Optical stack and display system

Abstract

Provided is an optical laminate including a phase difference member and a protective member, the phase difference member having a first main surface and a second main surface facing each other, and converting linearly polarized light incident from the first main surface side into circularly polarized light and emitting the light from the second main surface side, the protective member having a slow axis and disposed on the second main surface side of the phase difference member, the angle between the slow axis of the protective member and the polarization direction of the linearly polarized light being 15° or less or 75° to 105°.

Description

Technical Field

[0001] This invention relates to optical laminates and display systems. Background Technology

[0002] Image display devices, such as liquid crystal displays and electroluminescent (EL) displays (e.g., organic EL displays), are rapidly gaining popularity. In image display devices, optical components such as phase retardation components and polarization components are typically used to achieve image display and improve image display performance (e.g., see Patent Document 1). These optical components can be pre-integrated and mounted on the image display device as an optical laminate.

[0003] In recent years, new applications for image display devices have been developed. For example, goggles with displays (VR goggles) for realizing Virtual Reality (VR) have begun to be commercialized. Research is underway into the use of VR goggles in various scenarios, with hopes for improvements such as lighter weight and enhanced visual recognition.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2021-103286 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The aforementioned reduction in the weight of VR goggles can be achieved, for example, by thinning the lenses used in VR goggles. On the other hand, it is also desirable to develop optical laminates that include the aforementioned optical components suitable for display systems using lenses.

[0009] In view of the above, the main objective of the present invention is to provide an optical laminate that can improve visual recognition and effectively achieve lightweight VR goggles.

[0010] Problem Solving Methods

[0011] [1] According to one aspect of the present invention, an optical laminate may be provided, comprising:

[0012] A phase difference member having a first principal surface and a second principal surface opposite to each other, and converting linearly polarized light incident from the first principal surface side into circularly polarized light and exiting from the second principal surface side; and

[0013] A protective member having a slow axis and disposed on the second principal surface side of the aforementioned phase difference member.

[0014] The angle between the slow axis of the aforementioned protective component and the polarization direction of the aforementioned linearly polarized light is less than 15° or between 75° and 105°.

[0015] [2] In the optical stack described in [1] above, the phase difference member may include a λ / 4 layer with Re(550) of 100nm~190nm, and the angle between the slow axis of the protective member and the slow axis of the λ / 4 layer may be 30°~60°.

[0016] [3] In the optical laminate described in [1] or [2] above, a polarizing member disposed on the first main surface side of the phase difference member may be further included, and the angle between the slow axis of the protective member and the polarization axis of the polarizing member may be less than 15° or 75° to 105°.

[0017] [4] In any one of the optical laminates described in [1] to [3] above, the difference between the ellipticity of the circularly polarized light with a wavelength of 550 nm emitted from the second main surface side of the phase difference member and the ellipticity of the circularly polarized light with a wavelength of 550 nm emitted through the protective member can be 0.02 or less.

[0018] [5] The optical laminate described in any one of [1] to [4] above can satisfy at least one of the following (i) and (ii):

[0019] (i) The difference between the ellipticity of the circularly polarized light with a wavelength of 450 nm emitted from the second principal surface side of the phase difference member and the ellipticity of the circularly polarized light with a wavelength of 450 nm emitted after the circularly polarized light passes through the protective member is 0.02 or less.

[0020] (ii) The difference between the ellipticity of the 650nm wavelength light emitted from the second principal surface side of the phase difference member and the ellipticity of the 650nm wavelength light emitted from the circularly polarized light after the circularly polarized light passes through the protective member is 0.02 or less.

[0021] [6] In any one of the optical laminates described in [1] to [5] above, the protective member may include a substrate, which may include at least one resin selected from acrylic resins and cellulose triacetate resins.

[0022] [7] In the optical laminate described in [6] above, the protective member may further include an anti-reflective layer disposed on the opposite side of the substrate on the side where the phase difference member is disposed.

[0023] [8] In any of the optical laminates described in [1] to [7] above, the Re(550) of the above protective member can be 0.5 nm or more.

[0024] [9] In any of the optical laminates described in [1] to [8] above, the phase difference member and the protective member are laminated together via an adhesive layer.

[0025]

[10] The optical laminate described in any one of [1] to [9] above can be used in a display system, wherein the display system comprises:

[0026] A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member;

[0027] A reflective polarizing member is disposed in front of the display element and reflects light emitted from the display element;

[0028] A first lens portion is disposed in the optical path between the display element and the reflective polarizing member;

[0029] A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member;

[0030] A first phase difference member, disposed in the optical path between the display element and the semi-reflective mirror, is capable of converting linearly polarized light into circularly polarized light, or vice versa; and

[0031] The second phase difference component is disposed in the optical path between the semi-reflective mirror and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa.

[0032] The aforementioned phase difference component can be configured to function as either the aforementioned first phase difference component or the aforementioned second phase difference component.

[0033]

[11] According to another aspect of the present invention, a display system comprising:

[0034] A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member;

[0035] A reflective polarizing member is disposed in front of the display element and reflects light emitted from the display element;

[0036] A first lens portion is disposed in the optical path between the display element and the reflective polarizing member;

[0037] A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member;

[0038] A first phase difference member, disposed in the optical path between the display element and the semi-reflective mirror, is capable of converting linearly polarized light into circularly polarized light, or vice versa; and

[0039] The second phase difference component is disposed in the optical path between the semi-reflective mirror and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa.

[0040] An optical laminate as described in any one of [1] to

[10] is disposed behind the aforementioned semi-reflective mirror, such that the second principal surface of the aforementioned phase difference member becomes the side of the aforementioned semi-reflective mirror.

[0041]

[12] According to another aspect of the present invention, a display system comprising:

[0042] A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member;

[0043] A reflective polarizing member is disposed in front of the display element and reflects light emitted from the display element;

[0044] A first lens portion is disposed in the optical path between the display element and the reflective polarizing member;

[0045] A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member;

[0046] A first phase difference member, disposed in the optical path between the display element and the semi-reflective mirror, is capable of converting linearly polarized light into circularly polarized light, or vice versa; and

[0047] The second phase difference component is disposed in the optical path between the semi-reflective mirror and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa.

[0048] An optical laminate as described in any one of [1] to

[10] is disposed in front of the semi-reflective mirror, such that the second principal surface of the phase difference member becomes the side of the semi-reflective mirror.

[0049] The effects of the invention

[0050] The optical laminate according to embodiments of the present invention can improve visual recognition and effectively achieve lightweight VR goggles. Attached Figure Description

[0051] Figure 1 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to one embodiment of the present invention.

[0052] Figure 2 Through Figure 1 A schematic diagram illustrating the polarization state of light in the optical laminate shown.

[0053] Figure 3 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to one embodiment of the present invention.

[0054] Figure 4 Through Figure 3 A schematic diagram illustrating the polarization state of light in the optical laminate shown.

[0055] Figure 5 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to one embodiment of the present invention.

[0056] Figure 6 It is by Figure 5 A schematic diagram illustrating the polarization state of light reflected and emitted from the optical laminate.

[0057] Figure 7 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to one embodiment of the present invention.

[0058] Figure 8 This is a schematic diagram illustrating a simplified configuration of a display system according to one embodiment of the present invention.

[0059] Figure 9 It is shown Figure 8 A schematic side view of an example of the specific configuration of a portion of the display system shown.

[0060] Figure 10 It is shown Figure 8 A schematic side view of an example of the specific configuration of a portion of the display system shown.

[0061] Figure 11 It is shown Figure 8 A schematic side view of an example of the specific configuration of a portion of the display system shown.

[0062] Figure 12This is a graph showing the difference between the ellipticity of transmitted light measured with respect to the optical laminates made in the embodiments and comparative examples and the ellipticity of transmitted light measured with respect to the optical laminate of Reference Example 1.

[0063] Figure 13 This is a graph showing the difference between the ellipticity of transmitted light measured with respect to the optical laminates made in the embodiments and comparative examples and the ellipticity of transmitted light measured with respect to the optical laminate of Reference Example 1.

[0064] Figure 14 This is a graph showing the difference between the ellipticity of transmitted light measured with respect to the optical laminates fabricated in the Examples and Comparative Examples and the ellipticity of transmitted light measured with respect to the optical laminate of Reference Example 2.

[0065] Figure 15 This is a graph showing the difference between the ellipticity of transmitted light measured with respect to the optical laminates fabricated in the Examples and Comparative Examples and the ellipticity of transmitted light measured with respect to the optical laminate of Reference Example 2.

[0066] Symbol Explanation

[0067] 2 Display System

[0068] 4. Lens section

[0069] 10 Absorption-type polarizing components

[0070] 12 display elements

[0071] 12a display surface

[0072] 14. Reflective polarizing element

[0073] 15 Absorption-type polarizing components

[0074] 16 First Lens Section

[0075] 18 Semi-reflective mirrors

[0076] 20 Phase difference components

[0077] 21a λ / 4 layers

[0078] 21b λ / 2 layers

[0079] 21c λ / 4 layers

[0080] 22 First phase difference component

[0081] 23 Second phase difference component

[0082] 24 Second Lens Section

[0083] 30 Protective components

[0084] 40 Adhesive layer

[0085] 100 optical laminates Detailed Implementation

[0086] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings, but the present invention is not limited to these embodiments. For clarity, the drawings sometimes schematically show the width, thickness, shape, etc., of various parts compared to the embodiments, but these are merely examples and do not limit the interpretation of the present invention. Furthermore, regarding the drawings, sometimes the same or equivalent elements are labeled with the same symbols, and repeated descriptions are omitted.

[0087] (Definitions of terms and symbols)

[0088] The terms and symbols used in this manual are defined as follows.

[0089] (1) Refractive index (nx, ny, nz)

[0090] “nx” is the refractive index in the direction where the refractive index reaches its maximum in the plane (i.e., the slow axis direction), “ny” is the refractive index in the direction orthogonal to the slow axis in the plane (i.e., the fast axis direction), and “nz” is the refractive index in the thickness direction.

[0091] (2) In-plane phase difference (Re)

[0092] “Re(λ)” is the in-plane phase difference measured at 23°C with light of wavelength λnm. For example, “Re(550)” is the in-plane phase difference measured at 23°C with light of wavelength 550nm. When the thickness of the layer (film) is set as d (nm), Re(λ) can be obtained by the formula: Re(λ)=(nx-ny)×d.

[0093] (3) Phase difference (Rth) in the thickness direction

[0094] “Rth(λ)” is the phase difference in the thickness direction measured at 23°C using light with a wavelength of λnm. For example, “Rth(550)” is the phase difference in the thickness direction measured at 23°C using light with a wavelength of 550nm. When the thickness of the layer (film) is set as d (nm), Rth(λ) can be obtained using the formula: Rth(λ)=(nx-nz)×d.

[0095] (4) Nz coefficient

[0096] The coefficient of Nz can be obtained by Nz = Rth / Re.

[0097] (5) Angle

[0098] In this specification, when referring to angles, unless otherwise specified, the angle includes both clockwise and counterclockwise directions relative to a reference direction. Therefore, for example, "45°" means ±45°. Furthermore, in this specification, "substantially parallel" includes a range of 0°±10°, preferably 0°±5°, more preferably 0°±3°, and even more preferably 0°±1°. "Substantially orthogonal" includes a range of 90°±10°, preferably 90°±5°, more preferably 90°±3°, and even more preferably 90°±1°.

[0099] A. Optical laminate

[0100] Figure 1 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to one embodiment of the present invention. Figure 2 Through Figure 1 The schematic diagram illustrating the polarization state of light in the optical laminate shown omits some components. The optical laminate 100A includes: a phase difference member 20 having a first principal surface 20a and a second principal surface 20b facing each other, which converts linearly polarized light LP1 incident from the first principal surface 20a side into circularly polarized light CP1 and exits from the second principal surface 20b side; and a protective member 30 disposed on the second principal surface 20b side of the phase difference member 20. The protective member 30 has a slow axis a, and is configured such that the angle between the slow axis a and the polarization direction b of the linearly polarized light LP1 incident on the first principal surface 20a of the phase difference member 20 is, for example, 15° or less, preferably 10° or less, more preferably 5° or less, and even more preferably 3° or less. Alternatively, unlike the example in the figure, the protective member 30 may also be configured such that the angle between the slow axis a and the polarization direction b of the linearly polarized light LP1 is, for example, 75°~105°, preferably 80°~100°, more preferably 85°~95°, and even more preferably 87°~93°.

[0101] According to the optical laminate having the configuration described above, the effect of the in-plane phase difference of the protective member 30 can be suppressed, and the ellipticity of the light (circularly polarized light) CP2 after passing through the protective member 30 can be prevented from changing significantly compared with the ellipticity of the light (circularly polarized light) CP1 after passing through the phase difference member 20.

[0102] It should be noted that in this specification, the term "circularly polarized light" refers not only to fully circularly polarized light with an ellipticity of 1, but may also include elliptically polarized light with an ellipticity of less than 1.

[0103] The optical laminate 100A further includes an adhesive layer 40 on the first main surface 20a side of the phase retardation member 20. The adhesive layer 40 can be used to bond the optical laminate 100A to a desired member. During the period before the optical laminate 100A is available for use, a release liner (not shown) can be temporarily bonded to the surface of the adhesive layer 40, and a surface protective film (not shown) can be temporarily bonded to the surface of the protective member 30.

[0104] Typically, the phase difference member 20 and the protective member 30 are laminated together via an adhesive layer 50a.

[0105] Figure 3 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to another embodiment of the present invention. Figure 4 Through Figure 3 The schematic diagram illustrating the polarization state of light in the optical laminate shown omits some components. The optical laminate 100B differs from optical laminate 100A in that it further includes an adhesive layer 50b and an absorptive polarizing member 10 arranged sequentially from the phase difference member 20 side between the phase difference member 20 and the adhesive layer 40. In optical laminate 100B, the angle between the polarization transmission axis c of the absorptive polarizing member 10 and the slow axis a of the protective member 30 is, for example, 15° or less, preferably 10° or less, more preferably 5° or less, and even more preferably 3° or less. Alternatively, unlike the example shown, the angle between the polarization transmission axis c of the absorptive polarizing member 10 and the slow axis a of the protective member 30 is, for example, 75° to 105°, preferably 80° to 100°, more preferably 85° to 95°, and even more preferably 87° to 93°.

[0106] According to the optical laminate having the configuration described above, light incident on the side of the absorptive polarizing member 10 will pass through the absorptive polarizing member 10 and be emitted as linearly polarized light LP1. After being converted into circularly polarized light CP1 by the phase difference member 20, it will pass through the protective member 30 and be emitted as circularly polarized light CP2 without significantly changing its ellipticity.

[0107] Figure 5 This is a schematic cross-sectional view illustrating a simplified configuration of an optical laminate according to another embodiment of the present invention. Figure 6 It is by Figure 5The schematic diagram illustrating the polarization state of light reflected and emitted by the optical laminate is shown, but some components are omitted. The optical laminate 100C differs from optical laminate 100A in that it further includes, between the phase difference member 20 and the adhesive layer 40, an adhesive layer 50c, a reflective polarizing member 14, an adhesive layer 50d, and an absorptive polarizing member 15 arranged sequentially from the phase difference member 20 side. In optical laminate 100C, the angle between the polarization reflection axis d of the reflective polarizing member 14 and the slow axis a of the protective member 30 is, for example, set to 15° or less, preferably 10° or less, more preferably 5° or less, and even more preferably 3° or less. Alternatively, unlike the example shown, the angle between the polarization reflection axis d of the reflective polarizing member 14 and the slow axis a of the protective member 30 is, for example, 75° to 105°, preferably 80° to 100°, more preferably 85° to 95°, and even more preferably 87° to 93°. Typically, the polarization reflection axis d of the reflective polarization member 14 is substantially parallel to the polarization absorption axis e of the absorptive polarization member 15, and the polarization transmission axis of the reflective polarization member 14 is substantially parallel to the polarization transmission axis of the absorptive polarization member 15. Depending on the purpose, the absorptive polarization member 15 may not be provided.

[0108] According to the optical laminate having the configuration described above, the linearly polarized light LP1 reflected by the reflective polarizing member 14 toward the phase difference member 20 is converted into circularly polarized light CP1 by the phase difference member 20, and is emitted as circularly polarized light CP2 through the protective member 30 without significantly changing its ellipticity.

[0109] In this specification, the polarization transmission axis, polarization absorption axis, and polarization reflection axis are sometimes referred to as the transmission axis, absorption axis, and reflection axis, respectively. Alternatively, they are sometimes collectively referred to as the polarization axis.

[0110] In the optical laminate of the embodiment of the present invention, when linearly polarized light is incident on the phase difference member from the first principal surface side and circularly polarized light is emitted from the second principal surface side, the difference between the ellipticity of the circularly polarized light with a wavelength of 550 nm emitted from the second principal surface side and the ellipticity of the circularly polarized light with a wavelength of 550 nm emitted through the protective member (in the example shown, |ellipticity of circularly polarized light CP1 with a wavelength of 550 nm - ellipticity of circularly polarized light CP2 with a wavelength of 550 nm|) is, for example, 0.02 or less, preferably 0 to 0.015, more preferably 0 to 0.01, and even more preferably 0 to 0.005.

[0111] In one embodiment, when linearly polarized light is incident on the phase difference member of the optical laminate from the first main surface side and circularly polarized light is emitted from the second main surface side, the difference between the ellipticity of the 450nm circularly polarized light emitted from the second main surface side and the ellipticity of the 450nm circularly polarized light emitted through the protective member (in the example shown, |ellipticity of 450nm circularly polarized light CP1 - ellipticity of 450nm circularly polarized light CP2|) is, for example, 0.02 or less, preferably 0 to 0.015, more preferably 0 to 0.01, and even more preferably 0 to 0.005.

[0112] In one embodiment, when linearly polarized light is incident on the phase difference member of the optical laminate from the first main surface side and circularly polarized light is emitted from the second main surface side, the difference between the ellipticity of the 650nm circularly polarized light emitted from the second main surface side and the ellipticity of the 650nm circularly polarized light emitted through the protective member (in the example shown, |ellipticity of 650nm circularly polarized light CP1 - ellipticity of 650nm circularly polarized light CP2|) is, for example, 0.02 or less, preferably 0 to 0.015, more preferably 0 to 0.01, and even more preferably 0 to 0.005.

[0113] The aforementioned optical laminate can be in the form of a strip or a single sheet. The top view of a single-sheet optical laminate can be, for example, a rectangular shape, a rounded rectangle, etc. In this specification, "strip-shaped" refers to an elongated shape whose length is sufficiently long relative to its width, for example, including elongated shapes whose length is 10 times or more, preferably 20 times or more, than its width. The strip-shaped optical laminate can be wound into a roll.

[0114] [Phase difference component]

[0115] The phase grading member 20 has a first principal surface 20a and a second principal surface 20b that are opposite to each other, and is capable of converting linearly polarized light incident from the first principal surface 20a side into circularly polarized light and exiting from the second principal surface 20b side. The ellipticity of the circularly polarized light with a wavelength of 550 nm exiting from the second principal surface side of the phase grading member can, for example, be 0.90 or higher, 0.92 or higher, or 0.94 or higher. The ellipticity of the circularly polarized light with a wavelength of 450 nm exiting from the second principal surface side of the phase grading member can, for example, be 0.80 or higher, 0.83 or higher, or 0.85 or higher. The ellipticity of the circularly polarized light with a wavelength of 650 nm exiting from the second principal surface side of the phase grading member can, for example, be 0.78 or higher, 0.80 or higher, or 0.83 or higher.

[0116] The surface smoothness of the phase difference member 20 is, for example, 1.00 arcmin or less, preferably 0.8 arcmin or less, more preferably 0.6 arcmin or less, and even more preferably 0.4 arcmin or less. If it is within such a range, a display system with excellent visual recognition can be achieved. For example, by satisfying such surface smoothness, the uniformity of the in-plane phase difference can be improved, and as a result, a display system with excellent display characteristics can be obtained.

[0117] The thickness deviation of the phase difference member 20 is preferably 1 μm or less, more preferably 0.8 μm or less, even more preferably 0.6 μm or less, and even more preferably 0.4 μm or less. With such a thickness deviation, for example, the aforementioned surface smoothness can be well achieved. Here, the thickness deviation can be determined by measuring the thickness of the first portion located within the measurement surface and the thickness at positions spaced apart by a given interval (e.g., 5 mm to 15 mm) in any direction (e.g., upward, downward, leftward, and rightward) from the first portion.

[0118] The phase difference component 20 includes one or more phase difference layers.

[0119] In one embodiment, the phase difference member 20 is configured to convert linearly polarized light into circularly polarized light via a λ / 4 layer. Specifically, the phase difference member 20 includes a λ / 4 layer arranged such that its slow axis forms an angle of, for example, 40°~50°, 42°~48°, or approximately 45° with the polarization direction of the linearly polarized light incident from the first principal surface 20a side. The phase difference member 20 configured as described above can also convert circularly polarized light incident from one principal surface side into linearly polarized light and exit from the other principal surface side. In this embodiment, as... Figure 3 As shown in the optical laminate 100B, in a configuration where an absorption-type polarizing member 10 is disposed on the side opposite to the side where the protective member 30 is disposed on the phase difference member 20, the polarization direction of the linearly polarized light is substantially the same as the transmission axis c of the absorption-type polarizing member 10. Therefore, in the above configuration, the angle between the slow axis of the λ / 4 layer 21a and the transmission axis c of the absorption-type polarizing member 10 can be, for example, 40°~50°, 42°~48°, or about 45°, and the angle between the slow axis of the λ / 4 layer 21a and the absorption axis of the absorption-type polarizing member 10 can be, for example, 40°~50°, 42°~48°, or about 45°.

[0120] The in-plane phase difference Re(550) of the λ / 4 layer 21a is, for example, 100nm~190nm, 110nm~180nm, 130nm~160nm, or 135nm~155nm.

[0121] The λ / 4 layer 21a preferably exhibits inverse dispersion wavelength characteristics, where the phase difference value increases accordingly with the wavelength of the measurement light. The Re(450) / Re(550) of the λ / 4 layer 21a is, for example, less than 1, and can be less than 0.95, further less than 0.90, and further less than 0.85. The Re(450) / Re(550) of the λ / 4 layer 21a is, for example, greater than 0.75.

[0122] The λ / 4 layer 21a preferably exhibits a refractive index characteristic of nx > ny ≥ nz. Here, "ny = nz" not only means that ny and nz are exactly equal, but also includes the case where they are substantially equal. Therefore, it is permissible to have ny < nz without impairing the effect of the present invention. The Nz coefficient of the λ / 4 layer 21a 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.

[0123] The surface smoothness of the λ / 4 layer 21a is, for example, 1.00 arcmin or less, preferably 0.8 arcmin or less, more preferably 0.6 arcmin or less, and even more preferably 0.4 arcmin or less.

[0124] The λ / 4 layer 21a is formed of any suitable material capable of satisfying the above characteristics. For example, the λ / 4 layer 21a can be a stretched film of a resin film or an orientation-cured layer of a liquid crystal compound.

[0125] Examples of resins included in the aforementioned resin films 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 can be used alone or in combination (e.g., blending, copolymerization). When the λ / 4 layer 21a exhibits inverse dispersion wavelength characteristics, a resin film containing polycarbonate resins or polyester carbonate resins (hereinafter, sometimes simply referred to as polycarbonate resins) can be suitably used.

[0126] As the aforementioned polycarbonate resin, any suitable polycarbonate resin can be used as long as the effects of the present invention are achieved. For example, the polycarbonate resin comprises structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from alicyclic diols, alicyclic diethanols, di-, tri-, or polyethylene glycols, and alkylene diols or spirodiols. Preferably, the polycarbonate resin comprises structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from alicyclic diethanols and / or structural units derived from di-, tri-, or polyethylene glycols; more preferably, it comprises structural units derived from fluorene dihydroxy compounds, structural units derived from isosorbide dihydroxy compounds, and structural units derived from di-, tri-, or polyethylene glycols. The polycarbonate resin may also, as needed, comprise structural units derived from other dihydroxy compounds. It should be noted that details of the polycarbonate resin suitable for use in λ / 4 layer 21a and the method for forming λ / 4 layer 21a are described, for example, in Japanese Patent Application Publication Nos. 2014-10291, 2014-26266, 2015-212816, 2015-212817, and 2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0127] The orientation-cured layer of the aforementioned liquid crystal compound is a layer in which the liquid crystal compound is oriented in a given direction within the layer, and its orientation state is fixed. It should be noted that "orientation-cured layer" includes the concept of an orientation-cured layer obtained by curing liquid crystal monomers as described below. Typically, rod-shaped liquid crystal compounds are oriented in a state of alignment along the slow axis direction of the λ / 4 layer 21a (homogeneous alignment). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. The liquid crystal compound is preferably capable of polymerization. If the liquid crystal compound is capable of polymerization, the orientation state of the liquid crystal compound can be fixed by performing polymerization after orienting the liquid crystal compound.

[0128] The alignment-cured layer (liquid crystal alignment-cured layer) of the aforementioned liquid crystal compound can be formed by the following method: an alignment treatment is performed on the surface of a given substrate; a coating liquid containing the liquid crystal compound is applied to the surface; the liquid crystal compound is aligned along a direction corresponding to the alignment treatment; and the alignment state is fixed. Any suitable alignment treatment can be used. Examples include mechanical alignment treatment, physical alignment treatment, and chemical alignment treatment. Specific examples of mechanical alignment treatment include friction 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 tilting vapor deposition and photo-alignment treatment. The processing conditions for each alignment treatment can be any suitable condition depending on the purpose.

[0129] The orientation of a liquid crystal compound can be achieved by processing it at a temperature that reveals a liquid crystal phase, corresponding to the type of liquid crystal compound. Through such temperature processing, the liquid crystal compound is in a liquid crystal state, and is oriented in accordance with the orientation processing direction of the substrate surface.

[0130] In one embodiment, the orientation state is fixed by cooling the oriented liquid crystal compound as described above. If the liquid crystal compound is polymerizable or crosslinkable, the orientation state can be fixed by performing a polymerization or crosslinking treatment on the oriented liquid crystal compound as described above.

[0131] As the aforementioned liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer can be used alone or in combination. Specific examples of liquid crystal compounds and methods for fabricating liquid crystal alignment fixing layers are described, for example, in Japanese Patent Application Publication No. 2006-163343, Japanese Patent Application Publication No. 2006-178389, and International Publication No. 2018 / 123551. The contents of these publications are incorporated herein by reference.

[0132] When the λ / 4 layer 21a is a stretched film of resin film, its thickness is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 60 μm, and even more preferably 20 μm to 50 μm. When the λ / 4 layer 21a is an orientation-cured layer of liquid crystal compound, its thickness 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.

[0133] In another embodiment, the phase difference member 20 is configured to convert linearly polarized light into circularly polarized light via λ / 2 and λ / 4 layers. Specifically, the phase difference member 20 includes λ / 2 and λ / 4 layers arranged sequentially toward the protective member 30 side (in other words, toward the second main surface 20b side). Regarding this embodiment, if referring to... Figure 7 The optical laminate 100D shown will be described from the first main surface side of the phase difference member 20 ( Figure 7 The polarization direction of linearly polarized light incident on the side of the absorption polarizing member 10 (in the middle) Figure 7 The angle between the transmission axis direction of the absorption polarizing member 10 and the slow axis direction of the λ / 2 layer 21b can be, for example, 55°~85°, 70°~80°, 72°~78°, or about 75°. In this case, the angle between the polarization direction of the linearly polarized light and the slow axis direction of the λ / 4 layer 21c can be, for example, 5°~35°, 10°~20°, 12°~18°, or about 15°. Alternatively, the angle between the polarization direction of the linearly polarized light and the slow axis direction of the λ / 2 layer 21b can be, for example, 5°~35°, 10°~20°, 12°~18°, or about 15°. In this case, the angle between the polarization direction of the linearly polarized light and the slow axis direction of the λ / 4 layer 21c can be, for example, 55°~85°, 70°~80°, 72°~78°, or about 75°. The angle between the slow axis direction of the λ / 2 layer 21b and the slow axis direction of the λ / 4 layer 21c can be, for example, 50°~70°, 55°~65°, 57°~63°, or approximately 60°. The phase difference member 20 configured as described above can convert circularly polarized light incident from the second principal surface 20b side into linearly polarized light and emit it from the first principal surface 20a side.

[0134] The in-plane phase difference Re(550) of the λ / 2 layer 21b is, for example, 200nm~330nm, 230nm~330nm, 230nm~290nm, or 250nm~280nm.

[0135] The in-plane phase difference Re(550) of the λ / 4 layer 21c is, for example, 100nm~200nm, 110nm~180nm, 130nm~160nm, or 135nm~155nm.

[0136] The λ / 2 layer 21b and λ / 4 layer 21c preferably exhibit inverse dispersion wavelength characteristics, where the phase difference increases with the wavelength of the measurement light. The Re(450) / Re(550) ratios of the λ / 2 layer 21b and λ / 4 layer 21c are, for example, 0.75 or more and less than 1, and can be 0.8 or more and less than 0.95. Alternatively, the λ / 2 layer 21b and λ / 4 layer 21c can exhibit flat wavelength dispersion characteristics, where the phase difference value does not substantially change with the wavelength of the measurement light. In this case, the Re(450) / Re(550) ratios of the λ / 2 layer 21b and λ / 4 layer 21c can be, for example, 0.99 to 1.03, and the Re(650) / Re(550) ratios can be, for example, 0.98 to 1.02.

[0137] The λ / 2 layer 21b and λ / 4 layer 21c preferably exhibit a refractive index characteristic of nx > ny ≥ nz. Here, "ny = nz" not only means that ny and nz are exactly equal, but also includes the case where they are substantially equal. Therefore, there are also cases where ny < nz without impairing the effect of the present invention. The Nz coefficient of the λ / 2 layer 21b and λ / 4 layer 21c 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.

[0138] The surface smoothness of the λ / 2 layer 21b and the λ / 4 layer 21c is, for example, less than 1.00 arcmin, preferably less than 0.8 arcmin, more preferably less than 0.6 arcmin, and even more preferably less than 0.4 arcmin.

[0139] The λ / 2 layer 21b and λ / 4 layer 21c are each formed from any suitable material capable of satisfying the above-described characteristics. For example, the λ / 2 layer 21b and λ / 4 layer 21c can be stretched films of resin films or oriented cured layers of liquid crystal compounds, and their forming materials and methods can be the same as those for the λ / 4 layer 21a. When the λ / 2 layer 21b and / or λ / 4 layer 21c have flat wavelength dispersion characteristics, cycloolefin resins can be used as forming materials, with norbornene resins being preferred.

[0140] Norbornene resins are resins polymerized from norbornene monomers. Examples of norbornene monomers include: norbornene and its alkyl and / or alkylene substituents, such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, and their halogenated or other polar substituents; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc.; dimethylbridged octahydronaphthalene, etc. Its alkyl and / or alkylene substituents, as well as polar group substituents such as halogens, for example, 6-methyl-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethylene-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a- Octahydronaphthalene, 6-chloro-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-cyano-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-pyridyl-1,4:5,8-dimethylbridged-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-methoxycarbonyl-1,4:5,8-dimethylbridged-1 4,4a,5,6,7,8,8a-octahydronaphthalene, etc.; 3- to 4-quadrimers of cyclopentadiene, such as 4,9:5,8-dimethylbridged-3a,4,4a,5,8,8a,9,9a-octahydro-1H-benzo[a]indene, 4,11:5,10:6,9-trimethylbridged-3a,4,4a,5,5a,6,9,9a,10,10a,11,11a-dodecylhydro-1H-cyclopentanthene, etc. The above norbornene resins can also be copolymers of norbornene monomers with other monomers.

[0141] When the λ / 2 layer 21b is a stretched film of resin film, its thickness is, for example, 20 μm to 200 μm, preferably 20 μm to 140 μm, more preferably 20 μm to 120 μm, and even more preferably 40 μm to 100 μm. When the λ / 2 layer 21b is an orientation-cured layer of liquid crystal compound, its thickness is, for example, 2 μm to 20 μm, preferably 2 μm to 16 μm, more preferably 2 μm to 12 μm, and even more preferably 2 μm to 8 μm.

[0142] When the λ / 4 layer 21c is a stretched film of resin, its thickness is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 60 μm, and even more preferably 20 μm to 50 μm. When the λ / 4 layer 21c is an orientation-cured layer of liquid crystal compound, its thickness 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.

[0143] Within the scope of achieving the effects of the present invention, the phase retardation member 20 may further include other members. For example, in addition to the λ / 4 layer 21a, or in addition to the λ / 2 layer 21b and the λ / 4 layer 21c, the phase retardation member may also include a member capable of exhibiting a refractive index characteristic of nz>nx=ny (the so-called positive C plate). The phase difference Rth(550) in the thickness direction of the positive C plate is preferably -20nm to -200nm, more preferably -30nm to -180nm, further preferably -40nm to -160nm, and particularly preferably -50nm to -140nm. The positive C plate may, for example, have a Re(550) of less than 0.5nm, less than 0.3nm, or less than 0.1nm.

[0144] [Protective Components]

[0145] The protective member 30 includes a substrate. Typically, the protective member 30 can be a laminated film having a substrate 32 and a surface treatment layer 34. The protective member 30 having the surface treatment layer 34 can be configured such that the surface treatment layer 34 is located on the outer side (opposite to the phase retardation member 20). For example, the surface treatment layer can be located on the outermost surface of the optical laminate.

[0146] The Re (550) of the protective member 30 can be, for example, 0.1 nm or more, 0.2 nm or more, 0.5 nm or more, 0.8 nm or more, or 1 nm or more, and can also be, for example, 5.0 nm or less, or 4.0 nm or less. The Re (450) of the protective member 30 can be, for example, 0.1 nm to 5.0 nm or 0.1 nm to 4.0 nm. The Re (650) of the protective member 30 can be, for example, 0.1 nm to 5.0 nm or 0.1 nm to 4.0 nm. When using a protective member having the above-described in-plane phase difference, the ellipticity of the circularly polarized light emitted from the phase difference member changes (e.g., decreases) when passing through the protective member, but by adjusting the angle between the slow axis of the protective member and the slow axis of the phase difference layer included in the phase difference member and the polarization direction of the linearly polarized light incident on the phase difference member, the change in ellipticity can be suppressed.

[0147] For example, regarding the configuration of the phase difference component 20 that converts linearly polarized light into circularly polarized light through a λ / 4 layer, if referring to... Figure 3To explain, the angle between the polarization direction of the linearly polarized light incident from the first principal surface side of the phase difference member 20 and the slow axis direction of the protective member 30 is, for example, 15° or less (in other words, within the range of 0° ± 15°), preferably 10° or less, more preferably 5° or less, and even more preferably 3° or less, or, for example, 75° to 105° (in other words, within the range of 90° ± 15°), preferably 80° to 100°, more preferably 85° to 95°, and even more preferably 87° to 93°; the angle between the slow axis direction of the λ / 4 layer 21a and the slow axis direction of the protective member 30 is, for example, 30° to 60° (in other words, within the range of 45° ± 15°), preferably 35° to 55°, more preferably 40° to 50°, and even more preferably 42° to 48°.

[0148] Furthermore, for example, regarding the configuration of the phase difference member 20 that converts linearly polarized light into circularly polarized light through λ / 2 and λ / 4 layers, if referring to... Figure 7 To explain, the polarization direction of the linearly polarized light incident from the first principal surface side of the phase difference member 20 is, for example, 15° or less, preferably 10° or less, more preferably 5° or less, and even more preferably 3° or less, or, for example, 75° to 105°, preferably 80° to 100°, more preferably 85° to 95°, and even more preferably 87° to 93°; the angle between the slow axis direction of the λ / 4 layer 21c and the slow axis direction of the protective member 30 (wherein, in the case where the angle between the polarization direction of the linearly polarized light and the slow axis of the λ / 2 layer 21b is 55° to 85° and the angle with the slow axis of the λ / 4 layer 21c is 5° to 35°) is, for example, 60° to 90° (in other words, within the range of 75° ± 15°), preferably 65° to 85°, and more preferably 70°. ~80°, more preferably 72°~78°, or, for example, 0°~30° (in other words, within the range of 15°±15°), preferably 5°~25°, more preferably 10°~20°, and even more preferably 12°~18°; the angle between the slow axis direction of the λ / 4 layer 21c and the slow axis direction of the protective member 30 (wherein, in the case that the angle between the polarization direction of the linearly polarized light and the slow axis of the λ / 2 layer 21b is 5°~35° and the angle with the slow axis of the λ / 4 layer 21c is 55°~85°) is, for example, 0°~30°, preferably 5°~25°, more preferably 10°~20°, and even more preferably 12°~18°, or, for example, 60°~90°, preferably 65°~85°, more preferably 70°~80°, and even more preferably 72°~78°.

[0149] In both configurations described above, when an absorptive polarizing member is disposed on the first principal surface side of the phase difference member, typically, the transmission axis direction of the absorptive polarizing member is the same as the polarization direction of the linearly polarized light incident from the first principal surface side, and the absorption axis direction is orthogonal to the polarization direction of the linearly polarized light. Conversely, when a reflective polarizing member is disposed on the first principal surface side of the phase difference member, typically, the reflection axis direction of the reflective polarizing member is the same as the polarization direction of the linearly polarized light incident from the first principal surface side, and the absorption axis direction is orthogonal to the polarization direction of the linearly polarized light.

[0150] The thickness of the protective component is preferably 10μm to 80μm, more preferably 15μm to 60μm, and even more preferably 20μm to 50μm.

[0151] The substrate 32 can be composed of any suitable resin film. The substrate 32 can be a stretched resin film or a non-stretched resin film. Examples of materials that form the main component of the resin film constituting the substrate 32 include: cellulose resins such as cellulose triacetate (TAC), polyesters, polyvinyl alcohols, polycarbonates, polyamides, polyimides, polyethersulfones, polysulfones, polystyrene, polynorbornene and other cycloolefins, polyolefins, acrylics, acetates, etc. In one embodiment, the substrate 32 is preferably composed of an acrylic resin or a cellulose resin. For example, by forming these resins into films through extrusion, casting, etc., and stretching them as needed, a substrate with small in-plane phase difference and excellent surface smoothness can be obtained.

[0152] The thickness of the substrate 32 is preferably 5μm to 80μm, more preferably 10μm to 60μm, and even more preferably 20μm to 45μm.

[0153] The thickness of the surface treatment layer 34 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 34 may have, for example, a hard coating and an anti-reflective layer. The anti-reflective layer may be disposed on the outermost layer of the surface treatment layer (the outermost surface of the protective member).

[0154] In one embodiment, the surface treatment layer substantially does not have an in-plane phase difference. The Re(550) of the surface treatment layer can be, for example, less than 0.5 nm, less than 0.2 nm, or less than 0.1 nm. Therefore, the in-plane phase difference of the protective member can correspond to the in-plane phase difference of the substrate. In addition, the slow axis direction of the protective member can correspond to the slow axis direction of the substrate.

[0155] Typically, a hard coating can be formed by applying a hard coating forming material to a substrate 32 and curing the coating. Typically, the hard coating forming material contains a curable compound as a layer-forming component. Examples of curing mechanisms for the curable compound include thermosetting and photocuring types. Examples of curable compounds include monomers, oligomers, and prepolymers. It is preferable to use multifunctional monomers or oligomers as curable compounds. Examples of multifunctional 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.

[0156] The thickness of the hard coating is preferably 0.5μm to 10μm, more preferably 1μm to 7μm, and even more preferably 2μm to 5μm.

[0157] The antireflective layer preferably has a laminated structure comprising a high refractive index layer and a low refractive index layer. The antireflective layer preferably has a high refractive index layer and a low refractive index layer sequentially from the substrate 32 side.

[0158] For example, the aforementioned high refractive index layer can be composed of a high refractive index resin (e.g., with a refractive index of 1.55 or higher measured at a wavelength of 550 nm). In this case, typically, the high refractive index layer can be a coating layer. Alternatively, for example, the aforementioned high refractive index layer can be composed of an inorganic film. In this case, typically, the high refractive index layer can be formed by physical vapor deposition methods such as vacuum evaporation or sputtering, or by chemical vapor deposition methods.

[0159] The thickness of the high refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.

[0160] The thickness of the low refractive index layer is preferably 10 nm to 200 nm, and more preferably 20 nm to 150 nm.

[0161] The aforementioned low-refractive-index layer can be obtained, for example, by curing a coating film obtained by applying and drying a coating liquid for forming a low-refractive-index layer. The coating liquid for forming a low-refractive-index layer may contain, for example, resin components (curing compounds), fluorinated additives, hollow particles, solid particles, and solvents, and may be obtained by mixing these components.

[0162] Examples of curing mechanisms for the resin component (curing compound) contained in the coating liquid for forming a low refractive index layer include thermosetting and photocuring types. Examples of resin components using curing compounds having at least one of acrylate or methacrylate groups include: silicone resins, polyester resins, polyether resins, epoxy resins, urethane resins, alkyd resins, spiroacetal resins, polybutadiene resins, polythiol polyene resins, polyols, and other polyfunctional compounds such as acrylates and methacrylates, oligomers or prepolymers. These can be used individually or in combination.

[0163] The resin composition described above may also use a reactive diluent having at least one of acrylate or methacrylate groups. The reactive diluent may be, for example, the reactive diluent described in Japanese Patent Application Publication No. 2008-88309, including monofunctional acrylates, monofunctional methacrylates, polyfunctional acrylates, and polyfunctional methacrylates. From the viewpoint of obtaining excellent hardness, acrylates with three or more functional groups or methacrylates with three or more functional groups are preferred as reactive diluents. Examples of reactive diluents include butanediol glycerol ether diacrylate, acrylates of isocyanuric acid, and methacrylates of isocyanuric acid. These may be used individually or in combination. For curing the resin composition described above, a curing agent may be used. For example, a known polymerization initiator (e.g., a thermal polymerization initiator, a photopolymerization initiator, etc.) may be used as a curing agent.

[0164] The aforementioned fluorinated additives can be, for example, fluorinated organic compounds or fluorinated inorganic compounds. Examples of fluorinated organic compounds include: fluorinated antifouling coatings, fluorinated acrylic compounds, and fluorinated / silicone acrylic compounds. Commercially available products can be used as fluorinated organic compounds. Specific examples of commercially available products include: "KY-1203" manufactured by Shin-Etsu Chemical Industry Co., Ltd., and "MEGAFACE" manufactured by DIC Co., Ltd. The content of the fluorinated additive relative to 100 parts by weight of the aforementioned resin component is, 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, and can 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.

[0165] As the aforementioned hollow particles, silica particles, acrylic particles, and acrylic-styrene copolymer particles can be used, for example. Commercially available silica particles can be used (e.g., products manufactured by Nippon Chemi-Tech Chemicals Co., Ltd. under the trade names "Thrulya 5320" and "Thrulya 4320"). The weight-average particle size of the hollow particles can 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 can 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 a generally spherical shape is preferred. Specifically, the aspect ratio of the hollow particles is preferably 1.5 or less. The content of hollow particles relative to 100 parts by weight of the above-mentioned resin components is, 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 it can be less than 300 parts by weight, less than 270 parts by weight, less than 250 parts by weight, less than 200 parts by weight, or less than 180 parts by weight.

[0166] As the aforementioned solid particles, materials such as silica particles, zirconium oxide particles, and carbon dioxide particles can be used. Commercially available silica particles can be used (e.g., products manufactured by Nissan Chemical Industries, Ltd. under the trade names "MEK-2140Z-AC", "MIBK-ST", and "IPA-ST"). The weight-average particle size of the solid particles can 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 can 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 relative to 100 parts by weight of the aforementioned resin component is, 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, and can 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.

[0167] Any suitable solvent can be used as the solvents mentioned above. Examples of solvents include: alcohols such as methanol, ethanol, isopropanol, butanol, TBA (tert-butanol), 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; diols such as ethylene glycol and propylene glycol; cellosolvers such as ethyl cellosolvers and butyl cellosolvers; aliphatic hydrocarbons such as hexane, heptane, and octane; and aromatic hydrocarbons such as benzene, toluene, and xylene. One of these can be used alone, or two or more can be used in combination. Regarding the content of the solvent, it can be set such that the weight of the solid component relative to the total weight of the coating liquid for forming the low refractive index layer 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 it can be set such that it is 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.

[0168] The coating method for the coating liquid used to form the aforementioned low refractive index layer can be, for example, a known coating method such as overflow coating, die coating, spin coating, spray coating, gravure coating, roller coating, or 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 curing of the coating can be performed, for example, by heating or light irradiation (typically, ultraviolet irradiation). A high-pressure mercury lamp can be used as the light source for irradiation. The irradiation dose of the ultraviolet light is preferably 50 mJ / cm², based on the cumulative exposure at an ultraviolet wavelength of 365 nm. 2 ~500mJ / cm 2 .

[0169] [Absorption-type polarization component]

[0170] Typically, the absorptive polarizing elements 10 and 15 may comprise a resin film containing a dichroic substance (sometimes referred to as an absorptive polarizing film). The thickness of the absorptive polarizing film may be, for example, 1 μm or more and 20 μm or less, 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. A protective layer may be provided on one or both sides of the absorptive polarizing film.

[0171] The aforementioned absorptive polarizing film can be made from a single layer of resin film or from a laminate of two or more layers.

[0172] In the case of a single-layer resin film, for example, an absorptive polarizing film can be obtained by subjecting hydrophilic polymer films such as polyvinyl alcohol (PVA) films, partially formalized PVA films, and partially saponified ethylene / vinyl acetate copolymer films to dyeing treatments using dichroic substances such as iodine and dichroic dyes, and stretching treatments. Among these, an absorptive polarizing film obtained by dyeing a PVA film with iodine and then uniaxially stretching it is preferred.

[0173] The aforementioned iodine-based dyeing can be performed, for example, by immersing the PVA film in an aqueous iodine solution. The preferred stretching ratio for the uniaxial stretching is 3 to 7 times. Stretching can be performed after dyeing or simultaneously with dyeing. Alternatively, dyeing can be performed after stretching. Swelling treatment, crosslinking treatment, cleaning treatment, drying treatment, etc., can be applied to the PVA film as needed.

[0174] Examples of laminates made using two or more layers include a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a resin substrate and a PVA-based resin layer coated on the resin substrate. An absorptive polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be manufactured by: for example, coating a PVA-based resin solution onto a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, obtaining a laminate of the resin substrate and the PVA-based resin layer; stretching and dyeing the laminate to form an absorptive polarizing film from the PVA-based resin layer. In this embodiment, it is preferable to form a polyvinyl alcohol resin layer comprising a halide and a polyvinyl alcohol resin on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution for stretching. Furthermore, stretching may, as needed, further include stretching the laminate in a gas atmosphere at a high temperature (e.g., 95°C or higher) before stretching in the aqueous boric acid solution. Furthermore, in this embodiment, it is preferable to subject the laminate to a drying shrinkage treatment, which causes it to shrink by more than 2% in the width direction by heating while being transported along the length direction. Typically, the manufacturing method of this embodiment includes sequentially subjecting the laminate to assisted stretching in a gas atmosphere, dyeing, stretching in an aqueous solution, and drying shrinkage treatment. By introducing assisted stretching, even when PVA is coated on a thermoplastic resin, the crystallinity of PVA can be improved, achieving high optical properties. Additionally, by simultaneously improving the orientation of PVA beforehand, problems such as decreased orientation and dissolution of PVA during subsequent dyeing and stretching processes when immersed in water can be prevented, achieving high optical properties. Furthermore, when the PVA-type resin layer is immersed in a liquid, compared to when the PVA-type resin layer does not contain halides, the orientation disorder of polyvinyl alcohol molecules and the reduction of orientation can be suppressed. Therefore, the optical properties of the absorptive polarizing film obtained by immersing the laminate in a liquid through dyeing and stretching processes in an aqueous solution can be improved. Furthermore, by drying and shrinking the laminate in the width direction, optical properties can be improved. The resulting resin substrate / absorbent polarizing film laminate can be used directly (i.e., the resin substrate can be used as a protective layer for the absorbent polarizing film), or the resin substrate can be peeled off from the resin substrate / absorbent polarizing film laminate, and any suitable protective layer corresponding to the purpose can be laminated on the peeled surface or on the side opposite to the peeled surface. Detailed descriptions 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.

[0175] The orthogonal transmittance (Tc) of the absorptive polarizing element (absorption polarizing film) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The unit transmittance (Ts) of the absorptive polarizing element (absorption polarizing film) is, for example, 41.0% to 45.0%, preferably 42.0% or more. The degree of polarization (P) of the absorptive polarizing element (absorption polarizing film) is, for example, 99.0% to 99.997%, preferably 99.9% or more.

[0176] [Reflective polarization component]

[0177] The reflective polarizing member 14 allows polarized light parallel to its transmission axis (typically linearly polarized light) to pass through while maintaining its polarization state, and reflects light with other polarization states (typically light orthogonal to its transmission axis). Typically, the reflective polarizing member is composed of a film with a multilayer structure (sometimes called 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.

[0178] Commercially available reflective polarizing films include, for example, those manufactured by 3M under the brand names "DBEF" and "APF", and those manufactured by Nitto Denko Corporation under the brand name "APCF".

[0179] The orthogonal transmittance (Tc) of the reflective polarizing element (reflective polarizing film) can be, for example, 0.01% to 3%. The single-unit transmittance (Ts) of the reflective polarizing element (reflective polarizing film) is, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of the reflective polarizing element (reflective polarizing film) can be, for example, 92% to 99.99%.

[0180] [Adhesive layer]

[0181] The adhesive layer 40 can be composed of any suitable adhesive. Specific examples include acrylic adhesives, rubber adhesives, silicone adhesives, polyester adhesives, urethane adhesives, epoxy adhesives, and polyether adhesives. By adjusting the type, quantity, combination, and proportion of monomers in the base resin forming the adhesive, as well as the amount of crosslinking agent, reaction temperature, and reaction time, an adhesive with desired properties corresponding to the target can be prepared. The base resin of the adhesive can be used alone or in combination of two or more. Acrylic resins are preferably used as the base resin. Specifically, the adhesive layer 40 is preferably composed of an acrylic adhesive.

[0182] The thickness of the adhesive layer 40 is, for example, 12 μm or more, preferably 15 μm or more, for example, 100 μm or less, preferably 80 μm or less.

[0183] [Adhesive layer]

[0184] The adhesive layers 50a-d can be formed by an adhesive or a binder. Specifically, the adhesive layers can be either an adhesive layer or a binder layer. The thickness of the adhesive layers is, for example, 0.01 μm to 60 μm. In one embodiment, the phase difference member 20 and the protective member 30 are bonded together via the adhesive layer. The same description as for the adhesive layer 40 can be applied to the adhesive layer when it is a binder layer.

[0185] B. Display System

[0186] Figure 8 This is a schematic diagram illustrating a simplified configuration of a display system that can utilize the optical laminate described in section A. Figure 8 The diagram schematically illustrates the configuration and shape of the various components of the display system 2. The display system 2 includes a display element 12, a reflective polarizing member 14, a first lens portion 16, a semi-reflective mirror 18, a first phase difference member 22, a second phase difference member 23, and a second lens portion 24. The reflective polarizing member 14 is disposed on the display surface 12a side of the display element 12, i.e., in front, and is capable of reflecting light emitted from the display element 12. The first lens portion 16 is disposed in the optical path between the display element 12 and the reflective polarizing member 14, and the semi-reflective mirror 18 is disposed between the display element 12 and the first lens portion 16. The first phase difference member 22 is disposed in the optical path between the display element 12 and the semi-reflective mirror 18, and the second phase difference member 23 is disposed in the optical path between the semi-reflective mirror 18 and the reflective polarizing member 14. The first phase difference member 22 and the second phase difference member 23 are capable of converting linearly polarized light into circularly polarized light, or vice versa. Although not shown in the figure, from the viewpoint of improving visual recognition, an absorptive polarizing member can be disposed between the reflective polarizing member 14 and the second lens portion 24. In this case, the reflection axis of the reflective polarizing member 14 and the absorption axis of the absorptive polarizing member can 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 can be arranged substantially parallel to each other.

[0187] Sometimes the components arranged in front of the semi-reflecting mirror or the first lens section (in the example shown, the semi-reflecting mirror 18, the first lens section 16, the second phase difference member 23, the reflective polarizing member 14, and the second lens section 24) are collectively referred to as the lens section (lens section 4).

[0188] The display element 12 is, for example, a liquid crystal display or an organic EL display, having a display surface 12a for displaying images. 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 then emitted as first linearly polarized light.

[0189] The first linearly polarized light incident on the first phase difference member 22 is converted into the first circularly polarized light. The first phase difference member 22 can be integrally disposed on the display element 12. For example, the first phase difference member 22 can be integrally disposed with a polarization member that may be included in the display element 12.

[0190] The semi-reflective mirror 18 allows light emitted from the display element 12 to pass through and causes light reflected by the reflective polarizing member 14 to be reflected back towards the reflective polarizing member 14. The semi-reflective mirror 18 is integrally provided with the first lens section 16.

[0191] The second phase difference member 23 allows light reflected by the reflective polarizer 14 and the half-reflector 18 to pass through the reflective polarizer 14. The second phase difference member 23 can be integrally disposed on the first lens portion 16 or the second lens portion 24. In the latter case, the second phase difference member 23 can be integrally disposed on the second lens portion 24 together with the reflective polarizer 14.

[0192] The first circularly polarized light emitted from the first phase difference member 22 passes through the half-reflector 18 and the first lens section 16, and is converted into second linearly polarized light by the second phase difference member 23. The second linearly polarized light emitted from the second phase difference member 23 does not pass through the reflective polarizing member 14 and is reflected back to the half-reflector 18. 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. Therefore, the second linearly polarized light incident on the reflective polarizing member 14 is reflected by the reflective polarizing member 14.

[0193] The second linearly polarized light, after being reflected by the reflective polarizing member 14, is converted into second circularly polarized light by the second phase difference member 23. The second circularly polarized light emitted from the second phase difference member 23 passes through the first lens section 16 and is reflected by the half-reflecting mirror 18. The circularly polarized light reflected by the half-reflecting mirror 18 passes through the first lens section 16 and is converted into third linearly polarized light by the second phase difference member 23. The third linearly polarized light passes 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 the same as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light incident on the reflective polarizing member 14 will pass through the reflective polarizing member.

[0194] Light that has passed through the reflective polarizing member 14 enters the user's eye 26 through the second lens section 24.

[0195] 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 can be arranged in a manner that is substantially parallel to each other, or in a manner that is substantially orthogonal to each other.

[0196] In one embodiment, the optical stack described in item A can be applied to the display system 2 as an optical stack including the first phase difference member 22. In this embodiment, the optical stack described in item A is disposed behind the semi-reflective mirror 18, such that the second principal surface 20b of the phase difference member 20 becomes the side of the semi-reflective mirror 18, thereby the phase difference member 20 can function as the first phase difference member 22.

[0197] For example, such as Figure 9 As shown, by bonding the optical laminate 100B to the component 13 constituting the display element using the adhesive layer 40, a display system integrating the first phase difference component 22 and the display element 12 can be formed. In this display system, the absorptive polarizing component 10 is a polarizing component that can be included in the display element 12, and the light emitted from the absorptive polarizing component 10 becomes first linearly polarized light. The first linearly polarized light is converted into first circularly polarized light by the first phase difference component 22, and can maintain a high ellipticity even after passing through the protective component 30. As a result, polarization disorder in the display system is suppressed, and visual recognition can be improved.

[0198] In one embodiment, the optical stack described in item A can be applied to the display system 2 as an optical stack including the second phase difference member 23. In this embodiment, the optical stack described in item A is disposed in front of the semi-reflective mirror 18 (but behind the second lens portion 24), such that the second principal surface 20b of the phase difference member 20 becomes the side of the semi-reflective mirror 18, thereby the phase difference member 20 can function as the second phase difference member 23.

[0199] For example, such as Figure 10 As shown, by bonding the optical laminate 100C to the second lens portion 24 using the adhesive layer 40, a display system integrating the second phase difference member 23 and the second lens portion 24 can be constructed. In the lens portion 4 of this display system, the second linearly polarized light emitted from the second phase difference member 23 toward the reflective polarization member 14 is reflected by the reflective polarization member 14 and incident from the first principal surface side 20a onto the second phase difference member 23, where it is converted into second circularly polarized light. The second circularly polarized light emitted from the second principal surface 20b of the second phase difference member 23 can also maintain a high ellipticity after passing through the protective member 30. As a result, polarization disorder in the display system is suppressed, and visual recognition can be improved.

[0200] In one embodiment, the optical stack described in item A can be used in the display system 2 as an optical stack including a second phase difference member 23. The optical stack used in this embodiment includes a phase difference member 20 configured to convert linearly polarized light into circularly polarized light through a λ / 4 layer. The optical stack is positioned in front of the semi-reflective mirror 18 such that the first principal surface 20a of the phase difference member 20 is on the side of the semi-reflective mirror 18, thereby allowing the phase difference member 20 to function as a second phase difference member 23.

[0201] For example, such as Figure 11 As shown, by bonding the optical laminate 100A to the first lens portion 16 using the adhesive layer 40, a display system integrating the second phase difference member 23 and the first lens portion 16 can be constructed (in the example shown, the reflective polarizing member 14 is integrated with the second lens portion 24 via the adhesive layer 50e). In the lens portion 4 of this display system, first circularly polarized light emitted from the first phase difference member 22 is incident from the first principal surface side 20a onto the second phase difference member 23 and converted into second linearly polarized light. The second linearly polarized light emitted from the second principal surface 20b of the second phase difference member 23 can also maintain its polarization state after passing through the protective member 30 (in other words, changes in ellipticity can be suppressed). In addition, circularly polarized light reflected by the semi-reflective mirror is incident from the first principal surface side 20a onto the second phase difference member 23 and converted into third linearly polarized light. The third linearly polarized light emitted from the second principal surface 20b of the second phase difference member 23 can also maintain its polarization state after passing through the protective member 30. As a result, the polarization disorder in the display system is suppressed, which can improve visual recognition.

[0202] Example

[0203] The present invention will now be described in detail with reference to specific embodiments, but the present invention is not limited to these embodiments in any way. It should be noted that the testing and evaluation methods in the embodiments, etc., are as follows. Wherein, when "parts" are used, unless otherwise specified, it means "parts by weight"; when "%" are used, unless otherwise specified, it means "% by weight".

[0204] (1) Thickness

[0205] Thicknesses below 10 μm were measured using a scanning electron microscope (manufactured by Nippon Electron Ltd., product name "JSM-7100F"). Thicknesses exceeding 10 μm were measured using a digital micrometer (manufactured by Anritsu Ltd., product name "KC-351C").

[0206] (2) Phase difference

[0207] The phase difference at a given wavelength was measured using a phase difference / elliptic polarization measurement device (manufactured by Oji Measurement Equipment Co., Ltd., product name "KOBRA-HBR", "KOBRA-HBPR") at 23°C.

[0208] (3) Individual transmittance and degree of polarization of polarizing components

[0209] The individual transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of the polarizing element were measured using a spectrophotometer (manufactured by Otsuka Electronics Co., Ltd., "LPF-200"). These Ts, Tp, and Tc values ​​were Y values ​​measured using a 2-degree field of view (C light source) with JIS Z8701 and corrected for visibility. Based on the obtained Tp and Tc, the degree of polarization of the polarizing element was calculated using the following formula.

[0210] Degree of polarization (%) = {(Tp-Tc) / (Tp+Tc)} 1 / 2 ×100

[0211] (4) Smoothness

[0212] Smoothness was measured using a phase-shifted laser interferometer (Zygo Corporation, product name "DynaFiz"). Specifically, the test object was laminated onto a microscope slide (Matsunami Glass Industry Co., Ltd., product name "S200200") to prevent the introduction of foreign matter, air bubbles, or deformed streaks. Next, to remove the influence of tiny air bubbles, degassing was performed using a pressure degassing device (autoclave). The degassing conditions were set at 50°C, 0.5 MPa, and 30 minutes.

[0213] After degassing, the sample was allowed to cool naturally at room temperature for at least 30 minutes to obtain the test sample. The test sample was placed on a measuring stage equipped with a vibration damping platform, and the relative displacement within a given region (a circle with a diameter of 30 mm) was measured by interfering with a single-wavelength laser (wavelength 633 nm) with a reference device that ensured flatness.

[0214] Regarding the analysis, the value obtained by multiplying the angle index "SlopemagnitudeRMS" obtained by extracting the frequency values ​​from 0.1 / mm to 1 / mm by 2 (equivalent to 2σ) is defined as smoothness (unit: arcmin).

[0215] (5) Axis angle

[0216] The axial angle was measured using a Mueller matrix polarization measuring instrument (manufactured by AXOMETRICS, product name "AxoScan") at a measurement wavelength of 550 nm.

[0217] [Manufacturing Example 1: Fabrication of Absorption-Type Polarizing Component A]

[0218] (Fabrication of Absorption-Type Polarizing Film)

[0219] As a thermoplastic resin substrate, a strip-shaped amorphous polyethylene terephthalate copolymer film (thickness: 100 μm) with a Tg of about 75 °C was used to apply corona treatment to one side of the resin substrate.

[0220] A PVA aqueous solution (coating solution) was prepared by adding 13 parts by weight of potassium iodide to 100 parts by weight of a PVA resin prepared by mixing polyvinyl alcohol (degree of polymerization 4200, degree of saponification 99.2 mol%) and acetoacetyl-modified PVA (manufactured by Mitsubishi Chemical Corporation, trade name "GOHSENX Z410") in a 9:1 ratio, and dissolving the resulting mixture in water.

[0221] The above-mentioned PVA aqueous solution was coated on the corona-treated surface of the resin substrate and dried at 60°C, thereby forming a PVA resin layer with a thickness of 13 μm and producing a laminate.

[0222] The resulting laminate was stretched unidirectionally along the longitudinal direction (length direction) to 2.4 times in an oven at 130°C (assisted stretching treatment in a gas atmosphere).

[0223] Next, the laminate is immersed in an insoluble bath (an aqueous solution of boric acid prepared by mixing 4 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (insoluble treatment).

[0224] Next, to achieve the desired monomer transmittance (Ts) of the final absorptive polarizing film, the concentration was adjusted while immersing the film in a staining bath (an iodine aqueous solution prepared by mixing iodine and potassium iodide in a weight ratio of 1:7 relative to 100 parts by weight of water) at a liquid temperature of 30°C for 60 seconds (staining treatment).

[0225] Next, it is immersed in a crosslinking bath (an aqueous solution of boric acid prepared by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) at a liquid temperature of 40°C for 30 seconds (crosslinking treatment).

[0226] Then, while immersing the laminate in a boric acid aqueous solution (boric acid concentration 4 wt%, potassium iodide concentration 5 wt%) at a liquid temperature of 70°C, it is unidirectionally stretched (stretching treatment in aqueous solution) between rollers with different circumferential speeds along the longitudinal direction (length direction) to achieve a total stretch ratio of 5.5.

[0227] Then, the laminate was immersed in a cleaning bath at a liquid temperature of 20°C (an aqueous solution of 100 parts by weight of water and 4 parts by weight of potassium iodide) (cleaning treatment).

[0228] Then, while drying in an oven maintained at approximately 90°C, the laminate is subjected to drying on SUS heated rollers with the contact surface temperature maintained at approximately 75°C (drying shrinkage treatment). The width-direction shrinkage rate of the laminate based on the drying shrinkage treatment is 5.2%.

[0229] Thus, an absorptive polarizing film with a thickness of approximately 5 μm was formed on the resin substrate.

[0230] (Fabrication of absorption-type polarization components)

[0231] As a protective layer, a 20 μm thick acrylic film with an lactone ring structure is bonded to the surface (opposite to the resin substrate) of the obtained absorptive polarizing film using a UV-curable adhesive. Specifically, the adhesive is applied with a thickness of 2 μm and bonded using a roller. Then, UV light is irradiated from the acrylic film side to cure the adhesive. Next, the resin substrate is peeled off. This yields an absorptive polarizing member A with a [acrylic film / absorptive polarizing film] configuration. The absorptive polarizing member A has a monomer transmittance (Ts) of 43.4% and a polarization degree of 99.993%.

[0232] [Manufacturing Example 2A: Construction of λ / 4 Layer A]

[0233] A batch polymerization unit consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled at 100°C was fed with 29.60 parts by weight (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluorene-9-yl]methane, 29.21 parts by weight (0.200 mol) of isosorbide (ISB), 42.28 parts by weight (0.139 mol) of spirodiol (SPG), 63.77 parts by weight (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10⁻⁶ mol of calcium acetate monohydrate as a catalyst. -2 Parts by weight (6.78 × 10) -5 mol).

[0234] After purging the reactor with nitrogen under reduced pressure, it was heated using a heat transfer medium, and stirring was initiated when the internal temperature reached 100°C. The internal temperature reached 220°C 40 minutes after the start of heating. While maintaining this temperature, pressure was reduced, and the pressure reached 13.3 kPa after 90 minutes. Phenolic vapors, a byproduct of the polymerization reaction, were introduced into a 100°C reflux condenser, allowing some of the monomer components in the phenol vapors to return to the reactor, while the uncondensed phenol vapors were recovered in a 45°C condenser. Nitrogen was introduced into the first reactor to temporarily restore atmospheric pressure, and the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Then, heating and depressurization were initiated in the second reactor, reaching an internal temperature of 240°C and a pressure of 0.2 kPa after 50 minutes.

[0235] The polymerization is then carried out until a given stirring power is reached. At the moment the given power is reached, nitrogen is introduced into the reactor to restore pressure, the generated polyester carbonate resin is extruded into water, and the filament is cut into granules.

[0236] The obtained polyester carbonate resin (granules) was vacuum dried at 80°C for 5 hours. A 130μm thick elongated resin film was then produced using a film-forming apparatus equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder set temperature: 250°C), a T-die (width 200mm, set temperature: 250°C), chilled rolls (set temperature: 120~130°C), and a winding machine. The resulting elongated resin film was stretched along its width at a stretching temperature of 140°C and a stretch ratio of 2.7, and then wound into a roll.

[0237] Thus, a λ / 4 layer A with a thickness of 47 μm was obtained. The Re(450) of the λ / 4 layer A is 119 nm, the Re(550) is 139 nm, and the Re(650) is 147 nm, exhibiting inverse dispersion wavelength characteristics. The Nz coefficient (590) of the λ / 4 layer A is 1.2. In addition, the smoothness of the λ / 4 layer A is 0.25 arcmin.

[0238] [Manufacturing Example 2B: Construction of Layer B (λ / 4)]

[0239] By adjusting the stretching ratio and stretching temperature to achieve an in-plane phase difference Re(590) of 135 nm, a long strip of norbornene resin film (manufactured by Zeon Corporation, Japan, trade name "Zeonor", thickness 40 μm) was longitudinally stretched from its free end, thereby fabricating a 34 μm thick λ / 4 layer B. The λ / 4 layer B exhibits a refractive index characteristic of nx > ny = nz. Furthermore, the Re(450) / Re(550) ratio of the λ / 4 layer B is 1.004, showing a generally flat dispersive wavelength characteristic. Additionally, the surface smoothness of the λ / 4 layer B is 0.32 arcmin.

[0240] [Manufacturing Example 2C: Construction of λ / 2 Layer A]

[0241] By adjusting the stretching ratio and stretching temperature to achieve an in-plane phase difference Re(590) of 280 nm, a long strip of norbornene resin film (manufactured by Zeon Corporation, Japan, trade name "Zeonor", thickness 50 μm) was longitudinally stretched from its free end, thereby fabricating a 32 μm thick λ / 2 layer A. λ / 2 layer A exhibits a refractive index characteristic of nx > ny = nz. Furthermore, the Re(450) / Re(550) ratio of λ / 2 layer A is 1.004, showing a generally flat dispersive wavelength characteristic. Additionally, the surface smoothness of λ / 2 layer A is 0.42 arcmin.

[0242] [Manufacturing Example 3A: Fabrication of Protective Component A]

[0243] (Preparation of hard coating forming materials)

[0244] A hard coating 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 with pentaerythritol triacrylate as the main component (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat#300"), 20 parts of 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1 part of leveling agent (manufactured by DIC Corporation, "GRANDICPC4100"), and 3 parts of photopolymerization initiator (manufactured by Ciba Japan Corporation, "Irgacure907"), and diluting with methyl isobutyl ketone to achieve a solid component concentration of 50%.

[0245] (Preparation of coating solution for forming high refractive index layer)

[0246] 100 parts by weight of multifunctional acrylate (manufactured by Arakawa Chemical Industry Co., Ltd., trade name "OPSTAR KZ6728", solid content 20% by weight), 3 parts by weight of leveling agent (manufactured by DIC, "GRANDICPC4100"), and 3 parts by weight of photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100% by weight) were mixed together.

[0247] For this mixture, butyl acetate was used as a diluent to make the solid content 12% by weight, and the mixture was stirred to prepare a coating solution for forming a high refractive index layer.

[0248] (Preparation of coating solution for forming low refractive index layer)

[0249] 100 parts by weight of a multifunctional acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat#300", solid content 100 wt%), mainly composed of pentaerythritol triacrylate; 150 parts by weight of hollow nano-silica particles (manufactured by Nichibukai Chemical Industry Co., Ltd., trade name "Thrulya5320", solid content 20 wt%, weight average particle size 75 nm); 50 parts by weight of solid nano-silica particles (manufactured by Nissan Chemical Industry Co., Ltd., trade name "MEK-2140Z-AC", solid content 30 wt%, weight average particle size 10 nm); 12 parts by weight of a fluorinated additive (manufactured by Shin-Etsu Chemical Industry Co., Ltd., trade name "KY-1203", solid content 20 wt%); and 3 parts by weight of a photopolymerization initiator (manufactured by BASF, trade name "OMNIRAD907", solid content 100 wt%) were mixed together.

[0250] A mixed solvent consisting of TBA (tert-butanol), MIBK (methyl isobutyl ketone), and PMA (propylene glycol monomethyl ether acetate) in a weight ratio of 60:25:15 was added to the mixture as a diluent, so that the total solid content was 4% by weight. The mixture was stirred to prepare a coating liquid for forming a low refractive index layer.

[0251] The aforementioned hard coating material was coated onto an acrylic film (40 μm thick) with an lactone ring structure, heated at 90°C for 1 minute, and then irradiated with a high-pressure mercury lamp to accumulate a light intensity of 300 mJ / cm². 2 The ultraviolet light cured the coating, producing an acrylic film with a hard coating of 4 μm thickness (44 μm thickness, surface smoothness of 0.4 arcmin on the hard coating side).

[0252] Next, the high-refractive-index layer forming liquid was applied to the hard coating using a wire rod. The applied liquid was then heated at 80°C for 1 minute to dry, forming a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp, accumulating a light intensity of 300 mJ / cm². 2 The ultraviolet light causes the coating to cure, forming a high refractive index layer with a thickness of 140nm.

[0253] Next, the coating solution for forming the low refractive index layer was applied onto the high refractive index layer using a wire rod. The applied coating solution was then heated at 80°C for 1 minute to dry, forming a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp, accumulating a light intensity of 300 mJ / cm². 2 The ultraviolet light causes the coating to cure, forming a low refractive index layer with a thickness of 105 nm.

[0254] As described above, a protective component A with the structure of [acrylic film / hard coating / high refractive index layer / low refractive index layer] was obtained. The thickness of the protective component A is 44 μm, and the surface smoothness is 0.4 arcmin. In addition, the Re(450), Re(550), and Re(650) of the protective component A are 2.2 nm, 1.8 nm, and 1.7 nm, respectively.

[0255] [Manufacturing Example 3B: Fabrication of Protective Component B]

[0256] A hard coating forming material identical to that used in Manufacturing Example 3A was coated onto a cellulose triacetate membrane (manufactured by Fujifilm Corporation, trade name "TG60UL", thickness 60 μm), and heated at 90°C for 1 minute. The heated coating was then irradiated with a high-pressure mercury lamp, accumulating a light intensity of 300 mJ / cm². 2 Ultraviolet light was used to cure the coating, resulting in a cellulose triacetate membrane (72 μm thick) with a hard coating of 12 μm thickness.

[0257] Next, using a wire rod, a high-refractive-index layer forming coating liquid, identical to that used in Manufacturing Example 3A, was applied to the aforementioned hard coating layer. The applied coating liquid was then heated at 80°C for 1 minute to dry, forming a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp, accumulating a light intensity of 300 mJ / cm². 2 The ultraviolet light causes the coating to cure, forming a high refractive index layer with a thickness of 140nm.

[0258] Next, using a wire rod, a low-refractive-index layer forming coating solution, identical to that used in Manufacturing Example 3A, was applied onto the high-refractive-index layer. The coated solution was then heated at 80°C for 1 minute to dry, forming a coating film. The dried coating film was then irradiated with a high-pressure mercury lamp, accumulating a light intensity of 300 mJ / cm². 2 The ultraviolet light causes the coating to cure, forming a low refractive index layer with a thickness of 105 nm.

[0259] As described above, a protective component B with a structure of [TAC film / hard coating / high refractive index layer / low refractive index layer] was obtained. The thickness of the protective component B is 72 μm, and the surface smoothness is 0.9 arcmin. In addition, the Re(450), Re(550), and Re(650) of the protective component B are 0.2 nm, 1.1 nm, and 1.4 nm, respectively.

[0260] [Examples 1-1 to 1-3, Comparative Examples 1-1 to 1-3, Reference Example 1]

[0261] The absorptive polarizing member A, λ / 4 layer A, and protective member A fabricated in the above manufacturing example were punched into rectangles such that the optical axis is at a given angle relative to the side direction. They were then stacked in the manner shown in Table 1 with the configuration and axial angles to create an optical laminate. In this case, the absorptive polarizing member A and λ / 4 layer A were laminated using an acrylic adhesive (5 μm thick), with the absorptive polarizing film side surface of the absorptive polarizing member A facing the λ / 4 layer A. Furthermore, the λ / 4 layer A and protective member A were laminated using an acrylic adhesive (12 μm thick), with the substrate side surface of the protective member A facing the λ / 4 layer A. Additionally, an optical laminate without the protective member A was fabricated as Reference Example 1.

[0262]

[0263] [Examples 2-1~2-3, Comparative Examples 2-1~2-3]

[0264] The absorptive polarizing member A, λ / 4 layer A, and protective member B, fabricated in the above manufacturing example, were punched into rectangles such that the optical axis is at a given angle relative to the edge direction. They were then stacked in the manner shown in Table 2, resulting in an optical laminate. In this case, the absorptive polarizing member A and λ / 4 layer A were laminated using an acrylic adhesive (5 μm thick), with the absorptive polarizing film side surface of the absorptive polarizing member A facing the λ / 4 layer A. Similarly, the λ / 4 layer A and protective member B were laminated using an acrylic adhesive (12 μm thick), with the substrate side surface of the protective member B facing the λ / 4 layer A.

[0265]

[0266] For the A-side surface of the absorption polarizing member of the optical laminates obtained in Examples 1-1 to 2-3, Comparative Examples 1-1 to 2-3, and Reference Example 1, the ellipticity of the light emitted from the opposite surface (polar angle 0°) at wavelengths of 450 nm, 550 nm, and 650 nm was measured using a Mueller matrix polarization meter (manufactured by AXOMETRICS, product name "AxoScan") with light incident from the front direction. The difference between the ellipticity measured for each optical laminate and the ellipticity measured for the optical laminate of Reference Example 1 (ellipticity in Reference Example 1 - ellipticity in the examples or comparative examples) is shown below. Figure 12 and 13 .

[0267] It should be noted that the ellipticity of the emitted light at wavelengths of 450 nm, 550 nm and 650 nm, as measured with respect to the optical laminate of Reference Example 1, is 0.908, 0.983 and 0.860, respectively.

[0268] like Figure 12 As shown, in the optical laminates of Comparative Examples 1-1 to 1-3, the change in ellipticity of the transmitted light (emitted light) compared to the optical laminate of Reference Example 1 exceeded 0.02 depending on the wavelength. However, in the optical laminates of Examples 1-1 to 1-3, it was suppressed to below 0.02 at any wavelength. Furthermore, as... Figure 13 As shown, in the optical stacks of Comparative Examples 2-1 to 2-3, the change in the ellipticity of transmitted light compared to the optical stack of Reference Example 1 exceeded 0.01 depending on the wavelength. However, in the optical stacks of Examples 2-1 to 2-3, the change was suppressed to less than 0.01 at any wavelength. In summary, for the optical stacks of the embodiments, compared to the optical stacks of the comparative examples, the change in the ellipticity of transmitted light compared to the reference examples was further suppressed.

[0269] [Examples 3-1 to 3-3, Comparative Examples 3-1 to 3-3, Reference Example 2]

[0270] The absorptive polarizing member A, λ / 2 layer A, λ / 4 layer B, and protective member A fabricated in the above manufacturing example were punched into rectangles, with the optical axis at a given angle relative to the edge direction. They were then stacked in the manner shown in Table 3, resulting in an optical laminate. In this case, the absorptive polarizing member A and λ / 2 layer A were laminated using an acrylic adhesive (5 μm thick), with the absorptive polarizing film side surface of the absorptive polarizing member A facing the λ / 2 layer A. The λ / 2 layer A and λ / 4 layer B were laminated using an acrylic adhesive (5 μm thick). The λ / 4 layer B and protective member A were laminated using an acrylic adhesive (12 μm thick), with the substrate side surface of the protective member A facing the λ / 4 layer B. Additionally, an optical laminate without the protective member A was fabricated as Reference Example 2.

[0271]

[0272] [Examples 4-1 to 4-3, Comparative Examples 4-1 to 4-3]

[0273] Except that protective component B was used instead of protective component A, optical laminates with the configuration and axial angles shown in Table 4 were fabricated in the same manner as Examples 3-1 to 3-3 and Comparative Examples 3-1 to 3-3.

[0274]

[0275] For the A-side surface of the absorption polarizing member of the optical laminates obtained in Examples 3-1 to 4-3, Comparative Examples 3-1 to 4-3, and Reference Example 2, the ellipticity of the light emitted from the opposite surface (polar angle 0°) at wavelengths of 450 nm, 550 nm, and 650 nm was measured using a Mueller matrix polarization meter (manufactured by AXOMETRICS, product name "AxoScan") with light incident from the front direction. The difference between the ellipticity measured for each optical laminate and the ellipticity measured for the optical laminate of Reference Example 2 (ellipticity in Reference Example 2 - ellipticity in the examples or comparative examples) is shown below. Figure 14 and 15 .

[0276] It should be noted that the ellipticity of the emitted light at wavelengths of 450 nm, 550 nm, and 650 nm, as measured with respect to the optical laminate of Reference Example 2, is 0.873, 0.944, and 0.934, respectively.

[0277] like Figure 14As shown, in the optical laminates of Comparative Examples 3-1 to 3-3, the change in ellipticity of the transmitted light (emitted light) compared to the optical laminate of Reference Example 2 exceeded 0.02 depending on the wavelength, but in the optical laminates of Examples 3-1 to 3-3, it was suppressed to below 0.02 at any wavelength. Furthermore, as... Figure 15 As shown, in the optical stacks of Comparative Examples 4-1 to 4-3, the change in the ellipticity of transmitted light compared to the optical stack of Reference Example 2 exceeded 0.01 depending on the wavelength. However, in the optical stacks of Examples 4-1 to 4-3, the change was suppressed to less than 0.01 at any wavelength. In summary, for the optical stacks of the embodiments, compared to the optical stacks of the comparative examples, the change in the ellipticity of transmitted light compared to the reference examples was further suppressed.

[0278] This invention is not limited to the embodiments described above, and various modifications can be made. For example, it can be replaced with a configuration that is substantially the same as the configuration shown in the above embodiments, a configuration that can perform the same function, or a configuration that can achieve the same purpose.

[0279] Industrial applicability

[0280] The display system of the present invention can be used in displays such as VR goggles.

Claims

1. An optical laminate comprising: A phase difference component having a first principal surface and a second principal surface opposite to each other, and converting linearly polarized light incident from the first principal surface side into circularly polarized light and exiting from the second principal surface side; and A protective member having a slow axis and disposed on the second principal surface side of the phase difference member. The angle between the slow axis of the protective component and the polarization direction of the linearly polarized light is less than 15° or between 75° and 105°.

2. The optical laminate according to claim 1, wherein, The phase difference component comprises a λ / 4 layer of Re(550) with a wavelength of 100 nm to 190 nm. The angle between the slow axis of the protective component and the slow axis of the λ / 4 layer is 30°~60°.

3. The optical laminate according to claim 1, further comprising a polarizing member disposed on the first principal surface side of the phase difference member. The angle between the slow axis of the protective component and the polarization axis of the polarization component is less than 15° or between 75° and 105°.

4. The optical laminate according to claim 1, wherein, The difference between the ellipticity of the 550nm wavelength light emitted from the second principal surface side of the phase difference member and the ellipticity of the 550nm wavelength light emitted from the circularly polarized light after the circularly polarized light passes through the protective member is less than 0.

02.

5. The optical laminate according to claim 4, wherein it satisfies at least one of (i) and (ii) below: (i) The difference between the ellipticity of the 450nm wavelength light emitted from the second principal surface side of the phase difference member and the ellipticity of the 450nm wavelength light emitted from the circularly polarized light after the circularly polarized light passes through the protective member is less than 0.

02. (ii) The difference between the ellipticity of the 650nm wavelength light emitted from the second principal surface side of the phase difference member and the ellipticity of the 650nm wavelength light emitted from the circularly polarized light after the circularly polarized light passes through the protective member is less than 0.

02.

6. The optical laminate according to claim 1, wherein, The protective component comprises a base material. The substrate comprises at least one resin selected from acrylic resins and cellulose triacetate resins.

7. The optical laminate according to claim 6, wherein, The protective member further includes an anti-reflective layer disposed on the opposite side of the substrate on the side where the phase difference member is disposed.

8. The optical laminate according to claim 1, wherein, The Re(550) of the protective component is greater than 0.5 nm.

9. The optical laminate according to claim 1, wherein, The phase difference component and the protective component are laminated together via an adhesive layer.

10. The optical laminate according to claim 1, used in a display system. The display system includes: A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member; A reflective polarizing element is disposed in front of the display element and reflects light emitted from the display element; A first lens portion is disposed in the optical path between the display element and the reflective polarizing member; A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member; A first phase difference component is disposed in the optical path between the display element and the half-reflector, and is capable of converting linearly polarized light into circularly polarized light or vice versa. as well as The second phase difference component is disposed in the optical path between the half-reflector and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa. The phase difference component is configured to function as either the first phase difference component or the second phase difference component.

11. A display system comprising: A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member; A reflective polarizing element is disposed in front of the display element and reflects light emitted from the display element; A first lens portion is disposed in the optical path between the display element and the reflective polarizing member; A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member; A first phase difference component is disposed in the optical path between the display element and the half-reflector, and is capable of converting linearly polarized light into circularly polarized light or vice versa. as well as The second phase difference component is disposed in the optical path between the half-reflector and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa. An optical laminate as described in claim 1 is disposed behind the semi-reflective mirror, such that the second principal surface of the phase difference member becomes the side of the semi-reflective mirror.

12. A display system comprising: A display element having a display surface from which light for displaying an image is emitted forward via a polarizing member; A reflective polarizing element is disposed in front of the display element and reflects light emitted from the display element; A first lens portion is disposed in the optical path between the display element and the reflective polarizing member; A semi-reflective mirror is disposed between the display element and the first lens portion, allowing light emitted from the display element to pass through and causing light that has been reflected by the reflective polarizing member to reflect towards the reflective polarizing member; A first phase difference component is disposed in the optical path between the display element and the half-reflector, and is capable of converting linearly polarized light into circularly polarized light or vice versa. as well as The second phase difference component is disposed in the optical path between the half-reflector and the reflective polarizing component, and is capable of converting linearly polarized light into circularly polarized light, or vice versa. An optical laminate as described in claim 1 is disposed in front of the semi-reflective mirror, such that the second principal surface of the phase difference member becomes the side of the semi-reflective mirror.

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