JP2024095083A - Lens and laminated film - Google Patents

Abstract

[Problem] To provide a lens section that can realize weight reduction and improved visibility of VR goggles. [Solution] The goggles include a reflective polarizing member that reflects light emitted forward from a display element and passed through a polarizing member and a first λ/4 member, a first lens section disposed between the display element and the reflective polarizing member, a half mirror that is disposed between the display element and the first lens section, transmits the light emitted from the display element and reflects the light reflected by the reflective polarizing member toward the reflective polarizing member, a second lens section disposed in front of the reflective polarizing member, a second λ/4 member disposed between the half mirror and the reflective polarizing member, and a first protective member and a second protective member disposed between the half mirror and the reflective polarizing member, the first protective member and the second protective member being disposed opposite each other via a space, and each having a maximum value of 1.2% or less in a 5° regular reflectance spectrum in a wavelength range of 420 nm to 680 nm. [Selected Figure] Figure 1

Description

The present invention relates to a lens portion and a laminated film.

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 image display performance (see, for example, Patent Document 1).

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. Since 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 making the lenses used in VR goggles thinner. On the other hand, there is also a demand for the development of optical components suitable for display systems using thin lenses. For example, there is a demand for optical components that can solve the problem of reflections that can occur inside VR goggles in order to improve visibility.

JP 2021-103286 A

In view of the above, the primary objective of the present invention is to provide a lens section that can reduce the weight of VR goggles and improve visibility.

1. The lens unit according to an embodiment of the present invention is a lens unit used in a display system that displays an image to a user, comprising: a reflective polarizing element that reflects light that is emitted forward from a display surface of a display element that displays an image and passes through a polarizing element and a first λ/4 element; a first lens unit that is disposed on an optical path between the display element and the reflective polarizing element; a half mirror that is disposed between the display element and the first lens unit, transmits the light emitted from the display element, and reflects the light reflected by the reflective polarizing element toward the reflective polarizing element; a second lens unit that is disposed in front of the reflective polarizing element; a second λ/4 element that is disposed on an optical path between the half mirror and the reflective polarizing element; and a first protective element and a second protective element that are disposed on an optical path between the half mirror and the reflective polarizing element, the first protective element and the second protective element being disposed opposite each other via a space, and the first protective element and the second protective element each have a maximum value of 1.2% or less of a 5° regular reflectance spectrum in a wavelength range of 420 nm to 680 nm.
2. In the lens portion described in 1 above, the first protective member and the second protective member may each have a 5° regular reflectance at a wavelength of 450 nm of 0.3% or less.
3. In the lens portion described in 1 or 2 above, the first protective member and the second protective member may each have a 5° regular reflectance at a wavelength of 600 nm of 0.3% or less.
4. In the lens portion described in any one of 1 to 3 above, the first protective member and the second protective member may each have a surface smoothness of 0.5 arcmin or less.
5. In the lens portion described in any one of 1 to 4 above, the second λ/4 member may satisfy Re(450)<Re(550).
6. The lens unit described in any one of 1 to 5 above may include a first stacked unit including the second λ/4 member and the first protective member, and a second stacked unit including the reflective polarizing member and the second protective member.
7. In the lens portion described in 6 above, the second stacked portion may include an absorptive polarizing member disposed between the reflective polarizing member and the second lens portion.
8. In the lens portion according to the above 6 or 7, the second stacked portion may include a third λ/4 member disposed between the reflective polarizing member and the second lens portion.
9. In the lens portion described in 8 above, the third λ/4 member may satisfy Re(450)<Re(550).
10. The laminated film according to an embodiment of the present invention is used in a display method having a step of passing light representing an image emitted through a polarizing member and a first λ/4 member through a half mirror and a first lens unit, a step of passing the light that has passed through the half mirror and the first lens unit through a second λ/4 member, a step of reflecting the light that has passed through the second λ/4 member toward the half mirror with a reflective polarizing member, a step of making the light reflected by the reflective polarizing member and the half mirror transmittable through the reflective polarizing member by the second λ/4 member, and a step of passing the light that has transmitted through the reflective polarizing member through a second lens unit, and is disposed on the optical path between the half mirror and the reflective polarizing member and is in contact with the space formed between the first lens unit and the second lens unit, and the maximum value of the 5° regular reflectance spectrum in the wavelength range of 420 nm to 680 nm is 1.2% or less.

The lens portion according to the embodiment of the present invention can reduce the weight of VR goggles and improve visibility.

1 is a schematic diagram showing a general configuration of a display system according to an embodiment of the present invention. 2 is a schematic cross-sectional view showing an example of details of a lens portion of the display system shown in FIG. 1 . 1 is a schematic cross-sectional view showing an outline of a laminated film according to one embodiment of the present invention. FIG. 2 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. 1 is a graph showing the 5° regular reflectance spectra of the laminate films of Example 1 and Comparative Example 1. Photographs (a), (b), and (c) show the results of the appearance evaluation. Photographs showing the results of the appearance evaluation are shown in (a), (b), (c) and (d).

Below, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to these embodiments. In order to make the description clearer, the drawings may show the width, thickness, shape, etc. of each part more diagrammatically than the embodiments, but these are merely examples and do not limit the interpretation of the present invention. In addition, in the drawings, the same or equivalent elements are given the same reference numerals, and duplicate descriptions may be omitted.

(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 maximum (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 retardation (Re)
"Re(λ)" is the in-plane retardation measured with light having a wavelength of λ nm at 23° C. For example, "Re(550)" is the in-plane retardation measured with light having a wavelength of 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 having a wavelength of λ nm at 23° C. For example, "Rth(550)" is the retardation in the thickness direction measured with light having a wavelength of 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 referring to an angle in this specification, the angle includes both clockwise and counterclockwise angles with respect to a reference direction. Thus, for example, "45°" means ±45°.

Figure 1 is a schematic diagram showing the general configuration of a display system according to one embodiment of the present invention. In Figure 1, the arrangement and shape of each component of the display system 2 are illustrated. The display system 2 includes a display element 12, a reflective polarizing member 14, a first lens unit 16, a half mirror 18, a first phase difference member 20, a second phase difference member 22, and a second lens unit 24. The reflective polarizing member 14 is disposed in front of the display surface 12a side 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 member 14, and the half mirror 18 is disposed between the display element 12 and the first lens unit 16. The first phase difference member 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second phase difference member 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing member 14.

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).

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 a first linearly polarized light.

The first phase difference member 20 includes a first λ/4 member that can convert the first linearly polarized light incident on the first phase difference member 20 into a 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.

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

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. If 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 portion 16.

The first circularly polarized light emitted from the first λ/4 member included in the first phase difference member 20 passes through the half mirror 18 and the first lens portion 16, and is converted into the second linearly polarized light by the second λ/4 member included in the second phase difference member 22. The second linearly polarized light emitted from the second λ/4 member is reflected toward 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 the same 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.

The second linearly polarized light reflected by the reflective polarizing element 14 is converted into the second circularly polarized light by the second λ/4 element included in the second phase difference element 22, and the second circularly polarized light emitted 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 the third linearly polarized light by the second λ/4 element included in the second phase difference element 22. The third linearly polarized light passes 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 passes through the reflective polarizing element 14.

The light transmitted through the reflective polarizing element 14 passes through the second lens portion 24 and enters the user's eye 26.

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 arranged substantially parallel to each other or substantially perpendicular to each other. The angle 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 phase difference member 20 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 included in the display element 12 and the slow axis of the second λ/4 member included in the second phase difference member 22 is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°.

The in-plane retardation Re(550) of the first λ/4 member is, for example, 100 nm to 190 nm, and may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The first λ/4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The Re(450)/Re(550) of the first 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 in-plane retardation Re(550) of the second λ/4 member is, for example, 100 nm to 190 nm, and may be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The second λ/4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. The Re(450)/Re(550) of the second 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.

In the lens portion 4, a space may be formed between the first lens portion 16 and the second lens portion 24. In this case, it is preferable that the member disposed between the first lens portion 16 and the second lens portion 24 is integrally provided with either the first lens portion 16 or the second lens portion 24. For example, it is preferable that the member disposed between the first lens portion 16 and the second lens portion 24 is integrated with either the first lens portion 16 or the second lens portion 24 via an adhesive layer. According to such a configuration, for example, each member may be excellent in ease of handling. 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.

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

The first laminated unit 100 includes a second phase difference member 22 and an adhesive layer (e.g., a pressure-sensitive adhesive layer) 41 disposed between the first lens unit 16 and the second phase difference member 22, and is integrally provided to 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 phase difference member 22. The first protective member 31 is laminated to the second phase difference member 22 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 42. The first protective member 31 may be located on the outermost surface of the first laminated unit 100.

2, the second phase difference member 22 includes, in addition to the second λ/4 member 22a, a member (so-called positive C plate) 22b whose refractive index characteristics can show the relationship nz>nx=ny. The second phase difference member 22 has a laminated structure of the second λ/4 member 22a and the positive C plate 22b. By using the positive C plate, it is possible to prevent light leakage (for example, light leakage in an oblique direction). As shown in FIG. 2, in the second phase difference member 22, it is preferable that the second λ/4 member 22a is located forward of the positive C plate 22b. The second λ/4 member 22a and the positive C plate 22b are laminated, for example, via an adhesive layer not shown.

The second λ/4 member preferably has a refractive index characteristic that satisfies the relationship nx>ny≧nz. Here, "ny=nz" includes not only the case where ny and nz are completely equal, but also the case where they are substantially equal. Therefore, there may be cases where ny<nz, as long as the effect of the present invention is not impaired. The Nz coefficient of the second 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.

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 resin film or an oriented and solidified layer of a liquid crystal compound.

Examples of resins contained in the resin film include polycarbonate-based resins, polyester carbonate-based resins, polyester-based resins, polyvinyl acetal-based resins, polyarylate-based resins, cyclic olefin-based resins, cellulose-based resins, polyvinyl alcohol-based resins, polyamide-based resins, polyimide-based resins, polyether-based resins, polystyrene-based resins, acrylic-based resins, and the like. These resins may be used alone or in combination. Examples of methods for combining include blending and copolymerization. When the second λ/4 member exhibits reverse dispersion wavelength characteristics, a resin film containing a polycarbonate-based resin or a polyester carbonate-based resin (hereinafter sometimes simply referred to as a polycarbonate-based resin) may be preferably used.

Any suitable polycarbonate-based resin can be used as the polycarbonate-based resin. For example, the polycarbonate-based resin contains a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from at least one dihydroxy compound selected from the group consisting of alicyclic diol, alicyclic dimethanol, di-, tri- or polyethylene glycol, and alkylene glycol or spiro glycol. Preferably, the polycarbonate-based resin contains a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, a structural unit derived from an alicyclic dimethanol and/or a structural unit derived from a di-, tri- or polyethylene glycol; more preferably, it contains a structural unit derived from a fluorene-based dihydroxy compound, a structural unit derived from an isosorbide-based dihydroxy compound, and a structural unit derived from a di-, tri- or polyethylene glycol. The polycarbonate-based resin may contain a structural unit derived from another dihydroxy compound as necessary. Details of polycarbonate-based resins that can be suitably used for 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.

The thickness of the second λ/4 member, which is 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.

The above-mentioned alignment solidified layer of the liquid crystal compound 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 "alignment solidified layer" is a concept that includes an alignment solidified layer obtained by hardening 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.

The alignment solidified layer of the liquid crystal compound (liquid crystal alignment solidified 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 adopted 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 deposition method and photoalignment treatment. Any appropriate conditions can be adopted as the treatment conditions for various alignment treatments depending on the purpose.

The alignment of liquid crystal compounds is achieved by treating them at a temperature that exhibits a liquid crystal phase according to the type of liquid crystal compound. By carrying out such temperature treatment, the liquid crystal compounds take on a liquid crystal state, and the liquid crystal compounds are aligned according to the alignment treatment direction of the substrate surface.

In one embodiment, the alignment state is fixed by cooling the liquid crystal compound aligned as described above. If 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.

As the liquid crystal compound, any suitable liquid crystal polymer and/or liquid crystal monomer can be used. 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, for example, in JP 2006-163343 A, JP 2006-178389 A, and WO 2018/123551 A. The descriptions in these publications are incorporated herein by reference.

The thickness of the second λ/4 member consisting of the 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.

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.

The positive C plate may be made of any suitable material, but is preferably made 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-A-2002-333642. In this case, the thickness of the positive C plate is preferably 0.5 μm to 5 μm.

The first protective member may typically be a laminated film having a substrate and a surface treatment layer. The first protective member having a surface treatment layer may be disposed so that the surface treatment layer is located on the forward side. Specifically, the surface treatment layer may be located on the outermost surface of the first laminated portion.

The first protective member has a maximum value of 0% to 1.2%, preferably 1.0% or less, and more preferably 0.8% or less in the 5° regular reflectance spectrum in the wavelength range of 420 nm to 680 nm. By positioning a protective member having such reflective properties on the outermost surface of the laminated portion, visibility can be significantly improved. Specifically, by the protective member in contact with the space formed between the first lens portion 16 and the second lens portion 24 satisfying the above-mentioned reflective properties, light loss due to reflection at the interface between the air and the protective member can be suppressed extremely well. In the display system 2 using many members, a large amount of light is required, and the effect of suppressing light loss can be significantly obtained. As described above, in the display system 2 shown in FIG. 1, light can pass through the member disposed between the half mirror 18 and the reflective polarizing member 14 three times, so the effect of suppressing light loss can be significantly obtained. In addition, by the protective member satisfying the above-mentioned reflective properties, the visibility of afterimages (ghosts) caused by reflection can be suppressed.

As mentioned above, when a large amount of light is used, hue management can be important. For example, the balance of reflectance in the visible light region can be important. The 5° specular reflectance of the first protective member at a wavelength of 450 nm is, for example, 0.01% or more and 0.4% or less, preferably 0.3% or less, more preferably 0.2% or less, and even more preferably 0.1% or less. The 5° specular reflectance of the first protective member at a wavelength of 600 nm is, for example, 0.01% or more and 0.4% or less, preferably 0.3% or less, more preferably 0.2% or less, and even more preferably 0.1% or less.

The 5° specular reflectance spectrum of the first protective member in the wavelength range of 420 nm to 680 nm may have a minimum value in the wavelength range of 450 nm to 480 nm and in the wavelength range of 600 nm to 630 nm. For example, the ratio of the average value Ave (450-480 nm) of the 5° specular reflectance in the wavelength range of 450 nm to 480 nm to the average value Ave (530-560 nm) of the 5° specular reflectance in the wavelength range of 530 nm to 560 nm is preferably 0.10 or more and 0.90 or less, more preferably 0.80 or less. And, the ratio of the average value Ave (600-630 nm) of the 5° specular reflectance in the wavelength range of 600 nm to 630 nm to the average value Ave (530-560 nm) of the 5° specular reflectance in the wavelength range of 530 nm to 560 nm is preferably 0.10 or more and 0.50 or less, more preferably 0.40 or less. The average 5° specular reflectance can be calculated, for example, by extracting seven measured values at 5 nm intervals in each wavelength range and dividing the sum of these by the number of wavelengths extracted (7 points).

The surface smoothness of the first protective member is preferably 0.5 arcmin or less, and more preferably 0.4 arcmin or less. By using a protective member that satisfies such smoothness, it is possible to suppress the generation of diffused light and prevent the image from becoming unclear. In practice, the surface smoothness of the first protective member is, for example, 0.1 arcmin or more. The thickness of the first protective member is preferably 10 μm to 80 μm, more preferably 15 μm to 60 μm, and even more preferably 20 μm to 45 μm.

Figure 3 is a schematic cross-sectional view showing the general configuration of a laminated film according to one embodiment of the present invention. The laminated film 34 has a substrate 36 and a surface treatment layer 38 disposed above the substrate 36. The thickness of the substrate 36 is preferably 5 μm to 80 μm, more preferably 10 μm to 50 μm, and even more preferably 15 μm to 40 μm. The surface smoothness of the substrate 36 is preferably 0.7 arcmin or less, more preferably 0.6 arcmin or less, and even more preferably 0.5 arcmin or less. The surface smoothness can be measured by focusing irradiated light on the surface of the object.

The substrate 36 may be made of any suitable film. Examples of materials that are the main components of the film that constitutes the substrate 36 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 such as polynorbornene, polyolefin-based, (meth)acrylic, acetate-based, and other resins. Here, (meth)acrylic refers to acrylic and/or methacrylic. In one embodiment, the substrate 36 is preferably made of a (meth)acrylic resin. By employing a (meth)acrylic resin, the above-mentioned surface smoothness can be satisfactorily satisfied. Specifically, by employing a (meth)acrylic resin, a substrate with excellent surface smoothness can be formed by extrusion molding.

The thickness of the surface treatment layer 38 is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm. The surface treatment layer 38 has, for example, a hard coat layer 38a and a functional layer 38b having an anti-reflection function.

The hard coat layer 38a is typically formed by applying a hard coat layer-forming material to the substrate 36 and curing the applied layer. The hard coat layer-forming material typically includes a curable compound as a layer-forming component. Examples of the curing mechanism of the curable compound include a thermosetting type and a photocurable type. Examples of the curable compound include a monomer, an oligomer, and a prepolymer. Preferably, a polyfunctional monomer or oligomer is used as the curable compound. Examples of the polyfunctional monomer or oligomer include a monomer or oligomer having two or more (meth)acryloyl groups, a urethane (meth)acrylate or an oligomer of a urethane (meth)acrylate, an epoxy-based monomer or oligomer, and a silicone-based monomer or oligomer.

The thickness of the hard coat layer 38a is preferably 0.5 μm to 10 μm, more preferably 1 μm to 7 μm, and even more preferably 2 μm to 5 μm.

It is preferable that the functional layer 38b has a laminated structure including a high refractive index layer and a low refractive index layer. It is preferable that the functional layer 38b has a high refractive index layer and a low refractive index layer in this order from the substrate 36 side. By having such a laminated structure, the above reflection characteristics can be satisfactorily satisfied.

For example, the high refractive index layer may be made of a high refractive index resin (e.g., a refractive index of 1.55 or more measured at a wavelength of 550 nm). In this case, the high refractive index layer may be a coating layer. In addition, for example, the high refractive index layer may be made of an inorganic film. In this case, the high refractive index layer may be formed by physical vapor deposition such as vacuum deposition or sputtering, or chemical vapor deposition.

The thickness of the high refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.

The thickness of the low refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.

The low refractive index layer (anti-reflection layer) can be obtained, for example, by applying a coating liquid for forming a low refractive index layer (anti-reflection layer), drying the resulting coating film, and curing the resulting coating film. The coating liquid for forming an anti-reflection layer may contain, for example, a resin component (curable compound), a fluorine-containing additive, hollow particles, solid particles, a solvent, and the like, and can be obtained, for example, by mixing these.

The curing mechanism of the resin component (curable compound) contained in the coating liquid for forming the anti-reflection layer can be, for example, a heat curing type or a light curing type. For example, a curable compound having at least one of an acrylate group and a methacrylate group is used as the resin component, and examples thereof include oligomers or prepolymers such as acrylates and methacrylates of polyfunctional compounds such as silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiolpolyene resins, and polyhydric alcohols. These may be used alone or in combination of two or more types.

The resin component may be, for example, a reactive diluent having at least one of an acrylate group and a methacrylate group. The reactive diluent may be, for example, a reactive diluent described in JP-A-2008-88309, and may include, for example, a monofunctional acrylate, a monofunctional methacrylate, a polyfunctional acrylate, a polyfunctional methacrylate, etc. As the reactive diluent, from the viewpoint of obtaining excellent hardness, a trifunctional or higher acrylate or a trifunctional or higher methacrylate is preferably used. As the reactive diluent, for example, butanediol glycerin ether diacrylate, an acrylate of isocyanuric acid, a methacrylate of isocyanuric acid, etc. may be mentioned. These may be used alone or in combination of two or more. For example, a curing agent may be used to harden the resin component. As the curing agent, for example, a known polymerization initiator (for example, a thermal polymerization initiator, a photopolymerization initiator, etc.) may be used.

The fluorine-containing additive may be, for example, an organic compound containing fluorine, or an inorganic compound containing fluorine. Examples of the organic compound containing fluorine include a fluorine-containing antifouling coating agent, a fluorine-containing acrylic compound, and a fluorine-silicon-containing acrylic compound. A commercially available product may be used as the organic compound containing fluorine. Specific examples of commercially available products include "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd. and "Megafac" manufactured by DIC Corporation. The content of the fluorine-containing additive may be, for example, 0.05 parts by weight or more, 0.1 parts by weight or more, 0.15 parts by weight or more, 0.20 parts by weight or more, or 0.25 parts by weight or more, or 20 parts by weight or less, 15 parts by weight or less, 10 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less, relative to 100 parts by weight of the resin component.

As the hollow particles, for example, silica particles, acrylic particles, and acrylic-styrene copolymer particles are used. As the hollow silica particles, commercially available products (for example, trade names "Suluria 5320" and "Suluria 4320" manufactured by JGC Catalysts and Chemicals Co., Ltd.) can be used. The weight average particle diameter of the hollow particles may be, for example, 30 nm or more, 40 nm or more, 50 nm or more, 60 nm or more, or 70 nm or more, or 150 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, or 110 nm or less. The shape of the hollow particles is not particularly limited, but is preferably approximately spherical. Specifically, the aspect ratio of the hollow particles is preferably 1.5 or less. The content of hollow particles may be, for example, 30 parts by weight or more, 50 parts by weight or more, 70 parts by weight or more, 90 parts by weight or more, or 100 parts by weight or more, or 300 parts by weight or less, 270 parts by weight or less, 250 parts by weight or less, 200 parts by weight or less, or 180 parts by weight or less, relative to 100 parts by weight of the resin component.

As the solid particles, for example, silica particles, zirconia particles, and titania particles are used. As the solid silica particles, commercially available products (for example, products manufactured by Nissan Chemical Industries, Ltd. under the trade names "MEK-2140Z-AC", "MIBK-ST", and "IPA-ST") can be used. The weight average particle diameter of the solid particles may be, for example, 5 nm or more, 10 nm or more, 15 nm or more, 20 nm or more, or 25 nm or more, and may be 330 nm or less, 250 nm or less, 200 nm or less, 150 nm or less, or 100 nm or less. The shape of the hollow particles is not particularly limited, but is preferably approximately spherical. Specifically, the aspect ratio of the hollow particles is preferably 1.5 or less. The content of the solid particles may be, for example, 5 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, 20 parts by weight or more, or 25 parts by weight or more, or 150 parts by weight or less, 120 parts by weight or less, 100 parts by weight or less, or 80 parts by weight or less, relative to 100 parts by weight of the resin component.

Any suitable solvent may be used as the solvent. Examples of the solvent include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, TBA (tertiary butyl alcohol), and 2-methoxyethanol; ketones such as acetone, methyl ethyl ketone, MIBK (methyl isobutyl ketone), and cyclopentanone; esters such as methyl acetate, ethyl acetate, butyl acetate, and PMA (propylene glycol monomethyl ether acetate); ethers such as diisopropyl ether and propylene glycol monomethyl ether; glycols such as ethylene glycol and propylene glycol; cellosolves such as ethyl cellosolve and butyl cellosolve; aliphatic hydrocarbons such as hexane, heptane, and octane; and aromatic hydrocarbons such as benzene, toluene, and xylene. These may be used alone or in combination of two or more types. The content of the solvent may be, for example, such that the weight of the solid content relative to the total weight of the coating liquid for forming the anti-reflection layer is, for example, 0.1 wt % or more, 0.3 wt % or more, 0.5 wt % or more, 1.0 wt % or more, or 1.5 wt % or more, or 20 wt % or less, 15 wt % or less, 10 wt % or less, 5 wt % or less, or 3 wt % or less.

The coating liquid for forming the anti-reflection layer can be applied by known coating methods such as fountain coating, die coating, spin coating, spray coating, gravure coating, roll coating, and bar coating. The drying temperature of the coating is, for example, 30°C to 200°C, and the drying time is, for example, 30 seconds to 90 seconds. The coating can be cured by, for example, heating or light irradiation (typically, ultraviolet irradiation). A high-pressure mercury lamp is used as a light source for light irradiation. The dose of ultraviolet irradiation is preferably 50 mJ/cm ² to 500 mJ/cm ² as the cumulative exposure dose at an ultraviolet wavelength of 365 nm.

The second laminated section 200 includes a reflective polarizing member 14 and an adhesive layer (e.g., a pressure-sensitive adhesive layer) disposed between the reflective polarizing member 14 and the second lens section 24. The second laminated section 200 further includes an absorbing polarizing member 28 disposed between the reflective polarizing member 14 and the second lens section 24, for example, from the viewpoint of improving visibility. The absorbing polarizing member 28 is laminated in front of the reflective polarizing member 14 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 44. The reflection axis of the reflective polarizing member 14 and the absorption axis of the absorbing polarizing member 28 can be disposed approximately parallel to each other, and the transmission axis of the reflective polarizing member 14 and the transmission axis of the absorbing polarizing member 28 can be disposed approximately parallel to each other. By laminating them via an adhesive layer, the reflective polarizing member 14 and the absorbing polarizing member 28 are fixed, and it is possible to prevent the axial arrangement of the reflection axis and the absorption axis (transmission axis and transmission axis) from being misaligned. In addition, it is possible to suppress the adverse effects of an air layer that may form between the reflective polarizing element 14 and the absorptive polarizing element 28.

The second laminated section 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 (e.g., a pressure-sensitive adhesive layer) 43. The second protective member 32 may be located on the outermost surface of the second laminated section 200. The first protective member 31 and the second protective member 32 are disposed opposite each other with a space therebetween. The second protective member may be a laminated film having a substrate and a surface treatment layer, as with the first protective member. In this case, the surface treatment layer may be located on the outermost surface of the second laminated section. The details of the second protective member may be the same as those of the first protective member. Specifically, the reflection characteristics, effects, smoothness, configuration, thickness, and constituent materials of the second protective member may be the same as those of the first protective member.

In the example shown in FIG. 2, the second laminate 200 further includes a third phase difference member 30 disposed between the absorbing polarizing member 28 and the second lens section 24. The third phase difference member 30 is laminated to the absorbing polarizing member 28 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 45. The third phase difference member 30 is also laminated to the second lens section 24 via an adhesive layer (e.g., a pressure-sensitive adhesive layer) 46, and the second laminate 200 is integrally provided to the second lens section 24. The third phase difference member 30 includes, for example, a third λ/4 member. The angle between the absorption axis of the absorbing 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 about 45°. By providing such a member, for example, reflection of external light from the second lens section 16 side can be prevented. 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.

The reflective polarizing element can transmit light polarized parallel to its transmission axis (typically, linearly polarized light) while maintaining its polarization state, and can reflect light in other polarization states. A typical reflective polarizing element is made of a film (sometimes called a reflective polarizing film) with 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.

Figure 4 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 14a has alternating layers A having birefringence and layers B having 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 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 layers A and 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 layers A and B in the x-axis direction is preferably 0.2 to 0.3.

The A layer is typically made of a material that exhibits birefringence when stretched. Examples of such materials include naphthalene dicarboxylic 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 even when stretched. Examples of such materials include copolyesters of naphthalene dicarboxylic acid and terephthalic acid. The multilayer structure can be formed by combining coextrusion and stretching. For example, the material constituting the A layer and the material constituting 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 can correspond to the stretching direction.

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

The crossed transmittance (Tc) of the reflective polarizing member (reflective polarizing film) may be, for example, 0.01% to 3%. The single transmittance (Ts) of the reflective polarizing member (reflective polarizing film) may be, for example, 43% to 49%, and 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%.

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 by measuring the single transmittance Ts, parallel transmittance Tp and crossed transmittance Tc using an ultraviolet-visible spectrophotometer, and using the obtained Tp and Tc, according to 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 visibility.
Degree of polarization P(%)={(Tp-Tc)/(Tp+Tc)} ^1/2 × 100

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, and 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.

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.

When producing from a single-layer resin film, for example, an absorptive polarizing film can be obtained by subjecting a hydrophilic polymer film such as a polyvinyl alcohol (PVA)-based film, a partially formalized PVA-based film, or an ethylene-vinyl acetate copolymer-based partially saponified film to a dyeing process using a dichroic substance such as iodine or a dichroic dye, a stretching process, or the like. Among these, an absorptive polarizing film obtained by dyeing a PVA-based film with iodine and stretching it uniaxially is preferred.

The dyeing with iodine is carried out, for example, by immersing the PVA-based 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 process, or may be carried out while dyeing. Alternatively, the film may be stretched and then dyed. If necessary, the PVA-based film may be subjected to a swelling process, a crosslinking process, a washing process, a drying process, etc.

Examples of the laminate produced using the above-mentioned 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 coated on the resin substrate. The absorptive polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated 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 to obtain a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to make the PVA-based resin layer into an absorptive 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. The stretching typically includes immersing the laminate in an aqueous boric acid solution to stretch it. Furthermore, the stretching may further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the boric acid aqueous solution, if necessary. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which the laminate is heated while being conveyed 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 air-assisted stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment in this order. By introducing the auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is applied onto a thermoplastic resin, and it is possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, problems such as a decrease in the orientation of PVA or dissolution can be prevented when the PVA is immersed in water in the subsequent dyeing step or stretching step, and it is 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 a halide. This can improve the optical properties of the absorptive polarizing film obtained by immersing the laminate in a liquid in a treatment process such as a dyeing process and an underwater stretching process. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction by a drying shrinkage process. The obtained resin substrate/absorptive polarizing film laminate may be used as it 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 on the peeled 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 the manufacturing method of such an absorptive polarizing film are described in, for example, JP 2012-73580 A and JP 6470455 A. The entire disclosures of these publications are incorporated herein by reference.

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 degree of polarization (P) of the absorptive polarizing element (absorptive polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

The in-plane retardation Re(550) of the third 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. The third λ/4 member preferably exhibits an inverse dispersion wavelength characteristic 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 third λ/4 member preferably exhibits a refractive index characteristic of 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.

The third λ/4 member is formed of any suitable 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 the third λ/4 member composed 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.

The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. The thickness and surface smoothness are values measured by the following measuring methods. Furthermore, unless otherwise specified, "parts" and "%" are based on weight.
<Thickness>
The thickness of 10 μm or less was measured using a scanning electron microscope (manufactured by JEOL Ltd., product name "JSM-7100F"), and the thickness of more than 10 μm was measured using a digital micrometer (manufactured by Anritsu Corporation, product name "KC-351C").
<Surface smoothness>
The surface smoothness was measured using a scanning white light interferometer (manufactured by Zygo, product name "NewView9000"). Specifically, the measurement sample was placed on a measurement table with a vibration-proof table, interference fringes were generated using a single white LED illumination, and an interference objective lens (1.4 times) with a reference surface was scanned in the Z direction (thickness direction) to selectively obtain the smoothness (surface smoothness) of the outermost surface of the measurement target in the field of view of 12.4 mm□. A 5 μm thick acrylic adhesive layer with little unevenness was formed on a microslide glass (manufactured by Matsunami Glass Industry, product name "S200200"), and the film to be measured was laminated on this adhesive surface so that foreign matter, air bubbles, and deformation lines would not get in, and the smoothness of the surface opposite to the adhesive layer was measured.
For the analysis, the surface smoothness (unit: arcmin) was defined as a value obtained by multiplying the angle index "slope magnitude RMS" (corresponding to 2σ).

[Example 1]
(Preparation of 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 mainly composed of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1 part of a leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100") and 3 parts of a photopolymerization initiator (manufactured by Ciba Japan KK, "Irgacure 907") and diluting with methyl isobutyl ketone to a solids concentration of 50%.

(Preparation of Coating Solution for Forming High Refractive Index Layer)
100 parts by weight of a multifunctional acrylate (manufactured by Arakawa Chemical Industries, Ltd., product name "Opstar KZ6728", solid content 20% by weight), 3 parts by weight of a leveling agent (manufactured by DIC Corporation, product name "GRANDIC PC4100"), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF Corporation, product name "OMNIRAD907", solid content 100% by weight) were mixed. The mixture was diluted with butyl acetate as a diluting solvent to a solid content of 12% by weight, and stirred to prepare a coating liquid for forming a high refractive index layer.

(Preparation of Coating Solution A for Forming Low Refractive Index Layer)
100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as a main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300", solid content 100% by weight), 150 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Co., Ltd., product name "Surulia 5320", solid content 20% by weight, weight average particle diameter 75 nm), 50 parts by weight of solid nanosilica particles (manufactured by Nissan Chemical Industries, Ltd., product name "MEK-2140Z-AC", solid content 30% by weight, weight average particle diameter 10 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KY-1203", solid content 20% by weight), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "OMNIRAD907", solid content 100% by weight) were mixed. To the mixture was added 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 as a dilution solvent until the total solids content became 4% by weight, and the mixture was stirred to prepare a coating liquid for forming a low refractive index layer.

The above hard coat layer-forming material was applied to an acrylic film (thickness 40 μm, surface smoothness 0.45 arcmin) having a lactone ring structure, and heated at 90° C. for 1 minute. The coated layer after heating was irradiated with ultraviolet light from a high-pressure mercury lamp at an integrated light quantity of 300 mJ/ ^cm2 to harden the coated layer, thereby producing an acrylic film (thickness 44 μm, surface smoothness on the hard coat layer side 0.4 arcmin) on which a hard coat layer having a thickness of 4 μm was formed.
Next, the coating solution for forming the high refractive index layer was applied onto the hard coat layer with 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 ultraviolet light from a high pressure mercury lamp at an integrated light quantity of 300 mJ/cm ² to cure the coating film, forming a high refractive index layer with a thickness of 140 nm.
Next, the low refractive index layer-forming coating liquid was applied onto the high refractive index layer with a wire bar, and the applied coating liquid was heated at 80° C. for 1 minute and dried to form a coating film. The dried coating film was irradiated with ultraviolet light from a high pressure mercury lamp at an integrated light quantity of 300 mJ/cm ² to cure the coating film, forming a low refractive index layer with a thickness of 105 nm.
In this way, a laminated film having a thickness of 44 μm and a surface smoothness of 0.4 arcmin was obtained.

[Comparative Example 1]
A laminate film having a thickness of 44 μm and a surface smoothness of 0.4 arcmin was obtained in the same manner as in Example 1, except that a high refractive index layer was not formed and a low refractive index layer having a thickness of 100 nm was formed using the following coating liquid B as a coating liquid for forming a low refractive index layer.

(Preparation of Coating Solution B for Forming Low Refractive Index Layer)
100 parts by weight of a polyfunctional acrylate containing pentaerythritol triacrylate as a main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscoat #300", solid content 100% by weight), 100 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts and Chemicals Industries Co., Ltd., product name "Surulia 5320", solid content 20% by weight, weight average particle size 75 nm), 12 parts by weight of a fluorine-containing additive (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KY-1203", solid content 20% by weight), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, product name "OMNIRAD907", solid content 100% by weight) were mixed. To the 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 so that the total solid content became 4% by weight, and the mixture was stirred to prepare coating solution B for forming an anti-reflective low refractive layer.

[Comparative Example 2]
A laminated film having a thickness of 44 μm and a surface smoothness of 0.4 arcmin was obtained in the same manner as in Example 1, except that the high refractive index layer and the low refractive index layer were not formed.

<Evaluation>
(1) 5° Regular Reflectance A test piece of 50 mm×50 mm size was cut out from each of the laminated films of Example 1, Comparative Example 1, and Comparative Example 2, and attached to a black acrylic plate using an adhesive to obtain a measurement sample. A spectrophotometer (manufactured by Hitachi High-Technologies Corporation, product name "U-4100") was used as the measurement device to measure the regular reflectance spectrum. The measurement wavelength was in the range of 420 nm to 680 nm, and the incident angle of light to the measurement sample was 5°.

The 5° specular reflectance spectra of the laminated films of Example 1 and Comparative Example 1 are shown in Figure 5. As shown in Figure 5, the maximum value of the 5° specular reflectance spectrum of the laminated film of Example 1 in the wavelength range of 420 nm to 680 nm was 0.75%. In addition, the 5° specular reflectance at a wavelength of 450 nm was 0.17%, and the 5° specular reflectance at a wavelength of 600 nm was 0.05%. The results of Comparative Example 1 and Comparative Example 2 are as follows.

(2) Appearance 1
The laminated films of Example 1, Comparative Example 1, and Comparative Example 2 were attached to a black acrylic plate using an adhesive to obtain a measurement plate. In a dark room, the appearance (reflection appearance) of the measurement plate was visually confirmed when light was irradiated from a surface light emitting unit (manufactured by AItec, LED lighting box "LLBK1") installed 18 cm away from the measurement plate and facing the measurement plate, using a dimming volume 1. The reflection appearance is shown in Figures 6(a), 6(b), and 6(c). Specifically, Figure 6(a) shows the result when white display light was irradiated, Figure 6(b) shows the result when blue light (wavelength 450 nm ± 30 nm) was irradiated, and Figure 6(c) shows the result when red light (wavelength 630 nm ± 30 nm) was irradiated.

(3) Appearance 2
The laminated films of Example 1, Comparative Example 1, and Comparative Example 2 were attached to a transparent glass plate using an adhesive to obtain a measurement plate. A surface-emitting unit (manufactured by AItec, LED lighting box "LLBK1") was installed in a darkroom, and the measurement plate was placed on the light-emitting surface. The appearance (transmitted appearance) of the measurement plate when light was irradiated from the surface-emitting unit by the dimming volume 1 was visually confirmed. The transmitted appearance is shown in Figures 7(a), 7(b), 7(c), and 7(d). Figure 7(a) shows the result when white display light was irradiated, Figure 7(b) shows the result when blue light (wavelength 450 nm ± 30 nm) was irradiated, Figure 7(c) shows the result when red light (wavelength 630 nm ± 30 nm) was irradiated, and Figure 7(d) shows the result when green light (wavelength 530 nm ± 30 nm) was irradiated.

As shown in Figures 6(a), 6(b), and 6(c), Example 1 is far superior in reflective appearance compared to Comparative Example 1 and Comparative Example 2. In the above evaluation, a black acrylic plate was used assuming a combination with an absorptive polarizing member, but a similar difference in reflective appearance was confirmed when a transparent glass plate was used. According to Example 1, it is believed that the problem of ghosting that can occur due to reflected light in a display system according to an embodiment of the present invention can be extremely well solved. Note that, as shown in Figures 7(a), 7(b), 7(c), and 7(d), there is no significant difference in transmissive appearance between Example 1, Comparative Example 1, and Comparative Example 2.

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 embodiments can be replaced with configurations that are substantially the same as those shown in the above-described embodiments, that have the same effects, or that can achieve the same purpose.

The lens portion according to the embodiment of the present invention can be used, for example, in a display such as a VR goggle.

2 Display system, 4 Lens section, 12 Display element, 14 Reflective polarizing member, 16 First lens section, 18 Half mirror, 20 First phase difference member, 22 Second phase difference member, 24 Second lens section, 28 Absorptive polarizing member, 30 Third phase difference member, 31 First protective member, 32 Second protective member, 34 Laminated film, 36 Substrate, 38 Surface treatment layer, 41 Adhesive layer, 42 Adhesive layer, 43 Adhesive layer, 44 Adhesive layer, 45 Adhesive layer, 46 Adhesive layer, 100 First laminate section, 200 Second laminate section.

Claims (10)

1. A lens unit for use in a display system for displaying an image to a user, comprising:
a reflective polarizing member that reflects light that is emitted forward from a display surface of a display element that displays an image and that has passed through the polarizing member and the first λ/4 member;
a first lens portion disposed on an optical path between the display element and the reflective polarizing member;
a half mirror disposed between the display element and the first lens portion, the half mirror transmitting light emitted from the display element and reflecting light reflected by the reflective polarizing member toward the reflective polarizing member;
A second lens portion disposed in front of the reflective polarizing member;
a second λ/4 member disposed on an optical path between the half mirror and the reflective polarizing member;
a first protective member and a second protective member disposed on an optical path between the half mirror and the reflective polarizing member;
Equipped with
The first protective member and the second protective member are disposed opposite to each other with a space therebetween,
The first protective member and the second protective member each have a maximum value of a 5° regular reflectance spectrum of 1.2% or less in a wavelength range of 420 nm to 680 nm.
Lens part. The lens portion according to claim 1, wherein the first protective member and the second protective member each have a 5° specular reflectance of 0.3% or less at a wavelength of 450 nm. The lens portion according to claim 1, wherein the first protective member and the second protective member each have a 5° specular reflectance of 0.3% or less at a wavelength of 600 nm. The lens portion according to claim 1, wherein the first protective member and the second protective member each have a surface smoothness of 0.5 arcmin or less. The lens portion according to claim 1, wherein the second λ/4 member satisfies Re(450)<Re(550). a first laminated portion including the second λ/4 member and the first protective member;
A second laminated portion including the reflective polarizing member and the second protective member;
The lens portion of claim 1 , comprising: The lens section according to claim 6, wherein the second laminate section includes an absorptive polarizing member disposed between the reflective polarizing member and the second lens section. The lens section according to claim 6, wherein the second laminate section includes a third λ/4 member disposed between the reflective polarizing member and the second lens section. The lens portion according to claim 8, wherein the third λ/4 member satisfies Re(450)<Re(550). A step of passing light representing an image outputted through the polarizing member and the first λ/4 member through a half mirror and a first lens unit;
A step of passing the light that has passed through the half mirror and the first lens portion through a second λ/4 member;
A step of reflecting the light that has passed through the second λ/4 member toward the half mirror by a reflective polarizing member;
allowing the light reflected by the reflective polarizing member and the half mirror to pass through the reflective polarizing member by the second λ/4 member;
A step of passing the light transmitted through the reflective polarizing member through a second lens portion;
The display method includes:
a laminated film disposed on an optical path between the half mirror and the reflective polarizing member and in contact with a space formed between the first lens portion and the second lens portion,
The maximum value of the 5° regular reflectance spectrum in the wavelength range of 420 nm to 680 nm is 1.2% or less;
Laminated film.

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