Image display device

Abstract

The present invention addresses the problem of providing an image display device having a small color difference. This image display device has a polarizer, a phase difference layer, and an image display element in this order, the angle formed by the absorption axis of the polarizer and the in-plane slow axis of the phase difference layer being 45 + / -5 DEG, and satisfying a prescribed relationship.

Description

Technical Field

[0001] This invention relates to an image display device. Background Technology

[0002] In flat panel display devices such as organic electroluminescent (EL) image display devices, a phase retardation layer and a polarizer are typically provided for optical compensation of the image display device. Patent Document 1 discloses an image display device with specific optical characteristics. Previous technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-076826 Summary of the Invention The technical problem to be solved by the invention

[0004] When setting the display of an image display device to black and white, it is required that the hue difference (hereinafter also referred to as "hue difference") between the hue of the front view of the image display device and the hue of the tilted view of the image display device be small. The inventors studied the image display device described in Patent Document 1 and found that there is room for improvement in color tone difference.

[0005] Therefore, the objective of this invention is to provide an image display device with small tonal differences. means for solving technical problems

[0006] As a result of in-depth research conducted by the inventors to solve the above-mentioned problems, they discovered that the above-mentioned problems can be solved according to the following structure.

[0007] (1) An image display device, comprising, in sequence, a polarizer, a phase difference layer, and an image display element, wherein, The angle between the absorption axis of the aforementioned polarizer and the in-plane slow axis of the aforementioned phase difference layer is 45±5°. The image display device satisfies the relationships of equations (1) to (9) described later. (2) The image display device according to (1), wherein, Rf 450 (45) M and Rs 450 (45) M is all between -25 and -5 nm. Rf 550 (45) M and Rs 550 (45) M is all between -15 and 5 nm. Rf 650 (45) M and Rs 650 (45) M is -10 to 10 nm. (3) The image display device according to (1) or (2) also satisfies the relationship of equation (3-1) described later, the relationship of equation (6-1) described later and the relationship of equation (9-1) described later. (4) The image display device according to any one of (1) to (3), wherein, The phase difference layer has an A plate and a C plate. Invention Effects

[0008] According to the present invention, an image display device with small tonal differences can be provided. Attached Figure Description

[0009] Figure 1 This is a cross-sectional schematic diagram of one embodiment of the image display device of the present invention. Figure 2 This is a schematic diagram showing the relationship between the absorption axis AA of the polarizer 20 and the in-plane slow axis SA of the phase difference layer 30 in the image display device 10. Figure 3 This is a diagram used to illustrate color differences. Figure 4 It is a schematic diagram showing the relationship between the terms in equations (1) to (3). Figure 5 It is used for Rf 450 (45) A diagram illustrating the positive and negative values ​​of M. Figure 6 From Figure 5 A diagram illustrating the direction of the blackened arrow when observing. Figure 7 From Figure 5 and Figure 6 A diagram illustrating the direction of the hollow arrow in the image. Detailed Implementation

[0010] The present invention will now be described in detail. The description of the constituent elements described below is sometimes based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.

[0011] In this specification, the numerical range indicated by “~” refers to the range encompassed by the values ​​recorded before and after “~” as the lower and upper limits. In this specification, "visible light" refers to light in the wavelength range of 380–780 nm. Furthermore, unless otherwise specified, the wavelength to be measured is 550 nm. In this specification, "in-plane slow axis" refers to the direction of maximum in-plane refractive index. "In-plane fast axis" refers to the direction of minimum in-plane refractive index.

[0012] In this specification, Re(λ) and Rth(λ) represent the in-plane delay and the thickness delay at wavelength λ, respectively. Unless otherwise specified, wavelength λ is set to 550 nm. Re(λ) and Rth(λ) are values ​​measured at wavelength λ in AxoScan, manufactured by Axometrics. The following values ​​are calculated by inputting the average refractive index ((nx+ny+nz) / 3) and film thickness (d(μm)) into AxoScan. Slow axis direction (°) Re(λ) = R0(λ) Rth(λ)=((nx+ny) / 2-nz)×d Additionally, R0(λ) represents the value calculated by AxoScan, which refers to Re(λ).

[0013] In this specification, the refractive indices nx, ny, and nz are measured using an Abbe refractometer (NAR-4T, manufactured by ATAGO CO.,LTD.) and a sodium lamp (λ=589nm) as the light source. Furthermore, when measuring wavelength dependence, measurements can be performed using a multi-wavelength Abbe refractometer DR-M2 (manufactured by ATAGO CO.,LTD.) combined with an interference filter. Furthermore, values ​​from the polymer handbook (JOHN WILEY & SONS, INC) and various optical film product catalogs can be used. The following are examples of the average refractive index values ​​for major optical films: cellulose acylate (1.48), cyclic olefin polymer (1.52), polycarbonate (1.59), polymethyl methacrylate (1.49), and polystyrene (1.59).

[0014] In this specification, the A-board and C-board are defined as follows. There are two types of A-plates: positive A-plates and negative A-plates. When the refractive index along the slow axis (where the in-plane refractive index is at its maximum) is set as nx, the refractive index along the direction orthogonal to the slow axis is set as ny, and the refractive index along the thickness direction is set as nz, the positive A-plate satisfies equation (A1), while the negative A-plate satisfies equation (A2). Furthermore, the Rth value for a positive A-plate is positive, while the Rth value for a negative A-plate is negative. Equation (A1) nx>ny≈nz Equation (A2) ny<nx≈nz Furthermore, the aforementioned “≈” includes not only cases where the two are completely identical, but also cases where they are substantially identical. “Substantially identical” means, for example, that even when (ny-nz)×d (where d is the film thickness) is -10 to 10 nm, preferably -5 to 5 nm, it is included in “ny≈nz”, and even when (nx-nz)×d is -10 to 10 nm, preferably -5 to 5 nm, it is included in “nx≈nz”. There are two types of C-plates: positive C-plates and negative C-plates. Positive C-plates satisfy the relationship in equation (C1), while negative C-plates satisfy the relationship in equation (C2). In addition, Rth represents a negative value for positive C-plates and a positive value for negative C-plates. Equation (C1) nz>nx≈ny Equation (C2) nz<nx≈ny Furthermore, the aforementioned “≈” not only includes cases where the two are completely identical, but also cases where they are substantially identical. “Substantially identical” means that, for example, the case where (nx-ny)×d (where d is the film thickness) is 0 to 10 nm, preferably 0 to 5 nm, is also included in “nx≈ny”.

[0015] Furthermore, in this specification, the "fixed" state refers to the state in which the orientation of the liquid crystal compound is maintained. Specifically, the preferred state is one in which the layer does not flow under normal conditions of 0 to 50°C, or more severe conditions of -30 to 70°C, and its orientation morphology does not change due to external fields or forces, thus stably and continuously maintaining a fixed orientation morphology.

[0016] [Image display device] Hereinafter, an embodiment of the image display device of the present invention will be described with reference to the accompanying drawings. Figure 1 This is a cross-sectional view showing one embodiment of the image display device of the present invention. Please note that the figures in this invention are schematic diagrams, and the thickness and positional relationships of the layers may not necessarily correspond to actual thickness or positional relationships. The same applies to the following figures. The image display device 10 has a polarizer 20, a phase difference layer 30 and an image display element 40 in sequence from the visual recognition side (the upper side in the figure, in the z-axis direction).

[0017] As a feature of the image display device of the present invention, it can be cited that all of them satisfy the relationship of equations (1) to (9) described later. By satisfying the relationship of equations (1) to (9) described above, the color difference becomes smaller.

[0018] Furthermore, in Figure 2The figure shows the relationship between the absorption axis AA of the polarizer 20 in the image display device 10 and the in-plane slow axis SA of the phase difference layer 30. Figure 2 In the middle, the in-plane slow axis SA of the retardation layer 30 is parallel to the x-axis, and the angle between the absorption axis AA of the polarizer 20 and the in-plane slow axis SA of the retardation layer 30 is 45°. Additionally, in Figure 2 In this invention, the absorption axis AA of the polarizer 20 is located at a position 45° counterclockwise relative to the in-plane slow axis SA of the phase difference layer 30. However, the invention is not limited to this method, and the absorption axis AA of the polarizer 20 can also be located at a position 45° clockwise relative to the in-plane slow axis SA of the phase difference layer 30. and, Figure 3 The diagram illustrates the tonal difference. As described above, the tonal difference of the image display device 10 of the present invention is small. Specifically, this means that when the display of the image display device 10 is set to black, under bright light, the tonal difference is small from the direction parallel to the z-axis of the image display device 10. Figure 3 The hue of the hollow arrow in the image is visually recognized from the 45° polar angle. Figure 3 The difference in hue during visual recognition is small in the direction of the blackened arrow (the tilt direction of the image display device 10). In addition, the line projected onto the image display element 10 in the direction of the blackened arrow is preferably parallel to the in-plane slow axis SA or the in-plane fast axis FA of the phase difference layer 30.

[0019] <Polarizer> The image display device 10 has a polarizer 20. The polarizer 20 is a component that has the function of converting natural light (unpolarized light) into specific linearly polarized light. Examples of polarizers 20 include iodine-based polarizers, dye-based polarizers using dichroic substances, and polyolefin-based polarizers, which are absorption-type polarizers. Iodine-based polarizers and dye-based polarizers are manufactured, for example, by adsorbing iodine or a dichroic substance onto polyvinyl alcohol and then stretching it. Furthermore, a protective film may be provided on one or both sides of the polarizer 20.

[0020] There is no particular limitation on the thickness of the polarizer 20, but from the viewpoint of excellent operability and optical characteristics, it is preferably 35 μm or less, and more preferably 1 to 25 μm. Furthermore, the thickness of the polarizer 20 refers to the average thickness of the polarizer 20. This average thickness is calculated by measuring the thickness at any five or more points on the polarizer 20 and then taking their arithmetic average. In the case of specific values ​​for the thickness of a layer, as described above, the values ​​are obtained by measuring the thickness of any 5 or more points of a certain layer and taking the arithmetic mean of them.

[0021] <Phase Difference Layer> The image display device 10 has a phase difference layer 30. The angle between the absorption axis AA of the polarizer 20 and the in-plane slow axis SA of the phase difference layer 30 is 45°, but it is not limited to these arrangements. In the image display device, the angle is 45±5° (range 40 to 50°), preferably 45±3° (range 42 to 48°), and more preferably 45°.

[0022] The phase difference layer 30 preferably has a λ / 4 plate. The phase retardation layer 30 more preferably comprises a λ / 4 plate and an optical anisotropy layer, and even more preferably comprises a λ / 4 plate and an optical anisotropy layer sequentially from the visual recognition side. That is, it is even more preferable that the phase retardation layer 30 comprises a λ / 4 plate and an optical anisotropy layer sequentially from the visual recognition side. Figure 1 The arrow pointing towards the origin along the z-axis has a λ / 4 plate and an optical anisotropy layer in sequence. The optical anisotropy layer is preferably an optical anisotropy layer other than the λ / 4 plate described later (e.g., a positive C plate). Furthermore, the phase retardation layer 30 preferably has an A plate and a C plate, and more preferably has a positive A plate and a positive C plate in sequence. Furthermore, the λ / 4 plate can be a broadband λ / 4 plate, which is a stack of λ / 2 plates and λ / 4 plates. A λ / 4 plate is a plate that has the function of converting linearly polarized light of a specific wavelength into circularly polarized light (or converting circularly polarized light into linearly polarized light), and is a plate whose Re(λ) satisfies λ / 4. The λ / 4 plate is preferably plate A, and more preferably positive plate A. The angle between the in-plane slow axis of the λ / 4 plate and the absorption axis AA of the polarizer 20 is preferably 45±5°, more preferably 45±3°, and even more preferably 45°.

[0023] The Re(450) of the λ / 4 plate is preferably 90-135 nm, more preferably 90-125 nm, and even more preferably 100-120 nm. The Re(550) of the λ / 4 plate is preferably 110-160 nm, more preferably 110-150 nm, and even more preferably 130-150 nm. The Re(650) of the λ / 4 plate is preferably 130-190 nm, more preferably 130-180 nm, and even more preferably 140-160 nm. The λ / 4 plate can be either positive wavelength dispersion or negative wavelength dispersion, with negative wavelength dispersion being preferred. Furthermore, negative wavelength dispersion is preferably displayed in the visible light region. In this specification, "reverse wavelength dispersion" means that when measuring the Re value in the visible light range of the phase difference layer, the Re value remains the same or increases with the increase of the measurement wavelength.

[0024] The thickness of the λ / 4 plate is preferably 1.0 to 10.0 μm, more preferably 1.0 to 5.0 μm.

[0025] As a method for manufacturing the λ / 4 plate, one example is the method of obtaining it by horizontally aligning a rod-shaped polymeric liquid crystal compound. For example, the manufacturing methods of the positive A plate disclosed in Japanese Patent Application Publication Nos. 2008-225281 and 2008-026730 are examples. As a method for manufacturing a λ / 4 plate with reverse wavelength dispersion, one example is the method of obtaining it by horizontally aligning a liquid crystal compound with reverse wavelength dispersion. Examples of liquid crystal compounds with reverse wavelength dispersion include compounds represented by general formula (I) as described in Japanese Patent Application Publication No. 2008-297210 (especially the compounds described in paragraphs

[0034] to

[0039] ), compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2010-084032 (especially the compounds described in paragraphs

[0067] to

[0073] ), and compounds represented by general formula (1) as described in Japanese Patent Application Publication No. 2016-081035 (especially the compounds described in paragraphs

[0043] to

[0055] ).

[0026] The phase difference layer 30 preferably has an optical anisotropy layer other than the λ / 4 plate mentioned above. The optical anisotropic layer is preferably an optical anisotropic layer with a phase difference in the thickness direction, more preferably a C-plate, and even more preferably a positive C-plate.

[0027] The Rth (450) of the optical anisotropic layer is preferably -140 to -40 nm, more preferably -120 to -60 nm, and even more preferably -120 to -70 nm. The Rth (550) of the optical anisotropic layer is preferably -120 to -20 nm, more preferably -110 to -40 nm, and even more preferably -100 to -50 nm. The Rth (650) of the optical anisotropic layer is preferably -110 to -10 nm, more preferably -100 to -30 nm, and even more preferably -90 to -60 nm. The optical anisotropic layer can be either positive wavelength dispersion or reverse wavelength dispersion, preferably positive wavelength dispersion.

[0028] The thickness of the optical anisotropic layer is preferably less than 10.0 μm, more preferably 0.1 to 5.0 μm, and even more preferably 0.3 to 2.0 μm.

[0029] As a method for manufacturing an optical anisotropic layer, one example is the method of obtaining it by vertically aligning a rod-shaped polymeric liquid crystal compound. For example, the manufacturing methods of the positive C-plate described in Japanese Patent Application Publication Nos. 2017-187732, 2016-053709, and 2015-200861 are examples.

[0030] <Image display element> The image display device 10 has an image display element 40. The image display element 40 is a display element having a pair of electrodes and a light-emitting layer sandwiched therebetween. The reflection phase difference of the image display element 40 can be either positive wavelength dispersion or negative wavelength dispersion, preferably negative wavelength dispersion. As an image display element 40, examples include organic EL display elements, micro LED display elements, and plasma display elements, with organic EL display elements or micro LED display elements being preferred. In addition to the light-emitting layer, the image display element 40 may also have layers such as a hole injection layer, a hole transport layer, an electron injection layer, an electron transport layer, and a protective layer between its electrodes. Each of these layers may have other functions. Various materials can be used to form each layer. Furthermore, the image display element 40 is an element that does not contain components for optical compensation on the image display surface. The image display element 40 can function as a C-plate. As mentioned above, examples of C-plates include a positive C-plate and a negative C-plate. Furthermore, the optical characteristics of the image display element 40 can be changed according to the wavelength. For example, the characteristics of the negative C plate can be displayed on the short wavelength side (e.g., wavelengths of 450nm and 550nm), and the characteristics of the positive C plate can be displayed on the long wavelength side (e.g., wavelength of 650nm).

[0031] <Other Components> In addition to the components mentioned above, the image display device may also have other components. Other components include, for example, adhesive layers and alignment films. The image display device preferably has adhesive layers between the components. As an adhesive layer, examples include known adhesive layers and known bonding agent layers. As an alignment film, known alignment films can be used. Furthermore, the image display element may include a touch panel layer. As long as the image display element has a built-in touch panel layer, a touch panel layer may also be added on top of the image display element. Furthermore, the image display device can have a cover glass on the outermost surface, which is closer to the visual recognition side than the polarizer.

[0032] [Relational Formula] The image display device of the present invention satisfies the relationship of equations (1) to (9).

[0033] Figure 4 It is a diagram showing the relationship between the terms in equations (1) to (3). exist Figure 4 In the middle, the phase difference layer 30 has an in-plane slow axis SA in the direction parallel to the x-axis and an in-plane fast axis FA in the direction parallel to the y-axis. R 450 (0) is the in-plane delay of the retardation layer 30 at a wavelength of 450 nm, which is the delay corresponding to the normal direction relative to the surface of the retardation layer 30. Figure 4 The in-plane delay (Re(450)) of the phase retardation layer 30 in the direction of the hollow arrow (parallel to the z-axis direction). That is, the in-plane delay (Re(450)) of the phase retardation layer 30 is measured from the normal direction relative to the surface of the phase retardation layer 30. Furthermore, Rf 450 (45) is the rotation axis about the in-plane fast axis FA of the phase difference layer 30, as shown by the black arrow, from the normal direction relative to the surface of the phase difference layer 30 ( Figure 4 (Direction of the hollow arrow) Inclined polar angle f( The direction of f=45° is the first direction ( Figure 4 The phase difference at a wavelength of 450 nm for phase difference layer 30 (referencing the black dashed line) was measured. On the other hand, Rs... 450 (45) is the rotation axis about the in-plane slow axis SA of the phasing layer 30, as shown by the black arrow, from the normal direction relative to the surface of the phasing layer 30 ( Figure 4 (Direction of the hollow arrow) Inclined polar angle s ( The direction of s=45° is the third direction ( Figure 4 The phase difference of the phase difference layer 30 at a wavelength of 450 nm was measured (referencing the black dotted line). In addition, the relationship between the terms in equations (1) to (3) will be explained in detail in the latter part. However, the relationship between the terms in equations (4) to (9) is the same as the relationship between the terms mentioned above, except that the measurement wavelength is different.

[0034] <Relationship between equations (1) to (3)> Equation (1) α 450 =R 450 (0)-{Rf 450 (45) + (Rf) 450 (45)M / 2)} α in equation (1) 450This represents the phase difference (Rf) of the phase difference layer measured from the first direction at a wavelength of 450 nm. 450 (45) and the phase difference (Rf) of image display elements at a wavelength of 450nm 450 (45) Half of the total phase difference and the in-plane delay of the phase difference layer (R) 450 The difference between (0) and α 450 The smaller the value, the smaller the hue difference between the hue in the front direction of the image display device and the hue in the first direction of the image display device.

[0035] R 450 (0) indicates the in-plane delay at a wavelength of 450nm for the phase difference layer. In other words, R 450 (0) is the in-plane delay (Re(450)) of the retardation layer at a wavelength of 450 nm, measured from the normal direction (thickness direction of the retardation layer) relative to the surface of the retardation layer. R 450 (0) is preferably 90-135nm, more preferably 90-125nm, and even more preferably 100-120nm. R 450 (0) For example, it can be measured using AxoScan (manufactured by Axometrics).

[0036] Rf 450 (45) represents the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the first direction, which is the direction with a polar angle of 45° relative to the normal direction of the phase difference layer and the in-plane fast axis of the phase difference layer as the rotation axis. Rf 450 (45) is the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the first direction described above. Preferably, it is the sum of the phase differences at a wavelength of 450 nm for each layer constituting the phase difference layer, measured from the first direction described above. For example, if the phase difference layer is composed of a first layer, a second layer, a third layer, and... an nth layer, Rf 450 (45) Preferably, it is the sum of the phase difference of the first layer at a wavelength of 450nm, the phase difference of the second layer at a wavelength of 450nm, the phase difference of the third layer at a wavelength of 450nm, and ... the phase difference of the nth layer at a wavelength of 450nm. Specifically, in the case where the phase retardation layer in an image display device has a λ / 4 plate and an optical anisotropy layer, Rf 450 (45) The phase difference of the λ / 4 plate measured from the first direction and the phase difference of the optical anisotropic layer measured from the first direction are used to determine the phase difference. Rf 450(45) Preferably 90-180nm, more preferably 100-160nm, and even more preferably 110-140nm. Rf 450 (45) For example, it can be measured using AxoScan (manufactured by Axometrics).

[0037] Rf 450 (45) M represents the phase difference at a wavelength of 450 nm, calculated based on the change in polarization state of the measured light and the reflected light received from the image display element from the first direction. Specifically, when measuring the phase difference at a wavelength of 450 nm, the surface containing the first direction and the normal direction relative to the surface of the image display element is designated as the first surface. The direction with a polar angle of 45° relative to the normal direction of the surface of the image display element in an azimuth angle 180° away from the first direction is designated as the second direction. When the surface with the second direction as its normal direction is designated as the second surface, and the slow axis is represented in the direction parallel to the first surface in the second surface, Rf... 450 (45) The value of the phase difference represented by M is a positive value. In the second plane, when the slow axis is represented in the direction orthogonal to the first plane, it is represented by Rf. 450 (45) The phase difference represented by M is represented by a negative value. Additionally, Rf 450 (45) Half of M is the phase difference between the forward and complex paths of the image display element at a wavelength of 450 nm. Here, it is assumed that the phase difference of the forward path and the phase difference of the complex path are the same value. Furthermore, Rf was measured. 450 (45) There are no particular restrictions on the object of measurement at time M, and it can be an image display element alone. When the object of measurement is an image display element alone, imagine an image display device made using this image display element and the aforementioned retardation layer, etc., and the first direction of the measurement light incident on the image display element is the direction corresponding to the first direction in the retardation layer of the assumed image display device. In other words, the measurement light for the image display element alone is incident from the image display device in the direction corresponding to the first direction of the retardation layer without changing the arrangement relationship with the retardation layer, thus obtaining the first direction of the image display element alone from the image display device. Moreover, there are no particular restrictions on the method of obtaining the image display element alone, and it can be a method of making the image display element alone, or it can be a method of removing the image display element from the image display device.

[0038] For equation (1), "Rf" 450 (45) M / 2)” is explained in terms of “1 / 2”. Rf 450(45) The phase difference (reflection phase difference) of M is measured as described later by incident measurement light into the image display element from the first direction and receiving the reflected light reflected by the image display element. Furthermore, it is assumed that most of the measurement light is reflected in the electrode portion located inside the image display element (between the surfaces of the image display element opposite to the incident surface). In this case, the light received by the light is essentially transmitted twice inside the image display element in a total of two paths: the forward path before reflection and the reverse path after reflection. Therefore, the measured phase difference is also affected by the phase difference of the image display element twice. Furthermore, even if the part causing the reflection is the surface of the display element, it is considered that the film thickness of the reflective layer on the surface and inside is extremely thin. Therefore, the phase difference measured in the above measurement method is equivalent to twice the phase difference corresponding to the forward or reverse path of the reflection of the image display element. When using the calculation formulas (1) to (9), in order to match the optical anisotropic layer that is assumed to be transmitted once, half of the measured value is used as the phase difference of the image display element, i.e., "Rf". 450 (45) The value of M / 2”. In addition, the same applies to the formulas described below.

[0039] Figure 5 It is used to explain Rf 450 (45) A graph showing the positive and negative values ​​of M. Regarding Rf 450 (45) The sign of the value of M is determined by the slow axis on a specific plane when measuring the phase difference at a wavelength of 450 nm, as described above. exist Figure 5 In the image display element 40, a surface including a first direction 50 (polar angle 45°) and a normal direction relative to the surface of the image display element is designated as a first surface (not shown). As indicated by the black dotted line, in an azimuth angle deviating 180° from the first direction 50, a direction inclined at a polar angle of 45° relative to the normal direction of the surface of the image display element is designated as a second direction 51. When a surface with the second direction 51 as its normal direction is designated as a second surface 60, in the second surface 60, if the slow axis is represented in a direction parallel to the first surface, Rf... 450 (45) The value of M is positive. In the second plane 60, when the slow axis is represented in the direction orthogonal to the first plane, the value of Rf450(45)M is negative. In addition, from Figure 5 The diagram showing the direction of the blackened arrow is shown in the image. Figure 6 From Figure 5 The diagram showing the direction of the hollow arrow is shown in the image. Figure 7 .

[0040] Figure 6 From Figure 5 The diagram showing the direction of the blackened arrow. exist Figure 6 In the diagram, it is indicated that the second direction 51 is set as the second surface 60 of the normal direction, and the angle between the first direction 50 and the second direction 51 is 90°. Figure 6 The first direction 50, the second direction 51, and the normal direction shown are all contained on the same plane (the first plane). Figure 5 The direction of the blackened arrow shown is parallel to the normal direction of the first surface. That is, in the first surface that includes the first direction 50 and the normal direction of the surface relative to the image display element 40, the direction at 90° to the first direction 50 corresponds to the second direction 51. then, Figure 7 The text appears to be a mix of Chinese characters and symbols, possibly from different sources. A direct translation wouldn't be meaningful. Figure 5 and Figure 6 The diagram showing the direction of the hollow arrow in the image. exist Figure 7 The diagram is shown with the second direction 51 positioned at the center of the second surface 60. Here, the measurement is performed using Rf... 450 (45) When M represents the phase difference, in the second plane 60, in the direction parallel to the first plane (and) Figure 7 In the case of the slow axis (representing the highest refractive index), Rf (corresponding to the a-axis direction) 450 (45) The value of M is expressed as a positive value. On the other hand, in the determination of Rf 450 (45) When M represents the phase difference, in the second plane 60, in the direction orthogonal to the first plane (and) Figure 7 In the case of the slow axis (representing the highest refractive index), Rf (corresponding to the b-axis direction) 450 (45) The value of M is represented by a negative value. For example, when the phase difference of the image display element at a wavelength of 450 nm is measured according to the above steps, the magnitude (absolute value) of the phase difference is 20 nm, and in the direction parallel to the first surface (and... Figure 7 When the slow axis is represented on the plane corresponding to the a-axis direction, the phase difference is set to +20 nm. The direction of the slow axis in the second plane can be determined based on the analysis results of the reflectance-type ellipsometer described later. In addition, when performing analysis based on the reflectance-type ellipsometer, it is preferable to arrange the receiver in the second direction. Rf 450 (45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -25 to -5 nm.

[0041] Rf 450 (45) M can be determined, for example, using a reflectance ellipsometry. Furthermore, in measuring Rf 450(45) When M is reached, an isotropic refractive index layer can be provided on the surface of the image display element. Furthermore, it is preferable that the surface of the isotropic refractive index layer is smooth. With the aforementioned smooth isotropic refractive index layer provided, Rf can be easily and accurately measured even in an air environment. 450 (45)M. Examples of isotropic refractive index layers include synthetic quartz or fused silica. Furthermore, the isotropic refractive index layer is preferably laminated onto the surface of the image display element, with a refractive index matching oil and adhesive layer as a buffer. In addition, in order to reduce the influence of reflection at the interface between the surface of the isotropic refractive index layer and air, or at the interface between the aforementioned adjustment layer and other layers in contact with it (e.g., image display elements and fused silica), measures such as increasing the thickness of the isotropic refractive index layer, tilting the image display element by 0.5° or more within a measurable range, or deviating the light source or receiver by 0.5° or more in the polar angle direction, or deviating the light source or receiver by 0.5° or more in the azimuth direction, can be taken.

[0042] Equation (2) β 450 =R 450 (0)-{Rs 450 (45)-(Rs) 450 (45)M / 2)} β in equation (2) 450 β represents the difference between the total phase difference (measured from the third direction at 450 nm) and half the phase difference of the image display element at 450 nm, and the in-plane delay of the phase difference layer, i.e., β. 450 The smaller the value, the smaller the hue difference between the hue in the front direction of the image display device and the hue in the third direction of the image display device.

[0043] R in equation (2) 450 (0) and R of equation (1) 450 (0) has the same meaning and the same preferred method.

[0044] Rs 450 (45) represents the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the third direction, which is the direction with a polar angle of 45° relative to the normal direction of the phase difference layer and the in-plane slow axis of the phase difference layer as the rotation axis. Rs 450 (45) is the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the third direction described above. Preferably, it is the sum of the phase differences at a wavelength of 450 nm of each layer constituting the phase difference layer, measured from the third direction described above. For example, if the phase difference layer is composed of a first layer, a second layer, a third layer, and... an nth layer, Rs 450(45) Preferably, it is the sum of the phase difference of the first layer at a wavelength of 450nm, the phase difference of the second layer at a wavelength of 450nm, the phase difference of the third layer at a wavelength of 450nm, and ... the phase difference of the nth layer at a wavelength of 450nm. Specifically, in the case where the phase retardation layer in an image display device has a λ / 4 plate and an optical anisotropy layer, Rs 450 (45) The phase difference is determined from the phase difference of the λ / 4 plate measured from the third direction and the phase difference of the optical anisotropic layer measured from the third direction. Rs 450 (45) Preferably 80-140nm, more preferably 90-130nm, and even more preferably 100-120nm. Rs 450 (45) For example, it can be measured using AxoScan (manufactured by Axometrics).

[0045] Rs 450 (45) M represents the phase difference at a wavelength of 450 nm, calculated based on the change in polarization state of the measured light and the reflected light received from the image display element from the third direction. Specifically, when measuring the phase difference at a wavelength of 450 nm, the surface containing the third direction and the normal direction relative to the surface of the image display element is designated as the third surface. The direction with a polar angle of 45° relative to the normal direction of the image display element in an azimuth angle 180° away from the third direction is designated as the fourth direction. When the surface with the fourth direction as its normal direction is designated as the fourth surface, and the slow axis is represented in the direction parallel to the third surface, Rs... 450 (45) The value of the phase difference represented by M is a positive value. In the fourth plane, in the case of representing the slow axis in the direction orthogonal to the third plane, it is represented by Rs. 450 (45) The phase difference represented by M is represented by a negative value. Rs 450 (45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -25 to -5 nm. By Rs 450 (45) The sign of the phase difference value represented by M is determined by the relationship between Rf and M. 450 (45) The phase difference value represented by M is determined by the method of having the same sign. Furthermore, regarding Rs... 450 (45) The method for determining M, in Rf 450 (45) In the method of measuring M, the first direction is changed to the third direction and the second direction is changed to the fourth direction. Otherwise, the same method can be used to measure M.

[0046] Equation (3) |α 450 |+|β 450 ≤4.0nm The left side of equation (3) represents α 450 The absolute value of β 450 The sum of absolute values ​​of the hues decreases when the sum is below 4.0 nm. |α 450 | Preferably 0–4.0 nm, more preferably 0–3.0 nm, and even more preferably 0–2.5 nm. |β 450 | Preferably 0–4.0 nm, more preferably 0–3.0 nm, and even more preferably 0–2.0 nm. Preferably, the relationship satisfies equation (3-1), and more preferably, the relationship satisfies equation (3-2). Equation (3-1) 0nm≤|α 450 |+|β 450 ≤3.5nm Equation (3-2) 0nm≤|α 450 |+|β 450 ≤3.0nm

[0047] As adjustment α 450 and β 450 Methods for determining the value of the value include, for example, adjusting the refractive index anisotropy (Δn) or d (d = film thickness of the liquid crystal layer) in the optical anisotropy layer described later.

[0048] <Relationship between equations (4) to (6)> Equation (4) α 550 =R 550 (0)-{Rf 550 (45) + (Rf) 550 (45)M / 2)} α in equation (4) 550 Except for changing the measurement wavelength to 550 nm, the meanings of the items in the table are the same as α. 450 The items in the test are the same, and the measurement methods are also the same.

[0049] R 550 (0) is preferably 100-180nm, more preferably 120-160nm, and even more preferably 130-150nm.

[0050] As Rf 550 (45) In the case where the phase retardation layer in the image display device has a λ / 4 plate and an optical anisotropy layer, Rf 550 (45) The phase difference of the λ / 4 plate measured from the first direction and the phase difference of the optical anisotropic layer measured from the first direction are used to determine the phase difference. Rf 550 (45) Preferably 90-180nm, more preferably 100-170nm, and even more preferably 130-160nm.

[0051] Rf 550 (45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -15 to 5 nm.

[0052] Equation (5) β 550 =R 550 (0)-{Rs 550 (45)-(Rs) 550 (45)M / 2)} β in equation (5) 550 Except for changing the measurement wavelength to 550 nm, the meanings of the items in the table are the same as those of β. 450 The items in the test are the same, and the measurement methods are also the same.

[0053] R in equation (5) 550 (0) and R of equation (4) 550 (0) has the same meaning and the same preferred method.

[0054] As Rs 550 (45) In the case where the phase retardation layer in the image display device has a λ / 4 plate and an optical anisotropy layer, Rs 550 (45) The phase difference is determined from the phase difference of the λ / 4 plate measured from the third direction and the phase difference of the optical anisotropic layer measured from the third direction. Rs 550 (45) Preferably 110-170nm, more preferably 120-160nm, and even more preferably 130-150nm.

[0055] Rs 550 (45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -15 to 5 nm.

[0056] Equation (6) |α 550 |+|β 550 |≤4.1nm The left side of equation (6) represents α 550 The absolute value of β 550 The sum of absolute values ​​of the hues decreases when the sum is below 4.1nm. |α 550 | Preferably 0–4.1 nm, more preferably 0–3.0 nm, even more preferably 0–2.5 nm, and especially preferably 0–1.0 nm. |β550 | Preferably 0–4.1 nm, more preferably 0–3.0 nm, even more preferably 0–2.0 nm, and especially preferably 0–1.0 nm. Among them, the relationship that satisfies equation (6-1) is preferred, the relationship that satisfies equation (6-2) is more preferred, and the relationship that satisfies equation (6-3) is even more preferred. Equation (6-1) 0nm≤|α 550 |+|β 550 ≤3.5nm Equation (6-2) 0nm≤|α 550 |+|β 550 ≤3.0nm Equation (6-3) 0nm≤|α 550 |+|β 550 ≤1.0nm

[0057] As adjustment α 550 and β 550 Methods for determining the value of the value include, for example, adjusting the refractive index anisotropy (Δn) or d (d = film thickness of the liquid crystal layer) in the optical anisotropy layer described later.

[0058] <Relationship between equations (7) to (9)> Equation (7) α 650 =R 650 (0)-{Rf 650 (45) + (Rf) 650 (45)M / 2)} α in equation (7) 650 Except for changing the measurement wavelength to 650nm, the meanings of the items in the table are the same as α. 450 The items in the test are the same, and the measurement methods are also the same.

[0059] R 650 (0) is preferably 100-190nm, more preferably 120-180nm, and even more preferably 130-170nm.

[0060] As Rf 650 (45) In the case where the phase retardation layer in the image display device has a λ / 4 plate and an optical anisotropy layer, Rf 650 (45) The phase difference of the λ / 4 plate measured from the first direction and the phase difference of the optical anisotropic layer measured from the first direction are used to determine the phase difference. Rf 650 (45) Preferably 90-180nm, more preferably 100-170nm, and even more preferably 130-160nm.

[0061] Rf 650(45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -10 to 10 nm.

[0062] Equation (8) β 650 =R 650 (0)-{Rs 650 (45)-(Rs) 650 (45)M / 2)} β in equation (8) 650 Except for changing the measurement wavelength to 650 nm, the meanings of the items in the table are the same as those of β. 450 The items in the test are the same, and the measurement methods are also the same.

[0063] R in equation (8) 650 (0) and R of equation (7) 650 (0) has the same meaning and the same preferred method.

[0064] As Rs 650 (45) In the case where the phase retardation layer in the image display device has a λ / 4 plate and an optical anisotropy layer, Rs 650 (45) The phase difference is determined from the phase difference of the λ / 4 plate measured from the third direction and the phase difference of the optical anisotropic layer measured from the third direction. Rs 650 (45) Preferably 140-180nm, more preferably 150-170nm, and even more preferably 140-160nm.

[0065] Rs 650 (45) M is preferably -50 to 50 nm, more preferably -30 to 20 nm, and even more preferably -10 to 10 nm.

[0066] Equation (9) |α 650 |+|β 650 ≤4.0nm The left side of equation (9) represents α 650 The absolute value of β 650 The sum of absolute values ​​of the hues decreases when the sum is below 4.0 nm. |α 650 | Preferably 0–4.0 nm, more preferably 0–3.0 nm, even more preferably 0–2.5 nm, and especially preferably 0–1.5 nm. |β 650 | Preferably 0–4.0 nm, more preferably 0–3.0 nm, even more preferably 0–2.0 nm, and especially preferably 0–1.5 nm. Preferably, the relationship satisfies equation (9-1), and more preferably, the relationship satisfies equation (9-2). Equation (9-1) 0nm≤|α 650 |+|β 650 ≤3.5nm Equation (9-2) 0nm≤|α 650 |+|β 650 ≤3.0nm

[0067] As adjustment α 650 and β 650 Methods for determining the value of the value include, for example, adjusting the refractive index anisotropy (Δn) or d (d = film thickness of the liquid crystal layer) in the optical anisotropy layer described later.

[0068] The image display device preferably comprises a polarizer, an A-plate, a C-plate, and an image display element in sequence. As a preferred method for image display devices, Rf is preferred. 450 (45) M and Rs 450 (45) M is -25 to -5 nm, Rf 550 (45) M and Rs 550 (45) M is -15 to 5 nm, Rf 650 (45) M and Rs 650 (45) M is -10 to 10 nm. As another preferred embodiment of the image display device, it is even more preferred to satisfy the relationships of equation (3-1), equation (6-1), and equation (9-1).

[0069] [Manufacturing method of image display device] There are no particular restrictions on the manufacturing method of the image display device; well-known methods can be used. For example, the following method can be used: after coating a phase retardation layer forming composition containing a specified liquid crystal compound onto a specified substrate to form a coating film, the coating film is oriented, and then a curing process is performed to form a specified phase retardation layer. The formed phase retardation layer and a polarizer are stacked together with an adhesive layer to obtain a laminate, and then the laminate and an image display element are bonded together with an adhesive layer. Furthermore, the phase retardation layer is preferably formed using a phase retardation layer forming composition containing a polymerizable liquid crystal compound.

[0070] The liquid crystal compound is preferably a liquid crystal compound having polymerizable groups (hereinafter also referred to as "polymerizable liquid crystal compound"). The appropriate optimal polymerizable liquid crystal compound is selected based on the formation of each phase retardation layer.

[0071] Polymerizable groups present in polymerizable liquid crystal compounds include, for example, (meth)acryloyl, vinyl, styrene and allyl, with (meth)acryloyl being preferred.

[0072] Liquid crystal compounds can be classified into rod-shaped and disk-shaped types. Furthermore, they can be categorized into low-molecular-weight and high-molecular-weight types. Polymers refer to substances with a degree of polymerization of 100 or higher (Polymer Physics and Phase Transition Dynamics, Masao Doi, p. 2, Iwanami Shoten, 1992). As the liquid crystal compound, rod-shaped liquid crystal compounds or disc-shaped liquid crystal compounds (disc-shaped liquid crystal compounds) are preferred. The liquid crystal compound can be any one of two or more rod-shaped liquid crystal compounds, two or more disc-shaped liquid crystal compounds, or a mixture of rod-shaped liquid crystal compounds and disc-shaped liquid crystal compounds. Examples of rod-shaped liquid crystal compounds include those described in claim 1 of Japanese Patent Application Publication No. 11-513019 and in paragraphs

[0026] to

[0098] of Japanese Patent Application Publication No. 2005-289980. As a disc-shaped liquid crystal compound, examples include the liquid crystal compounds described in paragraphs

[0020] to

[0067] of Japanese Patent Application Publication No. 2007-108732 and paragraphs

[0013] to

[0108] of Japanese Patent Application Publication No. 2010-244038.

[0073] As the aforementioned liquid crystal compound, a rod-shaped liquid crystal compound is preferred. Examples of rod-shaped liquid crystal compounds include azo compounds with azo groups such as methylimine and azo oxides, cyanobiphenyl compounds, cyanophenyl esters, benzoic acid esters, cyclohexane carboxylic acid phenyl esters, cyanophenylcyclohexane compounds, cyano-substituted phenylpyrimidine compounds, alkoxy-substituted phenylpyrimidine compounds, phenyl dioxane compounds, diphenylacetylene compounds, and alkenylcyclohexylbenzonitrile compounds. The rod-shaped liquid crystal compound preferably includes at least one selected from the group consisting of azo compounds and diphenylacetylene compounds.

[0074] As a method to adjust to satisfy the relationships of equations (1) to (9), for example, one method is to adjust the refractive index anisotropy (Δn) or d (d = film thickness of the liquid crystal layer) in the aforementioned phase difference layer (e.g., optical anisotropy layer). Generally, the greater the refractive index anisotropy, the greater the positive wavelength dispersion tends to be (Liquid Crystal Compendium (Liquid Crystal Compendium Editorial Committee, Maruzen Co., Ltd.)). Therefore, as a polymerizable liquid crystal compound, it is preferable to use a polymerizable liquid crystal compound with a large refractive index anisotropy or a large positive wavelength dispersion. Specifically, as a polymerizable liquid crystal compound, it is preferable to use a polymerizable liquid crystal compound having multiple aromatic rings, a polymerizable liquid crystal compound having heteroaromatic rings, a polymerizable liquid crystal compound having a cyclohexane ring, a polymerizable liquid crystal compound having multiple bonds, or a polymerizable liquid crystal compound having fluorine atoms.

[0075] The content of the polymeric liquid crystal compound in the composition for forming the phase retardation layer is preferably 60 to 99% by mass relative to the total solid content of the composition for forming the phase retardation layer, more preferably 70 to 98% by mass. In addition, solid components refer to components that can form a phase difference layer without solvent, and are also defined as solid components even if they are in liquid form.

[0076] The composition for forming the phase retardation layer may contain other components besides polymeric liquid crystal compounds. Other components include, for example, chiral agents, polymerization initiators, multifunctional monomers, orientation control agents (vertical and horizontal orientation agents), surfactants, adhesion improvers, plasticizers, solvents, and photooriented polymers.

[0077] The polymerization initiator is selected according to the form of polymerization reaction; for example, thermal polymerization initiators and photopolymerization initiators can be cited. The content of polymerization initiator in the composition for forming a phase retardation layer is preferably 0.01 to 20% by mass relative to the total solid content of the composition for forming a phase retardation layer, more preferably 0.5 to 10% by mass.

[0078] Examples of coating methods for the composition used to form the phase difference layer include curtain coating, dip coating, spin coating, printing coating, spray coating, slot coating, roller coating, sliding coating, doctor blade coating, gravure coating, and wire rod coating.

[0079] Orientation processing can be performed by drying the coating at room temperature or by heating the coating. When the liquid crystal phase formed during orientation processing is a thermotropic liquid crystal compound, it can typically be transferred according to changes in temperature or pressure. In the case of a lyotropic liquid crystal compound, transfer can also be achieved through compositional ratios such as solvent volume. In addition, there are no particular restrictions on the conditions for heating the coating, but the heating temperature is preferably 50 to 250°C, more preferably 50 to 150°C, and the heating time is preferably 10 seconds to 10 minutes. Furthermore, the coating can be cooled as needed after heating and before the curing process (light irradiation treatment) described later.

[0080] There are no particular limitations on the method of curing the coating film on which the polymeric liquid crystal compound is oriented; for example, light irradiation and heat treatment can be cited. From the viewpoint of manufacturing applicability, light irradiation is preferred, and ultraviolet irradiation is more preferred. There are no particular restrictions on the irradiation conditions for light treatment, but 50–1000 mJ / cm² is preferred. 2 The amount of radiation. There are no particular restrictions on the atmosphere used during light irradiation treatment, but a nitrogen atmosphere is preferred. Furthermore, the "light" in the aforementioned light irradiation treatment refers to activating light or radiation, such as the bright-line spectrum of a mercury lamp, far-ultraviolet light represented by an excimer laser, extreme ultraviolet light (EUV light), X-rays, ultraviolet light, and electron beams (EB). Among these, ultraviolet light is preferred.

[0081] In addition, when other phase retardation layers are formed directly on the phase retardation layer, for example, the photo-oriented polymer can be non-uniformly present on the surface of the phase retardation layer, and the photo-oriented polymer on the surface of the phase retardation layer can be oriented by light irradiation, thereby imparting an orientation constraint force. Example

[0082] The present invention will now be described in further detail with reference to embodiments. The materials, quantities, proportions, processing contents, and processing steps shown in the following embodiments can be appropriately modified as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as limited by the embodiments shown below.

[0083] [Comparative Example 1] <Fabrication of Image Display Elements> The commercially available smartphone (HUAWE P40 Pro) was disassembled, the cover glass and polarizer were removed, the organic EL substrate was extracted, and the organic EL substrate was used as an image display element. Furthermore, based on the results shown in the table below, it was confirmed that the aforementioned image display element exhibits inverse wavelength dispersion.

[0084] <Fabrication of Optical Anisotropic Layer C1> First, the first pseudo-support was created through the following steps. The following components were added to a mixing vessel and stirred, then heated at 90°C for 10 minutes. The resulting mixture was then filtered through filter paper with an average pore size of 34 μm and a sintered metal filter with an average pore size of 10 μm to prepare a concentrated cellulose acylate. The solids concentration of the concentrated cellulose acylate was 23.5% by mass.

[0085] ─────────────────────────────── Cellulose acylate concentrate ─────────────────────────────── Cellulose acylates (Acetyl substitution degree 2.86, average viscosity degree of polymerization 310) 100 parts by weight • 6.0 parts by mass of sugar ester compound 1 (shown in formula (S4) below) • Sugar ester compound 2 (shown in formula (S5) below) 2.0 parts by mass • Silica particle dispersion (AEROSIL R972, manufactured by NIPPON AEROSIL CO.,LTD.) 0.1 parts by weight • Solvents (dichloromethane / methanol / butanol) =81 / 18 / 1 (mass ratio) ───────────────────────────────

[0086] [Chemical Formula 1]

[0087] The aforementioned cellulose acylate concentrate was cast using a roller film forming machine. After the concentrate was cast from the mold and brought into contact with a metal support cooled to 0°C, the resulting sheet (film) was peeled off. The roller was made of SUS steel.

[0088] After the film obtained by casting is peeled off the rollers, it is dried for 20 minutes in a tenter frame at 30–40°C, where the two ends of the film are clamped and conveyed. Then, the film is post-dried by zone heating while being conveyed by rollers. After knurling the obtained film, it is wound to obtain the first pseudo-support (cellulose acylate film). The thickness of the first pseudo-support is 40 μm.

[0089] Using a die-coating machine, the liquid crystal composition 1 described above was coated onto the first pseudo-support to form a composition layer. The first pseudo-support with the composition layer formed was heated at 60°C for 1 minute with warm air, while being purged with nitrogen and irradiated with ultraviolet light (irradiation dose 120 mJ / cm²). 2 Using an ultra-high pressure mercury lamp to create an atmosphere with an oxygen concentration of less than 100 ppm by volume, the orientation of the rod-shaped liquid crystal compound L-1 is fixed, and an optical anisotropic layer C1, which serves as a positive C-plate, is formed. A transfer film 1 having a first pseudo-support and an optical anisotropic layer C1 arranged adjacent to the first pseudo-support is produced. In addition, the thickness of the optical anisotropic layer C1 is 0.6 μm, and the average tilt angle of the polymer derived from the rod-shaped liquid crystal compound L-1 relative to the long axis direction of the transfer film 1 is 90°, and it is perpendicular to the surface of the transfer film 1.

[0090] ─────────────────────────────── Liquid crystal composition 1 ─────────────────────────────── · 100 parts by weight of the following rod-shaped liquid crystal compound L-1 • The following multifunctional monomer M-1 (UA-306I, urethane acrylate monomer, manufactured by KYOEISHA CHEMICAL CO.,LTD.) 5.0 parts by weight • Polymerization initiator (IrgacureOXE01, manufactured by BASF) 4.0 parts by weight • 1.2 parts by weight of the following polymer X-1 · 1.14 parts by weight of the following onium salt compounds • 0.4 parts by weight of the following fluorinated compound (fluoropolymer) F-1 43.3 parts by weight of methyl ethyl ketone 95.0 parts by weight of ethyl propionate 494.9 parts by weight of methyl isobutyl ketone ───────────────────────────────

[0091] Rod-shaped liquid crystal compound L-1

[0092] [Chemical Formula 2]

[0093] Multifunctional monomer M-1

[0094] [Chemical Formula 3]

[0095] Polymer X-1 (The values ​​in the following formula represent the content (mass%) of each repeating unit in the polymer relative to all repeating units. The weight-average molecular weight is 57,000.)

[0096] [Chemical Formula 4]

[0097] Onium salt compounds

[0098] [Chemical Formula 5]

[0099] Fluoropolymer F-1 (The values ​​in the following formula represent the content (mass%) of each repeating unit in the polymer relative to all repeating units. The weight-average molecular weight is 15000.)

[0100] [Chemical Formula 6]

[0101] <Fabrication of Optical Anisotropic Layer A1> The photo-alignment film forming coating solution E1, consisting of the following composition, is continuously coated onto the first dummy support using a wire rod. The first dummy support with the coating is dried with warm air at 134°C for 75 seconds, followed by irradiation with polarized ultraviolet light (8 mJ / cm²). 2 Using an ultra-high pressure mercury lamp, photo-alignment film 1 was formed. The thickness of photo-alignment film 1 is 0.5 μm.

[0102] ─────────────────────────────── Coating solution E1 for photo-aligned film formation ─────────────────────────────── • 100.00 parts by weight of the following polymer PA-1 • 6.00 parts by weight of the following acid-producing agent PAG-1 • 0.60 parts by weight of DIPEA ·Butyl acetate 625.4 parts by weight 156.3 parts by weight of methyl ethyl ketone ───────────────────────────────

[0103] Polymer PA-1 [In the following formula, the values ​​listed for each repeating unit represent the content (mass%) of each repeat relative to all repeating units. Weight-average molecular weight: 45000]

[0104] [Chemical Formula 7]

[0105] Acid-producing agent PAG-1

[0106] [Chemical Formula 8]

[0107] DIPEA

[0108] [Chemical Formula 9]

[0109] Next, the following composition F1 was coated onto the photoalignment film 1 using a rod coater. The coating formed on the photoalignment film 1 was heated to 125°C using warm air, then cooled to 60°C, and then subjected to a high-pressure mercury lamp at a wavelength of 365 nm under a nitrogen atmosphere at a concentration of 200 mJ / cm². 2 The coating was irradiated with ultraviolet light, and then heated to 120°C while simultaneously applying 200 mJ / cm² of UV radiation. 2Ultraviolet light irradiates the coating, thereby fixing the orientation of the liquid crystal compound and creating an optically anisotropic layer A1, which serves as the positive A plate. In addition, the thickness of the optical anisotropic layer A1 is 2.8 μm.

[0110] ─────────────────────────────── Composition F1 ─────────────────────────────── • 45.36 parts by weight of the following polymerizable liquid crystal compound LA-1 • 21.84 parts by weight of the following polymerizable liquid crystal compound LA-2 • 20.00 parts by weight of the following polymerizable liquid crystal compound LA-3 • 5.00 parts by weight of the following polymerizable liquid crystal compound LA-4 • 7.80 parts by weight of the following mixture of polymerizable liquid crystal compounds, LA-5 • 0.50 parts by weight of the following polymerization initiator PI-1 • 0.09 parts by weight of the following leveling agent T-1 · Cyclopentanone 180.73 parts by weight 53.98 parts by weight of methyl ethyl ketone ───────────────────────────────

[0111] Polymerizable liquid crystal compound LA-1 (tBu represents tert-butyl).

[0112] [Chemical Formula 10]

[0113] Polymerized liquid crystal compound LA-2

[0114] [Chemical Formula 11]

[0115] Polymerized liquid crystal compound LA-3

[0116] [Chemical Formula 12]

[0117] The polymerizable liquid crystal compound LA-4 (Me represents methyl).

[0118] [Chemical Formula 13]

[0119] LA-5 is a mixture of polymerizable liquid crystal compounds (a mixture of the following liquid crystal compounds (RA), (RB), and (RC) in a mass ratio of 84:14:2).

[0120] [Chemical Formula 14]

[0121] Polymerization initiator PI-1

[0122] [Chemical Formula 15]

[0123] Leveling agent T-1 [In the following formula, the value recorded in each repeating unit represents the content (mass%) of each repeat relative to all repeating units. Weight-average molecular weight: 25000]

[0124] [Chemical Formula 16]

[0125] <Polarizer> Next, an 80 μm thick polyvinyl alcohol film was dyed by immersing it in a 0.05% (w / w) iodine aqueous solution at 30°C for 60 seconds. Then, the resulting film was longitudinally stretched to five times its original length during immersion in a 4% (w / w) boric acid aqueous solution for 60 seconds, and then dried at 50°C for 4 minutes to obtain a polarizer with a thickness of 20 μm.

[0126] <The Making of an Image Display Device> An adhesive layer is formed by coating an adhesive (SK-2057, manufactured by Soken Chemical & Engineering Co., Ltd.) on the side of the optical anisotropic layer A1 obtained above, opposite to the side of the first dummy support. Then, the first dummy support 1 and the photo-alignment film 1 are peeled off after bonding the exposed surface of the optical anisotropic layer C1 in the transfer film 1 obtained above to the adhesive layer, thus obtaining a laminate. Next, an adhesive layer (SK-2057, manufactured by Soken Chemical & Engineering Co., Ltd.) is applied to one side of the obtained polarizer to form an adhesive layer. Using the above-described laminate, the optical anisotropy layer A1 in the laminate is bonded to the polarizer in such an orientation that the in-plane slow axis of the optical anisotropy layer A1 is at a 45° angle to the absorption axis of the polarizer. Furthermore, Corning Eagle XG glass is bonded to the optical anisotropy layer C1 side of the laminate using the adhesive (SK-2057, manufactured by Soken Chemical & Engineering Co., Ltd.) to obtain optical laminate 1. Furthermore, on the side of the optical laminate 1 opposite to the optical anisotropic layer C1 of the glass, an image display element is laminated using an adhesive (SK-2057, manufactured by Soken Chemical & Engineering Co., Ltd.) to obtain the image display device 1. The image display device 1 includes, from the visual recognition side, a polarizer, an optical anisotropic layer A1, an optical anisotropic layer C1, glass, and an image display element in sequence. In addition, it was confirmed that the glass does not affect the values ​​in equations (1) to (9).

[0127] [Comparative Examples 2-4] In Comparative Example 1, the thickness of the optical anisotropic layer C1 was changed to the value shown below, and otherwise, each image display device was obtained in the same manner as in Comparative Example 1. The thickness of the optical anisotropic layer C2 is 0.70 μm. The thickness of the optical anisotropic layer C3 is 0.87 μm. The thickness of the optical anisotropic layer C4 is 0.90 μm.

[0128] [Comparative Example 5] In Comparative Example 1, rod-shaped liquid crystal compound L-2 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass). Otherwise, the optical anisotropic layer C5 was fabricated using the same steps as in Comparative Example 1, and the image display device of Comparative Example 5 was obtained.

[0129] Rod-shaped liquid crystal compound L-2

[0130] [Chemical Formula 17]

[0131] [Comparative Example 6] Using the circular polarizer used in Comparative Example 30 of Japanese Patent Application Publication No. 2021-076826, CorningEagle XG glass was bonded to the C-plate side of the circular polarizer using an adhesive (SK-2057, manufactured by Soken Chemical & Engineering Co., Ltd.) to obtain an optical laminate. Furthermore, an image display element was laminated using a matching oil on the side of the glass in the obtained optical laminate opposite to the C-plate side, resulting in the image display device of Comparative Example 6.

[0132] [Comparative Example 7] Instead of the circular polarizer used in Comparative Example 30 of Japanese Patent Application Publication No. 2021-076826, the circular polarizer used in Example 17 of Japanese Patent Application Publication No. 2021-076826 was used, and the image display device of Comparative Example 7 was obtained by following the same steps as Comparative Example 6.

[0133] [Comparative Example 8] Instead of the circular polarizer used in Comparative Example 30 of Japanese Patent Application Publication No. 2021-076826, the circular polarizer used in Example 18 of Japanese Patent Application Publication No. 2021-076826 was used, and the image display device of Comparative Example 8 was obtained by following the same steps as Comparative Example 6.

[0134] [Comparative Example 9] Instead of the circular polarizer used in Comparative Example 30 of Japanese Patent Application Publication No. 2021-076826, the circular polarizer used in Example 19 of Japanese Patent Application Publication No. 2021-076826 was used, and the image display device of Comparative Example 9 was obtained by following the same steps as Comparative Example 6.

[0135] [Example 1] In Comparative Example 1, a mixture of rod-shaped liquid crystal compounds L-3 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 below. Otherwise, the optical anisotropic layer C10 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 1 was obtained.

[0136] L-3, a mixture of rod-shaped liquid crystal compounds

[0137] [Chemical Formula 18]

[0138] [Example 2] In Comparative Example 1, rod-shaped liquid crystal compound L-4 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 below. Otherwise, the optical anisotropic layer C11 was fabricated using the same steps as in Comparative Example 1, and the image display element of Example 2 was obtained.

[0139] Rod-shaped liquid crystal compound L-4

[0140] [Chemical Formula 19]

[0141] [Example 3] In Comparative Example 1, rod-shaped liquid crystal compound L-5 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 described later. Otherwise, the optical anisotropic layer C12 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 3 was obtained.

[0142] Rod-shaped liquid crystal compound L-5

[0143] [Chemical Formula 20]

[0144] [Example 4] In Comparative Example 1, rod-shaped liquid crystal compound L-5 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 described later. Otherwise, the optical anisotropic layer C13 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 4 was obtained.

[0145] [Example 5] In Comparative Example 1, rod-shaped liquid crystal compound L-5 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 described later. Otherwise, the optical anisotropic layer C14 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 5 was obtained.

[0146] [Example 6] In Comparative Example 1, rod-shaped liquid crystal compound L-6 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass), and the film thickness of the optical anisotropic layer was adjusted in a manner to obtain the phase difference shown in Table 1 described later. Otherwise, the optical anisotropic layer C15 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 6 was obtained.

[0147] Rod-shaped liquid crystal compound L-6

[0148] [Chemical Formula 21]

[0149] [Measurement] <Values ​​related to the phase difference layer> Using Axometrics' Axoscan, the values ​​related to the phase difference layer, A plate, and C plate shown in the table below were measured using the methods described above.

[0150] <Values ​​related to image display elements> A sample for measurement was obtained by stacking fused silica on the surface of an image display element with a refractive index matching oil layer. Furthermore, when each image display device is fabricated using an image display element of the object to be measured, the first or third direction in the measurement of values ​​related to the image display element is the direction from which the measurement light is incident, corresponding to the first or third direction of the phase retardation layer. Using a reflectance ellipsometry RC2 (manufactured by JAWoollam), the values ​​related to the image display elements shown in the table below were measured for the samples used in the above measurements.

[0151] [Tonal difference] For each image display device produced, the tonal difference was evaluated under bright light. With the image display device set to OFF (black state), the reflected light from the fluorescent lamp was observed from three directions: the front (visual recognition side), a direction parallel to the in-plane fast axis of the phasing layer at a polar angle of 45°, and a direction parallel to the in-plane slow axis of the phasing layer at a polar angle of 45°. Compared to the front view, the display quality at a polar angle of 45° was evaluated according to the following criteria. “A”: No visual difference in tone was detected. “B”: A very slight difference in hue that can be visually detected. "C": Although there is a noticeable difference in color tone, there are no problems with its use. "D": Visually recognizable color difference, unacceptable.

[0152] [Reflection Intensity] In the [hue difference] category, the intensity of the reflected light was evaluated according to the following criteria when the reflected light was observed from all directions at a polar angle of 45°. “A”: The reflected light is weak and acceptable. "B": The reflected light intensity is unacceptable.

[0153] [Table 1]

[0154] [Table 2]

[0155] [Table 3]

[0156] Based on the evaluation results shown in Table 3, it is confirmed that if this is the present invention, the color difference is small. The comparison of Examples 1 to 6 confirms that the present invention is more effective when the image display device satisfies the relationship of Equation (3-1), the relationship of Equation (6-1), and the relationship of Equation (9-1).

[0157] [Examples 7-9] In Comparative Example 1, rod-shaped liquid crystal compound L-7 (100 parts by mass) was used instead of rod-shaped liquid crystal compound L-1 (100 parts by mass) to adjust the film thickness of the optical anisotropy layer in order to obtain the phase difference shown in Table 4 below. Glass was laminated on the non-glossy side of commercially available aluminum foil instead of an image display element. Otherwise, the optical anisotropy layer C18 was fabricated using the same steps as in Comparative Example 1, and the image display device of Example 7 was obtained. The image display element of Embodiment 7 comprises, from the visual recognition side, a polarizer, an optical anisotropic layer A1, an optical anisotropic layer C1, glass, and aluminum foil. In addition, the non-glossy surface of the aluminum foil was used as the measurement surface to measure the aforementioned Rf. 450 (45) M et al.

[0158] Rod-shaped liquid crystal compound L-7

[0159] [Chemical Formula 22]

[0160] [Table 4]

[0161] [Table 5]

[0162] [Table 6]

[0163] As shown in Table 6 above, it was confirmed that the desired effects could also be obtained in the above embodiments 7 to 9. Furthermore, while aluminum foil was used in these embodiments, the same effects as described above could be obtained even when using an image display element that displays reflectivity similar to aluminum foil. Symbol Explanation

[0164] 10 - Image display device; 20 - Polarizer; 30 - Phase retardation layer; 40 - Image display element; AA - Absorption axis of polarizer; SA - In-plane slow axis of phase retardation layer; FA - In-plane fast axis of phase retardation layer; 50 - First direction; 51 - Second direction; 60 - Second or fourth surface.

Claims

1. An image display device, comprising, in sequence, a polarizer, a phase difference layer, and an image display element, wherein, The angle between the absorption axis of the polarizer and the in-plane slow axis of the phase difference layer is 45±5°. The image display device satisfies the relationships of equations (1) to (9). Equation (1) α 450 =R 450 (0) - {Rf 450 (45) + (Rf 450 (45)M / 2)} Equation (2) β 450 =R 450 (0) - {Rs 450 (45) - (Rs 450 (45)M / 2)} formula (3) |a 450 |+|b 450 |≤4.0nm Formula (4) α 550 =R 550 (0) - {Rf 550 (45) + (Rf 550 (45)M / 2)} Equation (5) β 550 =R 550 (0) - {Rs 550 (45) - (Rs 550 (45)M / 2)} formula (6) |a 550 |+|b 550 |≤4.1nm Equation (7) α 650 =R 650 (0) - {Rf 650 (45) + (Rf 650 (45) M / 2)} Equation (8) β 650 =R 650 (0) - {Rs 650 (45) - (Rs 650 (45)M / 2)} formula (9) |a 650 |+|b 650 |≤4.0nm R 450 (0) indicates the in-plane delay of the phase retardation layer at a wavelength of 450 nm. Rf 450 (45) represents the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the first direction, which is tilted at a polar angle of 45° relative to the normal direction of the surface of the phase difference layer with the in-plane fast axis of the phase difference layer as the rotation axis. Rf 450 (45) M represents the phase difference at a wavelength of 450 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element from the first direction. When measuring the phase difference at a wavelength of 450 nm, the surface containing the normal direction of the first direction and the surface of the image display element is designated as the first surface. The direction with a polar angle of 45° relative to the normal direction of the surface of the image display element in an azimuth angle 180° away from the first direction is designated as the second direction. When the surface with the second direction as its normal direction is designated as the second surface, and the slow axis is represented in the direction parallel to the first surface, Rf... 450 (45) The value of the phase difference represented by M is a positive value, and in the second plane, when the slow axis is represented in the direction orthogonal to the first plane, it is represented by Rf. 450 (45) The value of the phase difference represented by M is indicated by a negative value. Rs 450 (45) represents the phase difference of the phase difference layer at a wavelength of 450 nm, measured from the third direction, which is tilted at a polar angle of 45° relative to the normal direction of the surface of the phase difference layer with the in-plane slow axis of the phase difference layer as the axis of rotation. Rs 450 (45) M represents the phase difference at a wavelength of 450 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element in the third direction. When measuring the phase difference at a wavelength of 450 nm, the surface containing the normal direction of the third direction and the surface of the image display element is designated as the third surface. The direction with a polar angle of 45° relative to the normal direction of the surface of the image display element in an azimuth angle deviating 180° from the third direction is designated as the fourth direction. When the surface with the fourth direction as its normal direction is designated as the fourth surface, and the slow axis is represented in the direction parallel to the third surface, Rs... 450 (45) The value of the phase difference represented by M is a positive value, and in the fourth plane, in the case of representing the slow axis in the direction orthogonal to the third plane, it is represented by Rs. 450 (45) The value of the phase difference represented by M is indicated by a negative value. R 550 (0) indicates the in-plane delay of the phase retardation layer at a wavelength of 550 nm. Rf 550 (45) represents the phase difference of the phase difference layer at a wavelength of 550 nm, measured from the first direction. Rs 550 (45) represents the phase difference of the phase difference layer at a wavelength of 550 nm, measured from the third direction. Rf 550 (45) M represents the phase difference at a wavelength of 550 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element in the first direction, and the measured light and the reflected light. When measuring the phase difference at a wavelength of 550 nm, in the second surface, where the slow axis is represented in the direction parallel to the first surface, Rf... 550 (45) The value of the phase difference represented by M is a positive value, and in the second plane, when the slow axis is represented in the direction orthogonal to the first plane, it is represented by Rf. 550 (45) The value of the phase difference represented by M is indicated by a negative value. Rs 550 (45) M represents the phase difference at a wavelength of 550 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element in the third direction. When measuring the phase difference at a wavelength of 550 nm, in the fourth plane, where the slow axis is represented in the direction parallel to the third plane, Rs... 550 (45) The value of the phase difference represented by M is a positive value, and in the fourth plane, in the case of representing the slow axis in the direction orthogonal to the third plane, it is represented by Rs. 550 (45) The value of the phase difference represented by M is indicated by a negative value. R 650 (0) indicates the in-plane delay of the phase retardation layer at a wavelength of 650 nm. Rf 650 (45) represents the phase difference of the phase difference layer at a wavelength of 650 nm, measured from the first direction. Rs 650 (45) represents the phase difference of the phase difference layer at a wavelength of 650 nm, measured from the third direction. Rf 650 (45) M represents the phase difference at a wavelength of 650 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element in the first direction, and the measured light and the reflected light. When measuring the phase difference at a wavelength of 650 nm, in the second surface, where the slow axis is represented in the direction parallel to the first surface, Rf... 650 (45) The value of the phase difference represented by M is a positive value, and in the second plane, when the slow axis is represented in the direction orthogonal to the first plane, it is represented by Rf. 650 (45) The value of the phase difference represented by M is indicated by a negative value. Rs 650 (45) M represents the phase difference at a wavelength of 650 nm calculated based on the change in polarization state of the measured light and the reflected light received from the image display element in the third direction. When measuring the phase difference at a wavelength of 650 nm, in the fourth plane, where the slow axis is represented in the direction parallel to the third plane, Rs... 650 (45) The value of the phase difference represented by M is a positive value, and in the fourth plane, in the case of representing the slow axis in the direction orthogonal to the third plane, it is represented by Rs. 650 (45) The value of the phase difference represented by M is represented by a negative value.

2. The image display device according to claim 1, wherein, Rf 450 (45) M and Rs 450 (45) M is all between -25 and -5 nm. Rf 550 (45) M and Rs 550 (45) M is all between -15 and 5 nm. Rf 650 (45) M and Rs 650 (45) M is -10 to 10 nm.

3. The image display device according to claim 1 or 2, wherein, It also satisfies the relationships in equation (3-1), equation (6-1), and equation (9-1). Equation (3-1) 0nm ≤ |α 450 | + |β 450 | ≤ 3.5nm Equation (6-1) 0nm ≤ |α 550 | + |β 550 | ≤ 3.5nm Equation (9-1) 0 nm ≤ |α 650 | + |β 650 | ≤ 3.5 nm.

4. The image display device according to claim 1 or 2, wherein, The phase difference layer has an A plate and a C plate.

Images