CN103477206A - Optical anisotropic parameter measurement device, measurement method and measurement program - Google Patents

Abstract

The object of the present invention is to reduce the size of the entire device by irradiating incident light perpendicularly to the sample, and at the same time measure the direction of the optical axis and the magnitude of the anisotropy in a very short time. The optical anisotropy parameter measurement device of the present invention is formed with a laser (6) that irradiates the incident light to the sample (3) in the vertical direction and guides the reflected light reflected in the vertical direction through the half mirror (7). To the measuring optical system (4) of the light-receiving element (9), a polarizer (P) is arranged between the laser (6) and the half-mirror (7), and between the half-mirror (7) and the light-receiving element Dispose photodetector (A) between (9), dispose between half mirror (7) and sample (3): 1/2 wavelength plate (12), make the polarizer (P) produce The linearly polarized light rotation; and 1/4 wavelength plate (13), the direction of slow phase axis is deviated from the slow phase axis relative to 1/2 wavelength plate (12) ± δ (δ ≠ nπ/4, n is an integer) and is synchronously driven to rotate so that the rotation angle becomes twice that of the 1/2 wavelength plate (12).

Description

Optical anisotropy parameter measuring device, measuring method and measuring program

technical field

The invention relates to an optical anisotropy parameter measuring device, a measuring method and a measuring program for measuring the orientation of the optical axis of a sample with optical anisotropy and the size of the anisotropy, and is especially suitable for the inspection of liquid crystal alignment films, etc. .

Background technique

The liquid crystal display is formed as follows: a rear glass substrate on which a transparent electrode and an alignment film are laminated on the surface, and a front glass substrate on which a color filter film, a transparent electrode, and an alignment film are laminated on the surface, and a spacer is interposed (spacer) Alignment films facing each other are sealed with liquid crystals sealed in gaps between the alignment films, and polarizing filter films are laminated on both front and back sides.

Here, in order to make the liquid crystal display work normally, the liquid crystal molecules need to be uniformly arranged in the same direction, and the orientation of the liquid crystal molecules is determined by the alignment film.

The reason why the alignment film can arrange the liquid crystal molecules neatly is because it has molecular alignment. As long as the alignment film has uniform molecular alignment covering its entire surface, it is not easy to cause defects in the liquid crystal display, and as long as the uneven molecular alignment exists, The direction of the liquid crystal molecules will be disordered, and the liquid crystal display will become a defective product.

That is, the quality of the alignment film will directly affect the quality of the liquid crystal display. As long as the alignment film is defective, the directionality of the liquid crystal molecules will be disordered, so defects will also occur in the liquid crystal display.

Therefore, when assembling a liquid crystal display, as long as the alignment film is pre-checked for defects and only an alignment film with stable quality is used, the yield of the liquid crystal display is improved, and the production efficiency is improved.

Therefore, there is a need to easily measure the direction of the optical axis of the optical anisotropy or the size of the anisotropy caused by the molecular alignment of the alignment film. The applicant proposes a high-speed measurement of the optical anisotropy caused by the molecular alignment. tropism method (see Patent Document 1).

This method is a method of obliquely irradiating incident light to a sample such as a liquid crystal alignment film, and detecting the polarization state of the reflected light. Based on the reflected light intensity obtained by rotating the optical system or the sample stage (stage), It has the advantages of high sensitivity to anisotropy and short measurement time.

However, in an optical system that irradiates light at a predetermined incident angle from an oblique direction, since the reflected light is reflected at the same reflection angle as the incident angle, it is necessary to ensure that the optical paths of the incident light and reflected light are at two angles with respect to the measurement center. On the side, there is a problem of increasing the size of the measuring device.

Furthermore, when the optical system is rotated, it is also necessary to secure a circular space serving as an operating region corresponding to the radius of rotation, and thus a larger installation space is required.

In particular, the size of the mother glass of liquid crystal displays is about 2m on one side even for small and medium-sized liquid crystal displays, and more than 3m on one side of mother glass for large liquid crystal displays. In order to measure within a limited time, it is necessary to arrange a plurality of measuring devices in a one-dimensional or matrix form, so it is required to miniaturize the measuring devices.

Therefore, if the optical anisotropy parameter is measured by irradiating light perpendicularly to the measurement surface of the sample, the size of the device can be realized, and such a measurement device has also been proposed (see Patent Document 2).

Fig. 11 shows the explanatory diagram of this measuring device 31, and it is formed to irradiate the sample 34 in the vertical direction with the incident light reflected by the half mirror 33 from the laser 32 which becomes the light source, and irradiates the sample 34 in the vertical direction. The directionally reflected reflected light passes through the half mirror 33 and is guided to the optical path of the light receiving element 35, and since the incident light is not irradiated obliquely, the size of the device 31 can be reduced.

In this measuring device 31, a fixed polarizer P is arranged between a laser 32 and a half mirror 33, and a photodetector A is rotatably arranged between the half mirror 33 and a light receiving element 35, and the Between the half mirror 33 and the sample 34, a 1/2 wavelength plate 36 for rotating the linearly polarized light generated by the polarizer P is rotatably provided.

At this time, if the 1/2 wavelength plate 36 is rotated by 180°, the incident azimuth of the linearly polarized light irradiated on the sample 34 will be rotated by 360°. By rotating the photodetector A by 360°, it is possible to detect the polarization state of the reflected light when the incident orientation of the linearly polarized light irradiated on the sample is changed every 10°.

Then, for example, if the photodetector A is rotated every 10° to measure the reflected light intensity, then 36 data can be obtained on the relationship between the rotation angle θ of the photodetector A and the reflected light intensity R, and Fourier transform ( Fourier) analysis, then a phase difference data of the linearly polarized light relative to the incident azimuth ψ can be obtained at this time.

However, in order to obtain the phase difference data of linearly polarized light from 0° to 360° with respect to the incident azimuth, it is necessary to measure 36 points from 0° to 180° while stopping the 1/2 wavelength plate 36 every 5°, for example. The photodetector A is rotated 360° relative to this one angle and 36 data are obtained for every 10°. Therefore, it is necessary to rotate the photodetector A 36 times to obtain a total of 36×36=1296 points of data. Not only is the measurement time-consuming , and the subsequent calculation process is also time-consuming, and cannot be integrated into the actual production line.

If the 1/2 wavelength plate 36 is stopped every 10° and the data is acquired for every 10° of the photodetector A, the number of data will be reduced to 1/4 and become 18×18=324, but as a result, the photodetector A must still Rotate 18 times, so the measurement time is only reduced by about 1/2, and there will be a problem that the measurement accuracy will decrease as the number of data decreases.

[Prior Art Literature]

Patent Document 1

Patent Document 1: Japanese Patent Laid-Open No. 2008-76324

Patent Document 2: Japanese Patent Application Laid-Open No. 11-304645

Contents of the invention

Therefore, the technical subject of the present invention is to measure the direction of the optical axis and the magnitude of the anisotropy in a very short time while reducing the size of the entire device by irradiating the incident light perpendicularly to the sample.

In order to solve the above problems, the present invention provides an optical anisotropy parameter measuring device, which measures the direction of the optical axis of the sample based on the change of the polarization state of the incident light irradiated to the measurement area of the sample and the reflected light thereof. The size of the optical anisotropy, the optical anisotropy parameter measuring device is characterized in that it includes: a measuring optical system, from the laser that becomes the light source through the half mirror, the incident light is irradiated to the above-mentioned measurement area in the vertical direction, and from The reflected light reflected in the vertical direction of the measurement area is guided to the light receiving element through the above-mentioned half mirror; and the calculation processing device calculates the optical anisotropy parameter based on the reflected light intensity detected by the light receiving element. A polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, and a photodetector is arranged between the half-mirror and the light-receiving element, and between the half-mirror and the sample is arranged: 1/2 a wave plate that is rotationally driven in order to rotate the linearly polarized light generated by the above polarizer; and a 1/4 wave plate that shifts the direction of the slow axis relative to the slow axis of the above 1/2 wave plate by ± From the initial position of δ, it is rotated and driven synchronously so that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, δ≠nπ/4, n is an integer, and the above-mentioned arithmetic processing device calculates that the 1/4 wavelength The reflected light intensity R(+δ) detected when the plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ, and the 1/4 wavelength plate is synchronized with the 1/2 wavelength plate from the initial position -δ The difference ΔR of the reflected light intensity R(-δ) detected when the ground rotates determines the direction of the optical axis of the sample and the value of the optical anisotropy based on the relationship between the rotation angle of the linearly polarized light and the above difference ΔR. size.

The optical anisotropy parameter measurement device according to the present invention includes a measurement optical system that irradiates incident light from a laser as a light source to the above-mentioned measurement area in a vertical direction through a half-mirror, and irradiates the measurement area from the measurement area. The reflected light reflected in the vertical direction is guided to the light receiving element via the half mirror.

Therefore, the incident light is irradiated to the sample in the vertical direction, and compared with the case of irradiating the incident light from an oblique direction, not only can the device be miniaturized, but also the optical system does not need to be rotated, so no space is required.

The light irradiated from the laser becomes linearly polarized light through a polarizer, and the polarization axis of the linearly polarized light is rotated by a 1/2 wavelength plate, and converted into an ellipse by a 1/4 wavelength plate arranged to shift the slow axis by ±δ Polarized light is irradiated on the sample in the vertical direction.

Among the polarized light components contained in the reflected light, the polarized light component whose polarization state has not changed returns to linearly polarized light when it passes through the 1/4 wavelength plate again, and returns to the polarization axis at the time point of passing through the 1/2 wavelength plate. The linearly polarized light that is equal to the linearly polarized light generated by the polarizer is cut by the photodetector that has a crossed Nicol relationship with the polarizer. In contrast, the polarized light whose polarization state has changed Since the component is in a different polarization state from the original linearly polarized light, it passes through the photodetector and reaches the light receiving element, where it can be detected as a change in light intensity.

Since the reflected light from the sample surface having optical anisotropy changes in the polarized light component, a change in light intensity corresponding to the anisotropy is detected.

In actual measurement, the reflected light intensity R(+δ) detected when the 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ, and the 1/4 wavelength plate is rotated from the initial position The reflected light intensity R(-δ) detected when -δ is rotated synchronously with the 1/2 wavelength plate is measured.

That is, for one measurement point, for two times when the initial position of the 1/4 wavelength plate is +δ and -δ, only the 1/2 wavelength plate is rotated by 180°, and the 1/4 wavelength plate Rotate 360° to complete the measurement.

Next, the difference in reflected light intensity ΔR=R(+δ)−R(−δ) is calculated.

That is, by taking the difference in the polarization state included in the reflected light of the two elliptically polarized lights in a symmetrical relationship, only the change in the polarization state caused by the optical anisotropy of the sample can be extracted.

Then, the direction of the optical axis of the sample and the size of the optical anisotropy can be determined according to the relationship between the rotation angle of the linearly polarized light and the difference ΔR.

For example, if a graph with the rotation angle of linearly polarized light as the X axis and the difference as the Y axis is drawn, and the rotation angle is the direction of the optical axis of the sample, since the difference △R is 0, the rotation angle can be read Then the direction of the optical axis of the sample can be known.

In addition, since the size of the anisotropy will be reflected in the amplitude of the height direction of the difference △R, the size of the optical anisotropy can be judged according to the maximum or minimum value of the difference, which can be very simple and in a short time These optical anisotropy parameters are measured over time.

In addition, the difference at this time exhibits a change approximate to a sinusoidal curve with a cycle of 180°, and takes a value of 0 every 90°. This is because when the direction of the optical axis of the sample is set to 0°, the reflected light intensity becomes equal at 0° and 180°, and the reflected light intensity becomes equal at 90° and 270°.

Therefore, the orientation of the optical axis cannot be determined from this data alone.

However, for example, the product test of the liquid crystal alignment film is used to confirm the distribution state of the alignment direction (direction of the optical axis) in a plurality of measurement points, or the deviation from the direction of the alignment treatment, and the approximate alignment direction by the alignment treatment is It is known that the maximum offset is about 20°, so there is no possibility of mistaking the direction of the optical axis as 90°.

Description of drawings

FIG. 1 is an explanatory diagram showing an example of an optical anisotropy parameter measuring device according to the present invention.

FIG. 2 is an explanatory diagram showing the processing procedure thereof.

3(a) to 3(c) are graphs showing the results of measurements performed by the method of the present invention.

FIG. 4 is a graph showing the distribution of the direction of the optical axis.

FIG. 5 is a graph showing the distribution of the magnitude of anisotropy.

6(a) to 6(g) are graphs showing measurement results by another method according to the present invention.

7(a) to 7(d) are graphs showing measurement results by another method according to the present invention.

8(a) to 8(c) are graphs showing measurement results by another method according to the present invention.

FIG. 9 is an explanatory diagram showing another optical anisotropy parameter measuring device according to the present invention.

FIG. 10 is an explanatory diagram showing still another optical anisotropy parameter measuring device according to the present invention.

FIG. 11 is an explanatory diagram showing a conventional device.

Description of main component symbols

1 optical anisotropy parameter measuring device; 2 mounting table; 3 sample; S measuring point (measurement area); 4 measuring optical system; Polarizer; A photodetector; 10 two-dimensional light position detection elements; 121/2 wavelength plate; 131/4 wavelength plate; 14 object-side condenser lenses; 17 detection-side condenser lenses; 18 pinholes.

Detailed ways

In order to realize the miniaturization of the whole device by irradiating the incident light perpendicularly to the sample, and at the same time measure the direction of the optical axis and the magnitude of the anisotropy in a very short time, the present invention is equipped with: a measurement optical system, from becoming The laser of the light source irradiates the incident light to the above-mentioned measurement area in the vertical direction through the half-mirror, and guides the reflected light reflected from the measurement area in the vertical direction to the light-receiving element through the above-mentioned half-mirror; and an arithmetic processing device , the optical anisotropy parameter is calculated based on the reflected light intensity detected by the light receiving element.

The measurement optical system is equipped with a polarizer between the laser and the half mirror, and a photodetector between the half mirror and the light receiving element, and between the half mirror and the sample: 1 The /2 wavelength plate is rotationally driven in order to rotate the linearly polarized light generated by the polarizer; and the 1/4 wavelength plate shifts the direction of the slow axis from the slow axis with respect to the aforementioned 1/2 wavelength plate The initial position of ±δ (δ≠nπ/4, n is an integer) is synchronously driven to rotate so that the rotation angle becomes twice that of the 1/2 wavelength plate.

The arithmetic processing device calculates the reflected light intensity R(+δ) detected when the 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ, and the reflected light intensity R(+δ) when the 1/4 wavelength plate is rotated from the initial position -δ The difference ΔR of the reflected light intensity R(-δ) detected when the 1/2 wavelength plate is rotated synchronously, and the optical axis of the sample is determined from the relationship between the rotation angle of the linearly polarized light and the above difference ΔR direction and magnitude of optical anisotropy.

(Example 1)

An optical anisotropy parameter measurement device 1 of this example shown in FIG. 1 is a device for detecting an optical anisotropy parameter at a measurement point (spot-like measurement area) S provided on a sample 3 on a stage 2 .

The optical anisotropy parameter measuring device 1 is used to measure the direction of the optical axis and the magnitude of the optical anisotropy in the measuring point S based on the change of the polarization state of the incident light irradiated to the measuring point S and the reflected light The device is equipped with a measuring optical system 4 for analyzing the polarized light and an arithmetic processing device 5 such as a computer.

In the measurement optical system 4, there are formed: the incident light path L ₁ that irradiates the incident light to the measurement area S in the vertical direction from the laser 6 used as the light source through the half mirror 7; The reflected light is branched through the half mirror 7, and the half mirror 8 makes it branch and is guided to the reflected light path L ₂ of the light receiving element 9; and the light passing through the half mirror 8 is guided to two The swing detection optical path L ₃ of the optical position detection element 10 .

In the incident light path _L1 , between the laser 6 and the half mirror 7, a beam expander 11 and a polarizer P for amplifying the irradiated light and making it a parallel beam are disposed, and between the half mirror 7 Arranged between the stage 2 and the stage 2 are: a 1/2 wavelength plate 12, which is rotationally driven by a motor _M1 in order to rotate the linearly polarized light generated by the polarizer P; and a 1/4 wavelength plate 13, which makes the slow axis The direction is shifted from the initial position of +δ (δ≠nπ/4, n is an integer) relative to the retardation axis of the above-mentioned 1/2 wavelength plate 12 so that the rotation angle is doubled with respect to the 1/2 wavelength plate 12 Rotationally driven synchronously by the motor _M2 .

In addition, between the 1/4 wavelength plate 13 and the stage 2, the motor _M3 is rotatable and the incident light is passed through the motor M in such a manner that the focal point is connected to the surface of the sample 3 through the object-side condenser lens 14. ₄ A revolver (revolver) 16 is arranged so as to be movable up and down. This revolver 16 is equipped with an object-side condenser lens 14 for converging incident light, and is formed with a through hole 15 for passing incident light in a parallel light state. .

In this example, the laser 6 is a semiconductor laser with a wavelength of 532nm and a light intensity of 10mW, and is enlarged into a parallel beam with a diameter of 5mm by a beam expander 11 with a magnification ratio of 10 times, and passes through a grid with an extinction ratio of ^10-6 . The polarizer P of the Glan-Thompson prism passes through the condenser lens (manufactured by Olympus: magnification: 50 times) on the object side, and irradiates the sample.

At this time, the irradiation spot system for the sample is about 1 micron.

In the reflected light path _L2 , the photodetector A is arranged between the half-mirror 7 and 8, and between the half-mirror 8 and the light-receiving element 9, after the reflected light is converged at the focus position, Light that is guided to the detection side condenser lens 17 of the light receiving element 9 while diffusing, and a pinhole (pinhole) 18 is provided at the focal position, whereby light reflected from other than the focal position of the object side condenser lens 14 can be removed. Noise (for example, the back reflection of the sample).

In this example, the detection-side condenser lens 17 with a focal length of 25 mm is used to pass through a pinhole 18 with an aperture of 20 μm, and the light intensity of reflected light is detected by a light receiving element 9 composed of a photomultiplier tube.

In addition, the stage 2 is equipped with an X table 19x and a Y table 19y movable in the X-axis and Y-axis directions perpendicular to the optical axis Z of the incident light; And the θx platform 20x and the θy platform 20y that tilt in the θy direction, and each platform can be driven by the motors _M5 to _M8 .

In addition, in this example, the polarization axis of the polarizer P is oriented parallel to the X-axis direction, and the slow axis of the 1/2 wavelength plate 12 is oriented in the same direction as the polarization axis at the initial position, while the 1/4 wavelength plate 13 The slow axis of the 1/2 wavelength plate 12 with respect to the slow axis of the offset ± δ (δ ≠ nπ/4, n is an integer) position is set as the initial position, and make the polarization axis of the photodetector A The orientation is parallel to the Y axis.

That is, in the initial state, the polarization axis of the polarizer P and the slow axis of the 1/2 wavelength plate 12 face the X-axis direction, while the slow phase axis of the 1/4 wavelength plate 13 faces +δ or − with respect to the X axis. δ.

Here, after fixing the polarizer P and the photodetector A and rotating the 1/2 wavelength plate 12 by 0 to 180°, the linearly polarized light incident on the 1/4 wavelength plate 13 revolves around the X-axis direction at 0°. The Z axis rotates 0~360°.

At this time, the rotation angle of the linearly polarized light is defined by the rotation angle of its polarization axis. When the rotation angle of the 1/2 wavelength plate 12 is ψ, it passes through the 1/2 wavelength plate 12 and enters the 1/4 wavelength The rotation angle of the polarization axis of the linearly polarized light of the plate 13 is represented by 2ψ.

In addition, since the 1/4 wavelength plate 13 is rotated from the initial position ±δ by a rotation angle twice that of the 1/2 wavelength plate 12, the rotation angle is represented by 2ψ±δ, and the slow axis is relative to the incident linearly polarized light The polarization axis of the α always shifts by ±δ (δ≠nπ/4, n is an integer), so the light passing through the 1/4 wavelength plate 13 is elliptically polarized light.

Thus, the elliptically polarized light is irradiated to the sample while rotating the azimuth angle corresponding to the major axis of the ellipse by 360° while maintaining the ellipticity thereof.

In addition, between the 1/4 wavelength plate 13 and the rotator 16, an observation half-mirror 21 that can advance and retreat on the optical axis is arranged, and a belt for observing the sample 3 is arranged on the reflected optical axis. Camera 22 for lighting.

In addition, the measurement optical system 4 can be housed in a housing (not shown) with a diameter of about 100 mm, whereas the conventional optical system requires a diameter of 600 mm including the operating range, so it can be miniaturized to about 1/36 in terms of area ratio.

The arithmetic processing device 5 is connected with the light receiving element 9, the two-dimensional light position detection element 10 and the camera 22 at its input interface, and is connected with each motor _M1 -M8 at the output interface, and performs the swing of the sample 3 according to the prescribed program. Adjustment, positioning of the measurement point S in the XY plane, measurement of the position in the Z-axis direction of the measurement point S, initial position setting and driving of the 1/2 wavelength plate 12 and 1/4 wavelength plate 13, measurement by the light receiving element 9 Storage of reflected light intensity data, calculation of optical anisotropy parameters, etc.

FIG. 2 is a flowchart showing a series of processing procedures performed by the arithmetic processing unit 5 .

When the sample to be measured for optical anisotropy is placed on the stage 2, and the main switch is turned on, power is supplied to the arithmetic processing device 5, the laser 6, the light receiving element 9, and each motor _M1 ~M8, start to execute the following processing.

First, when the XY coordinates of the measurement point S are input in step STP1, the motors _M5 and _M6 are driven in step STP2 to align the measurement point S with the incident light axis Z through the XY stages 19x and 19y.

[Swing adjustment unit]

Next, in step STP3, the rotator 16 is rotated by the motor _M6 so that the through hole 15 enters and exits the incident optical axis Z. In step STP4, it is judged by the two-dimensional light position detection element 10 whether the optical axis of the reflected light from the sample 3 is consistent with the optical axis Z. The optical axes of the swing detection optical path _L3 are consistent. If they are inconsistent, drive the motors _M7 and _M8 in step STP5 and adjust the swing of the sample 3 through the θx and θy platforms 20x and 20y and return to step STP4. When there is no swing, then Move to step STP6.

[Focus position adjustment unit for the condenser lens on the object side]

In step STP6, the rotator 16 is rotated by the motor _M3 so that the object side condenser lens 14 enters and exits the incident light axis Z, in step STP7 the condenser lens 14 is scanned in the incident light axis Z direction, and in step STP8 the condenser lens 14 is scanned. The position of the optical lens 14 is fixed at the position where the intensity of light received by the light receiving element 9 becomes maximum, and the Z coordinate at this time is stored, and then the process moves to step STP9.

[Measuring point detection unit]

In step STP9, the half-mirror 21 is used for observation in and out of the optical axis Z, and the image analysis of the camera 22 is carried out in step STP10 to judge whether the incident optical axis Z is consistent with the measurement point S, if not consistent, the XY platform 19x is moved in step STP11 , 19y perform fine adjustment and then return to step STP10, store the XYZ coordinates in step STP12 as long as it is irradiated, retract the observation half mirror 21, and move to step STP13.

[Reflected Light Intensity Measuring Unit]

In step _STP13 , the retardation axis of the 1/2 wavelength plate 12 is set to be parallel to the X axis by the motor _M1 , and the retardation axis of the 1/4 wavelength plate 13 is set to face +δ with respect to the X axis by the motor M2 initial position.

Thereafter, in step STP14, the rotation angle of the 1/4 wavelength plate 13 is synchronously driven by the motors M ₁ and M ₂ so that the rotation angle ψ of the 1/2 wavelength plate 12 is doubled, and in step STP15, Then make the 1/2 wavelength plate 12 rotate according to a predetermined angle and measure the reflected light intensity by the light receiving element 9, and the rotation angle of the linearly polarized light passing through the 1/2 wavelength plate 12, that is, the rotation angle of the 1/2 wavelength plate 12 The reflected light intensity R(+δ) is stored corresponding to 2 times the angle.

Then, in step STP16 , the measurement is interrupted at the time point when the 1/2 wavelength plate 12 is rotated by 180°.

Next, in step STP17, the motor _M1 makes the slow axis of the 1/2 wavelength plate 12 parallel to the X axis, and the motor _M2 makes the slow axis of the 1/4 wavelength plate 13 face -δ with respect to the X axis to reset Set the initial position.

Thereafter, in step STP18, the motors M ₁ and M ₂ are synchronously driven such that the rotation angle of the 1/4 wavelength plate 13 becomes twice the rotation angle ψ of the 1/2 wavelength plate 12, and in step STP19, The 1/2 wavelength plate 12 measures the intensity of reflected light through the light receiving element 9 every time the 1/2 wavelength plate 12 is rotated to a predetermined angle, and the rotation angle of the linearly polarized light that has passed through the 1/2 wavelength plate 12 is the 1/2 wavelength plate 12 The reflected light intensity R(-δ) is stored corresponding to twice the angle of rotation.

[Difference Calculation Unit]

Next, it moves to step STP20, and calculates the difference ΔR=R(+δ)−R(−δ) based on the measured reflected light intensities R(+δ) and R(−δ).

In addition, in order to remove light noise caused by the optical system 4, when the sample 3 is set on the stage 2 facing the 0° direction, or when the sample 3 is set on the stage 2 facing the 90° direction, It is also effective to perform the processes of steps STP13 to STP20 when an isotropic material such as glass without optical anisotropy is set on the mounting table 2 .

The individual reflected light intensities R in this case are expressed as follows.

R ₀ (+δ): When the sample 3 is oriented to 0°, and the initial position of the 1/4 wavelength plate 13 is set to +δ,

R ₀ (-δ): when the sample 3 is oriented to 0°, and the initial position of the 1/4 wavelength plate 13 is set to -δ,

R ₉₀ (+δ): When the sample 3 is oriented at 90° and the initial position of the 1/4 wavelength plate 13 is +δ,

R ₉₀ (-δ): When the sample 3 is oriented at 90°, and the initial position of the 1/4 wavelength plate 13 is set to -δ,

R _E (+δ): when an isotropic material is set, and the initial position of the 1/4 wavelength plate 13 is set to +δ,

R _E (-δ): when an isotropic material is provided, and the initial position of the 1/4 wavelength plate 13 is set to -δ,

The difference ΔR can also be calculated by the following formula in addition to the above.

ΔR=[R ₀ (+δ)-R ₀ (-δ)]-[R _E (+δ)-R _E (-δ)]

ΔR=[R ₀ (+δ)-R ₀ (-δ))-[R ₉₀ (+δ)-R ₉₀ (-δ)]

ΔR=ΔR ₀ -ΔR ₉₀

ΔR ₀ =[R ₀ (+δ)-R ₀ (-6)]-[R _E (+δ)-R _E (-δ))

ΔR ₉₀ =[R ₉₀ (+δ)-R ₉₀ (-δ)]-[R _E (+δ)-R _E (-δ)]

[Anisotropy analysis unit]

In step STP21, the difference ΔR of the linearly polarized light with respect to the rotation angle 2ψ is plotted on a graph, and in step STP22 a fitting process is performed to plot a graph of the 2ψ-ΔR graph.

In step STP23 , angles at which ΔR=0 are read, one of which is the direction of the optical axis at the measurement point S of the sample 3 .

In addition, as long as the direction of the optical axis in the measurement point S is the same, it can be said that the anisotropy is large, and it can be evaluated by the amplitude of the height direction of ΔR. Therefore, in step STP24, the magnitude of the anisotropy is evaluated by calculating the difference between the maximum value and the minimum value of ΔR, the height from 0 to the maximum value, etc. reflecting the amplitude in the height direction of ΔR.

The above is a configuration example of the present invention, and the method of the present invention will be described next.

For example, as Sample 3, a TFT substrate for LCD (30 micrometers per pixel) coated with a liquid crystal alignment film subjected to alignment treatment was placed on the mounting table 2 in a direction parallel to the X-axis. The objective lens is rotated by the automatic rotation rotator, and the swing adjustment is performed based on the signal of the optical position detection element while the objective lens is separated from the optical path.

After the wobbling adjustment, the object-side condenser lens 14 is inserted on the incident light axis Z, and the condenser lens 14 is scanned in the Z direction. The Z-direction position of the measurement point S can be measured by fixing the position of the light-collecting lens 14 on the object side at the position where the intensity of the light receiving element 9 becomes maximum and storing the Z coordinate at that time.

Next, the XY stages 19x and 19y are adjusted so that the incident light is irradiated into the pixels of the TFT substrate based on the image of the camera 22, and then the reflected light intensity is measured.

First, set the initial position for the 1/2 wavelength plate 12 so that the retardation axis is parallel to the X axis, and set the retardation axis for the 1/4 wavelength plate 13 at a position where the retardation axis is offset by +δ (+2°) relative to the X axis. initial position.

Then, rotate the 1/2 wavelength plate 12 and the 1/4 wavelength plate 13 at the rotational speeds of 20 rpm and 40 rpm, respectively, in such a manner that the rotation angle of the 1/4 wavelength plate becomes twice that of the 1/2 wavelength plate 12, when 1/2 2 Every time the wavelength plate 12 is rotated by 5° from 0 to 180°, the reflected light intensity R(+δ) is read by the light receiving element 9.

At this time, the light irradiated from the laser 6 travels along the incident optical path L1, the polarization axis of the polarizer P becomes linearly polarized light parallel to the X-axis direction, and the polarization axis of the linearly polarized light is rotated by the 1/2 wavelength plate 12 , converted into elliptically polarized light by the 1/4 wavelength plate 13 configured with a slow phase axis offset of +2°, focused on a light spot with a diameter of 1 micron by the condenser lens 14 on the object side, and irradiated the sample in the vertical direction 3.

Then, the reflected light diffused from the measurement point S of the sample 3 travels along the reflected optical path L2, is parallelized by the condenser lens 14 on the object side, passes through the 1/4 wavelength plate 13 and the 1/2 wavelength plate 12 again, and Converted to linearly polarized light, it is reflected by the half mirror 7, passes through the photodetector A, is reflected by the half mirror 8, and passes through a 20 μm aperture set at the focal point of the detecting side condenser lens 17 The pinhole 18 removes light noise reflected from other than the focal position of the condensing lens 14 on the object side (for example, back reflected light of the sample), and only the reflected light reflected from the measurement point S reaches the light receiving element 9 .

At this time, among the polarized light components included in the reflected light, the polarized light component whose polarization state has not changed passes through the 1/4 wavelength plate 13 again and returns to linearly polarized light, and returns to the linearly polarized light when it passes through the 1/2 wavelength plate 12. It is linearly polarized light whose polarization axis is parallel to the X axis, so it will be cut off by the photodetector A whose polarization axis is parallel to the Y axis. The different polarization states, which thus pass through the photodetector A to the light receiving element 9, can be detected as changes in light intensity.

Next, set the initial position for the 1/2 wavelength plate 12 so that the slow axis is parallel to the X axis, and set the slow axis for the 1/4 wavelength plate 13 at a position where the slow axis is shifted by -δ (-2°) relative to the X axis. After the initial position, similarly, the reflected light intensity R(−δ) is measured by the light receiving element 9 .

Then, the difference ΔR of these reflected light intensities R(+δ) and R(−δ) is calculated by the following formula.

ΔR=R(+δ)-R(-δ)

Fig. 3 (a) to Fig. 3 (c) are graphs representing the measurement results at this time, and the following graphs are the rotation angle 2ψ of the linearly polarized light rotated by the 1/2 wavelength plate 12 on the horizontal axis, and the vertical axis Figure 3(a) is the reflected light intensity R(+δ), Figure 3(b) is the reflected light intensity R(-δ), and Figure 3(c) is the difference △R.

Then, fitting processing is performed on the data in FIG. 3( c ), and the angle 2ψ of the polarization axis that becomes ΔR=0 is read, and it is 10°, 100°, 190°, and 280°.

The alignment treatment direction of the sample 3 placed on the stage 2 is parallel to the X axis (0°), so it can be seen that 10° (190°) closest to 0° is the direction of the optical axis (alignment direction) of the measurement point S.

The magnitude H of the anisotropy can be obtained, for example, by the following formula.

H=ΔRmax-Δrmin

At this time, the size H ₀ of the anisotropy is measured for a good product measured in advance, and based on the ratio H/H ₀ thereto, for example, if it is 0.9 or more, the size of the anisotropy can be judged to be appropriate.

4 is a graph showing the results of measuring the direction of the optical axis at a plurality of measurement points set in a matrix on the surface of the sample 3, and FIG. 5 is a graph showing the distribution state of the anisotropy.

(Example 2)

In addition, since the light noise caused by the measurement optical system 4 is large, in order to remove it, if necessary, the sample 3 is set on the stage 2 facing the 0° direction, and the sample 3 is facing the 90° direction. When it is installed on the stage 2, when an optically isotropic material such as glass without optical anisotropy is installed on the stage 2, measure the reflected light intensity, and calculate the difference as shown below to achieve higher accuracy. Measure optical anisotropy parameters accurately.

FIG. 6 is based on the reflected light intensity R ₀ (+δ) and R ₀ (-δ) from the sample 3 set on the stage 2 with the alignment treatment direction parallel to the X-axis (0° direction), and optical etc. The reflected light intensities R _E (+δ) and R _E (−δ) when glass, which is the tropic material, is placed on the mounting table 2 are used to calculate the measurement results when the difference ΔR is used.

ΔR=[R ₀ (+δ)-R ₀ (-δ))-[R _E (+δ) _-RE (-δ)]

Figure 6(a) is the reflected light intensity R ₀ (+δ), Figure 6(b) is the reflected light intensity R ₀ (-δ), and Figure 6(c) is the difference [R ₀ (+δ)-R ₀ (-δ)], Figure 6(d) is the reflected light intensity _RE (+δ), Figure 6(e) is the reflected light intensity _RE (-δ), Figure 6(f) is its difference [ _RE ( +δ) _－RE (－δ)], Figure 6(g) is the difference △R.

Then, fitting processing was performed on the data in FIG. 6( g ), and the angle 2ψ of the polarization axis at which ΔR=0 was read, and it was 12°, 102°, 192°, and 282°.

Since the alignment treatment direction of the sample 3 placed on the stage 2 is parallel to the X axis (0°), it can be seen that 12° (192°) closest to 0° is the direction of the optical axis of the measurement point S (alignment direction ).

(Example 3)

FIG. 7 is based on the reflected light intensity R ₀ (+δ) and R ₀ (-δ) from the sample 3 set on the stage 2 with the direction of the alignment treatment parallel to the X axis (0° direction). The reflected light intensities R ₉₀ (+δ) and R ₉₀ (-δ) of the sample 3 placed on the stage 2 in the direction of the alignment treatment are oriented parallel to the X-axis (90° direction), and the difference ΔR is calculated by the following formula measurement results.

ΔR=[R ₀ (+δ)-R ₀ (-δ)]-[R ₉₀ (+δ)-R ₉₀ (-δ)]

According to this, the anisotropy inherent in the optical system can be removed, and the size of the anisotropy can be further doubled, so that higher-precision measurement can be performed.

For the reflected light intensities R ₀ (+δ) and R ₀ (−δ), the data of FIG. 6( a ) and FIG. 6( b ) were used.

Figure 7(a) is the reflected light intensity R ₉₀ (+δ), Figure 7(b) is the reflected light intensity R ₉₀ (-δ), and Figure 7(c) shows the difference [R ₉₀ (+δ)-R ₉₀ (-δ)], Fig. 7(d) is the differential ΔR.

Then, fitting processing is performed on the data in FIG. 7( d ), and the angle 2Ψ of the polarization axis that becomes ΔR=0 is read as 15°, 105°, 195°, and 285°.

Since the alignment treatment direction of the sample 3 placed on the stage 2 is parallel to the X axis (0°), it can be seen that 15° (195°) closest to 0° is the direction of the optical axis of the measurement point S (alignment direction ).

(Example 4)

Here, as long as the intermediate data [R ₀ (+δ)-R ₀ (-δ)] and [R ₉₀ (+δ)-R ₉₀ (-δ)] need to be used, and the optical system 4 If the light noise is low, the difference ΔR ₀ and ΔR ₉₀ can be obtained by the following formula.

ΔR ₀ =[R ₀ (+δ)-R ₀ (-δ)]-[R _E (+δ)-R _E (-δ)]

ΔR ₉₀ =[R ₉₀ (+δ)-R ₉₀ (-δ)]-[R _E (+δ)-R _E (-δ)]

Based on these data, the difference ΔR can be obtained by the following formula.

ΔR=ΔR ₀ -ΔR ₉₀ .

Reflected light intensity R ₀ (+δ), R ₀ (-δ), _RE (+δ), _RE (-δ) using Figure 6(a), Figure 6(b), Figure 6(d), Fig. For the data of 6(e), the data of FIG. 7(a) and FIG. 7(b) were used for the reflected light intensities R ₉₀ (+δ) and R ₉₀ (-δ).

Figure 8(a) is the difference ΔR ₀ , and Figure 8(b) is the difference ΔR ₉₀ , the difference ΔR=ΔR ₀ -ΔR ₉₀ is the same as the result in Figure 7(d).

(Example 5)

Fig. 9 is an explanatory view showing another optical anisotropy parameter measuring device of the present invention.

The optical anisotropy parameter measuring device 25 of the present example can evaluate the optical anisotropy for the entire measurement region S ₂ having a certain width (for example, a diameter of 10 mm). In addition, the same code|symbol is attached|subjected to the part which overlaps with FIG. 1, and detailed description is abbreviate|omitted.

In this example, the magnification is set by the beam expander 11 provided between the laser 6 and the half mirror 7 of the measurement optical system 4, so that the incident light has a beam diameter corresponding to the measurement area S2. (eg 10mm diameter) parallel beam.

In addition, the object-side condenser lens 14 , the detection-side condenser lens 17 , and the pinhole 18 in FIG. 1 are not provided.

Accordingly, the incident light that becomes a parallel beam with a diameter of 10 mm in the beam expander 11 passes through the polarizer P, the 1/2 wavelength plate 12, and the 1/4 wavelength plate 13 to become elliptically polarized light, and is irradiated to the measurement of the sample 3. Area S ₂ overall.

The reflected light passes through the 1/4 wavelength plate 13 and the 1/2 wavelength plate 12 in the state of a parallel light beam with a diameter of 10mm, and passes through the photodetector A along the reflected light path _L2 , and reaches the light receiving element 9 to measure its brightness.

At this time, the direction of the optical axis in the measurement area _S2 is detected as the average direction. As long as the direction of the optical axis is consistent, the value H indicating the magnitude of the anisotropy is large. If there is a deviation in the direction of the optical axis, Then, the value H indicating the magnitude of the anisotropy is small.

(Example 6)

FIG. 10 is an explanatory view showing still another optical anisotropy parameter measuring device according to the present invention, and parts overlapping with those in FIG. 1 are assigned the same reference numerals and detailed description thereof will be omitted.

The optical anisotropy parameter measuring device 26 of this example can pass through the entire measurement area S3 even when the diameters of the wave plates 12 and 13 are set to be relatively large (for example, about 1 mm in diameter) in the measurement area _S3 . Evaluation of optical anisotropy was performed with one measurement.

In this example, between the laser 6 and the half mirror 7 of the measurement optical system 4, a beam expander 11 for making the irradiated light a parallel beam with a predetermined beam diameter (for example, 5 mm) is provided, and Between the 1/4 wavelength plate 13 and the stage 2 on which the sample 3 is placed, a beam expander 27 for expanding the diameter of the incident light into a parallel beam having a beam diameter corresponding to the measurement area _S3 is provided.

In addition, the object-side condenser lens 14 , the detection-side condenser lens 17 , and the pinhole 18 in FIG. 1 are not provided.

Accordingly, the incident light that becomes a parallel beam of 5 mm in the initial beam expander 11 passes through the polarizer P, the 1/2 wavelength plate 12, and the 1/4 wavelength plate 13 to become elliptically polarized light, and the beam expander 27 The parallel beam expanded to a diameter of 1 m is irradiated to the entire measurement area _S2 of the sample 3 .

The reflected light becomes a parallel light beam with a diameter of 1 m, travels toward the beam expander 27 in the opposite direction, becomes a parallel light beam with a diameter of 5 mm, passes through the 1/4 wavelength plate 13 and the 1/2 wavelength plate 12, and travels along the reflected light path _L2 . Pass through the photodetector A to reach the light receiving element 9, and measure its light intensity.

At this time, the direction of the optical axis in the measurement area _S2 is detected as the average direction. As long as the direction of the optical axis is consistent, the value H indicating the magnitude of the anisotropy is large, and if there is a deviation, it indicates the degree of anisotropy. The point where the value H of the size is small is the same as in the above-mentioned embodiment.

[industrial availability]

The present invention can be applied to products with optical anisotropy, and is especially suitable for quality inspection of liquid crystal alignment films and the like.

Claims (12)

1. An optical anisotropy parameter measuring device, which measures the direction of the optical axis of the sample and the size of the optical anisotropy based on the change of the polarization state of the incident light and the reflected light irradiated to the measurement area of the sample, The optical anisotropy parameter measuring device is characterized in that it comprises: The measurement optical system irradiates the incident light from the laser as the light source to the measurement area in the vertical direction through the half mirror, and guides the reflected light reflected in the vertical direction from the measurement area to the light receiving area through the half mirror. components; and The arithmetic processing device calculates the optical anisotropy parameter based on the reflected light intensity detected by the light receiving element, In the measurement optical system, a polarizer is arranged between the laser and the half mirror, a photodetector is arranged between the half mirror and the light receiving element, and a detector is arranged between the half mirror and the sample. : a 1/2 wavelength plate which is rotationally driven in order to rotate the linearly polarized light generated by the above-mentioned polarizer; From the initial position of the axis offset ± δ, the rotation angle is synchronously driven in such a way that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, δ≠nπ/4, n is an integer, The above arithmetic processing device calculates the reflected light intensity R(+δ) detected when the 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ, and the 1/4 wavelength plate is rotated from the initial position The difference ΔR of the reflected light intensity R(-δ) detected when the plate is rotated synchronously with the 1/2 wavelength plate from -δ is determined based on the relationship between the rotation angle of the linearly polarized light and the above difference ΔR. The direction of the optical axis and the magnitude of the optical anisotropy. 2. The optical anisotropy parameter measuring device according to claim 1, characterized in that: between the above-mentioned laser and the half mirror of the above-mentioned measurement optical system, a device is set to set the above-mentioned incident light to have a measurement area A beam expander corresponding to the size of the beam diameter of the parallel beam. 3. The optical anisotropy parameter measuring device according to claim 1, characterized in that: Between the above-mentioned laser and the half-mirror of the above-mentioned measurement optical system, a beam expander that sets its irradiation light as a parallel beam with a specified beam diameter is arranged; Between the above-mentioned 1/4 wavelength plate and the above-mentioned sample, an object-side condensing lens is provided so as to be relatively movable in the direction of its optical axis, and the object-side condensing lens condenses the incident light to focus on on the surface of the sample; Between the photodetector and the light receiving element, there is provided a detection side condenser lens that guides the reflected light to the light receiving element while diffusing it after converging on the focal point, and a pinhole is provided at the focal point. 4. The optical anisotropy parameter measuring device according to claim 1, characterized in that: When the above-mentioned measurement area is set to be larger than the diameter of each of the above-mentioned wavelength plates, Between the above-mentioned laser and the half-mirror of the above-mentioned measurement optical system, a beam expander for making the irradiation light a parallel beam with a predetermined beam diameter is provided; A beam expander that expands the diameter of the incident light into a parallel beam having a beam diameter corresponding to a measurement region is provided between the quarter-wavelength plate and the sample. 5. A method for measuring optical anisotropy parameters, measuring the direction of the optical axis of the sample and the size of the optical anisotropy based on the change of the polarization state of the incident light irradiated to the measurement area of the sample and the reflected light thereof, The method for measuring optical anisotropy parameters is characterized by comprising: The measurement optical system irradiates the incident light from the laser as the light source to the measurement area in the vertical direction through the half mirror, and guides the reflected light reflected in the vertical direction from the measurement area to the light receiving area through the half mirror. element, In this measurement optical system, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, a light detector is arranged between the half-mirror and the light-receiving element, and a : a 1/2 wavelength plate which is rotationally driven in order to rotate the linearly polarized light generated by the above-mentioned polarizer; The initial position of the axis offset ±δ is synchronously driven to rotate in such a way that the rotation angle becomes 2 times that of the 1/2 wavelength plate, where δ≠nπ/2, n is an integer, The optical anisotropy parameter measurement method has: In the reflected light intensity measurement step, the reflected light intensity R(+δ) is measured while the 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ, and the 1/4 wavelength plate is rotated from the initial position +δ to From the initial position -δ, it rotates synchronously with the 1/2 wavelength plate while measuring the reflected light intensity R(-δ); The difference calculation step is to calculate the difference ΔR by ΔR=R(+δ)-R(-δ) based on the detected reflected light intensity R(+δ) and R(-δ); In the anisotropy analysis step, the direction of the optical axis and the magnitude of the optical anisotropy are determined based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 6. A method for measuring optical anisotropy parameters, which measures the direction of the optical axis of the sample and the size of the optical anisotropy based on changes in the polarization state of the incident light irradiated to the measurement area of the sample and the reflected light thereof, The method for measuring optical anisotropy parameters is characterized by comprising: The measurement optical system irradiates the incident light from the laser as the light source to the measurement area in the vertical direction through the half mirror, and guides the reflected light reflected in the vertical direction from the measurement area to the light receiving area through the half mirror. element; In this measurement optical system, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, a light detector is arranged between the half-mirror and the light-receiving element, and a : a 1/2 wavelength plate, which is rotationally driven in order to rotate the linearly polarized light generated by the above-mentioned polarizer: and a 1/4 wavelength plate, from which the direction of the retardation axis is relative to that of the retardation of the above-mentioned 1/2 wavelength plate From the initial position of the axis offset ± δ, the rotation angle is synchronously driven in such a way that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, δ≠nπ/4, n is an integer, The optical anisotropy parameter measurement has: In the reflected light intensity measurement step, the above-mentioned sample is set, and the above-mentioned 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ to measure the reflected light intensity R(+δ), so that the above-mentioned 1/4 The wavelength plate rotates synchronously with the 1/2 wavelength plate from the initial position -δ while measuring the reflected light intensity R(-δ); Referring to the reflected light intensity measurement step, instead of the above-mentioned sample, a reference plate without optical anisotropy is provided, and the reference reflected light intensity _RE (+δ) and _RE (-δ) are measured in the same manner as the above-mentioned reflected light intensity measurement step; In the difference calculation step, based on the above-mentioned reflected light intensities R(+δ) and R(-δ), and the above-mentioned reference reflected light intensities _RE (+δ) and _RE (-δ), by ΔR=[R ₀ (+δ)-R ₀ (-δ)]-[R _E (+δ) _-RE (-δ)] to calculate the difference ΔR; and In the anisotropy analysis step, the direction of the optical axis and the magnitude of the optical anisotropy are determined based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 7. A method for measuring optical anisotropy parameters, which measures the direction of the optical axis of the sample and the size of the optical anisotropy based on changes in the polarization state of the incident light irradiated to the measurement area of the sample and the reflected light thereof, The optical anisotropy parameter measuring method is characterized in that comprising: The measurement optical system irradiates the incident light from the laser as the light source to the measurement area in the vertical direction through the half mirror, and guides the reflected light reflected in the vertical direction from the measurement area to the light receiving area through the half mirror. element; In this measurement optical system, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, a light detector is arranged between the half-mirror and the light-receiving element, and a : a 1/2 wavelength plate which is rotationally driven in order to rotate the linearly polarized light generated by the above-mentioned polarizer; From the initial position of the axis offset + δ, it is driven to rotate synchronously in such a way that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, 6≠nπ/4, n is an integer, The optical anisotropy parameter measurement has: In the first reflected light intensity measurement step, the reflected light intensity R is measured while the above-mentioned 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ while the above-mentioned sample is placed in an arbitrary direction. ₀ (+δ), measure the reflected light intensity R ₀ (-δ): In the second reflected light intensity measuring step, the reflected light intensity _R90 (+δ) and R ₉₀ (-δ); The first difference calculation step is based on the reflected light intensity R ₀ (+δ) and R ₀ (-δ) measured in the first reflected light intensity measuring step and the reflection measured in the second reflected light intensity measuring step. Light intensity R ₉₀ (+δ) and R ₉₀ (-δ) through ΔR=[R ₀ (+δ)-R ₀ (-δ))-[R ₉₀ (+δ)-R ₉₀ (-δ)] to calculate the difference ΔR; and In the anisotropy analysis step, the direction of the optical axis and the magnitude of the optical anisotropy are determined based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 8. A method for measuring optical anisotropy parameters, measuring the direction of the optical axis of the sample and the size of the optical anisotropy based on the change of the polarization state of the incident light irradiated to the measurement area of the sample and the reflected light thereof, The method is characterized by comprising: The measurement optical system irradiates the incident light from the laser as the light source to the measurement area in the vertical direction through the half mirror, and guides the reflected light reflected in the vertical direction from the measurement area to the light receiving area through the half mirror. element; In this measurement optical system, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, a light detector is arranged between the half-mirror and the light-receiving element, and a : a 1/2 wavelength plate which is rotationally driven in order to rotate the linearly polarized light generated by the above-mentioned polarizer; From the initial position of the axis offset + δ, it is driven to rotate synchronously in such a way that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, 6≠nπ/4, n is an integer, The optical anisotropy parameter measurement has: In the first reflected light intensity measurement step, the reflected light intensity R is measured while the above-mentioned 1/4 wavelength plate is rotated synchronously with the 1/2 wavelength plate from the initial position +δ while the above-mentioned sample is placed in an arbitrary direction. ₀ (+δ), measure the reflected light intensity R ₀ (-δ): In the second reflected light intensity measuring step, the reflected light intensity _R90 (+δ) and R ₉₀ (-δ); Referring to the reflected light intensity measurement procedure, a reference plate without optical anisotropy is installed instead of the above-mentioned sample, and the reference reflected light intensity _RE (+δ) and _RE (-δ) are measured in the same manner as the first reflected light intensity measurement procedure above. ; The first difference calculation step is based on the reflected light intensities R ₀ (+δ) and R ₀ (−δ) measured in the first reflected light intensity measuring step, and the reference reflected light intensities R ₉₀ (+δ) and R ₉₀ (-δ), through ΔR ₀ =[R ₀ (+δ)-R ₀ (-δ))-[R _E (+δ)-R _E (-δ)] to calculate the difference ΔR ₀ ; The second difference calculation step is based on the reflected light intensities R ₉₀ (+δ) and R ₉₀ (−δ) measured in the second reflected light intensity measuring step, and the reference reflected light intensities R _E (+δ) and R _E (-δ), through ΔR ₉₀ =[R ₉₀ (+δ)-R ₉₀ (-δ)]-[R _E (+δ)-R _E (-δ)] to calculate the difference ΔR ₉₀ ; In the third difference calculation step, based on the above-mentioned differences ΔR ₀ and ΔR ₉₀ , by ΔR=ΔR ₀ -ΔR ₉₀ to calculate the difference ΔR; and In the anisotropy analysis step, the direction of the optical axis and the magnitude of the optical anisotropy are determined based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 9. A program for measuring optical anisotropy parameters, which uses a computer to operate the measuring optical system, and measures the direction of the optical axis of the sample and the size of the optical anisotropy based on the intensity of the reflected light detected by the light receiving element, This measurement optical system is formed with an optical path in which incident light is irradiated from a laser as a light source to the measurement area of the sample in a vertical direction through a half mirror and reflected light is reflected in a vertical direction from the measurement area. Guided to the above-mentioned light-receiving element via the above-mentioned half-mirror, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, and a photodetector is arranged between the half-mirror and the light-receiving element, Arranged between the mirror and the sample are: a 1/2 wavelength plate that is rotationally driven to rotate the linearly polarized light generated by the above-mentioned polarizer; and a 1/4 wavelength plate that makes the direction of the slow axis relative From the initial position of the retardation axis offset +δ of the above-mentioned 1/2 wavelength plate, it is rotationally driven synchronously in such a manner that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, 6≠nπ/4, n is an integer, The program for measuring optical anisotropy parameters has: The reflected light intensity measurement unit sets the above-mentioned 1/4 wavelength plate at the initial position +δ, and measures the reflected light intensity R(+δ) with the above-mentioned light receiving element while rotating and driving it synchronously with the 1/2 wavelength plate, And it is stored in a preset storage area in association with the rotation angle of the above-mentioned linearly polarized light, and the above-mentioned 1/4 wavelength plate is set at the initial position -δ, and one side is rotated and driven synchronously with the 1/2 wavelength plate. Use the light-receiving element to measure the reflected light intensity R(-δ), and store it in a preset storage area in association with the rotation angle of the above-mentioned linearly polarized light; The difference calculation unit, based on the stored reflected light intensity R(+δ) and R(-δ), through ΔR=R(+δ)-R(-δ) to calculate the difference ΔR; and The anisotropy analysis unit determines the direction of the optical axis and the magnitude of the optical anisotropy based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 10. A program for measuring optical anisotropy parameters, operating the measuring optical system through a computer, and measuring the direction of the optical axis of the sample and the size of the optical anisotropy based on the intensity of reflected light detected by the light receiving element, This measurement optical system is formed with an optical path in which incident light is irradiated from a laser as a light source to the measurement area of the sample in a vertical direction through a half mirror and reflected light is reflected in a vertical direction from the measurement area. Guided to the above-mentioned light-receiving element via the above-mentioned half-mirror, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, and a photodetector is arranged between the half-mirror and the light-receiving element, Arranged between the mirror and the sample are: a 1/2 wavelength plate that is rotationally driven to rotate the linearly polarized light generated by the above-mentioned polarizer; and a 1/4 wavelength plate that makes the direction of the slow axis relative From the initial position where the retardation axis of the above-mentioned 1/2 wavelength plate is shifted by ±δ, it is rotationally driven synchronously so that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, 6≠nπ/4, n is an integer, The program for measuring optical anisotropy parameters has: The reflected light intensity measurement unit sets the above-mentioned 1/4 wavelength plate at the initial position +δ, and measures the reflected light intensity R(+δ) with the above-mentioned light receiving element while rotating and driving it synchronously with the 1/2 wavelength plate, And it is stored in a preset storage area in association with the rotation angle of the above-mentioned linearly polarized light, and the above-mentioned 1/4 wavelength plate is set at the initial position -δ, and one side is rotated and driven synchronously with the 1/2 wavelength plate. Use the light-receiving element to measure the reflected light intensity R(-δ), and store it in a preset storage area in association with the rotation angle of the above-mentioned linearly polarized light; Referring to the reflected light intensity measuring unit, for a reference plate without optical anisotropy, measure the reference reflected light intensity _RE (+δ) and _RE (-δ) in the same way as the above-mentioned reflected light intensity measuring unit; The difference calculation unit is based on the above-mentioned reflected light intensities R(+δ) and R(-δ) and the above-mentioned reference reflected light intensities R _E (+δ) and R _E (-δ), by ΔR=[R ₀ (+δ)-R ₀ (-δ)]-[R _E (+δ)-R _E (-δ)] to calculate the difference ΔR; and The anisotropy analysis unit determines the direction of the optical axis and the magnitude of the optical anisotropy based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 11. A program for measuring optical anisotropy parameters, operating the measuring optical system through a computer, and measuring the direction of the optical axis of the sample and the size of the optical anisotropy based on the intensity of reflected light detected by the light receiving element, This measurement optical system is formed with an optical path in which incident light is irradiated to the measurement area of the sample in a vertical direction from a laser as a light source via a half mirror, and reflected light is reflected in a vertical direction from the measurement area. Guided to the above-mentioned light-receiving element via the above-mentioned half-mirror, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, and a photodetector is arranged between the half-mirror and the light-receiving element, Arranged between the mirror and the sample are: a 1/2 wavelength plate that is rotationally driven to rotate the linearly polarized light generated by the polarizer; and a 1/4 wavelength plate that makes the direction of the slow axis relative to the The retardation axis of the above-mentioned 1/2 wavelength plate deviates from the initial position of the snake, and is rotationally driven synchronously so that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, δ≠nπ/4, n is integer, The program for measuring optical anisotropy parameters has: The first reflected light intensity measurement unit measures the reflected light intensity R ₀ (+ δ), measure the reflected light intensity R ₀ (-δ) while rotating the above-mentioned 1/4 wavelength plate synchronously with the 1/2 wavelength plate from the initial position -δ, and compare each reflected light intensity with the rotation of the linearly polarized light Angles are associated and stored in a preset storage area; The second reflected light intensity measuring unit measures the reflected light intensity _R90 (+δ) and R ₉₀ (-δ), and correlate each reflected light intensity with the rotation angle of the above-mentioned linearly polarized light and store it in a preset storage area; The difference calculation step is based on the reflected light intensity R ₀ (+δ) and R ₀ (-δ) measured in the first reflected light intensity measuring unit and the reflected light intensity measured in the second reflected light intensity measuring unit R ₉₀ (+δ) and R ₉₀ (-δ), through ΔR=[R ₀ (+δ)-R ₀ (-δ)]-[R ₉₀ (+δ)-R ₉₀ (-δ)] to calculate the difference ΔR; and The anisotropy analysis unit determines the direction of the optical axis and the magnitude of the optical anisotropy based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR. 12. A program for measuring optical anisotropy parameters, operating the measuring optical system through a computer, and measuring the direction of the optical axis of the sample and the size of the optical anisotropy based on the intensity of reflected light detected by the light receiving element, This measurement optical system is formed with an optical path in which incident light is irradiated from a laser as a light source to the measurement area of the sample in a vertical direction through a half mirror and reflected light is reflected in a vertical direction from the measurement area. Guided to the above-mentioned light-receiving element via the above-mentioned half-mirror, a polarizer is arranged between the above-mentioned laser and the above-mentioned half-mirror, and a photodetector is arranged between the half-mirror and the light-receiving element, Arranged between the mirror and the sample are: a 1/2 wavelength plate that is rotationally driven to rotate the linearly polarized light generated by the above-mentioned polarizer; and a 1/4 wavelength plate that makes the direction of the slow axis relative The retardation axis of the above-mentioned 1/2 wavelength plate deviates from the initial position of the snake, and is rotationally driven synchronously so that the rotation angle becomes 2 times that of the 1/2 wavelength plate, wherein, δ≠nπ/4, n is integer, The program for measuring optical anisotropy parameters has: The first reflected light intensity measurement unit measures the reflected light intensity R ₀ (+δ) while rotating the 1/4 wavelength plate synchronously with the 1/2 wavelength plate from the initial position +δ for the sample placed in any direction. ), measure the reflected light intensity R ₀ (-δ) while making the above 1/4 wavelength plate rotate synchronously with the 1/2 wavelength plate from the initial position -δ, and make each reflected light intensity and the rotation angle of the linearly polarized light Associated and stored in a preset storage area; The second reflected light intensity measuring unit measures the reflected light intensity _R90 (+δ) and R ₉₀ (-δ), and correlate each reflected light intensity with the rotation angle of the above-mentioned linearly polarized light and store it in a preset storage area; The second reflected light intensity measuring unit measures the reference reflected light intensity R _E (+δ) and R _E in the same manner as the above first reflected light intensity measuring unit with respect to a reference plate without optical anisotropy provided instead of the above sample. (-δ), and correlate each reflected light intensity with the rotation angle of the above-mentioned linearly polarized light and store it in a preset storage area; The first difference calculation step is based on the reflected light intensities R ₀ (+δ) and R ₀ (-δ) measured by the first reflected light intensity measuring unit, and the reference reflected light intensities R _E (+δ) and R _E (-δ), through ΔR ₀ =[R ₀ (+δ)-R ₀ (-δ)]-[R _E (+δ)-R _E (-δ)] to calculate the difference ΔR ₀ ; The second difference calculation step is based on the reflected light intensities R ₉₀ (+δ) and R ₉₀ (-δ) measured by the second reflected light intensity measuring unit, and the reference reflected light intensities R _E (+δ) and R _E (-δ), through ΔR ₉₀ =[R ₉₀ (+δ)-R ₉₀ (-δ)]-[R _E (+δ)-R _E (-δ)] to calculate the difference ΔR ₉₀ ; The third difference calculation unit, based on the above-mentioned differences ΔR ₀ and ΔR ₉₀ , by ΔR=ΔR ₀ -ΔR ₉₀ to calculate the difference ΔR; and The anisotropy analysis unit determines the direction of the optical axis and the magnitude of the optical anisotropy based on the relationship between the rotation angle of the linearly polarized light and the difference ΔR.

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