Lens unit, display body and display method

Abstract

To provide a lens part capable of achieving weight-saving and improved visibility of a VR goggle.SOLUTION: A lens part is to be used in a display system configured to display an image to a user. The lens part includes: a reflection type polarization member configured to reflect light emitted forward from a display face of a display element showing the image and transmitted through a polarization member and a first λ / 4 member; a first lens part arranged on an optical path between the display element and the reflection type polarization member; a half mirror arranged between the display element and the first lens part and configured to transmit the emitted light from the display element and reflect the light reflected at the reflection type polarization member toward the reflection type polarization member; a second lens part arranged in front of the reflection type polarization member; and a second λ / 4 member arranged on an optical path between the half mirror and the reflection type polarization member. With regard to an aggregate composed by aligning three first laminate parts each including the second λ / 4 member and at least one layer of adhesive layer, an ISC value is 100 or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lens unit, a display, and a display method. [Background technology]

[0002] Image display devices, such as liquid crystal display devices and electroluminescence (EL) display devices (e.g., organic EL display devices), are rapidly becoming popular. In image display devices, optical components such as polarizing components and phase difference components are generally used to realize image display and improve the performance of the image display (see, for example, Patent Document 1).

[0003] In recent years, new applications for image display devices have been developed. For example, goggles with displays (VR goggles) for realizing virtual reality (VR) have begun to be commercialized. As VR goggles are being considered for use in a variety of situations, there is a demand for them to be lightweight and have improved visibility. Weight reduction can be achieved, for example, by thinning the lenses used in VR goggles. Meanwhile, there is also a demand for the development of optical components suitable for display systems using thin lenses. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-103286 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, a main object of the present invention is to provide a lens portion that can reduce the weight of VR goggles and improve visibility. [Means for solving the problem]

[0006] 1. A lens unit according to an embodiment of the present invention is a lens unit used in a display system that displays images to a user, and comprises: a reflective polarizing element that reflects light that is emitted forward from a display surface of a display element that displays an image and that has passed through a polarizing element and a first λ / 4 element; a first lens unit that is arranged on the optical path between the display element and the reflective polarizing element; a half mirror that is arranged between the display element and the first lens unit and that transmits light that is emitted from the display element and reflects light reflected by the reflective polarizing element toward the reflective polarizing element; a second lens unit that is arranged in front of the reflective polarizing element; and a second λ / 4 element that is arranged on the optical path between the half mirror and the reflective polarizing element, and the ISC value of an assembly formed by arranging three first laminated elements, each including the second λ / 4 element and at least one adhesive layer, is 100 or less. 2. The lens portion described in 1 above may have a second laminated portion including the reflective polarizing member. 3. In the lens portion described in 2 above, the first laminated portion and the second laminated portion may be disposed apart from each other. 4. In the lens section according to 2 or 3 above, the second stacked section may include an absorptive polarizing member disposed between the reflective polarizing member and the second lens section. 5. In the lens section described in any one of 2 to 4 above, the second stacked section may include a third λ / 4 member disposed between the reflective polarizing member and the second lens section. 6. In the lens unit described in any one of 1 to 5 above, the first laminated portion may include a first protective member disposed in front of the second λ / 4 member. 7. In the lens portion according to any one of the above items 1 to 6, the first laminated portion may include three or fewer pressure-sensitive adhesive layers. 8. In the lens portion according to any one of the above 1 to 7, the thickness of each of the pressure-sensitive adhesive layers included in the first laminate portion may be 20 μm or less. 9. In the lens portion according to any one of 1 to 8 above, the surface roughness Ra of each of the pressure-sensitive adhesive layers included in the first laminate portion may be 20 nm or less. 10. In the lens portion according to any one of the above items 1 to 9, each of the pressure-sensitive adhesive layers included in the first laminate portion may be a single layer. 11. In the lens section described in any one of 1 to 10 above, the first lens section and the half mirror may be integral with each other. 12. A display according to an embodiment of the present invention has a lens portion as described in any one of 1 to 11 above.

[0007] 13. A display method according to an embodiment of the present invention includes the steps of: passing light representing an image emitted through a polarizing element and a first λ / 4 element through a half mirror and a first lens unit; passing the light that has passed through the half mirror and the first lens unit through a second λ / 4 element; reflecting the light that has passed through the second λ / 4 element toward the half mirror with a reflective polarizing element; making the light reflected by the reflective polarizing element and the half mirror transmittant through the reflective polarizing element with the second λ / 4 element; and passing the light that has transmitted through the reflective polarizing element through a second lens unit, wherein the ISC value of an assembly formed by arranging three first laminate units each including the second λ / 4 element and at least one adhesive layer is 100 or less. [Effects of the Invention]

[0008] The lens portion according to the embodiment of the present invention can reduce the weight of the VR goggles and improve visibility. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a schematic diagram showing a general configuration of a display system according to an embodiment of the present invention. [Figure 2] 2 is a schematic cross-sectional view showing an example of the details of a lens unit of the display system shown in FIG. 1. FIG. [Figure 3] FIG. 1 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. [Figure 4] FIG. 1 is a diagram for explaining a method for measuring an ISC value. DETAILED DESCRIPTION OF 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. In addition, in order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than in the embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0011] (Definition of terms and symbols) The definitions of terms and symbols used in this specification are as follows. (1) Refractive index (nx, ny, nz) "nx" is the refractive index in the direction in which the in-plane refractive index is greatest (i.e., the slow axis direction), "ny" is the refractive index in the direction perpendicular 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 retardation measured with light of wavelength λ nm at 23°C. For example, "Re(550)" is the in-plane retardation measured with light of wavelength 550 nm at 23°C. Re(λ) is calculated by the formula: Re(λ)=(nx-ny)×d, where d (nm) is the thickness of the layer (film). (3) Retardation in the thickness direction (Rth) "Rth(λ)" is the retardation in the thickness direction measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the retardation in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) is calculated by the formula: Rth(λ) = (nx - nz) × d, where d (nm) is the thickness of the layer (film). (4) Nz coefficient The Nz coefficient is calculated by Nz=Rth / Re. (5)Angle When angles are referred to herein, the angles include both clockwise and counterclockwise angles relative to a reference direction, so for example, "45°" means ±45°.

[0012] FIG. 1 is a schematic diagram showing the overall configuration of a display system according to one embodiment of the present invention. FIG. 1 schematically illustrates the arrangement and shape of each component of a display system 2. The display system 2 includes a display element 12, a reflective polarizing element 14, a first lens unit 16, a half mirror 18, a first phase difference element 20, a second phase difference element 22, and a second lens unit 24. The reflective polarizing element 14 is disposed in front of the display surface 12a of the display element 12 and can reflect light emitted from the display element 12. The first lens unit 16 is disposed on the optical path between the display element 12 and the reflective polarizing element 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first phase difference element 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second phase difference element 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing element 14.

[0013] The components arranged in front of the half mirror (in the illustrated example, the half mirror 18, the first lens section 16, the second phase difference member 22, the reflective polarizing member 14, and the second lens section 24) may be collectively referred to as the lens section (lens section 4).

[0014] 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 polarizing member (typically, a polarizing film) that may be included in the display element 12, and is converted into first linearly polarized light.

[0015] The first phase difference member 20 includes a first λ / 4 member that can convert first linearly polarized light incident on the first phase difference member 20 into first circularly polarized light. When the first phase difference member does not include any member other than the first λ / 4 member, the first phase difference member may correspond to the first λ / 4 member. The first phase difference member 20 may be provided integrally with the display element 12.

[0016] The half mirror 18 transmits the light emitted from the display element 12 and reflects the light reflected by the reflective polarizing member 14 back toward the reflective polarizing member 14. The half mirror 18 is provided integrally with the first lens portion 16.

[0017] The second phase difference member 22 includes a second λ / 4 member that can transmit light reflected by the reflective polarizing member 14 and the half mirror 18 through the reflective polarizing member 14. When the second phase difference member does not include any member other than the second λ / 4 member, the second phase difference member may correspond to the second λ / 4 member. The second phase difference member 22 may be provided integrally with the first lens unit 16.

[0018] The first circularly polarized light emitted from the first λ / 4 element included in the first phase difference element 20 passes through the half mirror 18 and the first lens unit 16, and is converted into the second linearly polarized light by the second λ / 4 element included in the second phase difference element 22. The second linearly polarized light emitted from the second λ / 4 element is reflected toward the half mirror 18 without passing through the reflective polarizing element 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing element 14 is the same as the reflection axis of the reflective polarizing element 14. Therefore, the second linearly polarized light incident on the reflective polarizing element 14 is reflected by the reflective polarizing element 14.

[0019] The second linearly polarized light reflected by the reflective polarizing element 14 is converted into second circularly polarized light by the second λ / 4 element included in the second phase difference element 22, and the second circularly polarized light output from the second λ / 4 element passes through the first lens unit 16 and is reflected by the half mirror 18. The second circularly polarized light reflected by the half mirror 18 passes through the first lens unit 16 and is converted into third linearly polarized light by the second λ / 4 element included in the second phase difference element 22. The third linearly polarized light is transmitted through the reflective polarizing element 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing element 14 is the same as the transmission axis of the reflective polarizing element 14. Therefore, the third linearly polarized light incident on the reflective polarizing element 14 is transmitted through the reflective polarizing element 14.

[0020] The light transmitted through the reflective polarizing member 14 passes through the second lens portion 24 and enters the eye 26 of the user.

[0021] For example, the absorption axis of the polarizing member included in the display element 12 and the reflection axis of the reflective polarizing member 14 may be disposed approximately parallel to each other or approximately perpendicular to each other. The angle formed between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the first λ / 4 member included in the first retardation member 20 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°. The angle formed between the absorption axis of the polarizing member included in the display element 12 and the slow axis of the second λ / 4 member included in the second retardation member 22 is, for example, 40° to 50°, or may be 42° to 48°, or may be approximately 45°.

[0022] The in-plane retardation Re(550) of the first λ / 4 component is, for example, 100 nm to 190 nm, or alternatively, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ / 4 component preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the first λ / 4 component may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0023] The in-plane retardation Re(550) of the second λ / 4 component is, for example, 100 nm to 190 nm, or alternatively, 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The second λ / 4 component preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the second λ / 4 component may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less.

[0024] In the lens unit 4, a space may be formed between the first lens unit 16 and the second lens unit 24. In this case, the member disposed between the first lens unit 16 and the second lens unit 24 is preferably provided integrally with either the first lens unit 16 or the second lens unit 24. For example, the member disposed between the first lens unit 16 and the second lens unit 24 is preferably integrated with either the first lens unit 16 or the second lens unit 24 via an adhesive layer. This configuration can improve the ease of handling of each member, for example. The adhesive layer may be formed of an adhesive or a pressure-sensitive adhesive. Specifically, the adhesive layer may be an adhesive layer or a pressure-sensitive adhesive layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

[0025] FIG. 2 is a schematic cross-sectional view showing an example of the details of the lens unit of the display system shown in FIG. 1. Specifically, FIG. 2 shows a first lens unit, a second lens unit, and members disposed therebetween. The lens unit 4 includes a first lens unit 16, a first stack unit 100 disposed adjacent to the first lens unit 16, a second lens unit 24, and a second stack unit 200 disposed adjacent to the second lens unit 24. In the example shown in FIG. 2, the first stack unit 100 and the second stack unit 200 are disposed apart from each other. Although not shown, a half mirror may be provided integrally with the first lens unit 16.

[0026] The first laminated unit 100 includes a second retardation member 22 and an adhesive layer 41 disposed between the first lens unit 16 and the second retardation member 22, and is integrally formed with the first lens unit 16 by the adhesive layer 41. The first laminated unit 100 further includes a first protective member 31 disposed in front of the second retardation member 22. The first protective member 31 is laminated on the second retardation member 22 via the adhesive layer 42. The first protective member 31 can be located on the outermost surface of the first laminated unit 100.

[0027] In the example shown in FIG. 2, the second retardation member 22 includes, in addition to the second λ / 4 member 22a, a member (so-called positive C plate) 22b having a refractive index characteristic showing a relationship of nz > nx = ny. The second retardation member 22 has a laminated structure of the second λ / 4 member 22a and the positive C plate 22b. As shown in FIG. 2, in the second retardation member 22, it is preferable that the second λ / 4 member 22a is positioned forward of the positive C plate 22b. The second λ / 4 member 22a and the positive C plate 22b are laminated via, for example, an adhesive layer not shown in the figure.

[0028] The above second λ / 4 member preferably shows 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 not impairing the effects of the present invention, ny < nz may occur. The Nz coefficient of the second λ / 4 member 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.

[0029] The second λ / 4 member is formed of any suitable material that can satisfy the above characteristics. The second λ / 4 member can be, for example, a stretched film of a resin film or an alignment cured layer of a liquid crystal compound.

[0030] 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. Examples of the combination method include blending and copolymerization. When the second λ / 4 member shows inverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) can be preferably used.

[0031] Any suitable polycarbonate-based resin can be used as the polycarbonate-based resin. For example, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanols, di-, tri-, or polyethylene glycols, and alkylene glycols or spiroglycols. Preferably, the polycarbonate-based resin contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, structural units derived from an alicyclic dimethanol, and / or structural units derived from di-, tri-, or polyethylene glycol; more preferably, it contains structural units derived from a fluorene-based dihydroxy compound, structural units derived from an isosorbide-based dihydroxy compound, and structural units derived from di-, tri-, or polyethylene glycol. The polycarbonate-based resin may contain structural units derived from other dihydroxy compounds as needed. Details of polycarbonate resins suitable for use in the second λ / 4 member and methods for forming the second λ / 4 member are described, for example, in JP 2014-10291 A, JP 2014-26266 A, JP 2015-212816 A, JP 2015-212817 A, and JP 2015-212818 A, and the descriptions in these publications are incorporated herein by reference.

[0032] The thickness of the second λ / 4 member made of a stretched resin film is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.

[0033] The above-mentioned liquid crystal compound alignment solidified layer is a layer in which the liquid crystal compound is aligned in a predetermined direction within the layer and the alignment state is fixed. The term "alignment solidified layer" encompasses a concept including an alignment solidified layer obtained by solidifying a liquid crystal monomer, as described below. In the second λ / 4 member, typically, rod-shaped liquid crystal compounds are aligned in the slow axis direction of the second λ / 4 member (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably polymerizable. If the liquid crystal compound is polymerizable, the alignment state of the liquid crystal compound can be fixed by aligning the liquid crystal compound and then polymerizing it.

[0034] The alignment and solidification layer of the liquid crystal compound (liquid crystal alignment and solidification layer) can be formed by performing an alignment treatment on the surface of a predetermined substrate, applying a coating liquid containing a liquid crystal compound to the surface to align the liquid crystal compound in a direction corresponding to the alignment treatment, and fixing the alignment state. Any appropriate alignment treatment can be used as the alignment treatment. Specific examples include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include rubbing treatment and stretching treatment. Specific examples of physical alignment treatment include magnetic field alignment treatment and electric field alignment treatment. Specific examples of chemical alignment treatment include oblique vapor deposition and photoalignment treatment. Any appropriate treatment conditions can be used for the various alignment treatments depending on the purpose.

[0035] The alignment of liquid crystal compounds is achieved by treating them at a temperature at which they exhibit a liquid crystal phase depending on the type of liquid crystal compound. By performing such temperature treatment, the liquid crystal compounds assume a liquid crystal state and are aligned in accordance with the alignment treatment direction on the substrate surface.

[0036] In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. When the liquid crystal compound is polymerizable or crosslinkable, the alignment state is fixed by subjecting the liquid crystal compound aligned as described above to a polymerization treatment or crosslinking treatment.

[0037] Any suitable liquid crystal polymer and / or liquid crystal monomer can be used as the liquid crystal compound. The liquid crystal polymer and the liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for producing a liquid crystal alignment solidified layer are described in, for example, JP 2006-163343 A, JP 2006-178389 A, and WO 2018 / 123551 A. The descriptions in these publications are incorporated herein by reference.

[0038] The thickness of the second λ / 4 member formed of the liquid crystal alignment solidified 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.

[0039] The thickness direction retardation Rth(550) of the positive C plate is preferably -50 nm to -300 nm, more preferably -70 nm to -250 nm, even more preferably -90 nm to -200 nm, and particularly preferably -100 nm to -180 nm. Here, "nx = ny" includes not only the case where nx and ny are strictly equal, but also the case where nx and ny are substantially equal. The in-plane retardation Re(550) of the positive C plate is, for example, less than 10 nm.

[0040] The positive C plate can be formed from any suitable material, but is preferably composed of a film containing a liquid crystal material fixed in homeotropic alignment. The liquid crystal material (liquid crystal compound) that can be homeotropically aligned may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of such liquid crystal compounds and methods for forming a positive C plate include the liquid crystal compounds and methods for forming the retardation layer described in

[0020] to

[0028] of JP 2002-333642 A. In this case, the thickness of the positive C plate is preferably 0.5 μm to 5 μm.

[0041] The first protective member typically includes a substrate. The thickness of the substrate is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm. The substrate may be made of any appropriate film. Examples of materials that form the main component of the film constituting the substrate include cellulose-based resins such as triacetyl cellulose (TAC), polyester-based, polyvinyl alcohol-based, polycarbonate-based, polyamide-based, polyimide-based, polyethersulfone-based, polysulfone-based, polystyrene-based, cycloolefin-based resins such as polynorbornene, polyolefin-based, (meth)acrylic, and acetate-based resins. Here, (meth)acrylic refers to acrylic and / or methacrylic. In one embodiment, the substrate is preferably made of a (meth)acrylic resin. By using a (meth)acrylic resin, a substrate with excellent smoothness can be formed by extrusion molding. As a result, a protective member with excellent smoothness can be obtained.

[0042] The first protective member preferably has a substrate and a surface treatment layer formed on the substrate. The first protective member having the surface treatment layer can be disposed so that the surface treatment layer is located on the front side. Specifically, the surface treatment layer can be located on the outermost surface of the first laminated portion. The surface treatment layer can have any appropriate function. For example, from the viewpoint of improving visibility, the surface treatment layer preferably has an anti-reflection function. The thickness of the surface treatment layer is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

[0043] The second laminated member 200 includes a reflective polarizing member 14 and an adhesive layer disposed between the reflective polarizing member 14 and the second lens unit 24. For example, from the viewpoint of improving visibility, the second laminated member 200 further includes an absorptive polarizing member 28 disposed between the reflective polarizing member 14 and the second lens unit 24. The absorptive polarizing member 28 is laminated in front of the reflective polarizing member 14 via an adhesive layer 44. The reflection axis of the reflective polarizing member 14 and the absorption axis of the absorptive polarizing member 28 may be disposed 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 disposed substantially parallel to each other. By laminating the reflective polarizing member 14 and the absorptive polarizing member 28 via the adhesive layer, the reflective polarizing member 14 and the absorptive polarizing member 28 are fixed, preventing misalignment of the reflection axis and the absorption axis (transmission axis and transmission axis). Furthermore, adverse effects of an air gap that may form between the reflective polarizing member 14 and the absorptive polarizing member 28 can be suppressed.

[0044] The second laminate 200 further includes a second protective member 32 disposed behind the reflective polarizing member 14. The second protective member 32 is laminated to the reflective polarizing member 14 via an adhesive layer 43. The second protective member 32 may be located on the outermost surface of the second laminate 200. Like the first protective member, the second protective member may include a substrate. The second protective member preferably includes a substrate and a surface treatment layer formed on the substrate. In this case, the surface treatment layer may be located on the outermost surface of the second laminate. The same explanation as for the first protective member applies to the details of the substrate and the surface treatment layer.

[0045] As shown in FIG. 2, the second laminated unit 200 may further include a third phase difference member 30 disposed between the absorptive polarizing member 28 and the second lens unit 24. The third phase difference member 30 is laminated to the absorptive polarizing member 28 via an adhesive layer 45. The third phase difference member 30 is laminated to the second lens unit 24 via an adhesive layer 46, and the second laminated unit 200 is provided integrally with the second lens unit 24. The third phase difference member 30 includes, for example, a third λ / 4 member. The angle between the absorption axis of the absorptive polarizing member 28 and the slow axis of the third λ / 4 member included in the third phase difference member 30 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°. By providing such a member, for example, it is possible to prevent reflection of external light from the second lens unit 16 side. When the third phase difference member does not include any member other than the third λ / 4 member, the third phase difference member may correspond to the third λ / 4 member.

[0046] The reflective polarizing element transmits polarized light parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarization state, and can reflect light in other polarization states. The reflective polarizing element is typically made of a film (sometimes referred to as a reflective polarizing film) having a multilayer structure. In this case, the thickness of the reflective polarizing element is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

[0047] FIG. 3 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 14a has alternating birefringent layers A and layers B that are substantially not birefringent. 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 larger 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, and 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.

[0048] The A layer is typically made of a material that exhibits birefringence upon stretching. Examples of such materials include naphthalenedicarboxylic acid polyesters (e.g., polyethylene naphthalate), polycarbonates, and acrylic resins (e.g., polymethyl methacrylate). The B layer is typically made of a material that does not substantially exhibit birefringence upon stretching. Examples of such materials include copolyesters of naphthalenedicarboxylic acid and terephthalic acid. The multilayer structure can be formed by a combination of coextrusion and stretching. For example, the materials constituting the A layer and the B layer 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 corresponds to the stretching direction.

[0049] Commercially available reflective polarizing films include, for example, "DBEF" and "APF" manufactured by 3M, and "APCF" manufactured by Nitto Denko Corporation.

[0050] The crossed transmittance (Tc) of the reflective polarizing member (reflective polarizing film) can be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing member (reflective polarizing film) can be, for example, 43% to 49%, preferably 45% to 47%. The polarization degree (P) of the reflective polarizing member (reflective polarizing film) can be, for example, 92% to 99.99%.

[0051] The crossed transmittance, single transmittance, and degree of polarization can be measured, for example, using an ultraviolet-visible spectrophotometer. The degree of polarization P can be calculated from the obtained Tp and Tc by measuring the single transmittance Ts, parallel transmittance Tp, and crossed transmittance Tc using an ultraviolet-visible spectrophotometer, using the following formula. Note that Ts, Tp, and Tc are Y values ​​measured using a 2-degree visual field (C light source) according to JIS Z 8701 and corrected for luminosity. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0052] The absorptive polarizing member may typically include a resin film (sometimes referred to as an absorptive polarizing film) containing a dichroic material. The thickness of the absorptive polarizing film is, for example, 1 μm or more and 20 μm or less, or may 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.

[0053] The absorptive polarizing film may be made from a single layer of resin film or may be made from a laminate of two or more layers.

[0054] When fabricating from a single-layer resin film, an absorptive polarizing film can be obtained by dyeing 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 with iodine or a dichroic substance such as a dichroic dye, stretching, etc. Among these, an absorptive polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0055] The dyeing with iodine is carried out, for example, by immersing the PVA film in an aqueous iodine solution. The stretching ratio of the uniaxial stretching is preferably 3 to 7 times. The stretching may be carried out after the dyeing treatment or while dyeing. Alternatively, the stretching may be followed by dyeing. If necessary, the PVA film may be subjected to a swelling treatment, a crosslinking treatment, a washing treatment, a drying treatment, etc.

[0056] Examples of laminates produced using the two or more layer laminate 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 formed by coating on the resin substrate. An absorptive polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer formed by coating on the resin substrate can be produced, for example, by applying a PVA-based resin solution to the resin substrate and drying the resin substrate to form a PVA-based resin layer on the resin substrate, thereby obtaining a laminate of the resin substrate and the PVA-based resin layer; and then stretching and dyeing the laminate to convert the PVA-based resin layer into an absorptive polarizing film. In this embodiment, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is preferably formed on one side of the resin substrate. The stretching typically involves immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, the stretching may further include, if necessary, in-air stretching of the laminate at an elevated temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. Additionally, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment by heating while being transported in the longitudinal direction, thereby shrinking the laminate by 2% or more in the width direction. Typically, the manufacturing method of this embodiment includes subjecting the laminate to an in-air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment, 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, thereby achieving high optical properties. Furthermore, by simultaneously increasing the orientation of PVA in advance, problems such as a decrease in orientation or dissolution of PVA when immersed in water in the subsequent dyeing and stretching steps can be prevented, thereby achieving high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disordering 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 a halide. This can improve the optical properties of an absorptive polarizing film obtained through treatment steps, such as dyeing and underwater stretching, in which the laminate is immersed in a liquid. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through drying shrinkage treatment.The obtained resin substrate / absorptive polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorptive polarizing film), or any suitable protective layer may be laminated depending on the purpose on the surface obtained by peeling the resin substrate from the resin substrate / absorptive polarizing film laminate, or on the surface opposite to the peeled surface. Details of such methods for producing absorptive polarizing films are described in, for example, JP 2012-73580 A and Japanese Patent No. 6470455 A. The entire disclosures of these publications are incorporated herein by reference.

[0057] The crossed transmittance (Tc) of the absorptive polarizing element (absorptive polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single transmittance (Ts) of the absorptive polarizing element (absorptive polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The polarization degree (P) of the absorptive polarizing element (absorptive polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0058] The in-plane retardation Re(550) of the third λ / 4 member is, for example, 100 nm to 190 nm, or may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The third λ / 4 member preferably exhibits inverse dispersion wavelength characteristics in which the retardation value increases according to the wavelength of the measurement light. The Re(450) / Re(550) of the third λ / 4 member may be, for example, 0.75 or more and less than 1, or 0.8 or more and 0.95 or less. The refractive index characteristics of the third λ / 4 member preferably exhibit the relationship nx>ny≧nz. The Nz coefficient of the third λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3.

[0059] The third λ / 4 member is formed of any appropriate material that can satisfy the above characteristics. The third λ / 4 member can be, for example, a stretched resin film or an oriented and solidified layer of a liquid crystal compound. The same explanation as for the second λ / 4 member can be applied to a third λ / 4 member formed of a stretched resin film or an oriented and solidified layer of a liquid crystal compound. The second λ / 4 member and the third λ / 4 member may be members having the same configuration (e.g., forming material, thickness, optical properties, etc.) or may be members having different configurations.

[0060] In the lens unit 4, the ISC value of an assembly formed by arranging three first laminate units from a member located in front of the first lens unit 16 to a member located behind the reflective polarizing member 14 is 100 or less, preferably 90 or less, more preferably 80 or less, and even more preferably 70 or less. By satisfying such an ISC value, a display system with extremely excellent visibility can be realized. Specifically, by satisfying such an ISC value, the generation of diffused light in the lens unit can be suppressed, thereby preventing the image from becoming unclear. The ISC value can be an index of smoothness or unevenness. Furthermore, the ISC value of an assembly formed by arranging three first laminate units can be an index of the visibility of the entire display system. Since light can pass through the first laminate unit three times in the display system, the first laminate unit can significantly affect the visibility of the display system. In the example shown in FIG. 2, for example, from the perspective of convenience of evaluation, the first laminate unit 100 includes a member located behind the space formed between the first lens unit 16 and the reflective polarizing member 14. Specifically, the first laminated section 100 includes an adhesive layer 41, a second retardation member 22 including a second λ / 4 member 22a, an adhesive layer 42, and a first protective member 31. In practice, the lower limit of the ISC value of an assembly formed by arranging three first laminated sections is about 5.

[0061] In the example shown in FIG. 2, six pressure-sensitive adhesive layers 41 to 46 are used to integrally form each component disposed between the first lens unit 16 and the second lens unit 24 with the first lens unit 16 or the second lens unit 24. In the example shown in FIG. 2, the first laminate unit 100 includes two pressure-sensitive adhesive layers. For example, the number of pressure-sensitive adhesive layers included in the first laminate unit 100 varies depending on the number of components disposed between the first lens unit 16 and the reflective polarizing member 14. The first laminate unit includes preferably three or fewer pressure-sensitive adhesive layers, and more preferably two or fewer pressure-sensitive adhesive layers. According to this embodiment, the first laminate unit can satisfactorily achieve the above ISC value.

[0062] The thickness of the pressure-sensitive adhesive layer used to laminate the above-mentioned members can be set to any appropriate thickness. The thickness of each pressure-sensitive adhesive layer used to laminate the above-mentioned members is preferably 20 μm or less, and may be 15 μm or less, 10 μm or less, or 7 μm or less. With such a thickness, the degree of unevenness on the pressure-sensitive adhesive layer surface can be suppressed, and the above-mentioned ISC value can be satisfactorily achieved in the first laminated portion. Meanwhile, the thickness of the pressure-sensitive adhesive layer is, for example, 3 μm or more.

[0063] The surface roughness Ra of each of the pressure-sensitive adhesive layers used to laminate the above members is preferably 20 nm or less, more preferably 15 nm or less. With such a thickness, the above ISC value can be satisfactorily achieved in the first laminated portion.

[0064] The pressure-sensitive adhesive layer can be composed of any appropriate pressure-sensitive adhesive. Specific examples include acrylic pressure-sensitive adhesives, rubber pressure-sensitive adhesives, silicone pressure-sensitive adhesives, polyester pressure-sensitive adhesives, urethane pressure-sensitive adhesives, epoxy pressure-sensitive adhesives, and polyether pressure-sensitive adhesives. By adjusting the type, number, combination, and compounding ratio of monomers forming the base resin of the pressure-sensitive adhesive, as well as the compounding amount of cross-linking agent, reaction temperature, reaction time, etc., a pressure-sensitive adhesive having desired properties according to the purpose can be prepared. The base resin of the pressure-sensitive adhesive may be used alone or in combination of two or more types. An acrylic resin is preferably used as the base resin. Specifically, the pressure-sensitive adhesive layer is preferably composed of an acrylic pressure-sensitive adhesive.

[0065] For example, the pressure-sensitive adhesive layer can be formed by applying a pressure-sensitive adhesive composition containing a base resin, additives such as a crosslinking agent, and a solvent, followed by drying. The pressure-sensitive adhesive composition may be applied directly to the adherend, or may be applied to a separately prepared substrate such as a base film. Drying is typically performed by heating.

[0066] For example, the surface roughness Ra can be satisfied by adjusting the film thickness of the coating film of the pressure-sensitive adhesive composition. If the film thickness is too thick, heating may cause liquid flow in the coating film due to temperature differences, and a pressure-sensitive adhesive layer with a large degree of surface irregularity may be formed.

[0067] Furthermore, for example, the surface roughness Ra can be satisfied by controlling the drying conditions for the coating film of the pressure-sensitive adhesive composition. Specifically, the surface roughness Ra can be satisfied by adjusting the volume and speed of the air blown onto the coating film during drying. If the volume and speed of the air blown onto the coating film are too high, waves may form in the coating film, resulting in a pressure-sensitive adhesive layer with a large degree of surface irregularity. In one embodiment, the coating film is preferably dried in a temperature environment of 65°C to 110°C at an air speed adjusted to a range of 2 m / min to 15 m / min, more preferably 2 m / min to 8 m / min. For example, after coating, the temperature and air speed are preferably adjusted to these values ​​near the entrance of the oven used for drying. Specifically, the temperature and air speed can be adjusted to these values ​​from the entrance of the oven to the center of the oven.

[0068] The pressure-sensitive adhesive layers used to laminate the above-mentioned members are preferably each composed of a single layer. For example, it is preferable that each pressure-sensitive adhesive layer does not have a multilayer structure formed by applying the pressure-sensitive adhesive composition two or more times. When the pressure-sensitive adhesive layer is composed of a single layer, for example, the above-mentioned surface roughness Ra can be satisfied. [Example]

[0069] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The thickness, surface roughness Ra, and retardation value are values ​​measured by the following measurement methods. <Thickness> Thicknesses of 10 μm or less were measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"), and thicknesses of more than 10 μm were measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C"). <Surface roughness Ra> The arithmetic mean surface roughness Ra (μm) was measured according to JIS B 0601 (1994 edition). The measurement sample was prepared by bonding the adhesive layer to a glass plate (MATSUNAMI Micro Slide Glass, part number S, 1.3 mm thick, 45 mm x 50 mm). The adhesive layer was bonded by transferring the adhesive layer formed on the substrate film from the substrate film to the glass plate. The resulting measurement sample was measured using a scanning white light interferometer (Zygo, product name "Newview7300"). Specifically, the measurement sample was placed on a vibration-isolated measurement table, and interference fringes were generated using a single white LED light. An interference objective lens (2.5x magnification) with a reference plane was scanned in the Z direction (thickness direction) to selectively obtain the smoothness (surface smoothness) of the outermost surface of the adhesive layer within a 2 mm square field of view. Based on this measurement, the arithmetic mean surface roughness (Ra) was calculated. <Phase difference value> The phase difference value at each wavelength at 23°C was measured using a Mueller matrix polarimeter (manufactured by Axometrics, product name "Axoscan").

[0070] [Example 1] (Formation of adhesive layer) A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with a monomer mixture containing 92 parts by weight of butyl acrylate, 2.9 parts by weight of acrylic acid, 0.1 parts by weight of 2-hydroxyethyl acrylate, and 5 parts by weight of N-acryloylmorpholine. Furthermore, 0.1 parts by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator and 200 parts by weight of ethyl acetate were charged to 100 parts by weight of this monomer mixture. Nitrogen gas was introduced into the flask with gentle stirring to replace the atmosphere with nitrogen, and the polymerization reaction was carried out for 8 hours while maintaining the liquid temperature in the flask at around 55°C, producing an acrylic polymer solution with a weight-average molecular weight (Mw) of 1.78 million. The acrylic polymer solution was applied to the substrate film, and the resulting coating on the substrate film was dried in an oven to form a pressure-sensitive adhesive layer with a thickness of 5 μm and a surface roughness Ra of 12 nm. The drying was performed by adjusting the air speed in the oven from the oven entrance to the center to a range of 15 m / min or less. The air speed was measured using an anemometer installed in the oven.

[0071] (Fabrication of λ / 4 components) Polymerization was carried out using a batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled at 100° C. The polymerization mixture contained 29.60 parts by mass (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by mass (0.200 mol) of isosorbide (ISB), 42.28 parts by mass (0.139 mol) of spiroglycol (SPG), 63.77 parts by mass (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10 calcium acetate monohydrate as a catalyst. -2 Part of mass (6.78×10 -5 (mol) was charged. After purging the reactor with nitrogen under reduced pressure, heating was performed using a heat transfer medium. Stirring was initiated when the internal temperature reached 100°C. Forty minutes after the start of the temperature increase, the internal temperature reached 220°C. This temperature was maintained while simultaneously reducing the pressure. 90 minutes after reaching 220°C, the pressure was reduced to 13.3 kPa. Phenol vapor by-produced during the polymerization reaction was introduced into a reflux condenser at 100°C, and the small amount of monomer components contained in the phenol vapor was returned to the reactor. Uncondensed phenol vapor was collected by introducing nitrogen into the first reactor and temporarily restoring the pressure to atmospheric pressure. The oligomerized reaction liquid in the first reactor was then transferred to the second reactor. Next, heating and depressurization of the second reactor were initiated, and the internal temperature reached 240°C and the pressure reached 0.2 kPa in 50 minutes. The polymerization was then allowed to proceed until the specified stirring power was reached. When the predetermined power was reached, nitrogen was introduced into the reactor to restore pressure, and the polyester carbonate resin produced was extruded into water, and the strands were cut to obtain pellets.

[0072] The resulting polyester carbonate resin pellets were vacuum-dried at 80°C for 5 hours and then used in a film-making machine equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder temperature setting: 250°C), a T-die (width: 200 mm, temperature setting: 250°C), a chill roll (temperature setting: 120-130°C), and a winder to produce a 135 μm thick long resin film. The resulting long resin film was stretched in the width direction at a stretching temperature of 143°C and a stretch ratio of 2.8 to obtain a 47 μm thick stretched film. The resulting stretched film had an Re(550) of 143 nm, an Re(450) / Re(550) of 0.86, and an Nz coefficient of 1.2.

[0073] (Positive C-plate formation) 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 represent the mole percent of the monomer unit, and are conveniently expressed 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. The coating solution was then applied to a PET substrate that had been subjected to vertical alignment treatment using a bar coater, and the liquid crystal was aligned by heating and drying at 80°C for 4 minutes. The liquid crystal layer was irradiated with ultraviolet light to harden it, forming a positive C-plate with a thickness of 4 μm and an Rth(550) of -100 nm on the substrate. [ka]

[0074] (Production of protective material) The hard coat layer-forming material described below was applied to an acrylic film (thickness: 40 μm) having a lactone ring structure and heated at 90°C for 1 minute. After heating, the applied layer was irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating layer was cured by irradiation with ultraviolet light of 1000 kJ / cm, thereby producing an acrylic film (thickness: 44 μm) on which a hard coat layer having a thickness of 4 μm was formed. Next, the following coating solution A for forming an antireflection layer was applied onto the hard coat layer using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp at an integrated light intensity of 300 mJ / cm. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm 2 , thereby forming an antireflection layer A having a thickness of 140 nm. Next, the following coating solution B for forming an antireflection layer was applied onto the antireflection layer A using a wire bar, and the applied coating solution was heated at 80°C for 1 minute and dried to form a coating film. The dried coating film was irradiated with an integrated light dose of 300 mJ / cm using a high-pressure mercury lamp. 2 The coating was cured by irradiating it with ultraviolet light of 1000 kJ / cm 2 , thereby forming an antireflection layer B having a thickness of 105 nm. In this way, a protective member (thickness: 44 μm) was obtained.

[0075] (Hard Coat Layer Forming Material) A hard coat layer-forming material was prepared by mixing 50 parts of a urethane acrylic oligomer (manufactured by Shin-Nakamura Chemical Co., Ltd., "NK Oligo UA-53H"), 30 parts of a multifunctional acrylate whose main component is pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Ltd., trade name "Viscoat #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Ltd.), 1 part of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts of a photopolymerization initiator (manufactured by Ciba Japan, "Irgacure 907") and diluting with methyl isobutyl ketone to a solids concentration of 50%.

[0076] (Anti-reflection layer forming coating solution A) 100 parts by weight of a multifunctional acrylate (manufactured by Arakawa Chemical Industries, Ltd., trade name "Opstar KZ6728", solid content 20% by weight), 3 parts by weight of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight) were mixed. The mixture was diluted with butyl acetate as a dilution solvent to a solid content of 12% by weight, and the mixture was stirred to prepare Coating Solution A for forming an antireflection layer.

[0077] (Anti-reflection layer forming coating solution B) 100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as the main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300", solid content 100 wt%), 150 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Industries, Ltd., trade name "Sururia 5320", solid content 20 wt%, weight average particle diameter 75 nm), 50 parts by weight of solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., trade name "MEK-2140Z-AC", solid content 30 wt%, weight average particle diameter 10 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KY-1203", solid content 20 wt%), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100 wt%) were mixed. To this mixture, a mixed solvent of TBA (tertiary butyl alcohol), MIBK (methyl isobutyl ketone), and PMA (propylene glycol monomethyl ether acetate) in a weight ratio of 60:25:15 was added as a dilution solvent to make the total solid content 4% by weight, and the mixture was stirred to prepare coating solution B for forming an anti-reflection layer.

[0078] (First stacked part) The positive C plate described below was attached to the λ / 4 member (stretched film) via an ultraviolet-curable adhesive (thickness after curing: 1 μm) to obtain a retardation member. The obtained retardation member was attached to a glass plate (MICRO SLIDE GLASS, product number S, thickness 1.3 mm, 180 mm × 250 mm, manufactured by MATSUNAMI Co., Ltd.) via the above-mentioned 5 μm-thick adhesive layer, with the positive C plate of the retardation member facing the glass plate. Next, the protective member was attached to the retardation member via the 5 μm-thick adhesive layer to obtain a first laminated portion on the glass plate, with the acrylic film of the protective member facing the retardation member.

[0079] (Fabrication of an absorption polarizing film) The thermoplastic resin substrate was a long, amorphous isophthalic copolymerized polyethylene terephthalate film (thickness: 100 μm) with a water absorption rate of 0.75% and a Tg of approximately 75° C. One side of the resin substrate was subjected to a corona treatment. A PVA aqueous solution (coating liquid) was prepared by dissolving 100 parts by weight of a PVA-based resin made by mixing polyvinyl alcohol (polymerization degree 4200, saponification degree 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "Gohsenex Z410") in a 9:1 ratio, to which 13 parts by weight of potassium iodide was added, in water. The above PVA aqueous solution was applied to the corona treated surface of the resin substrate and dried at 60° C. to form a PVA resin layer with a thickness of 13 μm, thereby producing a laminate. The resulting laminate was uniaxially stretched at its free end to 2.4 times its original size in the machine direction (longitudinal direction) between rolls with different peripheral speeds in an oven at 130°C (auxiliary in-air stretching treatment). Next, the laminate was immersed in an insolubilizing bath (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insolubilizing treatment). Next, the film was immersed in a dye bath (an aqueous iodine solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds while adjusting the concentration so that the single transmittance (Ts) of the final polarizing film would be 42.0% or higher (dyeing treatment). Next, the sample was immersed in a crosslinking bath (a boric acid aqueous solution obtained by blending 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (crosslinking treatment). The laminate was then immersed in a boric acid aqueous solution (boric acid concentration 4 wt %, potassium iodide concentration 5 wt %) at a liquid temperature of 70°C and uniaxially stretched in the longitudinal direction (longitudinal direction) between rolls with different peripheral speeds to a total stretch ratio of 5.5 times (underwater stretching treatment). Thereafter, the laminate was immersed in a cleaning bath (aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 20° C. (cleaning treatment). Thereafter, while drying in an oven maintained at 90°C, the laminate was brought into contact with a SUS heated roll whose surface temperature was maintained at 75°C for approximately 2 seconds (drying shrinkage treatment). The shrinkage rate in the width direction of the laminate due to the drying shrinkage treatment was 5.2%. In this manner, a polarizing film (absorptive polarizing film) having a thickness of 5 μm was formed on the resin substrate.

[0080] (Second laminated part) The absorptive polarizing film was attached to a glass plate (MICRO SLIDE GLASS, product number S, thickness 1.3 mm, 180 mm×250 mm, manufactured by MATSUNAMI Co., Ltd.) via the 5 μm-thick adhesive layer. Next, a reflective polarizing film ("APCF" manufactured by Nitto Denko Corporation) was attached to the absorptive polarizing film via the above-mentioned 5 μm-thick adhesive layer so that the reflection axis of the reflective polarizing film and the absorption axis of the absorptive polarizing film were arranged parallel to each other. Next, the protective member was attached to the reflective polarizing film to obtain a second laminate on the glass plate, with the acrylic film of the protective member facing the reflective polarizing film.

[0081] [Example 2] A first laminate part and a second laminate part were obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive layer shown below was used. (Formation of adhesive layer) A four-neck flask equipped with a stirring blade, thermometer, nitrogen gas inlet tube, and condenser was charged with a monomer mixture containing 94.9 parts by weight of butyl acrylate, 5 parts by weight of acrylic acid, and 0.1 parts by weight of 2-hydroxyethyl acrylate. Furthermore, 0.3 parts by weight of dibenzoyl peroxide as a polymerization initiator was charged along with ethyl acetate for 100 parts by weight of this monomer mixture. Nitrogen gas was introduced into the flask with gentle stirring to replace the atmosphere with nitrogen. The temperature in the flask was maintained at 60°C, and the polymerization reaction was carried out for 7 hours. Ethyl acetate was then added to the resulting reaction solution to adjust the solids concentration to 30% by weight, producing an acrylic polymer solution with a weight-average molecular weight (Mw) of 2.2 million. An acrylic adhesive was prepared by blending 0.6 parts by weight of a trimethylolpropane / tolylene diisocyanate adduct (trade name: Coronate L, manufactured by Tosoh Corporation) and 0.075 parts by weight of a silane coupling agent (trade name: KBM403, manufactured by Shin-Etsu Chemical Co., Ltd.) with 100 parts by weight of the solid content of the obtained acrylic polymer solution. The resulting acrylic adhesive was coated onto a substrate film, and the resulting coating on the substrate film was dried in an oven to form an adhesive layer with a thickness of 15 μm and a surface roughness Ra of 16 nm. The drying was performed by adjusting the air speed in the oven from the oven entrance to the center to a range of 15 m / min or less.

[0082] [Comparative Example 1] The first laminated part and the second laminated part were obtained in the same manner as in Example 2, except that in forming the adhesive layer, the air speed in the oven was adjusted to within a range of 15 m / min or less, and an adhesive layer with a thickness of 15 μm and a surface roughness Ra of 22 nm was formed.

[0083] Comparative Example 2 The first laminated part and the second laminated part were obtained in the same manner as in Example 2, except that in forming the adhesive layer, the coating thickness of the acrylic adhesive was changed and the air speed in the oven was adjusted to within a range of 15 m / min or less to form an adhesive layer with a thickness of 23 μm and a surface roughness Ra of 29 nm.

[0084] The ISC values ​​of the first laminated parts of the examples and comparative examples were measured using EyeScale-4W manufactured by i-System Co., Ltd. Specifically, based on the specifications of the measuring device, the in-plane unevenness of the first laminated part and the second laminated part was calculated as the ISC value in the ISC measurement mode of the 3CCD image sensor. 4 is a diagram for explaining a method for measuring the ISC value, and is a schematic diagram showing the arrangement of a light source, a measurement sample, a screen, and a CCD camera as viewed from above. As shown in FIG. 4, a light source L, three first stacked units 100, and a screen S were arranged in this order, and a transmitted image projected onto the screen S was measured by a CCD camera C. The measurement sample was an assembly of three first laminated units 100 arranged side by side. The three first laminated units 100 were arranged with a gap of 0.001 to 3 mm between them. As shown in FIG. 4, the first laminated unit 100 closest to the light source L was positioned so that the adjacent glass plate G was located on the light source L side. The first laminated unit 100 located in the middle was positioned so that the adjacent glass plate G was located on the screen S side. The first laminated unit 100 closest to the screen S was positioned so that the adjacent glass plate G was located on the light source L side. The distance from the light source L to the measurement sample in the X-axis direction was set to 10 to 60 cm. The distance from the light source L to the screen S in the X-axis direction was set to 70 to 130 cm. The distance from the CCD camera C to the measurement sample in the Y-axis direction was set to 3 to 30 cm. The distance from the CCD camera C to the screen S in the X-axis direction was set to 70 to 130 cm. For clarity, the details of the first laminated portion are omitted in Figure 4. The measurement results are shown in Table 1.

[0085] For the examples and comparative examples, appearance (light transmitted through the lens) was evaluated using an optical lens (manufactured by Thorabs, product name "LA1145") and a point light source (manufactured by Hamamatsu Photonics, model number "L8425-01"). Specifically, the first and second laminated parts, cut into 45 mm diameter circles, were laminated onto the flat side of the optical lens while gently pressing with a hand roller, in that order, to prevent the inclusion of foreign matter, air bubbles, or deformation streaks on the surface. Next, to remove the effects of minute air bubbles, degassing was performed using a pressure degassing device (autoclave). The degassing conditions were 50°C, 0.5 MPa, and 30 minutes. After degassing, the sample was allowed to cool at room temperature for at least 30 minutes to obtain a measurement sample. A point light source, an optical lens (measurement sample), and a screen were placed in this order, and the light from the point light source was projected onto the screen through the optical lens to evaluate its appearance. The lens was held by a holder at a position where the light from the point light source was incident on the convex side of the optical lens. The distance from the point light source to the screen was 1050 mm, and the distance from the optical lens to the screen was 130 mm. The light projected onto the screen through the optical lens was visually observed, and the appearance was evaluated according to the following criteria. The measurement results are shown in Table 1. (Evaluation criteria) Good: No visible wrinkles or ripples Poor: Wrinkles and ripples are visible

[0086] [Table 1]

[0087] The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations shown in the above-described embodiment can be replaced with configurations that are substantially the same as those shown in the above-described embodiment, that have the same effects, or that can achieve the same purpose. [Industrial Applicability]

[0088] The lens unit according to the embodiment of the present invention can be used in a display such as VR goggles, for example. [Explanation of symbols]

[0089] 2 display system, 4 lens portion, 12 display element, 14 reflective polarizing element, 16 first lens portion, 18 half mirror, 20 first phase difference element, 22 second phase difference element, 24 second lens portion, 28 absorptive polarizing element, 30 third phase difference element, 31 first protective member, 32 second protective member, 41 adhesive layer, 42 adhesive layer, 43 adhesive layer, 44 adhesive layer, 45 adhesive layer, 46 adhesive layer, 100 first laminate portion, 200 second laminate portion.

Claims

1. An optical member set including a polarizing member, a first lambda / 4 member, a second lambda / 4 member, and a first laminated portion including at least one pressure-sensitive adhesive layer, and a reflective polarizing member, The respective members included in the optical member set are arranged so that light emitted forward from the display element passes through the polarizing member, the first λ / 4 member, the first lens unit, and the first stacked unit in this order, is reflected by the reflective polarizing member, passes through the first stacked unit, is reflected forward, and passes through the first stacked unit, the reflective polarizing member, and the second lens unit in this order; The ISC value of an assembly formed by arranging three of the first laminated units is 100 or less. Optical component set.

2. The optical member set according to claim 1 , further comprising a second stacked portion including the reflective polarizing member.

3. The optical member set according to claim 2 , wherein the first laminated portion and the second laminated portion are spaced apart from each other.

4. The optical member set according to claim 2 , wherein the second stacked portion includes an absorptive polarizing member disposed between the reflective polarizing member and the second lens portion.

5. The optical member set according to claim 2 , wherein the second stacked portion includes a third λ / 4 member disposed between the reflective polarizing member and the second lens portion.

6. The optical member set according to claim 1 , wherein the first stacked portion includes a first protective member disposed in front of the second λ / 4 member.

7. The optical member set according to claim 1 , wherein the first laminated portion includes three or less pressure-sensitive adhesive layers.

8. The optical member set according to claim 1 , wherein each of the pressure-sensitive adhesive layers included in the first laminated portion has a thickness of 20 μm or less.

9. The optical member set according to claim 1 , wherein each of the pressure-sensitive adhesive layers included in the first laminated portion has a surface roughness Ra of 20 nm or less.

10. The optical member set according to claim 1 , wherein each of the pressure-sensitive adhesive layers included in the first laminated portion is a single layer.

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