Light irradiation apparatus and exposure apparatus provided with the same

Abstract

The present invention provides a light irradiation device for an exposure device capable of performing a photo-alignment process with a simple structure. The light irradiation device (10) is composed of a light source (12) having a plurality of LEDs (16), and a polarization element (14) that receives light (L) from the light source (12) and causes the transmitted light (L) to be irradiated on a workpiece (X). Furthermore, the optical axis (CL) of each LED (16) is set to have a first angle (θ1) with respect to the workpiece (X), and the light distribution angle of the light (L) radiated from each LED (16) is set to be half of the first angle (θ1), i.e., a second angle (θ2), which is smaller than the first angle (θ1). Furthermore, the illuminance or the cumulative light amount of the light toward the workpiece (X) or an exposure surface (A) is adjusted by changing the power input to the LEDs (16).

Description

Technical Field

[0001] This invention relates to a light irradiation apparatus for exposure in the manufacture of liquid crystal panels, and an exposure apparatus having the same. Background Technology

[0002] When using liquid crystal as a TN-type display panel, it will not work properly if only liquid crystal is sealed between two glass substrates and a voltage is applied to the transparent electrodes formed on the inner surfaces of these glass plates. This is because the liquid crystal molecules are in a disordered state.

[0003] For liquid crystals to operate normally in the TN mode, the liquid crystal molecules need to be oriented in a certain direction and their upright orientation needs to be consistent. Specifically, the liquid crystal molecules are oriented at an angle of approximately 3° relative to the glass substrate; this angle is called the pretilt angle.

[0004] Furthermore, in a pair of glass substrates having liquid crystal alignment properties, one glass substrate is configured to be aligned in the X direction, and the opposite glass substrate is configured in the Y direction orthogonal to the X direction (TN method).

[0005] Thus, liquid crystal alignment is required in the manufacturing of liquid crystal panels, and physical friction treatment of the glass substrate surface has been performed (for example, Patent Document 1). This friction treatment refers to a method of forming a film that can align liquid crystal molecules in a certain direction by rubbing an organic polymer film formed on a glass substrate with a long-pile cloth or the like.

[0006] With the widespread adoption of friction processing, the fast-response TN method has become more common, enabling LCD panels to be mass-produced at low cost with stable performance. As a result, LCD monitors have become widely used as display monitors for computers and other OA equipment, as well as monitors for game consoles.

[0007] However, the friction method has issues such as lack of uniformity, potential electrostatic damage to TFTs, and the adhesion of powder and dust generated during friction, which affect reliability.

[0008] Furthermore, as mentioned above, in the TN method, which represents a horizontally oriented liquid crystal mode, the pretilt angle that can be achieved by friction is about 3°, which is difficult for a display panel that is designed for low-voltage driving and high-speed response liquid crystal modes.

[0009] To address the problems associated with this type of friction, an exposure machine capable of performing photo-orientation processing has been proposed. In this machine, a long-arc mercury lamp has been used as the light source.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 2007-17475 Summary of the Invention

[0013] The problem that the invention aims to solve

[0014] However, it is believed that there are also problems with exposure machines that use long-arc mercury lamps. Typically, the photosensitivity of the exposure material is set so that it reacts with light of a specific wavelength. When the spectroscopic characteristics of the light from the mercury lamp are observed, it can be seen that the light consists of a large number of bright lines of mercury.

[0015] Therefore, when a mercury lamp is used as the light source for exposure, since there is more light with wavelengths that deviate from the photosensitive characteristics of the exposed material, it is possible that the exposed material may be overexposed due to light with wavelengths that deviate from the photosensitive band.

[0016] Of course, wavelength-selective reflective films can also be used to cut off light rays that deviate from the photosensitive characteristics (short-wavelength side and long-wavelength side), but this requires narrow-band cutoff filters (bandpass filters) and high precision, which will increase the cost of the device.

[0017] In addition, since the light emitted from the long arc of the mercury lamp spreads over a wide area, it is difficult to control the important angle of illumination of the light from the mercury lamp in order to implement light orientation treatment. For example, methods such as using blinds to block excess light have been studied, but in this case, there are other problems such as reduced utilization efficiency of the light emitted from the mercury lamp.

[0018] In addition, there is a method that illuminates collimated (parallelized) light at an angle relative to a glass substrate, but this method is considered to have problems such as large size and high cost due to the complexity of the optical system.

[0019] The present invention was made in view of the above-mentioned problems, and its object is to provide a light irradiation device for an exposure apparatus that can perform light orientation processing with a simple structure.

[0020] Technical solutions for solving the problem

[0021] According to one aspect of the present invention, a light irradiation device is provided, characterized in that it comprises:

[0022] The light source has multiple LEDs; and

[0023] A polarizing element that receives light from the light source and causes the transmitted light to illuminate the workpiece.

[0024] The optical axis of each LED has a first angle relative to the workpiece.

[0025] The second angle, which is half of the light distribution angle emitted from each of the LEDs, is set to be smaller than the first angle.

[0026] The illuminance or cumulative light intensity of the light directed onto the workpiece or exposure surface is adjusted by varying the power input to the LED.

[0027] Preferably,

[0028] The light source comprises multiple LED modules configured with multiple of the aforementioned LEDs.

[0029] The multiple light sources are arranged along the direction of movement of the workpiece.

[0030] The power input to the multiple LEDs configured in the multiple LED modules arranged in a straight line along the direction of movement of the workpiece and located in different light sources is adjusted by a driving power supply.

[0031] Preferably,

[0032] The light irradiation device also includes a measuring device that measures the illuminance of the workpiece or the exposed surface.

[0033] The unevenness of light on the workpiece or the exposed surface is calculated based on the value of illuminance or cumulative light intensity measured by the measuring instrument, and the unevenness is eliminated by changing the power input to the LED located at the position corresponding to the unevenness.

[0034] Preferably,

[0035] The polarizing element has a shape that is longer in the direction of illumination of the light emanating from the light source.

[0036] Preferably,

[0037] The polarization element is composed of multiple wire grids.

[0038] Each wire grid is formed in a trapezoidal shape.

[0039] In a direction orthogonal to the direction of illumination of the light from the light source, the lower side of a trapezoid and the upper side of an adjacent trapezoid are arranged in a straight line.

[0040] Preferably,

[0041] The number of polarizing elements is less than the number of light sources.

[0042] Invention Effects

[0043] According to the light irradiation apparatus of the present invention, by tilting the optical axes of a plurality of LEDs relative to the workpiece at a first angle, a second angle, which is equivalent to half of the orientation angle of the light emitted from each LED, is set to be smaller than the first angle, thereby all the light emitted from each LED is more oriented toward the optical axis side of the LED than the vertical line from the LED toward the workpiece.

[0044] Therefore, it is possible to provide a light irradiation device for an exposure apparatus that can perform light orientation processing with a large amount of light and an effective irradiation angle in a simple structure. Attached Figure Description

[0045] Figure 1 This is a diagram showing the application of the light irradiation device 10 of the present invention.

[0046] Figure 2 This is a front view of a light irradiation device 10 that includes a light source 12 composed of multiple LED modules 100.

[0047] Figure 3 This is a perspective view of a light irradiation device 10 equipped with an angle adjustment mechanism 110.

[0048] Figure 4 This is a side view of the light irradiation device 10 equipped with an angle adjustment mechanism 110.

[0049] Figure 5 This is a front view of a light irradiation device 10 equipped with a width-direction position adjustment mechanism 120.

[0050] Figure 6 This is a perspective view of a light source 12 having a serrated LED base 130.

[0051] Figure 7 This is a side view of the light source 12, which has a serrated LED base 130.

[0052] Figure 8 This is a perspective view of a light irradiation device 10 equipped with an overall angle adjustment mechanism 152.

[0053] Figure 9 This is a side view of the light irradiation device 10 equipped with an overall angle adjustment mechanism 152.

[0054] Figure 10 This is a front view of the light irradiation device 10 involved in Modified Example 1.

[0055] Figure 11 This is a side view of the light irradiation device 10 involved in Modified Example 1.

[0056] Figure 12 This is a front view of the light irradiation device 10 involved in Modified Example 2.

[0057] Figure 13 This is a side view of the light irradiation device 10 involved in Modification Example 2.

[0058] Figure 14 This is a perspective view of the light irradiation device 10 involved in Modification Example 3.

[0059] Figure 15 This is a side view of another light irradiation device 10 involved in Modified Example 3.

[0060] Figure 16 This is a side view of the light irradiation device 10 involved in Modified Example 8.

[0061] Figure 17 This is a top view showing the polarization element 14 involved in Modified Example 9.

[0062] Figure 18 This is a top view showing the polarization element 14 involved in Modified Example 10.

[0063] Figure 19 This is a top view of the light irradiation device 10 involved in Modification Example 11.

[0064] Figure 20 This is a perspective view of the light irradiation device 10 involved in Modification Example 11.

[0065] Figure 21 This is a top view of the light irradiation device 10 involved in Modification Example 11.

[0066] Figure 22 This is a diagram illustrating an example of the drive power supply 180 involved in Modification 11.

[0067] Figure 23 This is a diagram representing LED module 100.

[0068] Figure 24 This is a diagram showing the positional relationship between the LED groups Y and Z and the measuring device 190 on the exposure surface A, as involved in Modification Example 11.

[0069] Figure 25 This is a diagram showing the range of light irradiation exposure surface A from LED group Y and Z in modified example 11.

[0070] Figure 26 This is a diagram showing the range of light exposure surface A from LED group Y, Z, and V in modified example 11. Detailed Implementation

[0071] (Structure of the light irradiation device 10)

[0072] The light irradiation apparatus 10 according to an embodiment of the present invention will be described below. The light irradiation apparatus 10 is mainly assembled in an exposure apparatus for exposure during the manufacture of a liquid crystal panel. For example... Figure 1 As shown, the light irradiation device 10 generally includes a light source 12 and a polarizing element 14.

[0073] The light source 12 is a component that illuminates the exposure light L toward the exposure surface A on which the workpiece (exposed object) X is placed. In this embodiment, a plurality of LEDs 16 are used. These LEDs 16 illuminate the exposure light L in a manner that scans the workpiece X, which is moving in a certain direction on the exposure surface A. Therefore, the light source 12 is formed by arranging a plurality of LEDs 16 in approximately series in a direction orthogonal to the moving direction of the workpiece X. Of course, it is also possible that the light illuminating device 10 moves relative to the workpiece X to illuminate the exposure light L, or that both the workpiece X and the light illuminating device 10 move.

[0074] Furthermore, each LED 16 constituting the light source 12 is tilted relative to the workpiece X (i.e., relative to the exposure surface A) such that the optical axis CL of these LEDs has a first angle θ1 (i.e., incident angle θ1) relative to the workpiece X. By using an alignment film made of light with minimal deviation from the oblique irradiation angle component in the liquid crystal panel, a stable pretilt angle and alignment state can be achieved, enabling the liquid crystal panel to realize any alignment mode.

[0075] In addition, such as Figure 2 As shown, multiple LEDs 16 can also be grouped into one LED module 100, and the light source 12 can be formed by arranging multiple LED modules 100, for example, in one direction.

[0076] In addition, such as Figure 3 as well as Figure 4 As shown, an angle adjustment mechanism 110 can also be provided to adjust the illumination angle of the light source 12 as a whole relative to the polarizing element 14. The exemplified angle adjustment mechanism 110 has a rotation shaft 112 extending along the direction in which the plurality of LED modules 100 constituting the light source 12 are arranged. By rotating the rotation shaft 112, the illumination angle of the light source 12 as a whole relative to the polarizing element 14 can be adjusted.

[0077] In addition, such as Figure 5 As shown, a width-direction position adjustment mechanism 120 can also be provided to adjust the position of the light source 12 relative to the polarizing element 14 in the direction in which the multiple LED modules 100 are arranged. This allows for adjustment in a way that reduces uneven illuminance of the light emitted from each LED module 100.

[0078] Alternatively, instead of arranging each LED module 100 relative to the polarizing element 14 at a given angle, it can be configured as follows: Figure 6 as well as Figure 7 As shown, an LED base 130 with a sawtooth cross section is prepared, and LEDs 16 are respectively arranged on inclined surfaces 132 with a given angle relative to the polarizing element 14 and corresponding to each tooth.

[0079] return Figure 1 The second angle θ2, which is half of the light distribution angle of the light L emitted from each LED16, is set to be smaller than the first angle θ1 mentioned above.

[0080] The polarizing element 14 is an element that polarizes only the light component vibrating in one direction from the light irradiated by the light source 12. In this embodiment, a wire-grid polarizing element is used. A wire-grid polarizing element is an element in which a wire grid is formed on one surface of a transparent substrate (glass substrate). In this embodiment, the surface 18 on which the wire grid is formed can be the surface of the polarizing element 14 on the side facing the light source 12, or it can be the surface on the opposite side of the light source 12. Furthermore, the polarizing element 14 is preferably arranged parallel to the workpiece X (exposure surface A).

[0081] As a variation of the polarization element 14, such as Figure 4 As shown, the optical filter 30, polarizing element 14, and cover component 40 can also be arranged sequentially from the side closest to the light source 12, and these optical filters 30, polarizing element 14, and cover component 40 constitute the polarizing element group 150.

[0082] An optical filter 30 is disposed between the light source 12 and the polarizing element 14. It is a component that selectively allows light L of a given wavelength or longer to pass through from the light L emitted from the light source 12, and a wavelength-selective film is formed on its surface. Furthermore, like the polarizing element 14, the optical filter 30 is preferably disposed parallel to the workpiece X (exposure surface A). Moreover, as the optical filter 30, a long-pass filter that allows light of a given wavelength or longer to pass through, or a band-pass filter that allows light of a given wavelength range to pass through while blocking light with wavelengths longer or shorter than that, can be used, provided the following conditions are met. Additionally, the optical filter 30 can also be disposed on the side of the polarizing element 14 opposite to the light source 12 side.

[0083] The cover member 40 is a plate, such as glass, through which light L from the light source 12 passes. It is positioned in the polarizing element 14 opposite the forming surface 18 of the wire grid, and is disposed approximately parallel to the workpiece X. That is, as shown, when the forming surface 18 of the wire grid in the polarizing element 14 is formed on the side opposite to the light source 12 side, the cover member 40 is also disposed on the side of the polarizing element 14 opposite to the light source 12 side. Conversely, when the forming surface 18 of the wire grid in the polarizing element 14 is formed on the light source 12 side (not shown), the cover member 40 is also disposed on the light source 12 side of the polarizing element 14.

[0084] Alternatively, the anti-reflective treatment such as an anti-reflective film may not be applied to the surface (both sides) of the cover component 40, but it is preferable to apply the anti-reflective treatment such as an anti-reflective film to one or both surfaces.

[0085] Furthermore, it is preferable to seal the space S between the cover member 40 and the forming surface 18 of the wire grid in the polarization element 14. For example, it is advisable to provide a retaining frame 42 that holds the periphery of the cover member 40 and the polarization element 14, and use the retaining frame 42 to seal the space S between the cover member 40 and the forming surface 18 of the wire grid in the polarization element 14.

[0086] Furthermore, the aforementioned "sealed" refers to the degree to which tiny solid particles such as siloxane compounds do not intrude into the space S, and does not require "sealed" in the complete sense.

[0087] Furthermore, the polarization element 14 preferably uses a so-called "reflective" wire grid. This is because, if it is a "reflective" type, the wire grid will be heated by the light L from the light source 12, causing the temperature of the enclosed space to rise undesirably, thus reducing the likelihood of damage to the wire grid formation surface 18 and the like.

[0088] Furthermore, for the purpose of cooling the enclosed space S, components constituting the space S, such as the cover component 40, the polarizing element 14, or the retaining frame 42, can also be cooled by forced air cooling or water cooling.

[0089] Alternatively, a polarization element group angle adjustment mechanism can be provided to adjust the illumination angle of the entire polarization element group 150 relative to the workpiece X (exposure surface A) or the light source 12. This polarization element group angle adjustment mechanism can be a mechanism that adjusts the angle of the optical filter 30, polarization element 14, and cover component 40 together, or it can be a mechanism that adjusts the angle of the optical filter 30, polarization element 14, and cover component 40 separately.

[0090] Furthermore, such as Figure 8 as well as Figure 9 As shown, the angle adjustment mechanism 110 of the light source 12 and the angle adjustment mechanism of the polarizing element group can also be combined into an integrated angle adjustment mechanism 152 that can adjust the angle of the light source 12 and the polarizing element group 150 relative to the workpiece X (exposure surface A). The illustrated integrated angle adjustment mechanism 152 has an integrated rotation shaft 154 that extends along the direction in which the plurality of LED modules 100 constituting the light source 12 are arranged and the direction in which the same polarizing element group 150 extends. By rotating the integrated rotation shaft 154, the overall illumination angle of the light source 12 and the polarizing element group 150 relative to the workpiece X (exposure surface A) can be adjusted.

[0091] Alternatively, a polarization element group width direction position adjustment mechanism can be provided to adjust the position of the polarization element group 150 in the direction in which the polarization element group 150 extends (the direction in which the multiple LED modules 100 are arranged).

[0092] Alternatively, the width direction position adjustment mechanism 120 of the light source 12 and the width direction position adjustment mechanism of the polarization element group mentioned above can be combined into an overall width direction position adjustment mechanism that adjusts the position of the light source 12 and the polarization element group 150 in the direction in which the polarization element group 150 extends (the direction in which the multiple LED modules 100 are arranged).

[0093] (Effect of the light irradiation device 10 according to this embodiment)

[0094] According to the light irradiation device 10 of this embodiment, by tilting the optical axis CL of the plurality of LEDs 16 relative to the workpiece X by a first angle θ1, a second angle θ2, which is equivalent to half of the orientation angle of the light L emitted from each LED 16, is set to be smaller than the first angle θ1. As a result, all of the light L emitted from each LED 16 will be more toward the optical axis CL side of the LED 16 than the perpendicular line from the LED 16 toward the workpiece X.

[0095] Therefore, a light irradiation device 10 for an exposure apparatus can be provided, which can perform light orientation processing with a large amount of light and an effective irradiation angle with a simple structure.

[0096] (Variation Example 1)

[0097] like Figure 10 as well as Figure 11 As shown, reflectors 160 can also be provided at both ends of the light source 12 and the polarizing element group 150 in the width direction. This prevents the illuminance at both ends of the light irradiation device 10 on the workpiece X (exposure surface A) from decreasing.

[0098] (Variation Example 2)

[0099] In addition, such as Figure 12 as well as Figure 13 As shown, a width-direction reflector 164 extending along the width direction of the light source 12 and the polarization element group 150 may also be provided, which reflects a portion of the light L that is irradiated in a direction approximately orthogonal to the direction (width direction) extending from the light source 12, i.e., the light L that does not enter the polarization element group 150.

[0100] Alternatively, the light irradiation device 10 may include both the reflector 160 described in Modified Example 1 and the width-direction reflector 164 described in Modified Example 2.

[0101] (Variation Example 3)

[0102] like Figure 14 As shown, a light source unit 170 can also be constructed by configuring multiple sets of the above-mentioned light irradiation devices 10.

[0103] Furthermore, when constructing the light source unit 170, it is preferable that the angle of each light irradiation device 10 can be adjusted individually. Moreover, it is also preferable that the angle of each LED module 100 and each polarization element group 150 included in each light irradiation device 10 can be adjusted individually.

[0104] Alternatively, the light source unit 170 can be composed of fewer polarizing element groups 150 than the number of light sources 12 composed of multiple LED modules 100. For example, in Figure 15 In the light source unit 170 shown, only one polarizing element group 150 is used instead of five light sources 12. In this way, by constituting the light source unit 170 with fewer polarizing element groups 150 than the number of light sources 12, it is possible to avoid the vignetting of the light L emitted from the light source 12 that may occur when there is a one-to-one correspondence between the light source 12 and the polarizing element group 150 (the number of light sources 12 is the same as the number of polarizing element groups 150), which is preferable in this respect.

[0105] (Variation Example 4)

[0106] If the illuminance or cumulative light intensity of workpiece X (exposed surface A) measured by the measuring instrument for measuring the illuminance of workpiece X (exposed surface A) deviates from a given specified value, it is preferable to adjust the illuminance or cumulative light intensity by changing the power input to each LED 16.

[0107] (Variation Example 5)

[0108] Preferably, the unevenness of light L on workpiece X (exposure surface A) is calculated based on the value of illuminance or cumulative light intensity of workpiece X (exposure surface A) measured by a measuring instrument that measures the illuminance of workpiece X (exposure surface A), and the unevenness is eliminated by changing the power input to LED16 located at the position corresponding to the unevenness.

[0109] Furthermore, if uneven illuminance or uneven cumulative light on workpiece X (exposure surface A) occurs at the boundaries between polarization element groups 150 or at the boundaries of each component of polarization element group 150 (polarization element 14, optical filter 30, cover member 40), it is preferable to eliminate the unevenness by changing the power input to LED 16 located at the position corresponding to the boundary.

[0110] (Variation Example 6)

[0111] When workpiece X is exposed by moving workpiece X or at least moving light source 12 in a certain direction, and unevenness in the cumulative light amount occurs in the direction of movement, it is preferable to eliminate the unevenness in light amount by changing the power input to the corresponding LED 16 during the movement.

[0112] (Variation Example 7)

[0113] The illuminance or cumulative light intensity can also be adjusted by continuously turning each LED16 on or off.

[0114] Alternatively, the illuminance or cumulative light intensity can be adjusted by repeatedly turning each LED16 on and off.

[0115] (Variation Example 8)

[0116] like Figure 16 As shown, it is preferable that the shape of the (wire grid) polarizing element 14 constituting the polarizing element group 150 is longer in the irradiation direction of the light L irradiated from each light source 12.

[0117] (Variation Example 9)

[0118] Furthermore, the shape of the wire grid constituting the polarization element 14, such as Figure 17 As shown, a wire grid can also be formed on a disc-shaped wafer, cut into rectangles, and three such rectangles can be arranged in a direction orthogonal to the irradiation direction of the light L irradiated from each light source 12 (the direction in which each LED module 100 is arranged).

[0119] (Variation Example 10)

[0120] Furthermore, the shape of the wire grid constituting the polarization element 14, such as Figure 18 As shown, the wire grid can also be formed into a generally trapezoidal shape and configured such that, in a direction orthogonal to the illumination direction of the light L irradiated from each light source 12 (the direction in which each LED module 100 is arranged), the lower side of one generally trapezoid and the upper side of an adjacent generally trapezoid are arranged in a generally straight line. In this way, by configuring the wire grid into a generally trapezoidal shape, compared with the case of Modified Example 9, although the range of uneven illuminance or uneven cumulative light amount in the illumination direction of the light L irradiated from each light source 12 is wider, the degree of unevenness is correspondingly smaller, so adjustment becomes easier, and therefore it is more preferred.

[0121] (Variation Example 11)

[0122] In addition, such as Figure 19 as well as Figure 20 As shown, multiple arrangements can also be made along the direction of movement of workpiece X (three in variation 11). Figure 2The light source 12 is shown. In this case, each LED module 100 in each light source 12 is arranged in a straight line along the moving direction of the workpiece X (by...). Figure 19 (The LED modules 100 enclosed by a single-dot dashed line in the image). Hereinafter, a plurality of LED modules 100 arranged in a straight line and configured for different light sources 12 will be referred to as "LED modules 100 in the same group". Furthermore, the LED modules 100 in the same group may or may not be on the same plane.

[0123] Moreover, such as Figure 21 As shown, a single driving power supply 180 supplies power to the LED modules 100 in the same group. Therefore, the amount of light emitted from the LED modules 100 in the same group can be adjusted via a single driving power supply 180. Furthermore, in Figure 21 The diagram shows an example of supplying power in parallel to each LED module 100 in the same group from a single power supply 180, but it is also possible to supply power in series to each LED module 100 in the same group from a single power supply 180 instead.

[0124] Here, a modified example of the drive power supply 180 will be described, as follows: Figure 22 As shown in (a), a dimming signal is input to a driver power supply 180, and power is output to a group of LED modules 100. Alternatively, as shown in (a),... Figure 22 As shown in (b), a dimming signal is input, and power is output to multiple groups (two in this example) of LED modules 100. Furthermore, it can also be done as follows: Figure 22 As shown in (c), multiple (two in this example) dimming signals are input to the drive power supply 180, and power is output to multiple (two in this example) LED modules 100 respectively.

[0125] Furthermore, in each of the LED modules 100 involved in this variation, such as Figure 23 As shown, five LEDs arranged in a straight line are considered as one LED group, and two LED groups are arranged in parallel to each other.

[0126] The method for adjusting the amount of light emitted from each LED 16 via the drive power supply 180 when using an LED module 100 configured with two sets of LED groups Y and Z is described.

[0127] like Figure 24 As shown, an illuminance measuring device 190 is installed on the exposure surface A at a position corresponding to the midpoint between one LED group Y and the other LED group Z. The measuring device 190 then measures the amount of light emitted from one LED group Y and the amount of light emitted from the other LED group Z.

[0128] Specifically, the measuring device 190, positioned on the exposure surface A, moves in the movement direction of the workpiece X while measuring the cumulative light intensity (scanning measurement) of the LED modules 100 in the same group. Once the measurement of the light intensity from the LED modules 100 in that group is complete, the position of the measuring device 190 on the exposure surface A is moved in the width direction of the light source 12, and the cumulative light intensity from the LED modules 100 in adjacent groups is measured. This step is performed sequentially to measure the cumulative light intensity of all groups. Alternatively, the measuring device 190 can be moved relative to the measuring device 190 without moving the measuring device 190, or both can be moved.

[0129] Based on the light intensity measured by the measuring device 190, a dimming signal is input to the corresponding drive power supply 180 by a control device (not shown) to achieve the optimal light intensity. The power output from the drive power supply 180 receiving the dimming signal to the corresponding LED module 100 is adjusted, ultimately adjusting the light intensity emitted from LED group Y and LED group Z.

[0130] Thus, the adjustment of the light intensity based on the driver power supply 180 is performed on a per-LED module 100 basis. Of course, it is not limited to this; the adjustment can also be performed on a per-LED group basis, and then on a per-LED 16 basis, instead of on a per-LED module 100 basis.

[0131] In addition, such as Figure 25 As shown, the light distribution angle of the light from each LED 16 or the distance between the exposure surface A and the LED 16 is preferably set so that the positions P1 and P2 where the outer ends of the LEDs 16 belonging to different LED groups Y and Z and located in adjacent positions intersect the exposure surface A with the imaginary line (single-dotted line in the figure) extending vertically downward relative to the exposure surface A can receive light from two LEDs 16.

[0132] Based on this example, such as Figure 26 As shown, when three LED groups Y, Z, and V are used in one LED module 100, light from all (in this example, all three) of the LEDs 16 can be received between positions P1 and P2 where an imaginary line (the dashed line in the figure) extending vertically downward relative to the exposure surface A from the outer ends of the LEDs 16 belonging to the LED groups Y and V located at both ends intersects with the exposure surface A. The same applies when the number of LED groups is one or more.

[0133] The embodiments disclosed herein should be considered illustrative rather than limiting in all respects. The scope of the invention is defined not by the foregoing description but by the scope of the claims, and is intended to include all modifications within and equivalent to the scope of the claims.

[0134] Symbol Explanation

[0135] 10…light irradiation device, 12…light source, 14…polarizing element, 16…LED, 18…formation surface of grid

[0136] 30… Optical Filters

[0137] 40… Cover component, 42… Retaining frame

[0138] 100…LED module

[0139] 110… Angle adjustment mechanism, 112… Rotating shaft

[0140] 120… Width direction position adjustment mechanism, 130… LED base, 132… Inclined surface

[0141] 150…Polarization element group, 152…Overall angle adjustment mechanism, 154…Overall rotation shaft

[0142] 160…reflector, 164…width direction reflector

[0143] 170…light source unit

[0144] 180… drive power supply

[0145] 190… Measuring instrument

[0146] X…workpiece (exposed object), A…exposure surface, L…exposure light, CL…(LED16)optical axis, θ1…first angle, θ2…second angle, S…(space between cover component 40 and the forming surface 18 of the grid), Y…one LED group, Z…the other LED group, V…other LED groups.

Claims

1. An optical irradiation device, characterized by comprising: Possessing: a light source having a plurality of LEDs; and a polarization element that receives light from the light source and causes the transmitted light to be irradiated on a workpiece, the optical axis of each of the LEDs has a first angle with respect to the workpiece, a second angle, which is half of the light distribution angle of the light radiated from each of the LEDs, is set to be smaller than the first angle, the illuminance or the cumulative light amount of light to the workpiece or exposure surface is adjusted by varying the power input to the LEDs, the light source has a plurality of LED modules in which a plurality of the LEDs are arranged, a plurality of the light sources are arranged along the moving direction of the workpiece, the power input to a plurality of the LEDs arranged in a plurality of the LED modules arranged in a straight line and in different light sources along the moving direction of the workpiece is adjusted by one driving power source.

2. The light irradiation device according to claim 1, characterized in that, the light irradiation device further has a measurer that measures the illuminance of the workpiece or the exposure surface, a non-uniformity of light on the workpiece or the exposure surface is calculated from the value of the illuminance or the cumulative light amount of the workpiece or the exposure surface measured by the measurer, and the power input to the LEDs located at positions corresponding to the non-uniformity is varied to eliminate the non-uniformity.

3. The light irradiation device according to claim 1, characterized in that, the polarization element is in a shape that is long in the direction of irradiation of light irradiated from the light source.

4. The light irradiation device according to claim 1, characterized in that, the polarization element is composed of a plurality of wire grids, each of the wire grids is formed in a trapezoidal shape, in a direction orthogonal to the direction of irradiation of light irradiated from the light source, the lower side of one trapezoidal shape and the upper side of an adjacent trapezoidal shape are arranged in a straight line.

5. The light irradiation device according to claim 1, characterized in that, the number of the polarization elements is smaller than the number of the light sources.

6. An exposure device having the light irradiation device according to any one of claims 1 to 5.

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