Lens section and laminated film
The lens unit in VR goggles addresses weight and visibility issues through a reflective polarizing member and controlled reflectance, optimizing light transmission and reducing internal reflections.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- NITTO DENKO CORP
- Filing Date
- 2022-12-28
- Publication Date
- 2026-06-26
Smart Images
Figure 0007880810000002 
Figure 0007880810000003 
Figure 0007880810000004
Abstract
Description
Technical Field
[0001] The present invention relates to a lens unit and a laminated film.
Background Art
[0002] Image display devices typified by liquid crystal display devices and electroluminescence (EL) display devices (for example, organic EL display devices) have been rapidly spreading. In image display devices, in order to realize image display and improve the performance of image display, generally, optical members such as polarizing members and retardation members are used (for example, see Patent Document 1).
[0003] In recent years, new applications of image display devices have been developed. For example, goggles with a display (VR goggles) for realizing Virtual Reality (VR) have begun to be commercialized. Since VR goggles are being considered for use in various scenarios, weight reduction, improvement of visibility, etc. are desired. Weight reduction can be achieved, for example, by thinning the lenses used in VR goggles. On the other hand, the development of optical members suitable for display systems using thin lenses is also desired. For example, in order to improve visibility, an optical member that can solve the problem of reflection that can occur inside VR goggles is desired.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] In view of the above, the main object of the present invention is to provide a lens unit that can achieve weight reduction and improvement of visibility of VR goggles.
Means for Solving the Problems
[0006] 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, and is emitted forward from a display surface of a display element representing the image, and reflects light that has passed through a polarizing member and a first λ / 4 member. A reflective polarizing member, a first lens unit disposed on an optical path between the display element and the reflective polarizing member, and disposed between the display element and the first lens unit, transmits light emitted from the display element, and reflects light reflected by the reflective polarizing member toward the reflective polarizing member. A half mirror, a second lens unit 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, and a first protective member and a second protective member disposed on an optical path between the half mirror and the reflective polarizing member. The first protective member and the second protective member are disposed to face each other through a space, and the first protective member and the second protective member each have a maximum value of a 5° normal reflectance spectrum in the wavelength range of 420 nm to 680 nm of 1.2% or less. 2. In the lens unit according to 1 above, the first protective member and the second protective member may each have a 5° normal reflectance at a wavelength of 450 nm of 0.3% or less. 3. In the lens unit according to 1 or 2 above, the first protective member and the second protective member may each have a 5° normal reflectance at a wavelength of 600 nm of 0.3% or less. 4. In the lens unit according to 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 unit according to any one of 1 to 4 above, the second λ / 4 member may satisfy Re(450) < Re(550). 6. The lens unit according to any one of 1 to 5 above may include a first laminated portion including the second λ / 4 member and the first protective member, and a second laminated portion including the reflective polarizing member and the second protective member. 7. In the lens unit according to 6 above, the second laminated portion may include an absorptive polarizing member disposed between the reflective polarizing member and the second lens unit. 8. In the lens unit according to 6 or 7 above, the second laminated portion may include a third λ / 4 member disposed between the reflective polarizing member and the second lens unit. 9. In the lens unit according to 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, and includes steps 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; passing the light that has passed through the half mirror and the first lens unit through a second λ / 4 member; reflecting the light that has passed through the second λ / 4 member toward the half mirror with a reflective polarizing member; making the light reflected by the reflective polarizing member and the half mirror transmissible through the reflective polarizing member by the second λ / 4 member; and passing the light that has passed through the reflective polarizing member through a second lens unit. The laminated film is disposed on the optical path between the half mirror and the reflective polarizing member and contacts the space formed between the first lens unit and the second lens unit, and the maximum value of the 5° normal reflectance spectrum in the wavelength range of 420 nm to 680 nm is 1.2% or less.
Effect of the Invention
[0007] According to the lens unit according to an embodiment of the present invention, weight reduction and improved visibility of a VR goggle can be achieved.
Brief Description of the Drawings
[0008] [Figure 1] It is a schematic configuration diagram showing a schematic configuration of a display system according to one embodiment of the present invention. [Figure 2] It is a schematic cross-sectional view showing an example of details of the lens unit of the display system shown in FIG. 1. [Figure 3] It is a schematic cross-sectional view showing a schematic configuration of a laminated film according to one embodiment of the present invention. [Figure 4]This is a schematic perspective view showing an example of a multilayer structure contained in a reflective polarizing film. [Figure 5] This graph shows the 5° specular reflectance spectra of the laminated films of Example 1 and Comparative Example 1. [Figure 6] (a), (b), and (c) are photographs showing the results of the visual evaluation. [Figure 7] (a), (b), (c), and (d) are photographs showing the results of the visual evaluation. [Modes for carrying out the invention]
[0009] Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. While the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the embodiments in order to clarify the explanation, these are merely examples and do not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations may be omitted.
[0010] (Definitions 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 where the refractive index is maximum in the plane (i.e., the slow phase axis direction), "ny" is the refractive index in the direction perpendicular to the slow phase axis in the plane (i.e., the fast phase axis direction), and "nz" is the refractive index in the thickness direction. (2) In-plane phase difference (Re) "Re(λ)" is the in-plane phase difference measured with light of wavelength λnm at 23°C. For example, "Re(550)" is the in-plane phase difference measured with light of wavelength 550nm at 23°C. Re(λ) can be calculated using the formula: Re(λ) = (nx - ny) × d, where d (nm) is the thickness of the layer (film). (3) Phase difference in the thickness direction (Rth) "Rth(λ)" is the phase difference in the thickness direction measured with light of wavelength λ nm at 23°C. For example, "Rth(550)" is the phase difference in the thickness direction measured with light of wavelength 550 nm at 23°C. Rth(λ) can be obtained 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 obtained by Nz = Rth / Re. (5) Angle When referring to an angle in this specification, the angle includes both clockwise and counterclockwise directions with respect to the reference direction. Therefore, for example, "45°" means ±45°.
[0011] FIG. 1 is a schematic diagram showing the schematic configuration of a display system according to an embodiment of the present invention. In FIG. 1, the arrangement and shape of each component of the display system 2 are schematically 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 retardation member 20, a second retardation 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 the 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 retardation member 20 is disposed on the optical path between the display element 12 and the half mirror 18, and the second retardation member 22 is disposed on the optical path between the half mirror 18 and the reflective polarizing member 14.
[0012] The components arranged in front of the half mirror (in the illustrated example, the half mirror 18, the first lens unit 16, the second retardation member 22, the reflective polarizing member 14, and the second lens unit 24) may be collectively referred to as a lens unit (lens unit 4).
[0013] The display element 12 is, for example, a liquid crystal display or an organic EL display, and has a display surface 12a for displaying an image. Light emitted from the display surface 12a passes through a polarizing member (typically a polarizing film) that may be included in the display element 12, and is emitted as first linearly polarized light.
[0014] The first phase difference member 20 includes a first λ / 4 member capable of converting a first linearly polarized light incident on the first phase difference member 20 into a first circularly polarized light. If the first phase difference member does not include any members 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.
[0015] The half mirror 18 transmits light emitted from the display element 12 and reflects the light reflected by the reflective polarizing member 14 back towards the reflective polarizing member 14. The half mirror 18 is integrally provided with the first lens portion 16.
[0016] 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 members 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.
[0017] 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 a 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 towards the half mirror 18 without passing through the reflective polarizing member 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member 14 is in the same direction as the reflection axis of the reflective polarizing member 14. Therefore, the second linearly polarized light incident on the reflective polarizing member 14 is reflected by the reflective polarizing member 14.
[0018] The second linearly polarized light reflected by the reflective polarizing member 14 is converted into a second circularly polarized light by the second λ / 4 member included in the second phase difference member 22. The second circularly polarized light emitted from the second λ / 4 member passes through the first lens portion 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 portion 16 and is converted into a third linearly polarized light by the second λ / 4 member included in the second phase difference member 22. The third linearly polarized light is transmitted through the reflective polarizing member 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member 14 is in the same direction as the transmission axis of the reflective polarizing member 14. Therefore, the third linearly polarized light incident on the reflective polarizing member 14 is transmitted through the reflective polarizing member 14.
[0019] Light that has passed through the reflective polarizing member 14 passes through the second lens portion 24 and enters the user's eye 26.
[0020] 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 orthogonal to each other. The angle between the absorption axis of the polarizing member included in the display element 12 and the lagging 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 lagging 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°.
[0021] The in-plane phase difference Re(550) of the first λ / 4 member is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. Preferably, the first λ / 4 member exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the first λ / 4 member is, for example, 0.75 or more and less than 1, but may also be 0.8 or more and 0.95 or less.
[0022] The in-plane phase difference Re(550) of the second λ / 4 member is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. Preferably, the second λ / 4 member exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the second λ / 4 member is, for example, 0.75 or more and less than 1, but may also be 0.8 or more and 0.95 or less.
[0023] 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. With such a configuration, for example, the handling of each member can be improved. The adhesive layer may be formed of an adhesive or a tack. Specifically, the adhesive layer may be an adhesive layer or a tack layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.
[0024] Figure 2 is a schematic cross-sectional view showing an example of the details of the lens section of the display system shown in Figure 1. Specifically, Figure 2 shows a first lens section, a second lens section, and a member positioned between them. The lens section 4 comprises a first lens section 16, a first laminated section 100 provided adjacent to the first lens section 16, a second lens section 24, and a second laminated section 200 provided adjacent to the second lens section 24. In the example shown in Figure 2, the first laminated section 100 and the second laminated section 200 are spaced apart. Although not shown, a half-mirror may be integrally provided with the first lens section 16.
[0025] The first laminated part 100 includes a second retardation member 22 and an adhesive layer (for example, an adhesive layer) 41 disposed between the first lens part 16 and the second retardation member 22, and is integrally provided on the first lens part 16 by the adhesive layer 41. The first laminated part 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 an adhesive layer (for example, an adhesive layer) 42. The first protective member 31 may be located on the outermost surface of the first laminated part 100.
[0026] 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 whose refractive index characteristics may show the 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. By using the positive C-plate, light leakage (for example, light leakage in an oblique direction) can be prevented. As shown in FIG. 2, in the second retardation member 22, it is preferable that the second λ / 4 member 22a is located in front of the positive C-plate 22b. The second λ / 4 member 22a and the positive C-plate 22b are laminated via an adhesive layer (not shown) for example.
[0027] The above second λ / 4 member preferably shows the refractive index characteristics of nx > ny ≧ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal but also the case where they are substantially equal. Therefore, within a range that does not impair the effects of the present invention, ny < nz may occur. The Nz coefficient of the 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.
[0028] The second λ / 4 member is formed of any suitable material that can satisfy the above characteristics. The second λ / 4 member may be, for example, a stretched film of a resin film or an alignment cured layer of a liquid crystal compound.
[0029] Examples of resins included in the above-mentioned 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, and acrylic resins. These resins may be used individually or in combination. Methods of combination include blending and copolymerization. When the second λ / 4 member exhibits 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 suitably used.
[0030] Any suitable polycarbonate resin can be used as the above-mentioned polycarbonate resin. For example, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanol, di, tri, or polyethylene glycol, and alkylene glycol or spiroglycol. Preferably, the polycarbonate resin includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic dimethanol, and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it includes structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may optionally include structural units derived from other dihydroxy compounds. Further details regarding polycarbonate resins suitably used for the second λ / 4 member and methods for forming the second λ / 4 member are described, for example, in Japanese Patent Publication Nos. 2014-10291, 2014-26266, 2015-212816, 2015-212817, and 2015-212818, and the descriptions in these publications are incorporated herein by reference.
[0031] The thickness of the second λ / 4 member, which is composed of a stretched resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, and more preferably 20 μm to 60 μm.
[0032] The orientation-solidified layer of the above-mentioned liquid crystal compound is a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer, and this orientation state is fixed. Note that the term "orientation-solidified layer" is a concept that includes the orientation-cured layer obtained by curing liquid crystal monomers, as described later. In the second λ / 4 member, typically, rod-shaped liquid crystal compounds are oriented in a state where they are aligned along the slow axis direction of the second λ / 4 member (homogenous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. Preferably, the liquid crystal compound is polymerizable. If the liquid crystal compound is polymerizable, the orientation state of the liquid crystal compound can be fixed by polymerizing it after orientation.
[0033] The above-mentioned oriented solidified layer of liquid crystal compound (liquid crystal oriented solidified layer) can be formed by applying an orientation treatment to the surface of a predetermined substrate, coating the surface with a coating liquid containing the liquid crystal compound to orient the liquid crystal compound in the direction corresponding to the orientation treatment, and fixing the orientation state. Any appropriate orientation treatment can be used as the orientation treatment. Specifically, these include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatment include magnetic field orientation treatment and electric field orientation treatment. Specific examples of chemical orientation treatment include oblique deposition and photo-orientation treatment. Any appropriate conditions can be adopted for each orientation treatment depending on the purpose.
[0034] The orientation of liquid crystal compounds is achieved by treating them at a temperature that exhibits the liquid crystal phase, depending on the type of liquid crystal compound. This temperature treatment causes the liquid crystal compound to enter a liquid crystal state, and it then orients according to the orientation treatment direction on the substrate surface.
[0035] In one embodiment, the orientation state is fixed by cooling the liquid crystal compound oriented as described above. If the liquid crystal compound is polymerizable or crosslinkable, the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment.
[0036] As the above-mentioned liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer may be used individually or in combination. Specific examples of liquid crystal compounds and methods for producing liquid crystal alignment solidified layers are described, for example, in Japanese Patent Publication No. 2006-163343, Japanese Patent Publication No. 2006-178389, and International Publication No. 2018 / 123551. The descriptions in these publications are incorporated herein by reference.
[0037] The thickness of the second λ / 4 member, which is composed of a liquid crystal alignment solidification layer, is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.
[0038] The phase difference Rth(550) in the thickness direction of the positive C plate described above is preferably -50nm to -300nm, more preferably -70nm to -250nm, even more preferably -90nm to -200nm, and particularly preferably -100nm to -180nm. Here, "nx=ny" includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the positive C plate is, for example, less than 10nm.
[0039] The positive C plate can be formed from any suitable material, but preferably it is composed of a film containing a liquid crystal material fixed in a homeotropic orientation. The liquid crystal material (liquid crystal compound) that can be homeotropically oriented may be a liquid crystal monomer or a liquid crystal polymer. Specific examples of methods for forming such liquid crystal compounds and positive C plates include the liquid crystal compound and the method for forming the phase difference layer described in paragraphs
[0020] to
[0028] of Japanese Patent Application Publication No. 2002-333642. In this case, the thickness of the positive C plate is preferably 0.5 μm to 5 μm.
[0040] The first protective member described above may typically be a laminated film having a base material and a surface treatment layer. The first protective member having a surface treatment layer may be arranged such that the surface treatment layer is located on the front side. Specifically, the surface treatment layer may be located on the outermost surface of the first laminated portion.
[0041] The first protective member has a maximum value of 0% to 1.2% in the 5° specular reflectance spectrum in the wavelength range of 420 nm to 680 nm, preferably 1.0% or less, and more preferably 0.8% or less. By positioning a protective member having such reflective properties on the outermost surface of the laminated portion, visibility can be dramatically improved. Specifically, by having a protective member in contact with the space formed between the first lens portion 16 and the second lens portion 24 satisfy the above reflective properties, light loss due to reflection at the interface between the air and the protective member can be suppressed very well. In the display system 2, which uses many components, the amount of light required is large, and the effect of suppressing light loss can be significantly obtained. As described above, in the display system 2 shown in Figure 1, light passes through the component placed 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 having the protective member satisfy the above reflective properties, the visibility of afterimages (ghosts) originating from reflection can be suppressed.
[0042] As mentioned above, when a large amount of light is used, hue control 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% to 0.4%, preferably 0.3%, more preferably 0.2%, and even more preferably 0.1%. The 5° specular reflectance of the first protective member at a wavelength of 600 nm is, for example, 0.01% to 0.4%, preferably 0.3%, more preferably 0.2%, and even more preferably 0.1%.
[0043] The 5° specular reflectance spectrum of the first protective member in the wavelength range of 420 nm to 680 nm may have minimum values 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, and more preferably 0.80 or less. Furthermore, 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, and more preferably 0.40 or less. The average value of the 5° specular reflectance can be obtained, for example, by extracting 7 measurement points at 5 nm intervals within each wavelength range and dividing the sum of these by the number of wavelengths extracted (7 points).
[0044] 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, the generation of diffused light can be suppressed, and blurring of the image can be suppressed. Substantially, 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.
[0045] Figure 3 is a schematic cross-sectional view showing the general structure 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. Surface smoothness can be measured by focusing the irradiated light onto the surface of the object.
[0046] The substrate 36 can be composed of any suitable film. Examples of materials that make up the film of the substrate 36 include cellulosic resins such as triacetylcellulose (TAC), polyester resins, polyvinyl alcohol resins, polycarbonate resins, polyamide resins, polyimide resins, polyethersulfone resins, polysulfone resins, polystyrene resins, cycloolefin resins such as polynorbornene, polyolefin resins, (meth)acrylic resins, acetate resins, etc. Here, (meth)acrylic refers to acrylic and / or methacrylic. In one embodiment, the substrate 36 is preferably composed of a (meth)acrylic resin. By using a (meth)acrylic resin, the above surface smoothness can be well satisfied. Specifically, by using a (meth)acrylic resin, a substrate with excellent surface smoothness can be manufactured by extrusion molding.
[0047] 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 includes, for example, a hard coat layer 38a and a functional layer 38b having an anti-reflective function.
[0048] 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 curing mechanisms for the curable compound include thermosetting and photocuring. Examples of curable compounds include monomers, oligomers, and prepolymers. Preferably, a polyfunctional monomer or oligomer is used as the curable compound. Examples of polyfunctional monomers or oligomers include monomers or oligomers having two or more (meth)acryloyl groups, urethane (meth)acrylate or urethane (meth)acrylate oligomers, epoxy monomers or oligomers, and silicone monomers or oligomers.
[0049] 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.
[0050] The functional layer 38b preferably 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 the high refractive index layer and the low refractive index layer in that order from the substrate 36 side. Having such a laminated structure allows for good satisfaction of the above-mentioned reflection characteristics.
[0051] For example, the high refractive index layer may be made of a high refractive index resin (for example, a refractive index of 1.55 or higher measured at a wavelength of 550 nm). In this case, the high refractive index layer may typically be a coating layer. Alternatively, the high refractive index layer may be made of an inorganic film. In this case, the high refractive index layer may typically be formed by physical vapor deposition such as vacuum deposition or sputtering, or by chemical vapor deposition.
[0052] The thickness of the high refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.
[0053] The thickness of the low refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.
[0054] The above-mentioned low refractive index layer (anti-reflective layer) can be obtained, for example, by coating a coating liquid for forming a low refractive index layer (anti-reflective layer), drying it, and curing the resulting coating film. The coating liquid for forming an anti-reflective layer may contain, for example, a resin component (curable compound), a fluorine-containing additive, hollow particles, solid particles, and a solvent, and can be obtained, for example, by mixing these.
[0055] Examples of curing mechanisms for the resin component (curable compound) contained in the anti-reflective coating liquid include thermosetting and photocuring types. Examples of resin components include curable compounds having at least one of an acrylate group and a methacrylate group, such as oligomers or prepolymers of polyfunctional compounds such as silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, and polyhydric alcohols, such as acrylates or methacrylates. These may be used individually or in combination of two or more types.
[0056] The above resin component may also be a reactive diluent having at least one of an acrylate group and a methacrylate group. The reactive diluent may be, for example, the reactive diluent described in Japanese Patent Application Publication No. 2008-88309, and includes, for example, monofunctional acrylate, monofunctional methacrylate, polyfunctional acrylate, polyfunctional methacrylate, etc. From the viewpoint of obtaining excellent hardness, a trifunctional or more acrylate or trifunctional or more methacrylate is preferably used as the reactive diluent. Examples of reactive diluents include butanediol glycerin ether diacrylate, isocyanuric acid acrylate, isocyanuric acid methacrylate, etc. These may be used individually or in combination of two or more. For curing the above resin component, a curing agent may be used, for example. As a curing agent, for example, a known polymerization initiator (e.g., a thermal polymerization initiator, a photopolymerization initiator, etc.) can be used.
[0057] The fluorine-containing additive mentioned above may be, for example, an organic compound containing fluorine, or an inorganic compound containing fluorine. Examples of organic compounds containing fluorine include fluorine-containing antifouling coatings, fluorine-containing acrylic compounds, and fluorine-silicon-containing acrylic compounds. Commercially available organic compounds containing fluorine can be used. Specific examples of commercially available products include "KY-1203" manufactured by Shin-Etsu Chemical Co., Ltd., and "Megafac" manufactured by DIC Corporation. The amount 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 per 100 parts by weight of the resin component, or it may be 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.
[0058] Examples of hollow particles used include silica particles, acrylic particles, and acrylic-styrene copolymer particles. Commercially available hollow silica particles (for example, "Thru-Ria 5320" and "Thru-Ria 4320" manufactured by JGC Catalysts & 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, and may also be 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 per 100 parts by weight of the above resin component, or it may be 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.
[0059] Examples of solid particles used include silica particles, zirconia particles, and titania particles. Commercially available solid silica particles (for example, Nissan Chemical Industries, Ltd.'s product 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 also 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 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 per 100 parts by weight of the resin component, or it may be 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.
[0060] Any suitable solvent can be used as the solvent mentioned above. Examples of solvents include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, TBA (tert-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 individually or in combination of two or more. The solvent content may be such that, for example, the weight of the solids relative to the total weight of the anti-reflective coating liquid is, for example, 0.1% by weight or more, 0.3% by weight or more, 0.5% by weight or more, 1.0% by weight or more, or 1.5% by weight or more, or 20% by weight or less, 15% by weight or less, 10% by weight or less, 5% by weight or less, or 3% by weight or less.
[0061] As a coating method for the anti-reflective layer forming coating liquid described above, known coating methods such as the fountain coating method, die coating method, spin coating method, spray coating method, gravure coating method, roll coating method, and bar coating method can be used. The drying temperature of the coating film is, for example, 30°C to 200°C, and the drying time is, for example, 30 seconds to 90 seconds. The coating film can be cured by, for example, heating or light irradiation (typically ultraviolet irradiation). As a light source for light irradiation, for example, a high-pressure mercury lamp can be used. The irradiation dose for ultraviolet irradiation is 50 mJ / cm² as the integrated exposure dose at an ultraviolet wavelength of 365 nm. 2 ~500mJ / cm 2 It is preferable that this be the case.
[0062] The second laminated portion 200 includes a reflective polarizing member 14 and an adhesive layer (e.g., an adhesive layer) disposed between the reflective polarizing member 14 and the second lens portion 24. The second laminated portion 200 further includes, for example, an absorptive polarizing member 28 disposed between the reflective polarizing member 14 and the second lens portion 24, from the viewpoint of improving visibility. The absorptive polarizing member 28 is laminated in front of the reflective polarizing member 14 via an adhesive layer (e.g., an adhesive layer) 44. The reflective axis of the reflective polarizing member 14 and the absorptive polarizing member 28 may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member 14 and the transmission axis of the absorptive polarizing member 28 may be arranged substantially parallel to each other. By laminating via an adhesive layer, the reflective polarizing member 14 and the absorptive polarizing member 28 are fixed, and misalignment of the axial arrangement between the reflective axis and the absorptive axis (transmission axis and transmission axis) can be prevented. In addition, adverse effects due to an air layer that may be formed between the reflective polarizing member 14 and the absorptive polarizing member 28 can be suppressed.
[0063] The second laminated portion 200 further includes a second protective member 32 positioned 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 tack layer) 43. The second protective member 32 may be located on the outermost surface of the second laminated portion 200. The first protective member 31 and the second protective member 32 are positioned opposite each other with space in between. The second protective member, like the first protective member, may typically be a laminated film having a base material and a surface treatment layer. In this case, the surface treatment layer may be located on the outermost surface of the second laminated portion. Details of the second protective member can be described in the same way as for the first protective member. Specifically, the reflective properties and their effects, smoothness, structure, thickness, and constituent materials of the second protective member can be described in the same way as for the first protective member.
[0064] In the example shown in Figure 2, the second laminated portion 200 further includes a third phase difference member 30 positioned between the absorptive polarizing member 28 and the second lens portion 24. The third phase difference member 30 is laminated to the absorptive polarizing member 28 via an adhesive layer (e.g., an adhesive layer) 45. The third phase difference member 30 is also laminated to the second lens portion 24 via an adhesive layer (e.g., an adhesive layer) 46, and the second laminated portion 200 is integrally provided with the second lens portion 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 lagging 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, reflection of ambient light from the second lens portion 16 side can be prevented. If the third phase difference member does not include any members other than the third λ / 4 member, the third phase difference member may correspond to the third λ / 4 member.
[0065] The above-described reflective polarizing member transmits polarized light parallel to its transmission axis (typically linearly polarized light) while maintaining its polarization state, and reflects light in other polarization states. Typically, the reflective polarizing member is composed of a multilayer film (sometimes referred to as a reflective polarizing film). In this case, the thickness of the reflective polarizing member is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.
[0066] Figure 4 is a schematic perspective view showing an example of a multilayer structure included in a reflective polarizing film. The multilayer structure 14a alternates between layers A, which have birefringence, and layers B, which have substantially no birefringence. The total number of layers constituting the multilayer structure may be 50 to 1000. For example, the refractive index nx in the x-axis direction of layer A is greater than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction and the refractive index ny in the y-axis direction of layer B are substantially the same, so the refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction can be the reflection axis and the y-axis direction can be the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3.
[0067] The above-mentioned layer A is typically composed of a material that exhibits birefringence upon stretching. Examples of such materials include naphthalenedicarboxylic acid polyester (e.g., polyethylene naphthalate), polycarbonate, and acrylic resins (e.g., polymethyl methacrylate). The above-mentioned layer B is typically composed of a material that does not substantially exhibit birefringence upon stretching. Examples of such materials include a copolyester of naphthalenedicarboxylic acid and terephthalic acid. The above multilayer structure can be formed by a combination of co-extrusion and stretching. For example, the materials constituting layer A and layer B are extruded and then multilayered (e.g., using a multiplier). The resulting multilayer laminate is then stretched. The x-axis direction in the illustrated example may correspond to the stretching direction.
[0068] Examples of commercially available reflective polarizing films include the product names "DBEF" and "APF" from 3M, and "APCF" from Nitto Denko.
[0069] The orthogonal transmittance (Tc) of the reflective polarizing member (reflective polarizing film) may be, for example, 0.01% to 3%. The single-element transmittance (Ts) of the reflective polarizing member (reflective polarizing film) may be, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing member (reflective polarizing film) may be, for example, 92% to 99.99%.
[0070] The above orthogonal transmittance, single-element transmittance, and polarization degree can be measured, for example, using a UV-Vis spectrophotometer. The polarization degree P can be calculated using a UV-Vis spectrophotometer to measure the single-element transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc, and then calculated from the obtained Tp and Tc using the following formula. Note that Ts, Tp, and Tc are Y values measured using a 2-degree field of view (C light source) according to JIS Z 8701 and corrected for luminous efficiency. Polarization degree P(%)={(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100
[0071] The above-mentioned absorption-type polarizing member may typically include a resin film containing a dichroic substance (sometimes referred to as an absorption-type polarizing film). The thickness of the absorption-type polarizing film is, for example, 1 μm or more and 20 μm or less, but may also be 2 μm or more and 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less.
[0072] The above-mentioned absorption polarizing film may be made from a single layer of resin film, or it may be made using a laminate of two or more layers.
[0073] When manufactured from a single layer of resin film, for example, an absorption polarizing film can be obtained by subjecting a hydrophilic polymer film, such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene-vinyl acetate copolymer film, to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment. Among these, an absorption polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.
[0074] The above iodine staining is carried out, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio for the above uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the staining treatment, or during the staining process. Alternatively, staining may be performed after stretching. If necessary, the PVA-based film may be subjected to swelling, crosslinking, washing, drying, etc.
[0075] When using the above-mentioned laminate of two or more layers, examples of laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate. An absorption polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated and formed on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of a resin substrate and a PVA-based resin layer; or by stretching and dyeing the laminate to make the PVA-based resin layer an absorption polarizing film. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halide and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, stretching may, if necessary, further include air-stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. In addition, in this embodiment, the laminate is preferably subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes applying an air-assisted stretching treatment, a dyeing treatment, a water-based stretching treatment, and a drying shrinkage treatment to the laminate in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated on a thermoplastic resin, making it possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA and dissolution when immersed in water in the subsequent dyeing and stretching processes, making it possible to achieve high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. As a result, the optical properties of the absorption polarizing film obtained through processing steps in which the laminate is immersed in a liquid, such as dyeing and water-based stretching, can be improved. Furthermore, by shrinking the laminate in the width direction through a drying shrinkage treatment, the optical properties can be improved.The resulting resin substrate / absorbent polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorbent polarizing film), or an appropriate protective layer may be laminated on the peeled surface obtained by removing the resin substrate from the resin substrate / absorbent polarizing film laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of such a method for manufacturing an absorbent polarizing film are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.
[0076] The orthogonal transmittance (Tc) of the absorbing polarizing member (absorbing polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single-layer transmittance (Ts) of the absorbing polarizing member (absorbing polarizing film) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorbing polarizing member (absorbing polarizing film) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.
[0077] The in-plane phase difference Re(550) of the third λ / 4 member described above is, for example, 100 nm to 190 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm. The third λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the third λ / 4 member is, for example, 0.75 or more and less than 1, and may also be 0.8 or more and 0.95 or less. The third λ / 4 member preferably exhibits a refractive index characteristic in which 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.
[0078] The third λ / 4 member is formed from any suitable material that can satisfy the above characteristics. The third λ / 4 member may be, for example, a stretched resin film or an oriented solidified layer of a liquid crystal compound. The same description as for the second λ / 4 member can be applied to the third λ / 4 member which is composed of a stretched resin film or an oriented solidified layer of a liquid crystal compound. The second λ / 4 member and the third λ / 4 member may be the same in composition (e.g., forming material, thickness, optical properties, etc.) or they may be different in composition. [Examples]
[0079] 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 values were measured using the methods described below. Unless otherwise specified, "parts" and "%" are based on weight. <thickness> Thicknesses of 10 μm or less were measured using a scanning electron microscope (JEOL Ltd., product name "JSM-7100F"). Thicknesses exceeding 10 μm were measured using a digital micrometer (Anritsu Corporation, product name "KC-351C"). <Surface smoothness> Surface smoothness was measured using a scanning white light interferometer (Zygo, product name "NewView9000"). Specifically, the sample was placed on a measurement platform with vibration isolation, interference fringes were generated using a single white LED illumination, and an interference objective lens (1.4x) with a reference plane was scanned in the Z direction (thickness direction) to selectively acquire the smoothness (surface smoothness) of the outermost surface of the measurement target within a 12.4 mm square field of view. A 5 μm thick acrylic adhesive layer with minimal irregularities was formed on a micro-slide glass (Matsunami Glass Industry Co., Ltd., product name "S200200"). The film to be measured was laminated to this adhesive surface, taking care to prevent foreign matter, air bubbles, or deformation streaks from entering, and the smoothness of the surface opposite the adhesive layer was measured. For the analysis, the surface smoothness (unit: arcmin) was defined as twice the angular index "Slope magnitude RMS" (equivalent to 2σ).
[0080] [Example 1] (Preparation of hard coat layer forming material) A hard coat layer forming material was prepared by mixing 50 parts of urethane acrylic oligomer (manufactured by Shin Nakamura Chemical Co., Ltd., "NK Oligo UA-53H"), 30 parts of polyfunctional acrylate mainly composed of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., product name "Viscote #300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1 part of leveling agent (manufactured by DIC Corporation, "GRANDIC PC4100"), and 3 parts of photopolymerization initiator (manufactured by Ciba Japan, "Irgacure 907"), and diluting with methyl isobutyl ketone to a solid content concentration of 50%.
[0081] (Preparation of coating solution for forming a high refractive index layer) 100 parts by weight of polyfunctional acrylate (manufactured by Arakawa Chemical Industries, Ltd., trade name "Opstar KZ6728", solids content 20% by weight), 3 parts by weight of leveling agent (manufactured by DIC, "GRANDIC PC4100"), and 3 parts by weight of photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solids content 100% by weight) were mixed. Butyl acetate was used as a diluent to adjust the solids content of the mixture to 12% by weight, and the mixture was stirred to prepare a coating solution for forming a high refractive index layer.
[0082] (Preparation of coating solution A for forming a low refractive index layer) A mixture was prepared by combining 100 parts by weight of a polyfunctional acrylate mainly composed of pentaerythritol triacrylate (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 & Chemicals Co., Ltd., product name "Thru-Ria 5320", solid content 20% by weight, weight-average particle size 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 size 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). To this mixture, a mixed solvent consisting of TBA (tert-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 diluent to adjust the total solid content to 4% by weight. The mixture was then stirred to prepare a coating solution for forming a low refractive index layer.
[0083] An acrylic film having a lactone ring structure (thickness 40 μm, surface smoothness 0.45 arcmin) is coated with the above-mentioned hard coat layer forming material and heated at 90°C for 1 minute. After heating, the coated layer is exposed to a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm². 2 An acrylic film (44 μm thick, with a surface smoothness of 0.4 arcmin on the hard coat side) was fabricated by curing the coated layer with ultraviolet light, forming a hard coat layer with a thickness of 4 μm. Next, the high refractive index layer-forming coating liquid was applied to the hard coat layer using a wire bar, and the applied coating liquid was heated at 80°C for 1 minute to dry and form a coating film. After drying, the coating film was exposed to a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm². 2 The coating was cured by irradiating it with ultraviolet light, forming a high refractive index layer with a thickness of 140 nm. Next, the low refractive index layer forming coating solution was applied to the high refractive index layer using a wire bar, and the applied coating solution was heated at 80°C for 1 minute to dry and form a coating film. After drying, the coating film was exposed to a high-pressure mercury lamp with an integrated light intensity of 300 mJ / cm². 2The coating was cured by irradiating it with ultraviolet light, forming a low refractive index layer with a thickness of 105 nm. In this way, a laminated film with a thickness of 44 μm and a surface smoothness of 0.4 arcmin was obtained.
[0084] [Comparative Example 1] A laminated film with 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 with a thickness of 100 nm was formed using coating solution B described below as the coating solution for forming the low refractive index layer.
[0085] (Preparation of coating solution B for forming a low refractive index layer) A mixture was prepared by combining 100 parts by weight of a polyfunctional acrylate mainly composed of pentaerythritol triacrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat #300", solid content 100% by weight), 100 parts by weight of hollow nanosilica particles (manufactured by JGC Catalysts & Chemicals Co., Ltd., trade name "Thru-Ria 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., trade name "KY-1203", solid content 20% by weight), and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight). To this mixture, a mixed solvent consisting of TBA (tert-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 diluent to prepare coating solution B for forming an anti-reflective low refractive index layer.
[0086] [Comparative Example 2] A laminated film with 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 and a low refractive index layer were not formed.
[0087] <Rating> (1) 5° specular reflectance Test specimens measuring 50 mm x 50 mm were cut from the laminated films of Example 1, Comparative Example 1, and Comparative Example 2, and these were attached to a black acrylic plate using adhesive to obtain measurement samples. A spectrophotometer (Hitachi High-Technologies Corporation, product name "U-4100") was used as the measuring device to measure the specular reflectance spectrum. The measurement wavelength was in the range of 420 nm to 680 nm, and the incident angle of light on the measurement sample was 5°.
[0088] Figure 5 shows the 5° specular reflectance spectra of the laminated films of Example 1 and Comparative Example 1. 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%. Furthermore, 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 for Comparative Example 1 and Comparative Example 2 are as follows.
[0089] [Table 1]
[0090] (2) Exterior 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 darkroom, the appearance (reflection) of the measurement plate was visually confirmed when light was shone from a surface-emitting unit (AItec, LED lighting box "LLBK1"), which was positioned 18 cm away from the measurement plate and facing it, using dimming volume 1. The reflections are shown in Figures 6(a), 6(b), and 6(c). Specifically, Figure 6(a) shows the results when irradiated with white light, Figure 6(b) shows the results when irradiated with blue light (wavelength 450 nm ± 30 nm), and Figure 6(c) shows the results when irradiated with red light (wavelength 630 nm ± 30 nm).
[0091] (3) Exterior 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 (AItec, LED lighting box "LLBK1") was set up in a dark room, and the measurement plate was placed on its light-emitting surface. The appearance of the measurement plate (transmitted appearance) was visually confirmed when light was irradiated from the surface-emitting unit using dimming volume 1. The transmitted appearance is shown in Figures 7(a), 7(b), 7(c), and 7(d). Figure 7(a) shows the result when irradiated with white light, Figure 7(b) shows the result when irradiated with blue light (wavelength 450nm ± 30nm), Figure 7(c) shows the result when irradiated with red light (wavelength 630nm ± 30nm), and Figure 7(d) shows the result when irradiated with green light (wavelength 530nm ± 30nm).
[0092] As shown in Figures 6(a), 6(b), and 6(c), Example 1 exhibits significantly superior reflective appearance compared to Comparative Examples 1 and 2. While the above evaluation used a black acrylic plate assuming a combination with an absorbing polarizing member, a similar difference in reflective appearance was observed even when using a transparent glass plate. According to Example 1, it is considered that the embodiment of the present invention can very effectively resolve the ghosting problem that can occur in a display system due to reflected light. Furthermore, as shown in Figures 7(a), 7(b), 7(c), and 7(d), the transmitted appearance of Example 1, Comparative Example 1, and Comparative Example 2 is not significantly different.
[0093] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the configurations shown in the embodiments above can be replaced with configurations that are substantially the same, configurations that produce the same effects, or configurations that can achieve the same purpose. [Industrial applicability]
[0094] The lens portion according to an embodiment of the present invention can be used, for example, in a display device such as VR goggles. [Explanation of symbols]
[0095] 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 Absorbing 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 laminated section, 200 Second laminated section.
Claims
1. A lens component used in a display system that displays images to a user, A reflective polarizing member that reflects light emitted forward from the display surface of an image display element and that has passed through the polarizing member and the first λ / 4 member, A first lens portion is arranged in the optical path between the display element and the reflective polarizing member, A half-mirror is disposed between the display element and the first lens portion, which transmits light emitted from the display element and reflects the light reflected by the reflective polarizing member toward the reflective polarizing member, A second lens portion is positioned in front of the reflective polarizing member, A second λ / 4 member is positioned in the optical path between the half mirror and the reflective polarizing member, A first protective member and a second protective member are arranged in the optical path between the half mirror and the reflective polarizing member, Equipped with, The first protective member and the second protective member are arranged facing each other with space in between. The first protective member and the second protective member each have a maximum value of 1.2% or less of the 5° specular reflectance spectrum in the wavelength range of 420 nm to 680 nm. The lens portion comprises a first laminated portion including the second λ / 4 member and the first protective member, and a second laminated portion including the reflective polarizing member and the second protective member, The 5° specular reflectance spectra of the first protective member and the second protective member in the wavelength range of 420 nm to 680 nm have minimum values in the wavelength range of 450 nm to 480 nm and in the wavelength range of 600 nm to 630 nm. The ratio of the average value Ave(530-560nm) of the 5° specular reflectance of the first protective member in the wavelength range of 450 nm to 480 nm to the average value Ave(450-480 nm) of the 5° specular reflectance of the first protective member in the wavelength range of 530 nm to 560 nm is 0.10 or more and 0.90 or less. The ratio of the average value Ave(530-560nm) of the 5° specular reflectance of the second protective member in the wavelength range of 450 nm to 480 nm to the average value Ave(450-480 nm) of the 5° specular reflectance of the second protective member in the wavelength range of 530 nm to 560 nm is 0.10 or more and 0.90 or less. The ratio of the average value Ave(530-560nm) of the 5° specular reflectance of the first protective member in the wavelength range of 600 nm to 630 nm to the average value Ave(600-630 nm) of the 5° specular reflectance of the first protective member in the wavelength range of 530 nm to 560 nm is 0.10 or more and 0.50 or less. The ratio of the average value Ave(530-560nm) of the 5° specular reflectance of the second protective member in the wavelength range of 600 nm to 630 nm to the average value Ave(530-630nm) of the 5° specular reflectance of the second protective member in the wavelength range of 530 nm to 560 nm is 0.10 or more and 0.50 or less. Lens section.
2. 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.
3. 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.
4. 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.
5. The lens portion according to claim 1, wherein the second λ / 4 member satisfies Re(450) < Re(550).
6. The lens portion according to claim 1, wherein the second laminated portion includes an absorbing polarizing member disposed between the reflective polarizing member and the second lens portion.
7. The lens portion according to claim 1, wherein the second laminated portion includes a third λ / 4 member disposed between the reflective polarizing member and the second lens portion.
8. The lens portion according to claim 7, wherein the third λ / 4 member satisfies Re(450) < Re(550).
9. The steps include passing the light representing the image, emitted through the polarizing member and the first λ / 4 member, through the half mirror and the first lens portion, The steps include: passing the light that has passed through the half mirror and the first lens portion through the second λ / 4 member; The steps include: reflecting the light that has passed through the second λ / 4 member toward the half mirror using a reflective polarizing member; The steps include: making the light reflected by the reflective polarizing member and the half mirror passable through the reflective polarizing member by the second λ / 4 member; The steps include: passing the light transmitted through the reflective polarizing member through the second lens portion; A method of display having, A laminated film arranged on the optical path between the half mirror and the reflective polarizing member, and in contact with the space formed between the first lens portion and the second lens portion, The maximum value of the 5° specular reflectance spectrum in the wavelength range of 420 nm to 680 nm is 1.2% or less. The 5° specular reflectance spectrum in the wavelength range of 420 nm to 680 nm has minimum values in the wavelength range of 450 nm to 480 nm and in the wavelength range of 600 nm to 630 nm. The ratio of the average value Ave(450-480nm) of the 5° specular reflectance in the wavelength range of 450nm to 480nm to the average value Ave(530-560nm) of the 5° specular reflectance in the wavelength range of 530nm to 560nm is between 0.10 and 0.
90. The ratio of the average value Ave(530-560nm) of the 5° specular reflectance in the wavelength range of 600 nm to 630 nm to the average value Ave(600-630 nm) of the 5° specular reflectance in the wavelength range of 530 nm to 560 nm is between 0.10 and 0.
50. Laminated film.