JP2013109220A - Method for evaluating phase difference film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaluation method capable of easily evaluating the linearity of a region of a phase difference film having a pattern and accuracy of pitches.SOLUTION: In an evaluation system comprising a light source, a reference member, a phase difference film, a detachable polarizing filter and a photodetector in this order, the reference member has a polarizer and a light-transmitting region extending in one reference direction, the phase difference film comprises a first phase difference film having uniform phase difference in a plane and a second phase difference film alternately having a plurality of anisotropic regions and isotropic regions extending in one direction in a plane. A plurality of spots in the reference direction of the reference member are observed without mounting a polarizing filter to set a reference line parallel to the reference direction at the plurality of spots in the same manner and the plurality of spots are observed by mounting a polarizing filter to measure the deviation between the reference line and an edge of a part in which light is detected, thereby evaluating the linearity of the anisotropic regions and isotropic regions from the difference in deviation.

Description

  The present invention relates to an evaluation method for evaluating a retardation film.

  As an aspect of the stereoscopic image display device, a device including a retardation film having a specific pattern provided in a state of being aligned with a pixel is known. For example, in a passive-type stereoscopic image display device, a right-eye image and a left-eye image are usually displayed simultaneously on the same screen, and these images are distributed to the left and right eyes using dedicated glasses. ing. Therefore, the passive stereoscopic image display device is required to display the right-eye image and the left-eye image in different polarization states. In order to achieve such display, a passive stereoscopic image display device may be provided with a retardation film having a pattern composed of a plurality of types of regions having two or more types of different retardations (retardation). . Moreover, the retardation film which has the pattern which consists of a multiple types of area | region which has a slow axis in two or more different directions may be provided (refer patent documents 1-5).

  The retardation film having the above-described pattern is usually used by being bonded to a liquid crystal panel in a stereoscopic image display device including a liquid crystal display device. At this time, the position of the retardation film is adjusted according to the arrangement of the pixel region of the liquid crystal panel. Specifically, it is required to adjust the position so that the pixel region of the liquid crystal panel and the region constituting the pattern in the retardation film overlap each other precisely.

JP 2008-170557 A Japanese Patent No. 3461680 Japanese Patent No. 3342454 JP 2005-49865 A Japanese Patent No. 4553769

Generally, in a retardation film having a pattern, a region constituting the pattern is formed so as to extend in one direction. Thus, the property that the region constituting the pattern extends straight in one desired direction is called linearity. However, conventionally, the direction in which the region constituting the pattern extends deviates from a desired direction, or the region meanders and does not extend in one direction, and the linearity may be impaired.
In addition, for example, the pitch of the area constituting the pattern of the retardation film may not be a desired size.

  Thus, when the linearity is impaired or the desired pitch is not obtained, and the accuracy of the area constituting the pattern is not sufficient, the pixel area of the liquid crystal panel and the area constituting the phase difference film pattern Cannot be aligned with high accuracy. For this reason, when a retardation film having low linearity or pitch accuracy is used, there is a film in which a light shielding layer is provided on the retardation film (for example, JP-A No. 2002-185983). However, such a light shielding layer lowers the brightness of the screen.

  Therefore, in a retardation film having a pattern, development of a technique capable of improving the linearity of a region constituting the pattern and controlling the pitch of the region constituting the pattern with high accuracy is being advanced. However, conventionally, in order to evaluate the formed pattern, visual evaluation with an optical microscope must be performed (for example, JP 2011-128589 A, JP 2011-145668 A), and the pattern is configured. There was no easy way to evaluate the linearity and pitch accuracy of the region. For this reason, much time and effort are required to evaluate how much the linearity of the region and the accuracy of the pitch of the region can be improved by the developed technology, which hinders development.

  The present invention has been made in view of the above problems, and an object thereof is to provide an evaluation method that can easily evaluate the linearity or pitch accuracy of a region of a retardation film having a pattern.

As a result of intensive studies to solve the above-mentioned problems, the present inventors combined a reference member having a light-transmitting region and a light-shielding region as a reference, and observing a retardation film using polarized light, By measuring the amount of deviation from the reference of the region constituting the pattern in the retardation film, it was found that the linearity and pitch accuracy of the region of the retardation film can be evaluated from this amount of deviation, and the present invention was completed. I let you.
That is, the present invention is as follows.

[1] An evaluation method for evaluating the retardation film in an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order,
The reference member includes a polarizer and has a light-transmitting region extending in one reference direction,
The retardation film includes a first retardation film having a uniform retardation in a plane in an effective region of the retardation film, and a plurality of anisotropic regions and isotropic regions extending in one direction. A second retardation film having alternating in
By illuminating the light source, observing a plurality of points in the reference direction of the translucent region of the reference member with the photodetector without attaching the polarizing filter, a reference line parallel to the reference direction is obtained. The same setting at the plurality of points, and the amount of deviation between the reference line and the edge of the portion where the light emitted from the light source is detected by attaching the polarizing filter and observing with the photodetector Measuring and
An evaluation method for evaluating linearity of the anisotropic region and the isotropic region of the second retardation film from a difference between the plurality of points in the reference direction of the deviation amount.
[2] The reference member is a liquid crystal panel,
The light-transmitting region of the reference member is a pixel region of the liquid crystal panel;
[1] The evaluation method according to [1], wherein observation with the photodetector is performed in a state where a lattice having a line parallel to the reference direction and a line perpendicular to the reference direction is displayed on the liquid crystal panel.
[3] The reference member includes a substrate capable of transmitting light emitted from the light source, and a plurality of black stripes formed on the substrate and extending in parallel with the reference direction,
The evaluation method according to [1], wherein the light-transmitting region of the reference member is provided between the black stripes.
[4] The evaluation method according to any one of [1] to [3], wherein the polarizing filter is a circular polarizing filter.
[5] The evaluation method according to any one of [1] to [4], wherein the retardation of the first retardation film is a quarter wavelength.
[6] The evaluation method according to any one of [1] to [5], in which a retardation of the anisotropic region of the second retardation film is ½ wavelength.
[7] In an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order, an evaluation method for evaluating the retardation film,
The reference member includes a polarizer and has a light-transmitting region extending in one reference direction,
The retardation film has a plurality of anisotropic regions extending in one direction and having different slow axis directions alternately in a plane,
By illuminating the light source, observing a plurality of points in the reference direction of the translucent region of the reference member with the photodetector without attaching the polarizing filter, a reference line parallel to the reference direction is obtained. The same setting at the plurality of points, and the amount of deviation between the reference line and the edge of the portion where the light emitted from the light source is detected by attaching the polarizing filter and observing with the photodetector Measuring and
The evaluation method which evaluates the linearity of the said anisotropic area | region of the said retardation film from the difference between these points in the said reference direction of the said deviation | shift amount.
[8] The reference member is a liquid crystal panel,
The light-transmitting region of the reference member is a pixel region of the liquid crystal panel;
[7] The evaluation method according to [7], wherein observation with the photodetector is performed in a state where a lattice having a line parallel to the reference direction and a line perpendicular to the reference direction is displayed on the liquid crystal panel.
[9] The reference member includes a substrate capable of transmitting light emitted from the light source, and a black stripe formed on the substrate and extending in parallel with the reference direction,
The evaluation method according to [7], wherein the light-transmitting region of the reference member is provided between the black stripes.
[10] The evaluation method according to any one of [7] to [9], wherein the polarizing filter is a circular polarizing filter.
[11] The evaluation method according to any one of [7] to [10], wherein the retardation of the anisotropic region of the retardation film is a quarter wavelength.
[12] An evaluation method for evaluating the retardation film in an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order,
The reference member includes a polarizer and has a plurality of light transmitting regions extending in one reference direction,
The retardation film includes a first retardation film having a uniform retardation in a plane in an effective region of the retardation film, and a plurality of anisotropic regions and isotropic regions extending in one direction. A second retardation film having alternating in
By illuminating the light source, a plurality of points in the direction perpendicular to the reference direction of the light-transmitting region of the reference member are observed with the photodetector without attaching the polarizing filter, and are parallel to the reference direction. The same reference line at the plurality of points, and the edge of the portion where the reference line and the light emitted from the light source are detected by attaching the polarizing filter and observing with the photodetector Measuring the amount of deviation from
An evaluation method for evaluating the pitch accuracy of the anisotropic region and the isotropic region of the second retardation film from the difference between the plurality of points in a direction perpendicular to the reference direction of the deviation amount.
[13] An evaluation method for evaluating the retardation film in an evaluation system including a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order,
The reference member includes a polarizer and has a plurality of light transmitting regions extending in one reference direction,
The retardation film has a plurality of anisotropic regions extending in one direction and having different slow axis directions alternately in a plane,
By illuminating the light source, a plurality of points in the direction perpendicular to the reference direction of the light-transmitting region of the reference member are observed with the photodetector without attaching the polarizing filter, and are parallel to the reference direction. The same reference line at the plurality of points, and the edge of the portion where the reference line and the light emitted from the light source are detected by attaching the polarizing filter and observing with the photodetector Measuring the amount of deviation from
The evaluation method of evaluating the accuracy of the pitch of the anisotropic region of the retardation film from the difference between the plurality of points in a direction perpendicular to the reference direction of the deviation amount.

  According to the evaluation method for evaluating the retardation film of the present invention, the linearity or pitch accuracy of the region of the retardation film having a pattern can be easily evaluated.

FIG. 1 is a top view schematically showing an example of a pattern that the second retardation film may have. FIG. 2 is a top view schematically showing an example of the relative positional relationship between the anisotropic region and the isotropic region of the second retardation film and the pixels of the liquid crystal panel. FIG. 3 is an exploded perspective view schematically showing an evaluation system according to the first embodiment of the present invention. FIG. 4 is a plan view schematically showing an image displayed on the liquid crystal panel in the first embodiment of the present invention. FIG. 5 shows in the field of view of the microscope when an intersection of a line parallel to the reference direction and a line perpendicular to the reference direction X is observed without attaching a circular polarizing filter in the first embodiment of the present invention. It is a figure which shows an image typically. FIG. 6 shows a microscope field of view when an intersection between a line parallel to the reference direction X and a line perpendicular to the reference direction X is observed in the first embodiment of the present invention. It is a figure which shows an image typically. FIG. 7 is a plan view schematically showing an image displayed on the liquid crystal panel in the first embodiment of the present invention. FIG. 8 schematically shows a plurality of intersections where one line parallel to the reference direction X intersects with a plurality of lines perpendicular to the reference direction X, which is observed when the circular polarizing filter is attached. FIG. FIG. 9 is a plan view schematically showing an image displayed on the liquid crystal panel in the first embodiment of the present invention. FIG. 10 schematically shows a plurality of intersections where one line perpendicular to the reference direction X intersects with a plurality of lines parallel to the reference direction X, which is observed when the circular polarizing filter is attached. FIG. FIG. 11 is an exploded perspective view schematically showing an evaluation system according to the second embodiment of the present invention. FIG. 12 is a plan view schematically showing a state in which the multilayer black stripe film is viewed from the microscope side in the second embodiment of the present invention. FIG. 13 is a diagram schematically showing an image appearing in the field of view of the microscope when a certain point of the multilayer black stripe film is observed without attaching the circular polarizing filter in the second embodiment of the present invention. . FIG. 14 is a diagram schematically showing an image appearing in the field of view of the microscope when the circular polarizing filter is attached and the point of the multilayer black stripe film is observed in the second embodiment of the present invention. FIG. 15 is an exploded perspective view schematically showing an evaluation system according to the third embodiment of the present invention. FIG. 16 is an exploded perspective view schematically showing an evaluation system according to the fourth embodiment of the present invention. FIG. 17 is a plan view schematically showing an image displayed on the liquid crystal panel in the first embodiment. FIG. 18 is a diagram showing the results of Example 1. FIG. 19 is a diagram showing the results of Example 3. FIG. 20 is a diagram showing the results of Example 5.

  Hereinafter, the present invention will be described in detail with reference to embodiments, examples, etc., but the present invention is not limited to the embodiments, examples, etc. described below. You may implement it changing arbitrarily in the range which does not deviate from an equivalent range.

In the following description, “long” means one having a length of at least 5 times the width, preferably 10 times or more, specifically a roll shape. It has a length enough to be wound up and stored or transported.
The “1/2 wavelength plate”, “¼ wavelength plate”, “polarizing plate”, and “substrate” are not only rigid members but also flexible members such as resin films, for example. Including.

  Further, “phase difference” means in-plane retardation (in-plane retardation) unless otherwise specified. The in-plane retardation of the film is a direction perpendicular to the thickness direction of the film (in-plane direction) and has a refractive index nx in the direction giving the maximum refractive index, and is in the in-plane direction and perpendicular to the nx direction. The refractive index ny and the film thickness d of the film are values represented by (nx−ny) × d. The in-plane retardation can be measured using a commercially available retardation measuring device (for example, “KOBRA-21ADH” manufactured by Oji Scientific Instruments, “WPA-micro” manufactured by Photonic Lattice) or the Senalmon method.

Further, “(meth) acrylate” means “acrylate” and “methacrylate”, and “(meth) acryl” means “acryl” and “methacryl”.
“Ultraviolet light” means light having a wavelength of 1 nm or more and 400 nm or less.

Further, the directions of the constituent elements “parallel”, “vertical”, and “orthogonal” include errors within a range that does not impair the effect of the present invention, for example, ± 5 °, unless otherwise specified. Also good. Further, “along” in a certain direction means “in parallel” in a certain direction unless otherwise specified.
In the following description, the angle of the optical axis of the optical element, such as the transmission axis of the polarizing plate and the slow axis of the retardation film, means an angle viewed from the thickness direction unless otherwise specified. .

[1. First embodiment]
[1.1. (Target of evaluation)
The retardation film to be evaluated in the first embodiment of the present invention is a film having a multilayer structure including a first retardation film and a second retardation film. Moreover, the retardation film may be provided with other layers, such as an adhesive layer, in addition to the first retardation film and the second retardation film.

(First retardation film)
The first retardation film has a uniform retardation in the plane in the effective area of the retardation film.
Here, the effective area means an area where light for displaying an image can pass through the retardation film when the retardation film is provided in the stereoscopic image display device. In general, the screen of the stereoscopic image display device is surrounded by a frame, and an area obtained by projecting the screen surrounded by the frame onto the retardation film in the thickness direction is usually an effective area of the retardation film. In this case, an alignment mark or the like for alignment with the liquid crystal panel may be provided on the outer periphery other than the effective area.

  Also, having a uniform retardation in the plane means that the first retardation film does not have a pattern composed of an anisotropic region and an isotropic region, unlike the second retardation film. Specifically, if the in-plane retardation variation of the first retardation film is preferably within ± 20 nm, more preferably within ± 10 nm, the retardation is uniform.

  Further, the first retardation film usually has a uniform slow axis direction in the plane in the effective area of the retardation film. Here, that the slow axis direction is uniform in the plane means that the variation in the slow axis direction in the plane of the second retardation film is preferably within ± 5 °, more preferably within ± 1 °. That means.

  The specific retardation of the first retardation film may be set according to the configuration of the stereoscopic image display device to which the retardation film is applied. For example, the retardation of the first retardation film may be set to a quarter wavelength, and the first retardation film may function as a quarter wavelength plate. A phase difference of ¼ wavelength means that the phase difference is usually within a range of ± 65 nm, preferably ± 30 nm, more preferably ± 10 nm from a value that is ¼ of the center value of the wavelength range of transmitted light. Alternatively, it indicates that the value is within the range of ± 65 nm, preferably ± 30 nm, more preferably ± 10 nm from the value of 3/4 of the central value. Since the transmitted light is usually visible light, the center value of the wavelength range of the transmitted light is usually 550 nm, which is the center value of the wavelength range of the transmitted light.

  When the first retardation film is a rectangular film, the angle formed by the longitudinal direction of the first retardation film and the slow axis direction of the first retardation film is set according to the mode of the stereoscopic image display device. May be. For example, the slow axis direction of the first retardation film may be a direction parallel to or perpendicular to the longitudinal direction. Further, for example, by using a stretched film obliquely stretched as the first retardation film, the slow axis direction of the first retardation film is about 45 ° with respect to the longitudinal direction (for example, 45 ° ± 5 °, preferably 45 °). It is good also as a direction which makes the angle of (degree +/- 1 degree).

(Second retardation film)
The second retardation film has an anisotropic region and an isotropic region at different positions in the plane.
Here, the anisotropic region means a region having an in-plane refractive index having anisotropy. The anisotropic region has an in-plane retardation due to an in-plane refractive index having anisotropy. The specific magnitude of the in-plane retardation of the anisotropic region may be, for example, ½ wavelength. Thereby, the anisotropic region can function as a half-wave plate. Here, the phase difference is ½ wavelength means that the in-plane retardation value measured at a measurement wavelength of 550 nm is usually 225 nm or more, preferably 245 nm or more, and usually 285 nm or less, preferably 265 nm or less. Say.

  The isotropic region refers to a region where the in-plane refractive index is isotropic. The isotropic region has no or no phase difference due to the in-plane refractive index being isotropic, so that the phase difference is small. The specific magnitude of the phase difference in the isotropic region is preferably approximately zero. Specifically, the in-plane retardation value measured at a measurement wavelength of 550 nm is usually 20 nm or less, preferably 10 nm or less, and more preferably 5 nm or less. The lower limit is ideally 0 nm, but is usually 1 nm or more.

  The second retardation film has a plurality of the anisotropic regions and the isotropic regions, respectively. These anisotropic regions and isotropic regions are formed extending in one direction. Moreover, the anisotropic region and the isotropic region are alternately arranged in the direction intersecting the extending direction, and constitute a pattern according to the use of the retardation film as a whole. Usually, since the retardation film is used in combination with the liquid crystal panel of the liquid crystal display device, the specific pattern of the anisotropic region and the isotropic region of the second retardation film according to the arrangement of the pixels of the liquid crystal panel. Is set.

  When the liquid crystal display device is a passive stereoscopic image display device, the liquid crystal panel usually has two sets of pixel groups, that is, a pixel group that displays a right-eye image and a pixel group that displays a left-eye image. In this case, in the pattern of the anisotropic region and the isotropic region of the second retardation film, the region corresponding to one of these pixel groups is an isotropic region, and the region corresponding to the other is anisotropic. It is good also as a pattern which is a sex region.

FIG. 1 is a top view schematically showing an example of a pattern that the second retardation film may have. In FIG. 1, the anisotropic region is indicated by hatching.
As shown in FIG. 1, in the second retardation film 10, the anisotropic region 11 and the isotropic region 12 usually have a strip shape extending in one direction X. Further, the second retardation film 10 has an in-plane anisotropic region 11 and isotropic region 12 in a direction Y perpendicular to the direction X in which the anisotropic region 11 and the isotropic region 12 extend. Have alternately. Therefore, the second retardation film 10 has a stripe pattern composed of these anisotropic regions 11 and isotropic regions 12. The second retardation film 10 has a boundary line 13 between the anisotropic region 11 and the isotropic region 12 as a line extending in one direction.

Width W ₁₂ of width W ₁₁ and the isotropic region 12 of the anisotropic region 11 is usually set in accordance with the dimensions of the pixels of the liquid crystal panel combined with a retardation film. In general, the size of the pixels of the liquid crystal panel is uniform, the width W ₁₂ of width W ₁₁ and the isotropic region 12 of the anisotropic region 11 is often set to the same extent.
Further, the boundary line 13 between the anisotropic region 11 and the isotropic region 12 is usually aligned at a position corresponding to a black matrix between pixels of the liquid crystal panel. The black matrix is usually formed at a position corresponding to a pixel between the pixels of the liquid crystal panel in a color filter provided in the liquid crystal panel. The black matrix is made of a material that can block visible light, and has a certain width. Therefore, minute width of the black matrix, since there may be a difference between the width W ₁₂ of width W ₁₁ and the isotropic region 12 of the anisotropic region 11, the width W ₁₁ of the anisotropic areas 11 width W of the isotropic region 12 ₁₂ may be not necessarily the same.

FIG. 2 is a top view schematically showing an example of the relative positional relationship between the anisotropic region 11 and the isotropic region 12 of the second retardation film 10 and the pixels of the liquid crystal panel. In the example of FIG. 2, the liquid crystal panel 20 is a liquid crystal panel for a passive stereoscopic image display device, and includes two groups of pixels, that is, a pixel group that displays a right-eye image and a pixel group that displays a left-eye image. Have. The pixel R ₁ , the pixel G _1, and the pixel B ₁ constitute a first pixel group of the two sets of pixel groups, and the pixel R ₂ , the pixel G _2, and the pixel B ₂ constitute a second pixel group. Yes. The pixels of each pixel group are aligned in the longitudinal direction of the liquid crystal panel 20 (the coordinate axis X direction in the figure), and constitute a pixel region 21 composed of a first pixel group and a pixel region 22 composed of a second pixel group. .

  The pixel regions 21 and 22 are alternately arranged in the width direction (the coordinate axis Y direction) of the liquid crystal panel 20. Therefore, the first pixel group and the second pixel group are separated by the black matrix 23 extending in the longitudinal direction (coordinate axis X direction) of the liquid crystal panel 20. In this example, the retardation film is aligned so that the boundary line 13 between the anisotropic region 11 and the isotropic region 12 of the second retardation film 10 of the retardation film is located on the black matrix 23. The

  When performing such alignment, if the linearity of the anisotropic region 11 or the isotropic region 12 of the second retardation film 10 is impaired or the pitch accuracy is reduced, the anisotropic region 11 and the like The boundary line 13 with the anisotropic region 12 cannot be positioned on the black matrix 23, and a desired stereoscopic image display device may not be manufactured. For example, if the boundary line 13 is not positioned on the black matrix 23, crosstalk occurs, which may cause a defective product. Here, crosstalk means a phenomenon in which a left-eye image is visually recognized by the right eye and a right-eye image is visually recognized by the left eye in the stereoscopic image display device.

  Thus, the linearity and pitch of the anisotropic region 11 and the isotropic region 12 of the second retardation film 10 included in the retardation film are evaluated, and the retardation film can be appropriately aligned. If the selection is made, whether or not the stereoscopic image display device is defective can be suppressed. At this time, if the evaluation method according to the first embodiment of the present invention is used, the retardation film can be easily evaluated.

  The thickness of the second retardation film can be set to an appropriate thickness so that a desired retardation is obtained in each of the anisotropic region and the isotropic region. Usually, the thickness of the second retardation film is in the range of 0.5 μm to 50 μm.

(Any layer)
In addition to the first retardation film and the second retardation film, the retardation film may include an arbitrary layer as long as the effects of the present invention are not significantly impaired. For example, you may provide the contact bonding layer which bonds a 1st phase difference film and a 2nd phase difference film. An adhesive layer is a layer formed of an adhesive. This adhesive is not only a narrowly-defined adhesive (an adhesive having a shear storage modulus of 1 to 500 MPa at 23 ° C. after irradiation with energy rays or after heat treatment), but also has a shear storage modulus of less than 1 MPa at 23 ° C. The adhesive which is is also included.

[1.2. Evaluation system)
FIG. 3 is an exploded perspective view schematically showing an evaluation system according to the first embodiment of the present invention. In FIG. 3, the pixel region for the left eye of the liquid crystal cell and the anisotropic region of the second retardation film are indicated by hatching.

  As shown in FIG. 3, the evaluation system 100 according to the first embodiment of the present invention includes a light source 110, a liquid crystal panel 120 as a reference member, a retardation film 130, and a circularly polarizing filter as a detachable polarizing filter. 140 and a microscope 150 as a photodetector are provided in this order. In such an evaluation system 100, for example, a retardation film 130 to be evaluated is attached to an evaluation apparatus including a light source 110, a liquid crystal panel 120, a detachable circular polarizing filter 140, and a microscope 150 in this order. Can be configured.

Here, the liquid crystal panel 120, the retardation film 130, and the circularly polarizing filter 140 are all arranged such that their principal surfaces are parallel to the horizontal direction and the thickness directions thereof coincide. Therefore, in the following description, unless otherwise specified, “thickness direction” means the thickness direction described above.
Moreover, in FIG. 3, although each element which comprises the evaluation system 100 was shown apart from each other for illustration, some or all of them may be in contact with each other in an actual aspect.

(Light source 110)
The light source 110 is a device that can emit non-polarized light for evaluation. Usually, a device capable of emitting visible light is used as the light source 110.

(LCD panel 120)
The liquid crystal panel 120 includes a polarizing film 121 that is a polarizer, a liquid crystal cell 122, and a polarizing film 123 that is a polarizer in order from the side closer to the light source.

The polarizing films 121 and 123 are films capable of transmitting linearly polarized light having a vibration direction parallel to a predetermined transmission axis direction and blocking other polarized light. Here, the vibration direction of linearly polarized light means the vibration direction of the electric field of linearly polarized light. The light emitted from the light source 110 is transmitted through the liquid crystal panel 120 to become linearly polarized light having a vibration direction parallel to the transmission axis A ₁₂₃ of the polarizing film 123 on the microscope side.

Moreover, the polarizing film 121 and the polarizing film 123 are arrange | positioned in the crossed Nicols state. That is, the transmission axis A ₁₂₁ of the polarizing film ₁₂₁ and the transmission axis A ₁₂₃ of the polarizing film 123 are perpendicular to each other.

  The liquid crystal cell 122 displays a right-eye pixel region (that is, a region formed by a pixel group that displays a right-eye image) 124 and a left-eye pixel region (that is, a left-eye image) as regions that can transmit light. Area 125 constituted by a pixel group to be processed). In the liquid crystal panel 120, the pixel regions 124 and 125 of the liquid crystal cell 122 also function as pixel regions of the liquid crystal panel 120 and cooperate with the polarizing films 121 and 123 to transmit light and light. It can function as both of the light shielding regions that can block the light.

  The pixel regions 124 and 125 of the liquid crystal cell 122 are regions in which pixels are formed side by side in one direction (hereinafter, referred to as “reference direction”) X in the plane. Therefore, a plurality of right-eye pixel regions 124 and left-eye pixel regions 125 are provided at different positions when viewed from the thickness direction, and both are regions extending in the in-plane reference direction X.

  Furthermore, the pixel region 124 for the right eye and the pixel region 125 for the left eye are arranged in a stripe pattern in which the pixel regions 124 and 125 are alternately arranged in a direction Y in a plane perpendicular to the reference direction X. It has become. In addition, the widths of these pixel regions 124 and 125 are usually constant.

  The pixel regions 124 and 125 serve as a reference when evaluating the linearity and pitch accuracy of the anisotropic region 133 and the isotropic region 134 of the retardation film 130. That is, when the retardation film 130 is designed so that the anisotropic region 133 and the isotropic region 134 of the retardation film 130 can be appropriately aligned with respect to the pixel regions 124 and 125, The evaluation performed in the present embodiment is to evaluate whether the retardation film 130 actually manufactured based on this is manufactured with sufficient accuracy. Therefore, it is desirable to form the reference pixel regions 124 and 125 with as high accuracy as possible.

  Between the pixel region 124 for the right eye and the pixel region 125 for the left eye of the liquid crystal cell 122, a black matrix 126 is provided as a light blocking region that can block light. The black matrix 126 is made of a material that can block light, and partitions the liquid crystal cell 122 into a plurality of pixel regions 124 and 125 in the plane. The black matrix 126 extends in the reference direction X, similarly to the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122.

  Further, in the liquid crystal cell 122, a repeating unit composed of the pixel region 124 for the right eye, the black matrix 126, the pixel region 125 for the left eye, and the black matrix 126 is repeated in the in-plane direction Y. Therefore, in the liquid crystal cell 122, the pixel regions 124 or 125 and the black matrix 126 are alternately arranged in the plane.

(Retardation film 130)
The retardation film 130 includes a first retardation film 131 and a second retardation film 132 in the order closer to the light source 110.

The first retardation film 131 is a film having a uniform retardation throughout the surface. In the present embodiment, the in-plane retardation of the first retardation film 131 is ¼ wavelength. Further, the slow axis A ₁₃₁ of the first retardation film 131 is 45 clockwise in the direction of observing the light source 110 with the microscope 150 with respect to the transmission axis A ₁₂₃ of the polarizing film 123 on the microscope side. It has an angle of °. Thereby, the linearly polarized light transmitted through the liquid crystal panel 120 is converted into circularly polarized light by transmitting through the first retardation film 131.

  The second retardation film 132 has a plurality of anisotropic regions 133 and isotropic regions 134 extending in one direction X in the plane alternately in the plane. A film having a pattern.

In the present embodiment, the in-plane retardation of the anisotropic region 133 is ½ wavelength. Further, the slow axis _{A 133} of the anisotropic region 133, the transmission axis _{A 123} of the polarizing film 123 of the microscope side, in the direction of observation towards the light source 110 a microscope 150, counterclockwise 45 It has an angle of °. Thereby, when the circularly polarized light transmitted through the first retardation film 131 is transmitted through the anisotropic region 133 of the second retardation film 132, the direction of the circularly polarized light is converted to the opposite direction.

  Further, the phase difference of the isotropic region 134 is zero. Thereby, when the circularly polarized light transmitted through the first retardation film 131 is transmitted through the isotropic region 134 of the second retardation film 132, the direction of the circularly polarized light is substantially maintained.

  When the retardation film 130 is installed on the liquid crystal panel 120, the retardation film is arranged so that the boundary line 135 between the anisotropic region 133 and the isotropic region 134 is located at a position corresponding to the black matrix 126 of the liquid crystal cell 122. 130 is aligned. As an alignment method, for example, the light source 110 emits light and the liquid crystal panel 120 is controlled so that only light that has passed through one of the right-eye pixel region 124 and the left-eye pixel region 125 is transmitted to the microscope side. There is a method of adjusting the position of the retardation film 130 while observing from the thickness direction through a circular polarizing filter in a state where the polarizing film 123 can be transmitted.

  Specifically, alignment may be performed in the following manner. First, the circularly polarized light transmitted through one of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132 is blocked, and the circularly polarized light transmitted through the other of the anisotropic region 133 and the isotropic region 134 is transmitted. Prepare a circular polarizing filter that can be used. Further, the light source 110 emits light, and light transmitted through one of the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122 is blocked by the polarizing film 123 on the microscope side, and the right-eye pixel region 124 and The liquid crystal panel 120 is controlled so that the light transmitted through the other of the left-eye pixel region 125 can pass through the polarizing film 123 on the microscope side. In this state, while observing the second retardation film 132 from the microscope side through the prepared circular polarizing filter, alignment is performed so that a black display in which no light is observed is obtained. According to this example, when the alignment is properly performed, the light transmitted through one of the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122 is transmitted through the polarizing film 123 on the microscope side. Since the light transmitted through the other of the right-eye pixel region 124 and the left-eye pixel region 125 is transmitted through one of the anisotropic region 133 and the isotropic region 134, the light is blocked by the circular polarization filter. There is no light that can pass through the circular polarizing filter. For this reason, by adjusting the position of the retardation film 130 so that a black display in which no light is observed is obtained, one of the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122 when viewed from the thickness direction Overlaps the other of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132, and the other of the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122 is the second retardation film 132. Therefore, the boundary line 135 between the anisotropic region 133 and the isotropic region 134 overlaps with the black matrix 126 of the liquid crystal cell 122, and proper alignment is achieved. it can.

  However, when the linearity or pitch accuracy of the anisotropic region 133 and the isotropic region 134 is inferior, light is always observed even if alignment is performed, and black display may not be obtained. In this case, the retardation film 130 is usually aligned at a position where the intensity of the observed light is as weak as possible. In such a position, the boundary line 135 and the black matrix 126 may not overlap in a part of the plane, but the linearity or pitch accuracy of the anisotropic region 133 and the isotropic region 134 should be evaluated. Is possible.

  In the present embodiment, when viewed from the thickness direction, the anisotropic region 133 of the second retardation film 132 overlaps the pixel region 125 for the left eye of the liquid crystal cell 122, and the isotropic region of the second retardation film 132. It is assumed that 134 is aligned so as to overlap the pixel region 124 for the right eye of the liquid crystal cell 122.

(Circularly polarizing filter 140)
The circularly polarizing filter 140 is a filter that transmits circularly polarized light in a predetermined direction and can block circularly polarized light in the opposite direction. As such a circularly polarizing filter 140, for example, a linear polarizer and a quarter wave plate are arranged such that the transmission axis of the linear polarizer and the slow axis of the quarter wave plate form an angle of 45 °. A combined film may be used. Moreover, you may form with the layer which hardened the cholesteric liquid crystal.

As the circularly polarizing filter 140 according to the present embodiment, a filter that transmits circularly polarized light in the direction indicated by the arrow A ₁₄₀ and that can block circularly polarized light in the opposite direction is used. Accordingly, the circularly polarized light transmitted through the anisotropic region 133 of the second retardation film 132 is blocked by the circular polarizing filter 140, but the circularly polarized light transmitted through the isotropic region 134 can pass through the circular polarizing filter 140. become.

  The circularly polarizing filter 140 is detachable. For this reason, the circularly polarizing filter 140 can be arbitrarily attached or detached.

(Microscope 150)
The microscope 150 is a light that can detect light that is emitted from the light source 110, transmitted through the liquid crystal panel 120 and the retardation film 130, and further transmitted through the circular polarizing filter 140 as necessary by performing observation from the thickness direction. It is a detector. Usually, a monitor (not shown) is connected to the microscope 150, and an image of the visual field of the microscope 150 is output to the monitor. Moreover, the microscope 150 is movable, and a desired position can be observed. The user performs the following evaluation method by viewing the video output to the monitor as necessary.

[1.3. Evaluation method〕
In the evaluation system described above, the retardation film 130 is evaluated. When performing the evaluation, the light source 110 is illuminated, and the liquid crystal panel 120 is further controlled to display a desired image on the liquid crystal panel 120. At this time, the pixel areas 124 and 125 where the image is displayed become light-transmitting areas and transmit light, and the pixel areas 124 and 125 and the black matrix 126 where the image is not displayed become light-shielding areas. Block out light. At this time, the image displayed on the liquid crystal panel 120 is preferably an image in which a point observed by the microscope 150 can be easily grasped.

FIG. 4 is a plan view schematically showing an image displayed on the liquid crystal panel 120 in the first embodiment of the present invention.
As shown in FIG. 4, in the present embodiment, a grid 160 is displayed on the screen 120 </ b> U of the liquid crystal panel 120. The grid 160 includes lines 161 a to 161 f parallel to the reference direction X in which the pixel regions 124 and 125 extend in the liquid crystal cell 122 and lines 162 i to 162 v perpendicular to the reference direction X. That is, a plurality of these lines 161a to 161f and lines 162i to 162v are provided at a predetermined interval, thereby forming a lattice 160. The numbers of the lines 161a to 161f parallel to the reference direction X and the lines 162i to 162v perpendicular to the reference direction X are not particularly limited, but are preferably 10 or less from the viewpoint of the number of measurement points. Books are particularly preferred.

  Each of the lines 161a to 161f parallel to the reference direction X is preferably displayed by only one of the right-eye pixel region 124 or the left-eye pixel region 125 of the liquid crystal cell 122. Thereby, it becomes easy to specify the point observed by the microscope 150. Also, it is more appropriate to examine how the amount of deviation of one pixel region 124 differs in the reference direction than to examine the difference in amount of deviation in a plurality of different pixel regions 124. it can.

In this embodiment, each line 161a parallel to the reference direction X is controlled by controlling the liquid crystal panel 120 so that the light transmitted through one pixel region 124 for the right eye can pass through the polarizing film 123 on the microscope side. ˜161f are displayed on the screen 120U of the liquid crystal panel 120. Further, a line parallel 161a~161f the reference direction X is assumed to be displayed six at regular intervals _{L 161.}

  The lines 162i to 162v perpendicular to the reference direction X are at fixed positions in the reference direction X among the pixels provided in the right-eye pixel region 124 and the left-eye pixel region 125 of the liquid crystal cell 122, for example. You may display by the row | line | column of a pixel. The column of pixels constitutes a column of pixels arranged in the direction Y perpendicular to the reference direction X, and lines 162i to 162v perpendicular to the reference direction X can be displayed by this column.

In the present embodiment, among the pixels provided in the pixel region 124 for the right eye and the pixel region 125 for the left eye, the light transmitted through the pixel at a predetermined position in the reference direction X passes through the polarizing film 123 on the microscope side. The liquid crystal panel 120 is controlled so that the lines 162 i to 162 v perpendicular to the reference direction X are displayed on the screen 120 U of the display panel 120. The vertical line 162i~162v the reference direction X is assumed to be displayed five at predetermined intervals _{L 162.}

  Further, normally, the liquid crystal cell 122 is provided with pixels corresponding to the display colors (for example, red, green, and blue) of the liquid crystal panel 120. At this time, it is preferable to combine the pixels of each display color and display the grid 160 with the combined pixels so that the grid 160 can be displayed in a color that is easy to visually recognize. In the present embodiment, the liquid crystal cell 122 is provided with a combination of red, green, and blue pixels, and the grid 160 is displayed in white using these red, green, and blue pixels.

  Observation with the microscope 150 is performed with the grid 160 displayed on the screen 120U of the liquid crystal panel 120 as described above. At this time, observation is performed in a state where the circular polarizing filter 140 is removed without being mounted, and observation is performed in a state where the circular polarizing filter 140 is mounted. Either the observation with the circular polarizing filter 140 not attached or the observation with the circular polarizing filter 140 attached may be performed first.

  The observation is performed at a point on the grid 160 displayed on the screen 120U of the liquid crystal panel 120. Usually, the intersections (for example, the intersection 163ai) of the lines 161a to 161f parallel to the reference direction X and the lines 162i to 162v perpendicular to the reference direction X are observed. This is because such an intersection can be easily identified.

FIG. 5 shows a microscopic view of the intersection 163ai between the line 161a parallel to the reference direction X and the line 162i perpendicular to the reference direction X without attaching the circular polarizing filter 140 in the first embodiment of the present invention. It is a figure which shows typically the image which appears in the visual field of a scope.
As shown in FIG. 5, when the intersection 163ai is observed without attaching the circular polarizing filter 140, the line 161a parallel to the reference direction X is represented by the red pixel R ₃ , the green pixel G ₃ and the blue pixel B _3. It is observed as a line that is repeatedly arranged in the reference direction X in this order. The line 162i perpendicular to the reference direction X is observed as a column in which a combination of pixels including the red pixel R ₃ , the green pixel G ₃ and the blue pixel B ₃ is arranged in the direction Y perpendicular to the reference direction X. Is done.

When the intersection 163ai is observed without attaching the circular polarizing filter 140, the light is transmitted through the anisotropic region 133 of the second retardation film 132 and the isotropic region 134 because the intersection 163ai is not obstructed by the circular polarizing filter 140. Both of the lights transmitted through the microscope reach the microscope 150. Therefore, the red pixel R ₃ , the green pixel G _3, and the blue pixel B ₃ constituting the grid 160 displayed on the liquid crystal panel 120 appear as they are in the visual field of the microscope 150 without being lost.

At the intersection 163ai observed in this way, a reference line 164 is set as a reference for comparison with the case of observation with the circular polarizing filter 140 attached. The reference line 164 is a line segment parallel to the reference direction X. The reference line 164 has a relative positional relationship between the reference line 164 and the red pixel R ₃ , the green pixel G _3, and the blue pixel B ₃ that are portions where light is detected at the intersection 163ai that is the observation point. Any position that can be grasped may be set. Typically, the red pixel R _3, since the relative positional relationship between the green pixel G _3, and the blue pixel B ₃ can be easily grasped, the red pixel R _3, green pixel G _3, and the blue pixel B _A reference line 164 is set as a line segment passing through the edge E ₁ in the direction Y perpendicular to the reference direction X of ₃ .

FIG. 6 shows a microscope according to the first embodiment of the present invention when the circular polarizing filter 140 is mounted and an intersection 163ai between a line 161a parallel to the reference direction X and a line 162i perpendicular to the reference direction X is observed. It is a figure which shows typically the image which appears in a visual field.
As shown in FIG. 6, when the intersection 163ai is observed with the circular polarizing filter 140 attached, the line 161a parallel to the reference direction X indicates that the red pixel R ₄ , the green pixel G _4, and the blue pixel G ₄ are partially missing. pixel B ₄ is observed as a column arranged in the reference direction X repeatedly in this order. Further, a line 162i perpendicular to the reference direction X indicates that a combination of pixels including a red pixel R ₄ , a green pixel G ₄ and a blue pixel B ₄ that are partially missing is in a direction Y perpendicular to the reference direction X. Observed as a line.

When the intersection 163ai is observed with the circular polarizing filter 140 attached, the light transmitted through the anisotropic region 133 of the second retardation film 132 is blocked by the circular polarizing filter 140, and the light transmitted through the isotropic region 134 is blocked. The light passes through the circular polarizing filter 140 and reaches the microscope 150. Therefore, in the field of view of the microscope 150, among the red pixel R ₃ , the green pixel G ₃ and the blue pixel B ₃ constituting the grid 160 displayed on the liquid crystal panel 120, the second position as viewed from the thickness direction is displayed. Only the pixel R ₄ , the pixel G _4, and the pixel B ₄ that overlap the isotropic region 134 of the phase difference film 132 appear, and the portions R ₅ , G _5, and B ₅ that overlap the anisotropic region 133 appear. Absent.

The red pixel R ₄ , the green pixel G _4, and the blue pixel B ₄ , which are the portions where the light is detected, at the intersection 163ai observed in this way are the isotropic regions 134 of the second retardation film 132. Indicates the position. The portions R ₅ , G _5, and B ₅ in which light is detected when the circular polarizing filter 140 is not attached but light is not detected when the circular polarizing filter 140 is attached are the portions of the second retardation film 132. The position of the anisotropic region 133 is shown. Here, the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G _4, and the blue pixel B ₄ , which is a portion where light is detected, is the red pixel R ₄ , This is a boundary between the green pixel G ₄ and the blue pixel B ₄ and the missing portions R ₅ , G ₅ and B ₅ . Therefore, the position of the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G _4, and the blue pixel B ₄ is the same as that of the anisotropic region 133 of the second retardation film 132. The position of the boundary line 135 with the isotropic region 134 is shown. Therefore, the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G ₄ and the blue pixel B ₄ is observed by mounting the circular polarizing filter 140 and observing the intersection 163ai. Identify the location.

Thereafter, a direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G _4, and the blue pixel B ₄ when the intersection 163ai is observed with the circular polarizing filter 140 attached thereto. measuring the displacement amount Δd of the edge E ₂ in. Here, the deviation amount Δd means a distance in a direction Y perpendicular to the reference direction X. As in this embodiment, the reference line 164 is perpendicular to the reference direction X of the red pixel R ₃ , the green pixel G _3, and the blue pixel B ₃ when the intersection 163ai is observed without attaching the circular polarizing filter 140. If you set the line segment that passes through the edge E ₁ is in the direction Y such, the deviation amount Δd is when viewed from the thickness direction, a pixel region 124 for the right eye of the liquid crystal cell 122 second retardation film The amount of deviation from the isotropic region 134 of 132 is represented.

In the first embodiment of the present invention, the above process is performed at a plurality of intersections of the grid 160, and the amount of deviation at each intersection is measured. From the viewpoint of improving the evaluation accuracy, it is preferable to perform the same process at all intersections of the grid 160.
However, the reference line is set similarly at each intersection. Here, setting the reference line similarly means that the reference line is set based on the same rule at any intersection. In the present embodiment, as shown in FIG. 5, at any intersection, the edge E ₁ in the direction Y perpendicular to the reference direction X of the red pixel R ₃ , the green pixel G _3, and the blue pixel B _3. It is assumed that a reference line is set as a line segment passing through.

  The linearity of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132 is evaluated using the deviation amount Δd at each intersection thus measured. Specifically, the linearity of the anisotropic region 133 and the isotropic region 134 is evaluated from the difference between the plurality of intersections in the reference direction X of the deviation amount Δd.

  FIG. 7 is a plan view schematically showing an image displayed on the liquid crystal panel 120 in the first embodiment of the present invention. Further, FIG. 8 shows a plurality of lines 162a to 162v in which one line 161a parallel to the reference direction X intersects with a plurality of lines 162i to 162v observed when the circular polarizing filter 140 is attached. It is a figure which shows typically the mode of intersection 163ai-163av.

  For example, as shown in FIG. 7, the difference in deviation Δd at a plurality of intersections 163ai to 163av where a single line 161a parallel to the reference direction X intersects a plurality of lines 162i to 162v perpendicular to the reference direction X is shown. It may be used. The linearity of the anisotropic region 133 and the isotropic region 134 overlapping the line 161a when viewed from the thickness direction can be evaluated by the difference in the shift amount Δd at these intersections 163ai to 163av.

  As shown in FIG. 8, at intersections 163ai to 163av, the reference line 164 is normally set to a single line common to the intersections 163ai to 163av. Accordingly, by examining how the deviation amount Δd with respect to the reference line 164 differs in the reference direction X, the straightness of the anisotropic region 133 and the isotropic region 134 can be evaluated. For example, if the amount of deviation Δd is the same at any of the intersections 163ai to 163av and the difference in the amount of deviation Δd is small, the linearity of the anisotropic region 133 and the isotropic region 134 is high, and the anisotropic region It can be seen that 133 and the isotropic region 134 extend straight in the reference direction X. Further, for example, as shown in FIG. 8, if the deviation amount Δd is greatly different for each of the intersections 163ai to 163av, and the difference in the deviation amount Δd is large, the linearity of the anisotropic region 133 and the isotropic region 134 is low, It can be seen that the anisotropic region 133 and the isotropic region 134 are bent.

Further, as described above, the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G _4, and the blue pixel B ₄ is the anisotropy of the second retardation film 132. The position of the boundary line 135 between the region 133 and the isotropic region 134 is shown. Therefore, according to the shift amount Δd of the intersections 163ai to 163av, the approximate shape of the anisotropic region 133 and the isotropic region 134 can be determined. For example, as shown in FIG. 8, when the amount of deviation Δd at the intersections 163ai, 163aiv and 163av near the end of the reference direction X is large and the amount of deviation at the intersections 163aii and 163aiii near the center of the reference direction X is small, It can be seen that the anisotropic region 133 and the isotropic region 134 of the retardation film 132 are bent in a convex arc shape on the lower side in the drawing.

  Moreover, the pitch of the anisotropic area | region 133 and the isotropic area | region 134 of the 2nd phase difference film 132 is evaluated using deviation | shift amount (DELTA) d in each intersection. Specifically, the accuracy of the total pitch of the pair of anisotropic regions 133 and isotropic regions 134 is evaluated from the difference between the plurality of intersections in the direction Y perpendicular to the reference direction X of the deviation amount Δd.

  FIG. 9 is a plan view schematically showing an image displayed on the liquid crystal panel 120 in the first embodiment of the present invention. In FIG. 9, a portion where no video is displayed is indicated by hatching. FIG. 10 shows a plurality of lines 161 a to 161 f that are observed when the circular polarizing filter 140 is attached and one line 162 i perpendicular to the reference direction X intersects the plurality of lines 161 a to 161 f. It is a figure which shows typically the mode of intersection 163ai-163fi.

  For example, as shown in FIG. 9, a difference in the amount of deviation Δd at a plurality of intersections 163ai to 163fi where a single line 162i perpendicular to the reference direction X intersects a plurality of lines 161a to 161f parallel to the reference direction X is shown. It may be used. Thereby, the difference amount of the total pitch of the anisotropic region 133 and the isotropic region 134 per distance between the intersections 163ai to 163fi can be calculated.

  In the liquid crystal cell 122, the right-eye pixel area 124, the black matrix 126, the left-eye pixel area 125, and the black matrix 126 are repeatedly arranged in the direction Y perpendicular to the reference direction X. In the second retardation film 132, the anisotropic region 133 and the isotropic region 134 are repeatedly arranged in the direction Y perpendicular to the reference direction X. Therefore, the width of the repeating unit composed of the pixel region 124 for the right eye, the black matrix 126, the pixel region 125 for the left eye, and the black matrix 126, and the total pitch of the pair of anisotropic regions 133 and isotropic regions 134 are obtained. If they are the same, the amount of deviation Δd at each of the intersections 163ai to 163fi is also the same. However, the width of the repeating unit composed of the pixel region 124 for the right eye, the black matrix 126, the pixel region 125 for the left eye, and the black matrix 126, and the total pitch of the pair of anisotropic region 133 and isotropic region 134 are as follows. If they are different, the deviation amount Δd at each of the intersections 163ai to 163fi is also different according to the difference amount.

  Therefore, by dividing the difference amount (difference) in the deviation amount Δd at two points of the intersections 163ai to 163fi by the number of pixels between the two points, a pair of anisotropic regions 133 and the second retardation film 132 and It can be seen how much the total pitch of the isotropic region 134 has an error per pixel. Here, the total pitch error means a difference between the designed total pitch size and the actual total pitch size. The magnitude of the total pitch error per pixel increases as the accuracy of the total pitch of the anisotropic region 133 and the isotropic region 134 decreases. Therefore, the accuracy of the total pitch of the anisotropic region 133 and the isotropic region 134 can be evaluated based on the magnitude of the total pitch error per pixel.

  As shown in FIG. 10, when the accuracy of the total pitch of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132 is high, the amount of deviation Δd between the two closest points among the intersections 163ai to 163fi is set. Even in comparison, the difference amount of the deviation amount Δd may not be large. If the difference amount of the deviation amount Δd is not large, the influence of the measurement error becomes large, and the magnitude of the error of the total pitch per pixel may not be obtained appropriately. In this case, it is possible to suppress the influence of the measurement error by comparing the deviation amount Δd between two points that are separated from each other among the intersections 163ai to 163fi. In particular, as in the example shown in FIG. 10, when the deviation amount Δd is smaller as it is closer to one end in the direction Y, and the deviation amount Δd is larger as it is closer to the other end, the difference amount of the deviation amount Δd is the largest. If the error of the total pitch per pixel is calculated from the difference in the shift amount Δd between the intersections 163ai and 163fi, the accuracy of the total pitch can be evaluated more accurately.

  Thus, according to the evaluation method according to the first embodiment of the present invention, the second retardation film of the retardation film 130 is based on the pixel regions 124 and 125 formed in the liquid crystal cell 122 of the liquid crystal panel 120. The linearity and pitch accuracy of the anisotropic region 133 and the isotropic region 134 included in 132 can be easily evaluated.

  The linearity of the anisotropic region 133 and the isotropic region 134 is determined by the anisotropic region 133 and the isotropic region 134 of the retardation film 130 and the pixel regions 124 and 125 of the liquid crystal panel 120 in the stereoscopic image display device. Is correlated with an assessment of whether it can be properly aligned. The alignment is correlated with the degree of crosstalk in the stereoscopic image display device. Therefore, by evaluating the linearity of the anisotropic region 133 and the isotropic region 134 as described above, the quality of the retardation film can be appropriately evaluated from the viewpoint of preventing crosstalk of the stereoscopic image display device. It is.

  In general, in order to enhance the stereoscopic image display function in the stereoscopic image display device, the anisotropic property of the retardation film 130 is adjusted according to the pixel pitch of the liquid crystal panel 120, the width of the black matrix, the thickness of the constituent material, and the appropriate viewing distance. It is required to design the pitch of the property region 133 and the isotropic region 134. For this reason, as described above, it is possible to appropriately evaluate the quality of the retardation film by evaluating how much error is present in the total pitch of the anisotropic region 133 and the isotropic region 134. Here, rather than measuring only one observation point and measuring the error of the total pitch, it is possible to make an accurate evaluation by comparing the observation points with different positions and evaluating with a wide range of deviation amount Δd.

  Furthermore, since the liquid crystal panel 120 and the liquid crystal cell 122 are usually manufactured with high accuracy by using, for example, photolithography, the above evaluation performed based on this is highly reliable.

[2. Second embodiment]
[2.1. (Target of evaluation)
The retardation film to be evaluated in the second embodiment of the present invention is the same as in the first embodiment.

[2.2. Evaluation system)
FIG. 11 is an exploded perspective view schematically showing an evaluation system according to the second embodiment of the present invention. In FIG. 11, the black stripe of the black stripe film and the anisotropic region of the second retardation film are indicated by hatching.

As shown in FIG. 11, the evaluation system 200 according to the second embodiment of the present invention is an evaluation system according to the first embodiment, except that a multilayer black stripe film 220 is provided instead of the liquid crystal panel 120 as a reference member. 100. Such an evaluation system 200 includes, for example, a retardation film to be evaluated in an evaluation apparatus including a light source 110, a multilayer black stripe film 220, a removable circular polarizing filter 140, and a microscope 150 in this order. It can be configured by attaching 130.
Here, in FIG. 11, although each element which comprises the evaluation system 200 was shown apart for illustration, some or all of these may be in the state which contacted in the actual aspect.

(Multilayer black stripe film 220)
The multilayer black stripe film 220 includes a polarizing film 221 and a black stripe film 222 which are polarizers. In the embodiment shown in FIG. 11, it is assumed that a polarizing film 221 and a black stripe film 222 that are polarizers are provided in order from the side closer to the light source 110. However, the position of the polarizing film 221 is arbitrary as long as it is closer to the light source than the first retardation film 131. For example, the polarizing film 221 may be provided on the microscope side of the black stripe film 222.

The polarizing film 221 is a film capable of transmitting linearly polarized light having a vibration direction parallel to a predetermined transmission axis direction and blocking other polarized light. By providing the polarizing film 221, the light emitted from the light source 110 passes through the multilayer black stripe film 220 and becomes linearly polarized light having a vibration direction parallel to the transmission axis A ₂₂₁ of the polarizing film 221. .

The transmission axis A ₂₂₁ of the polarizing film 221 is such that the slow axis A ₁₃₁ of the first retardation film 131 of the retardation film 130 is directed toward the light source 110 by the microscope 150 with respect to the transmission axis A ₂₂₁ of the polarizing film 221. In the observation direction, an angle of 45 ° is made clockwise. Thereby, the linearly polarized light transmitted through the multilayer black stripe film 220 is converted into circularly polarized light by transmitting through the first retardation film 131.

Further, the transmission axis _{A 221} of the polarizing film 221, the slow axis _{A 133} of the anisotropic region 133 of the second retardation film 132, the transmission axis _{A 221} of the polarizing film 221, the light source 110 a microscope 150 An angle of 90 ° is made clockwise in the direction of observing toward. Thereby, when the circularly polarized light transmitted through the first retardation film 131 is transmitted through the anisotropic region 133 of the second retardation film 132, the direction of the circularly polarized light is converted to the opposite direction.

The black stripe film 222 is a film including a substrate 223 that can transmit light emitted from the light source 110 and a black stripe 224 that is formed on the substrate 223 and extends in parallel with the reference direction X.
As the substrate 223, for example, a material having a thickness of 1 mm and a total light transmittance (measured using a turbidimeter (manufactured by Nippon Denshoku Industries Co., Ltd., NDH-300A) based on JIS K7361-1997) of 80% or more. What was formed by may be used, for example, a glass plate etc. are mentioned.
The black stripe 224 is formed of a material that can block light emitted from the light source 110 and functions as a light shielding region. In the black stripe film 222, a region where the black stripe is not formed between the black stripes 224 is a light transmitting region 225, and light emitted from the light source 110 is transmitted through the light transmitting region 225. It has become possible.

  A plurality of black stripes 224 and translucent regions 225 are provided at different positions when viewed from the thickness direction, and both are regions extending in the in-plane reference direction X. Further, the black stripes 224 and the light-transmitting regions 225 are arranged in a stripe shape alternately arranged in a direction Y in a plane perpendicular to the reference direction X. Further, the widths of the black stripe 224 and the light transmitting region 225 are usually constant.

  The black stripe 224 and the translucent region 225 serve as a reference when evaluating the linearity and pitch accuracy of the anisotropic region 133 and the isotropic region 134 of the retardation film 130. That is, the phase difference is adjusted so that the anisotropic region and the isotropic region 134 of the retardation film 130 can be properly aligned with respect to the liquid crystal panel having a pixel region corresponding to the black stripe 224 and the light transmitting region 225. When the film 130 is designed, the evaluation performed in this embodiment is to evaluate whether the retardation film 130 actually manufactured based on the design is manufactured with sufficient accuracy. Therefore, the black stripe 224 serving as a reference is preferably set according to the liquid crystal panel of the liquid crystal display device to which the retardation film 130 is applied, and is preferably formed with as high accuracy as possible.

  When the retardation film 130 is installed on the multilayer black stripe film 220, in this embodiment, the anisotropic region 133 is located at a position corresponding to the black stripe 224, and the isotropic region 134 is placed in the light transmitting region 225. The retardation film 130 is aligned so as to come to the corresponding position. Examples of the alignment method include a method of adjusting the position of the retardation film 130 while observing from the thickness direction through a circular polarizing filter in a state where the light source 110 emits light.

  Specifically, alignment may be performed in the following manner. First, a circularly polarizing filter capable of blocking the circularly polarized light transmitted through the isotropic region 134 of the second retardation film 132 is prepared. Further, the light source 110 is caused to emit light. In this state, while observing the second retardation film 132 from the side opposite to the light source 110 through the prepared circular polarizing filter, alignment is performed so that a black display in which no light is observed is obtained. According to this example, when the alignment is properly performed, the light transmitted through the light transmitting region 225 of the black stripe film 222 is blocked by the circular polarization filter, and the other light is blocked by the black stripe 224. The light that can be transmitted through the circular polarizing filter is lost. For this reason, the black stripe 224 of the black stripe film 222 is anisotropy of the second retardation film 132 when viewed from the thickness direction by adjusting the position of the retardation film 130 so that a black display in which no light is observed is obtained. Overlapping with the region 133, the translucent region 225 of the black stripe film 222 overlaps with the isotropic region 134 of the second retardation film 132, and appropriate alignment can be performed. When the black stripe 224 is to be overlapped with the isotropic region 134, the alignment may be performed in the same manner using a circular polarizing filter that can block the circularly polarized light transmitted through the anisotropic region 133.

  However, when the linearity or pitch accuracy of the anisotropic region 133 and the isotropic region 134 is inferior, light is always observed even if alignment is performed, and black display may not be obtained. In this case, as in the first embodiment, the retardation film is aligned at a position where the amount of observed light is as small as possible.

[2.3. Evaluation method〕
In the evaluation system described above, the retardation film 130 is evaluated. When performing the evaluation, the light source 110 is illuminated.

FIG. 12 is a plan view schematically showing a state in which the multilayer black stripe film 220 is viewed from the microscope side in the second embodiment of the present invention.
As shown in FIG. 12, in this embodiment, since the black stripe 224 blocks light, only the light that has passed through the light transmitting portion 225 of the black stripe film 222 passes through the multilayer black stripe film 220.

  In such a state, observation with the microscope 150 is performed. At this time, observation is performed in a state where the circular polarizing filter 140 is removed without being mounted, and observation is performed in a state where the circular polarizing filter 140 is mounted. Either the observation with the circular polarizing filter 140 not attached or the observation with the circular polarizing filter 140 attached may be performed first.

FIG. 13 schematically shows an image that appears in the field of view of a microscope when a point 260ai of the multilayer black stripe film 220 is observed without attaching the circular polarizing filter 140 in the second embodiment of the present invention. FIG.
As shown in FIG. 13, when the point 260ai on the light transmission region 225 of the multilayer black stripe film 220 is observed without attaching the circular polarizing filter 140, the light is detected, and the light is not detected. A dark portion 262 is observed. The bright portion 261 corresponds to the light-transmitting region 225 of the black stripe film 222, and the dark portion 262 corresponds to the black stripe 224. Each of the bright portions 261 is observed as a strip-like portion parallel to the reference direction X.

At the point 260ai observed in this way, a reference line 263 is set as a reference for comparison with the case of observation with the circular polarizing filter 140 attached. The reference line 263 is a line segment parallel to the reference direction X. The reference line 263 may be set to any position as long as the relative positional relationship between the bright portion 261 where light is detected at the observed point 260ai and the reference line 263 can be grasped. . Normally, since the relative positional relationship between the bright portion 261 can be easily grasped, as a line passing through the edge E ₃ in the direction perpendicular Y to the reference direction X in the bright portion 261 sets the reference line 263.

FIG. 14 is a diagram schematically showing an image that appears in the field of view of the microscope when the circular polarizing filter 140 is attached and the point 260ai of the multilayer black stripe film 220 is observed in the second embodiment of the present invention. is there.
As shown in FIG. 14, when the circular polarizing filter 140 is attached and the point 260ai of the multilayer black stripe film 220 is observed, a portion 264 in the direction Y perpendicular to the reference direction X of the bright portion 261 is missing, and the bright portion 261 state in which the position of the edge E ₄ in the direction Y is changed is observed.

  When the point 260ai of the multilayer black stripe film 220 is observed with the circular polarizing filter 140 attached, the light transmitted through the anisotropic region 133 of the second retardation film 132 is blocked by the circular polarizing filter 140 and isotropic. The light transmitted through the region 134 passes through the circular polarizing filter 140 and reaches the microscope 150. Therefore, in the field of view of the microscope 150, only the portion of the light transmitting region 225 of the black stripe film 222 that overlaps the isotropic region 134 of the second retardation film 132 as viewed from the thickness direction is a bright portion 261. The portion that appears and overlaps with the anisotropic region 133 becomes a dark portion 262.

The bright portion 261 where light is detected at the point 260ai of the multilayer black stripe film 220 thus observed indicates the position of the isotropic region 134 of the second retardation film 132. The portion 264 in which light is detected when the circular polarizing filter 140 is not attached but is not detected when the circular polarizing filter 140 is attached is the position of the anisotropic region 133 of the second retardation film 132. Indicates. Here, the edge portion E ₄ in the perpendicular direction Y to the reference direction X of the bright portion 261 where the light is detected, a bright portion 261, which is the boundary between the chipped portions 264. Therefore, the position of the edge E ₄ in the direction Y perpendicular to the reference direction X of the bright portion 261 where the light is detected is the boundary line between the anisotropic region 133 and the isotropic region 134 of the second retardation film 132. The position of 135 is shown. Therefore, by observing the point 260ai of multilayer black stripe film 220 wearing the circularly polarizing filter 140, the position of the edge E ₄ in the perpendicular direction Y to the reference direction X of the bright portion 261 where the light is detected Identify.

After that, the reference line 263 and the edge in the direction Y perpendicular to the reference direction X of the bright part 261 where the light is detected when the circular polarizing filter 140 is attached and the point 260ai of the multilayer black stripe film 220 is observed The amount of deviation Δd from the part E ₄ is measured. As in this embodiment, the edge E in the direction Y perpendicular to the reference direction X of the bright portion 261 when the point 260ai of the multilayer black stripe film 220 is observed as the reference line 263 without attaching the circular polarizing filter 140. ₃ is set, the deviation amount Δd is the difference between the translucent region 225 of the black stripe film 222 and the isotropic region 134 of the second retardation film 132 when viewed from the thickness direction. Indicates the amount of deviation.

  In the second embodiment of the present invention, the above process is performed at a plurality of points 260ai to 260aiii, 260bi and 260ci of the multilayer black stripe film 220, and the amount of deviation at each point 260ai to 260aiii, 260bi and 260ci is measured. At this time, in order to evaluate the linearity of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132, the position (coordinates) in the reference direction X is different, and the direction Y is perpendicular to the reference direction X. The shift amount is measured at a plurality of points 260ai to 260aiii having the same position (coordinates). In addition, in order to evaluate the accuracy of the pitch of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132, the direction Y in the reference direction X is the same and the direction Y is perpendicular to the reference direction X. The shift amount is measured at a plurality of points 260ai to 260ci having different positions (coordinates).

However, the reference line 263 is similarly set at each of the points 260ai to 260aiii, 260bi, and 260ci. In the present embodiment, as shown in FIG. 13, any point 260Ai～260aiii, even 260bi and 260Ci, as a line passing through the edge _{E 3} in the direction perpendicular Y to the reference direction X in the bright portion 261, the reference line Assume that H.263 is set.

  The linearity of the anisotropic region 133 and the isotropic region 134 of the second retardation film 132 is evaluated using the deviation amount Δd at each of the points 260ai to 260aiii thus measured. Specifically, as in the first embodiment, the linearity of the anisotropic region 133 and the isotropic region 134 is evaluated from the difference between the plurality of points 260ai to 260aiii in the reference direction X of the deviation amount Δd. To do.

  For example, a difference in the amount of deviation Δd at a plurality of points 260ai to 260aiii on one translucent region 225 of the black stripe film 222 may be used. If the deviation amount Δd is the same at any of the points 260ai to 260aiii and the difference in the deviation amount Δd is small, the straightness of the anisotropic region 133 and the isotropic region 134 is high, and the anisotropic region 133 and It can be seen that the isotropic region 134 extends straight in the reference direction X. Further, if the deviation amount Δd is greatly different for each point 260ai to 260aiii and the difference in the deviation amount Δd is large, the straightness of the anisotropic region 133 and the isotropic region 134 is low, and the anisotropic region 133 and the like are the same. It can be seen that the anisotropic region 134 is bent.

  Furthermore, as described in the first embodiment, according to the shift amount Δd at the plurality of points 260ai to 260aiii on the single translucent region 225 of the black stripe film 222, the anisotropic region 133 and the isotropic property are obtained. An approximation of the approximate shape of region 134 can be made.

  Moreover, the pitch of the anisotropic area | region 133 and the isotropic area | region 134 of the 2nd phase difference film 132 is evaluated using deviation | shift amount (DELTA) d in each point 260ai-260ci. Specifically, in the same manner as in the first embodiment, the anisotropic region 133 and the isotropic region 134 are derived from the difference between the plurality of points 260ai to 260ci in the direction Y perpendicular to the reference direction X of the deviation amount Δd. Evaluate pitch accuracy.

  For example, the difference in misregistration amount Δd at a plurality of points 260ai to 260ci having the same position (coordinates) in the reference direction X and different positions (coordinates) in the direction Y perpendicular to the reference direction X of the multilayer black stripe film 220. May be used. By dividing the difference (difference) in the shift amount Δd between the two points 260ai to 260ci of the multilayer black stripe film 220 by the number of pixels between the two points, the anisotropic region 133 of the second retardation film 132 and It can be seen how much the total pitch of the isotropic region 134 has an error per pixel. The accuracy of the total pitch of the anisotropic region 133 and the isotropic region 134 can be evaluated by the magnitude of the error of the total pitch per pixel.

  However, unlike the first embodiment, the multilayer black stripe film 220 as the reference member does not have a pixel region. Therefore, when evaluating the accuracy of the pitch, it is preferable to convert the distance between two points for comparing the deviation amount Δd into the number of pixels in advance.

  As described above, according to the evaluation method according to the second embodiment of the present invention, the retardation film is based on the black stripe 224 and the light transmitting region 225 formed on the black stripe film 222 of the multilayer black stripe film 220. The linearity and pitch accuracy of the anisotropic region 133 and the isotropic region 134 included in the 130 second retardation film 132 can be easily evaluated. Since the black stripe 224 of the black stripe film 222 can be formed with high accuracy by using, for example, photolithography or the like, the above evaluation performed based on this has high reliability.

[3. Third embodiment]
[3.1. (Target of evaluation)
The retardation film to be evaluated in the third embodiment of the present invention is a film having a plurality of anisotropic regions with different slow axis directions. These regions are formed at different positions when viewed from the thickness direction of the retardation film.

  An example of a suitable combination of anisotropic regions is a combination of two types of regions in which the slow axis direction is vertical. Here, the phrase that the slow axis direction is perpendicular means that the angle formed by these slow axis directions is usually within 90 ° ± 5 °, preferably within 90 ° ± 1 °. Specific examples of the combination include a combination of a region in which the slow axis direction is parallel to the longitudinal direction of the retardation film and a region perpendicular thereto, and a slow axis direction of +45 relative to the longitudinal direction of the retardation film. A combination of a region forming an angle of ° and a region forming an angle of -45 ° may be mentioned.

  Usually, the in-plane retardation of each anisotropic region is the same. That is, normally, the retardation film to be evaluated in the third embodiment has a plurality of types of anisotropic regions having different in-plane retardations but different slow axis directions. The specific phase difference in the anisotropic region may be, for example, a quarter wavelength.

  The retardation film has a plurality of first anisotropic regions each having a slow axis in a certain slow axis direction, and a plurality of second anisotropic regions each having a slow axis in a different slow axis direction. . These anisotropic regions are formed extending in one direction. Further, the first anisotropic region and the second anisotropic region are alternately arranged in the direction intersecting the extending direction, and constitute a pattern according to the use of the retardation film as a whole. Usually, since a retardation film is used in combination with a liquid crystal panel of a liquid crystal display device, a specific pattern of each anisotropic region is set according to the arrangement of pixels of the liquid crystal panel. For example, when applied to a passive stereoscopic image display device, a region corresponding to one of a pixel group displaying a right-eye image and a pixel group displaying a left-eye image is the first anisotropic region. The pattern corresponding to the other anisotropic region may be a pattern corresponding to the other.

  When the retardation film has two groups of anisotropic regions, a first anisotropic region and a second anisotropic region, these anisotropic regions are striped as described in the first embodiment. You may make it have the following pattern. At this time, the alignment is usually performed so that the boundary line of these anisotropic regions is positioned on the black stripe of the liquid crystal panel.

  When such alignment is performed, if the linearity of each isotropic region is impaired or the pitch accuracy is lowered, the boundary line between the anisotropic regions cannot be located on the black matrix, which is desired. 3D image display device cannot be manufactured, and crosstalk occurs, which may cause defective products.

  Therefore, if the linearity and pitch accuracy of the anisotropic region of the retardation film are evaluated, and whether or not the retardation film can be properly aligned is determined, a stereoscopic image display device can be obtained. Generation of defective products can be suppressed. At this time, if the evaluation method according to the third embodiment of the present invention is used, the retardation film can be easily evaluated.

  In addition, like the phase difference film which concerns on 1st embodiment, the phase difference film may be equipped with arbitrary layers, unless the effect of this invention is impaired remarkably.

[3.2. Evaluation system)
FIG. 15 is an exploded perspective view schematically showing an evaluation system according to the third embodiment of the present invention. In FIG. 15, the pixel region for the left eye of the liquid crystal cell and the second anisotropic region of the retardation film are indicated by hatching.

As shown in FIG. 15, the evaluation system 300 according to the third embodiment of the present invention is the same as the evaluation system 100 according to the first embodiment, except that the retardation film 330 is provided instead of the retardation film 130. is there. In such an evaluation system 300, for example, a retardation film 330 to be evaluated is attached to an evaluation apparatus including a light source 110, a liquid crystal panel 120, a detachable circular polarizing filter 140, and a microscope 150 in this order. Can be configured.
Here, in FIG. 15, all the elements constituting the evaluation system 300 are shown apart from each other for illustration, but some or all of them may be in contact with each other in an actual aspect.

(Retardation film 330)
The retardation film 330 has a plurality of first anisotropic regions 331 and second anisotropic regions 332 extending in one direction X in the plane, and thus has a stripe-like pattern composed of these regions. It is. In the present embodiment, the in-plane retardation of the first anisotropic region 331 and the second anisotropic region 332 are both ¼ wavelength.

The slow axis _{A 331} of the first anisotropic region 331 to the transmission axis _{A 123} of the polarizing film 123 of the microscope side, in the direction of observation towards the light source 110 a microscope 0.99, 45 ° clockwise The angle is made. Accordingly, the linearly polarized light transmitted through the liquid crystal panel 120 is converted into circularly polarized light that can be transmitted through the circular polarizing filter 140 by transmitting through the first anisotropic region 331 of the retardation film 330. Yes.

Further, the slow axis _{A 332} of the second anisotropic region 332, the transmission axis _{A 123} of the polarizing film 123 of the microscope side, in the direction of observation towards the light source 110 a microscope 150, counterclockwise The angle is 45 °. As a result, the linearly polarized light transmitted through the liquid crystal panel 120 is transmitted through the second anisotropic region 332 of the retardation film 330, thereby being polarized in the opposite direction to the circularly polarized light transmitted through the first anisotropic region 331. It is converted into circularly polarized light blocked by the filter 140.

  When the retardation film 330 is installed on the liquid crystal panel 120, the boundary line 333 between the first anisotropic region 331 and the second anisotropic region 332 is located at a position corresponding to the black matrix 126 of the liquid crystal cell 122. The phase difference film 330 is aligned. As an alignment method, for example, as in the first embodiment, the light source 110 emits light, and the liquid crystal panel 120 is controlled to transmit one of the right-eye pixel region 124 and the left-eye pixel region 125. A method of adjusting the position of the retardation film 330 while observing from the thickness direction through a circular polarizing filter in a state where only the light that has been transmitted can pass through the polarizing film 123 on the microscope side can be mentioned.

  However, when the linearity or pitch accuracy of the first anisotropic region 331 and the second anisotropic region 332 is inferior, light is always observed even if alignment is performed, and black display may not be obtained. It can be. In this case, the retardation film 330 is usually aligned at a position where the intensity of the observed light is as weak as possible. In such a position, the boundary line 333 and the black matrix 126 may not overlap each other in a part of the plane, but the linearity or pitch accuracy of the first anisotropic region 331 and the second anisotropic region 332 is not possible. It is possible to evaluate

  In the present embodiment, when viewed from the thickness direction, the first anisotropic region 331 of the retardation film 330 overlaps the pixel region 124 for the right eye of the liquid crystal cell 122, and the second anisotropic region 332 is the liquid crystal cell 122. Are aligned so as to overlap the pixel region 125 for the left eye.

[3.3. Evaluation method〕
In the evaluation system described above, the retardation film 330 is evaluated.
When the polarizing filter 140 is attached and observed, the light transmitted through the anisotropic region 133 of the second retardation film 132 in the first embodiment is blocked by the polarizing filter 140 in the third embodiment. The light transmitted through the second anisotropic region 332 of the retardation film 330 is blocked by the polarizing filter 140. Further, in the first embodiment, the light transmitted through the isotropic region 134 of the second retardation film 132 is transmitted through the polarizing filter 140 and reaches the microscope 150. In the third embodiment, the retardation film is used. The light transmitted through the first anisotropic region 331 of 330 is transmitted through the polarizing filter 140 and reaches the microscope 150. Therefore, the retardation film 330 according to the third embodiment has the first anisotropic region 331 as an element corresponding to the isotropic region 134 according to the first embodiment, and the second anisotropic region 332. Can be treated as an element corresponding to the anisotropic region 133 according to the first embodiment, and evaluated in the same manner as in the first embodiment.

Specifically, when evaluating the linearity of the first anisotropic region 331 and the second anisotropic region 332 of the retardation film 330, the following operation is performed.
In a state where the grid 160 is displayed on the screen 120U of the liquid crystal panel 120, a plurality of intersections 163ai to 163av (see FIG. 7) of the grid 160 are observed with the microscope 150 without attaching the polarizing filter 140. A filter 140 is attached and observed with a microscope 150. From the result of observation without attaching the polarizing filter 140, the reference line 164 parallel to the reference direction X is similarly set at a plurality of intersections 163ai to 163av. Further, from the result of observation with the polarizing filter 140 attached, the reference line 164 and the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G ₄ and the blue pixel B ₄ Is measured (see FIG. 6). Then, the linearity of the first anisotropic region 331 and the second anisotropic region 332 of the retardation film 330 is evaluated from the difference between the plurality of intersections 163ai to 163av in the deviation amount Δd.

Further, when evaluating the total pitch of the pair of first anisotropic regions 331 and second anisotropic regions 332 in the retardation film 330, the following operation is performed.
In a state where the grid 160 is displayed on the screen 120U of the liquid crystal panel 120, a plurality of intersections 163ai to 163fi (see FIG. 9) of the grid 160 are observed with the microscope 150 without attaching the polarizing filter 140. A filter 140 is attached and observed with a microscope 150. From the result of observation without attaching the polarizing filter 140, the reference line 164 parallel to the reference direction X is similarly set at a plurality of intersections 163ai to 163av. Further, from the result of observation with the polarizing filter 140 attached, the reference line 164 and the edge E ₂ in the direction Y perpendicular to the reference direction X of the red pixel R ₄ , the green pixel G ₄ and the blue pixel B ₄ Is measured (see FIG. 6). Then, by dividing the difference amount between the plurality of intersections 163ai to 163fi in the deviation amount Δd by the number of pixels between the two points to be compared, a set of the first anisotropic region 331 and the second anisotropic region 332 is obtained. An error per pixel of the total pitch of the first anisotropic region 331 and the second anisotropic region 332 is evaluated to evaluate the accuracy of the total pitch.

  Thus, according to the evaluation method according to the third embodiment of the present invention, the first anisotropy of the retardation film 330 is based on the pixel regions 124 and 125 formed in the liquid crystal cell 122 of the liquid crystal panel 120. The linearity and pitch accuracy of the region 331 and the second anisotropic region 332 can be easily evaluated.

[4. Fourth embodiment]
[4.1. (Target of evaluation)
The retardation film to be evaluated in the fourth embodiment of the present invention is the same as in the third embodiment.

[4.2. Evaluation system)
FIG. 16 is an exploded perspective view schematically showing an evaluation system according to the fourth embodiment of the present invention. In FIG. 16, the black stripe of the black stripe film and the second anisotropic region of the retardation film are indicated by hatching.

As shown in FIG. 16, the evaluation system 400 according to the fourth embodiment of the present invention is the same as the evaluation system 200 according to the second embodiment, except that the retardation film 330 is provided instead of the retardation film 130. is there. Such an evaluation system 400 includes, for example, a retardation film to be evaluated in an evaluation apparatus including a light source 110, a multilayer black stripe film 220, a removable circular polarizing filter 140, and a microscope 150 in this order. It can be configured by attaching 330.
Here, in FIG. 16, each element constituting the evaluation system is shown separated for illustration, but some or all of them may be in contact with each other in an actual aspect.

(Retardation film 330)
The retardation film 330 is the same as that described in the third embodiment, and has a stripe shape including a plurality of first anisotropic regions 331 and second anisotropic regions 332 extending in one direction X in the plane. It is a film which has the pattern of.

The slow axis _{A 331} of the first anisotropic region 331 to the transmission axis _{A 221} of the polarizing film 221, in the direction of observation towards the light source 110 a microscope 150, an angle of 45 ° clockwise ing. Accordingly, the linearly polarized light transmitted through the multilayer black stripe film 220 is converted into circularly polarized light that can be transmitted through the polarizing filter 140 by transmitting through the first anisotropic region 331 of the retardation film 330. It has become.

Further, the slow axis _{A 332} of the second anisotropic region 332, the transmission axis _{A 221} of the polarizing film 221, in the direction of observation towards the light source 110 a microscope 150, a 45 ° counterclockwise It makes an angle. Accordingly, the linearly polarized light transmitted through the multilayer black stripe film 220 is transmitted in the opposite direction to the circularly polarized light transmitted through the first anisotropic region 331 by transmitting through the second anisotropic region 332 of the retardation film 330. The light is converted into circularly polarized light blocked by the polarizing filter 140.

  When the retardation film 330 is placed on the multilayer black stripe film 220, in the present embodiment, the first anisotropic region 331 is located at a position corresponding to the light transmission region 225 of the black stripe film 222, and the second The retardation film 130 is aligned so that the isotropic region 332 is located at a position corresponding to the black stripe 224. As an alignment method, for example, as in the second embodiment, there is a method of adjusting the position of the retardation film 330 while observing from the thickness direction through a circular polarizing filter in a state where the light source 110 emits light. Can be mentioned.

  However, when the linearity or pitch accuracy of the first anisotropic region 331 and the second anisotropic region 332 is inferior, light is always observed even if alignment is performed, and black display may not be obtained. It can be. In this case, as in the first embodiment, the retardation film is aligned at a position where the amount of observed light is as small as possible.

[4.3. Evaluation method〕
In the evaluation system described above, the retardation film 330 is evaluated.
When the polarizing filter 140 is mounted and observed, the light transmitted through the anisotropic region 133 of the second retardation film 132 in the second embodiment is blocked by the polarizing filter 140 in the fourth embodiment. The light transmitted through the second anisotropic region 332 of the retardation film 330 is blocked by the polarizing filter 140. Further, in the second embodiment, the light transmitted through the isotropic region 134 of the second retardation film 132 is transmitted through the polarizing filter 140 and reaches the microscope 150. In the fourth embodiment, the retardation film is used. The light transmitted through the first anisotropic region 331 of 330 is transmitted through the polarizing filter 140 and reaches the microscope 150. Therefore, the retardation film 330 according to the fourth embodiment has the first anisotropic region 331 as an element corresponding to the isotropic region 134 according to the second embodiment, and the second anisotropic region 332. Can be treated as an element corresponding to the anisotropic region 133 according to the second embodiment, and evaluated in the same manner as in the second embodiment.

Specifically, when evaluating the linearity of the first anisotropic region 331 and the second anisotropic region 332 of the retardation film 330, the following operation is performed.
With the light source 110 illuminated, a plurality of points 260ai to 260aiii (see FIG. 12) on the translucent region 225 of the multilayer black stripe film 220 are observed with the microscope 150 without attaching the polarizing filter 140, and Then, the polarizing filter 140 is attached and the microscope 150 is used for observation. At this time, as the plurality of observed points 260ai to 260aiii, points having different positions (coordinates) in the reference direction X but having the same position (coordinates) in the direction Y perpendicular to the reference direction X are selected. From a result of observation without attaching the polarizing filter 140, a reference line 263 parallel to the reference direction X is set similarly at a plurality of points 260ai to 260aiii. Further, measured from the results of the observation fitted with polarizing filter 140, the reference line 263, the deviation amount Δd of the edge _{E 4} in the direction Y of the bright portion 261 (see FIG. 14). Then, the linearity of the first anisotropic region 331 and the second anisotropic region 332 of the retardation film 330 is evaluated from the difference between the plurality of points 260 in the deviation amount Δd.

Further, when evaluating the total pitch of the pair of first anisotropic regions 331 and second anisotropic regions 332 in the retardation film 330, the following operation is performed.
With the light source 110 illuminated, a plurality of 260ai to 260ci (see FIG. 12) on the light transmitting region 225 of the multilayer black stripe film 220 are observed with the microscope 150 without attaching the polarizing filter 140, A polarizing filter 140 is attached and observed with a microscope 150. At this time, as the plurality of observed points 260ai to 260ci, points having the same position (coordinates) in the reference direction X but different positions (coordinates) in the direction Y perpendicular to the reference direction X are selected. . From a result of observation without attaching the polarizing filter 140, a reference line 263 parallel to the reference direction X is similarly set at a plurality of points 260ai to 260ci. Further, measured from the results of the observation fitted with polarizing filter 140, the reference line 263, the deviation amount Δd of the edge _{E 4} in the direction Y of the bright portion 261 (see FIG. 14). The difference amount Δd between the plurality of points 260ai to 260ci is divided by the number of pixels between the two points to be compared, so that a pair of the first anisotropic region 331 and the second anisotropic region 332 are obtained. An error per pixel of the total pitch of the first anisotropic region 331 and the second anisotropic region 332 is evaluated to evaluate the accuracy of the total pitch.

  As described above, according to the evaluation method according to the fourth embodiment of the present invention, the retardation film is based on the black stripe 224 and the light transmitting region 225 formed on the black stripe film 222 of the multilayer black stripe film 220. The linearity and pitch accuracy of 130 first anisotropic regions 331 and second anisotropic regions 332 can be easily evaluated.

[5. Modified example]
The above-described embodiment may be further modified and implemented.
For example, the direction of the optical axis in each embodiment may be arbitrarily changed as long as the retardation film can be appropriately evaluated. For example, in the evaluation system of Figure 3, the transmission axis _{A 123} of the polarizing film 123 of the microscope side, the relationship between the transmission axis _{A 121} and the slow axis _{A 131} of the first retardation film of the polarizing film 121 of the light source side You may make it make an angle of 90 degrees with respect to the reference direction X in a surface, hold | maintaining.
Further, for example, in each embodiment, a linear polarizing filter capable of transmitting or blocking linearly polarized light may be used as the polarizing filter by providing a quarter wavelength plate on the microscope side of the retardation film.
In addition, for example, the quarter wavelength plate in each embodiment includes a wideband quarter wavelength plate in which a plurality of retardation films are laminated so that the optical axis of the retardation film has a desired relationship, and an inverse wavelength dispersion liquid crystal. A broadband quarter-wave plate formed by applying to a substrate may be used.

Further, for example, in the evaluation system 100 according to the first embodiment, the anisotropic region 133 of the second retardation film 132 and the pixel region 124 for the right eye of the liquid crystal cell 122 and the pixel region 125 for the left eye, respectively, You may align so that the isotropic area | region 134 may overlap.
Further, for example, the alignment with the liquid crystal panel may be performed using an alignment mark or the like provided on the outer periphery other than the effective area of the first retardation film.
Further, for example, in the evaluation system 100 according to the first embodiment, the direction of the circularly polarized light that can be transmitted through the circularly polarizing filter may be reversed. In this case, in the observation with the circular polarizing filter 140 attached, the deviation Δd is measured and evaluated by detecting the light transmitted through the anisotropic region 133.

For example, in the evaluation systems 100 and 300 according to the first embodiment and the third embodiment, the image displayed on the liquid crystal panel 120 may be an image other than the lattice 160.
Further, for example, in the evaluation systems 100 and 200 according to the first embodiment and the third embodiment, light may be transmitted only by some display color pixels of the liquid crystal panel 120.

In addition, for example, in the evaluation system 200 according to the second embodiment, the anisotropic region 133 of the second retardation film 132 may overlap the light transmitting region 225 of the black stripe film 222. In this case, instead of the circular polarizing filter 140, a circular polarizing filter capable of transmitting circularly polarized light in the direction opposite to the circular polarizing filter 140 is used.
Further, for example, in the evaluation systems 200 and 400 according to the second embodiment and the fourth embodiment, the polarizing film 221 may be provided on the microscope side with respect to the black stripe film 222.

  Further, for example, in the evaluation system 400 according to the fourth embodiment, the second anisotropic region 332 of the retardation film 330 may overlap the light transmitting region 225 of the black stripe film 222. In this case, instead of the circular polarizing filter 140, a circular polarizing filter capable of transmitting circularly polarized light in the direction opposite to the circular polarizing filter 140 is used.

Further, for example, in the evaluation systems 200 and 400 according to the second embodiment and the fourth embodiment, as a reference member, instead of the multilayer black stripe film 220, a light-transmitting region and a light-shielding region constituting a stripe pattern are provided. A glass mask provided on glass may be used. For example, the glass mask may be formed by performing chromium sputtering on the glass surface, further applying a photoresist, exposing the photoresist in a stripe shape, exposing the photoresist, washing, and etching chromium. Alternatively, for example, a PET film coated with a photosensitive emulsion may be laser-drawn in a stripe shape, washed, and the PET film bonded onto glass via an adhesive layer may be used as the reference member.
Furthermore, as long as the retardation film can be appropriately evaluated, an arbitrary component may be added to the evaluation system.

[6. Material etc.]
Then, the example of the material which comprises the member used in the evaluation method mentioned above is demonstrated below.

[6-1. Polarizer and Polarizing Filter]
As the polarizer and the polarizing filter, a polarizing plate that transmits desired polarized light and can block other polarized light may be used.
Among the polarizing plates, the linear polarizing plate may be produced, for example, by adsorbing iodine or a dichroic dye to a polyvinyl alcohol film and then uniaxially stretching in a boric acid bath. Alternatively, for example, iodine or a dichroic dye may be adsorbed and stretched on a polyvinyl alcohol film, and a part of the polyvinyl alcohol unit in the molecular chain may be modified to a polyvinylene unit.

Examples of the circularly polarizing plate include a polarizing plate obtained by combining the above-described linearly polarizing plate and a quarter wavelength plate. However, when using the circularly-polarizing plate which combined the linearly-polarizing plate mentioned above and the quarter wavelength plate, it is preferable to arrange | position the quarter wavelength plate so that it may face the phase difference film side.
Further, as the circularly polarizing plate, for example, a cholesteric liquid crystal polarizing plate (for example, “cholesteric resin layer” described in JP 2010-181710 A) may be used.
The polarization degree of the polarizing plate is preferably 98% or more, more preferably 99% or more.

[6-3. Reference member]
As the reference member, for example, a liquid crystal panel and a multilayer black stripe film may be used as in the above-described embodiment. In these reference members, a light shielding region is usually formed by a black stripe that can block light detected by a detector, and a region in which the black stripe is not formed can function as a light transmitting region. In the liquid crystal panel, some pixel regions may function as a light-transmitting region or may function as a light-shielding region depending on an image to be displayed.

  For example, the black stripe may be formed of a resin capable of blocking visible light. Specific examples include a resin containing a colorant or metal particles.

  Examples of the resin include acrylic resin, urethane resin, polyamide resin, cellulose ester resin, polyester resin, polyimide resin, polyamideimide resin, urethane acrylate cured resin, epoxy acrylate cured resin, and polyester acrylate cured resin. These resins may be used alone or in combination of two or more at any ratio.

  Examples of the colorant include organic pigments, carbon black pigments, conductive carbon blacks, battery carbon blacks, rubber carbon blacks, and the like; anthraquinone compounds, phthalocyanine compounds, perinone compounds, dioxazine compounds, benzofuran compounds. And dyes such as compounds, thiophene monoazo compounds, cyanine compounds, and diimmonium compounds. These colorants may be used alone or in combination of two or more at any ratio.

  Examples of the metal material forming the metal particles include nickel, platinum, palladium, silver-palladium, copper, gold, silver, tin, lead, and alloys thereof. These metal materials may be used alone or in combination of two or more at any ratio. Moreover, the surface treatment may be given to the metal particle, for example, the surface may be modified by the thiol compound. The particle diameter (diameter) of the metal particles is preferably in the range of 0.2 μm or more and 60 μm or less.

[6-4. A retardation film comprising a first retardation film and a second retardation film having an anisotropic region and an isotropic region]
A retardation film comprising a first retardation film and a second retardation film having an anisotropic region and an isotropic region as evaluated in the first embodiment and the second embodiment is, for example, the second A retardation film may be manufactured, and the manufactured second retardation film may be bonded to the first retardation film.

As the first retardation film, for example, a stretched film formed of a resin may be used.
The resin forming the stretched film usually contains a polymer (polymer). Examples of polymers contained in these resins include chain olefin polymers, cycloolefin polymers, polycarbonate, polyester, polysulfone, polyethersulfone, polystyrene, polyvinyl alcohol, cellulose acetate polymer, polyvinyl chloride, polymethacrylate, and the like. It is done. Among these, a chain olefin polymer and a cycloolefin polymer are preferable, and a cycloolefin polymer is particularly preferable from the viewpoint of transparency, low hygroscopicity, dimensional stability, lightness, and the like.

  In addition, the resin may include a single type of polymer, or may include a combination of two or more types of polymers in any ratio. Moreover, unless the effect of this invention is impaired remarkably, you may include arbitrary compounding agents in resin. Specific examples of suitable resins include “Zeonor 1420” manufactured by Zeon Corporation.

  Furthermore, as the first retardation film, a single layer structure film or a multilayer structure film may be used.

  Examples of suitable first retardation films include commercially available obliquely stretched films and long transversely stretched films such as those manufactured by Nippon Zeon Co., Ltd., product names “obliquely stretched ZEONOR film” and “transversely stretched ZEONOR film”. Can be mentioned.

  As the second retardation film, for example, a film produced on a substrate using a material that can exhibit a liquid crystal phase and can be cured by irradiation with energy rays such as ultraviolet rays (UV) may be used. Hereinafter, such a material may be referred to as a “liquid crystal layer forming composition”. In addition, an uncured layer or a cured layer of such a material may be referred to as a “liquid crystal resin layer” below.

  The second retardation film is obtained by, for example, applying a liquid crystal layer forming composition to a substrate to obtain an uncured liquid crystal resin layer, curing a part of the liquid crystal resin layer in a certain alignment state, You may manufacture by hardening one part in the orientation state (namely, the state which is not oriented) of an isotropic phase. Such a manufacturing method can be performed using a long base film as a base material, and is rubbed in the transport direction so that the base film is parallel to the rubbing direction (the slow axis is the transport direction). The composition for forming a liquid crystal layer is oriented in parallel, and therefore the second retardation film can be produced as a long film, which is excellent in terms of production efficiency.

In particular,
i. Producing a mask layer having a light-shielding part capable of shielding energy rays and a light-transmitting part capable of transmitting the energy rays on one surface of the base film;
ii. A step of providing an uncured liquid crystal resin layer on the surface of the base film opposite to the mask layer;
iii. A first region of the liquid crystal resin layer is cured by irradiating an energy ray having a wavelength that is shielded from light by the light shielding part but is transmitted through the light transmitting part from the mask layer side of the base film. Curing process,
iv. Changing the alignment state in the uncured region of the liquid crystal resin layer;
v. You may manufacture by the manufacturing method which has a 2nd hardening process of irradiating an energy ray from the opposite side to the said mask layer of the said base film, and hardening | curing the area | region of the said liquid crystal resin layer.

  The second retardation film produced as described above is usually used after peeling off the base film and the mask layer. However, you may use a base film and a mask layer suitably, without peeling.

  In the method for producing the second retardation film, the material of the base film is a material that can transmit energy rays such as ultraviolet rays to such an extent that the liquid crystal resin layer can be cured in the step of curing the uncured liquid crystal resin layer. Can be used. Usually, a material having a thickness of 1 mm and a total light transmittance (based on JIS K7361-1997, using a turbidimeter (made by Nippon Denshoku Industries Co., Ltd., NDH-300A)) of 80% or more is suitable. is there.

  If the example of the material of a base film is given, resin etc. which were mentioned as a material of a 1st phase difference film will be mentioned. One of these materials may be used alone, or two or more of these materials may be used in combination at any ratio.

  The thickness of the base film is preferably 30 μm or more, more preferably 60 μm or more, preferably 300 μm or less, more preferably 200 μm or less, from the viewpoints of handling properties at the time of manufacture, material cost, thickness reduction and weight reduction. is there.

  The base film may be a non-stretched unstretched film or a stretched stretched film. Further, it may be an isotropic film or an anisotropic film.

  The base film may be a single-layer film composed of only one layer, or may be a multilayer film composed of two or more layers. Usually, from the viewpoint of productivity and cost, a film having a single layer structure is used.

  The base film may have a surface treated on one side or both sides. By performing the surface treatment, adhesion with other layers directly formed on the surface of the base film can be improved. Examples of the surface treatment include energy ray irradiation treatment and chemical treatment. Moreover, you may have an orientation film in the surface which apply | coats the liquid crystal layer forming composition of a base film.

  As a material for the mask layer, a mask composition which can shield energy rays, particularly ultraviolet rays, and can easily form a pattern may be appropriately selected and used.

  Usually, a resin is used as the mask composition. The resin is, for example, selected from the group consisting of acrylic resin, urethane resin, polyamide resin, cellulose ester resin, polyester resin, polyimide resin, polyamideimide resin, urethane acrylate cured resin, epoxy acrylate cured resin, and polyester acrylate cured resin. At least one kind of resin is preferred. By including these resins, it is possible to hold a material that blocks ultraviolet rays even in a high-temperature environment and to produce a stable light-blocking portion. The above resins may be used alone or in combination of two or more at any ratio.

  The glass transition temperature of the resin contained in the mask composition is usually 80 ° C. or higher, preferably 100 ° C. or higher, and is usually 400 ° C. or lower, preferably 350 ° C. or lower. By setting the glass transition temperature to 80 ° C. or higher, the heat resistance of the mask layer can be increased. For example, the mask layer can be prevented from being deformed when the liquid crystal resin layer is heated. Further, by setting the glass transition temperature to 400 ° C. or less, the solubility of the resin can be improved and the mask composition can be easily printed. When the glass transition temperature of the resin changes between the state before printing and the state after forming the mask layer, the glass transition temperature is preferably within the above range in the state after forming the mask layer.

  The mask composition preferably contains an ultraviolet absorber. Thereby, the light shielding part of the mask layer contains the ultraviolet absorber, and the ultraviolet light can be stably shielded in the light shielding part. As the UV absorber, at least one UV absorber selected from the group consisting of benzophenone UV absorbers, benzotriazole UV absorbers and triazine UV absorbers is preferably used. One type of ultraviolet absorber may be used alone, or two or more types may be used in combination at any ratio. The amount of the ultraviolet absorber used is usually 5 parts by weight or more, preferably 8 parts by weight or more, more preferably 10 parts by weight or more, and usually 20 parts by weight with respect to 100 parts by weight of the monomer, oligomer and polymer in the mask layer. Parts or less, preferably 18 parts by weight or less, more preferably 15 parts by weight or less.

  The mask composition may further contain a colorant, metal particles, a solvent, a photopolymerization initiator, a crosslinking agent, and other components.

  As a method of forming a mask layer using a mask composition, a gravure printing method, a screen printing method, an offset printing method, a rotary screen printing method, a gravure offset printing method, an ink jet printing method, or a printing method that is a combination thereof Can be preferably mentioned. The light transmitting part and the light shielding part may be provided, for example, by forming a thin layer and a thick layer of the mask layer.

  As the liquid crystal layer forming composition, a composition containing a liquid crystal compound can be used. As said liquid crystal compound, the liquid crystal compound which has a polymeric group, a side chain type liquid crystal polymer compound, etc. are mentioned, for example. Examples of the liquid crystal compound having a polymerizable group include JP-A-11-513360, JP-A-2002-030042, JP-A-2004-204190, JP-A-2005-263789, and JP-A-2007-119415. Examples thereof include rod-like liquid crystal compounds having a polymerizable group described in JP-A No. 2007-186430. Moreover, as a side chain type liquid crystal polymer compound, the side chain type liquid crystal polymer compound etc. which are described in Unexamined-Japanese-Patent No. 2003-177242 etc. are mentioned, for example. Further, examples of preferable liquid crystal compounds include “LC242” manufactured by BASF and the like. A liquid crystal compound may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

  The refractive index anisotropy Δn of the liquid crystal compound in the composition for forming a liquid crystal layer is preferably 0.05 or more, more preferably 0.10 or more, preferably 0.30 or less, more preferably 0 at a wavelength of 546 nm. .25 or less. If the refractive index anisotropy Δn is less than 0.05, in order to obtain a desired optical function, the thickness of the liquid crystal resin layer may be increased, and the alignment uniformity may be lowered. is there. If the refractive index anisotropy Δn is greater than 0.30, the thickness of the liquid crystal resin layer becomes thin in order to obtain a desired optical function, which is disadvantageous for the thickness accuracy. Further, when Δn is larger than 0.30, the absorption edge on the long wavelength side of the ultraviolet absorption spectrum of the liquid crystal resin layer may reach the visible range. It can be used as long as the performance is not adversely affected. When the composition for forming a liquid crystal layer contains only one kind of liquid crystal compound, the refractive index anisotropy of the liquid crystal compound is directly used as the refractive index anisotropy of the liquid crystal compound in the composition for forming a liquid crystal layer. Moreover, when the composition for forming a liquid crystal layer contains two or more liquid crystal compounds, the weighted average value obtained from the value of refractive index anisotropy Δn of each liquid crystal compound and the content ratio of each liquid crystal compound, The refractive index anisotropy of the liquid crystal compound in the liquid crystal layer forming composition is used. The value of the refractive index anisotropy Δn can be measured by the Senarmon method.

  Furthermore, the composition for forming a liquid crystal layer may contain other components in addition to the liquid crystal compound in order to impart proper physical properties to the production method and final performance. Examples of other components include organic solvents, surfactants, chiral agents, polymerization initiators, ultraviolet absorbers, crosslinking agents, antioxidants, and the like. These components may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios.

Preferable examples of the organic solvent include ketones, alkyl halides, amides, sulfoxides, heterocyclic compounds, hydrocarbons, esters, ethers, and the like. Among these, cyclic ketones and cyclic ethers are preferable because they easily dissolve the liquid crystal compound. Examples of the cyclic ketone solvent include cyclopropanone, cyclopentanone, cyclohexanone, and the like, among which cyclopentanone is preferable. Examples of the cyclic ether solvent include tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, etc. Among them, 1,3-dioxolane is preferable. One type of solvent may be used alone, or two or more types may be used in combination at any ratio, and the solvent is optimized from the viewpoint of compatibility, viscosity, and surface tension as a liquid crystal layer forming composition. It is preferable.
The content ratio of the organic solvent is usually 30% by weight or more and 95% by weight or less as a ratio with respect to the total solid content other than the organic solvent.

  As the surfactant, it is preferable to select and use one that does not inhibit the orientation. Examples of preferred surfactants include nonionic surfactants containing a siloxane and a fluorinated alkyl group in the hydrophobic group portion. Of these, oligomers having two or more hydrophobic group moieties in one molecule are particularly suitable. Examples of these surfactants are OMNOVA PolyFox's PF-151N, PF-636, PF-6320, PF-656, PF-6520, PF-3320, PF-651, PF-652; FTX-209F, FTX-208G, FTX-204D of Neos, Inc. FC-430, FC-4430, FC-4432; KH-40 of Surflon, Seimi Chemical Co., Ltd. One type of surfactant may be used, or two or more types may be used in combination at any ratio.

  The blending ratio of the surfactant is preferably such that the concentration of the surfactant in the liquid crystal resin layer obtained by curing the liquid crystal layer forming composition is 0.05% by weight or more and 3% by weight or less. If the blending ratio of the surfactant is less than 0.05% by weight, the alignment regulating force at the air interface is lowered and alignment defects may occur. On the other hand, when the amount is more than 3% by weight, an excessive surfactant may enter between the liquid crystal compound molecules to reduce the alignment uniformity.

  The chiral agent may be a polymerizable compound or a non-polymerizable compound. As the chiral agent, a compound having a chiral carbon atom in the molecule and not disturbing the alignment of the liquid crystal compound is usually used. When an example of the chiral agent is given, “LC756” manufactured by BASF and the like may be mentioned as the polymerizable chiral agent. Moreover, for example, those described in JP-A-11-193287, JP-A-2003-13787 and the like can be mentioned. One type of chiral agent may be used, or two or more types may be used in combination at any ratio. A chiral agent is usually used in combination with a polymerizable liquid crystal compound when forming a region having a twisted nematic phase.

  As the polymerization initiator, for example, a thermal polymerization initiator may be used, but usually a photopolymerization initiator is used. As a photoinitiator, the compound which generate | occur | produces a radical or an acid with an ultraviolet-ray or visible light can be used, for example. Examples of photopolymerization initiators include benzoin, benzylmethyl ketal, benzophenone, biacetyl, acetophenone, Michler's ketone, benzyl, benzylisobutyl ether, tetramethylthiuram mono (di) sulfide, 2,2-azobisisobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, benzoyl peroxide, di-tert-butyl peroxide, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one 1- (4-Isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-diethylthioxanthone, methylbenzoyl formate 2,2-diethoxyacetophenone, β-ionone, β-bromostyrene, diazoaminobenzene, α-amylcinnacaldehyde, p-dimethylaminoacetophenone, p-dimethylaminopropiophenone, 2-chlorobenzophenone, pp′- Dichlorobenzophenone, pp'-bisdiethylaminobenzophenone, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-propyl ether, benzoin n-butyl ether, diphenyl sulfide, bis (2,6-methoxybenzoyl) -2,4,4-trimethyl- Pentylphosphine oxide, 2,4,6-trimethylbenzoyldiphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, Anthracene benzophenone, α-chloroanthraquinone, diphenyl disulfide, hexachlorobutadiene, pentachlorobutadiene, octachlorobutene, 1-chloromethylnaphthalene, 1,2-octanedione, 1- [4- (phenylthio) -2- (o- Benzoyloxime)] and 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] ethanone 1- (o-acetyloxime), (4-methylphenyl) [4- (2-Methylpropyl) phenyl] iodonium hexafluoroph Sufeto, 3-methyl-2-butynyl tetramethyl hexafluoroantimonate, diphenyl - (p-phenylthiophenyl) sulfonium hexafluoroantimonate, and the like. One type of polymerization initiator may be used, or two or more types may be used in combination at any ratio. Furthermore, you may adjust photocuring agents, such as a tertiary amine compound, or a polymerization accelerator, for example to a liquid crystal layer forming composition as needed, and may adjust the sclerosis | hardenability of the composition for liquid crystal layer forming. In order to improve the photopolymerization efficiency, it is preferable to appropriately select the average molar extinction coefficient of the liquid crystal compound and the photopolymerization initiator.

  Examples of the ultraviolet absorber include 2,2,6,6-tetramethyl-4-piperidylbenzoate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, and bis (1,2,2). , 6,6-pentamethyl-4-piperidyl) -2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butyl malonate, 4- (3- (3,5-di) -T-butyl-4-hydroxyphenyl) propionyloxy) -1- (2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -2,2,6 Hindered amine ultraviolet absorbers such as 6-tetramethylpiperidine; 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (3-t-butyl-2-hydroxy-5-methylphenyl) 5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-amyl-2-hydroxyphenyl) benzo Benzotriazole ultraviolet absorbers such as triazole; 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, hexadecyl-3,5-di-t-butyl-4- Examples thereof include benzoate ultraviolet absorbers such as hydroxybenzoate; benzophenone ultraviolet absorbers, and acrylonitrile. These ultraviolet absorbers may be used alone or in combination of two or more at an arbitrary ratio in order to impart desired light resistance.

  The blending ratio of the ultraviolet absorber is usually 0.001 part by weight or more, preferably 0.01 part by weight or more, and usually 5 parts by weight or less, preferably 1 part by weight or less with respect to 100 parts by weight of the liquid crystal compound. . When the blending ratio of the UV absorber is less than 0.001 part by weight, the UV absorbing ability may be insufficient, and the desired light resistance may not be obtained. When the composition is cured with active energy rays such as ultraviolet rays, the curing becomes insufficient, and the mechanical strength of the liquid crystal resin layer may be lowered or the heat resistance may be lowered.

  The composition for forming a liquid crystal layer may contain a crosslinking agent according to the desired mechanical strength. Examples of cross-linking agents include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2- (2-vinyloxyethoxy) Polyfunctional acrylate compounds such as ethyl acrylate; Epoxy compounds such as glycidyl (meth) acrylate, ethylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol tetraglycidyl ether; 2,2-bishydroxymethylbutanol-tris [3- ( 1-aziridinyl) propionate], 4,4-bis (ethyleneiminocarbonylamino) diphenylmethane, trimethylolpropane-tri-β-aziridinylpropionate Aziridine compounds such as nates; Isocyanurate type isocyanates derived from hexamethylene diisocyanate, hexamethylene diisocyanate, isocyanurate type isocyanates, biuret type isocyanates, adduct type isocyanates; polyoxazoline compounds having oxazoline groups in the side chain; N- (2-aminoethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, N- (1 , 3-dimethylbutylidene) -3- (triethoxysilyl) -1-propanamine and the like alkoxysilane compounds; A crosslinking agent may be used individually by 1 type, and may be used combining two or more types by arbitrary ratios. Further, the liquid crystal layer forming composition may contain a known catalyst according to the reactivity of the cross-linking agent to improve the productivity in addition to improving the film strength and durability.

  The blending ratio of the crosslinking agent is preferably such that the concentration of the crosslinking agent in the cured liquid crystal resin layer is 0.1 wt% or more and 20 wt% or less. If the blending ratio of the crosslinking agent is less than 0.1% by weight, the effect of improving the crosslinking density may not be obtained. Conversely, if it exceeds 20% by weight, the stability of the liquid crystal resin layer after curing may be lowered. There is.

  Antioxidants include, for example, phenolic antioxidants such as tetrakis (methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate) methane, phosphorus antioxidants, and thioether oxidations. Examples include inhibitors. An antioxidant may be used individually by 1 type and may be used combining two or more types by arbitrary ratios. The blending amount of the antioxidant can be within a range in which the transparency and adhesive strength of the adhesive layer are not lowered.

  When providing an uncured liquid crystal resin layer, a coating method is usually used. Examples of the method for applying the liquid crystal layer forming composition include a reverse gravure coating method, a direct gravure coating method, a die coating method, and a bar coating method. By applying the composition for forming a liquid crystal layer to the surface of the base film, an uncured liquid crystal resin layer is formed.

  The composition for forming a liquid crystal layer may be applied directly to the surface of the base film, but may be applied indirectly to the surface of the base film via, for example, an alignment film. If the alignment film is used, the liquid crystal compound can be easily aligned in the liquid crystal resin layer.

  The alignment film may be formed using, for example, cellulose, silane coupling agent, polyimide, polyamide, polyvinyl alcohol, epoxy acrylate, silanol oligomer, polyacrylonitrile, phenol resin, polyoxazole, cyclized polyisoprene, or the like. One of these may be used alone, or two or more of these may be used in combination at any ratio.

  The thickness of the alignment film may be any thickness that provides the desired alignment uniformity of the liquid crystal resin layer, and is preferably 0.001 μm or more, more preferably 0.01 μm or more, preferably 5 μm or less, more preferably 2 μm. It is as follows. Further, for example, a photo-alignment film as shown in JP-A-6-289374, JP-A-2002-507872, JP-A-4022985, JP-A-4267080, JP-A-46477782, US Pat. No. 5,389,698, and the like. Alternatively, the liquid crystal compound may be aligned by a method using polarized UV.

Further, the liquid crystal compound may be aligned by means other than the alignment film described above. For example, an alignment treatment may be performed such that the surface of the base film is directly rubbed without using an alignment film. Usually, the conveyance direction of a base film and a rubbing direction become parallel.
The processing steps such as the formation of the alignment film and the rubbing of the surface of the base film may be performed before, during or after the mask layer forming step, but the liquid crystal resin in an uncured state It is preferable to carry out before the step of providing the layer.

  In the method for producing the second retardation film, the orientation for aligning the liquid crystal compound of the liquid crystal resin layer after performing the step of providing an uncured liquid crystal resin layer as necessary prior to the first curing step. You may perform a process. As a specific operation in the alignment step, for example, an operation of heating an uncured liquid crystal resin layer to a predetermined temperature in an oven can be exemplified.

  The temperature at which the liquid crystal resin layer is heated in the alignment step is usually 40 ° C. or higher, preferably 50 ° C. or higher, and is usually 200 ° C. or lower, preferably 140 ° C. or lower. The treatment time in the heat treatment is usually 1 second or longer, preferably 5 seconds or longer, usually 3 minutes or shorter, preferably 120 seconds or shorter. Thereby, the liquid crystal compound in the liquid crystal resin layer can be aligned. Moreover, when a solvent is contained in the composition for forming a liquid crystal layer, the solvent is usually dried by the heating, and thus the solvent is removed from the liquid crystal resin layer. Therefore, when the alignment process is performed, a drying process for drying the liquid crystal resin layer usually proceeds simultaneously. Usually, the alignment axis of the liquid crystal resin layer is parallel to the rubbing direction, and the alignment axis is the slow axis.

After performing an alignment process as needed, the 1st hardening process of hardening a one part area | region of a liquid crystal resin layer is performed. The first curing step is usually performed by ultraviolet irradiation. The ultraviolet irradiation time, the irradiation amount, and other conditions can be appropriately set according to the composition of the liquid crystal layer forming composition, the thickness of the liquid crystal resin layer, and the like. The irradiation time is usually in the range of 0.01 seconds to 3 minutes, and the irradiation amount is usually in the range of 0.01 mJ / cm ² to 50 mJ / cm ² . Further, the irradiation of ultraviolet rays may be performed in an inert gas such as nitrogen and argon, or may be performed in the air.

  After the first curing step, a step of changing the alignment state in the uncured region of the liquid crystal resin layer is performed. In this step, as a method of changing the alignment state, for example, the liquid crystal resin layer may be heated to a clearing point (NI point) or more of the liquid crystal layer forming composition by a heater. Thereby, since the orientation of the liquid crystal compound molecules becomes random, the uncured region of the liquid crystal resin layer has an isotropic phase.

After changing the alignment state in the uncured region of the liquid crystal resin layer, the second curing step is performed. You may perform a 2nd hardening process by irradiation of an ultraviolet-ray. The ultraviolet irradiation time, the irradiation amount, and the like can be appropriately set according to the composition of the liquid crystal layer forming composition and the thickness of the liquid crystal resin layer, but the irradiation amount is usually from 50 mJ / cm ² to 10,000 mJ / cm ^2. Range. Further, the irradiation of ultraviolet rays may be performed in an inert gas such as nitrogen and argon, or may be performed in the air. During irradiation, if necessary, heating with a heater may be continued to perform irradiation while maintaining the isotropic phase of the uncured liquid crystal resin layer.

Furthermore, as another manufacturing method, the second retardation film is
i. A step of providing an uncured liquid crystal resin layer on one surface of the base film;
ii. The liquid crystal resin is irradiated with energy rays on a surface opposite to the surface on which the liquid crystal resin layer of the base film is provided through a glass mask in which a light transmitting portion and a light shielding portion of a stripe pattern are provided on the glass. A first curing step for curing a partial region of the layer;
iii. Changing the alignment state in the uncured region of the liquid crystal resin layer;
iv. You may manufacture with the manufacturing method which has a 2nd hardening process of irradiating the surface which provided the liquid crystal resin layer of the said base film with an energy ray, and hardening | curing the area | region of the said liquid crystal resin layer. In this manufacturing method, the same operation as the manufacturing method described above may be performed under the same conditions as the manufacturing method described above.

Moreover, as a 1st hardening process, you may use the method shown in Unexamined-Japanese-Patent No. 4-299332. The glass mask may be, for example, one obtained by performing chromium sputtering on the glass surface, further applying a photoresist, exposing the photoresist in a stripe shape, exposing the photoresist, washing, and etching chromium. Alternatively, for example, a PET film coated with a photosensitive emulsion may be laser-drawn in a stripe shape, washed, and the PET film bonded onto a glass via an adhesive layer.
Furthermore, in each manufacturing method mentioned above, as long as a 2nd phase difference film is obtained, the order of each process is arbitrary.

  According to the manufacturing method mentioned above, the 2nd phase difference film which has a pattern which copied the mask pattern of the mask layer or glass mask formed of a light-shielding part and a translucent part with high precision can be manufactured. Furthermore, in the second retardation film obtained by the method, there is material continuity between the anisotropic region and the isotropic region. Therefore, it is optically advantageous in that it does not cause reflection and scattering due to the gap between regions, and it is advantageous in terms of mechanical strength in that it does not cause breakage starting from the gap between regions.

  The thickness of the liquid crystal resin layer as the second retardation film depends on the value of the refractive index anisotropy Δn of the liquid crystal compound in the composition for forming a liquid crystal layer. Can be set to an appropriate thickness so that Usually, the thickness of the liquid crystal resin layer is in the range of 0.5 μm to 50 μm.

  By laminating the second retardation film thus obtained to the first retardation film, a retardation film having the first retardation film and the second retardation film is obtained. Under the present circumstances, you may use an adhesive agent for bonding as needed.

[6-5. Retardation film having anisotropic regions having different slow axis directions]
As the retardation film having a plurality of anisotropic regions with different slow axis directions as evaluated in the third embodiment and the fourth embodiment, for example, those manufactured by the method described below may be used. .
That is, this manufacturing method
i. A step of forming a layer of a photo-alignment material (hereinafter sometimes referred to as “photo-alignment material layer”) on the surface of the base film;
ii. Irradiating polarized light to a partial region of the photo-alignment material layer;
iii. Irradiating the entire photo-alignment material layer with polarized light having a polarization direction different from that of the polarized light by 90 ° ± 3 ° to obtain an alignment film;
iv. Forming a liquid crystal layer-forming composition layer (that is, an uncured liquid crystal resin layer) containing a liquid crystal compound and curable by irradiation with active energy rays on the surface of the alignment film;
v. Irradiating the liquid crystal resin layer with active energy rays to cure the liquid crystal resin layer.

The retardation film produced as described above is usually used after the base film is peeled off. However, you may use a base film, without peeling suitably.
As a base film, you may use the film similar to what was mentioned above in description of retardation film provided with a 1st phase difference film and a 2nd phase difference film.

  The photo-alignment material is a material that is irreversibly aligned when irradiated with polarized light. Examples of such photo-alignment materials include PPN materials used in the PPN layer described in Japanese Patent No. 4267080, LPP / LCP mixtures described in Japanese Patent No. 46477782, PPN materials described in No. 2543666, and the like. Can be mentioned. In addition, these may be used individually by 1 type and may be used combining two or more types by arbitrary ratios.

The surface of the base film is subjected to corona discharge treatment (output 0.2 kW, base film wetting index 56 dyne / cm ² ), and a photo-alignment material layer is formed by applying, for example, a photo-alignment material on the treated surface. The thickness of the photo-alignment material layer may be any thickness as long as the desired alignment uniformity of the liquid crystal resin layer is obtained, and is preferably 0.001 μm or more, more preferably 0.01 μm or more, and preferably 5 μm or less. Is 2 μm or less.

  After forming the photo-alignment material layer, a step of irradiating polarized light to a partial region of the photo-alignment material layer (first polarization irradiation step) is performed. In the region irradiated with polarized light, the photo-alignment material is irreversibly aligned in the photo-alignment material layer, and is fixed while maintaining the alignment state.

  In the first polarized light irradiation step, the light alignment material layer is usually irradiated with polarized light through a mask. In this case, as the mask, a mask having a strip-shaped light shielding portion and a light transmitting portion that extend in parallel with a certain direction is usually used. Thereby, polarized light can be irradiated to the strip | belt-shaped area | region extended in parallel with a certain direction of a photo-alignment material layer.

  As a mask, you may use the mask layer formed in the opposite side to the photo-alignment material layer of a base film, for example. The mask layer may be formed in the same manner as described above in the description of the retardation film including the first retardation film and the second retardation film.

Further, as a mask, for example, a glass mask in which chromium is sputtered on the glass surface, further coated with a photoresist, exposed to stripes to expose the photoresist, washed, and etched with chromium may be used. .
Alternatively, for example, a mask may be used in which a PET film coated with a photosensitive emulsion is laser-drawn in stripes, washed, and the PET film is bonded onto glass via an adhesive layer.

  In the first polarized light irradiation step, as the polarized light, light having a wavelength capable of orienting the photo-alignment material, which is shielded by the light shielding part of the mask but transmitted through the light transmitting part, is used. As such polarized light, ultraviolet rays are usually used. The ultraviolet irradiation time, the irradiation amount, and other conditions can be appropriately set according to the composition of the photo-alignment material and the thickness of the photo-alignment material layer. Further, the irradiation of polarized light may be performed in an inert gas such as nitrogen and argon, or may be performed in the air.

  After the first polarized light irradiation step, a second polarized light irradiation step of irradiating the entire photo-alignment material layer with polarized light having a polarization direction different from the polarized light by 90 ° ± 3 ° is performed. Thereby, in the area | region where the polarized light was not irradiated in the 1st polarized light irradiation process, photo-alignment material orientates irreversibly and is fixed with the alignment state maintained. In addition, since the polarization direction of the polarized light irradiated in the first polarized light irradiation step and the polarized light irradiated in the second polarized light irradiation step are different by 90 ° ± 3 °, in the second polarized light irradiation step in the photo-alignment material layer The orientation direction of the oriented region differs from the orientation direction of the region oriented in the first polarized light irradiation step by 90 ° ± 3 °.

The second polarized light irradiation step may be performed, for example, by irradiating polarized light without using a mask. Irradiation time of polarization, such as the dose is be appropriately set depending on the thickness of the composition and the optical alignment material layer of the optical alignment material, ranges irradiation amount usually 50 mJ / cm ² of 10,000 / cm ² It is. Further, the irradiation of polarized light may be performed in an inert gas such as nitrogen and argon, or may be performed in the air.

  By the manufacturing method described above, an alignment film composed of a photo-alignment material layer is obtained on the surface of the base film. In this alignment film, two types of regions with different alignment directions of 90 ° ± 3 ° form a pattern that accurately copies the mask pattern of the mask formed by the light shielding portion and the light transmitting portion. In this example, two types of regions with different orientation directions of 90 ° ± 3 ° are alternately arranged in a strip shape extending in parallel to a certain direction, thereby forming a stripe shape as a whole. A pattern is formed.

  After forming the alignment film on the base film, a liquid crystal resin layer is formed on the surface of the alignment film. As the composition for forming a liquid crystal layer, for example, the same composition for forming a liquid crystal layer as described above in the description of the retardation film including the first retardation film and the second retardation film may be used.

  When providing an uncured liquid crystal resin layer, a coating method is usually used. As a coating method of the composition for forming a liquid crystal layer, for example, the same method as described above in the description of the retardation film including the first retardation film and the second retardation film may be used. By applying the composition for forming a liquid crystal layer to the surface of the base film, an uncured liquid crystal resin layer is formed.

  After performing the step of forming an uncured liquid crystal resin layer, an alignment step of aligning the liquid crystal compound contained in the liquid crystal resin layer may be performed as necessary. By performing the alignment step, the liquid crystal compound is aligned in a direction corresponding to the alignment direction of each region of the alignment film. As a specific operation in the alignment step, for example, the same operation as described above in the description of the retardation film including the first retardation film and the second retardation film may be performed.

  After performing an alignment process as needed, the process (curing process) of hardening an uncured liquid crystal resin layer is performed. In each region of the liquid crystal resin layer to be cured, a polymerization reaction proceeds in the composition for forming a liquid crystal layer, and the liquid crystal compound is fixed while maintaining the alignment state. Thereby, the retardation film which consists of a liquid-crystal resin layer is formed in the surface of a base film through an orientation film.

The curing step is usually performed by ultraviolet irradiation. The ultraviolet irradiation time, the irradiation amount, and the like can be appropriately set according to the composition of the liquid crystal layer forming composition and the thickness of the liquid crystal resin layer, but the irradiation amount is usually from 50 mJ / cm ² to 10,000 mJ / cm ^2. Range. Further, the irradiation of ultraviolet rays may be performed in an inert gas such as nitrogen and argon, or may be performed in the air.

  In this retardation film, two types of regions having different slow axis directions form a pattern that accurately copies the pattern of regions having different orientation directions formed on the alignment film. Usually, the alignment direction in each region of the alignment film and the slow axis direction of each region of the retardation film formed on the surface thereof are parallel or perpendicular. Therefore, when regions having different orientation directions of 90 ° ± 3 ° are formed in the alignment film as in this example, the slow axis direction of each region in the retardation film is vertical.

  Furthermore, in the retardation film obtained by the manufacturing method, there is material continuity between anisotropic regions having different slow axis directions. Therefore, the above-described manufacturing method is optically advantageous in that it does not cause reflection and scattering due to gaps between different types of anisotropic regions, and also includes breakage starting from the gaps between anisotropic regions. This is also advantageous in terms of mechanical strength in that it does not cause the problem.

In the manufacturing method of said retardation film, you may make it perform processes other than the process mentioned above as needed.
Moreover, as long as a desired retardation film is obtained, the order of each process is arbitrary.

  The thickness of the liquid crystal resin layer as the retardation film is such that a desired retardation Re can be obtained in each region of the retardation film according to the refractive index anisotropy Δn of the liquid crystal compound in the liquid crystal layer forming composition. Can be set to an appropriate thickness. Usually, the thickness of the liquid crystal resin layer is in the range of 0.5 μm to 50 μm.

[7. Application]
The retardation film evaluated by the evaluation method described above has a function of converting a polarization state before passing through it into another different polarization state by optical characteristics such as the magnitude of the retardation and the axial angle of the optical axis. Therefore, it is used for optical elements such as liquid crystal display devices and the like for preventing forgery of articles. For example, it may be used for a passive stereoscopic image display device, and is particularly suitable for a stereoscopic image display device including a liquid crystal display device.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. However, the present invention is not limited to the examples described below, and does not depart from the scope of the claims of the present invention and the equivalents thereof. It may be carried out by arbitrarily changing in. In the following description, “%” and “parts” representing amounts are based on weight unless otherwise specified. In the following description, the measurement wavelength of the phase difference Re is 550 nm unless otherwise specified. Further, the operations described below were performed under normal temperature and normal pressure conditions unless otherwise specified.

[1. Example 1]
[1.1 Preparation of retardation film to be evaluated]
(Preparation of liquid crystal composition)
75 parts by weight of a polymerizable liquid crystal compound (manufactured by BASF, product name “LC242”), 20 parts by weight of the following compound 1, and 5 parts by weight of a crosslinking agent (manufactured by Shin-Nakamura Chemical Co., Ltd., trimethylolpropane triacrylate) 3 parts by weight of a polymerization initiator (manufactured by BASF, product name “Irg 379”), 0.1 part by weight of a surfactant MegaFac-F477 (made by DIC) containing fluorine, and 200 of methyl ethyl ketone A composition for forming a liquid crystal layer was prepared by mixing with parts by weight.

(Preparation of second retardation film)
A long polyethylene terephthalate film (“PET film A4100” manufactured by Toyobo Co., Ltd .; thickness 100 μm) having an in-plane refractive index isotropic and having an in-plane refractive index was prepared as a base film. Attach this base film to the feeding section of the film transport device, apply rubbing while transporting the base film, and use the die coater for the liquid crystal layer forming composition prepared above on the surface subjected to rubbing And applied. Thus, an uncured liquid crystal composition layer was formed as a coating film on one surface of the base film.

The liquid crystal composition layer was aligned at 40 ° C. for 2 minutes to align the polymerizable liquid crystal compound in the liquid crystal composition layer.
Then, the weak ultraviolet-ray of 15 mJ / cm < ² > was irradiated with respect to the liquid crystal composition layer through the glass mask from the opposite side to which the liquid crystal composition layer of the base film was formed. As the glass mask, a light transmitting portion and a light shielding portion extending in a predetermined direction were formed in a stripe shape in parallel with each other. The width of the light transmitting part of the glass mask was 306.4 μm, and the width of the light shielding part was 316.0 μm. The liquid crystal composition layer remains uncured because it was not exposed at the position corresponding to the light shielding part of the glass mask, but the liquid crystal composition layer was cured because it was exposed at the position corresponding to the light transmitting part of the glass mask. did. This forms an anisotropic region (λ / 2 region; phase difference Re = 241 nm at a measurement wavelength of 543 nm) having an in-plane retardation Re that can function as a half-wave plate in the exposed portion of the liquid crystal composition layer. did.

Next, the liquid crystal composition layer is heated at 90 ° C. for 10 seconds to change the liquid crystal phase of the uncured portion of the liquid crystal composition layer (the portion corresponding to the light-shielding portion of the glass mask) to the isotropic phase. It was.
While maintaining this state, the liquid crystal composition layer was irradiated with ultraviolet rays with an integrated light amount of 300 mJ / cm ² from the liquid crystal composition layer side of the base film in a nitrogen atmosphere to remove the uncured portion of the liquid crystal composition layer. Cured. As a result, an isotropic region (Iso region; phase difference Re = 0.7 nm at a measurement wavelength of 543 nm) having a small in-plane retardation Re was formed in the liquid crystal composition layer.

  In this way, a liquid crystal composition layer having in the same plane an anisotropic region having an in-plane retardation Re that can function as a half-wave plate and an isotropic region having a small in-plane retardation Re. As a result, a second retardation film was obtained. The film including the second retardation film is a long film having a layer structure of (base film) − (second retardation film). The dry film thickness of the formed second retardation film was 4.7 μm. The in-plane retardation Re of the anisotropic region was 241 nm, and the slow axis in the in-plane direction made an angle of 0 ° with the longitudinal direction of the base film. On the other hand, the in-plane retardation Re of the isotropic region was 0.7 nm or less. The anisotropic region and the isotropic region were formed as band-like regions parallel to each other, and the width of each band was 311.1 μm.

(Attaching the first retardation film)
A first retardation film (manufactured by ZEON Corporation, product name “transversely stretched ZEONOR film”) was prepared. This first retardation film had an orientation angle of 90 ° with respect to the longitudinal direction, an in-plane retardation Re125 nm at a measurement wavelength of 543 nm, and a variation of in-plane retardation Re within the plane ± 10 nm or less.

  A curing agent (product name “E-AX”, manufactured by Soken Chemical Co., Ltd., product name “SK Dyne 2094”) is applied to an acrylic adhesive (product name “SK Dyne 2094”), and a curing agent is added to 100 parts by weight of the polymer in the acrylic adhesive Was added so as to have a ratio of 5 parts by weight. Hereinafter, this is abbreviated as “PSA” where appropriate.

  The first retardation film was bonded to the surface of the second retardation film of a long retardation film provided with the second retardation film via PSA. At this time, bonding was performed such that the slow axis of the first retardation film and the slow axis of the anisotropic region of the second retardation film were 90 °. This obtained the elongate retardation film which has the layer structure of (base film)-(2nd phase difference film)-(adhesion layer)-(1st phase difference film). The thickness of the adhesive layer was 25 μm.

[1.2. Preparation of evaluation system)
As shown in FIG. 3, a liquid crystal display device equipped with a CCFL as a light source 110 was installed on a gantry (not shown). This liquid crystal display device is manufactured by BENQ (model name: 27-inch LCD wide monitor, model number: M2700HD), and includes a polarizing film 121, a liquid crystal cell 122, and a polarizing film 123. The transmission axis A ₁₂₃ of the polarizing film 123 is 45 ° clockwise with respect to the in-plane reference direction X in the direction of observing the light source 110 with the microscope 150. Further, in the liquid crystal cell 122, a right-eye pixel region 124 and a left-eye pixel region 125 each made up of red, green, and blue pixels have a width of 311.4 μm and extend in the in-plane reference direction X. Is provided. A black matrix 126 having a width of 28.2 μm is provided between the pixel regions 124 and 125 of the liquid crystal cell 122.

  On top of the liquid crystal panel 120, a microscope 150 provided with a detachable circular polarizing filter 140 was installed at a predetermined interval. The microscope 150 is movable in parallel with the in-plane direction of the liquid crystal panel 120. Furthermore, a monitor (not shown) was connected to the microscope 150 so that an image observed by the microscope 150 was output to the monitor.

The previously prepared long retardation film was cut into a size corresponding to the liquid crystal panel 120. The cut-out retardation film 130 was bonded onto the liquid crystal panel 120 through water so that the slow axis A _{131 of} the first retardation film ₁₃₁ was 90 ° with respect to the in-plane reference direction X. The direction of the retardation film 130 was such that the first retardation film 131 was on the light source side and the second retardation film 132 was on the microscope side. The slow axis A ₁₃₃ of the anisotropic region 133 of the second retardation film 132 was parallel to the in-plane reference direction X.

The light source 110 is made to emit light, and the liquid crystal panel 120 is controlled so that the right-eye pixel region 124 of the liquid crystal cell 122 displays black that does not transmit light and the left-eye pixel region 125 displays white that transmits light. In this state, while viewing the retardation film 130 through a polarizing filter similar to the polarizing filter 140, the retardation film 130 was aligned so that a black display in which no light was observed was obtained. Thus, when viewed from the thickness direction, the pixel region 124 for the right eye of the liquid crystal cell 122 overlaps with the isotropic region 134 of the second retardation film 132, and the pixel region 125 for the left eye of the liquid crystal cell 122 is the second phase difference. The position was adjusted to overlap the anisotropic region 133 of the film 132.
Thus, the evaluation system shown in FIG. 3 was prepared.

[1.3. (Evaluation of linearity)
In a state where the light source 110 is illuminated, a grid 460 is displayed on the screen 120U of the liquid crystal panel 120 as shown in FIG. 17 using commercially available drawing application software. At this time, all of the red, green, and blue pixels transmit light so that the grid 460 is displayed in white. The grid 460 includes six rows of lines A to F parallel to the reference direction X in which the pixel regions 124 and 125 extend in the liquid crystal cell 122 and five columns of lines I to V perpendicular to the reference direction X. Yes. The interval between the lines A to F extending in the reference direction X was 160 pixels, and the interval between the lines I to V perpendicular to the reference direction X was 320 pixels.

In a state where such a grid 460 is displayed, the intersection of the grid 460 is observed with the microscope 150 without attaching the circular polarizing filter 140, and a reference line parallel to the reference direction X (the reference line 164 in FIG. 5). Reference) was set. Moreover, was observed with a microscope 150 wearing the circularly polarizing filter 140, the light source 110 has issued has identified the edges of the detected portions (see the edge of the FIG. 6 E _2). Thereafter, the amount of deviation Δd between the reference line and the edge of the portion where the light emitted from the light source 110 was detected was measured. The amount of deviation Δd was first measured in pixel units, and the unit was converted to μm by multiplying this by the width per pixel.
A similar operation was performed at all intersections of the grid 460. However, the reference line was set in the same manner at all intersections.

  The results of the deviation amount Δd at each intersection measured in this way were grouped for each of the lines A to F parallel to the reference direction X. Then, among the results of the grouped deviation amount Δd, the measurement result at the intersection on the line III perpendicular to the reference direction X is used as a reference (difference in deviation amount Δd = 0.0 μm), and the deviation amount Δd at each intersection. The differences were organized by group. The results are shown in FIG. In FIG. 18, the graph surrounded by a frame shows the results at the intersections on the lines A, B, C, D, E, and F of the grid 460 in order from the top. In addition, in FIG. 18, the results at the intersections on the lines I, II, III, IV, and V of the grid 460 are shown in order from the left in each of the graphs surrounded by the frame.

  As can be seen from FIG. 18, there is no significant difference in the deviation amount Δd between the intersections having different positions in the reference direction X in the results of any group. From this, it was found that the anisotropic flow region 133 and the isotropic region 134 are excellent in straightness.

[2. Example 2]
Using the result of the deviation amount Δd measured in Example 1, the following evaluation was performed.
First, the shift amounts Δd at all intersections of the grid 460 displayed on the liquid crystal panel 120 were grouped for each of the lines I to V perpendicular to the reference direction X (see FIG. 17). As a result of checking the grouped deviation amount Δd, the deviation amount Δd at the intersection on the uppermost line A in the figure among the lines A to F parallel to the reference direction X is the smallest in any group. It was found that the amount of deviation Δd is larger at the intersection on the lower line in the figure.

  Therefore, among the lines A to F parallel to the reference direction X, the deviation amount Δd at the intersection on the uppermost line A in the drawing and the deviation amount at the intersection on the lowest line F in the drawing. The amount of difference (difference) from Δd was calculated. The obtained difference amount was divided by 800 pixels (= 160 pixels × 5), which is the number of pixels from line A to line F, to calculate the difference amount per pixel. The results are shown in Table 1.

  The value per pixel thus obtained is the error that the total pitch of the pair of anisotropic regions 133 and isotropic regions 134 of the retardation film 130 has relative to the pitch of the pixel region of the liquid crystal panel 120 as a reference. Represents the size of. From Table 1, it can be seen that the total pitch error of the retardation film 130 manufactured in Example 1 is small.

[3. Example 3]
[3.1 Preparation of retardation film to be evaluated]
The retardation film was taken out from a stereoscopic image display device (model name: D2770P-PN; 27 inches) manufactured by LG Display. This retardation film has a stripe pattern in which two types of anisotropic regions having a quarter wavelength extend in parallel to the in-plane reference direction and are alternately provided. The slow axis directions of the two types of anisotropic regions of the retardation film were directions perpendicular to the direction parallel to the longitudinal direction. Further, the two types of anisotropic regions are different from each other in the slow axis direction by 90 °.

[3.2. Preparation of evaluation system)
As the retardation film 330, 3.1. The liquid crystal panel 120 and the one provided with the stereoscopic image display device from which the retardation film was taken out (“D2770P-PN” manufactured by LG Display, Inc.), Except for this, the evaluation system shown in FIG. 15 was prepared in the same manner as in Example 1.

[3.3. (Evaluation of linearity)
3.2. Using the evaluation system prepared in (1), the grid 460 was displayed on the screen 120U of the liquid crystal panel 120 in the same manner as in Example 1, and the amount of deviation Δd at these intersections was measured (see FIG. 17). Similarly to the first embodiment, the measured deviation amount Δd is grouped for each of the lines A to F parallel to the reference direction X, and the measurement result at the intersection on the line III perpendicular to the reference direction X is used as a reference (deviation). Difference in amount Δd = 0.0 μm), the difference in deviation amount Δd at each intersection was organized for each group. The results are shown in FIG. In FIG. 19, the graph surrounded by a frame shows the results at the intersections on the lines A, B, C, D, E, and F of the grid 460 in order from the top. Further, in FIG. 19, the results at the intersections on the lines I, II, III, IV, and V of the grid 460 are shown in order from the left in each of the graphs surrounded by a frame.

  As can be seen from FIG. 19, in any group result, the difference in the deviation amount Δd is larger than that in the first embodiment, but is not excessively large. From this, it was found that the anisotropic region of the retardation film prepared in Example 3 was excellent in straightness.

[4. Example 4]
Using the result of the shift amount Δd measured in Example 3, the total pitch was evaluated in the same manner as in Example 2.
That is, the shift amount Δd at all the intersections of the grid 460 displayed on the liquid crystal panel 120 was grouped for each of the lines I to V perpendicular to the reference direction X (see FIG. 17). In any group, among the lines A to F parallel to the reference direction X, the shift amount Δd at the intersection on the uppermost line A in the figure is the smallest, and the intersection on the lower line in the figure It was found that the deviation amount Δd was large.

  Therefore, among the lines A to F parallel to the reference direction X, the deviation amount Δd at the intersection on the uppermost line A in the drawing and the deviation amount at the intersection on the lowest line F in the drawing. The amount of difference (difference) from Δd was calculated. The obtained difference amount was divided by 800 pixels (= 160 pixels × 5), which is the number of pixels from line A to line F, to calculate the difference amount per pixel. The results are shown in Table 2.

  From Table 2, it can be seen that the total pitch error of the retardation film prepared in Example 3 is large.

[5. Example 5]
[5.1 Preparation of retardation film to be evaluated]
A retardation film was taken out from a stereoscopic image display device (model name: RDT233WX-3D; 23 inches) manufactured by Mitsubishi Electric Corporation. This retardation film has a stripe pattern in which two types of anisotropic regions having a quarter wavelength extend in parallel to the in-plane reference direction and are alternately provided. The slow axis directions of the two types of anisotropic regions of the retardation film were a direction forming an angle of + 45 ° with respect to the longitudinal direction and a direction forming an angle of −45 °. Further, the two types of anisotropic regions are different from each other in the slow axis direction by 90 °.

[5.2. Preparation of evaluation system)
As the retardation film 330, 5.1. The one prepared in was used. Further, as the liquid crystal panel 120, the one provided in the stereoscopic image display device ("RDT233WX-3D" manufactured by Mitsubishi Electric Corporation) from which the retardation film was taken out was used. In this liquid crystal panel 120, the transmission axis A ₁₂₁ of the light source side polarizing film 121 is perpendicular to the in-plane reference direction X, and the transmission axis A ₁₂₃ of the microscope side polarizing film ₁₂₃ is in-plane. Parallel to the reference direction X. An evaluation system was prepared in the same manner as in Example 1 except for the above items.

[5.3. (Evaluation of linearity)
5.2. Using the evaluation system prepared in (1), the grid 460 was displayed on the screen 120U of the liquid crystal panel 120 in the same manner as in Example 1, and the amount of deviation Δd at these intersections was measured (see FIG. 17). Similarly to the first embodiment, the measured deviation amount Δd is grouped for each of the lines A to F parallel to the reference direction X, and the measurement result at the intersection on the line III perpendicular to the reference direction X is used as a reference (deviation). Difference in amount Δd = 0.0 μm), the difference in deviation amount Δd at each intersection was organized for each group. The results are shown in FIG. In FIG. 20, a graph surrounded by a frame shows results at intersections on lines A, B, C, D, E, and F of the grid 460 in order from the top. In FIG. 20, the results at the intersections on the lines I, II, III, IV, and V of the grid 460 are shown in order from the left in each of the graphs surrounded by a frame.

  As can be seen from FIG. 20, the difference in the amount of deviation Δd was large in the results of any group. From this, it was found that the anisotropic flow region of the retardation film prepared in Example 5 was inferior in straightness.

[6. Example 6]
Using the result of the shift amount Δd measured in Example 5, the total pitch was evaluated in the same manner as in Example 2.
That is, the shift amount Δd at all the intersections of the grid 460 displayed on the liquid crystal panel 120 was grouped for each of the lines I to V perpendicular to the reference direction X (see FIG. 17). In any group, among the lines A to F parallel to the reference direction X, the shift amount Δd at the intersection on the uppermost line A in the figure is the smallest, and the intersection on the lower line in the figure It was found that the deviation amount Δd was large.

  Therefore, among the lines A to F parallel to the reference direction X, the deviation amount Δd at the intersection on the uppermost line A in the drawing and the deviation amount at the intersection on the lowest line F in the drawing. The amount of difference (difference) from Δd was calculated. The obtained difference amount was divided by 800 pixels (= 160 pixels × 5), which is the number of pixels from line A to line F, to calculate the difference amount per pixel. The results are shown in Table 3.

  From Table 3, it can be seen that the total pitch error of the retardation film prepared in Example 5 is small.

DESCRIPTION OF SYMBOLS 10 2nd phase difference film 11 Anisotropic area | region 12 Isotropic area 13 Boundary line 20 Liquid crystal panel 21 Pixel area 22 Pixel area 23 Black stripe 100 Evaluation system 110 Light source 120 Liquid crystal panel 120U Screen 121 Polarizing film 122 Liquid crystal cell 123 Polarizing film 124 pixel region for right eye 125 pixel region for left eye 126 black matrix 130 retardation film 131 first retardation film 132 second retardation film 133 anisotropic region 134 isotropic region 135 boundary line 140 circular polarization filter 150 micro Scope 160 Grating 161a to 161f Line 162i to 162v Line 163ai to 163fi, 163aii to 163av Intersection 164a Reference line 200 Evaluation system 220 Multilayer black stripe film 221 Polarizing film Lum 222 Black stripe film 223 Substrate 224 Black stripe 225 Translucent area 260ai-260ci, 260aii, 260aiii Observed point 261 Bright part 262 Dark part 263 Reference line 264 Part lacking bright part 300 Evaluation system 330 Phase difference film 331 First One anisotropic region 332 Second anisotropic region 333 Boundary line 400 Evaluation system 460 Lattice

Claims (13)

In an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order, an evaluation method for evaluating the retardation film,
The reference member includes a polarizer and has a light-transmitting region extending in one reference direction,
The retardation film includes a first retardation film having a uniform retardation in a plane in an effective region of the retardation film, and a plurality of anisotropic regions and isotropic regions extending in one direction. A second retardation film having alternating in
By illuminating the light source, observing a plurality of points in the reference direction of the translucent region of the reference member with the photodetector without attaching the polarizing filter, a reference line parallel to the reference direction is obtained. The same setting at the plurality of points, and the amount of deviation between the reference line and the edge of the portion where the light emitted from the light source is detected by attaching the polarizing filter and observing with the photodetector Measuring and
An evaluation method for evaluating linearity of the anisotropic region and the isotropic region of the second retardation film from a difference between the plurality of points in the reference direction of the deviation amount. The reference member is a liquid crystal panel;
The light-transmitting region of the reference member is a pixel region of the liquid crystal panel;
The evaluation method according to claim 1, wherein observation with the photodetector is performed in a state where a lattice having a line parallel to the reference direction and a line perpendicular to the reference direction is displayed on the liquid crystal panel. The reference member includes a substrate capable of transmitting light emitted from the light source, and a plurality of black stripes formed on the substrate and extending in parallel with the reference direction,
The evaluation method according to claim 1, wherein the light-transmitting region of the reference member is provided between the black stripes.   The evaluation method according to claim 1, wherein the polarizing filter is a circular polarizing filter.   The evaluation method as described in any one of Claims 1-4 whose phase difference of said 1st phase difference film is 1/4 wavelength.   The evaluation method as described in any one of Claims 1-5 whose phase difference of the said anisotropic area | region of said 2nd phase difference film is 1/2 wavelength. In an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order, an evaluation method for evaluating the retardation film,
The reference member includes a polarizer and has a light-transmitting region extending in one reference direction,
The retardation film has a plurality of anisotropic regions extending in one direction and having different slow axis directions alternately in a plane,
By illuminating the light source, observing a plurality of points in the reference direction of the translucent region of the reference member with the photodetector without attaching the polarizing filter, a reference line parallel to the reference direction is obtained. The same setting at the plurality of points, and the amount of deviation between the reference line and the edge of the portion where the light emitted from the light source is detected by attaching the polarizing filter and observing with the photodetector Measuring and
The evaluation method which evaluates the linearity of the said anisotropic area | region of the said retardation film from the difference between these points in the said reference direction of the said deviation | shift amount. The reference member is a liquid crystal panel;
The light-transmitting region of the reference member is a pixel region of the liquid crystal panel;
The evaluation method according to claim 7, wherein observation with the photodetector is performed in a state where a lattice having a line parallel to the reference direction and a line perpendicular to the reference direction is displayed on the liquid crystal panel. The reference member includes a substrate capable of transmitting light emitted from the light source, and a black stripe formed on the substrate and extending in parallel with the reference direction,
The evaluation method according to claim 7, wherein the light-transmitting region of the reference member is provided between the black stripes.   The evaluation method according to any one of claims 7 to 9, wherein the polarizing filter is a circular polarizing filter.   The evaluation method according to any one of claims 7 to 10, wherein a retardation of the anisotropic region of the retardation film is a quarter wavelength. In an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order, an evaluation method for evaluating the retardation film,
The reference member includes a polarizer and has a plurality of light transmitting regions extending in one reference direction,
The retardation film includes a first retardation film having a uniform retardation in a plane in an effective region of the retardation film, and a plurality of anisotropic regions and isotropic regions extending in one direction. A second retardation film having alternating in
By illuminating the light source, a plurality of points in the direction perpendicular to the reference direction of the light-transmitting region of the reference member are observed with the photodetector without attaching the polarizing filter, and are parallel to the reference direction. The same reference line at the plurality of points, and the edge of the portion where the reference line and the light emitted from the light source are detected by attaching the polarizing filter and observing with the photodetector Measuring the amount of deviation from
An evaluation method for evaluating the pitch accuracy of the anisotropic region and the isotropic region of the second retardation film from the difference between the plurality of points in a direction perpendicular to the reference direction of the deviation amount. In an evaluation system comprising a light source, a reference member, a retardation film, a detachable polarizing filter, and a photodetector in this order, an evaluation method for evaluating the retardation film,
The reference member includes a polarizer and has a plurality of light transmitting regions extending in one reference direction,
The retardation film has a plurality of anisotropic regions extending in one direction and having different slow axis directions alternately in a plane,
By illuminating the light source, a plurality of points in the direction perpendicular to the reference direction of the light-transmitting region of the reference member are observed with the photodetector without attaching the polarizing filter, and are parallel to the reference direction. The same reference line at the plurality of points, and the edge of the portion where the reference line and the light emitted from the light source are detected by attaching the polarizing filter and observing with the photodetector Measuring the amount of deviation from
The evaluation method of evaluating the accuracy of the pitch of the anisotropic region of the retardation film from the difference between the plurality of points in a direction perpendicular to the reference direction of the deviation amount.

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