KR102036235B1 - Polarization measuring process, polarization measuring apparatus, polarization measuring system and photo-alignment irradiation apparatus - Google Patents

Abstract

The subject of this invention is measuring the polarization characteristic of polarized light with high precision.
The detection side based on the amount of light I at each rotation angle θ obtained by detecting the light transmitted through the wire grid polarizer 16 and the detection side polarizer 33 while rotating the detection side polarizer 33. The change curve Q which shows the periodical change of the said light quantity I when the polarizer 33 rotates is calculated | required, and the polarized light F which permeate | transmitted the said wire grid polarizer 16 based on this change curve Q. When specifying the polarization characteristic of the range, the range W of the rotation angle θ including the rotation angle θ = θa which is one minimum point of the change curve Q, and the light amount I is equal to or less than a predetermined value The change curve Q is obtained based on the light amount I at the rotation angle θ included in the.

Description

POLARIZATION MEASURING PROCESS, POLARIZATION MEASURING APPARATUS, POLARIZATION MEASURING SYSTEM AND PHOTO-ALIGNMENT IRRADIATION APPARATUS}

The present invention relates to a measurement technique of polarized light.

Conventionally, the technique called photo-alignment which orientates by irradiating a polarizing light to an orientation film or an orientation layer (henceforth these are called a "photoalignment film") is known, and this photo-alignment is the liquid crystal which a liquid crystal display element of a liquid crystal display panel has It is widely applied to the orientation of an alignment film.

Generally, the irradiation apparatus used for optical alignment is equipped with a light source and a polarizer, and transmits the light of a light source to a polarizer, and obtains polarized light. In recent years, in order to photo-align a long band-shaped photo-alignment film, line-shaped polarized light is performed by arranging a some polarizer in the long-axis direction of a rod-shaped lamp using the rod-shaped lamp of the length equivalent to the width of a photo-alignment film as a light source. The irradiation apparatus to irradiate is known, the strip | belt-shaped photoalignment film is uniformly lighted by carrying out the width direction of the strip | belt-shaped photoalignment film in the direction which the irradiation area of the polarizing light of this irradiation apparatus extends, and conveying the said photoalignment film in the longitudinal direction. The technique to orientate is also proposed (for example, refer patent document 1).

As a factor of the polarized light which affects the quality of optical orientation, two of extinction ratio and the deviation of polarization axis distribution are known, and it is important that they are adjusted with high precision as an irradiation apparatus used for optical alignment. As a technique of measuring polarization characteristics, such as an extinction ratio and a polarization axis, various techniques are conventionally proposed (for example, refer patent document 2-patent document 4).

Japanese Patent Application Publication No. 2004-163881 Japanese Patent Application Publication No. 2004-226209 Japanese Patent Application Publication No. 2005-227019 Japanese Patent Application Publication No. 2007-127567

In order to obtain a high-quality liquid crystal aligning film using photo-alignment, it is necessary to irradiate the polarized light in which the extinction ratio is high and the polarization axis is adjusted with the precision which is within 0.1 degrees of error. In order to adjust the polarization axis to an accuracy of 0.1 ° or less, an error of 0.01 ° or less is required as a measurement accuracy. However, in an irradiation apparatus using a discharge lamp as a light source, variations (unstable) in the amount of light are caused due to variations in the lighting power of the discharge lamp. There is no technique that can measure the polarization characteristics of the polarized light with the accuracy that satisfies this requirement.

In the conventional method, since a variation occurs in the amount of light, it is necessary to increase the repeat accuracy by taking the same measurement over and over again and taking the average, thereby causing a problem that the measurement requires time.

As a technique of measuring a polarization axis, the technique of measuring a polarization axis for every polarizer is proposed. This can use the conventional polarization measurement technique. However, in the above-described method, since the angle of light introduction into the polarization measuring instrument is shallow, the polarization characteristic of the light actually irradiated on the optical alignment film on the stage at the position where the polarized light passing through the plurality of polarizers is irradiated is overlapped. Does not.

This invention is made | formed in view of the above-mentioned situation, and an object of this invention is to provide the polarization measuring method, polarization measuring device, polarization measuring system, and photo-alignment irradiation apparatus which can measure the polarization characteristic of polarized light with high precision.

In order to achieve the above object, the present invention provides the second polarizer is based on the amount of light at each rotation angle obtained by detecting the light transmitted through the first polarizer and the second polarizer in order while rotating the second polarizer. A first step of obtaining a change curve representing a periodic change in the amount of light when rotated; and a second step of specifying a polarization characteristic of polarized light transmitted through the first polarizer based on the change curve obtained in the first step. In the first step, the change is based on the amount of light at the rotation angle that includes one minimum point of the change curve and is included in a range of the rotation angle at which the light amount becomes equal to or less than a predetermined value. It provides a polarization measurement method characterized by obtaining a curve.

Moreover, this invention is the said polarization measurement method WHEREIN: The said light quantity in the said rotation angle is included in the range of the said rotation angle which includes one minimum point different from the said 1st step, and the said light quantity becomes below a predetermined value. A third step of obtaining the change curve based on the second step; a fourth step of specifying the polarization characteristic of the polarized light transmitted through the first polarizer based on the change curve obtained in the third step; and the second step and the fourth step. The fifth step of specifying the polarization characteristic of the polarized light which permeate | transmitted the said 1st polarizer based on the average of the said polarization characteristic specified in each of the steps is characterized by the above-mentioned.

Moreover, this invention is the said polarization measuring method WHEREIN: The said predetermined value is characterized by the light quantity of about 20% of the maximum value of the said light quantity.

Furthermore, in the said polarization measuring method, this invention WHEREIN: The polarization axis of the polarized light which permeate | transmitted the said 1st polarizer based on the rotation angle corresponding to the maximum value of the light quantity which the said change curve shows, and / or the said change curve is The first polarizer based on the amount of light measured when the second polarizer rotates at each of a rotation angle of the polarization axis of the polarized light specified based on the maximum and minimum values indicated or the change curve and a rotation angle orthogonal to the polarization axis. It is characterized by specifying the extinction ratio of the polarized light transmitted through.

Further, in order to achieve the above object, the present invention is based on the amount of light at each rotation angle obtained by detecting the light transmitted through the first polarizer and the second polarizer in order while rotating the second polarizer, the second polarizer A change curve calculating means for obtaining a change curve indicating a periodic change in the amount of light when the light is rotated, and a polarization characteristic specifying means for specifying a polarization characteristic of the polarized light transmitted through the first polarizer based on the change curve; And the change curve calculation means includes one minimum point of the change curve, and the change curve is calculated based on the amount of light at the rotation angle included in the range of the rotation angle at which the light amount becomes equal to or less than a predetermined value. It provides the polarization measuring device characterized by the above-mentioned.

Further, in order to achieve the above object, the present invention has a second polarizer for incident polarized light polarized by the first polarizer, the detection unit for detecting the amount of light transmitted through the second polarizer while rotating the second polarizer And a polarization measuring device for specifying a polarization characteristic of polarized light transmitted through the first polarizer based on a detection result of the detection unit, wherein the detection unit introduces the light including an incidence component to introduce the second polarizer. A first aperture incident to the light source, diffusion means for diffusing light transmitted through the second polarizer, a second aperture for passing a portion of the light diffused through the diffusion means, and light passing through the second aperture. And a light receiving sensor that detects the amount of light, and the polarization measuring device rotates the second polarizer based on the amount of light at each rotation angle of the second polarizer. Change curve calculation means for obtaining a change curve indicating a periodic change in the amount of light at the time; and polarization characteristic specifying means for specifying a polarization characteristic of the polarized light transmitted through the first polarizer based on the change curve; The curve calculation means includes the one minimum point of the change curve, and calculates the change curve based on the amount of light at the rotation angle included in the range of the rotation angle at which the light amount becomes equal to or less than a predetermined value. A polarization measuring system is provided.

Moreover, in order to achieve the said objective, this invention is a light-orientation irradiation apparatus provided with the polarizer unit which irradiates a polarizing light to the orientation film of the workpiece | work surface mounted on the stage, The said polarizer unit has several unit polarizer arrange | positioned by the horizontal arrangement. And a unit, wherein said unit polarizer unit is equipped with a polarizer, respectively, and is provided with the detection means which detects the polarization characteristic of the light in the said stage equivalence position where the polarized light which passed through the said some polarizer overlaps and is irradiated. .

Moreover, this invention WHEREIN: The said optical direction irradiation apparatus WHEREIN: The said detection means is equipped with the detection part provided so that it can move to the arrangement direction of the said unit polarizer unit. Moreover, the detection part may move also in a stage movement direction.

Moreover, in the said optical orientation irradiation apparatus, the said detection means has a measuring polarizer, the detection part which detects the light quantity which permeate | transmits the said measuring polarizer while rotating the said measurement polarizer, and the said detection part detection On the basis of the results, a polarization measuring device for specifying the polarization characteristics of the light at the stage equivalent position is provided, wherein the detection unit is disposed at the stage equivalent position, and introduces the light overlapped with the polarized light passing through the plurality of polarizers The polarization measuring device having an aperture incident on the measuring polarizer, a diffusing means for diffusing the light transmitted through the measuring polarizer, and a light receiving sensor for receiving the light diffused by the diffusing means and detecting the amount of light. Is an image when the measuring polarizer is rotated based on the amount of light at each rotation angle of the measuring polarizer. Periodic variation curve calculation to obtain the variation curve showing the variation of the quantity of light means and, based on the variation curve will be the irradiation light polarization characteristics in the stage corresponding position, it characterized in that it includes a polarization characteristic specifying means for specifying.

According to the present invention, the period of light amount when the second polarizer is rotated based on the amount of light at each rotation angle obtained by detecting the light transmitted through the first polarizer and the second polarizer in order while the second polarizer is rotated. In obtaining a change curve representing a change in general, the change curve is calculated based on the amount of light at the rotation angle that includes one minimum point of the change curve and is included in the range of the rotation angle at which the light amount becomes equal to or less than a predetermined value. It was.

Thereby, since the change curve is calculated | required based on the detection value whose noise component contained in a detection value is small compared with the detection value of the light quantity of the maximum point vicinity, the accuracy of a change curve becomes high. And a polarization characteristic is calculated | required with high precision by obtaining a polarization characteristic from this change curve.

Since only the quantity of light in the vicinity of the minimum point needs to be measured, high precision measurement can be performed with a small number of measurements.

Moreover, according to this invention, it was set as the structure which detects the polarization characteristic of the light in the said position correspondence position to which the polarized light which passed the some polarizer was irradiated overlapping.

Thereby, since the polarization characteristic of the polarized light actually irradiated to the alignment film of the workpiece | work surface arrange | positioned at the stage can be detected, the polarization characteristic in actual irradiation light can be measured with high precision and without lack.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the structure of the polarization measurement system which concerns on 1st Embodiment of this invention with an optical alignment apparatus.
FIG. 2 is a view showing a configuration of a polarization measuring system together with a plan view of a light alignment device. FIG.
3 is a schematic diagram illustrating a configuration of a detection unit.
4 is a schematic diagram of a change curve of detection light.
5 is an explanatory diagram of a range of rotation angles for detecting a light amount of detection light.
6 is an explanatory diagram of a specific example of detection of the amount of light of detection light.
7 is a flowchart illustrating a measurement operation of a polarization measurement system.
8 is an external perspective view illustrating a configuration of a detection unit.
9 is a sectional view of a detection unit.
10 is a diagram illustrating a configuration of a photoalignment device according to a second embodiment of the present invention.
11 is a graph showing the relationship between the irradiation position and the relative irradiation light amount.
12 is an explanatory diagram showing a relationship between a polarizer unit and a detection unit from a short axis side;
It is a figure which shows the structure of a polarizer unit, (A) is a top view, (B) is the figure seen from the side cross section.
14 is a schematic diagram illustrating a polarization axis adjusting device.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention is described with reference to drawings.

<1st embodiment>

FIG. 1: is a schematic diagram which shows the structure of the polarization measurement system 1 which concerns on this embodiment with the optical alignment apparatus 2. FIG.

In FIG. 1, the photo-alignment apparatus (photo-alignment irradiation apparatus) 2 is an irradiation apparatus which irradiates and polarizes polarized light to the photo-alignment film of a plate-shaped or strip | belt-shaped photo-alignment object (work), and polarizes a polarization measurement system. (Detection means) 1 measures the polarization characteristic of the irradiation light of the photo-alignment apparatus 2. As shown in FIG. As a polarization characteristic, the polarization axis and extinction ratio of polarized light are measured.

The photo-alignment apparatus 2 is equipped with the stage conveyance mount 3, the irradiator mounting mount 4, and the work stage (stage) 5 on which the optical orientation object is mounted.

The irradiator mounting mount 4 is styled to extend across the width direction (direction perpendicular to the linear direction X of the linear motion mechanism to be described later) of the stage conveyance stand 3 at an upper position spaced apart from the stage conveyance stand 3 by a predetermined distance. The pillars are fixed to the stage transport stand 3. The irradiator mounting mount 4 incorporates the irradiator 6, and the irradiator 6 irradiates the polarized light directly below. In addition, in order to isolate | separate the vibration accompanying the movement of the work stage 5, and the vibration resulting from cooling of the irradiator 6, the stage conveyance mount 4 is not fixed to the stage conveyance mount 3, but the said stage conveyance is carried out. The structure may be provided separately from the mount 3. The stage conveyance mount 3 and the irradiator mounting mount 4 may have a dustproof structure.

The stage conveying mount 3 has a built-in linear motion mechanism (not shown) for conveying the work stage 5 so that the surface of the stage conveying mount 3 passes directly under the irradiator 6 along the linear direction X. have. In the optical orientation of the photo-alignment object, the photo-alignment object loaded on the work stage 5 is transferred together with the work stage 5 by the linear motion mechanism to pass directly under the irradiator 6, and at the time of the passage. It exposes to polarized light and orients a photo-alignment film.

The irradiator 6 is provided with the lamp 7 which is a light source, the reflector 8, and the polarizer unit 10, and irradiates the polarized light which condenses directly underneath.

The lamp 7 is a discharge lamp, and an ultraviolet lamp of a straight tube (bar shape) extending at least equal to or more than the width of the light alignment object is used. The reflector 8 is a cross-sectional oval and a cylindrical concave reflector extending along the longitudinal direction of the lamp 7, and collects light from the lamp 7 and irradiates it toward the polarizer unit 10.

The polarizer unit 10 is arrange | positioned between the reflecting mirror 8 and a photo-alignment object, and polarizes the light irradiated to a photo-alignment object. By irradiating this polarization light on the photo-alignment film of a photo-alignment object, the said photo-alignment film is orientated.

FIG. 2 is a view showing the polarization measurement system 1 together with the plan view of the optical alignment device 2. In addition, in FIG. 2, only the polarizer unit 10 is shown in the irradiator mounting mount 4 in order to understand the structure of the polarizer unit 10 easily.

As shown in FIG. 2, the polarizer unit 10 includes a plurality of unit polarizer units (first polarizers) 12 and a frame 14 for aligning the unit polarizer units 12 in a horizontal array. Doing. The frame 14 is a plate-shaped frame in which each unit polarizer unit 12 is arranged in a row. The unit polarizer unit 12 is provided with the wire grid polarizer (polarizer) 16 formed in substantially rectangular plate shape.

In this embodiment, each unit polarizer unit 12 supports the wire grid polarizer 16 so that a wire direction may become parallel to the linear direction X of the said work stage 5, and the direction orthogonal to this wire direction A, The arrangement direction B of the wire grid polarizer 16 is made to correspond.

The wire grid polarizer 16 is a kind of linear polarizer. As described above, since the lamp 7 has a rod shape, light of various angles is incident on the wire grid polarizer 16, but the wire grid polarizer 16 is linearly polarized and transmitted even if the light is obliquely incident.

The wire grid polarizer 16 is supported by the unit polarizer unit 12 so as to rotate in-plane with its normal direction as the rotation axis and to fine-tune the direction of the polarization axis C1. With respect to all the unit polarizer units 12, the polarization axis C1 of the wire grid polarizer 16 is finely adjusted so as to be aligned in a predetermined irradiation reference direction, so that the polarization axis C1 is highly precisely over the entire length of the long axis direction of the polarizer unit 10. Aligned polarized light is obtained, and high quality light orientation is attained.

The polarization measurement system 1 is equipped with the polarization measurement apparatus 20 and the measurement unit 30, as shown in FIG. The measurement unit 30 is provided with the detection part 31 which detects polarized light, and the polarization measurement apparatus 20 measures the polarization axis and extinction ratio of the said polarized light based on the detection result of the polarized light by the detection part 31.

The measuring unit 30 is provided with the linear guide 32 which guides the detection part 31 along a straight line as shown in FIG. When measuring the polarized light, the linear guide 32 is connected to the side surface 5A of the traveling direction side of the work stage 5 to be transferred directly below the polarizer unit 10, or the linear guide 32 is a polarizer unit. It is provided on the stage conveyance stand 3 so that it may be located just below (10). Then, the detector 31 is moved along the linear guide 32 or is frequently moved so as to be located directly below the wire grid polarizer 16 to be fine-tuned, and transmitted through the wire grid polarizer 16 at the position. The polarizing light is detected by the detection part 31, and the polarization characteristic of irradiation light is measured.

3 is a schematic diagram showing the configuration of the detector 31.

The detection part 31 is equipped with the detection side polarizer (2nd polarizer, measurement polarizer) 33, and the light receiving sensor 34. As shown in FIG.

The detection side polarizer 33 is a plate-shaped linear polarizer for light detection having a polarization axis C2 (a disk shape in the illustrated example) and is also called an analyzer. The polarizing light F which penetrates the wire grid polarizer 16 and linearly polarizes into this detection side polarizer 33, and makes this polarizing light F linearly polarize. Arbitrary polarizer can be used for the detection polarizer 33 as long as it is a linear polarizer, for example, you may use a wire grid polarizer.

The light receiving sensor 34 receives the detection light G linearly polarized on the polarization axis C2 of the detection side polarizer 33, and outputs a detection signal 35 indicating the light amount I to the polarization measurement apparatus 20.

In the detection part 31, the detection side polarizer 33 is provided so that rotation is possible over at least 1 rotation using the normal line direction S as a rotation axis. The rotation of the detection side polarizer 33 is defined by the rotation angle θ from the reference position P0. In the present embodiment, the reference position P0 is set to a position where the direction of the polarization axis C2 coincides with the irradiation reference direction of the wire grid polarizer 16. That is, when the detection part 31 was set to the linear guide 32 and the detection side polarizer 33 was matched with the reference position P0, the polarization axis C2 of the detection side polarizer 33 was directed toward the irradiation reference direction. do.

The polarization measurement apparatus 20 measures the polarization axis and the extinction ratio of the polarized light F based on the periodic change in the amount of light of the detection light G when the detection side polarizer 33 rotates once. Specifically, as shown in FIG. 2, the polarization measuring device 20 includes a rotation drive control unit 21, an input unit 22, a change curve calculation unit 23, a polarization characteristic specifying unit 24, And a polarization characteristic output section 25. In addition, the polarization measurement apparatus 20 can also be implemented by executing a computer-readable program which implements each part shown in FIG. 2, for example in a personal computer.

The rotation drive control unit 21 controls the rotation of the detection side polarizer 33 of the detection unit 31. Specifically, the detection part 31 is equipped with the rotary actuator which rotates the detection side polarizer 33, and the rotation drive control part 21 controls the rotary actuator and rotates the detection side polarizer 33, and the polarization axis C2 is changed. It adjusts to the direction of predetermined rotation angle (theta). The rotation angle θ at this time is output to the change curve calculation unit 23.

The input part 22 is a means which receives the input of the detection value of the light quantity I of the detection light G, and the detection signal 35 of the detection part 31 is input to this input part 22. As shown in FIG. The input part 22 acquires the detection value of the light quantity I of the detection light G from the said detection signal 35, and outputs it to the change curve calculation part 23. FIG.

The change curve calculation unit 23 is a change indicating a periodic change in the light amount I of the detection light G when the detection side polarizer 33 is rotated one based on the detection value of the light amount I of the detection light G. The curve Q is calculated. In detail, the detection light G, as shown in FIG. 3 mentioned above, sequentially orders the wire grid polarizer 16 and the detection side polarizer 33 in which the emitted light E of the lamp 7 is a linear polarizer. It is light obtained by passing through.

Therefore, the change curve Q of the light quantity I of the detection light G accompanying the rotation of the detection side polarizer 33 is ideally, as shown in FIG. 4, the polarization axis C2 of the detection side polarizer 33 is When parallel to the polarization axis C1 of the wire grid polarizer 16 (in this embodiment, the rotation angle θ = 0 °, 180 ° (maximum point)) becomes the maximum light amount Imax (maximum value), and the polarization axis C2 is orthogonal to the polarization axis C1 In the present embodiment, the cosine waveform shown in the following equation (1) in which the rotational angle θ = 90 ° and 270 ° (minimum point) is a period [pi] (rad) (= 180 °) in which one period of the minimum light amount Imin (minimum value) [So-called Low of Malus].

Is the amplitude, β is the period, and γ is the phase shift (the phase difference of the polarization axis C1 of the wire grid polarizer 16 with respect to the reference position P0), and? Is a bias component.

However, through earnest experiments, the inventors obtained the following knowledge about the change curve Q.

That is, since the photoalignment apparatus 2 uses the lamp 7 which is a discharge lamp as a light source, by the various factors, such as the fluctuation | variation of the lighting power of the power supply device which turns on the lamp 7, and the cooling state of the lamp 7, The light source brightness fluctuates in a very short time period, causing fluctuations or instabilities, which become noise components of the light source brightness.

In addition, since the photo-alignment device 2 irradiates the polarized light F in a wide range from the lamp 7 through the polarizer unit 10, the light-receiving sensor 34 of the detector 31 has polarized light of various incidence angles. (F) enters and the polarized light F which has passed through the other wire grid polarizer 16 adjacent to the wire grid polarizer 16 to be adjusted also enters and is detected.

Due to the noise component of the light source luminance, the incidence of polarized light F, and the like, the change curve Q obtained from the detection result of the detection unit 31 is deformed from the ideal cosine function (Equation 1). The approximation is sufficiently approximated by an n-square cosine waveform (n≥2) shown in the following expression (2).

According to the above knowledge, as the change curve Q, it is best to obtain an n-square cosine waveform based on the detection value of the amount of light of the detection light G, but in doing so, the measurement and calculation of many detection light G There is a problem that it is necessary.

In addition, since the extinction ratio is divided by the minimum amount of light Imin and dividing the maximum amount of light Imax, as the minimum amount of light Imin decreases, the noise component occupying the minimum amount of light Imin greatly affects the value of the extinction ratio. When Q) is obtained, the repetition accuracy of the minimum light amount Imin is bad, and therefore the extinction ratio is not obtained accurately.

Therefore, the number of measurement points for obtaining one change curve Q, the plurality of measurements may be repeated, and the change curve Q may be obtained and averaged a plurality of times so that a desired precision is obtained. There is a problem that the measurement takes time because it is very large.

As a method of solving this problem, a light receiving sensor provided separately from the detection unit 31 is prepared so that the noise component of the light source luminance can be removed from the detection signal 35 of the detection unit 31, and a light receiving sensor installed separately. It is conceivable to detect the light amount I of the detection light G for reference and to perform a process of removing a noise component from the detection signal 35 of the detection unit 31 based on the reference detection result.

However, in the polarization measurement, the polarization state is also changed in general even when light passes through an optical element such as a mirror or prism, so that the detection light G incident on the detection unit 31 is branched to the separately installed light receiving sensor. Can not. For this reason, the detection light G received by the detection part 31 and the light reception sensor of a separate installation will differ, and a noise component is not removed correctly.

In addition, the light amount I of the detection light G detected by the light receiving sensor 34 of the detection unit 31 changes with the rotation of the detection side polarizer 33, and the amount of noise component of the light source luminance also changes with it. Therefore, the process which reflects the rotation angle (theta) of the detection side polarizer 33 is needed with respect to the detection value of the light reception sensor of a separate installation. In addition, when comparing the light reception sensor 34 with the detection part 31 and the light reception sensor of a separate installation, it is also necessary to correct | amend the difference of both light reception characteristics resulting from the aging change of sensor sensitivity, the noise resulting from a temperature characteristic, etc. .

As described above, the measuring method using the separately installed light receiving sensor includes many problems that must be solved in order to realize high-precision measurement.

Therefore, in this embodiment, the detection value of the light quantity I used for the curve fitting of the change curve Q is shown in FIG. 5 near the minimum point where the light quantity I of the detection light G becomes the minimum ( By limiting to the one detected at W), it is possible to calculate the change curve Q having high repeat accuracy at a few measurement points while being measured by one light receiving sensor 34.

In detail, if the ratio of the noise component of the light source luminance to the light amount I of the detection light G is substantially constant, the magnitude of the noise component is increased in proportion to the light amount I of the detection light G, and thus, the above-mentioned FIG. As shown in Fig. 4, the magnitude of the noise component is smaller in the vicinity of the minimum light amount Imin (minimum point) than in the vicinity of the maximum light amount Imax (maximum point). In other words, in the vicinity of the minimum light amount Imin, the fluctuation range of the light amount I due to the influence of the noise component of the light source brightness is smaller than the vicinity of the maximum light amount Imax.

Therefore, the change curve Q is obtained by curve fitting using the detected value of the light quantity I near the minimum light quantity Imin with less influence of the noise component, thereby suppressing the noise component caused by the influence of fluctuations in the light source brightness or the like. The curve Q is obtained. Since the influence of the noise component of the light source brightness is suppressed, the repeating accuracy is increased, and the change curve Q with high reliability is obtained even in one measurement.

The inventors earnestly experiment, and the range (W) is a range in the vicinity of the minimum light amount Imin, if the light amount I of the detection light G is a range W of the rotation angle θ that is 20% or less of the maximum light amount Imax. Based on the light amount I of the detection light G measured at the rotation angle θ in the circuit, knowledge of suppressing the influence of the noise component of the light source brightness and obtaining a change curve Q with high repeating accuracy was obtained. . Further, the inventors have obtained the knowledge that the minimum light amount Imin is included in the above range W if the range is ± 20 ° with respect to the rotation angle θa obtained.

Based on these knowledge, in this embodiment, as shown in FIG. 5, it detects by four rotation angles (theta) ((theta) = (theta) a +/- 10 degree, (theta) a +/- 20 degree) contained in this range (W). The light quantity I of the light G is detected, and the said change curve Q is calculated | required by curve fitting based on the light quantity I in each rotation angle (theta).

Since the rotation angle θ for detecting the light amount I of the detection light G is separated by about 10 °, a significant difference can be generated between the detected values of the light amount I of the detection light G, so that the difference in the detected value The change curve Q can be reliably obtained without being buried in the noise component of the light source luminance.

In addition, the rotation angle (theta) which measures the light quantity I of the detection light G is not limited to 4 points | pieces, It should just be at least 3 points or more as it exists in the range of the said range W.

The change curve calculation unit 23 curve-fits the cosine waveform shown in Equation 1 based on the detection value of the light amount I of the detection light G at the rotation angle θ included in the range W. It also calculate | requires by the method of regression), and outputs it to the polarization characteristic specifying part 24. FIG.

When the polarization direction of the polarized light F is shifted from the direction of the reference position P0, that is, when the direction of the polarization axis C1 of the wire grid polarizer 16 is shifted from the array direction B which is the direction of the reference position P0 As shown by an imaginary line in FIG. 4, the deviation is represented by the phase shift γ (> 0) on the change curve Q. FIG.

The polarization characteristic specifying unit 24 is based on the change curve Q obtained by the change curve calculating unit 23, and the polarization direction of the polarized light F (that is, the direction of the polarization axis C1 of the wire grid polarizer 16). And the extinction ratio is specified and output to the polarization characteristic output unit 25.

Specifically, as shown in FIG. 4, the polarization characteristic specifying unit 24 is the γ which is the rotation angle θ (maximum point) at which the maximum light amount Imax of the detection light G is obtained in the change curve Q. As shown in FIG. By specifying the direction of the polarization axis C1, the extinction ratio is specified based on the ratio (= maximum light amount Imax / minimum light amount Imin) of the maximum light amount Imax and the minimum light amount Imin of the change curve Q. The maximum light amount Imax in the change curve Q is obtained by substituting the rotation angle θ = γ (maximum point) in the change curve Q, and the minimum light amount Imin is the rotation angle θ = 90 ° + γ (minimum point). It is saved by substitution.

The polarization characteristic output unit 25 outputs the polarization characteristics (polarization axis and extinction ratio) specified by the polarization characteristic specifying unit 24. The form of this output is arbitrary as long as a user can use a polarization characteristic, For example, display, the output to another electronic device, the recording to a recording medium, etc. are mentioned.

Here, the rotation angle θa (minimum point) at which the minimum light amount Imin is obtained is 180 in phase while the detection side polarizer 33 is rotated one time (θ = 0 to 360 °) as shown in FIG. 4 described above. Since it exists in two places separated by ((pi)), in this embodiment, the change curve calculation part 23 rotates four points in the range W with respect to each of two rotation angles (theta) = (theta) a and (theta) a + 180 degrees. The light amount I of the detection light G is measured at an angle θ to obtain two change curves Q, and the polarization characteristic specifying unit 24 obtains the polarization axis and extinction ratio for each of the two change curves Q. By measuring these average values, the measurement accuracy of the polarization axis and the extinction ratio is increased.

In addition, in this embodiment, the light quantity I of the detection light G in four rotation angles (theta) in each of the said ranges W for every two rotation angles (theta) = (theta) a and (theta) a + 180 degrees. In order to increase the detection accuracy, the measurement of the amount of light I is repeated a plurality of times (for example, ten times) at the same rotation angle θ.

As a result, as shown in FIG. 6, M detected values of the light quantity I (M≥2) are obtained for every same rotation angle (theta). When the change curve calculation unit 23 obtains the change curve Q from these detection values, N detection values (M≥N≥1) are selected at each rotation angle θ, and these N pieces are selected. The average value of the detected values is obtained, and a change curve Q is obtained based on these average values. Since the number of combinations when selecting N from the M detection values is MCn, the change curve calculation unit 23 obtains the change curve Q for each of these MCn combinations. And the polarization characteristic specifying part 24 calculates | requires a polarization axis and extinction ratio with respect to each of MCn change curves Q, and calculates the average value of each polarization axis and each extinction ratio. Thereby, a polarization axis and extinction ratio are calculated | required further with high precision.

7 is a flowchart showing the measurement operation of the polarization measurement system 1.

As shown in FIG. 7, the polarization measuring apparatus 20 controls the rotation of the detection side polarizer 33 of the detection unit 31 to adjust the rotation angle θ to the measurement point (step S1). In this embodiment, the measuring point of rotation angle (theta) is eight points of (theta) = (theta) a +/- 20 degree, (theta) a +/- 10 degree, (theta) + +180 degree +/- 20 degree, and (theta) + + 180 degree +/- 10 degree as shown in FIG. The rotation angle θa is an angle (minimum point) at which the minimum light amount Imin is obtained, and is defined by θa = 90 ° + γ as shown in FIG. 4 described above. In this embodiment, gamma = 0 in an ideal state without deviation of the polarization axis C1. Therefore, in the said step S1, the polarization measuring device 20 determines the measuring point of rotation angle (theta) as (theta) a = 90 degrees.

Subsequently, the polarization measuring device 20 intermittently introduces the detection signal 35 of the light amount I of the detection light G over M times, and acquires the detection values of the M light amounts I (step S2).

The polarization measurement apparatus 20 repeatedly executes the above steps S1 and S2 until all detection points of the rotation angle θ are acquired (step S3: YES) of the detection values of the M light quantities I.

Since the polarization measuring apparatus 20 obtains the change curve Q using the detected value of the light quantity I near the minimum light quantity Imin (near the micropoint), four points of rotation angle θ = θa ± 20 ° and θa ± 10 ° Based on the detected value of the light quantity I in, the change curve Q according to the above expression (1) is obtained by curve fitting (step S4). In detail, the polarization measurement apparatus 20 selects N detection values (M≥N≥1) for each rotation angle θ, obtains an average value of these N detection values, and calculates the rotation angle ( The change curve Q is obtained by curve fitting as the detection value of?. As described above, MCn change curves Q are obtained. Subsequently, the polarization measuring apparatus 20 obtains a polarization axis and extinction ratio for each of the MCn change curves Q, and obtains an average value of each polarization axis and extinction ratio (step S5).

The polarization measurement apparatus 20 is changed by curve fitting in the same manner as in steps S4 and S5 based on the detected values of the light amount I at four points of rotation angles θ = θa + 180 ° ± 20 ° and θa + 180 ° ± 10 °. The curve Q is obtained (step S6), and the polarization axis and extinction ratio are specified based on this change curve Q (step S7).

And the polarization measuring apparatus 20 determines the average value of the polarization axis and extinction ratio calculated | required in step S5 and step S7, and specifies the polarization axis and extinction ratio of polarized light (step S8).

Thereby, the polarization axis and extinction ratio of polarized light are calculated | required with high precision.

In addition, in this measurement, the polarization measuring apparatus 20 specifies the rotation angle θ = θa from which the minimum light amount Imin is obtained and the rotation angle θ = γ from which the maximum light amount Imax is determined based on the change curve Q, thereby detecting the detection unit ( The detection side polarizer 33 of 31 may be rotated to actually detect the light amount I of the detection light G at each rotation angle θ, and an extinction ratio may be obtained based on this detection value.

In addition, in the said polarization measurement, even if it does not process step S6-step S8, when the desired precision is obtained, the polarization axis and extinction ratio specified in step S5 are measured, without performing the process of these step S6-step S8. It may be a result. In addition, a user such as an operator may select whether or not the processing of these steps S6 to S8 is performed.

Next, the measurement of the polarized light of the photo-alignment apparatus 2 using the polarization measuring system 1 is demonstrated.

The operator first installs the measuring unit 30 in the optical alignment device 2. In this installation, the operator moves the linear guide 32 such that the guide direction of the linear guide 32 is parallel to the arrangement direction B of the wire grid polarizer 16 and is located directly below the polarizer unit 10. Install. Subsequently, the operator guides the detection part 31 by the linear guide 32, arrange | positions it directly under the wire grid polarizer 16 of a measurement object, and uses this polarization measurement system 1, and this wire grid polarizer ( The polarized light F emitted from 16 is detected, and the polarization axis C1 and extinction ratio of the wire grid polarizer 16 are measured. The operator finely adjusts the rotation of the wire grid polarizer 16 as necessary based on the measurement result of the polarization axis C1 to adjust the direction of the polarization axis C1 to a predetermined direction (array direction B in the present embodiment).

The worker performs the operation of aligning the direction of the polarization axis C1 to the array direction B based on the measurement of the polarized light F and the measurement result of the wire grid polarizer 16 included in the polarizer unit 10 in the same manner. The directions of the polarization axis C1 of all the wire grid polarizers 16 are aligned in the array direction B. FIG.

As described above, according to this polarization measurement system 1, even if the same measurement is not performed a plurality of times, a change curve Q having high repeatability and high reliability is obtained, and from this change curve Q, the direction of the polarization axis C1 is obtained. This high precision is specified. Therefore, when fine-tuning the individual wire grid polarizer 16, the number of measurements of the polarized light F can be reduced, and the direction of the polarization axis C1 can be adjusted with high precision, while terminating fine adjustment work in a short time.

By the way, in the photo-alignment apparatus 2, the radiation light E of various angles radiate | emitted from the rod-shaped lamp 7 enters into the wire grid polarizer 16, and is linearly polarized by the wire grid polarizer 16, It is emitted.

On the other hand, the detection part which used the Glen Thompson polarization prism for the detection side polarizer 33 is known conventionally. However, since the extinction ratio of the Glan Thompson polarization prism largely changes with the incidence angle, it is necessary to make the incidence angle incident on the detection unit as small as possible.

Therefore, the conventional detection unit can detect only a very limited range of angular components among polarized light F including various angular components output from the wire grid polarizer 16, so that the polarized light F can be accurately measured. none.

Therefore, in this embodiment, by using the detection part 31 of the structure demonstrated below, even the polarized light F containing various angle components, it is possible to detect the range of a wide angle component, and to measure a polarization characteristic.

8 is an external perspective view showing the configuration of the detector 31, and FIG. 9 is a cross-sectional view of the detector 31. As shown in FIG.

As shown in these figures, the detection unit 31 includes a base plate 70 having a rectangular plate shape, on which a light receiving sensor unit 71, a detection side polarizer 33, a rotation stage 72, And a detection light adjusting unit 73 (FIG. 9).

The light receiving sensor unit 71 cools the photomultiplier tube 74, which is an example of the light receiving sensor 34, and the photomultiplier tube 74 to maintain a constant temperature, thereby maintaining the temperature of the photomultiplier tube 74. The liquid cooling base 75 which reduces noise is provided, and the detection signal 35 (FIG. 3) of the photomultiplier tube 74 is introduce | transduced into the polarization measuring apparatus 20. As shown in FIG.

The base mount 70 is coupled to the linear guide 32 and guided linearly by the linear guide 32. By setting one predetermined side of the base mount 70 in accordance with the long axis direction of the linear guide 32, the polarization axis C2 of the reference position P0 and the detection-side polarizer 33 is configured to face the irradiation reference direction. In addition, if the predetermined | prescribed 1 side of the base mount 70 can be installed in the irradiation reference direction, it is not necessary to necessarily use the linear guide 32. As shown in FIG.

The detection side polarizer 33 is disposed directly above the detection surface 74A of the photomultiplier tube 74, and the incident side of the detection light G is covered with an aperture 76 having an opening 76A of a predetermined diameter. have. The aperture 76 restricts incident light to the detection-side polarizer 33, but in this detection unit 31, the wire grid polarizer 16 also transmits the light of the incidence to produce polarized light F. In order to introduce the polarized light F by the components of the incidence yarns, the opening 76A is formed such that the incident angle Y passes through the polarized light F in the range of 0 ° to 70 °.

In addition, the range of the incident angle Y is polarized light emitted obliquely from the wire grid polarizer 16 on the basis of the shape and arrangement of the detector 31, the wire grid polarizer 16, and the lamp 7. It is determined by the angle at which the component of (F) is introduced.

The detection light adjusting unit 73 is a cylindrical member disposed between the detection side polarizer 33 and the detection surface 74A of the photomultiplier tube 74, and includes a cylinder 77 and an aperture 76. The detection light G, which is introduced through the light and passes through the detection-side polarizer 33, is introduced from the upper surface of the cylinder 77, mixed inside, and guided from the lower surface to the photomultiplier tube 74.

Specifically, on the upper surface of the cylindrical body 77 of the detection light adjusting unit 73, an opening 78A for passing the detection light G in the range up to the incident angle Y into which the aperture 76 is introduced is opened. The formed aperture 78 is provided.

In the cylindrical body 77, a diffusion unit 79 for diffusing the transmitted light is provided under the aperture 78 in order to secure a wide light incident angle and to cancel and polarize the polarization state of the light to be introduced. It is installed without putting. The diffusion unit 79 includes two diffusion plates 79A and 79B disposed to face each other at predetermined intervals, and mixes and outputs detection light G having various incident angles Y. As the diffusion plates 79A and 79B, for example, a frosted synthetic quartz plate is used.

The lower surface of the cylindrical body 77 is provided with a plate member 80 having a pinhole 80A for limiting the amount of incident light to the photomultiplier tube 74, so that light passing through the pinhole 80A is transferred to the photomultiplier tube ( Incident on the detection surface 74A of 74.

Further, a wavelength limiting filter 81 is provided between the pinhole 80A and the detection surface 74A of the photomultiplier tube 74 to cut light having a wavelength other than the wavelength of the photo-alignment action. The light from which the disturbance light is cut is induced into the photomultiplier tube (74).

Thus, since the detection part 31 introduces polarized light F to the range of the comparatively large incidence angle Y, diffuses it inside, it is set as the structure which detects the light quantity by the photomultiplier tube 74, and is a rod-shaped lamp. Polarized light F including various angle components, such as polarized light F obtained by passing the radiated light E of (7) through the wire grid polarizer 16, detects a range of wide angle components and provides polarization characteristics. It can be measured.

As described above, according to the present embodiment, each rotation angle obtained by detecting the detection light G transmitted through the wire grid polarizer 16 and the detection side polarizer 33 in order while rotating the detection side polarizer 33. One minimum point of the change curve Q when obtaining the change curve Q which shows the periodical change of the light quantity I when the detection side polarizer 33 is rotated one time based on the light quantity I in ((theta)). Each rotation angle which is included in the range W of rotation angle (theta) including the rotation angle (theta) = (theta) a, and the light quantity I becomes below a predetermined value (in this embodiment, about 20% or less of the maximum light quantity Imax). The change curve Q was calculated | required based on the light quantity I in (theta) = (theta) a +/- 20 degree and (theta) a +/- 10 degree.

Thereby, since the change curve is calculated | required based on the detection value with few noise components contained in a detection value compared with the detection value of the light quantity I of the maximum light quantity Imax which is the maximum point, the precision of a change curve becomes high. By obtaining a polarization characteristic from this change curve, a polarization characteristic is calculated | required with high precision.

In addition, since only the light quantity I in the vicinity of the minimum light quantity Imin which is the minimum point needs to be measured, high precision measurement can be performed with a small number of measurements.

Moreover, according to this embodiment, the range (W) of the rotation angle (theta) which contains rotation angle (theta) = (theta) a + 180 degrees which is one minimum point different from said rotation angle (theta) = (theta) a, and the light quantity I becomes below a predetermined value The change curve Q is obtained based on the amount of light I at the rotation angles θ = θa + 180 ° ± 20 ° and θa + 180 ° ± 10 °, and the polarization of the polarized light F is based on this change curve Q. The characteristic is specified and the polarization characteristic of the polarized light F is specified based on the average with the specific polarization characteristic from the change curve Q corresponding to the range W including said rotation angle (theta) = (theta) a. It was set as the structure.

Thereby, when highly accurate measurement is needed, the polarization characteristic of polarized light F is calculated | required more accurately.

Furthermore, in this embodiment, the range W is made into the range which the light quantity I of the detection light G becomes about 20% of light quantity with respect to the maximum light quantity Imax, and the high precision change curve which suppressed the influence of a noise component was carried out. (Q) is obtained.

Moreover, according to this embodiment, the detection part 31 transmits the aperture 76 which injects into the detection side polarizer 33 and introduces the polarization light F containing an incidence component, and the detection side polarizer 33. It was set as the structure which has the diffusing unit 79 which diffuses one light, and the photomultiplier tube 74 as a light receiving sensor which receives the light diffused by this diffusing unit 79, and detects the light quantity I.

Thereby, even if the polarized light F including various angle components like the polarized light F obtained by passing the emission light E of the rod-shaped lamp 7 through the wire grid polarizer 16, The polarization characteristic can be measured by detecting the range.

<2nd embodiment>

Next, with reference to FIGS. 10-14, the 2nd Embodiment of this invention is described.

In the first embodiment described above, the polarization axis C1 is measured for each wire grid polarizer 16, but in the second embodiment, the polarization direction of the polarized light is measured for each place (measurement point) of the optical alignment object. In addition, in 2nd Embodiment, the same code | symbol is attached | subjected to the same part as 1st Embodiment, and description is abbreviate | omitted.

FIG. 10: is a figure which shows the structure of the photoalignment apparatus 100 which concerns on 2nd Embodiment.

The optical alignment device 100 includes a polarization measuring system 1, which is generated from the alignment film for the purpose of increasing the uniformity of the irradiated light and also during the processing of the optical alignment object (during irradiation). For the purpose of preventing the out gas from adhering, the wire grid polarizer 16 is arranged at a predetermined distance away from the alignment film on the surface of the light alignment object as shown in FIG. 10. The optical alignment apparatus 100 is formed similarly to the optical alignment apparatus 1 of 1st Embodiment except the structure provided with the polarization measurement system 1, and the wire grid polarizer 16 and the alignment film distance.

Further, as described above, the radiation light E of various angles emitted from the rod-shaped lamp 7 is incident on the wire grid polarizer 16, and is linearly polarized by the wire grid polarizer 16 to be polarized light ( F) is emitted. Such polarized light F contains various angular components.

As described above, the wire grid polarizer 16 is disposed at a predetermined distance from the alignment film on the surface of the light alignment object, and the polarized light F includes various angular components. Polarized light F passing through 16 is irradiated superimposed. The polarization characteristic of polarized light F is not uniform by the influence of the characteristic deviation by the place of the polarizer which passes, or the influence of an incident angle, but it is irradiated to the polarization light F which has various polarization characteristics to a photo-alignment object. do.

For example, in this embodiment, when the irradiation distribution of the lamp 7 longitudinal direction just under the irradiation machine 6 is isolate | separated for every wire grid polarizer 16 (n-3-n + 1), the graph shown in FIG. In this way, the amount of irradiation light at a certain irradiation position (0 mm) is affected by the three sides. As shown in FIG. 11, even as just below the center of the wire grid polarizer 16, as the irradiation light, the amount of light passing through the wire grid polarizer 16 directly above passes through the surrounding wire grid polarizer 16. It is about half of the amount of irradiation light that adds up to one light amount.

In addition, the structural members, such as the polarizer unit fixing stand 9 which fixes the frame 14 and the frame 14, are formed as a light shielding member, they are comprised by the light shielding member, etc., and are comprised as a light shielding member. . However, the reflection in the structural members such as the frame 14 and the polarizer unit holder 9 cannot be completely prevented. As shown in FIG. 12, the reflected light H reflected from the structural members also becomes scattered light and becomes a work stage ( 5) It is irradiated to the optical alignment object T of phase. The polarization characteristic of the polarized light F is also changed by reflection. The reflected light H also includes light reflected by the alignment film on the surface of the light alignment target T and then reflected by the wire grid polarizer 16.

For this reason, when measuring the polarization axis C1 for every wire grid polarizer 16 by narrowing the introduction angle range of the detection light of the detection part 31, the polarized light F of the wire grid polarizer 16 other than a measurement object, for example. Or the reflected light H cannot be measured. As a result, it cannot be said that the polarization characteristic of the irradiation light actually irradiated to a photo-alignment object was measured correctly.

Therefore, in this embodiment, a wide angle component is obtained by using the detection part 31 which introduces polarized light F to the range of the comparatively large incident angle Y, diffuses it inside, and detects the light quantity in the photomultiplier tube 74. FIG. The range of is detected and the polarization characteristic (polarization direction, extinction ratio) of the polarized light F (irradiation light) actually irradiated to a photo-alignment object can be measured.

The detection light G received by the detection unit 31 is light obtained by sequentially passing the wire grid polarizer 16 and the detection side polarizer 33 in which the emission light E of the lamp 7 is a linear polarizer, The polarized light of the plurality of wire grid polarizers 16 is superimposed light. In other words, the phase shift γ is obtained as the phase difference in the polarization direction of the polarized light F with respect to the reference position P0. Since the detection light G includes polarized light and reflected light of the plurality of wire grid polarizers 16, the polarization direction and extinction ratio of the polarized light are distributed, but the polarization direction and extinction ratio of the polarized light are determined based on the peak value of the distribution. You lose.

By the way, since the wire grid polarizer 16 is formed using materials, such as glass, and is a comparatively fragile optical element, it is hold | maintained in the frame 14 through the buffer material (not shown). More specifically, in the wire grid polarizer 16 in which the polarization axis C1 is adjusted, as shown in FIG. 13, the upper end and the lower end of the unit polarizer unit 12 are framed by screws (fixing means) 19. By being fixed to, it is fixedly arranged on the frame 14. The positional shift of the wire grid polarizer 16 may occur due to aging deterioration of the buffer holding the wire grid polarizer 16 and the vibration of the optical alignment device 100. As a result, the polarization direction of the polarized light is shifted. Throw it away.

In addition, although outgas may generate | occur | produce from an alignment film during the process (irradiation) of a photo-alignment object, when foreign matters, such as this outgas, mix in or adhere to the wire grid polarizer 16, the wire grid polarizer 16 The polarization characteristic of is changed.

In the optical alignment device 100 of the present embodiment, the polarization measurement system 1 does not always measure the polarization characteristic, but, for example, one month after a predetermined period in which the polarization characteristic is changed due to age deterioration, outgas, or the like. The polarization characteristic is measured later.

Subsequently, with reference to FIG. 14, the measurement of the polarized light of the photoalignment device 100 will be described.

14 is a schematic diagram illustrating the polarization axis adjusting device D. FIG.

The polarization axis adjusting device D is a device that includes the polarization measuring system 1A and the spot light source 7A and adjusts the direction of the polarization axis C1 of the wire grid polarizer 16. The polarization measurement system 1A has a polarization measurement system 1 except that the opening (not shown) of the detection unit 31A is narrower than the opening 76A of the detection unit 31 of the polarization measurement system 1. Make the configuration the same as. In addition, in FIG. 14, the same code | symbol is attached | subjected to the part same as the photo-alignment apparatus 100, and description is abbreviate | omitted.

The operator first arranges the polarizer unit 10 in the polarization axis adjusting device D separately installed. Subsequently, the operator arranges the detection part 31A of the polarization axis adjustment device D directly under the wire grid polarizer 16 to be measured, and simultaneously places the spot light source 7A directly on the wire grid polarizer 16 to be measured. To place. Then, the operator detects the polarized light F emitted from the wire grid polarizer 16 using the polarization measuring system 1A, and measures the polarization axis C1 and the extinction ratio of the wire grid polarizer 16. The operator finely adjusts the rotation of the wire grid polarizer 16 as necessary based on the measurement result of the polarization axis C1 to adjust the direction of the polarization axis C1 to a predetermined direction (irradiation reference direction in this embodiment).

The worker performs the operation of aligning the direction of the polarization axis C1 to the irradiation reference direction on the basis of the measurement of the polarized light F and the measurement result similarly for all the wire grid polarizers 16 included in the polarizer unit 10, The directions of the polarization axis C1 of all the wire grid polarizers 16 are aligned in the irradiation reference direction.

Next, the worker installs the adjusted polarizer unit 10 in the optical alignment device 100, and instructs the polarization measurement system 1 to start the measurement of the polarization characteristic (polarization direction, extinction ratio). The polarization characteristic is measured at a plurality of measurement points in the arrangement direction B of the wire grid polarizer 16, but the measurement points are set by the operator and stored in the polarization measurement system 1.

The polarization measurement system 1 guides and arrange | positions the detection part 31 by the linear guide 32 to the predetermined | prescribed predetermined measurement point, detects the polarized light F radiate | emitted from this wire grid polarizer 16, and polarization direction And extinction ratio is measured. When the polarization measurement system 1 measures the polarized light F for all measurement points, the polarization measurement system 1 outputs the result and the pass / fail judgment to the polarization characteristic output section 25. The pass / fail determination value is also set by the operator and stored in the polarization measurement system 1.

As described above, according to the optical alignment device 100, since the polarized light actually irradiated to the optical alignment object is measured, the polarization direction of the polarized light is specified with high accuracy. In the photo-alignment apparatus 100, the polarization characteristic irradiated to the photo-alignment object shows the performance of the photo-alignment apparatus 100, and since it becomes a factor which determines the good or bad of the alignment film oriented by polarized light, the characteristic It is very important to grasp.

The operator terminates the measurement when the polarization characteristic satisfies the criterion at all measurement points, and when the polarization characteristic satisfies the criterion at least, the direction of the polarization axis C1 of the wire grid polarizer 16 is changed in the polarization axis adjusting device D. The polarizer unit 10 is adjusted or maintained. In addition, since the wire grid polarizer 16 is fixed to the frame 14 by the screw 19 after adjustment, in the installation from the polarization axis adjustment device D to the optical alignment device 100, and the like, the polarization axis C1 of the wire grid polarizer 16 is used. The direction of does not change.

As described above, according to this embodiment, the polarization measurement which detects the polarization direction of the light in the position equivalent to the work stage 5 to which the polarized light which passed through the some wire-grid polarizer 16 arrange | positioned in the horizontal arrangement overlaps and is irradiated. It was set as the structure provided with the system 1. By this structure, since the polarization characteristic of the polarized light actually irradiated to the alignment film of the surface of the photo-alignment object arrange | positioned at the work stage 5 can be detected, a polarization direction can be measured with high precision.

Moreover, according to this embodiment, the polarization measurement system 1 was set as the structure provided with the detection part 31 provided so that the movement to the arrangement direction of the unit polarizer unit 12 was possible. By this structure, since the polarization characteristic of each measuring point can be measured in the arrangement direction of the unit polarizer unit 12, the polarization characteristic for every site irradiated to a photo-alignment object can be acquired in detail by making small the space | interval of a measuring point. Can be.

Moreover, according to this embodiment, the detection part 31 transmits the aperture 76 which injects into the detection side polarizer 33 and introduces the polarization light F containing an incidence component, and the detection side polarizer 33. It was set as the structure which has the diffusing unit 79 which diffuses one light, and the photomultiplier tube 74 as a light receiving sensor which receives the light diffused by this diffusing unit 79, and detects the light quantity I.

Thereby, even if the polarized light F including various angle components like the polarized light F obtained by passing the emission light E of the rod-shaped lamp 7 through the wire grid polarizer 16, The polarization characteristic can be measured by detecting the range.

In addition, embodiment mentioned above illustrates one form of this invention to the last, and can be arbitrarily modified and applied in the range which does not deviate from the meaning of this invention.

For example, in embodiment mentioned above, although the lamp 7 which is a discharge lamp was illustrated as a light source of the polarized light measured by the polarization measurement system 1, a light source is not limited to this, It is arbitrary. That is, this invention can be used for the measurement of the linearly polarized polarized light obtained by the light of arbitrary light sources passing through a polarizer. In addition, the light source does not necessarily need to be a linear light source.

For example, although the wire grid polarizer 16 was illustrated as an example of the polarizer which obtains the polarized light of a measurement object in the above-mentioned embodiment, a polarizer is not limited to this. That is, a polarizer is arbitrary as long as it is a polarizer from which linearly polarized polarized light is obtained.

For example, in embodiment mentioned above, although the polarization measurement apparatus 20 illustrated the structure which measures both the polarization axis (or polarization direction) and extinction ratio of polarized light, you may measure only one side. In addition, the polarization measuring device 20 may also measure other characteristics such as light intensity in addition to the polarization axis (or polarization direction) and / or extinction ratio of the polarized light.

For example, in embodiment mentioned above, the polarization measuring device 20 acquires the light quantity of detection light G by inputting the detection signal 35 of the detection part 31 to the polarization measuring device 20. Although it was set as, it is not limited to this. In other words, the recording data in which the correspondence between the rotation angle θ and the amount of light of the detection light G is recorded may be obtained, for example, from another electronic device or a recording medium (for example, a semiconductor memory).

In addition, in the above-mentioned embodiment, although the detection part 31 was provided so that it could move to the arrangement direction B of the unit polarizer unit 12, it is not limited to this, For example, the detection part 31 is a stage moving direction. You may also move.

1, 100, 200: polarization measurement system (detection means)
2: photoalignment apparatus (photoalignment irradiation apparatus)
5: Work stage (stage)
6: irradiator
7: lamp
8: reflector
10: polarizer unit
12: unit polarizer unit
16: wire grid polarizer (first polarizer, polarizer)
20: polarization measuring device
23: change curve calculation unit
24: polarization characteristic specifying unit
30: measuring unit
31: detector
32: linear guide
33: Detection side polarizer (second polarizer, measurement polarizer)
34: light receiving sensor
73: detection light adjusting unit
76: aperture
79 diffusion unit (diffusion means)
A: wire direction
B: array direction
E: radiation
F: polarized light
G: detection light
Q: change curve
T: Light alignment object (workpiece)
W: range
Y: angle of incidence
θ: rotation angle
θa, θa + 180 °: Rotation angle of the minimum point
θa + 90 °, θa + 270 °: Rotation angle of the maximum point
C1: polarization axis
P0: reference position

Claims (3)

In the photo-alignment irradiation apparatus provided with the polarizer unit which irradiates a polarized light to the orientation film of the workpiece | work surface mounted on the stage,
The polarizer unit includes a plurality of unit polarizer units arranged in a horizontal array, wherein the unit polarizer units each include a polarizer, and polarized light at the stage-equivalent position to which the polarized light passing through the plurality of polarizers is irradiated. Detecting means for detecting a characteristic,
And the detection means includes a detection unit provided to be able to move in the arrangement direction of the unit polarizer unit. delete The method of claim 1, wherein the detection means,
A detecting unit having a measuring polarizer and detecting the amount of light passing through the measuring polarizer while rotating the measuring polarizer;
On the basis of the detection result of the said detection part, the polarization measuring apparatus which specifies the polarization characteristic of the light in the said position equivalence position is provided,
The detection unit,
An aperture that is disposed at the stage equivalent position and introduces light in which polarized light passing through the plurality of polarizers overlaps and enters the measurement polarizer;
Diffusion means for diffusing light transmitted through the measuring polarizer;
It has a light receiving sensor which receives the light diffused by the said diffusion means and detects the said light quantity,
The polarization measuring device,
Change curve calculation means for obtaining a change curve indicating a periodic change in the amount of light when the measurement polarizer is rotated based on the amount of light at each rotation angle of the measurement polarizer;
And a polarization characteristic specifying means for specifying a polarization characteristic of the irradiation light at the stage-equivalent position based on the change curve.

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