TW201544801A - Polarization-axis detector, polarimetry equipment, polarimetry method and polarization light irradiation equipment - Google Patents

Abstract

The disclosed provides a polarization-axis detector, a polarimetry equipment, a polarimetry method and a polarization light irradiation equipment that can detect the polarization axis of polarization light with high precision even in a condition where the light from a light source has an illumination variation for every hour. The polarization-axis detector has a first polarization light detection element (311) having a rotatable light polarizer (311a) for detecting a polarization axis and a first illuminance sensor (311b) for detecting illuminance information of the polarization light from the light source which passes through the light polarizer (311a), and a second polarization light detection element (312) arranged in parallel to the first polarization light detection element (311) and having a second illuminance sensor (312a) for directly detecting the illuminance information of the polarization light from the light source. The polarimetry equipment calculates the polarization characteristic of polarization light from the light source based on the illuminance information detected by the first and second polarization light detection elements (311 and 312).

Description

Polarized axis detector, polarized light measuring device, polarized light measuring method and polarized light irradiation device

The present invention relates to a polarization axis detector for measuring a polarization axis of polarized light, a polarization measuring device, a polarization measuring method, and a polarized light irradiation device.

Recently, the alignment treatment of the alignment film of the liquid crystal display element including the liquid crystal panel and the alignment layer of the viewing angle compensation film has been gradually carried out by irradiating the polarized light of a predetermined wavelength to perform alignment, which is called a photo-alignment technique.

The illumination device used for the light alignment generally has a light source and a polarizer, and irradiates the polarized light obtained by passing the light of the light source through the polarizer. In the light alignment technique, it is important that the polarization axis of the polarized light that is irradiated by the irradiation device (the axis of the polarized light of the light irradiation portion) becomes a desired polarization axis. Therefore, after the angle of the polarizer is set to a predetermined angle, the polarized light is actually irradiated to measure the polarization axis, and if the desired polarization axis is not obtained, the operation of correcting the angle of the polarizer is required.

As a method for measuring the polarization axis of the prior art, for example, there is a patent document. Dedicated to the technology described in 1. In addition to the first polarizer provided in the illumination device, the second photon is provided for detecting the polarization axis, and the second polarizer is rotated while detecting the first polarizer and the second polarizer. Light, and based on the detection results, determine the polarization characteristics of the polarized light. Specifically, a change curve indicating a periodic change in the amount of light of the detected light when the second polarizer is rotated is obtained, and the polarization axis and the extinction ratio are measured as the polarization characteristics based on the change curve.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2014-20890

In the technique described in the above Patent Document 1, a discharge lamp is used as a light source. In the discharge lamp, there is a temporal change in the amount of light caused by the shaking of the arc, and the amount of light changes from moment to moment between the rotation of the second polarizer. However, in the technique described in Patent Document 1, the arc of the discharge lamp is not considered to be shaken, so that the measurement accuracy of the polarization axis of the polarized light is low.

In view of the above, an object of the present invention is to provide a polarization axis detector, a polarization measuring device, a polarization measuring method, and a polarizing light that can accurately detect a polarization axis of a polarized light even when light from a light source changes in illuminance per hour. Light illuminating device.

In order to solve the above problems, the polarizing axis detector of the present invention is a polarization axis detector that detects a polarization axis of a polarized light that is irradiated from a light source, and includes a first polarized light detecting unit that detects the polarized light. a first illuminance sensor for detecting rotation of the axis and a illuminance sensor for detecting illuminance information of the polarized ray from the light source passing through the detecting polarizer; and a second polarized light detecting portion having direct detection from the foregoing The second illuminance sensor of the illuminance information of the polarized light of the light source is disposed side by side in the first polarized light detecting portion.

In this manner, the second polarized light detecting portion that detects the polarized light from the light source that has not passed through the detecting polarizer is disposed side by side in the first polarized light detecting portion. Therefore, the two polarized light detecting sections can observe the shaking of the same polarized light, and the illuminance information of the polarized light detected by the second polarized light detecting unit can be set as the polarized light detected by the first polarized light detecting unit. The reference value of the illuminance information of the light. Therefore, even in the case where the illuminance of the polarized light from the light source changes every hour due to variations in the output of the light source, flicker, or the like, the detection of the polarization axis in consideration of the illuminance variation can be performed.

Further, in the polarization axis detector, the light source is a linear light source; and the first illuminance sensor and the second illuminance sensor are preferably arranged in a direction in which the linear light source extends.

In this way, when the light source is a linear light source, since the two illuminance sensors are arranged side by side in the direction in which the illuminance of the linear light source fluctuates less, the dependence of each place can be reduced, and the reliability can be measured. result.

Further, the polarization measuring device according to the present invention includes: any one of the polarizing axis detectors; and the polarized light measuring unit that measures the polarized light according to the illuminance information detected by the polarizing axis detector; The polarization light measuring unit includes a rotation control unit that rotates the detection polarizer into a plurality of designated angles, and an illuminance information correction unit that detects the first illuminance sensor based on the plurality of specified angles And detecting the detected illuminance value of the illuminance information, and detecting the illuminance value caused by the illuminance sensor, and calculating the reference illuminance value of the illuminance information detected by the second illuminance sensor Correcting a corrected illuminance value including an error caused by an hourly illuminance variation of the polarized light irradiated from the light source, and a polarization characteristic calculating unit that calculates a rotation angle indicating the detection polarizer a polarization ray angle characteristic in relation to a corrected illuminance value calculated by the illuminance information correction unit, and Reference light angle characteristic of light, polarized light calculated from the polarization characteristic of the light source.

In this manner, the reference illuminance value detected by the second polarized light detecting unit is used to correct the illuminance variation per hour of the polarized light from the light source included in the detected illuminance value detected by the first polarized light detecting unit. Since the error is made, the polarization ray angle characteristic for correcting the aforementioned error can be calculated. Therefore, even in a state where the polarized light from the light source is changed between the rotation of the detecting polarizer, the polarization characteristics of the polarized light can be calculated with high precision.

Further, in the polarization measuring device, the illuminance information correcting unit detects the detection detected by the first illuminance sensor The illuminance value is divided by the reference illuminance value detected by the second illuminance sensor in synchronization with the detection of the detected illuminance value, thereby calculating the corrected illuminance value. In this way, it is possible to appropriately correct the error caused by the illuminance variation of the polarized light from the light source included in the detected illuminance value by using only a relatively simple method.

Further, in the polarization measuring apparatus, the illuminance information correcting unit is configured to detect the second illuminance by subtracting the detected illuminance value detected by the first illuminance sensor from the plurality of specified angles Calculating the corrected illuminance value by calculating the difference between the average value of the reference illuminance values detected by the device and the detection of the detected illuminance value and the reference illuminance value detected by the second illuminance sensor It is better. In this way, it is possible to appropriately correct the error caused by the illuminance variation of the polarized light from the light source included in the detected illuminance value by using a relatively simple method of subtraction and average calculation.

Further, in the polarization measuring device, the polarization characteristic calculation unit includes the detection polarization in which the illuminance of the polarization ray from the light source that is passed through the detection polarizer is an extreme value based on the polarization ray angle characteristic. The rotation angle of the sub-rotation angle is preferably a polarization axis angle calculation unit that calculates the polarization axis angle of the polarized light as the polarization characteristic based on the specific rotation angle. Thereby, the polarization axis angle can be calculated with high precision.

Further, in the polarization measuring device, the polarization characteristic calculating unit includes an illuminance of a polarized ray from the light source that passes through the detecting polarizer based on the polarization ray angle characteristic. It is preferable that the maximum value and the minimum value are based on the specific maximum value and the minimum value, and the extinction ratio calculation unit that calculates the extinction ratio of the polarized light as the polarization characteristics. Thereby, the extinction ratio can be calculated with high precision.

Further, in the same manner as the polarization measuring method of the present invention, the method of measuring a polarized light that is irradiated with a polarized light from a light source includes: detecting a polarizer for detecting the polarization axis, rotating the plurality of specified angles, and detecting a step of detecting an illuminance value of the illuminance information of the polarized light from the light source of the detecting polarizer at each specified angle; and synchronizing with a timing of detecting illuminance information of the polarized ray from the light source passing through the detecting polarizer, The step of directly detecting the reference illuminance value of the illuminance information of the polarized light from the light source that does not pass the aforementioned detecting photon.

In this manner, the polarized light from the light source passing through the detecting polarizer and the polarized light from the light source that has not passed through the detecting polarizer can be detected at the same timing. Therefore, even when the reference illuminance value is set as the reference value of the detected illuminance value, and the illuminance of the polarized light from the light source fluctuates every hour, the detection of the polarization axis in consideration of the illuminance fluctuation can be performed.

Further, in the polarization measuring method, the method further includes: calculating, based on the detected illuminance value and the reference illuminance value detected by the plurality of specified angles, correcting a polarized ray that is emitted from the light source and included in the detected illuminance value a step of correcting the illuminance value of the error due to the fluctuation of the illuminance per hour; calculating a polarization ray angle characteristic indicating a relationship between the rotation angle of the detection polarizer and the corrected illuminance value; and the angle of the polarized ray The characteristics are benchmarks, calculated from the foregoing The step of polarizing light of the polarized light of the light source is preferably performed.

In this manner, the reference illuminance value can be used to correct the error caused by the illuminance variation per hour of the polarized light from the light source included in the detected illuminance value. Therefore, the polarization ray angle characteristic in which the aforementioned error is corrected can be calculated. Therefore, even in a state where the polarized light from the light source is changed between the rotation of the detecting polarizer, the polarization characteristics of the polarized light can be calculated with high precision.

Further, in the same manner as the polarized light irradiation device of the present invention, the polarized light irradiation device that irradiates the alignment film with the polarized light to perform light alignment includes a light-irradiating portion having a linear light source and along the linear light source. a plurality of polarizers disposed in a direction extending in a direction to illuminate a polarized ray that polarizes light of the linear light source by the polarizer; and any of the polarized light measuring devices that measure the polarized light that is irradiated by the light illuminating portion .

Thereby, the polarization measuring device can accurately measure the polarization characteristics of the polarized light that is irradiated from the light-irradiating portion. Therefore, it is possible to appropriately determine whether or not the polarization axis of the polarized light irradiated from the light irradiation portion is a desired polarization axis.

In the polarization axis detector of the present invention, the first polarized light detecting portion that detects the polarized light from the light source passing through the detecting polarizer is disposed, and the second polarized light that does not pass the polarizing light from the light source that does not pass the detecting polarizer is arranged side by side. Detection department. Therefore, even in the case where the illuminance of the polarized light from the light source changes hourly, it is possible to take into consideration that the illuminance is changed. Detection of the moving polarization axis.

Further, in the polarization measuring apparatus including the polarization axis detector, the reference illuminance value detected by the second polarized light detecting unit can be used to correct the detected illuminance value detected by the first polarized light detecting unit. Even in the case where the polarized light from the light source is changed between the rotation of the detecting polarizer, the polarization characteristics of the polarized light can be calculated with high precision.

10A, 10B‧‧‧Lighting Department

11‧‧‧Discharge lamp

12‧‧‧ lenses

13A‧‧‧ polarized subunit

13B‧‧‧ polarized subunit

13Aa‧‧‧ polarizer

13Ba‧‧‧ polarizer

13Ab‧‧‧Frame

13Bb‧‧‧Frame

14‧‧‧ lamp room

14a‧‧‧Light exit

20‧‧‧Transportation Department

21‧‧‧Workpiece table

22‧‧‧ Guides

23‧‧‧Electrical Stone

30‧‧‧Polarization measuring device

31‧‧‧Polar axis detector

32‧‧‧X direction transport department

33‧‧‧Y direction transport department

34‧‧‧Control Department

34a‧‧‧ Rotator Control Department

34b‧‧‧Input signal conversion unit

34c‧‧‧Polarization characteristic calculation unit

34d‧‧‧Portrait Display Department

34e‧‧‧Transport Control Department

35‧‧‧Monitor

100‧‧‧Polarizing light irradiation device

311‧‧‧First Polarized Light Detection Department

311a‧‧ ‧Detective polarizers (photodetectors)

311b‧‧‧First illumination sensor

311c‧‧‧Receiving Department

311d‧‧‧Support components

311e‧‧‧Rotary actuator

311f‧‧‧ Rotator

311g‧‧‧ openings

311h‧‧‧Air Supply Department

312‧‧‧Second Polarized Light Detection Department

312a‧‧‧Second illumination sensor

312b‧‧‧Receiving Department

312c‧‧‧Support components

312d‧‧‧ openings

312e‧‧‧Air Supply Department

W‧‧‧Workpiece

Fig. 1 is a schematic structural view showing a polarized light irradiation device of the present embodiment.

Fig. 2 is a cross-sectional view orthogonal to the longitudinal direction of the light-irradiating portion.

Fig. 3 is a cross-sectional view showing the longitudinal direction of the light-irradiating portion.

FIG. 4 is a view showing an example of arrangement of polarizers.

Fig. 5 is a perspective view showing a main part of a polarizing axis detector.

Fig. 6 is a cross-sectional perspective view showing a main portion of a polarization axis detector.

Fig. 7 is a schematic view showing the structure of a first polarized light detecting portion.

Fig. 8 is a block diagram showing the configuration of a polarization measuring device.

FIG. 9 is a flow chart showing the procedure of the polarization measurement process performed by the control unit.

Fig. 10 is a view showing an example of an angular characteristic of a polarized ray.

Fig. 11 is a view for explaining the effects of the embodiment.

Hereinafter, embodiments of the present invention will be described based on the drawings.

Fig. 1 is a schematic structural view showing a polarized light irradiation device of the embodiment.

The polarized light irradiation device 100 includes the light irradiation units 10A and 10B and the transport unit 20 that transports the workpiece W. Here, the workpiece W is a light alignment film, for example, a rectangular substrate having a size of a liquid crystal panel.

The polarized light irradiation device 100 irradiates the polarized light (polarized light) of a predetermined wavelength from the light-irradiating portions 10A and 10B, and linearly moves the workpiece W by the transport unit 20, thereby irradiating the optical alignment film of the workpiece W with the polarized light. Perform light alignment processor.

Each of the light-irradiating portions 10A and 10B includes a discharge lamp 11 that is a linear light source and a lens 12 that reflects the light of the discharge lamp 11. Further, the light-irradiating portion 10A includes a polarizing sub-unit 13A disposed on the light-emitting side thereof, and the light-irradiating portion 10B includes a polarizing sub-unit 13B disposed on the light-emitting side. Further, the light irradiation units 10A and 10B each include a lamp chamber 14. The discharge lamp 11, the lens 12, and the polarizing subunit 13A (or 13B) are housed in the lamp chamber 14.

The light irradiation unit 10A and the light irradiation unit 10B are arranged along the conveyance direction of the workpiece W in a state in which the longitudinal direction of the discharge lamp 11 is aligned in the direction (Y direction) orthogonal to the conveyance direction (X direction) of the workpiece W. (X direction) set side by side.

Here, a specific structure of the light irradiation unit 10A will be described.

2 is a cross-sectional view orthogonal to the longitudinal direction of the light-irradiating portion 10A, and FIG. 3 is a cross-sectional view in the longitudinal direction of the light-irradiating portion 10A. The light irradiation unit 10A has the same structure as the light irradiation unit 10B, and the structure of the light irradiation unit 10A will be described here.

The discharge lamp 11 is a long arc-shaped discharge lamp of a long strip shape. The discharge lamp 11 is, for example, irradiated with ultraviolet light having a wavelength of 200 nm to 400 nm.

As a material of the photo-alignment film, those who are aligned with light having a wavelength of 254 nm, aligned with light having a wavelength of 313 nm, or aligned with light having a wavelength of 365 nm are known, and the type of the light source is appropriately selected depending on the wavelength required.

Further, as the light source, a linear light source in which LEDs or LDs that emit ultraviolet light are arranged side by side in a straight line may be used. At this time, the direction of the side by side LED or LD is equivalent to the longitudinal direction of the lamp.

The lens 12 reflects the emitted light from the discharge lamp 11 to a predetermined direction, and as shown in FIG. 2, is an elliptical condensing mirror having an elliptical cross section. The lens 12 is disposed such that its longitudinal direction coincides with the longitudinal direction of the discharge lamp 11.

The lamp chamber 14 is attached to the bottom surface thereof, and has a light exiting opening 14a through which the light irradiated from the light-irradiating portion 10A passes. A polarizing subunit 13A having a polarizer for polarizing light passing therethrough is attached to the light exit opening 14a.

As shown in FIG. 4, the polarizer unit 13A is configured by arranging the plurality of polarizers 13Aa side by side in the frame 13Ab. In this manner, the plurality of polarizers 13Aa are arranged side by side along the longitudinal direction of the discharge lamp 11 immediately below the discharge lamp 11.

The polarizer 13Aa is a wire grid type polarizing element, and the number of the polarizers 13Aa is appropriately selected in accordance with the size of a region where the polarized light is irradiated. Further, each of the polarizers 13Aa is disposed such that the transmission axes are oriented in the same direction.

The polarizing subunit 13B also has the same configuration as the polarizing subunit 13A.

However, in the case of the two-lamp method in which the light-irradiating portions are arranged in two stages, the polarizer 13Ba of the polarizing sub-unit 13B is as shown in Fig. 4, and the joint between the polarizer 13Aa and the polarizer 13Ba is In a direction in which the conveyance direction (X direction) of the workpiece W does not overlap, the position is shifted and arranged in a direction orthogonal to the conveyance direction (Y direction). Thereby, the light-irradiating portions 10A and 10B can illuminate the polarized light with a uniform energy distribution.

Referring back to FIG. 1 , the conveyance unit 20 includes a flat workpiece stage 21 that sucks and holds the workpiece W by vacuum suction or the like, two guides 22 that extend in the moving direction of the workpiece stage 21 , and, for example, The electromagnet 23 constituting the moving mechanism of the workpiece stage 21.

Here, as the aforementioned moving mechanism, for example, a linear motor platform is employed. The linear motor platform is such that the moving body (workpiece table) is floated on a flat platen of a salient pole of a ferromagnetic body by a disk, and a magnetic force is applied to the moving body, and the moving body and the platen are moved. A mechanism that changes the magnetic force between the salient poles, thereby moving the moving body (workpiece table).

The workpiece stage 21 is disposed such that the direction of one side thereof faces the direction of movement of the stage (X direction), and is supported by the guide 22 to compensate for the straightness.

In the present specification, the moving direction of the workpiece stage 21 is the X direction. The horizontal direction perpendicular to the X direction is the Y direction, and the vertical direction is the Z direction. Further, the workpiece W has a rectangular shape and is held on the workpiece stage 21 in a direction in which one side faces the X direction and the other side faces the Y direction.

The movement path of the workpiece stage 21 is designed to pass right below the light irradiation portions 10A and 10B. Then, the conveying unit 20 is configured to convey the irradiation position of the polarized light caused by the workpiece W to the light irradiation units 10A and 10B, and to constitute the irradiation position. In the process of passing therethrough, the photoalignment film of the workpiece W is subjected to photoalignment processing.

Further, the polarized light irradiation device 100 includes a polarization measuring device 30. The polarization measuring device 30 includes a polarization axis detector 31, an X-direction conveying unit 32 for transporting the polarization axis detector 31 in the X direction along the guide 22, and a transfer mechanism for transporting the polarization axis detector 31 in the Y direction. The Y direction conveying unit 33. Further, the polarization measuring device 30 includes a control unit 34 and a monitor 35 which will be described later, in addition to the polarization axis detector 31, the X-direction transport unit 32, and the Y-direction transport unit 33.

The polarization axis detector 31 detects the polarization axis of the polarization ray (the axis of the polarization ray of the light irradiation surface) irradiated from the light irradiation sections 10A and 10B.

The X-direction conveying unit 32 is a moving mechanism that moves the polarization axis detector 31 in the X direction, and has the same structure as the above-described conveying unit 20, for example. That is, the moving path of the polarization axis detector 31 is designed to pass right below the light irradiation portions 10A and 10B. The X-direction transport unit 32 is in the X direction, and transports the polarization axis detector 31 to the irradiation position of the polarized light caused by the light-irradiating portions 10A and 10B.

The Y-direction conveying unit 33 is a moving mechanism that moves the polarization axis detector 31 in the Y direction. In the Y-direction transport unit 33, the polarization axis detector 31 is placed in the Y direction (the polarizers of the polarized sub-units 13A and 13B) in a state where the polarization axis detector 31 is located at the irradiation position of the polarized light rays by the light-irradiating portions 10A and 10B. The direction of the arrangement) moves.

In the present embodiment, the position of the polarization axis (hereinafter also referred to as "polarization measurement position") is directly below the polarizers of the polarizing subunits 13A and 13B (the center position of each polarizer), and the polarized light is polarized. The axis detector 31 measures the polarization axis at each polarization measurement position.

Hereinafter, the specific structure of the polarization axis detector 31 will be described with reference to FIGS. 5 and 6 .

The polarization axis detector 31 includes a first polarization ray detecting unit 311 and a second polarization ray detecting unit 312.

The first polarized light detecting unit 311 includes a detecting polarizer for detecting a polarization axis (hereinafter also referred to as "photodetector") 311a, and a first illuminance for detecting a polarized light passing through the detecting polarizer 311a. Detector 311b. The first illuminance sensor 311b includes a light receiving unit 311c (FIG. 6) that receives the polarized light that has passed through the detecting polarizer 311a. The light receiving unit 311c is fixed to the housing of the polarization axis detector 31 by the supporting member 311d.

FIG. 7 is a schematic view showing the configuration of the first polarized light detecting portion 311. In FIG. 7, the structure in which the first polarized light detecting unit 311 detects the state of the polarized light irradiated from the light irradiating unit 10A is disclosed.

As shown in Fig. 7, the light from the discharge lamp 11 of the light irradiation portion 10A (The emitted light L1) is linearly polarized by the polarizing subunit 13A, and the polarized light L2 is incident on the detecting polarizer 311a. In this case, the light receiving unit 311c receives the light passing through the detecting polarizer 311a as the detecting light L3.

The detecting polarizer 311a is, for example, a wire grid type polarizing element. Further, the detecting polarizer 311a may be any polarizer as long as it is a linear polarizer.

Further, the detecting polarizer 311a has a normal direction S as a rotation axis, and can be configured to be freely rotatable within a detection measurement range of 180° or more. The rotation of the detecting polarizer 311a is defined by the rotation angle θ from the preset reference position P0.

When the rotation angle θ of the detecting polarizer 311a is an angle at which the direction of the transmission axis T1 of the polarizer 13Aa of the polarizing sub-unit 13A coincides with the direction of the transmission axis T2 of the detecting polarizer 311a, the light received by the light receiving portion 311c is received. The illuminance is the biggest. Further, when the rotation angle θ of the detecting polarizer 311a is an angle perpendicular to the transmission axis T1, the illuminance of the light received by the light receiving unit 311c is minimized.

In other words, the illuminance of the light received by the light receiving unit 311c periodically changes in accordance with the rotation angle of the detecting polarizer 311a. Therefore, by monitoring the illuminance of the light received by the light receiving unit 311c while rotating the detecting polarizer 311a, the polarization axis angle of the polarized light irradiated from the light irradiation units 10A and 10B can be measured.

In order to rotate the detecting polarizer 311a, the first polarized light detecting unit 311 is provided with a detecting polarizer 311a. Rotating rotating mechanism. This rotation mechanism includes, for example, a rotary actuator 311e shown in FIGS. 5 and 6 and a rotary 311f fixed to the rotary actuator 311e.

The rotary actuator 311e is driven and controlled by a control unit 34 which will be described later. The detecting polarizer 311a is fixed to the rotor 311f, and the control unit 34 drives and controls the rotation actuator 311e to rotate the rotor 311f, thereby rotating the detecting polarizer 311a. Thereby, the detecting polarizer 311a and the first illuminance sensor 311b (light receiving portion 311c) are relatively rotated.

Further, as shown in FIG. 6, the first illuminance sensor 311b has an opening 311g that restricts incident light to the light receiving portion 311c. The polarizing sub-units 13A and 13B that are combined with the light-irradiating portions 10A and 10B are also configured to generate polarized light by obliquely incident light, and the polarized light due to the obliquely incident components is incident. The polarized light having an angle of, for example, a range of 0° to 65° is incident on the shape of the light receiving unit 311c.

Further, the first polarized light detecting unit 311 includes a cooling mechanism for cooling the first illuminance sensor 311b. This cooling mechanism is, for example, an air cooling system, and includes a cold air supply unit 311h that draws cooling from the outside.

Furthermore, the cooling mechanism can also be caused by water cooling. However, in view of the influence of damage to the water-cooled valve, air cooling is preferred.

Further, the second polarized light detecting unit 312 includes the detecting polarizer 311a in the first polarized light detecting unit 311 and the rotating mechanism for rotating the detecting polarizer 311a. The polarized light detecting unit 311 has the same structure.

In other words, as shown in FIGS. 5 and 6, the second polarized light detecting unit 312 includes a second illuminance sensor 312a that directly enters the polarized light rays from the light irradiation units 10A and 10B and detects the illuminance of the polarized light. The second illuminance sensor 312a includes a light receiving unit 312b that directly receives the polarized light from the light irradiation units 10A and 10B (FIG. 6).

The second illuminance sensor 312a is supported by the support member 312c such that the height position of the light receiving portion 312b is equal to the height position of the light receiving portion 311c of the first illuminance sensor 311b. The support member 312c is fixed to the frame of the polarized light detector 31.

Further, as shown in FIG. 6, the second illuminance sensor 312a has an opening 312d that restricts incident light to the light receiving portion 312b. The opening 312d is formed in the same manner as the above-described opening 311f, and is a polarized ray having an incident angle of, for example, 0° to 65°, and is incident on the light receiving unit 312b.

Further, the second polarized light detecting unit 312 includes a cooling mechanism for cooling the second illuminance sensor 312a. This cooling mechanism is, for example, an air cooling system, and includes a cold air supply unit 312e that draws cooling from the outside.

Furthermore, the cooling mechanism can also be caused by water cooling. However, in view of the influence of damage to the water-cooled valve, air cooling is preferred.

It is preferable that the second illuminance sensor 312a has a sensitivity in the same wavelength region as the first illuminance sensor 311b. However, as long as the radiation of the discharge lamp 11 can be detected at the same time, it is also possible to have sensitivity in different wavelength regions.

Specifically, it is preferable that the first illuminance sensor 311b and the second illuminance sensor 312a have sensitivity in a wavelength region of, for example, 200 nm to 400 nm. More specifically, the illuminance of the first illuminance sensor 311b and the second illuminance sensor 312a, for example, 254 nm, 313 nm, and 365 nm is easily measured.

Further, the light receiving portion 311c of the first illuminance sensor 311b and the light receiving portion 312b of the second illuminance sensor 312a are arranged side by side in the tube axis direction (longitudinal direction) of the discharge lamp 11. The tube axis direction of the discharge lamp 11 is the same direction as the Y direction of the moving polarization axis detector 31.

This is because the illuminance that is emitted from the discharge lamp 11 changes greatly in the direction of the tube diameter, and the illuminance changes little in the tube axis direction. By arranging the light receiving unit 311c and the light receiving unit 312b along the tube axis direction (longitudinal direction) of the discharge lamp 11, the light detected by the first illuminance sensor 311b and the second illuminance sensor 312a can be reduced. The difference in illuminance.

In addition, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 respectively have a cooling mechanism for cooling the light receiving unit. However, the heat radiated from the discharge lamp 11 is also transmitted through the Y direction. The portion 32 and the like are transmitted from the lower side of the polarization axis detecting unit 31. Therefore, a heat insulating member may be provided at the bottom of the frame of the polarizing axis detecting portion 31, or the rotating mechanism may be suspended.

Next, the control unit 34 constituting the polarization measuring device 30 will be described.

FIG. 8 is a block diagram showing the configuration of the polarization measuring device 30.

As described above, the polarization measuring device 30 is provided with a polarization axis detector 31. The X-direction transport unit 32, the Y-direction transport unit 33, the control unit 34, and the monitor 35.

The control unit 34 includes a rotation sub-control unit 34a, an input signal conversion unit 34b, a polarization characteristic calculation unit 34c, an image display unit 34d, and a conveyance control unit 34e.

The rotation sub-control unit 34a outputs a drive command for driving the control rotary actuator 311d to the first polarization ray detecting unit 311. In the present embodiment, in each of the polarization measurement positions, the photodetector 311a is rotated into a predetermined number of angles within a predetermined rotation angle range θ 1 ≦ θ ≦ θ 2 , and the first illuminance sensor is used in each specified angle. 311b measures the polarized light. The rotation angle range is an angle (setting reference value θ a ) of the photodetector 311 a which is the minimum illuminance of the polarized light detected by the first illuminance sensor 311 b , and is set, for example, within a range of ±20°.

For example, when the set reference value θ a is set to 120°, the range of the rotation angle is 100° ≦ θ ≦ 140°.

Further, in the present embodiment, in the range of the rotation angle, for example, in addition to θ = θ a , the angular position of the polarized ray is measured every 10° intervals. That is, when the rotation angle range is 100 ° ≦ θ ≦ 140 °, the polarized light is measured at θ = θ 1 = 100 °, θ = 1010 °, θ = 130 °, and θ = θ 2 = 140 °. The rotation sub-control unit 34a outputs a drive command to the rotary actuator 311d in order to set the photodetector 311a to any of the four angular positions.

The input signal conversion unit 34b inputs the first illuminance sensor The detected illuminance value (illuminance count value) Cd of the illuminance information detected by 311b and the reference illuminance value (illuminance count value) Cr of the illuminance information detected by the second illuminance sensor 312a are amplified, and the detection signals are amplified and output to The polarization characteristic calculation unit 34c.

Here, the first illuminance sensor 311b and the second illuminance sensor 312a detect the illuminant of the received light at the same timing, and the input signal conversion unit 34b receives the two detection signals simultaneously input by the two sensors. The way it is structured.

The polarization characteristic calculation unit 34c calculates the polarization characteristics of the polarization ray irradiated from the light irradiation units 10A and 10B based on the illuminance information input from the input signal conversion unit 34b. In the present embodiment, the polarization characteristic calculation unit 34c measures the polarization axis angle and the extinction ratio as the polarization characteristics.

The image display unit 34d outputs the polarization characteristics calculated by the polarization characteristic calculation unit 34c to the monitor 35.

The conveyance control unit 34e drives and controls the X-direction conveyance unit 32 and the Y-direction conveyance unit 33, moves the polarization axis detector 31 in the XY direction, and moves to the predetermined polarization measurement position.

The control unit 34 and the monitor 35 are provided away from the polarization axis detector 31, the X-direction transport unit 32, and the direction transport unit 33 so as not to be affected by the ultraviolet light emitted from the discharge lamp 11 (mainly due to heat). s position. The control unit 34 transmits the output of the drive command to the polarization axis detector 31 and the acquisition of the detection signal from the polarization axis detector 31 through a cable (not shown).

FIG. 9 is a flowchart showing the procedure of the polarization measurement process performed by the control unit 34. This polarization measurement process reveals the order of measurement of the polarized light at the predetermined polarization measurement position.

First, in step S1, the control unit 34 outputs a drive command to the rotary actuator 311d from the rotation sub-control unit 34a to rotate the photodetector 311a to a predetermined angle. Here, the initial value of the specified angle is set to θ=θ 1 .

Next, in step S2, the control unit 34 acquires the detected illuminance value Cd from the first illuminance sensor 311b, and acquires the reference illuminance value Cr from the second illuminance sensor 312a, and the process proceeds to step S3.

In step S3, the corrected illuminance value Cr is calculated by dividing the reference illuminance value Cr by the detected illuminance value Cd obtained in the above step S2 (Cc = Cr / Cd). The corrected illuminance value Cc is used to correct the error caused by the illuminance variation per hour of the light from the discharge lamp 11 included in the detected illuminance value Cd with reference to the illuminance value Cr.

Next, in step S4, the control unit 34 determines whether or not the illuminance measurement is completed in all of the angular positions set in advance. Then, when it is determined that the measurement is not completed, the designated angle is reset and the process proceeds to the above-described step S1. When it is determined that the illuminance measurement has been completed, the process proceeds to step S5.

In step S5, the control unit 34 calculates the polarization axis of the polarization ray based on the corrected illuminance value Cc of each angular position calculated in the above-described step S3.

In the present embodiment, curve fitting is performed based on each corrected illuminance value Cc, and the rotation angle indicating the photodetector 311a is obtained. The polarization ray angle characteristic (hereinafter, simply referred to as "angle characteristic") of the relationship of the corrected illuminance value Cc. The polarization ray angle characteristic indicates a characteristic in which the illuminance of the polarized ray of the photodetector 311a when the photodetector 311a is rotated is periodically changed, and the error due to the illuminance variation described above is corrected. Then, the polarization axis angle is calculated from the obtained angle characteristics.

Here, as a fitting function, for example, a function of Acos ² (θ+B)+C is used. Furthermore, other functions can be used as a fitting function.

Fig. 10 is a view showing an example of the aforementioned angular characteristics. Here, the angular position of the polarized light is measured, and is set to four places of θ=120°±10° and θ=120°±20°.

In FIG. 10, the vertical axis is the monitor illuminance count value [%], and the horizontal axis is the rotation angle θ [degrees] of the photodetector 311a. The dotted line in the figure is the reference illuminance value Cr, and the points a to d are plotted against the corrected illuminance value Cc calculated in each angular position. Further, the curve F is based on the four measurement points a to d, and is fitted by the least square method and the Newton method, and the curve obtained by obtaining the constants A, B, and C is equivalent to the aforementioned polarized ray angle. characteristic.

In the angle characteristic F, the angle at which the monitor illuminance count value becomes the smallest is the rotation angle of the photodetector 311a whose transmission axis of the photodetector 311a is substantially orthogonal to the transmission axis of the polarizer 13Aa (or 13Ba). Further, the angle at which the monitor illuminance count value becomes the smallest minus 90° is the angle at which the monitor illuminance count value becomes maximum, that is, the transmission axis of the photodetector 311a and the transmission axis of the polarizer 13Aa (or 13Ba) are actually One The angle of rotation of the photodetector 311a is obtained.

Here, the angle at which the monitor illuminance count value becomes the smallest is the parameter B obtained by the above-described curve fitting, and the set reference value θ a includes the predetermined offset θ b angle (B=θ a+θ b ). Therefore, the control unit 34 outputs the actual polarization axis angle (the direction of the transmission axes of the polarizers 13Aa and 13Ba) based on the angle (θ a + θ b ).

The rotation angle of the photodetector 311a is defined by the angle θ with respect to the reference position P0 as described above. Therefore, when the polarization axis angle is defined by the angle with respect to the reference position P0 in the same manner as the photodetector 311a, the control unit 34 outputs the angle from the angle (θ a + θ b) by 90° as the actual polarization axis angle. . Further, when the polarization axis angle is defined by the angle of the position shifted by 90 from the reference position P0, the control unit 34 directly outputs the angle (θ a + θ b) as the actual polarization axis angle.

Next, in step S6, the control unit 34 rotates the photodetector 311a until the angle (θ a + θ b) at which the monitor illuminance count value calculated in the above-described step S5 is the smallest, and the process proceeds to step S7.

In step S7, the control unit 34 acquires the detected illuminance value Cd (measurement point e in Fig. 10) from the first illuminance sensor 311b, and sets this as the minimum illuminance of the polarized ray, and the process proceeds to step S8.

In step S8, the control unit 34 rotates the photodetector 311a until the angle at which the monitor illuminance count value calculated in the above-described step S5 is the smallest (θ a + θ b - 90°), and the process proceeds to step S9.

In step S9, the control unit 34 acquires the detected illuminance value Cd (measurement point f of Fig. 10) from the first illuminance sensor 311b, and this The maximum illuminance of the polarized light is set, and the process proceeds to step S10.

In step S10, the control unit 34 calculates the extinction ratio based on the ratio of the minimum illuminance obtained in the above-described step S7 to the maximum illuminance obtained in the above step S9 (maximum illuminance/minimum illuminance).

In step S11, the control unit 34 outputs the polarization axis angle calculated in the above-described step S5 and the extinction ratio calculated in the above-described step S10 to the monitor 35 from the image display unit 34d. Thereby, the measurement result of the polarization characteristic is displayed on the monitor 35.

Further, steps S1 to S4 of FIG. 9 correspond to the rotation control unit, and steps S5 to S10 correspond to the polarization characteristic calculation unit. Further, step S5 corresponds to the polarization axis angle calculation unit, and steps S6 to S10 correspond to the extinction ratio calculation unit.

Next, the operation and effects of the present embodiment will be described.

First, the control unit 34 drives and controls the X-direction transport unit 32 and the Y-direction transport unit 33, and arranges the polarization ray detector 31 on the far-end polarizer 13Aa located in the Y direction among the plurality of polarizers 13Aa of the polarization subunit 13A. Directly below. In this way, the control unit 34 arranges the polarized light detector 31 in the irradiation region of the polarized light of the polarizer 31Aa that is subjected to the measurement of the polarization characteristics.

In the case where the reference value θ a = 120° is set, when the photodetector 311a is θ = 120°, the illuminance of the polarized light detected by the first illuminance sensor 311b should be minimized. Therefore, first, the control unit 34 drives and controls the rotary actuator 311d to rotate the photodetector 311a so that θ = θ a - 20 ° = 100°.

Then, in this state, the illuminance of the polarized light is simultaneously measured by the first illuminance sensor 311b and the second illuminance sensor 312a, and the control unit 34 acquires the illuminance information measured by the two sensors. In other words, the control unit 34 acquires the detected illuminance value Cd of the illuminance information of the polarized light passing through the photodetector 311a from the first illuminance sensor 311b, and acquires the polarized light that has not passed through the photodetector 311a from the second illuminance sensor 312a. The reference illuminance value Cr of the illuminance information of the light.

Next, the control unit 34 drives and controls the rotary actuator 311d to rotate the photodetector 311a so that the position becomes θ=100° to θ=110°. Then, in its position, the control unit 34 acquires the detected illuminance value Cd and the reference illuminance value Cr measured by the first illuminance sensor 311b and the second illuminance sensor 312a.

Thereafter, the control unit 34 rotates the photodetectors 311a to θ=130° and θ=140°, respectively, and acquires the detected illuminance values Cd measured by the first illuminance sensor 311b and the second illuminance sensor 312a in the same manner. Refer to the illuminance value Cr.

Then, the control unit 34 calculates the angle characteristic shown in FIG. 10 based on the detected illuminance value Cd and the reference illuminance value Cr obtained at the respective angular positions.

Since the detected illuminance value Cd is the illuminance value of the polarized light passing through the photodetector 311a, the value fluctuates depending on the angle formed by the transmission axis of the polarizer 13Aa and the transmission axis of the photodetector 311a. Therefore, by monitoring the fluctuation of the detected illuminance value Cd while changing the rotation angle θ of the photodetector 311a, the rotation angle indicating the photodetector 311a and the photodetection can be calculated. The angular characteristic of the relationship of the illuminance information of the polarized light of 311a.

However, the discharge lamp 11 of the light source changes the amount of light momentarily due to the shaking of the arc, and the amount of light emitted from the discharge lamp 11 changes between the rotation angle θ of the photodetector 311a.

Therefore, when the angle characteristic is calculated by directly using the detected illuminance value Cd regardless of the shaking of the arc of the discharge lamp, the angular characteristic including the error caused by the variation of the illuminance per hour of the light irradiated from the discharge lamp 11 is calculated, and the polarization measurement is performed. The accuracy will be significantly reduced.

Therefore, in the present embodiment, the first illuminance sensor 311b measures the illuminance of the polarized light from the light-irradiating portion of the photodetector 311a, and in synchronization with this, the second illuminance sensor 312a determines that the photodetector 311a does not pass. The illuminance of the polarized light from the light-irradiating portion. That is, by observing the shaking of the same arc with both, the reference illuminance value Cr obtained by the second illuminance sensor 312a is used as the reference value of the detected illuminance value Cd obtained by the first illuminance sensor 311b. .

The control unit 34 corrects the arc included in the detected illuminance value Cd by dividing the detected illuminance value Cd obtained from the first illuminance sensor 311b by the reference illuminance value Cr obtained from the second illuminance sensor 312a. The error caused by the fluctuation of the illuminance. Then, using the corrected illuminance value (corrected illuminance value Cc) as a reference, the angle characteristic F as shown in FIG. 10 is calculated using the curve fitting method.

As described above, the detected illuminance value Cd and the reference illuminance value of the Cr-based arc are the same. Therefore, by using the corrected illuminance value Cc, even if the arc changes during the rotation of the photodetector 311a, The angle characteristics can be calculated with high precision.

When the control unit 34 calculates the angle characteristic F as shown in FIG. 10, the angle of the polarization axis is calculated based on the angle characteristic F. Specifically, based on the angle characteristic F, the illuminance of the polarized ray passing through the photodetector 311a is specified as the rotation angle (θ a + θ b) of the photodetector 311a which is the smallest, and based on this, the actual polarization axis angle is output. .

Next, the control unit 34 calculates the extinction ratio of the polarized light using the angle characteristic F. First, the control unit 34 drives and controls the rotary actuator 311d to detect the minimum illuminance of the polarized ray, and rotates the photodetector 311a to θ = (θ a + θ b). In this state, the control unit 34 acquires the detected illuminance value Cd (measurement point e of FIG. 10) of the minimum illuminance value from the first illuminance sensor 311b.

Next, the control unit 34 drives and controls the rotary actuator 311d to detect the maximum illuminance of the polarized ray, and rotates the photodetector 311a to θ = (θ a + θ b - 90 °). In this state, the control unit 34 acquires the detected illuminance value Cd of the maximum illuminance value from the first illuminance sensor 311b (measurement point f in Fig. 10).

Then, the control unit 34 calculates the extinction ratio based on the ratio of the minimum illuminance value to the maximum illuminance value (maximum illuminance value/minimum illuminance value).

From the above, the polarization characteristics of the polarized light rays passing through the polarizer 13Aa located at the farthest end in the Y direction among the plurality of polarizers 13Aa of the polarizing subunit 13A can be obtained. Next, the control unit 34 drives and controls the Y-direction transport unit 33, and arranges the polarized light detector 31 directly below the polarizer 13Aa adjacent to the polarizer 13Aa that has previously measured the polarization characteristics. square. In this manner, the measurement target of the polarization characteristic is sequentially switched, and the polarization characteristics are measured.

When the measurement of the polarization characteristics of all the polarizers 13Aa of the polarizer unit 13A is completed, the control unit 34 drives and controls the X-direction transport unit 33 and the Y-direction transport unit 33, and the polarized light detector 31 is disposed in the polarization sub-unit 13B. The sub- 13Ba is located directly below the most distal polarizer 13Ba in the Y direction. Then, similarly to the state of the polarizing subunit 13A, the polarization characteristics are measured for each of the polarizers 13Ba.

In the fixed point, as described above, the detected illuminance value Cd and the reference illuminance value Cr are detected, and the result of measuring the polarization axis angle based on the reference illuminance value Cr corrected based on the detected illuminance value Cd is disclosed in FIG. . Here, the vertical axis of FIG. 11 is the polarization axis angle, and the horizontal axis is the number of times of measurement of the polarization axis angle. As shown by the experimental result α, in the present embodiment, the measured polarization axis angle hardly deviated, and the standard deviation 3 σ was 0.004. That is, the measured polarization axis angle is 99.7% in a range in which the deviation of ±0.004° is extremely small.

As a comparative example, as in the present embodiment, the correction by the reference illuminance value Cr is not performed, and the polarization axis angle is measured using only the detected illuminance value Cd. The result of β in Fig. 11 reveals the result.

As shown by the experimental result β, the measurement results may vary in the comparative example, and a strong protrusion value may be scattered in some cases. In this case, since the photodetector 311a is rotated, the arcing of the arc between the polarized rays is measured at four different angles, and the polarization axis angle cannot be stably measured. Thus, it can be visually understood that the measurement results are uneven due to the shaking of the arc.

Further, the measurement results of the comparative examples were measured, and as a result, the standard deviation 3 σ of the measured polarization axis angle was 0.035. That is, the measured polarization axis angle has a deviation of ±0.035°.

In the polarized light irradiation device 100, it is preferable to adjust the polarization axis angle to within ±0.05° from the viewpoint of the required accuracy of the optical alignment process. That is, the accuracy of the polarization measurement is preferably ±0.01°. However, in the foregoing comparative example, the required accuracy of the polarization measurement cannot be satisfied.

In the present embodiment, in addition to the first polarized light detecting unit 311 having the photodetector, the second polarized light detecting unit 312 that directly detects the polarized light without transmitting the photodetector includes the first polarized light detecting unit 311 and the second polarized light. The light detecting unit 312 simultaneously detects the same polarized light.

Therefore, the illuminance information detected by the second polarized light detecting unit 312 can be used as the reference illuminance information of the polarized light to correct the illuminance information detected by the first polarized light detecting unit 311 due to the discharge. The error caused by the variation of the illuminance per hour of the arc of the lamp 11 is shaken. Therefore, the angular characteristic indicating the periodic change of the illuminance of the detected ray when the photodetector 311a of the first polarized light detecting unit 311 is rotated can be accurately calculated, and the polarization axis angle and the extinction ratio can be accurately calculated.

Further, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 are arranged side by side in the longitudinal direction of the discharge lamp 11. In this way, since the illuminance of the discharge lamp 11 is arranged in a direction in which the fluctuation of the illuminance is small, the dependence of each place can be reduced, and the measurement result with reliability can be obtained.

In particular, when a lamp of a double lamp type or more is applied as a light source, When the polarized light detecting unit 311 and the second polarized light detecting unit 312 are arranged in parallel with each other in the direction of the diameter of the tube, the light emitted from the tube adjacent to the measuring tube is easily affected, and reliability cannot be obtained. The result of the measurement. In the present embodiment, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 are arranged side by side in the longitudinal direction of the discharge lamp 11, and therefore, even in the case of using a lamp of a double lamp type or more as a light source, In the meantime, reliable measurement results can also be obtained.

Further, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 are used in a state in which they are arranged side by side directly below the discharge lamp 11, and the conditions regarding heat are strict. For example, when the holding member holding the photodetector 311a is formed of aluminum or the like, the holding member thermally expands due to the influence of ultraviolet light (heat) radiated from the discharge lamp 11, and the relative position of the photodetector 311a and the light receiving portion 311c deviates. There is a change in the illuminance of the light detected by the light receiving unit 311c.

In the present embodiment, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 are respectively provided with cooling means for cooling the first illuminance sensor 311b and the second illuminance sensor 312a, which can stably detect Polarized light.

Further, when the illuminance information (detected illuminance value Cd) detected by the first polarized light detecting unit 311 is corrected based on the illuminance information (refer to the illuminance value Cr) detected by the second polarized light detecting unit 312, the illuminance information (detected illuminance value Cd) detected by the first polarized light detecting unit 311 is used. The detected illuminance value Cd is divided by the reference illuminance value Cr, and the corrected illuminance value Cc for correcting the error due to the fluctuation of the illuminance per hour caused by the arcing of the arc of the discharge lamp 11 is calculated. So, the use is relatively simple The method to correct the aforementioned error.

Further, the measurement point of the polarized light is set within a predetermined rotation angle range of the set reference value θ a set so as to minimize the illuminance of the detected ray when the photodetector 311 a of the first polarized light detecting unit 311 is rotated. 4 places. Then, based on the illuminance information of the four measurement points, the angular characteristic indicating the periodic change of the illuminance of the detection ray when the photodetector 311a of the first polarization ray detecting unit 311 is rotated is calculated.

In this way, the illuminance information measured in the vicinity of the angle at which the illuminance of the detected light is minimized is used for the calculation of the angle characteristic, so that the angle characteristic for suppressing the influence of the noise component can be calculated.

Further, since the second polarized light detecting unit that directly detects the polarized light from the light irradiation units 10A and 10B is provided, the illuminance of the polarized light can be measured while measuring the polarization axis angle and the extinction ratio of the polarized light. In this way, the measurement of the polarization characteristics of the polarized light and the measurement of the illuminance of the polarized light can be simultaneously performed, and high efficiency can be obtained.

As described above, in the present embodiment, even in the case of using a light source having an illuminance variation per hour, the polarization axis angle and the extinction ratio of the polarized light can be easily and accurately measured without being affected by the illuminance fluctuation. .

Therefore, it is possible to appropriately determine whether or not the polarization axis of the polarized light irradiated from the light irradiation portion is a desired polarization axis or the like. Then, when the desired polarization axis is not obtained, in order to obtain a desired polarization axis, it is possible to perform a process of adjusting the arrangement angle of the polarizers of the light irradiation portion, etc., and to perform an appropriate light alignment. Reason.

(Modification)

In the above-described embodiment, the case where the corrected illuminance value Cc is calculated by dividing the detected illuminance value Cd by the reference illuminance value Cr is described. However, for example, other methods may be applied.

Hereinafter, as another method, a method of correcting using the subtraction and the average value will be described.

First, in the total of four places of θ=θ a±20° and θ=θ a±10°, the first polarized light detecting unit 311 and the second polarized light detecting unit 312 measure the detected illuminance value Cd and the reference illuminance value, respectively. Cr. Here, the detected illuminance values Cd measured at the respective designated angles are Cd1, Cd2, Cd3, and Cd4, and the reference illuminance values Cr measured at the respective designated angles are set to Cr1, Cr2, Cr3, and Cr4.

Then, the control unit 34 calculates the average value Cra of the reference illuminance values Cr1 to Cr4 measured at the respective designated angles, and calculates the corrected illuminance value Cc from the detected illuminance value Cdn by subtracting the average value Cra from the reference illuminance value Crn. The value of the difference. That is, the corrected illuminance value Cc is Cc1=Cd1-(Cra-Cr1), Cc2=Cd2-(Cra-Cr2), Cc3=Cd3-(Cra-Cr3), Cc4=Cd4-(Cra-Cr4).

The subsequent processing is the same as the processing after step S5 of Fig. 9 . That is, the control unit 34 uses the corrected illuminance values Cc1 to Cc4 as a reference, and performs curve fitting by the least squares method and the Newton method to obtain a constant A of the fitting function Acos ² (θ+B)+C, B, C. The control unit 34 calculates the polarization ray angle characteristics in this way.

In this case, the illuminance value of the error due to the fluctuation of the illuminance per hour caused by the arc of the discharge lamp 11 included in the detected illuminance value Cd can be corrected, and the polarization ray angle characteristic can be obtained, and the polarization ray angle characteristic can be accurately obtained. The polarization axis angle and the extinction ratio were measured.

Furthermore, in the above-described embodiment, the illuminance is measured by the first polarized light detecting unit 311 in the case where θ = θ a ± 20° and θ = θ a ± 10° are respectively used four times in total, and the illuminance is measured. However, the number of measurements can be appropriately set in accordance with the allowable measurement time. The calculation by the least square method can be performed even if the measurement point is three, so the number of measurements can be set to three times. When the measurement is performed at four places, the angle characteristics and the like are calculated for individual use by using four combinations of three places, and the accuracy of the measurement result may be improved. Further, of course, the number of measurements may be five or more.

Further, in the above-described embodiment, the case where the photodetector 311a is rotated every 10° during the illuminance measurement has been described. However, the interval angle may be appropriately set.

Furthermore, in the above-described embodiment, the state in which the polarization measurement position is set only at the center 1 of each of the polarizers 13Aa and 13Ba has been described. However, in consideration of the deviation of the polarization axis angle in one of the polarizers, It is also possible to set a plurality of polarization measurement positions for each polarizer. In this case, the final polarization characteristic may be calculated by weighting and averaging the measurement results of the respective polarization measurement positions.

Further, in the above embodiment, the polarization axis angle measured by the polarization measuring device 30 is used as a reference, and the polarizer 13Aa and the bias are provided. The mechanism in which the polarization axis angle of the photon 13Ba is the desired polarization axis angle, and the angle of the polarizer 13Aa and the polarizer 13Ba is automatically adjusted. Further, the angle adjustment of the polarizer 13Aa and the polarizer 13Ba may be performed manually by the operator.

Further, in the above-described embodiment, the case where the light receiving portion 311c of the first illuminance sensor 311b is fixed to the housing of the polarization axis detector 31 by the support member 311d will be described. However, the light receiving portion 311c is used as the light receiving portion 311c. A structure that can rotate together with the photodetector 311a is also possible. However, in order to stably measure the illuminance, as in the above-described embodiment, the light receiving portion 311c is fixed, and the photodetector 311a and the light receiving portion 311c are relatively rotated.

Further, in the above-described embodiment, the case where the discharge lamp 11 of the two-lamp type is applied as the light source has been described. However, as the single lamp method, the three-lamp method may be used.

Further, in the above-described embodiment, the state in which the liquid crystal panel forming the photoalignment film is used as the workpiece W will be described. However, for example, as the viewing angle compensation film, the long strip-shaped workpiece wound around the roller is also used. can.

311‧‧‧First Polarized Light Detection Department

311a‧‧‧Detecting polarizers

311b‧‧‧First illumination sensor

311e‧‧‧Rotary actuator

311f‧‧‧ Rotator

311h‧‧‧Air Supply Department

312‧‧‧Second Polarized Light Detection Department

312a‧‧‧Second illumination sensor

312c‧‧‧Support components

312e‧‧‧Air Supply Department

Claims (10)

A polarization axis detector is a polarization axis detector that detects a polarization axis of a polarized light that is irradiated from a light source, and is characterized in that the first polarization light detecting unit includes a rotatable detection polarization for detecting the polarization axis. a first illuminance sensor for detecting illuminance information of the polarized light from the light source passing through the detecting photon; and a second polarized light detecting portion having illuminance information for directly detecting the polarized light from the light source The second illuminance sensor is disposed side by side in the first polarized light detecting portion. The polarization axis detector according to claim 1, wherein the light source is a linear light source, and the first illuminance sensor and the second illuminance sensor extend along the linear light source. The direction is arranged side by side. A polarized light measuring device comprising: the polarizing axis detector according to the first or second aspect of the patent application; and the polarized light measuring unit based on the illuminance information detected by the polarizing axis detector. The polarized light measuring unit includes a rotation control unit that rotates the detecting polarizer into a plurality of designated angles; The illuminance information correction unit is configured to determine, according to the plurality of specified angles, the detected illuminance value of the illuminance information detected by the first illuminance sensor, and the detected illuminance value caused by the synchronization of the first illuminance sensor. Detecting, by using a reference illuminance value of the illuminance information detected by the second illuminance sensor, calculating an error caused by an hourly illuminance variation of the polarized ray irradiated from the light source included in the detected illuminance value The corrected illuminance value; and the polarization characteristic calculation unit calculates a polarization ray angle characteristic indicating a relationship between a rotation angle of the detection polarizer and a corrected illuminance value calculated by the illuminance information correction unit, and the polarization ray angle characteristic Based on the ray angle characteristic, the polarization characteristics of the polarized light from the light source are calculated. The illuminance measuring device according to the third aspect of the invention, wherein the illuminance information correcting unit divides the detected illuminance value detected by the first illuminance sensor by a value synchronized with the detected illuminance value. The corrected illuminance value is calculated by detecting the reference illuminance value detected by the second illuminance sensor. The illuminance measuring device according to the third aspect of the invention, wherein the illuminance information correcting unit subtracts the detected illuminance value detected by the first illuminance sensor from the plurality of specified angles The average value of each reference illuminance value detected by the second illuminance sensor and the difference between the reference illuminance values detected by the second illuminance sensor synchronized with the detection of the detected illuminance value, thereby calculating After the aforementioned correction Illumination value. The polarization measuring device according to any one of the third aspect, wherein the polarization characteristic calculation unit includes a polarization axis angle calculation unit that is specified based on the polarization ray angle characteristic. The illuminance of the polarized ray from the light source by the detecting polarizer is an extreme value of the rotation angle of the detecting polarizer, and the polarization axis angle of the polarized ray is calculated as the polarization characteristic in accordance with the specific rotation angle. . The polarization measuring device according to any one of the third aspect, wherein the polarization characteristic calculating unit includes an extinction ratio calculating unit that specifically passes the polarization ray angle characteristic as a reference. The maximum value and the minimum value of the illuminance of the polarized light from the light source of the detecting polarizer are calculated as the extinction ratio of the polarized light as the polarization characteristic according to the specific maximum value and the minimum value. A method for measuring a polarized light, which is a method for measuring a polarized light that is irradiated from a light source, and is characterized in that: a detection polarizer for detecting the polarization axis is used, rotated to a predetermined angle, and detected in each specified angle a step of detecting a detected illuminance value of the illuminance information of the polarized light from the light source by the polarizer; and synchronizing with the timing of detecting the illuminance information of the polarized light from the light source passing through the detecting polarizer, the direct detection does not pass the detection Reference illuminance of illuminance information of polarized light from the aforementioned light source using a polarizer The step of the value. The polarization measuring method according to the eighth aspect of the invention, further comprising: calculating, based on the detected illuminance value detected from the complex specified angle and the reference illuminance value, calculating a correction included in the detected illuminance value a step of correcting the illuminance value of the error caused by the variation of the illuminance per hour of the polarized light irradiated by the light source; and calculating the polarization ray angle characteristic indicating the relationship between the rotation angle of the detecting polarizer and the corrected illuminance value And a step of calculating a polarization characteristic of the polarized light from the light source based on the polarization ray angle characteristic. A polarized light irradiation device is a polarized light irradiation device that irradiates a polarizing ray to a aligning light to perform light alignment, and is characterized in that the light illuminating portion includes a linear light source and a direction in which the linear light source extends. And a polarization measuring device according to any one of the third to seventh aspects of the invention, wherein the polarized light measuring device is used for measuring the polarized light of the linear light source; The polarized light that is irradiated by the light irradiation unit.