [Explanation of symbols]

[0122] 1...Polarized light irradiation unit 2...Feed roller 3... Winding roller 6...Light source 8...Polarizing element 9...Aperture 12...Aperture 13...Control unit 15...sides 16...Vertex 17...Tapered section 18...Axis of symmetry 27...Movement mechanism

Claims

1. A polarized light irradiation unit that irradiates a target with polarized light, a light source having a rod shape; a polarizing element that polarizes the light emitted from the light source and is disposed between the light source and the object; one or more light blocking plates each having a flat plate shape, each having an opening, and disposed between the light source and the object; When the longitudinal direction of the light source is the left-right direction, and the direction perpendicular to the longitudinal direction and parallel to the light blocking plate is the up-down direction, the opening has an upper side and a lower side that are parallel to the left-right direction, at least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are located at the same position in the up-down direction, which is neither the position of the upper side nor the position of the lower side; At least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side is not connected by a straight line. Polarized light irradiation unit.

2. The polarized light irradiation unit according to claim 1 , At least one of the leftmost portion of the opening or the rightmost portion of the opening consists of only one point. Polarized light irradiation unit.

3. 3. The polarized light irradiation unit according to claim 1, At least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are positioned at the same position in the up-down direction as the light source. Polarized light irradiation unit.

4. 3. The polarized light irradiation unit according to claim 1, The opening has at least one of a left tapered portion whose diameter in the vertical direction decreases toward the left side and a right tapered portion whose diameter in the vertical direction decreases toward the right side. Polarized light irradiation unit.

5. The polarized light irradiation unit according to claim 2, The opening has a hexagonal shape that is line-symmetrical with respect to the vertical axis, and two sides of the hexagon are the upper side and the lower side. Polarized light irradiation unit.

6. The polarized light irradiation unit according to claim 5 , The opening is symmetrical with respect to the left-right axis. Polarized light irradiation unit.

7. The polarized light irradiation unit according to claim 5 , The opening is not symmetrical about the left-right axis, Neither of the two sides adjacent to the bottom side is perpendicular to the bottom side Polarized light irradiation unit.

8. The polarized light irradiation unit according to claim 5 , The opening is not symmetrical about the left-right axis, The two sides adjacent to the bottom side are both perpendicular to the bottom side. Polarized light irradiation unit.

9. 3. The polarized light irradiation unit according to claim 1, The object has a flat plate shape, The light blocking plate is disposed parallel to the object. Polarized light irradiation unit.

10. 3. The polarized light irradiation unit according to claim 1, the object and the polarizing element have a flat plate shape, The polarizing element is arranged parallel to the object. Polarized light irradiation unit.

11. 3. The polarized light irradiation unit according to claim 1, The light blocking plate is disposed between the polarizing element and the object. Polarized light irradiation unit.

12. 3. The polarized light irradiation unit according to claim 1, the one or more light-shielding plates are a plurality of light-shielding plates arranged parallel to each other, In each of the plurality of light-blocking plates, at least a portion of the opening overlaps with at least a portion of the opening of at least one other light-blocking plate in the left-right direction at different positions in the up-down direction. Polarized light irradiation unit.

13. The polarized light irradiation unit according to claim 12, further comprising: a moving mechanism that can move at least one of the plurality of light blocking plates in the left-right direction; Polarized light irradiation unit.

14. 3. The polarized light irradiation unit according to claim 1, The polarizing element is a wire grid polarizing element. Polarized light irradiation unit.

15. A polarized light irradiation unit that irradiates a target with polarized light, a light source having a rod shape; a polarizing element that polarizes the light emitted from the light source and is disposed between the light source and the object; one or more light blocking plates each having a flat plate shape, each having an opening, and disposed between the light source and the object; When the longitudinal direction of the light source is the left-right direction, and the direction perpendicular to the longitudinal direction and parallel to the light blocking plate is the up-down direction, the opening has an upper side and a lower side that are parallel to the left-right direction, at least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are located at the same position in the up-down direction, which is neither the position of the upper side nor the position of the lower side; At least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side is not connected by a straight line. a polarized light irradiation unit; a conveying unit that conveys the object along the up-down direction; A polarized light irradiation device comprising:

16. Light emitted from a rod-shaped light source is polarizing the light by a polarizing element disposed between the light source and the object; a flat plate-shaped light source having an opening, and a portion of the light being blocked by one or more light blocking plates disposed between the light source and the object; A polarized light irradiation method for irradiating the object with polarized light, When the longitudinal direction of the light source is the left-right direction, and the direction perpendicular to the longitudinal direction and parallel to the light blocking plate is the up-down direction, the opening has an upper side and a lower side that are parallel to the left-right direction, at least a part of the leftmost portion of the opening and at least a part of the rightmost portion of the opening are located at the same position in the up-down direction, which is neither the position of the upper side nor the position of the lower side; At least one of the left end of the upper side and the left end of the lower side, or the right end of the upper side and the right end of the lower side is not connected by a straight line. Polarized light irradiation method.

Images