TW201411114A - Polarization measuring process, polarization measuring apparatus, polarization measuring system and photo-alignment irradiation apparatus - Google Patents

Abstract

To measure a polarization property of polarization light with high accuracy. Based on a light amount I of light at each rotating angle θ obtained by detecting the light transmitted through in order of a wire grid polarizer 16 and a detecting side polarizer 33 with rotating the detecting side polarizer 33, a change curve Q is calculated which shows periodical change of the light amount I when the detecting side polarizer 33 is rotated. In a case where a polarization property of polarization light F transmitted through the wire grid polarizer 16 is specified based on the change curve Q, the change curve Q is calculated based on the light amount I at the rotating angle θ that is included in a range W of the rotating angle θ which has the rotating angle θ = θ that is one minimum point of the change curve Q and in which the light amount I is lower than or equal to a predetermined value.

Description

Polarized light measuring method, polarized light measuring device, polarized light measuring system and optical alignment irradiating device

The present invention relates to a technique for measuring polarized light.

A technique called optical alignment in which an alignment film or an alignment layer (hereinafter referred to as "optical alignment film") is irradiated with polarized light is known, and the optical alignment is widely used. It is applied to the alignment of a liquid crystal alignment film provided in a liquid crystal display element of a liquid crystal display panel.

An illumination device for light alignment generally includes a light source and a polarizer, and the light of the light source passes through the polarizer to obtain polarized light. In recent years, in order to perform light alignment on a long strip-shaped light alignment film, there has been known an irradiation apparatus in which a rod-shaped lamp having a length corresponding to the width of a light alignment film is used as a light source, and a plurality of polarizers are arranged. In the direction of the long axis of the rod lamp, the linear polarized light is irradiated, and a technique is also proposed in which the width direction of the strip-shaped light alignment film and the irradiation region of the polarized light of the irradiation device are extended. By adhering the light alignment film in the longitudinal direction, the band-shaped photoalignment film is uniformly optically aligned (for example, see Patent Document 1).

As a factor of the polarized light that affects the quality of the light alignment, there are known two kinds of the extinction ratio and the uneven distribution of the polarization axis. As an irradiation device used for the optical alignment, it is important that the light is higher. The accuracy is adjusted. As techniques for measuring polarization characteristics such as the extinction ratio or the polarization axis, various techniques have been proposed (for example, refer to Patent Document 2~ Patent Document 4).

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-163881

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2004-226209

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2005-227019

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2007-127567

In order to obtain a high-quality liquid crystal alignment film by using light alignment, it is necessary to irradiate a polarized light whose extinction is relatively high and whose polarization axis is adjusted with an accuracy of 0.1° or less. In order to adjust the polarization axis with an accuracy of less than 0.1°, the error of the measurement accuracy is required to be within 0.01°, but in the irradiation device using the discharge lamp as a light source, the amount of light is generated due to the fluctuation of the lighting power of the discharge lamp or the like. Fluctuation (flickering), therefore, there is no technique for measuring the polarization characteristics of polarized light with the accuracy of such a requirement.

In the conventional method, there is a problem that since the amount of light fluctuates, it is necessary to repeatedly perform the same measurement and obtain an average to improve the repeating accuracy, and the measurement takes time.

As a technique for measuring a polarization axis, a technique for measuring a polarization axis for each polarizer has been proposed. This technology can use the polarization measurement technology that has been used for a long time. However, in the above method, since the angle of the light taken into the polarimeter is shallow, it is impossible to measure the photoalignment film which is actually irradiated onto the mounting table at various positions irradiated by the polarized rays of the plurality of polarizers. The polarization characteristics of light.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a A polarization measuring method, a polarization measuring device, a polarization measuring system, and a light alignment irradiating device capable of accurately measuring the polarization characteristics of polarized light.

In order to achieve the above object, the present invention provides a method of measuring a polarized light, comprising: a first step of rotating the second polarizer while sequentially transmitting light of the first polarizer and the second polarizer; a change curve indicating a periodic change of the amount of light of the second polarizer at the time of rotation while detecting the amount of light of each of the rotation angles obtained by the detection; and a second step based on the first The change curve obtained in the step specifically defines a polarization characteristic of the polarized light transmitted through the first polarizer; and in the first step, the light amount is equal to or less than a predetermined value based on one minimum point including the change curve The above-described variation curve is obtained by the amount of light at the above-described rotation angle in the range of the above-described rotation angle.

Further, the present invention is characterized in that the third method includes a third step of including a minimum point different from the first step and the range of the rotation angle included in the light amount being equal to or less than a predetermined value. The change curve is obtained by the light amount at the rotation angle; and the fourth step is to specify a polarization characteristic of the polarized light transmitted through the first polarizer according to the change curve obtained in the third step; And a fifth step of specifying a polarization characteristic of the polarized light transmitted through the first polarizer based on an average of the polarization characteristics specified in each of the second step and the fourth step.

Further, the present invention is the polarization measuring method described above, characterized in that the predetermined value is a light amount of about 20% of a maximum value of the light amount.

Further, the present invention is characterized in that the polarized light measuring method is characterized in that the specific transmission is performed based on a rotation angle corresponding to a maximum value of the amount of light indicated by the change curve. a polarization axis of the polarized light of the first polarizer, and/or a maximum value and a minimum value indicated by the change curve, or a rotation of the second polarizer to a polarization axis of the polarized light specified by the change curve The amount of light measured in each of the rotation angle and the rotation angle orthogonal to the polarization axis specifies the extinction ratio of the polarized light transmitted through the first polarizer.

In order to achieve the above object, the present invention provides a polarization measuring apparatus comprising: a change curve calculating means for causing the second polarized light to be transmitted through the first polarizer and the second polarizer in sequence The amount of light of each of the rotation angles obtained by detecting the rotation of the sheet is obtained, and a curve indicating a periodic change of the amount of light when the second polarizer is rotated is obtained; and a polarization characteristic specifying means is based on The change curve specifically defines a polarization characteristic of a polarized light transmitted through the first polarizer; and the change curve calculation means is included in a range of the rotation angle including the minimum amount of the light amount and the light amount is equal to or less than a predetermined value. The above-described variation curve is obtained by the above-described amount of light at the above-described rotation angle.

In order to achieve the above object, the present invention provides a polarization measuring system including: a detecting unit that includes a second polarizer on which a polarized light that is polarized by the first polarizer is incident, and that is (2) detecting a light amount of light transmitted through the second polarizer while rotating the polarizer; and a polarization measuring device that specifies a polarization characteristic of a polarized light transmitted through the first polarizer based on a detection result of the detecting unit; and the detecting unit And a first aperture having a light containing an oblique incident component and incident on the second polarizer; and a diffusion means for diffusing light transmitted through the second polarizer; the second aperture And passing a portion of the light diffused by the diffusion means; and receiving a light sensor that receives the light passing through the second aperture and detecting the amount of light; and the polarization measuring device includes: a curve calculation means according to a change curve indicating a periodic change of the amount of light of the second polarizer at the time of rotation of the second polarizer at a rotation angle; and a polarization characteristic specifying means according to the change curve a polarization characteristic of the polarized light that is transmitted through the first polarizer; and the change curve calculation means is included in a range of the rotation angle including the minimum amount of the light amount and the light amount is equal to or less than a predetermined value. The above-described change curve is obtained by the above-described amount of light of the above-described rotation angle.

In order to achieve the above object, the present invention provides a light alignment irradiation device including a polarizer unit that irradiates a polarizing ray to an alignment film placed on a surface of a workpiece on a mounting table, and is characterized in that the polarizer unit has a horizontal a plurality of unit polarizer units arranged in a row, wherein the unit polarizer units are respectively provided with polarizers, and the light alignment irradiating device is provided with the above-mentioned illumination light that is superposed on the polarized light passing through the plurality of polarizers A detection means for detecting the polarization characteristics of light at a position corresponding to the stage.

Further, the present invention is directed to the optical alignment irradiating apparatus, wherein the detecting means includes a detecting portion that is provided to be movable in an array direction of the unit polarizer unit. Further, the detecting unit can also move in the moving direction of the mounting table.

Furthermore, the present invention is characterized in that the detecting means includes a detecting unit that includes a polarizing plate for measurement, and detects the amount of light transmitted through the measuring polarizer while rotating the measuring polarizer. And a polarization measuring apparatus that specifies a polarization characteristic of light at a position corresponding to the mounting table based on a detection result of the detecting unit; and the detecting unit has an aperture that is disposed at a position corresponding to the mounting table, and is taken in the plural The polarized light of the polarizers generates the superposed light and is incident on the polarizer for measurement; the diffusion means diffuses the light transmitted through the polarizer for measurement; and the light receiving sensor receives the light by the above Diffusion means the light that spreads In the above-described polarization measuring device, the polarization measuring device includes a change curve calculation means for determining the amount of light when the measurement polarizer is rotated, based on the amount of light of each of the rotation angles of the measurement polarizer. A variation curve of the periodic variation; and a specific means for the polarization characteristic, which is based on the above-described variation curve, and specifies a polarization characteristic of the illumination light at a position corresponding to the mounting table.

According to the present invention, the amount of light at each rotation angle obtained by detecting the rotation of the second polarizer while sequentially transmitting the light of the first polarizer and the second polarizer is configured. The curve of the periodic change of the amount of light of the second polarizer during the rotation is obtained. In this case, the rotation angle is included in the range of the rotation angle including the minimum amount of the light curve and the amount of rotation below the predetermined value. The amount of light is used to determine the curve.

Thereby, the change curve is obtained based on the detected value of the noise component included in the detected value as compared with the detected value of the amount of light near the maximum point, so that the accuracy of the change curve is improved. Further, by obtaining the polarization characteristics from the variation curve, the polarization characteristics can be accurately obtained.

Further, since only the amount of light in the vicinity of the minimum point can be measured, it is possible to achieve high-accuracy measurement with a small number of measurement times.

Moreover, according to the present invention, it is assumed that the polarization characteristics of the light at the position corresponding to the mounting table that is irradiated by the polarization of the plurality of polarizers are detected.

Thereby, the polarization characteristics of the polarized light that is actually irradiated onto the alignment film disposed on the surface of the workpiece on the mounting table can be detected, so that the polarization characteristics in the actual irradiation light can be appropriately and accurately measured.

1, 1A, 100, 200‧ ‧ polarized light measurement system (detection means)

2‧‧‧Light alignment device (light alignment device)

3‧‧‧Loading table pedestal

4‧‧‧ illuminator setting pedestal

5‧‧‧Working table (mounting table)

5A‧‧‧Side side of the traveling direction side of the workpiece mounting table 5

6‧‧‧ illuminator

7‧‧‧ lights

7A‧‧‧ point light source

8‧‧‧Mirror

9‧‧‧Polarizer unit fixed table

10‧‧‧Polarizer unit

12‧‧‧Unit polarizer unit

14‧‧‧Frame

16‧‧‧Wire grid polarizer (first polarizer, polarizer)

19‧‧‧ screws

20‧‧‧Polarization measuring device

21‧‧‧Rotary Drive Control

22‧‧‧ Input Department

23‧‧‧Change curve calculation section

24‧‧‧Special part of polarization characteristics

25‧‧‧Polarization characteristic output unit

30‧‧‧Measurement unit

31, 31A‧‧‧Detection Department

32‧‧‧Linear guide

33‧‧‧Detecting side polarizer (2nd polarizer, measuring polarizer)

34‧‧‧Photodetector

35‧‧‧Detection signal

70‧‧‧Base

71‧‧‧Photodetector unit

72‧‧‧Rotating table

73‧‧‧Detection light adjustment unit

74‧‧‧Photomultiplier

74A‧‧‧Detection surface of photomultiplier tube 74

75‧‧‧Water-cooled substrate

76‧‧‧Aperture

76A‧‧‧ openings

77‧‧‧Cylinder

78‧‧‧Aperture

78A‧‧‧ Opening

79‧‧‧Diffusion unit (diffusion means)

79A, 79B‧‧‧ diffuser board

80‧‧‧ plates

80A‧‧ pinhole

81‧‧‧Wavelength limiting filter

A‧‧‧ direction

B‧‧‧Orientation

C1, C2‧‧‧ polarizing axis

D‧‧‧ Polarized axis adjustment device

E‧‧‧radiation

F‧‧‧ polarized light

G‧‧‧Detecting light

H‧‧‧ reflected light

I‧‧‧Light quantity

I _max ‧‧‧Maximum amount of light

I _min ‧‧‧Minimum amount of light

P0‧‧‧ reference position

Q‧‧‧change curve

S‧‧‧ normal direction

T‧‧‧Light alignment object (workpiece)

W‧‧‧Scope

X‧‧‧linear motion direction

Y‧‧‧ incident angle

Θ‧‧‧ turning angle

Θa, θa+180°‧‧‧The angle of rotation of the minimum point

Θa+90°, θa+270°‧‧‧maximum angle of rotation

Fig. 1 is a view showing a configuration of a polarization measuring system according to a first embodiment of the present invention together with a light alignment device.

Fig. 2 is a view showing a configuration of a polarization measuring system together with a plan view of the optical alignment device.

Fig. 3 is a schematic view showing the configuration of a detecting unit.

Fig. 4 is a schematic view showing a curve of the detected light.

Fig. 5 is an explanatory diagram of a range of a rotation angle at which the amount of light of the detection light is detected.

Fig. 6 is an explanatory diagram showing a specific example of detecting the amount of light light.

Fig. 7 is a flow chart showing the measurement operation of the polarization measuring system.

Fig. 8 is a perspective view showing the appearance of a detecting unit.

Figure 9 is a cross-sectional view of the detecting portion.

Fig. 10 is a view showing the configuration of an optical alignment device according to a second embodiment of the present invention.

Fig. 11 is a graph showing the relationship between the irradiation position and the amount of relative irradiation light.

Fig. 12 is an explanatory view showing the relationship between the polarizer unit and the detecting unit from the short axis side.

Fig. 13 is a view showing the configuration of a polarizer unit, wherein (A) is a plan view and (B) is a side cross-sectional view.

Fig. 14 is a schematic view showing a polarizing shaft adjusting device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<First embodiment>

Fig. 1 is a schematic view showing the configuration of the polarization measuring system 1 of the present embodiment together with the optical alignment device 2.

In the figure, the light alignment device (light alignment illumination device) 2 is used for plate-like or strip-shaped light distribution. An apparatus for irradiating a light-aligning light to a light-aligning film of an object (workpiece) to perform light-aligning, and a polarization measuring system (detecting means) 1 is a method of measuring a polarizing characteristic of the light of the light-aligning device 2. As the polarization characteristics, the polarization axis of the polarized light and the extinction ratio were measured.

The optical alignment device 2 includes a mounting table transfer pedestal 3, an illuminator mounting pedestal 4, and a workpiece mounting table (mounting table) 5 on which the light aligning object is placed.

The illuminator installation pedestal 4 is a door that is transversely positioned in the width direction of the stage transfer pedestal 3 (perpendicular to the linear motion direction X of the linear motion mechanism described below) from a position above the predetermined distance from the stage transfer pedestal 3 The two columns are fixed to the stage transfer pedestal 3. The illuminator is provided with a pedestal 4 in which the illuminator 6 is built, and the illuminator 6 illuminates the polarized ray directly below. Further, in order to separate the vibration accompanying the movement of the workpiece mounting table 5 from the vibration caused by the cooling by the illuminator 6, the illuminator mounting pedestal 4 may be fixed to the mounting table transfer pedestal 3, and the mounting table transfer pedestal may be omitted. 3 separate configuration. The stage transfer pedestal 3 and the illuminator installation pedestal 4 may have an anti-vibration structure.

A linear motion mechanism (not shown) is disposed in the mounting table pedestal 3, and the linear motion mechanism transfers the workpiece carrier directly below the illuminator 6 on the surface of the stage transfer pedestal 3 in the linear motion direction X. Set up 5. When the light is aligned with the object, the light-aligning object placed on the workpiece mounting table 5 is transferred together with the workpiece mounting table 5 by the linear motion mechanism and passed directly under the illuminator 6, and exposed during the passage. The light alignment film is aligned under polarized light.

The illuminator 6 includes a lamp 7 as a light source, a mirror 8, and a polarizer unit 10, and illuminates the condensed polarized ray directly below.

The lamp 7 is a discharge lamp, and a straight tube type (rod-shaped) ultraviolet lamp that extends at least equal to the width of the light-aligning object is used. The mirror 8 is a columnar concave mirror having an elliptical cross section and extending in the longitudinal direction of the lamp 7, and condenses the light of the lamp 7 and irradiates it toward the polarizer unit 10.

The polarizer unit 10 is disposed between the mirror 8 and the light-aligning object, and polarizes the light that is incident on the light-aligning object. The light alignment film is aligned by irradiating the polarized light to the light alignment film of the light-aligning object.

FIG. 2 is a plan view showing the polarization measuring system 1 and the optical alignment device 2 together. In the figure, in order to make the configuration of the polarizer unit 10 easy to understand, only the polarizer unit 10 is shown in the illuminator installation pedestal 4.

As shown in the figure, the polarizer unit 10 includes a plurality of unit polarizer units (first polarizers) 12, and a frame 14 in which the unit polarizer units 12 are aligned in a row in a row. The frame 14 is a frame-like frame in which the unit polarizer units 12 are connected to each other. The unit polarizer unit 12 includes a wire grid polarizer (polarizer) 16 formed in a substantially rectangular plate shape.

In the present embodiment, each unit polarizer unit 12 is formed such that the wire grid polarizer 16 is supported in a line direction A parallel to the linear movement direction X of the workpiece stage 5 so as to be orthogonal to the line direction A. It is aligned with the arrangement direction B of the wire grid polarizer 16.

The wire grid polarizer 16 is one of linear polarizers. 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 can be linearly polarized and transmitted even if it is obliquely incident.

The wire grid polarizer 16 is supported by the unit polarizer unit 12 so as to be rotatable in-plane with its normal direction as a rotation axis and finely adjust the direction of the polarization axis C1. By finely adjusting all of the unit polarizer units 12 so that the polarization axis C1 of the wire grid polarizer 16 is aligned in a predetermined irradiation reference direction, the entire length of the long-axis direction of the polarizer unit 10 can be obtained and the polarization axis can be obtained. C1 aligns the polarized light with high precision to achieve high-quality light alignment.

As shown in FIG. 1, the polarization measuring system 1 includes a polarization measuring device 20 and a measuring unit 30. The measuring unit 30 includes a detecting unit 31 that detects a polarized light, and the polarized light measurement The fixing device 20 measures the polarization axis of the polarized light and the extinction ratio based on the detection result of the polarized light obtained by the detecting unit 31.

As shown in FIG. 2, the measuring unit 30 includes a linear guide 32 that guides the detecting unit 31 in a straight line. In the measurement of the polarized light, the linear guide 32 is connected to the side surface 5A on the traveling direction side of the workpiece mounting table 5, and is transferred to the directly below the polarizer unit 10 or the linear guide 32 is positioned directly below the polarizer unit 10. It is placed on the stage transfer pedestal 3. Further, the detecting portion 31 is moved along the linear guide 32 or moved by itself so as to be positioned directly below the wire grid polarizer 16 of the fine adjustment target, and the detecting portion 31 detects that its position passes through the wire grid polarizer 16 The polarized light is used to measure the polarizing characteristics of the irradiated light.

FIG. 3 is a schematic view showing the configuration of the detecting unit 31.

The detecting unit 31 includes a detecting side polarizer (a second polarizer, a measuring polarizer) 33 and a light receiving sensor 34.

The detection-side polarizer 33 is a linear polarizer for detecting light in a plate shape (a disk shape in the illustrated example) of the polarization axis C2, and is also referred to as a deposition sheet. In the detection-side polarizer 33, a polarized ray F that is linearly polarized by the line-gate polarizer 16 is incident, and the polarized ray F is linearly polarized. As the detection side polarizer 33, any polarizer can be used as long as it is a linear polarizer, and for example, a wire grid polarizer can be used.

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 measuring device 20.

In the detecting unit 31, the detecting side polarizer 33 is provided to be freely rotatable by rotating at least one rotation continuously for one rotation direction in the normal direction S. The rotation of the detecting 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, the detecting unit 31 is attached to the linear guide 32 and the detecting side polarizer 33 is When the reference position P0 coincides, the polarization axis C2 of the detection side polarizer 33 is in a state of being directed toward the irradiation reference direction.

The polarization measuring device 20 measures the polarization axis of the polarized light F and the extinction ratio based on the periodic variation of the amount of light of the detection light G when the detection side polarizer 33 rotates for one week. 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 unit 25. Furthermore, the polarization measuring device 20 can also be implemented by, for example, a personal computer executing a computer readable program that implements the various parts shown in FIG. 2.

The rotation drive control unit 21 controls the rotation of the detection side polarizer 33 of the detection unit 31. Specifically, the detecting unit 31 includes a rotary actuator that rotates the detecting-side polarizer 33, and the rotational driving control unit 21 controls the rotary actuator to rotate the detecting-side polarizer 33, thereby causing the polarization axis C2 and the predetermined one. The direction of the rotation angle θ coincides. The rotation angle θ at this time is output to the change curve calculation unit 23.

The input unit 22 receives a means for inputting the detection value of the light amount I of the detection light G, and the detection unit 35 of the detection unit 31 is input to the input unit 22. The input unit 22 acquires the detected value of the light amount I of the detection light G from the detection signal 35, and outputs it to the change curve calculation unit 23.

The change curve calculation unit 23 calculates a change curve Q indicating a periodic change in the light amount I of the detection light G when the detection side polarizer 33 is rotated by one rotation, based on the detected value of the light amount I of the detection light G. As described in detail above, the detection light G is the light obtained by sequentially passing the emitted light E of the lamp 7 through the line-gate polarizer 16 as the linear polarizer and the detection-side polarizer 33, as shown in FIG. 3 disclosed above.

Therefore, the curve Q of the light amount I of the detection light G accompanying the rotation of the detection side polarizer 33 is desirably as shown in FIG. 4, and the polarization axis C2 as the detection side polarizer 33 is parallel to the wire grid polarizer 16. The case of the polarization axis C1 (in the present embodiment, the rotation angle θ =0°, 180° (maximum point)) is the maximum light amount Imax (maximum value) and is orthogonal to the polarization axis C2 and the polarization axis C1 (in the present embodiment, the rotation angle is θ=90°, 270° (very small) Point)) The cosine waveform represented by the following formula (1) in which one cycle is π[rad] (=180°) in the case of the minimum light amount Imin (minimum value) (so-called Law of Malus) .

Change curve Q=α×cos(β×(θ-γ))+ε (1)

Here, α is an amplitude, β is a period, γ is a phase deviation (a phase difference between a polarization axis C1 of the wire grid polarizer 16 and a reference position P0), and ε is a bias component.

However, the inventors and the like obtained the following findings regarding the variation curve Q through a keen experiment.

In other words, since the light aligning device 2 uses the lamp 7 as the discharge lamp as the light source, the brightness of the light source is caused by various factors such as the fluctuation of the lighting power of the power supply device that lights the lamp 7 or the cooling state of the lamp 7. Fluctuating or flickering occurs during a very short period of time, which becomes a noise component of the brightness of the light source.

Further, since the optical alignment device 2 illuminates the polarized light F from the lamp 7 through the polarizer unit 10 in a wide range, the polarized light F of various incident angles is incident on the light receiving sensor 34 of the detecting portion 31, and is adjacent to the adjustment. The polarized light F of the other wire grid polarizer 16 of the object's wire grid polarizer 16 is also incident and detected.

The variation curve Q obtained from the detection result of the detecting portion 31 due to the noise component of the brightness of the light source or the oblique incidence of the polarized light F is shifted from the ideal cosine function (formula (1) above). The n-th cosine waveform (n ≧ 2) shown by the following formula (2) is sufficiently approximated.

Change curve Q=α×cosn(β×(θ-γ))+ε (2)

According to the above findings, as the variation curve Q, it is preferable to obtain the n-th cosine waveform from the detection value of the amount of light of the detection light G. However, there is a problem that measurement and calculation of a large amount of detection light G are required.

Further, the extinction ratio divides the maximum light amount Imax by the minimum light amount Imin. Therefore, the smaller the minimum light amount Imin, the greater the influence of the noise component occupied by the minimum light amount Imin on the value of the extinction ratio, by the above (2) When the variation curve Q is obtained by the equation, since the accuracy of the minimum light amount Imin is poor, the extinction ratio cannot be accurately obtained.

Therefore, in order to obtain the required accuracy, it is only necessary to repeatedly determine the number of times or the number of measurement points for obtaining one change curve Q, and obtain the number of times of change Q and average them. There is a problem that the measurement takes time because the number of times of measurement becomes very large.

As a method for solving this problem, a process is considered in which a noise sensor of the brightness of the light source is removed from the detection signal 35 of the detecting unit 31, and a light receiving sensor provided separately from the detecting unit 31 is prepared, and the light receiving unit is additionally provided. The sensor detects the light amount I of the detection light G for reference, and removes the noise component from the detection signal 35 of the detecting unit 31 based on the detection result of the reference.

However, in the polarization measurement, generally, even if the light is transmitted through the optical element such as a mirror or a cymbal, the polarization state changes, so that the detection light G incident on the detecting unit 31 cannot be branched to a separately received light sensation. Detector. Therefore, the detection light G received by the light receiving sensor provided separately from the detecting portion 31 is different, so that the noise component is not accurately removed.

Further, the amount I of the detection light G detected by the light receiving sensor 34 of the detecting unit 31 changes in accordance with the rotation of the detecting side polarizing plate 33, and the amount of the noise component of the light source brightness also changes. Therefore, it is necessary to reflect the detection value of the separately received light sensor reflecting the rotation angle θ of the detection side polarizer 33. Further, when the light-receiving sensor 34 included in the detecting unit 31 is compared with a separately received light-receiving sensor, it is necessary to correct noise caused by the change in the sensitivity of the sensor or the temperature characteristic. The difference in the light receiving characteristics of the two.

As such, the measurement method using the separately provided light-receiving sensor includes a large number of problems that must be solved in order to achieve high-precision measurement.

Therefore, in the present embodiment, the detection value of the light amount I for fitting the curve of the variation curve Q is limited to be detected within the range W near the minimum point of the minimum light amount I of the detection light G as shown in FIG. Therefore, although the measurement is performed by one light receiving sensor 34, the variation curve Q having a high repeating accuracy can be calculated with a small number of measurement points.

As will be described in detail, if the ratio of the noise component of the light source luminance occupied by the light amount I of the detection light G is substantially constant, the magnitude of the noise component becomes larger in proportion to the light amount I of the detection light G. As shown in FIG. 4 as disclosed above, the size 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 amount of the light amount I due to the influence of the noise component of the light source luminance is smaller than the vicinity of the maximum light amount Imax.

Therefore, the detected value Q of the light amount I in the vicinity of the minimum light amount Imin which is less affected by the noise component is obtained, and the above-described change curve Q is obtained by curve fitting, whereby the influence of the fluctuation of the brightness of the light source or the like can be suppressed. The resulting curve of the noise component Q. Further, since the influence of the noise component of the light source luminance is suppressed, the repeating accuracy is improved, and even if the measurement is performed once, the reliability curve Q having a high reliability can be obtained.

The inventors of the present invention have obtained the following findings: a range of the vicinity of the minimum light amount Imin, and a range W of the rotation angle θ at which the light amount I of the detection light G becomes 20% or less of the maximum light amount Imax is based on the range The amount of light I of the detection light G measured by the rotation angle θ in W can be obtained by suppressing the influence of the noise component of the brightness of the light source and having a higher repeating accuracy curve Q. Further, the inventors obtained the following findings: if it is within a range of ±20° around the rotation angle θa at which the minimum light amount Imin is obtained, it is included in the above Range W.

According to these findings, in the present embodiment, as shown in FIG. 5, the light amount I of the detection light G is performed by the four-point rotation angle θ (θ=θa±10°, θa±20°) included in the range W. It is detected that the above-described change curve Q is obtained by curve fitting based on the light amount I at each rotation angle θ.

By shifting the rotation angle θ for detecting the amount of light I of the detection light G by about 10°, a significant difference between the detected values of the light amount I of the detection light G can be made, so that the difference between the detected values can be prevented from being hidden. Among the noise components of the luminance of the light source, the variation curve Q is surely obtained.

In addition, the rotation angle θ of the light amount I of the detection light G is not limited to four points, and may be at least three points or more in the range of the above range W.

The change curve calculation unit 23 obtains the equation (1) by curve fitting (also referred to as curve regression) based on the detected value of the light amount I of the detection light G when the rotation angle θ is included in the above range W. The cosine waveform shown is output to the polarization characteristic specifying portion 24.

When the polarization direction of the polarized light F is deviated from the direction of the reference position P0, that is, when the direction of the polarization axis C1 of the wire grid polarizer 16 deviates from the direction B which is the direction of the reference position P0, as shown in FIG. As indicated by the imaginary line, the deviation from the variation curve Q appears as a phase deviation γ (>0).

The polarization characteristic specifying unit 24 specifies the polarization direction of the polarization ray F (that is, the direction of the polarization axis C1 of the wire grid polarizer 16) and the extinction ratio based on the variation curve Q obtained by the variation curve calculation unit 23, and outputs the same. To the polarization characteristic output unit 25.

Specifically, as shown in FIG. 4, the polarization characteristic specifying unit 24 specifies the polarization axis C1 by specifying the above-described γ which is the rotation angle θ (maximum point) of the maximum light amount Imax of the detection light G in the variation curve Q. Direction, and specific extinction according to the ratio of the maximum light amount Imax of the variation curve Q to the minimum light amount Imin (=maximum light amount Imax/minimum light amount Imin) ratio. The maximum light amount Imax in the variation curve Q is obtained by substituting the rotation angle θ=γ (maximum point) into the variation curve Q, and the minimum light amount Imin is obtained by substituting the rotation angle θ=90°+γ (minimum point). Out.

The polarization characteristic output unit 25 outputs the polarization characteristics (polarization axis and extinction ratio) specified by the polarization characteristic specifying unit 24. The aspect of the output is arbitrary as long as the user can utilize the polarization characteristic, and examples thereof include display, output to another electronic device, recording to a recording medium, and the like.

Here, the rotation angle θa (minimum point) at which the minimum light amount Imin is obtained is as shown in FIG. 4 disclosed above, and is present in the phase during the rotation of the detection side polarizer 33 for one week (θ=0 to 360°). In the present embodiment, the change curve calculation unit 23 measures the four-point rotation angle θ in the range W for each of the two rotation angles θ=θa and θa+180°. The light amount I of the light G is detected to obtain two change curves Q, and the polarization characteristic specifying unit 24 obtains a polarization axis and an extinction ratio for each of the two change curves Q, and obtains an average value thereof, thereby improving polarization. The accuracy of the axis and the extinction ratio.

Further, in the present embodiment, in order to increase the detection accuracy of the light amount I of the detection light G at the four-point rotation angle θ in each of the above-described ranges W of the two rotation angles θ = θa and θa + 180°, the same rotation is performed. The angle θ is repeated several times (for example, 10 times) to measure the amount of light I.

As a result, as shown in FIG. 6, the detection value of M (M≧2) light amount I can be obtained for each of the same rotation angles θ. When the change curve Q is obtained from the detected values, the change curve calculation unit 23 selects N (M≧N≧1) detection values for each rotation angle θ, and obtains an average value of the N detection values, and The curve Q is obtained from the average values. Since the number of combinations of N selected from the M detection values is MCn, the change curve calculation unit 23 obtains the change curve Q for each of the MCn combinations. Further, the polarization characteristic specifying unit 24 The polarization axis and the extinction ratio are obtained for each of the MCn variation curves Q, and the average value of each polarization axis and each extinction ratio is obtained. Thereby, the polarization axis and the extinction ratio can be obtained with higher precision.

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

As shown in the figure, the polarization measuring device 20 controls the rotation of the detecting side polarizer 33 of the detecting unit 31 to match the rotation angle θ with the measurement point (step S1). In the present embodiment, the measurement point of the rotation angle θ is 8 points in total of θ = θa ± 20°, θa ± 10°, θa + 180° ± 20°, and θa + 180 ° ± 10° as shown in Fig. 6 . The rotation angle θa is an angle (minimum point) at which the minimum light amount Imin can be obtained, as shown in Fig. 4 disclosed above, which is specified by θa = 90° + γ. In the present embodiment, γ = 0 in a state where the polarization axis C1 is not deviated. Therefore, in the above-described step S1, the polarization measuring device 20 determines the measurement point of the rotational angle θ as θa = 90°.

Then, the polarization measuring device 20 intermittently takes in the detection signal 35 of the light amount I of the detection light G intermittently, and acquires the detected values of the M light amounts I (step S2).

The polarization measuring device 20 repeatedly performs the above-described steps S1 and S2 at all the measurement points of the rotation angle θ until the detection values of the M light amounts I are obtained (step S3: Yes).

The polarization measuring device 20 obtains the variation curve Q for using the detected value of the light amount I in the vicinity of the minimum light amount Imin (near the minimum point), and the light amount I at the four points according to the rotation angle θ = θa ± 20° and θa ± 10° The detected value is obtained by curve fitting to obtain a curve Q that follows the above formula (1) (step S4). When the details are described, the polarization measuring device 20 selects N (M≧N≧1) detection values for each of the rotation angles θ, and obtains an average value of the N detection values as the rotation angle θ. The value is detected and the curve Q is obtained by curve fitting. As described above, the MCn variation curves Q are obtained. Then, the polarization measuring device 20 obtains a polarization axis and an extinction ratio for each of the MCn variation curves Q, and obtains an average value of each polarization axis and each extinction ratio (step S5).

In the same manner as steps S4 and S5, the polarization measuring device 20 is based on the detection value of the light amount I at the four points of the rotation angle θ=θa+180°±20° and θa+180°±10°. The change curve Q is obtained in combination (step S6), and the polarization axis and the extinction ratio are specified based on the change curve Q (step S7).

Then, the polarization measuring device 20 determines the polarization axis of the polarized light and the extinction ratio by obtaining the average of the polarization axes and the extinction ratios obtained in steps S5 and S7 (step S8).

Thereby, the polarization axis of the polarized light and the extinction ratio can be obtained with high precision.

Further, in the measurement, the polarization measuring device 20 can specify the rotation angle θ=θa at which the minimum light amount Imin can be obtained, and the rotation angle θ=γ at which the maximum light amount Imax can be obtained, so that the detecting portion 31 can be used. The detection side polarizer 33 is rotated, and the light amount I of the detection light G is actually detected at each rotation angle θ, and the extinction ratio is obtained based on the detection value.

Further, in the above-described polarization measurement, even if the required precision is obtained without performing the processing of steps S6 to S8, the processing specified in step S5 may be omitted without performing the processing of steps S6 to S8. The polarization axis and the extinction ratio were used as the measurement results. Further, the user or the like can also select whether or not to perform the processing of steps S6 to S8.

Next, the measurement of the polarized light of the optical alignment device 2 using the polarization measuring system 1 will be described.

The worker first sets the measurement unit 30 to the optical alignment device 2. At the time of this setting, the operator sets the linear guide 32 such that the guiding direction of the linear guide 32 is parallel to the arrangement direction B of the wire grid polarizer 16 and directly below the polarizer unit 10. Then, the operator guides the detecting unit 31 by the linear guide 32 and arranges it under the wire grid polarizer 16 of the measurement target, and detects the polarized light F emitted from the wire grid polarizer 16 using the polarization measuring system 1 . Measuring the polarization axis C1 of the wire grid polarizer 16 and extinction ratio. According to the measurement result of the polarization axis C1, the operator finely adjusts the rotation of the wire grid polarizer 16 as needed, thereby matching the direction of the polarization axis C1 with the predetermined direction (the arrangement direction B in the present embodiment).

The operator performs the measurement of the polarized light F in the same manner for all of the wire grid polarizers 16 included in the polarizer unit 10, and based on the measurement result, the operation of matching the direction of the polarization axis C1 with the arrangement direction B is performed, thereby making all the lines The direction of the polarization axis C1 of the gate polarizer 16 is aligned in the arrangement direction B.

As described above, according to the polarization measuring system 1, the variation curve Q having high repetition accuracy and high reliability can be obtained without performing the same measurement several times, and the polarization axis C1 can be specified with high precision from the variation curve Q. The direction. Therefore, when the respective wire grid polarizers 16 are finely adjusted, the number of times of measurement of the polarized light F can be reduced, and the fine adjustment operation can be ended in a short time, and the direction of the polarization axis C1 can be adjusted with high precision.

In the optical alignment device 2, the radiation E of various angles radiated from the rod-shaped lamp 7 is incident on the wire grid polarizer 16, and is emitted by linearly polarizing the wire grid polarizer 16.

On the other hand, it has been known to use a Glan-Thomson polarizing ray for detecting a detecting portion of the side polarizer 33. However, in the detection unit using the Glan-Thomson polarization, the extinction ratio of the Glan-Thomson polarization is greatly changed by the incident angle, and therefore the incident angle incident on the detection portion must be minimized.

Therefore, in the conventional detecting unit, only the angular component of the range of the polarized light F including the various angular components outputted from the wire grid polarizer 16 can be detected, and the polarized light F cannot be accurately measured.

Therefore, in the present embodiment, by using the detecting unit 31 having the configuration described below, it is possible to detect a wide angle component even if it is a polarized ray F including various angular components. The polarization characteristics were measured.

8 is an external perspective view showing the configuration of the detecting unit 31, and FIG. 9 is a cross-sectional view of the detecting unit 31.

As shown in the above figures, the detecting unit 31 includes a rectangular plate-shaped base 70, and includes a light receiving sensor unit 71, a detecting side polarizing plate 33, a rotating mounting table 72, and a detecting light adjusting unit 73 (FIG. 9). ).

The photosensor unit 71 includes a photomultiplier tube 74 as an example of the photodetector 34, and the photomultiplier tube 74 is cooled to keep the temperature constant and reduce the noise caused by the temperature characteristics of the photomultiplier tube 74. The substrate 75 is water-cooled, and the detection signal 35 (Fig. 3) of the photomultiplier tube 74 is taken in by the polarization measuring device 20.

The base 70 is engaged with the linear guide 32 and linearly guided by the linear guide 32. By arranging one of the predetermined sides of the susceptor 70 in conformity with the long-axis direction of the linear guide 32, the reference position P0 and the polarization axis C2 of the detecting-side polarizer 33 are oriented toward the irradiation reference direction. Further, the linear guide 32 is not necessarily used if one of the predetermined sides of the susceptor 70 is provided to coincide with the irradiation reference direction.

The detecting side polarizer 33 is disposed directly above the detecting surface 74A of the photomultiplier tube 74, and covers the incident side of the detecting light G by the aperture 76 formed with the opening 76A of a predetermined diameter. The aperture 76 restricts the incident light toward the detecting side polarizer 33. However, in the detecting portion 31, oblique light is transmitted through the wire grid polarizer 16 to generate the polarized light F, and is also taken in accordance with the aperture The polarized light F of the component which is obliquely incident, and the opening 76A is formed by passing the polarized light F having an incident angle Y of 0° to 70°.

Further, the range of the incident angle Y is determined based on the shape or arrangement relationship of each of the detecting portion 31, the wire grid polarizer 16, and the lamp 7, and the component of the polarized light F radiated obliquely from the wire grid polarizer 16 is taken. Into the angle.

The detection light adjustment 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 cylindrical body 77 that is taken in through the aperture 76 and passed through the detection side polarizer. The detection light G of 33 is taken in from the upper surface of the cylinder 77, mixed internally, and introduced into the photomultiplier tube 74 from the lower surface.

Specifically, on the upper surface of the cylindrical body 77 of the detecting light adjusting unit 73, an aperture 78 is formed which is formed with an opening 78A through which the detection light G of the range of the incident angle Y taken in by the aperture 76 is passed. .

In the cylindrical body 77, in order to ensure a wide angle of incidence of the light and to cancel the polarization state of the taken light, the polarizing is performed, and the transmitted light is diffused without being separated by a gap directly below the aperture 78. Diffusion unit 79. The diffusion unit 79 includes two diffusion plates 79A and 79B that are disposed opposite to each other at a predetermined interval, and mix and output the detection light G of various incident angles Y. For the diffusion plates 79A and 79B, for example, a frost-type synthetic quartz plate is used.

On the lower surface of the cylindrical body 77, a plate member 80 having a pinhole 80A for restricting the amount of incident light toward the photomultiplier tube 74 is formed, and light passing through the pinhole 80A is incident on the detecting surface 74A of the photomultiplier tube 74.

Further, between the pinhole 80A and the detection surface 74A of the photomultiplier tube 74, a wavelength limiting filter 81 that cuts light having a wavelength other than the wavelength of the light distribution is provided, and the environment is limited by the wavelength limiting filter 81. The light-cut light is introduced into the photomultiplier tube 74.

In this manner, the detecting unit 31 is configured to take the polarized light F into a relatively large incident angle Y and diffuse it inside, and detect the amount of light by the photomultiplier tube 74. Therefore, even if it is made of a rod shape The polarized light E obtained by the light emitted from the lamp 7 through the wire grid polarizer 16 includes the polarized light F of various angular components, and the range of the wide angle component can be detected to measure the polarization characteristics.

As described above, according to the present embodiment, the following configuration is adopted: The detection of the light amount I at each rotation angle θ obtained by sequentially transmitting the detection light G of the wire grid polarizer 16 and the detection side polarizer 33 while rotating the detection side polarizer 33 is performed to determine the detection. The curve Q of the periodic variation of the amount of light I when the side polarizer 33 is rotated for one week is obtained by including the rotation angle θ=θa which is one minimum point of the variation curve Q and is included in the light amount I to be a predetermined value or less. (In the present embodiment, in the range W of the rotational angle θ of the maximum light amount Imax, the light amount I at each of the rotational angles θ = θa ± 20° and θa ± 10° is obtained, and the variation curve Q is obtained. .

In this way, the variation curve is obtained based on the detected value of the noise component included in the detected value as compared with the detected value of the light amount I in the vicinity of the maximum light amount Imax of the maximum point, so that the accuracy of the change curve is improved. . By obtaining the polarization characteristics from the change curve, the polarization characteristics can be accurately obtained.

Further, since only the amount of light I in the vicinity of the minimum light amount Imin which is the minimum point is measured, it is possible to perform measurement with high precision with a small number of measurement times.

Further, according to the present embodiment, the rotation angle θ is included in the rotation angle θ=θa+180° which is one of the minimum points different from the rotation angle θ=θa and is included in the rotation amount θ which is equal to or less than the predetermined value. In the range W, the light amount I at the rotation angle θ=θa+180°±20°, θa+180°±10°, and the variation curve Q is obtained, according to which the polarization characteristic of the polarization ray F is specified, and The polarization characteristic of the specific polarized light F is specified based on the average of the polarization characteristics specified by the variation curve Q corresponding to the range W including the above-described rotational angle θ = θa.

Therefore, when it is necessary to measure with high precision, the polarization characteristics of the polarized light F can be obtained with higher accuracy.

In the present embodiment, the range W is set such that the light amount I of the detection light G is within a range of about 20% of the maximum light amount Imax. The high-precision curve Q of the influence of the noise component.

Further, according to the present embodiment, the detecting unit 31 is configured to include an aperture 76 that takes in the polarized light F including the oblique incident component and enters the detecting side polarizing plate 33, and a diffusing unit 79 that transmits the detecting side polarizer The light diffusion of 33; and a photomultiplier tube 74 as a light-receiving sensor receives the light diffused by the diffusion unit 79 and detects the amount of light I.

Thereby, even if the polarized light F of various angle components is included in the polarized light F obtained by passing the emitted light E of the rod-shaped lamp 7 through the wire grid polarizer 16, the range of the wide angle component can be detected and measured. Polarized characteristics.

<Second embodiment>

Next, a second embodiment of the present invention will be described with reference to Fig. 10 or Fig. 14 .

In the first embodiment, the polarization axis C1 is measured for each of the wire grid polarizers 16. However, in the second embodiment, the polarization direction of the polarization light is measured for each position (measurement point) of the light alignment object. In the second embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals and will not be described.

Fig. 10 is a view showing the configuration of the optical alignment device 100 of the second embodiment.

The optical alignment device 100 includes a polarization measuring system 1 for preventing the uniformity of the irradiation light and preventing the escape from the alignment film during the processing of the light alignment object (in the process of irradiation). For the purpose of adhesion, as shown in FIG. 10, the wire grid polarizer 16 is disposed with a predetermined distance from the alignment film on the surface of the light-aligning object. The optical alignment device 100 is formed in the same manner as the optical alignment device 1 of the first embodiment except that the configuration of the polarization measuring system 1 and the distance between the wire grid polarizer 16 and the alignment film are provided.

Further, as described above, the incident light E of various angles radiated from the rod-shaped lamp 7 is incident. The wire grid polarizer 16 is emitted as a polarized light F by linearly polarizing the wire grid polarizer 16. Such polarized light F contains various angular components.

In this manner, the wire grid polarizer 16 is disposed with a predetermined distance from the alignment film of the surface of the light-aligning object, and the polarized light F includes various angular components, and thus the polarized light F of the plurality of wire grid polarizers 16 overlaps. The light is directed to the object of the light. The polarization characteristics of the polarized light F are not uniform due to the influence of the difference in characteristics or the incident angle due to the portion of the polarizer that passes through, and the polarized light F having various polarization characteristics is irradiated to the light-aligning object.

For example, in the present embodiment, when the illumination distribution in the longitudinal direction of the lamp 7 directly under the illuminator 6 is separated for each of the wire grid polarizers 16 (n-3 to n+1), it is as shown in FIG. In the curve, the amount of illumination light at a certain irradiation position (0 mm) is affected by the amount of illumination light at three irradiation positions on both sides. As shown in Fig. 11, even when the center of the wire grid polarizer 16 is directly below, as the irradiation light, the amount of light passing through the wire grid polarizer 16 directly above is the total amount of light passing through the surrounding wire grid polarizer 16. One and a half of the amount of light.

Further, the structural members such as the polarizer unit fixing base 9 of the frame 14 and the fixed frame 14 are formed of a light shielding member, or are covered by a light shielding member to constitute a light shielding member. However, reflection of the structural member such as the frame 14 or the polarizer unit fixing table 9 cannot be completely prevented, and as shown in FIG. 12, the reflected light H reflected by the structural member also becomes scattered light and is incident on the workpiece mounting table 5 Object T. The polarization characteristics of the polarized light F also vary depending on the reflection. Further, the reflected light H also includes light reflected by the alignment film of the surface of the object T and then reflected by the wire grid polarizer 16 and the like.

Therefore, for example, when the angle of incidence of the detection light of the detecting unit 31 is narrowed and the polarization axis C1 is measured for each of the wire grid polarizers 16, the polarized light F of the wire grid polarizer 16 other than the measurement target cannot be obtained. Or the reflected light H is measured. the result, The polarization characteristics of the illumination light actually irradiated to the light-aligning object can not be accurately measured.

Therefore, in the present embodiment, the detection unit 31 that takes in the polarized light F and diffuses the inside and uses the photomultiplier tube 74 to detect the amount of light by using the range of the relatively large incident angle Y can detect a wider range. The polarization characteristics (polarization direction, extinction ratio) of the polarized light F (irradiation light) actually irradiated to the light-aligning object are measured in the range of the angle component.

Further, the detection light G received by the detecting unit 31 is the light obtained by sequentially passing the emitted light E of the lamp 7 through the line-gate polarizer 16 as the linear polarizer and the detecting-side polarizing plate 33, and is a plurality of wire grid polarized lights. The light of the polarized light of the sheet 16 coincides. In other words, the phase deviation γ is obtained as the phase difference between the polarization direction of the polarized ray F and the reference position P0. Further, since the detection light G includes a plurality of polarization ray beams or reflected light of the wire grid polarizer 16, the polarization direction and the extinction ratio of the polarization ray are distributed, and the polarization direction and the extinction ratio of the polarization ray are obtained according to the peak value of the distribution. Out.

In other words, the wire grid polarizer 16 is formed of a material such as glass and is a relatively easily damaged optical component. Therefore, it is held by the frame 14 via a cushioning material (not shown). More specifically, the wire grid polarizer 16 whose polarization axis C1 is adjusted is fixed to the frame 14 by screws (fixing means) 19 at the upper end and the lower end of the unit polarizer unit 12 as shown in FIG. Frame 14. The deterioration of the buffer material of the wire grid polarizer 16 or the vibration of the light alignment device 100 causes the positional shift of the wire grid polarizer 16 to occur, and as a result, the polarization direction of the polarized light is shifted.

Further, in the treatment of the light-aligning object (during irradiation), there is a case where the gas is generated from the alignment film, and if impurities such as outgas are mixed in or adhered to the wire grid polarizer 16, the polarization characteristics of the wire grid polarizer 16 are obtained. Will change.

In the optical alignment device 100 of the present embodiment, the polarization characteristics are not always measured by the polarization measuring system 1, but the polarization characteristics are changed due to deterioration over time or outgas. The polarizing characteristics were measured after a predetermined period of time, for example, one month later.

Next, the measurement of the polarized light of the optical alignment device 100 will be described with reference to FIG. 14.

Fig. 14 is a schematic view showing the polarization axis adjusting device D.

The polarization axis adjustment device D includes a polarization measuring system 1A and a point light source 7A, and adjusts the direction of the polarization axis C1 of the wire grid polarizer 16. The polarization measuring system 1A has the same configuration as the polarization measuring system 1 except that the opening (not shown) of the detecting unit 31A is formed to be narrower than the opening 76A of the detecting unit 31 of the polarization measuring system 1. In FIG. 14, the same portions as those of the optical alignment device 100 are denoted by the same reference numerals, and description thereof will be omitted.

The operator first arranges the polarizer unit 10 at the polarization axis adjusting device D at another position. Next, the operator arranges the detecting unit 31A of the polarization axis adjusting device D directly under the wire grid polarizer 16 to be measured, and arranges the point light source 7A directly above the wire grid polarizer 16 to be measured. 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. According to the measurement result of the polarization axis C1, the operator finely adjusts the rotation of the wire grid polarizer 16 as needed, thereby matching the direction of the polarization axis C1 with the predetermined direction (the irradiation reference direction in the present embodiment).

The operator performs the measurement of the polarized light F in the same manner for all of the wire grid polarizers 16 included in the polarizer unit 10, and based on the measurement result, the operation of matching the direction of the polarization axis C1 with the irradiation reference direction is performed, thereby making all the lines The direction of the polarization axis C1 of the gate polarizer 16 is aligned in the irradiation reference direction.

Then, the operator sets the adjusted polarizer unit 10 to the optical alignment device 100, and instructs the polarization measuring system 1 to start the measurement of the polarization characteristics (polarization direction, extinction ratio). The polarization characteristics are determined by several measurement points in the arrangement direction B of the wire grid polarizer 16 The measurement is performed by the operator and stored in the polarization measuring system 1.

In the polarization measuring system 1, the detecting unit 31 is guided by the linear guide 32 and placed at a predetermined measurement point, and the polarized light F emitted from the wire grid polarizer 16 is detected, and the polarization direction and the extinction ratio are measured. The polarization measuring system 1 outputs the polarization ray F to all the measurement points, and outputs the result and the determination of the pass or fail to the polarization characteristic output unit 25. The judgment value of the pass or fail is also set by the operator and is stored in the polarization measuring system 1.

As described above, according to the optical alignment device 100, since the polarized light that is actually irradiated onto the light-aligning object is measured, the polarization direction of the polarized light can be specified with high precision. In the light alignment device 100, the polarization characteristics of the light-aligning object are indicative of the performance of the light-aligning device 100, and are the main factors determining the quality of the alignment film to be aligned by the polarized light. Therefore, it is important to grasp the characteristics.

When the operator determines that the polarization characteristics of all the measurement points satisfy the standard, the measurement is completed, and the polarization axis C1 of the wire grid polarizer 16 is adjusted in the polarization axis adjusting device D even when the polarization characteristic of one of the measurement points does not satisfy the reference. Or the direction of the polarizer unit 10 is maintained. Further, since the wire grid polarizer 16 is fixed to the frame 14 by the screw 19 after the adjustment, the polarization axis C1 of the wire grid polarizer 16 is disposed in the arrangement from the polarization axis adjusting device D toward the optical alignment device 100 and the like. The direction will not change.

As described above, according to the present embodiment, the polarization measuring system 1 is provided. The polarization measuring system 1 detects the workpiece mounting table that is irradiated by overlapping the polarized rays of the plurality of wire grid polarizers 16 arranged in a row. 5 The direction of polarization of the light of the position. According to this configuration, the polarization characteristics of the polarized light that is actually irradiated onto the alignment film disposed on the surface of the light-aligning object placed on the workpiece mounting table 5 can be detected, so that the polarization direction can be accurately measured.

Moreover, according to the present embodiment, the polarization measuring system 1 is provided with a detecting unit. In the configuration of 31, the detecting portion 31 is provided to be movable in the arrangement direction of the unit polarizer unit 12. According to this configuration, the polarization characteristics of the measurement points in the arrangement direction of the unit polarizer unit 12 can be measured. Therefore, the polarization characteristics of each position irradiated to the optical alignment object can be obtained in detail by narrowing the interval between the measurement points. .

Further, according to the present embodiment, the detecting unit 31 is configured to include an aperture 76 that takes in the polarized light F including the oblique incident component and enters the detecting side polarizing plate 33, and a diffusing unit 79 that transmits the detecting side polarizer The light diffusion of 33; and a photomultiplier tube 74 as a light-receiving sensor receives the light diffused by the diffusion unit 79 and detects the amount of light I.

Therefore, even if the polarized light F of various angle components is included in the polarized light F obtained by passing the emitted light E of the rod-shaped lamp 7 through the wire grid polarizer 16, the range of the wide angle component can be detected and measured. Polarized characteristics.

It is to be noted that the above-described embodiments are merely illustrative of one embodiment of the present invention, and may be arbitrarily modified and applied without departing from the spirit and scope of the invention.

For example, in the above-described embodiment, the light source 7 as the discharge lamp is exemplified as the light source of the polarized light measured by the polarization measuring system 1. However, the light source is not limited thereto and is arbitrary. That is, the present invention can be applied to the measurement of linearly polarized polarized light obtained by transmitting light of any light source through a polarizer. Also, the light source is not necessarily a linear light source.

Further, for example, in the above-described embodiment, the wired gate polarizer 16 is exemplified as an example of a polarizing plate that obtains a polarized light to be measured, but the polarizing plate is not limited thereto. In other words, the polarizer may be any one as long as it is a polarizer that can obtain a polarized light that is linearly polarized.

Further, for example, in the above-described embodiment, the polarization measuring device 20 is configured to measure the polarization axis (or the polarization direction) of the polarized light and the extinction ratio, but only one of them may be measured. Further, the polarization measuring device 20 can measure other characteristics such as light intensity in addition to the polarization axis (or polarization direction) of the polarized light and/or the extinction ratio.

In the above-described embodiment, the polarization measuring device 20 obtains the amount of light of the detection light G by inputting the detection signal 35 of the detecting unit 31 to the polarization measuring device 20, but the configuration is not limited thereto. In other words, the recording data in which the rotation angle θ and the amount of the detection light G are recorded may be acquired from, for example, another electronic device or a recording medium (for example, a semiconductor memory or the like).

Further, in the above-described embodiment, the detecting unit 31 is provided so as to be movable in the arrangement direction B of the unit polarizer unit 12. However, the detecting unit 31 is not limited thereto. For example, the detecting unit 31 can also move in the moving direction of the stage.

Claims (10)

A method for measuring a polarized light, comprising: a first step of detecting a second polarizer while rotating the light of the first polarizer and the second polarizer in sequence; a change curve indicating a periodic change of the amount of light of the second polarizer at the time of rotation of each of the rotation angles; and a second step of the curve obtained according to the first step a polarization characteristic of the polarized light that is transmitted through the first polarizer; and in the first step, the one of the minimum angles including the change curve is included in the range of the rotation angle in which the light amount is equal to or less than a predetermined value. The above-described change curve is obtained at the above-described amount of light of the rotation angle. The polarized light measuring method according to the first aspect of the invention, further comprising: a third step of including a minimum point different from the first step and included in the range of the rotation angle in which the amount of light is equal to or less than a predetermined value The change curve is obtained by the light amount of the rotation angle; and the fourth step is to specify a polarization characteristic of the polarized light transmitted through the first polarizer according to the change curve obtained in the third step; and In the fifth step, the polarization characteristics of the polarized light transmitted through the first polarizer are specified based on an average of the polarization characteristics specified in each of the second step and the fourth step. The polarized light measuring method according to claim 1 or 2, wherein the predetermined value is a light amount of about 20% of a maximum value of the light amount. The method for measuring polarized light according to item 3 of the patent application is based on the change corresponding to the above The rotation angle of the maximum value of the amount of light indicated by the curve specifies the polarization axis of the polarized light transmitted through the first polarizer, and/or the first polarizer is specifically transmitted through the maximum value and the minimum value indicated by the change curve. The extinction ratio of the polarized light. The method for measuring polarized light according to claim 1 or 2, wherein the polarization axis of the polarized light transmitted through the first polarizer is specifically determined according to a rotation angle corresponding to a maximum value of the amount of light indicated by the change curve, and/or The extinction ratio of the polarized light transmitted through the first polarizer is specified based on the maximum value and the minimum value indicated by the change curve. A polarization measuring apparatus comprising: a change curve calculating means obtained by detecting a second polarizer while rotating the light of the first polarizer and the second polarizer in sequence; A change curve indicating a periodic change of the amount of light when the second polarizer is rotated at a rotation angle of each of the rotation angles, and a polarization characteristic specifying means for specifically transmitting the first through the change curve a polarization characteristic of the polarized light of the polarizer; and the change curve calculation means is configured to include the light amount at the rotation angle in a range including the minimum angle of the change curve and the rotation angle below a predetermined value And the above curve is obtained. A polarization measuring system comprising: a detecting unit that includes a second polarizer on which a polarized light that is polarized by the first polarizer is incident, and detects the transmission of the second polarizer while rotating the second polarizer; And a polarization measuring device that specifies a polarization characteristic of a polarized light transmitted through the first polarizer based on a detection result of the detecting unit; The detecting unit includes an aperture that takes in the light including the oblique incident component and causes the light to enter the second polarizer, and a diffusion means that diffuses the light transmitted through the second polarizer; and the light receiving sensor And receiving the light diffused by the diffusion means to detect the amount of light; and the polarization measuring apparatus includes: a curve calculation means for determining the amount of light of each of the rotation angles of the second polarizer; a change curve indicating a periodic change of the amount of light of the second polarizer at the time of rotation; and a polarization characteristic specifying means for specifying a polarization characteristic of a polarized light transmitted through the first polarizer according to the change curve; and the change The curve calculation means obtains the change curve based on the amount of light at the rotation angle included in the range of the rotation angle in which the light amount is equal to or less than a predetermined value, including one minimum point of the change curve. A light alignment irradiation device comprising a polarizer unit that irradiates a polarizing ray to an alignment film placed on a surface of a workpiece of a mounting table, wherein the polarizer unit is provided with a plurality of rows arranged neatly in a horizontal row In the unit polarizer unit, each of the unit polarizer units includes a polarizer, and the light alignment device includes light for a position corresponding to the mounting table that is irradiated by the polarized light passing through the plurality of polarizers. Detection means for detecting polarization characteristics. The optical alignment illuminating device of claim 8, wherein the detecting means is provided to be movable in an arrangement direction of the unit polarizer unit Detection department. The optical alignment illuminating device according to claim 8 or 9, wherein the detecting means includes a detecting portion that detects the light transmitted through the measuring polarizer while rotating the measuring polarizer And a polarization measuring device that specifies a polarization characteristic of light at a position corresponding to the mounting table based on a detection result of the detecting unit; and the detecting unit has an aperture that is disposed at a position corresponding to the mounting table and is taken in and passed through The polarized light of the plurality of polarizers generates overlapping light and is incident on the measuring polarizer; the diffusing means diffuses light transmitted through the measuring polarizer; and the light receiving sensor receives the light The light that has been diffused by the diffusion means detects the light amount, and the polarization measuring device includes a change curve calculating means for determining the measurement amount based on the light amount of the light at each rotation angle of the measuring polarizer. a variation curve of the periodic variation of the amount of light when the polarizer is rotated; and a specific means of polarization characteristics, According to the curve, the mounting table is quite specific polarization characteristic of the position of the irradiation light.