Arrangement structure of optical components and display body

Abstract

Adjusting the light emitted from the display surface at an oblique angle. [Solution] An arrangement structure for optical members provided on a display body that displays an image to a user, comprising a first polarizing member, an adjustment member, and a second polarizing member, wherein the first polarizing member, the adjustment member, and the second polarizing member are arranged in this order toward the user, the adjustment member includes a λ / 2 member, and when the second polarizing member is viewed from the user side, the transmission axis of the second polarizing member and the transmission axis of the first polarizing member are substantially orthogonal, and the transmission axis of the second polarizing member and the lagging axis of the λ / 2 member form an angle of 40° to 50°.

Description

Technical Field

[0001] The present invention relates to an arrangement structure of optical members and a display body.

Background Art

[0002] In image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), in order to realize image display and improve the performance of image display, generally, optical members such as polarizing members and retardation members are used (see, for example, Patent Document 1).

[0003] In recent years, as a new application of image display devices, near-eye displays typified by, for example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) have been proposed.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Light representing an image can be emitted not only in the front direction but also in an oblique direction from the display surface of an image display device, and the light emitted in this oblique direction may cause problems in the use of the image display device. For example, there is a problem that an image can be seen by a person other than the user of the image display device. Also, for example, in a near-eye display, there is a problem that light emitted in an oblique direction from the display surface of a display element is reflected by the end of a lens or the inner wall of a housing included in the near-eye display, causing stray light.

[0006] In view of the above, an object of the present invention is to adjust light emitted in an oblique direction from a display surface. [Means for solving the problem]

[0007] 1. An optical member arrangement structure according to an embodiment of the present invention is an optical member arrangement structure provided on a display body that displays an image to a user, comprising a first polarizing member, an adjustment member, and a second polarizing member, wherein the first polarizing member, the adjustment member, and the second polarizing member are arranged in this order toward the user, the adjustment member includes a λ / 2 member, and when the second polarizing member is viewed from the user side, the transmission axis of the second polarizing member and the transmission axis of the first polarizing member are substantially orthogonal, and the transmission axis of the second polarizing member and the lagging axis of the λ / 2 member form an angle of 40° to 50°. 2. In the optical member arrangement structure described in paragraph 1 above, the ratio of the transmittance of the optical laminate in the oblique direction to the transmittance in the front direction of the optical laminate in which the first polarizing member, the adjusting member, and the second polarizing member are stacked in this order may be 0.85 or less. 3. In the optical component arrangement structure described in 1 or 2 above, the transmittance in the oblique direction of the optical laminate in which the first polarizing member, the adjusting member, and the second polarizing member are stacked in this order may be 30% or less. 4. In the arrangement structure of optical members described in any of items 1 to 3 above, the absolute value of the phase difference Rth(550) in the thickness direction of the adjustment member may be 500 nm or more. 5. In the arrangement structure of optical elements described in item 4 above, the Nz coefficient of the λ / 2 element may be 2.0 or greater. 6. In the arrangement structure of the optical members described in item 4 above, the adjustment member may further include a member that provides a phase difference in the thickness direction, and the absolute value of the phase difference Rth(550) in the thickness direction of the member that provides a phase difference in the thickness direction may be 300 nm or more and 1000 nm or less. 7. An embodiment of the present invention is a display having the arrangement structure of optical members described in any of 1 to 6 above, wherein the display comprises a liquid crystal display or an organic EL display. 8. Another embodiment of the present invention is a display having the arrangement structure of optical members described in any of 1 to 6 above, wherein the display is a near-eye display. [Effects of the Invention]

[0008] According to the optical member arrangement structure of the embodiment of the present invention, the problem caused by light emitted obliquely from the display surface can be solved. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram showing the general configuration of a display body according to one embodiment of the present invention. [Figure 2] This is a schematic diagram showing the general configuration of an example of a display system included in a near-eye display. [Figure 3] This is a schematic diagram showing the general configuration of a display system included in a display body according to another embodiment of the present invention. [Figure 4] This is a schematic diagram showing the general configuration of a display system included in a display body according to yet another embodiment of the present invention. [Figure 5] This is a schematic perspective view showing an example of a multilayer structure contained in a reflective polarizing film. [Figure 6] This graph shows the results of transmittance measurements at an azimuth angle of 0°. [Figure 7] This graph shows the results of transmittance measurements at an azimuth angle of 45°. [Figure 8] This graph shows the results of transmittance measurements at an azimuth angle of 90°. [Figure 9] This graph shows the results of transmittance measurements at an azimuth angle of 135°. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. The drawings may schematically represent the width, thickness, shape, etc. of each part compared to the embodiments for clearer explanation, but this is merely an example and does not limit the interpretation of the present invention. Also, for the drawings, the same or equivalent elements may be denoted by the same reference numerals, and redundant explanations may be omitted.

[0011] (Definitions of Terms and Symbols) The definitions of terms and symbols in this specification are as follows. (1) Refractive Index (nx, ny, nz) “nx” is the refractive index in the direction where the in-plane refractive index is maximum (i.e., the slow axis direction), “ny” is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and “nz” is the refractive index in the thickness direction. (2) In-Plane Phase Difference (Re) “Re(λ)” is the in-plane phase difference measured with light of wavelength λ nm at 23°C. For example, “Re(550)” is the in-plane phase difference measured with light of wavelength 550 nm at 23°C. Re(λ) is obtained by the formula: Re(λ) = (nx - ny) × d when the thickness of the layer (film) is d (nm). (3) Phase Difference in the Thickness Direction (Rth) “Rth(λ)” is the phase difference in the thickness direction measured with light of wavelength λ nm at 23°C. For example, “Rth(550)” is the phase difference in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) is obtained by the formula: Rth(λ) = (nx - nz) × d when the thickness of the layer (film) is d (nm). (4) Nz Coefficient The Nz coefficient is obtained by Nz = Rth / Re. (5) Angle When referring to an angle in this specification, unless otherwise specified, the angle encompasses both clockwise and counterclockwise directions with respect to the reference direction. Therefore, for example, "45°" means ±45°. Also, in this specification, "substantially parallel" encompasses a range of 0° ± 10°, preferably within a range of 0° ± 5°, more preferably within a range of 0° ± 3°, and even more preferably within a range of 0° ± 1°. "Substantially orthogonal" encompasses a range of 90° ± 10°, preferably within a range of 90° ± 5°, more preferably within a range of 90° ± 3°, and even more preferably within a range of 90° ± 1°.

[0012] FIG. 1 is a schematic diagram showing a general configuration of a display body according to one embodiment of the present invention. The display body 100 includes a display element 12. The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. The light emitted from the display surface 12a passes through, for example, a first polarizing member 31 included in the display element 12 and is emitted as linearly polarized light.

[0013] On the display body 100, an adjustment member 30 and a second polarizing member 32 are provided on the display surface 12a side of the display element 12. The first polarizing member 31, the adjustment member 30, and the second polarizing member 32 included in the display element 12 constitute an arrangement structure 1 of optical members. The linearly polarized light emitted through the first polarizing member 31 can enter the user's eye 3 through the adjustment member 30 and the second polarizing member 32. The first polarizing member 31, the adjustment member 30, and the second polarizing member 32 are arranged in this order toward the user. Note that in FIG. 1, details of the configuration of the display element 12 are omitted. Also, although the first polarizing member 31 is located on the outermost surface of the display element 12, as long as the effects of the present invention can be obtained, other members may be provided on the surface of the first polarizing member 31.

[0014] The first polarizing member 31 and the second polarizing member 32 included in the display element 12 may be arranged such that, for example, when the second polarizing member 32 is viewed from the user's side, the transmission axis of the second polarizing member 32 and the transmission axis of the first polarizing member 31 are substantially orthogonal. Furthermore, it is preferable that the adjustment member 30 includes a λ / 2 member. The in-plane phase difference Re(550) of the λ / 2 member is, for example, 200 nm to 330 nm, but may also be 230 nm to 330 nm, 230 nm to 300 nm, or 250 nm to 290 nm. When the second polarizing member 32 is viewed from the user's side, the angle between the transmission axis of the second polarizing member 32 and the lagging axis of the λ / 2 member included in the adjustment member 30 is, for example, 40° to 50°, but may also be 42° to 48°, or approximately 45°.

[0015] The formation of the optical component arrangement structure 1 can solve problems caused by light emitted obliquely from the display surface 12a. For example, the problem of images being seen by people other than the user can be solved. The ratio of the oblique transmittance of the optical laminate, in which the first polarizing member 31, the adjusting member 30, and the second polarizing member 32 are stacked in this order, to the transmittance in the front direction is preferably 0.85 or less, more preferably 0.75 or less, and even more preferably 0.50 or less. The transmittance in the front direction of the optical laminate, in which the first polarizing member 31, the adjusting member 30, and the second polarizing member 32 are stacked in this order, is preferably 35% or more. The transmittance in the oblique direction of the optical laminate, in which the first polarizing member 31, the adjusting member 30, and the second polarizing member 32 are stacked in this order, is preferably 30% or less.

[0016] The first polarizing member 31, the adjusting member 30, and the second polarizing member 32 constituting the optical member arrangement structure 1 may be partially or entirely integrated. The integration of the optical members can be performed using any suitable adhesive layer. The adhesive layer may be formed of an adhesive or a tack. Specifically, the adhesive layer may be an adhesive layer or a tack layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

[0017] The first polarizing member and the second polarizing member constituting the arrangement structure of the optical member according to the embodiment of the present invention may each be an absorptive polarizing member or a reflective polarizing member. As shown in the illustrated example, the first polarizing member 31 included in the display element 12 may typically be an absorptive polarizing member. The second polarizing member 32 is preferably an absorptive polarizing member. The absorptive polarizing member typically includes a resin film containing a dichroic substance (sometimes referred to as an absorptive polarizing film). The absorptive polarizing member may, for example, include a protective layer for the absorptive polarizing film. The adjustment member 30 may also function as a protective layer for the absorptive polarizing film.

[0018] The thickness of the absorption polarizing film is, for example, 1 μm or more and 20 μm or less, but may also be 2 μm or more and 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less.

[0019] The above-mentioned absorption polarizing film may be made from a single layer of resin film, or it may be made using a laminate of two or more layers.

[0020] When manufactured from a single layer of resin film, for example, an absorption polarizing film can be obtained by subjecting a hydrophilic polymer film, such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene-vinyl acetate copolymer film, to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment. Among these, an absorption polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0021] The above iodine staining is carried out, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio for the above uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the staining treatment, or during the staining process. Alternatively, staining may be performed after stretching. If necessary, the PVA-based film may be subjected to swelling, crosslinking, washing, drying, etc.

[0022] When using the above-mentioned laminate of two or more layers, examples of laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate. An absorption polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of a resin substrate and a PVA-based resin layer; or by stretching and dyeing the laminate to make the PVA-based resin layer an absorption polarizing film. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes applying an air-assisted stretching treatment, a dyeing treatment, a water-based stretching treatment, and a drying shrinkage treatment to the laminate in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated on a thermoplastic resin, making it possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA and dissolution when immersed in water in the subsequent dyeing and stretching processes, making it possible to achieve high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. As a result, the optical properties of the absorption polarizing film obtained through processing steps in which the laminate is immersed in a liquid, such as dyeing and water-based stretching, can be improved. Furthermore, by shrinking the laminate in the width direction through a drying shrinkage treatment, the optical properties can be improved.The resulting resin substrate / absorbent polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorbent polarizing film), or an appropriate protective layer may be laminated on the peeled surface obtained by removing the resin substrate from the resin substrate / absorbent polarizing film laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of such a method for manufacturing an absorbent polarizing film are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0023] The orthogonal transmittance (Tc) of the absorbing polarizing film (absorbing polarizing member) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single-layer transmittance (Ts) of the absorbing polarizing film (absorbing polarizing member) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorbing polarizing film (absorbing polarizing member) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0024] The adjustment member 30 has an absolute value of the phase difference Rth(550) in the thickness direction that is, for example, 300 nm or more and 1200 nm or less, preferably 500 nm or more, more preferably 600 nm or more, even more preferably 800 nm or more, and particularly preferably 1000 nm or more. By using such an adjustment member 30, for example, the transmittance of the optical laminate can be improved.

[0025] For example, the adjustment member 30 may be a λ / 2 member having refractive index characteristics nx>ny>nz. In this case, the Nz coefficient of the λ / 2 member may be greater than 1 and less than or equal to 6.0, preferably 2.0 or more, more preferably 2.5 or more, even more preferably 3.0 or more, and particularly preferably 3.5 or more. In one embodiment, the λ / 2 member having refractive index characteristics nx>ny>nz may be a laminate of multiple members (negative B plates) having refractive index characteristics nx>ny>nz. The λ / 2 member (negative B plate) having refractive index characteristics nx>ny>nz may exhibit inverse dispersion wavelength characteristics, positive wavelength dispersion characteristics, or flat wavelength dispersion characteristics.

[0026] A λ / 2 member (negative B plate) having the refractive index characteristics nx>ny>nz can be made of any suitable material that satisfies the above characteristics. For example, a λ / 2 member (negative B plate) having the refractive index characteristics nx>ny>nz can be made of a stretched resin film. Examples of resins included in the resin film include cycloolefin resins (e.g., norbornene resins), polycarbonate resins, cellulose resins, polyvinyl alcohol resins, polysulfone resins, etc. Such resins can be used alone or in combination. The above resin film preferably contains norbornene resin and / or cellulose resin. Details of these resins and methods for stretching resin films are described, for example, in Japanese Patent Application Publication No. 2018-205485. The description in this publication is incorporated herein by reference.

[0027] When a λ / 2 member having refractive index characteristics nx>ny>nz is constructed using multiple negative B plates, the thickness of a single negative B plate may be, for example, 10 μm to 80 μm, or 15 μm to 60 μm.

[0028] For example, in addition to the λ / 2 member, the adjustment member 30 may include a member that provides a phase difference in the thickness direction. In this case, the λ / 2 member preferably exhibits a refractive index characteristic of nx > ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range that does not impair the effects of the present invention, ny < nz may occur. The Nz coefficient of the λ / 2 member having a refractive index characteristic of nx > ny ≧ nz is, for example, 0.9 to 2.0, preferably 0.9 to 1.5, and more preferably 0.9 to 1.3. The λ / 2 member having a refractive index characteristic of nx > ny ≧ nz may exhibit an inverse dispersion wavelength characteristic, a positive wavelength dispersion characteristic, or a flat wavelength dispersion characteristic.

[0029] The member that provides the phase difference in the thickness direction may be, for example, a member (so-called positive C-plate) having a refractive index characteristic of nz > nx = ny, or a member (so-called negative C-plate) having a refractive index characteristic of nx = ny > nz, or a combination thereof. Here, "nx = ny" includes not only the case where nx and ny are exactly equal but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the member that provides the phase difference in the thickness direction is, for example, less than 10 nm.

[0030] The absolute value of the thickness-direction phase difference Rth(550) of the member that provides the phase difference in the thickness direction is preferably 300 nm or more and 1000 nm or less, more preferably 400 nm or more, and even more preferably 500 nm or more. In one embodiment, the member that provides the phase difference in the thickness direction may be a laminate of a plurality of positive C-plates or a laminate of a plurality of negative C-plates.

[0031] The positive C-plate is formed of any suitable material. The positive C-plate may be, for example, a resin film or an alignment cured layer of a liquid crystal compound.

[0032] Typical materials for the resin film constituting the positive C plate include resin materials having negative birefringence. Resins having negative birefringence are resins that exhibit the property of having the maximum refractive index in the direction perpendicular to the stretching direction when uniaxially stretched. Examples of resins having negative birefringence include resins in which chemical bonds or functional groups with high polarization anisotropy, such as aromatic rings or carbonyl groups, are introduced into the side chains. Specific examples of resins having negative birefringence include acrylic resins, styrene resins, maleimide resins, modified polyolefin resins, and fumarate ester resins. For specific examples, refer to the resins having negative birefringence described in Japanese Patent Publication No. 2021-076759, Japanese Patent Publication No. 2008-544304, Japanese Patent Publication No. 2008-544317, etc. The above resin materials can be used individually or in combination of two or more types.

[0033] The resin film constituting the positive C plate may further contain any suitable additives as needed. Specific examples of additives include plasticizers, heat stabilizers, light stabilizers, lubricants, antioxidants, UV absorbers, flame retardants, colorants, antistatic agents, compatibilizers, crosslinking agents, and thickeners. The type and content of additives may be appropriately determined depending on the purpose. The additive content in the resin film is, for example, about 3% to 10% by weight.

[0034] In one embodiment, the resin material can be used as a positive C plate after being formed into a film. Specifically, the formed film can be used as a positive C plate without stretching. For example, when a resin solution containing the resin material is applied to a support (by a solution film formation method), stress is generated due to volume shrinkage when the resin solution dries on the support, causing the polymer molecular chains to tend to orient in the in-plane direction. By using a resin material with high birefringence and negative intrinsic birefringence, a coating with large thickness-direction birefringence can be formed on the support due to shrinkage during drying. The formed coating can then be used as a positive C plate.

[0035] The thickness of the positive C plate, which is made of resin film, is, for example, 1 μm to 40 μm, and may also be 3 μm to 35 μm, or 5 μm to 30 μm.

[0036] As the orientation solidification layer of the liquid crystal compound constituting the positive C plate, a preferred example is an orientation solidification layer of a liquid crystal material fixed in a homeotropic orientation. The liquid crystal material (liquid crystal compound) that can be homeotropically oriented may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of methods for forming such liquid crystal compounds and positive C plates include the liquid crystal compound and the method for forming the phase difference layer described in paragraphs

[0020] to

[0028] of Japanese Patent Application Publication No. 2002-333642.

[0037] The thickness of the positive C plate, which is composed of an oriented solidified layer of liquid crystal compound, is, for example, 0.5 μm to 10 μm, and may be 0.5 μm to 8 μm, or 0.5 μm to 5 μm.

[0038] The negative C plate is formed from any suitable material. Preferably, the negative C plate is a resin film.

[0039] Typical materials for the resin film constituting a negative C plate include resin materials with positive birefringence. The negative C plate may be a stretched film or an unstretched film. For example, a negative C plate may be composed of a cellulose-based resin.

[0040] The above-mentioned cellulose-based resin is not particularly limited, but is preferably a cellulose organic acid ester or cellulose mixed organic acid ester in which some or all of the hydroxyl groups of cellulose are substituted with acetyl groups, propionyl groups and / or butyl groups. Examples of cellulose organic acid esters include cellulose acetate, cellulose propionate, and cellulose butyrate. Examples of cellulose mixed organic acid esters include cellulose acetate propionate and cellulose acetate butyrate. The above-mentioned cellulose-based resin is described, for example, in Japanese Patent Application Publication No. 2001-188128

[0040] ~

[0041] It can be obtained by the method described above.

[0041] The degree of substitution in cellulosic resins (the number of hydroxyl groups substituted on the carbon atoms at positions 2, 3, and 6 in the cellulose backbone) is not particularly limited. The degree of acetyl substitution can be determined by ASTM-D817-91 (Test method for cellulose acetate, etc.). The degree of propionyl substitution can be determined by ASTM-D817-96 (Test method for cellulose acetate, etc.).

[0042] The weight-average molecular weight (Mw) of the cellulose resin, as measured by gel permeation chromatography (GPC) using tetrahydrofuran solvent, is preferably 20,000 to 1,000,000, and more preferably 25,000 to 800,000. The glass transition temperature (Tg) of the cellulose resin is preferably 110°C to 185°C. If Tg is 110°C or higher, a film with good thermal stability is more likely to be obtained, and if it is 185°C or lower, excellent moldability is obtained. The glass transition temperature (Tg) can be determined by the DSC method in accordance with JIS K 7121:1987.

[0043] Negative C plates composed of cellulose resin can be obtained by any suitable molding method. Preferably, negative C plates composed of cellulose resin are made by stretching a polymer film, which has been formed into a sheet by solvent casting or melt extrusion, using a transverse uniaxial stretching method, a longitudinal and transverse simultaneous biaxial stretching method, or a longitudinal and transverse sequential biaxial stretching method. The stretching temperature of the polymer film is preferably 120°C to 200°C. The stretching ratio of the polymer film is preferably greater than 1 and less than or equal to 3 times. As for negative C plates composed of cellulose resin, commercially available films can be used as is. In addition, as negative C plates composed of cellulose resin, films that have undergone secondary processing such as stretching and / or shrinking treatment can also be used.

[0044] The thickness of the negative C plate, which is made of cellulose resin, is, for example, 10 μm to 105 μm, but may also be 15 μm to 100 μm, or 20 μm to 95 μm.

[0045] For example, the negative C plate may be made of a polyimide resin. When polyimide resin is formed into a sheet by the solvent casting method, the molecules tend to spontaneously orient during the evaporation process of the solvent, making it possible to produce very thin members that exhibit the relationship nx=ny>nz in refractive index properties. The negative C plate may be obtained by stretching the film formed by the solvent casting method using a longitudinal uniaxial stretching method or a transverse uniaxial stretching method. The stretching temperature of the film is preferably 120°C to 200°C. The stretching ratio of the film is preferably greater than 1 and less than or equal to 3 times. The thickness of the negative C plate made of polyimide resin may be 0.5 μm to 10 μm, or 1 μm to 5 μm.

[0046] Preferably, the polyimide resin has a hexafluoroisopropylidene group and / or a trifluoromethyl group. More preferably, the polyimide resin has at least a repeating unit represented by the following general formula (I) or a repeating unit represented by the following general formula (II). Polyimide resins containing these repeating units have excellent solubility in general solvents, making it possible to form films by the solvent casting method. Furthermore, a thin layer of the polyimide resin can be formed on substrates with poor solvent resistance, such as triacetylcellulose films, without excessively eroding the surface. [ka] [ka]

[0047] In the above general formulas (I) and (II), G and G' represent groups independently selected from the group consisting of a covalent bond, a CH2 group, two C(CH3) groups, two C(CF3) groups, two C(CX3) groups (where X is a halogen), a CO group, an O atom, an S atom, an SO2 group, two Si(CH2CH3) groups, and an N(CH3) group, and they may be the same or different.

[0048] In the general formula (I) above, L is a substituent, and e represents the number of substitutions. L can be, for example, a halogen, a C1-C3 alkyl group, a C1-C3 halogenated alkyl group, a phenyl group, or a substituted phenyl group. If there are multiple Ls, they may be the same or different. e is an integer from 0 to 3.

[0049] In the above general formula (II), Q is a substituent, and f represents the number of substitutions. For example, Q is an atom or group selected from the group consisting of hydrogen, halogen, alkyl group, substituted alkyl group, nitro group, cyano group, thioalkyl group, alkoxy group, aryl group, substituted aryl group, alkyl ester group, and substituted alkyl ester group. If there are multiple Qs, they may be the same or different. f is an integer from 0 to 4, and g and h are integers from 1 to 3, respectively.

[0050] The above polyimide resins can be obtained, for example, by the reaction of a tetracarboxylic dianhydride with a diamine. The repeating unit of general formula (I) can be obtained, for example, by using 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl as the diamine and reacting it with a tetracarboxylic dianhydride having at least two aromatic rings. The repeating unit of general formula (II) can be obtained, for example, by using 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanoic acid dianhydride as the tetracarboxylic dianhydride and reacting it with a diamine having at least two aromatic rings. The above reactions may be, for example, chemical imidation proceeding in two steps, or thermal imidation proceeding in one step.

[0051] Examples of the above tetracarboxylic dianhydrides include 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanoic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, 2,3,3',4-benzophenonetetracarboxylic acid dianhydride, 2,2',3,3'-benzophenonetetracarboxylic acid dianhydride, 2,2'-dibromo-4,4',5,5'-biphenyltetracarboxylic acid dianhydride, and 2,2'-bis(trifluoromethyl Examples include 4,4',5,5'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenyl) ether dianhydride, 4,4'-oxydiphthalic acid dianhydride, 4,4'-bis(3,4-dicarboxyphenyl)sulfonic acid dianhydride, bis(2,3-dicarboxyphenyl)methaneic acid dianhydride, and bis(3,4-dicarboxyphenyl)diethylsilaneic acid dianhydride.

[0052] Examples of the above-mentioned diamines include 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-diaminobiphenyl, 4,4'-diaminophenylmethane, 4,4'-(9-fluorenylidene)-dianiline, 3,3'-dichloro-4,4'-diaminodiphenylmethane, 2,2'-dichloro-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, and 4,4'-diaminodiphenylthioether.

[0053] The above polyimide resin preferably has a weight-average molecular weight (Mw) of 20,000 to 180,000 of polyethylene oxide standards when developed using a dimethylformamide solution (prepared by adding 10 mM lithium bromide and 10 mM phosphoric acid to make up 1 L of dimethylformamide solution) as the developing solvent, and a preferred imidation rate of 95% or more. The above imidation rate can be determined from the integrated intensity ratio of the proton peak derived from polyamic acid, a precursor of polyimide, and the proton peak derived from polyimide.

[0054] For example, the negative C plate may be composed of a polyarylate resin. A polyarylate resin having a predetermined substituent exhibits high birefringence, and a coating obtained by applying a resin solution of this polymer onto a substrate can be used as a negative C plate. Details of the polyarylate resin having a predetermined substituent are described, for example, in Japanese Patent Application Publication No. 2009-80440, and the descriptions in these publications are incorporated herein by reference.

[0055] Examples of display devices to which the optical component arrangement structure according to embodiments of the present invention can be suitably used include near-eye displays such as VR goggles.

[0056] Figure 2 is a schematic diagram showing the general configuration of an example of a display system included in VR goggles. Figure 2 schematically illustrates the arrangement and shape of each component of the display system. The display system 2 comprises a display element 12, a reflective polarizing member 14, a first lens section 16, a half mirror 18, a first phase difference member 20, and a second phase difference member 22. The reflective polarizing member 14 is positioned in front of the display surface 12a of the display element 12 (right side in Figure 2) and can reflect light emitted from the display element 12. The first lens section 16 is positioned in the optical path between the display element 12 and the reflective polarizing member 14, and the half mirror 18 is positioned between the display element 12 and the first lens section 16. The first phase difference member 20 is positioned in the optical path between the display element 12 and the half mirror 18, and the second phase difference member 22 is positioned in the optical path between the half mirror 18 and the reflective polarizing member 14. A second lens section may also be provided, although it is not shown. The second lens portion may be provided, for example, in front of the reflective polarizing member 14.

[0057] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. Light emitted from the display surface 12a passes through, for example, a polarizing member 12b included in the display element 12 and is emitted as first linearly polarized light.

[0058] The first phase difference member 20 can convert a first linearly polarized light incident on the first phase difference member 20 into a first circularly polarized light. The first phase difference member 20 may be provided integrally with the display element 12.

[0059] The half mirror 18 transmits light emitted from the display element 12 and reflects the light reflected by the reflective polarizing member 14 back towards the reflective polarizing member 14. The half mirror 18 may be integrally provided with the first lens portion 16.

[0060] The second phase difference member 22 can transmit light reflected by the reflective polarizing member 14 and the half mirror 18 through the reflective polarizing member 14. The second phase difference member 22 may be integrally provided with the first lens portion 16, or it may be integrally provided with the second lens portion. In the latter case, the second phase difference member 22 may be integrally provided with the second lens portion together with the reflective polarizing member 14, for example.

[0061] The first circularly polarized light emitted from the first phase difference member 20 passes through the half mirror 18 and the first lens portion 16 and is converted into a second linearly polarized light by the second phase difference member 22. The second linearly polarized light emitted from the second phase difference member 22 is reflected towards the half mirror 18 without passing through the reflective polarizing member 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member 14 is in the same direction as the reflection axis of the reflective polarizing member 14. Therefore, the second linearly polarized light incident on the reflective polarizing member 14 is reflected by the reflective polarizing member 14.

[0062] The second linearly polarized light reflected by the reflective polarizing member 14 is converted into a second circularly polarized light by the second phase difference member 22, and the second circularly polarized light emitted from the second phase difference member 22 passes through the first lens portion 16 and is reflected by the half mirror 18. The circularly polarized light reflected by the half mirror 18 passes through the first lens portion 16 and is converted into a third linearly polarized light by the second phase difference member 22. The third linearly polarized light is transmitted through the reflective polarizing member 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member 14 is in the same direction as the transmission axis of the reflective polarizing member 14. Therefore, the third linearly polarized light incident on the reflective polarizing member 14 is transmitted through the reflective polarizing member 14. The light transmitted through the reflective polarizing member 14 is incident on the user's eye 3.

[0063] For example, the absorption axis of the polarizing member 12b included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be arranged substantially parallel to each other, or substantially orthogonal to each other.

[0064] As shown in Figure 2, in the display system 2, an absorptive polarizing member 28 may be provided in front of the reflective polarizing member 14. The reflection axis of the reflective polarizing member 14 and the absorption axis of the absorptive polarizing member 28 may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member 14 and the transmission axis of the absorptive polarizing member 28 may be arranged substantially parallel to each other. The absorptive polarizing member 28 may be provided integrally with the reflective polarizing member 14.

[0065] Figure 3 is a schematic diagram showing the general configuration of a display system included in a display body according to another embodiment of the present invention. In the display system 2 shown in Figure 2, the optical member arrangement structure 1 can be provided, for example, behind the first phase difference member 20 (on the left side of Figure 2). In the display system 200 shown in Figure 3, the polarizing member 12b included in the display element 12 is the first polarizing member 31 of the optical member arrangement structure 1, and the adjustment member 30 and the second polarizing member 32 are provided between the display element 12 and the first phase difference member 20. The adjustment member 30 and the second polarizing member 32 may be provided integrally with the display element 12.

[0066] Figure 4 is a schematic diagram showing the general configuration of a display system included in a display body according to yet another embodiment of the present invention. In the display system 2 shown in Figure 2, the optical member arrangement structure 1 can be provided, for example, in front of the reflective polarizing member 14. In the display system 201 shown in Figure 4, the absorptive polarizing member 28 is the first polarizing member 31 of the optical member arrangement structure 1, and the adjustment member 30 and the second polarizing member 32 are provided in front of the absorptive polarizing member 28. Note that, unlike the example shown in Figure 4, the absorptive polarizing member 28 may be omitted, and the reflective polarizing member 14 may be the first polarizing member 31 of the optical member arrangement structure 1. The adjustment member 30 and the second polarizing member 32 may be provided integrally with the absorptive polarizing member 28 and / or the reflective polarizing member 14.

[0067] By forming the above-mentioned arrangement structure of optical elements in a display system included in a near-eye display, it is possible to cut off light emitted at an oblique angle from the display surface of the display element and suppress the generation of stray light caused by light reflection at the edges of the lens or the inner wall of the housing. This reduces the so-called ghosting phenomenon, in which images appear to overlap. In one embodiment, from the viewpoint of more effectively suppressing the generation of stray light, it is preferable to form the arrangement structure 1 of the optical elements as close as possible to the display element 12 (for example, behind the half mirror 18).

[0068] The reflective polarizing member 14 transmits light with polarization parallel to its transmission axis (typically linear polarization) while maintaining its polarization state, and reflects light with other polarization states (typically light with polarization perpendicular to its transmission axis). The reflective polarizing member is typically composed of a multilayer film (sometimes referred to as a reflective polarizing film). In this case, the thickness of the reflective polarizing member is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

[0069] Figure 5 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 14a alternates between layers A, which have birefringence, and layers B, which have substantially no birefringence. The total number of layers constituting the multilayer structure may be 50 to 1000. For example, the refractive index nx in the x-axis direction of layer A is greater than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction and the refractive index ny in the y-axis direction of layer B are substantially the same, so the refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction can be the reflection axis and the y-axis direction can be the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3.

[0070] The above-mentioned layer A is typically composed of a material that exhibits birefringence upon stretching. Examples of such materials include naphthalenedicarboxylic acid polyester (e.g., polyethylene naphthalate), polycarbonate, and acrylic resins (e.g., polymethyl methacrylate). The above-mentioned layer B is typically composed of a material that does not substantially exhibit birefringence upon stretching. Examples of such materials include a copolyester of naphthalenedicarboxylic acid and terephthalic acid. The above multilayer structure can be formed by a combination of co-extrusion and stretching. For example, the materials constituting layer A and layer B are extruded and then multilayered (e.g., using a multiplier). The resulting multilayer laminate is then stretched. The x-axis direction in the illustrated example may correspond to the stretching direction.

[0071] Examples of commercially available reflective polarizing films include the product names "DBEF" and "APF" from 3M, and "APCF" from Nitto Denko.

[0072] The orthogonal transmittance (Tc) of the reflective polarizing member (reflective polarizing film) may be, for example, 0.001% to 3%. The single-element transmittance (Ts) of the reflective polarizing member (reflective polarizing film) may be, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing member (reflective polarizing film) may be, for example, 92% to 99.99%.

[0073] Each of the first retardation member 20 and the second retardation member 22 (hereinafter, may be simply referred to as a retardation member) can typically be a retardation member capable of converting linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light. The retardation member may be composed of a single layer or may have a laminated structure.

[0074] When the retardation member is composed of a single layer, typically, the retardation member can be a λ / 4 member. The in-plane retardation Re(550) of the λ / 4 member is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm.

[0075] The λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the λ / 4 member is, for example, less than 1, may be 0.95 or less, may further be less than 0.90, or may further be 0.85 or less. Re(450) / Re(550) of the λ / 4 member is, for example, 0.75 or more.

[0076] In one embodiment, the λ / 4 member satisfies all of Re(400) / Re(SS0) < 0.85, Re(650) / Re(550) > 1.03, and Re(TS0) / Re(550) > 1.05. The λ / 4 member preferably satisfies at least one selected from 0.65 < Re(400) / Re(550) < 0.80 (preferably, 0.7 < Re(400) / Re(550) < 0.75), 1.0 < Re(650) / Re(550) < 1.25 (preferably, 1.05 < Re(650) / Re(550) < 1.20), and 1.05 < Re(750) / Re(550) < 1.40 (preferably, 1.08 < Re(750) / Re(550) < 1.36), more preferably satisfies at least two, and still more preferably satisfies all.

[0077] The λ / 4 member may, for example, exhibit a refractive index characteristic showing the relationship nx > ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, ny < nz may occur. The Nz coefficient of the λ / 4 member is preferably from 0.9 to 3, more preferably from 0.9 to 2.5, still more preferably from 0.9 to 1.5, and particularly preferably from 0.9 to 1.3.

[0078] The λ / 4 member that can satisfy the above characteristics may be, for example, a stretched film of a resin film or an alignment and solidification layer of a liquid crystal compound.

[0079] Examples of the resin contained in the resin film include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, acrylic resins, etc. These resins may be used alone or in combination (for example, blended or copolymerized). When the λ / 4 member exhibits an inverse dispersion wavelength characteristic, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) may be preferably used.

[0080] As the polycarbonate resin described above, any suitable polycarbonate resin can be used as long as the effects of the present invention are obtained. For example, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanol, di, tri, or polyethylene glycol, and alkylene glycol or spiroglycol. Preferably, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic dimethanol, and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may optionally include structural units derived from other dihydroxy compounds. Further details regarding polycarbonate resins suitably used for λ / 4 members and methods for forming λ / 4 members are described, for example, in Japanese Patent Publication Nos. 2014-10291, 2014-26266, 2015-212816, 2015-212817, and 2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0081] The orientation-solidified layer of the above-mentioned liquid crystal compound is a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer, and this orientation state is fixed. Note that the term "orientation-solidified layer" is a concept that includes the orientation-cured layer obtained by curing liquid crystal monomers, as described later. In the λ / 4 member, typically, rod-shaped liquid crystal compounds are oriented in a state where they are aligned along the slow axis direction of the λ / 4 member (homogenous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. Preferably, the liquid crystal compound is polymerizable. If the liquid crystal compound is polymerizable, the orientation state of the liquid crystal compound can be fixed by polymerizing it after orientation.

[0082] The above-mentioned oriented solidified layer of liquid crystal compound (liquid crystal oriented solidified layer) can be formed by applying an orientation treatment to the surface of a predetermined substrate, coating the surface with a coating liquid containing the liquid crystal compound to orient the liquid crystal compound in the direction corresponding to the orientation treatment, and fixing the orientation state. Any appropriate orientation treatment can be used as the orientation treatment. Specifically, these include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatment include magnetic field orientation treatment and electric field orientation treatment. Specific examples of chemical orientation treatment include oblique deposition and photo-orientation treatment. Any appropriate conditions can be adopted for each orientation treatment depending on the purpose.

[0083] The orientation of liquid crystal compounds is achieved by treating them at a temperature that exhibits the liquid crystal phase, depending on the type of liquid crystal compound. This temperature treatment causes the liquid crystal compound to enter a liquid crystal state, and it then orients according to the orientation treatment direction on the substrate surface.

[0084] In one embodiment, the orientation state is fixed by cooling the liquid crystal compound oriented as described above. If the liquid crystal compound is polymerizable or crosslinkable, the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment.

[0085] As the above-mentioned liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer may be used individually or in combination. Specific examples of liquid crystal compounds and methods for producing liquid crystal alignment solidified layers are described, for example, in Japanese Patent Publication No. 2006-163343, Japanese Patent Publication No. 2006-178389, and International Publication No. 2018 / 123551. The descriptions in these publications are incorporated herein by reference.

[0086] The thickness of the λ / 4 member, which is composed of a stretched resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 60 μm, and even more preferably 20 μm to 50 μm. The thickness of the λ / 4 member, which is composed of a liquid crystal alignment solidification layer, is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

[0087] The angle between the absorption axis of the polarizing member 12b and the slow axis of the first phase difference member 20, which is a λ / 4 member, is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The angle between the absorption axis of the polarizing member 12b and the slow axis of the second phase difference member 22, which is a λ / 4 member, is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°.

[0088] When the phase difference member has a laminated structure, typically the phase difference member has a laminated structure including a λ / 2 layer and a λ / 4 layer.

[0089] The in-plane phase difference Re(550) of the λ / 2 layer is, for example, 200 nm to 330 nm, but may also be 230 nm to 330 nm, 230 nm to 290 nm, or 250 nm to 280 nm.

[0090] The in-plane phase difference Re(550) of the λ / 4 layer is, for example, 100 nm to 200 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm.

[0091] Each of the λ / 2 layer and the λ / 4 layer (hereinafter, may be simply referred to as the layer included in the laminated structure) preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the layer included in the laminated structure is, for example, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

[0092] The layer included in the laminated structure may exhibit a flat wavelength dispersion characteristic in which the retardation value hardly changes depending on the wavelength of the measurement light. In this case, Re(450) / Re(550) of the layer included in the laminated structure may be, for example, 0.99 to 1.03, and Re(650) / Re(550) may be, for example, 0.98 to 1.02.

[0093] The layer included in the laminated structure may, for example, exhibit a refractive index characteristic showing a relationship of nx > ny ≧ nz. Here, “ny = nz” includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, ny < nz may occur. The Nz coefficient of the layer included in the laminated structure is preferably 0.9 to 3, more preferably 0.9 to 2.5, still more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0094] The layer included in the laminated structure is formed of any suitable material that can satisfy the above characteristics. The layer included in the laminated structure may be, for example, a stretched film of a resin film or an alignment cured layer of a liquid crystal compound. Details of the stretched film of the resin film and the alignment cured layer of the liquid crystal compound are as described above. When the layer included in the laminated structure has a flat wavelength dispersion characteristic, preferred examples of the forming material include cycloolefin resins, particularly norbornene resins.

[0095] Norbornene-based resins are resins polymerized using norbornene-based monomers as polymerization units. Examples of norbornene-based monomers include norbornene and its alkyl and / or alkylidene-substituted derivatives, such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, and their halogen- and other polar group-substituted derivatives; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc. Dimetanooctahydronaphthalene, its alkyl and / or alkylidene substituted derivatives, and polar group substituted derivatives such as halogens, e.g., 6-methyl-1,4:5,8-dimetano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4:5,8-dimetano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4:5,8-dimetano-1,4,4a,5,6 7,8,8a-Octahydronaphthalene, 6-Chloro-1,4:5,8-Dimetano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Cyano-1,4:5,8-Dimetano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Pyridyl-1,4:5,8-Dimetano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Methoxycarbonyl-1,4:5,8-Dimetano Examples include tano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, and tripers or tetramers of cyclopentadiene, such as 4,9:5,8-dimethano-3a,4,4a,5,8,8a,9,9a-octahydro-1H-benzoindene and 4,11:5,10:6,9-trimethano-3a,4,4a,5,5a,6,9,9a,10,10a,11,11a-dodecahydro-1H-cyclopentaanthracene. The norbornene-based resin may also be a copolymer of a norbornene-based monomer and another monomer.

[0096] The above description of the λ / 4 member can be applied to the thickness of the λ / 4 layer. The thickness of the λ / 2 layer, which is composed of a stretched resin film, is, for example, 20 μm to 200 μm, preferably 20 μm to 140 μm, more preferably 20 μm to 120 μm, and even more preferably 40 μm to 100 μm. The thickness of the λ / 2 layer, which is composed of a liquid crystal alignment solidification layer, is, for example, 2 μm to 20 μm, preferably 2 μm to 16 μm, more preferably 2 μm to 12 μm, and even more preferably 2 μm to 8 μm. The same description as above for the λ / 2 layer can be applied to the details of the forming material and thickness of the λ / 2 member, which exhibits the above refractive index characteristic of nx > ny ≥ nz.

[0097] In the phase difference member, the angle between the slow axis of the λ / 2 layer and the slow axis of the λ / 4 layer is preferably 50° to 70°, more preferably 55° to 65°, even more preferably 57° to 63°, and particularly preferably about 60°. In one embodiment, the angle between the absorption axis of the polarizing member 12b and the slow axis of the λ / 2 layer is preferably 5° to 35°, more preferably 10° to 20°, even more preferably 12° to 18°, and particularly preferably about 15°. The angle between the absorption axis of the polarizing member 12b and the slow axis of the λ / 4 layer is preferably 55° to 85°, more preferably 70° to 80°, even more preferably 72° to 78°, and particularly preferably about 75°. In another embodiment, the angle between the absorption axis of the polarizing member 12b and the slow axis of the λ / 4 layer is preferably 5° to 35°, more preferably 10° to 20°, even more preferably 12° to 18°, and particularly preferably about 15°. The angle between the absorption axis of the polarizing member 12b and the slow axis of the λ / 2 layer is preferably 55° to 85°, more preferably 70° to 80°, even more preferably 72° to 78°, and particularly preferably about 75°.

[0098] The first phase difference member 20 and the second phase difference member 22 may be members with the same configuration (forming material, thickness, optical properties, etc.), or they may be members with different configurations. For example, from the viewpoint of manufacturing efficiency, the first phase difference member 20 and the second phase difference member 22 may have the same configuration.

[0099] In the above display system, for example, from the viewpoint of improving visibility, a high degree of adjustment may be required between the phase difference value of the first phase difference member 20 and the phase difference value of the second phase difference member 22. For example, the absolute value of the difference between the in-plane phase difference (a) of the first phase difference member 20 and the in-plane phase difference (b) of the second phase difference member 22 is, for example, 3.5 nm or less, preferably 3.0 nm or less, more preferably 2.5 nm or less, even more preferably 2.0 nm or less, particularly preferably 1.5 nm or less, and most preferably 1.0 nm or less. (a) and (b) are, for example, values ​​of Re(590).

[0100] Furthermore, for example, it is preferable that the in-plane phase difference (a) of the first phase difference member 20 and the in-plane phase difference (b) of the second phase difference member 22 satisfy the following formula (I). ((a)-(b)) / ((a)+(b) / 2)≦0.02···(I) More preferably ((a)-(b)) / ((a)+(b) / 2)≦0.015, and even more preferably ((a)-(b)) / ((a)+(b) / 2)≦0.01.

[0101] In one embodiment, a set of optical components may be provided, having optical components that can be provided in the display system described above. The integration of multiple optical components can typically be achieved by laminating each optical component via an arbitrary suitable adhesive layer. [Examples]

[0102] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The test and evaluation methods in the examples are as follows.

[0103] (1) Thickness Thicknesses of 10 μm or less were measured using a scanning electron microscope (JEOL Ltd., product name "JSM-7100F"). Thicknesses exceeding 10 μm were measured using a digital micrometer (Anritsu Corporation, product name "KC-351C"). (2) Phase difference value Phase difference / elliptic polarization measurement devices (manufactured by Oji Instruments Co., Ltd., product names "KOBRA-HBR" and "KOBRA-HBPR") were used to measure the phase difference value at a predetermined wavelength at 23°C. (3) Transmittance and degree of polarization of polarizing film The single-unit transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of the polarizing film were measured using a spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200"). These Ts, Tp, and Tc values ​​are Y values ​​obtained by measuring under a 2-degree field of view (C light source) according to JIS Z 8701 and correcting for luminous sensitivity. From the obtained Tp and Tc values, the polarization degree of the polarizing film was determined using the following formula. Degree of polarization (%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0104] [Manufacturing Example 1: Fabrication of λ / 2 component 1] A long norbornene-based resin film with refractive index characteristics nx>ny>nz (manufactured by Zeon Corporation, product name "ZB12-063225", thickness: 60 μm, Re(550): 63 nm, Rth(550): 256.5 nm, Nz coefficient: 4.07) was prepared. This film had a Re(450) / Re(550) ratio of 1.004, exhibiting substantially flat dispersion wavelength characteristics.

[0105] Four films cut from the prepared film were stacked together with an adhesive to obtain a laminate (λ / 2 member 1). The resulting laminate had a Re(550) of 252 nm, a Rth(550) of 1026 nm, and an Nz coefficient of 4.07.

[0106] [Manufacturing Example 2: Fabrication of λ / 2 component 2] A long norbornene-based resin film (manufactured by Zeon Corporation, product name "Zeonor", thickness: 50 μm) was prepared. The stretching ratio and stretching temperature were adjusted so that Re(550) was 275 nm, and the film was stretched in the longitudinal direction at the free end to obtain a stretched film (λ / 2 member 2) with a thickness of 33 μm. The obtained stretched film had a refractive index characteristic of nx>ny=nz, and Re(450) / Re(550) was 1.004, exhibiting substantially flat dispersion wavelength characteristics.

[0107] [Manufacturing Example 3: Fabrication of λ / 2 component 3] A long norbornene-based resin film with refractive index characteristics nx>ny>nz (manufactured by Zeon Corporation, product name "e-ZB12-052125", thickness: 52 μm, Re(550): 52 nm, Rth(550): 151 nm, Nz coefficient: 2.90) was prepared. This film had a Re(450) / Re(550) ratio of 1.004, exhibiting substantially flat dispersion wavelength characteristics. A stretched film was obtained by stretching the prepared elongated film 1.1 times in the width direction (a direction perpendicular to the length direction). This stretched film had a refractive index of nx>ny>nz, a thickness of 50 μm, a Re(550) of 63 nm, a Rth(550) of 126 nm, an Nz coefficient of 2.0, and a Re(450) / Re(550) of 1.004, exhibiting substantially flat dispersion wavelength characteristics.

[0108] Four films cut from the stretched film were stacked together with an adhesive to obtain a laminate (λ / 2 member 3). The resulting laminate had a Re(550) of 252 nm, a Rth(550) of 504 nm, and an Nz coefficient of 2.0.

[0109] [Manufacturing Example 4: Fabrication of Member 1 with a Phase Difference in the Thickness Direction] A liquid crystal coating solution was prepared by dissolving 20 parts by weight of a side-chain liquid crystal polymer represented by the following chemical formula (1) (the numbers 65 and 35 in the formula indicate the mole percent of monomer units and are conveniently represented as a block polymer: weight-average molecular weight 5000), 80 parts by weight of a polymerizable liquid crystal exhibiting a nematic liquid crystal phase (BASF: trade name Paliocolor LC242), and 5 parts by weight of a photopolymerization initiator (Ciba Specialty Chemicals: trade name Irgacure 907) in 200 parts by weight of cyclopentanone. [ka]

[0110] A prepared coating solution was applied to a substrate film (norbornene-based resin film, manufactured by Zeon Corporation, trade name "Zeonex") using a bar coater, and then the liquid crystal was oriented by heating and drying at 80°C for 4 minutes. By irradiating this liquid crystal layer with ultraviolet light and curing it, a positive C plate with a thickness of 5 μm, a refractive index of nz>nx=ny, and an Rth(590) of -130 nm was formed on the substrate film. The obtained positive C plate had an Rth(450) / Rth(550) of 1.072, exhibiting positive dispersion wavelength characteristics.

[0111] Five of the above positive C plates were stacked together with an adhesive to obtain a laminate (member 1 that gives a phase difference in the thickness direction). The obtained laminate had an Rth(550) of -650 nm.

[0112] [Manufacturing Example 5: Fabrication of Member 2 with a Phase Difference in the Thickness Direction] A solution (concentration: 10 wt%) of polyimide synthesized from 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropanoic acid dianhydride and 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl dissolved in methyl isobutyl ketone (MIBK) was applied to a substrate (triacetylcellulose film with a thickness of 80 μm) to obtain a coating film with a thickness of 27 μm. Subsequently, the coating film was subjected to a drying treatment at 120°C for 10 minutes to form a negative C plate on the substrate with a thickness of approximately 2.7 μm, a refractive index of nx=ny>nz, and an Rth(590) of 162.5 nm.

[0113] Four of the above negative C plates were stacked together with an adhesive to obtain a laminate (member 2 that provides a phase difference in the thickness direction). The obtained laminate had an Rth(550) of 650 nm.

[0114] [Manufacturing Example 6: Production of Polarizing Film] As a thermoplastic resin substrate, an amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 μm) in a long length with a Tg of approximately 75°C was used, and one side of the resin substrate was subjected to corona treatment. A PVA aqueous solution (coating solution) was prepared by dissolving 100 parts by weight of a PVA-based resin, which was prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "Gosenex Z410") in a 9:1 ratio, with 13 parts by weight of potassium iodide. A PVA aqueous solution was applied to the corona-treated surface of a resin substrate and dried at 60°C to form a 13 μm thick PVA-based resin layer, thereby creating a laminate. The resulting laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130°C (air-assisted stretching). Next, the laminate was immersed for 30 seconds in an insolubilization bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) (insolubilization treatment). Next, the laminate was immersed for 60 seconds in a staining bath at a liquid temperature of 30°C (an iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) while adjusting the concentration so that the transmittance (Ts) of the final absorption polarizing film would be the desired value (staining treatment). Next, the laminate was immersed for 30 seconds in a crosslinking bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) (crosslinking treatment). Subsequently, the laminate was immersed in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70°C, and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to achieve a total stretch ratio of 5.5 times (underwater stretching treatment). Subsequently, the laminate was immersed in a washing bath at a liquid temperature of 20°C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) (washing treatment). Subsequently, the laminate was dried in an oven maintained at approximately 90°C while being brought into contact with a SUS (stainless steel) heated roll whose surface temperature was maintained at approximately 75°C (drying shrinkage treatment). The shrinkage rate in the width direction of the laminate due to the drying shrinkage treatment was 5.2%. In this way, an absorption-type polarizing film with a thickness of approximately 5 μm was formed on a resin substrate. A cycloolefin resin film (thickness: 25 μm) was bonded to the surface of the obtained absorption polarizing film (the side opposite to the resin substrate) via an ultraviolet-curing adhesive. Specifically, the curing adhesive was applied to a total thickness of approximately 1 μm and bonded using a roll press. Then, UV light was irradiated from the cycloolefin resin film side to cure the adhesive. Next, the resin substrate was peeled off. This resulted in a polarizing film having a cycloolefin resin film / absorption polarizing film structure. The transmittance (Ts) of the polarizing film was 43.4%, and the degree of polarization was 99.993%.

[0115] [Manufacturing Example 7: Fabrication of Optical Component A] Optical member A was obtained by bonding the polarizing film to the λ / 2 member 1 via an adhesive layer with a thickness of 5 μm. At this time, the polarizing film was bonded so that the absorption axis of the polarizing film and the slow axis of the λ / 2 member 1 formed a 45° angle. In addition, the polarizing film was bonded so that the absorbing polarizing film was located on the side of the λ / 2 member 1.

[0116] [Manufacturing Example 8: Fabrication of Optical Component B] A member 1 that provides a phase difference in the thickness direction was bonded to one side of the λ / 2 member 2 via an adhesive layer with a thickness of 5 μm. The polarizing film was bonded to the other side of the λ / 2 member 2 via an adhesive layer with a thickness of 5 μm to obtain optical member B. At this time, the polarizing film was bonded so that the absorption axis of the polarizing film and the slow axis of the λ / 2 member 2 formed a 45° angle. In addition, the polarizing film was bonded so that the absorbing polarizing film was located on the side of the λ / 2 member 2.

[0117] [Manufacturing Example 9: Fabrication of Optical Component C] An optical component C was obtained by bonding the polarizing film to a glass plate via an adhesive layer with a thickness of 5 μm. The polarizing film was bonded so that the absorbing polarizing layer was located on the glass plate side.

[0118] [Manufacturing Example 10: Fabrication of Optical Component D] An optical component D was obtained by overlapping two of the above-mentioned polarizing films onto a glass plate with a 5 μm thick adhesive layer in between. The polarizing films were bonded so that the absorbing polarizing film of each film was positioned on the glass plate side. At this time, the two polarizing films were overlapped so that their absorption axes were parallel to each other. Furthermore, the polarizing films were overlapped so that the absorbing polarizing film of each film was positioned on the glass plate side.

[0119] [Manufacturing Example 11: Fabrication of Optical Component E] The polarizing film was bonded to the λ / 2 member 3 via an adhesive layer with a thickness of 5 μm to obtain the optical member E. At this time, the polarizing film was bonded so that the absorption axis of the polarizing film and the slow axis of the λ / 2 member 3 formed a 45° angle. In addition, the polarizing film was bonded so that the absorbing polarizing film was located on the λ / 2 member 3 side.

[0120] [Manufacturing Example 12: Fabrication of Optical Component F] A member 2 that provides a phase difference in the thickness direction was bonded to one side of the λ / 2 member 2 via an adhesive layer with a thickness of 5 μm. The polarizing film was bonded to the other side of the λ / 2 member 2 via an adhesive layer with a thickness of 5 μm to obtain an optical member F. At this time, the polarizing film was bonded so that the absorption axis of the polarizing film and the slow axis of the λ / 2 member 2 formed a 45° angle. In addition, the polarizing film was bonded so that the absorbing polarizing film was located on the side of the λ / 2 member 2.

[0121] <Examples and Comparative Examples> As shown in Table 1, in Examples 1 to 4, the optical components from the above manufacturing example were arranged vertically to form an optical laminate. When the absorption axis of the polarizing film of the optical component placed on the upper side is taken as the reference (0°), the optical component placed on the lower side was positioned so that the absorption axis of the polarizing film was at an angle of 90°. As shown in Table 2, in Comparative Example 1, only optical component C was used, and in Comparative Example 2, only optical component D was used. Since both absorbing and reflective polarizing members can transmit linearly polarized light but not linearly polarized light perpendicular to it, only absorbing polarizing members are used in the evaluation for convenience.

[0122] [Table 1]

[0123] [Table 2]

[0124] <Rating> The transmittance in the front direction and the transmittance in the oblique direction of the optical laminate of the example and the optical component of the comparative example (hereinafter referred to as the measurement sample) were measured using a Müller matrix polarimeter (Axometrics, product name "AxoScan"). Specifically, at 23°C, the transmittance was measured by irradiating the upper main surface of the measurement sample with light of wavelength 550 nm from directions with azimuth angles of 0°, 45°, 90°, and 135° at polar angles of 0° and 45°. The measurement results are shown in Table 3. Note that in Table 3, the transmittance in the oblique direction (45°) is the average value of four values ​​with different azimuth angles. Furthermore, the results of transmittance measurements performed by changing the polar angle at each azimuth angle (0°, 45°, 90°, 135°) are shown in Figures 6 to 9.

[0125] [Table 3]

[0126] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the configurations shown in the embodiments above can be replaced with configurations that are substantially the same, configurations that produce the same effects, or configurations that can achieve the same purpose. [Industrial applicability]

[0127] The arrangement structure of optical elements according to the embodiment of the present invention can be used, for example, in a display device such as VR goggles. [Explanation of Symbols]

[0128] 1. Arrangement structure of optical components, 2. Display system, 3. User's eye, 12. Display element, 12a. Display surface, 12b. Polarizing member, 14. Reflective polarizing member, 16. First lens section, 18. Half mirror, 20. First phase difference member, 22. Second phase difference member, 28. Absorbing polarizing member, 30. Adjustment member, 31. First polarizing member, 32. Second polarizing member, 100. Display body, 200. Display system, 201. Display system.

Claims

1. An arrangement structure of optical elements provided on a display device that displays images to a user, It comprises a first polarizing member, an adjusting member, and a second polarizing member. The first polarizing member, the adjusting member, and the second polarizing member are arranged in this order facing the user. The adjusting member includes a λ / 2 member, When the second polarizing member is viewed from the user's side, the transmission axis of the second polarizing member and the transmission axis of the first polarizing member are approximately perpendicular, and the transmission axis of the second polarizing member and the lagging axis of the λ / 2 member form an angle of 40° to 50°. Arrangement structure of optical components.

2. The optical member arrangement structure according to claim 1, wherein the ratio of the transmittance in the oblique direction of the optical laminate to the transmittance in the front direction of the optical laminate, in which the first polarizing member, the adjusting member, and the second polarizing member are stacked in this order, is 0.85 or less.

3. The optical member arrangement structure according to claim 1, wherein the transmittance in the oblique direction of the optical laminate, in which the first polarizing member, the adjusting member, and the second polarizing member are stacked in this order, is 30% or less.

4. The optical member arrangement structure according to claim 1, wherein the absolute value of the phase difference Rth(550) in the thickness direction of the adjusting member is 500 nm or more.

5. The optical member arrangement structure according to claim 4, wherein the Nz coefficient of the λ / 2 member is 2.0 or greater.

6. The arrangement structure for an optical member according to claim 4, wherein the adjusting member further includes a member that provides a phase difference in the thickness direction, and the absolute value of the phase difference Rth(550) in the thickness direction of the member that provides a phase difference in the thickness direction is 300 nm or more and 1000 nm or less.

7. A display body having the arrangement structure of optical members according to any one of claims 1 to 6, wherein the display body comprises a liquid crystal display or an organic EL display.

8. A display body having the arrangement structure of optical members according to any one of claims 1 to 6, wherein the display body is a near-eye display.

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