Display system and near-eye display device

Abstract

The present invention improves the efficiency with which light emitted from a self-emissive display device is utilized in a near-eye display device.　Provided is a display system included in a near-eye display device. The display system comprises: a self-emissive display element having a display surface that emits light representing an image; a lens capable of enlarging the image; an absorptive polarizing member disposed in an optical path between the self-emissive light-emitting element and the lens; and a phase difference member and a reflective polarizing member which are disposed in an optical path between the self-emissive light-emitting element and the absorptive polarizing member. The phase difference member is capable of converting linearly polarized light into circularly polarized light or converting circularly polarized light into linearly polarized light.

Description

Display system and near-eye display device

[0001] The present invention relates to a display system and a near-eye display device.

[0002] In a self-emitting type image display device typified by an electroluminescence (EL) display device (for example, an organic EL display device), in order to improve, for example, the performance of image display, generally, optical members such as a polarizing member and a retardation member are used (for example, refer to Patent Document 1).

[0003] By the way, in recent years, as a new application of an image display device, a near-eye display device has been proposed. For example, augmented reality (AR) technology has attracted attention, and AR devices (for example, AR glasses, head-mounted displays) used for AR have been proposed. Also, for example, a display-equipped goggle (VR goggle) for realizing virtual reality (VR) has been proposed.

[0004] Japanese Patent Application Laid-Open No. 2021-103286

[0005] In the above near-eye display device, the utilization efficiency of light emitted from the self-emitting display element mounted thereon tends to be low.

[0006] In view of the above, an object of the present invention is to improve the utilization efficiency of light emitted from a self-emitting display device in a near-eye display device.

[0007] 1. An embodiment of the present invention is a display system included in a near-eye display device, comprising: a self-emissive display element having a display surface that emits light representing an image; a lens capable of magnifying the image; an absorbing polarizing member disposed in the optical path between the self-emissive light-emitting element and the lens; and a phase difference member and a reflective polarizing member disposed in the optical path between the self-emissive light-emitting element and the absorbing polarizing member, wherein the phase difference member is a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. 2. In the display system described in 1 above, the proportion of the area on the display surface that is exposed to ambient light when a user wears the near-eye display device may be 50% or less. 3. In the display system described in 1 or 2 above, the display surface of the self-emissive display element may be arranged to overlap with the lens in a plan view. 4. In the display system described in any of 1 to 3 above, the absorbing polarizing member, the phase difference member, and the reflective polarizing member may be integrated via an adhesive layer. 5. 1. In the display system described in any of 1 to 4 above, the reflective polarizing member may be a reflective linear polarizing member, and the phase difference member, the reflective polarizing member, and the absorptive polarizing member may be arranged in the optical path between the self-emitting light-emitting element and the lens in the order from the self-emitting light-emitting element side. 6. In the display system described in any of 1 to 4 above, the reflective polarizing member may be a reflective circular polarizing member, and the reflective polarizing member, the phase difference member, and the absorptive polarizing member may be arranged in the optical path between the self-emitting light-emitting element and the lens in the order from the self-emitting light-emitting element side. 7. A near-eye display device according to an embodiment of the present invention includes the display system described in any of 1 to 6 above.

[0008] According to the display system of the embodiment of the present invention, the utilization efficiency of light emitted from a self-emissive display device can be improved in a near-eye display device.

[0009] This is a schematic diagram showing the general configuration of a display system according to the first embodiment of the present invention. This is a schematic diagram illustrating an example of how light emitted from a self-emissive display element propagates in a display system according to an embodiment of the present invention. This is a schematic diagram illustrating an example of how ambient light propagates in a display system according to an embodiment of the present invention. This is a schematic perspective view showing an example of a multilayer structure contained in a reflective linear polarizing film. This is a schematic diagram illustrating another example of how light emitted from a self-emissive display element propagates in a display system according to an embodiment of the present invention. This is a schematic diagram illustrating another example of how ambient light propagates in a display system according to an embodiment of the present invention. This is a schematic diagram showing the general configuration of a display system according to the second embodiment of the present invention. This is a graph showing the brightness measurement results of optical laminates of the examples and comparative examples.

[0010] Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to these embodiments. While the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the embodiments in order to clarify the explanation, these are merely examples and do not limit the interpretation of the present invention. Furthermore, in the drawings, the same or equivalent elements are denoted by the same reference numerals, and redundant explanations may be omitted.

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

[0012] Representative examples of near-eye display devices according to embodiments of the present invention include VR goggles and AR devices.

[0013] Figure 1 is a schematic diagram showing the general configuration of a display system according to the first embodiment of the present invention. The display system shown in Figure 1 can typically be included in VR goggles.

[0014] The display system 2 comprises a self-illuminating display element 10, an absorbing polarizing member 12, a reflecting part 14, a lens 16, a half mirror 18, a first phase difference member 20, and a second phase difference member 22. The reflecting part 14 includes a reflective polarizing member and is positioned in front of the self-illuminating display element 10 on the display surface 10a side (right side in Figure 1), and is capable of reflecting light emitted from the self-illuminating display element 10. The reflective polarizing member included in the reflecting part 14 may be a reflective linear polarizing member. The first phase difference member 20 and the second phase difference member 22 may each be phase difference members capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light.

[0015] The lens 16 is positioned in the optical path between the self-emissive display element 10 and the reflecting part 14, and may, for example, magnify the image displayed on the display surface 10a of the self-emissive display element 10. The display surface 10a of the self-emissive display element 10 may be positioned to overlap with the lens 16 in a plan view. The half mirror 18 is positioned between the self-emissive display element 10 and the lens 16. The absorbing polarizing member 12 is positioned in the optical path between the self-emissive display element 10 and the half mirror 18, the first phase difference member 20 is positioned in the optical path between the absorbing polarizing member 12 and the half mirror 18, and the second phase difference member 22 is positioned in the optical path between the half mirror 18 and the reflecting part 14. Although not shown, the display system 2 may also have a lens other than the lens 16. The other lens may, for example, be positioned in front of the reflecting part 14.

[0016] The self-emissive display element 10 is typically an organic EL display and has a display surface 10a for displaying an image. A lens array may be provided within the organic EL display. Light (natural light) emitted from the display surface 10a of the self-emissive display element 10 can be converted into first linearly polarized light by passing through the absorbing polarizing member 12.

[0017] The first phase difference member 20 can convert the first linearly polarized light incident on the first phase difference member 20 into the first circularly polarized light.

[0018] The half-mirror 18 transmits light emitted from the self-illuminating display element 10 and reflects the light reflected by the reflecting part 14 back towards the reflecting part 14. In Figure 1, the half-mirror 18 and the lens 16 are spaced apart, but the half-mirror 18 may be integrally provided with the lens 16.

[0019] The second phase difference member 22 can transmit light reflected by the reflective portion 14 and the half mirror 18 through the reflective portion 14, which includes a reflective polarizing member. In Figure 1, the second phase difference member 22 and the lens 16 are spaced apart, but the second phase difference member 22 may be integrally provided with the lens 16.

[0020] The first circularly polarized light emitted from the first phase difference member 20 passes through the half mirror 18 and the lens 16 and is converted into a second linearly polarized light by the second phase difference member 22. The second linearly polarized light emitted from the second phase difference member 22 is reflected toward the half mirror 18 without passing through the reflecting portion 14. At this time, the polarization direction of the second linearly polarized light incident on the reflective polarizing member included in the reflecting portion 14 may be in the same direction as the reflection axis of the reflective polarizing member. Therefore, the second linearly polarized light incident on the reflecting portion 14 can be reflected by the reflecting portion 14.

[0021] The second linearly polarized light reflected by the reflective section 14 is converted into a second circularly polarized light by the second phase difference member 22, and the second circularly polarized light emitted from the second phase difference member 22 passes through the lens 16 and is reflected by the half mirror 18. The circularly polarized light reflected by the half mirror 18 passes through the lens 16 and is converted into a third linearly polarized light by the second phase difference member 22. The third linearly polarized light is transmitted through the reflective section 14. At this time, the polarization direction of the third linearly polarized light incident on the reflective polarizing member included in the reflective section 14 may be in the same direction as the transmission axis of the reflective polarizing member. Therefore, the third linearly polarized light incident on the reflective section 14 can be transmitted through the reflective section 14. The light transmitted through the reflective section 14 is incident on the user's eye 3.

[0022] For example, the absorption axis of the absorbing polarizing member 12 and the reflection axis of the reflective polarizing member included in the reflection portion 14 may be arranged substantially parallel to each other, or substantially perpendicular to each other.

[0023] Although not shown in the figures, the reflective portion 14 may include an absorptive polarizing member positioned in front of the reflective polarizing member. In this case, the reflection axis of the reflective polarizing member and the absorption axis of the absorptive polarizing member may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member and the transmission axis of the absorptive polarizing member may be arranged substantially parallel to each other. In the reflective portion 14, the absorptive polarizing member may typically be provided integrally with the reflective polarizing member.

[0024] In the display system 2, a third phase difference member 30 and a reflective polarizing member 32 are provided between the self-emissive display element 10 and the absorptive polarizing member 12. The third phase difference member 30 may be a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. By providing the third phase difference member 30 and the reflective polarizing member 32 between the self-emissive display element 10 and the absorptive polarizing member 12, the light emitted from the self-emissive display element 10 can be effectively utilized, for example, contributing to an improvement in brightness. Light emitted from the display surface 10a of the self-emissive display element 10 passes through the absorptive polarizing member 12 via the third phase difference member 30 and the reflective polarizing member 32, and can be converted to linearly polarized light. At least a part of the member arranged behind the half mirror 18 (left side in Figure 1) may be integrally provided with the self-emissive display element 10. Specifically, at least a portion of the third phase difference member 30, the reflective polarizing member 32, the absorbing polarizing member 12, and the first phase difference member 20 may be integrally provided with the self-illuminating display element 10.

[0025] In the example shown in Figure 1, the third phase difference member 30, the reflective polarizing member 32, and the absorptive polarizing member 12 are arranged in this order from the self-illuminating display element 10 side toward the lens 16 side. In this case, the reflective polarizing member 32 may be a reflective linear polarizing member. The reflection axis of the reflective polarizing member (reflective linear polarizing member) 32 and the absorption axis of the absorptive polarizing member 12 may be arranged substantially parallel to each other, and the transmission axis of the reflective polarizing member (reflective linear polarizing member) 32 and the transmission axis of the absorptive polarizing member 12 may be arranged substantially parallel to each other.

[0026] If the third phase difference member 30 and the reflective polarizing member 32 are not provided, a portion (for example, half) of the light emitted from the self-emissive display element 10 may be absorbed by the absorptive polarizing member 12. In contrast, by providing the third phase difference member 30 and the reflective polarizing member (reflective linear polarizing member) 32 between the self-emissive display element 10 and the absorptive polarizing member 12, the light emitted from the self-emissive display element 10 can be effectively utilized. Specifically, as shown in Figure 2A, the light emitted from the self-emissive display element 10 (natural light) passes through the third phase difference member 30, and a portion of the light that has passed through the third phase difference member 30 passes through the reflective polarizing member 32, becomes linearly polarized, and can then pass through the absorptive polarizing member 12. A portion of the light that passes through the third phase difference member 30 is reflected by the reflective polarizing member 32. The light reflected by the reflective polarizing member 32 (linearly polarized) is converted to circularly polarized light by the third phase difference member 30, and then reflected by the display surface 10a of the self-emissive display element 10, and can be converted back to linearly polarized light by the third phase difference member 30. Subsequently, the linearly polarized light can pass through the reflective polarizing member 32 and can pass through the absorptive polarizing member 12. In this way, the light emitted from the self-emissive display element 10 can be effectively utilized.

[0027] On the other hand, by providing a third phase difference member 30 and a reflective polarizing member 32 between the self-emissive display element 10 and the absorptive polarizing member 12, the effect of preventing external light reflection may be sacrificed. For example, as shown in Figure 2B, light that passes through the absorptive polarizing member 12 from the external light incident into the display system 2 may pass through the reflective polarizing member 32, then pass through the third phase difference member 30 and be converted to circular polarization, and then be reflected by the display surface 10a of the self-emissive display element 10 and converted to linear polarization by the third phase difference member 30. After that, the light converted to linear polarization is reflected by the reflective polarizing member 32, passes through the third phase difference member 30 again and is converted to circular polarization, and then is reflected by the display surface 10a of the self-emissive display element 10 and converted to linear polarization by the third phase difference member 30. After that, the light converted to linear polarization may pass through the reflective polarizing member 32 and the absorptive polarizing member 12 and reach the user. However, when a user wears VR goggles, the display system 2 is surrounded by the housing (not shown) and the user, so it is unlikely that ambient light will enter the display system 2 (hit the display surface 10a) in the first place. Specifically, when a user wears VR goggles, the housing and the user can shield the display surface 10a from ambient light, and the proportion of the area on the display surface 10a that can be hit by ambient light may be 50% or less, preferably 30% or less, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 1% or less.

[0028] Even if ambient light is incident on the display surface 10a of the self-emissive display element 10 from the user side (right side in Figure 1), as shown by the dashed line in Figure 1, the ambient light incident on the user side is converted to linear polarization by the reflecting part 14, then converted to circular polarization by the second phase difference member 22, passes through the lens 16 and half mirror 18, is converted to linear polarization by the first phase difference member 20, and can be absorbed by the absorbing polarizing member 12. In VR goggles, it is preferable that the display surface 10a of the self-emissive display element 10 is covered by a housing (not shown) and a lens 16, so that only ambient light that has passed through the lens 16 can proceed toward the display surface 10a of the self-emissive display element 10. Note that a portion of the light emitted from the self-emissive display element 10 (first circular polarization) can be reflected back to the self-emissive display element 10 by the half mirror 18, as shown by the dashed line in Figure 1, but the light reflected by the half mirror 18 can be converted to linear polarization by the first phase difference member 20 and can be absorbed by the absorbing polarizing member 12.

[0029] The display system 2 may include other phase difference members. For example, a member that provides a phase difference in the thickness direction may be used as another phase difference member. The member that provides a phase difference in the thickness direction may be used in combination with a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. The member that provides a phase difference in the thickness direction may be, for example, a member whose refractive index characteristics exhibit the relationship nz > nx = ny (a so-called positive C plate), or a member whose refractive index characteristics exhibit the relationship nx = ny > nnz (a so-called negative C plate), or a combination thereof. Here, "nx = ny" includes not only the case where nx and ny are exactly equal, but also the case where nx and ny are substantially equal. The in-plane phase difference Re(550) of the member that provides a phase difference in the thickness direction is, for example, less than 10 nm.

[0030] Although not shown in the diagram, the integration of various optical components can typically be performed using any suitable adhesive layer. The adhesive layer may be formed from an adhesive or a tack. Specifically, the adhesive layer may be an adhesive layer or a tack layer. The thickness of the adhesive layer is, for example, 0.05 μm to 30 μm.

[0031] Although not shown in the figures, various optical components may be combined with functional layers having light-diffusing properties. In one embodiment, the adhesive layer may be a functional layer. Specifically, a diffusing adhesive layer having light-diffusing properties may be used to integrate the various optical components.

[0032] The above-mentioned absorption-type polarizing member typically includes a resin film containing a dichroic substance (sometimes referred to as an absorption-type polarizing film). The absorption-type polarizing member may, for example, include a protective layer for the absorption-type polarizing film.

[0033] The thickness of the absorption polarizing film is, for example, 1 μm or more and 20 μm or less, but may also be 2 μm or more and 15 μm or less, 12 μm or less, 10 μm or less, 8 μm or less, or 5 μm or less.

[0034] The above-mentioned absorption polarizing film may be made from a single layer of resin film, or it may be made using a laminate of two or more layers.

[0035] When manufactured from a single layer of resin film, an absorption polarizing film can be obtained by subjecting a hydrophilic polymer film, such as a polyvinyl alcohol (PVA) film, a partially formalized PVA film, or a partially saponified ethylene-vinyl acetate copolymer film, to dyeing treatment with a dichroic substance such as iodine or a dichroic dye, and stretching treatment. Among these, an absorption polarizing film obtained by dyeing a PVA film with iodine and uniaxially stretching it is preferred.

[0036] The above-mentioned iodine dyeing is carried out, for example, by immersing the PVA-based film in an iodine aqueous solution. The stretching ratio for the above-mentioned uniaxial stretching is preferably 3 to 7 times. Stretching may be performed after the dyeing treatment, or during the dyeing process. Alternatively, dyeing may be performed after stretching. If necessary, the PVA-based film may be subjected to swelling treatment, crosslinking treatment, washing treatment, drying treatment, etc.

[0037] When using the above-mentioned laminate of two or more layers, examples of laminates include a laminate of a resin substrate and a PVA-based resin layer (PVA-based resin film) laminated on the resin substrate, or a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate. An absorption polarizing film obtained using a laminate of a resin substrate and a PVA-based resin layer coated on the resin substrate can be produced, for example, by applying a PVA-based resin solution to a resin substrate, drying it to form a PVA-based resin layer on the resin substrate, and obtaining a laminate of a resin substrate and a PVA-based resin layer; or by stretching and dyeing the laminate to make the PVA-based resin layer an absorption polarizing film. In this embodiment, preferably, a polyvinyl alcohol-based resin layer containing a halogenated compound and a polyvinyl alcohol-based resin is formed on one side of the resin substrate. Stretching typically includes immersing the laminate in an aqueous boric acid solution and stretching it. Furthermore, the stretching may, if necessary, further include air stretching the laminate at a high temperature (e.g., 95°C or higher) before stretching in a boric acid aqueous solution. In addition, in this embodiment, preferably, the laminate is subjected to a drying shrinkage treatment in which it shrinks by 2% or more in the width direction by heating while being transported in the longitudinal direction. Typically, the manufacturing method of this embodiment includes applying an air auxiliary stretching treatment, a dyeing treatment, an underwater stretching treatment, and a drying shrinkage treatment to the laminate in this order. By introducing auxiliary stretching, it is possible to increase the crystallinity of PVA even when PVA is coated onto a thermoplastic resin substrate, making it possible to achieve high optical properties. At the same time, by increasing the orientation of PVA in advance, it is possible to prevent problems such as a decrease in the orientation of PVA or dissolution when immersed in water in the subsequent dyeing and stretching processes, making it possible to achieve high optical properties. Furthermore, when the PVA-based resin layer is immersed in a liquid, the disorder of the orientation of polyvinyl alcohol molecules and the decrease in orientation can be suppressed compared to when the PVA-based resin layer does not contain halides. This can improve the optical properties of absorption polarizing films obtained through processing steps that involve immersing the laminate in a liquid, such as dyeing and underwater stretching. Furthermore, the optical properties can be improved by shrinking the laminate in the width direction through a drying shrinkage treatment.The resulting resin substrate / absorbent polarizing film laminate may be used as is (i.e., the resin substrate may be used as a protective layer for the absorbent polarizing film), or an appropriate protective layer may be laminated on the peeled surface obtained by removing the resin substrate from the resin substrate / absorbent polarizing film laminate, or on the surface opposite to the peeled surface, depending on the purpose. Details of such a method for manufacturing an absorbent polarizing film are described, for example, in Japanese Patent Application Publication No. 2012-73580 and Japanese Patent No. 6470455. The entire contents of these publications are incorporated herein by reference.

[0038] The orthogonal transmittance (Tc) of the absorbing polarizing film (absorbing polarizing member) is preferably 0.5% or less, more preferably 0.1% or less, and even more preferably 0.05% or less. The single-layer transmittance (Ts) of the absorbing polarizing film (absorbing polarizing member) is, for example, 41.0% to 45.0%, and preferably 42.0% or more. The degree of polarization (P) of the absorbing polarizing film (absorbing polarizing member) is, for example, 99.0% to 99.997%, and preferably 99.9% or more.

[0039] The above-described reflective linear polarizing member transmits light polarized parallel to its transmission axis (typically linearly polarized light) while maintaining its polarization state, and reflects light in other polarization states (typically light polarized perpendicular to its transmission axis). The reflective linear polarizing member is typically composed of a multilayer film (sometimes referred to as a reflective linear polarizing film). In this case, the thickness of the reflective linear polarizing member is, for example, 10 μm to 150 μm, preferably 20 μm to 100 μm, and more preferably 30 μm to 60 μm.

[0040] Figure 3 is a schematic perspective view showing an example of a multilayer structure included in a reflective linear polarizing film. The multilayer structure 14a has alternating layers A having birefringence and layers B having substantially no birefringence. The total number of layers constituting the multilayer structure may be 50 to 1000. For example, the refractive index nx in the x-axis direction of layer A is greater than the refractive index ny in the y-axis direction, and the refractive index nx in the x-axis direction and the refractive index ny in the y-axis direction of layer B are substantially the same. The refractive index difference between layer A and layer B is large in the x-axis direction and substantially zero in the y-axis direction. As a result, the x-axis direction can be the reflection axis and the y-axis direction can be the transmission axis. The refractive index difference between layer A and layer B in the x-axis direction is preferably 0.2 to 0.3.

[0041] The above layer A is typically composed of a material that exhibits birefringence by stretching. Examples of such materials include naphthalenedicarboxylic acid polyester (e.g., polyethylene naphthalate), polycarbonate, and acrylic resins (e.g., polymethyl methacrylate). The above layer B is typically composed of a material that does not substantially exhibit birefringence even when stretched. Examples of such materials include copolyesters of naphthalenedicarboxylic acid and terephthalic acid. The above multilayer structure can be formed by combining coextrusion and stretching. For example, after extruding the material constituting layer A and the material constituting layer B, they are multilayered (e.g., using a multiplier). Then, the obtained multilayer laminate is stretched. The x-axis direction in the illustrated example may correspond to the stretching direction.

[0042] Examples of commercially available reflective linear polarizing films include products with the trade names "DBEF" and "APF" manufactured by 3M, and "APCF" manufactured by Nitto Denko Corporation.

[0043] The orthogonal transmittance (Tc) of a reflective linear polarizing member (reflective linear polarizing film) can be, for example, 0.001% to 3%. The single transmittance (Ts) of a reflective linear polarizing member (reflective linear polarizing film) is, for example, 43% to 49%, preferably 45% to 47%. The degree of polarization (P) of a reflective linear polarizing member (reflective linear polarizing film) can be, for example, 92% to 99.99%. [[ID=![CDATA

[10] ]]

[0044] As described above, each of the first retardation member 20, the second retardation member 22, and the third retardation member 30 (hereinafter, may be simply referred to as a retardation member) can be a retardation member that can convert linearly polarized light into circularly polarized light or circularly polarized light into linearly polarized light. The retardation member may be composed of a single layer or may have a laminated structure.

[0045] When the retardation member is composed of a single layer, typically, the retardation member can be a λ / 4 member. The in-plane retardation Re(550) of the λ / 4 member is, for example, 100 nm to 190 nm, may be 110 nm to 180 nm, may be 130 nm to 160 nm, or may be 135 nm to 155 nm.

[0046] The λ / 4 member preferably exhibits an inverse dispersion wavelength characteristic in which the retardation value increases according to the wavelength of the measurement light. Re(450) / Re(550) of the λ / 4 member is, for example, less than 1, may be 0.95 or less, and further may be less than 0.90, and even further may be 0.85 or less. Re(450) / Re(550) of the λ / 4 member is, for example, 0.75 or more.

[0047] In one embodiment, the λ / 4 member satisfies all of Re(400) / Re(550) < 0.85, Re(650) / Re(550) > 1.03, and Re(750) / Re(550) > 1.05. The λ / 4 member preferably satisfies at least one selected from 0.65 < Re(400) / Re(550) < 0.80 (preferably, 0.7 < Re(400) / Re(550) < 0.75), 1.0 < Re(650) / Re(550) < 1.25 (preferably, 1.05 < Re(650) / Re(550) < 1.20), and 1.05 < Re(750) / Re(550) < 1.40 (preferably, 1.08 < Re(750) / Re(550) < 1.36), more preferably satisfies at least two, and even more preferably satisfies all.

[0048] A λ / 4 member may, for example, exhibit a refractive index characteristic relating nx > ny ≥ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal, but also the case where they are substantially equal. Therefore, there may be cases where ny < nz. The Nz coefficient of the λ / 4 member is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3. The λ / 4 member may also, for example, exhibit a refractive index characteristic relating nx > nz > ny. The λ / 4 member may be composed of a so-called Z plate. The Nz coefficient of the λ / 4 member (Z plate) is, for example, 0.2 to 0.9, preferably 0.2 to 0.8, more preferably 0.3 to 0.7, even more preferably 0.4 to 0.6, and particularly preferably 0.45 to 0.55.

[0049] A λ / 4 member that can satisfy the above characteristics may be, for example, a stretched resin film or an oriented solidified layer of a liquid crystal compound.

[0050] Examples of resins included in the above-mentioned resin film include polycarbonate resins, polyester carbonate resins, polyester resins, polyvinyl acetal resins, polyarylate resins, cyclic olefin resins, cellulose resins, polyvinyl alcohol resins, polyamide resins, polyimide resins, polyether resins, polystyrene resins, and acrylic resins. These resins may be used individually or in combination (e.g., blended, copolymerized). When the λ / 4 component exhibits inverse dispersion wavelength characteristics, a resin film containing a polycarbonate resin or a polyester carbonate resin (hereinafter sometimes simply referred to as a polycarbonate resin) can be suitably used.

[0051] As the polycarbonate resin described above, any suitable polycarbonate resin can be used as long as the effects of the present invention are obtained. For example, the polycarbonate resin contains structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from at least one dihydroxy compound selected from the group consisting of alicyclic diols, alicyclic dimethanol, di, tri, or polyethylene glycol, and alkylene glycol or spiroglycol. Preferably, the polycarbonate resin contains structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, structural units derived from alicyclic dimethanol, and / or structural units derived from di, tri, or polyethylene glycol; more preferably, it contains structural units derived from fluorene-based dihydroxy compounds, structural units derived from isosorbide-based dihydroxy compounds, and structural units derived from di, tri, or polyethylene glycol. The polycarbonate resin may optionally contain structural units derived from other dihydroxy compounds. Further details regarding polycarbonate resins suitably used for λ / 4 members and methods for forming λ / 4 members are described, for example, in Japanese Patent Publication No. 2014-10291, Japanese Patent Publication No. 2014-26266, Japanese Patent Publication No. 2015-212816, Japanese Patent Publication No. 2015-212817, and Japanese Patent Publication No. 2015-212818, and the descriptions in these publications are incorporated herein by reference.

[0052] The orientation-solidified layer of the above-mentioned liquid crystal compound is a layer in which the liquid crystal compound is oriented in a predetermined direction within the layer, and this orientation state is fixed. Note that the term "orientation-solidified layer" is a concept that encompasses the orientation-cured layer obtained by curing liquid crystal monomers, as described later. In a λ / 4 member, typically, rod-shaped liquid crystal compounds are oriented in a state aligned along the slow axis direction of the λ / 4 member (homogenous orientation). Examples of rod-shaped liquid crystal compounds include liquid crystal polymers and liquid crystal monomers. Preferably, the liquid crystal compound is polymerizable. If the liquid crystal compound is polymerizable, the orientation state of the liquid crystal compound can be fixed by polymerizing it after orientation.

[0053] The oriented solidified layer of the above-mentioned liquid crystal compound (liquid crystal oriented solidified layer) can be formed by applying an orientation treatment to the surface of a predetermined substrate, coating the surface with a coating liquid containing the liquid crystal compound to orient the liquid crystal compound in the direction corresponding to the orientation treatment, and fixing the orientation state. Any appropriate orientation treatment can be used as the orientation treatment. Specifically, these include mechanical orientation treatment, physical orientation treatment, and chemical orientation treatment. Specific examples of mechanical orientation treatment include rubbing treatment and stretching treatment. Specific examples of physical orientation treatment include magnetic field orientation treatment and electric field orientation treatment. Specific examples of chemical orientation treatment include oblique deposition and photo-orientation treatment. Any appropriate conditions can be adopted for each orientation treatment depending on the purpose.

[0054] The orientation of liquid crystal compounds is achieved by treating them at a temperature that exhibits the liquid crystal phase, depending on the type of liquid crystal compound. This temperature treatment causes the liquid crystal compound to enter a liquid crystal state, and it then orients according to the orientation treatment direction on the substrate surface.

[0055] In one embodiment, the orientation state is fixed by cooling the liquid crystal compound oriented as described above. If the liquid crystal compound is polymerizable or crosslinkable, the orientation state is fixed by subjecting the liquid crystal compound oriented as described above to a polymerization treatment or a crosslinking treatment.

[0056] As the above-mentioned liquid crystal compound, any suitable liquid crystal polymer and / or liquid crystal monomer can be used. The liquid crystal polymer and liquid crystal monomer may be used individually or in combination. Specific examples of liquid crystal compounds and methods for producing liquid crystal alignment solidified layers are described, for example, in Japanese Patent Publication No. 2006-163343, Japanese Patent Publication No. 2006-178389, and International Publication No. 2018 / 123551. The descriptions in these publications are incorporated herein by reference.

[0057] The thickness of the λ / 4 member, which is composed of a stretched resin film, is, for example, 10 μm to 100 μm, preferably 10 μm to 70 μm, more preferably 10 μm to 60 μm, and even more preferably 20 μm to 50 μm. The thickness of the λ / 4 member, which is composed of a liquid crystal alignment solidification layer, is, for example, 1 μm to 10 μm, preferably 1 μm to 8 μm, more preferably 1 μm to 6 μm, and even more preferably 1 μm to 4 μm.

[0058] The angle between the absorption axis of the absorption-type polarizing member 12 and the slow-phase axis of the first phase difference member 20, which is a λ / 4 member, is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The angle between the absorption axis of the absorption-type polarizing member 12 and the slow-phase axis of the second phase difference member 22, which is a λ / 4 member, is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°. The angle between the absorption axis of the absorption-type polarizing member 12 and the slow-phase axis of the third phase difference member 30, which is a λ / 4 member, is, for example, 40° to 50°, may be 42° to 48°, or may be about 45°.

[0059] When the phase difference member has a laminated structure, typically the phase difference member has a laminated structure including a λ / 2 layer and a λ / 4 layer.

[0060] The in-plane phase difference Re(550) of the λ / 2 layer is, for example, 200 nm to 330 nm, but may also be 230 nm to 330 nm, 230 nm to 290 nm, or 250 nm to 280 nm.

[0061] The in-plane phase difference Re(550) of the λ / 4 layer is, for example, 100 nm to 200 nm, but may also be 110 nm to 180 nm, 130 nm to 160 nm, or 135 nm to 155 nm.

[0062] Each of the λ / 2 layer and λ / 4 layer (hereinafter sometimes simply referred to as the layer included in the laminated structure) preferably exhibits inverse dispersion wavelength characteristics in which the phase difference value increases with the wavelength of the measured light. The Re(450) / Re(550) of the layer included in the laminated structure is, for example, 0.75 or more and less than 1, and may be 0.8 or more and 0.95 or less.

[0063] The layers included in the laminated structure may exhibit flat wavelength dispersion characteristics in which the phase difference value hardly changes with respect to the wavelength of the measured light. In this case, the Re(450) / Re(550) ratio of the layers included in the laminated structure may be, for example, 0.99 to 1.03, and the Re(650) / Re(550) ratio may be, for example, 0.98 to 1.02.

[0064] The layers included in the laminated structure may, for example, exhibit a refractive index characteristic relating nx > ny ≥ nz. Here, "ny = nz" includes not only the case where ny and nz are exactly equal, but also the case where they are substantially equal. Therefore, there may be cases where ny < nz. The Nz coefficient of the layers included in the laminated structure is preferably 0.9 to 3, more preferably 0.9 to 2.5, even more preferably 0.9 to 1.5, and particularly preferably 0.9 to 1.3. The layers included in the laminated structure may also, for example, exhibit a refractive index characteristic relating nx > nz > ny. The layers included in the laminated structure may be composed of so-called Z plates. The Nz coefficient of the layers included in the laminated structure (Z plates) is, for example, 0.2 to 0.9, preferably 0.2 to 0.8, more preferably 0.3 to 0.7, even more preferably 0.4 to 0.6, and particularly preferably 0.45 to 0.55.

[0065] The layers included in the laminated structure are formed from any suitable material that can satisfy the above characteristics. The layers included in the laminated structure may be, for example, a stretched resin film or an oriented solidified layer of a liquid crystal compound. Details of the stretched resin film and the oriented solidified layer of a liquid crystal compound are as described above. When the layers included in the laminated structure have flat wavelength dispersion characteristics, cycloolefin resins, particularly norbornene resins, can be preferably used as the forming material.

[0066] Norbornene-based resins are resins polymerized using norbornene-based monomers as polymerization units. Examples of norbornene-based monomers include norbornene and its alkyl and / or alkylidene-substituted derivatives, such as 5-methyl-2-norbornene, 5-dimethyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-ethylidene-2-norbornene, etc., and their halogen- and other polar group-substituted derivatives; dicyclopentadiene, 2,3-dihydrodicyclopentadiene, etc. Dimethanooctahydronaphthalene, its alkyl and / or alkylidene substituted derivatives, and polar group substituted derivatives such as halogens, for example, 6-methyl-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethyl-1,4:5,8-dimethano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, 6-ethylidene-1,4:5,8-dimethano-1,4,4a,5,6 7,8,8a-Octahydronaphthalene, 6-Chloro-1,4:5,8-Dimethano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Cyano-1,4:5,8-Dimethano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Pyridyl-1,4:5,8-Dimethano-1,4,4a,5,6,7,8,8a-Octahydronaphthalene, 6-Methoxycarbonyl-1,4:5,8-Dimethano Examples include tano-1,4,4a,5,6,7,8,8a-octahydronaphthalene, and tripers to tetramers of cyclopentadiene, such as 4,9:5,8-dimethano-3a,4,4a,5,8,8a,9,9a-octahydro-1H-benzoindene, 4,11:5,10:6,9-trimethano-3a,4,4a,5,5a,6,9,9a,10,10a,11,11a-dodecahydro-1H-cyclopentaanthracene. The norbornene-based resin may also be a copolymer of a norbornene-based monomer and another monomer.

[0067] The above description of the λ / 4 member can be applied to the thickness of the λ / 4 layer. The thickness of the λ / 2 layer, which is composed of a stretched resin film, is, for example, 20 μm to 200 μm, preferably 20 μm to 140 μm, more preferably 20 μm to 120 μm, and even more preferably 40 μm to 100 μm. The thickness of the λ / 2 layer, which is composed of a liquid crystal alignment solidification layer, is, for example, 2 μm to 20 μm, preferably 2 μm to 16 μm, more preferably 2 μm to 12 μm, and even more preferably 2 μm to 8 μm. The same description as above for the λ / 2 layer can be applied to the details of the forming material and thickness of the λ / 2 member, which exhibits the relationship nx > ny ≥ nz in terms of refractive index characteristics.

[0068] In the phase difference member, the angle between the slow axis of the λ / 2 layer and the slow axis of the λ / 4 layer is preferably 50° to 70°, more preferably 55° to 65°, even more preferably 57° to 63°, and particularly preferably about 60°. In one embodiment, the angle between the absorption axis of the absorption polarizing member 12 and the slow axis of the λ / 2 layer is preferably 5° to 35°, more preferably 10° to 20°, even more preferably 12° to 18°, and particularly preferably about 15°. The angle between the absorption axis of the absorption polarizing member 12 and the slow axis of the λ / 4 layer is preferably 55° to 85°, more preferably 70° to 80°, even more preferably 72° to 78°, and particularly preferably about 75°. In another embodiment, the angle between the absorption axis of the absorption polarizing member 12 and the slow axis of the λ / 4 layer is preferably 5° to 35°, more preferably 10° to 20°, even more preferably 12° to 18°, and particularly preferably about 15°. The angle between the absorption axis of the absorption polarizing member 12 and the slow axis of the λ / 2 layer is preferably 55° to 85°, more preferably 70° to 80°, even more preferably 72° to 78°, and particularly preferably about 75°.

[0069] The first phase difference member 20, the second phase difference member 22, and the third phase difference member 30 may be members with substantially the same configuration (forming material, thickness, optical properties, etc.) or they may be members with different configurations. For example, from the viewpoint of manufacturing efficiency, the first phase difference member 20, the second phase difference member 22, and the third phase difference member 30 may have substantially the same configuration.

[0070] Unlike the example shown in Figure 1, the reflective polarizing member 32, the third phase difference member 30, and the absorbing polarizing member 12 may be arranged in this order from the self-emissive display element 10 side toward the lens 16 side. In this case, the reflective polarizing member 32 may be a reflective circular polarizing member. As described above, if the third phase difference member 30 and the reflective polarizing member 32 are not provided, a portion (for example, half) of the light emitted from the self-emissive display element 10 may be absorbed by the absorbing polarizing member 12. In contrast, by providing the reflective polarizing member (reflective circular polarizing member) 32 and the third phase difference member 30 between the self-emissive display element 10 and the absorbing polarizing member 12, as shown in Figure 4A, the light emitted from the self-emissive display element 10 that passes through the reflective polarizing member 32 may be right-circularly polarized, and the light reflected by the reflective polarizing member 32 may be left-circularly polarized. The right-circularly polarized light can be converted to linearly polarized light by the third phase difference member 30 and then pass through the absorbing polarizing member 12. Left-circularly polarized light can be reflected by the display surface 10a of the self-emissive display element 10 and then pass through the reflective polarizing member 32 and the absorbing polarizing member 12. In this way, the light emitted from the self-emissive display element 10 can be effectively utilized.

[0071] On the other hand, as described above, by providing a third phase difference member 30 and a reflective polarizing member 32 between the self-emissive display element 10 and the absorptive polarizing member 12, the effect of preventing external light reflection may be sacrificed. For example, as shown in Figure 4B, the light that passes through the absorptive polarizing member 12 from the external light incident into the display system 2 is converted into circular polarization by the third phase difference member 30, then can pass through the reflective polarizing member 32, be reflected by the display surface 10a of the self-emissive display element 10, and be reflected by the reflective polarizing member 32. Subsequently, the light reflected by the display surface 10a of the self-emissive display element 10 can pass through the reflective polarizing member 32, pass through the absorptive polarizing member 12, and reach the user. However, as described above, it is unlikely that external light will normally be incident into the display system 2 when a user is wearing VR goggles.

[0072] The above-described reflective circular polarizing member can transmit right-circularly polarized or left-circularly polarized light while maintaining its polarization state, and can reflect circularly polarized light whose rotation direction is opposite to that of the transmitted circularly polarized light. Typically, the reflective circular polarizing member can be composed of an orientation solidified layer of cholesterically oriented liquid crystal compound (cholesteric liquid crystal layer). The cholesteric liquid crystal layer may have a helical structure in which liquid crystal compounds are spirally spiraled and stacked, and when one pitch is defined as one rotation (360° rotation) of the liquid crystal compound spiraling and stacked, the layer may have a structure in which multiple pitches of spirally spiraling liquid crystal compound are stacked.

[0073] The cholesteric liquid crystal layer described above can reflect right-circularly polarized or left-circularly polarized light in a specific wavelength range and transmit other light, depending on the length of the helical pitch, the direction of spiral rotation (sense) of the liquid crystal compound, etc. Therefore, in order to reflect a wavelength range that covers the entire visible range (for example, the range of 410 nm to 780 nm), the reflective circular polarizing member may include, for example, multiple cholesteric liquid crystal layers that can reflect different wavelength ranges. For example, the reflective circular polarizing member may include a cholesteric liquid crystal layer that can mainly reflect red light, a cholesteric liquid crystal layer that can mainly reflect green light, and a cholesteric liquid crystal layer that can mainly reflect blue light.

[0074] Figure 5 is a schematic diagram showing the general configuration of a display system according to a second embodiment of the present invention. The display system shown in Figure 5 may typically be included in an AR device and may be a so-called birdbath type.

[0075] The display system 200 includes a self-illuminating display element 10 for displaying an image, an absorbing polarizing member 12, a reflecting part 14, a lens 16, a half mirror 18, a first phase difference member 20, a second phase difference member 22, and a circular polarizing member 40 that can convert light received from an external object into circularly polarized light.

[0076] The reflective portion 14 is positioned between the circularly polarizing member 40 and the user 3. The reflective portion 14 is also positioned between the self-illuminating display element 10 and the user 3, and its main surface 14b is positioned obliquely to the display surface 10a of the self-illuminating display element 10. Specifically, the angle θ between the display surface 10a of the self-illuminating display element 10 and the main surface 14b of the reflective portion 14 is, for example, 40° to 50°, may be 42° to 48°, or may be approximately 45°.

[0077] The lens 16 is positioned in the optical path between the self-emissive display element 10 and the reflecting part 14, and may, for example, magnify the image displayed on the display surface 10a of the self-emissive display element 10. The display surface 10a of the self-emissive display element 10 may be positioned to overlap with the lens 16 in a plan view. The half mirror 18 is positioned in the optical path between the circular polarizing member 40 and the reflecting part 14. The absorbing polarizing member 12 is positioned in the optical path between the self-emissive display element 10 and the lens 16, and the first phase difference member 20 is positioned in the optical path between the absorbing polarizing member 12 and the lens 16. The second phase difference member 22 is positioned in the optical path between the half mirror 18 and the reflecting part 14, and is positioned in the optical path between the circular polarizing member 40 and the reflecting part 14. The reflecting part 14 includes a reflective polarizing member and can reflect light emitted from the self-emissive display element 10 toward the half mirror 18. The reflective polarizing member included in the reflecting part 14 may be a reflective linear polarizing member.

[0078] Light (natural light) emitted from the display surface 10a of the self-illuminating display element 10 can be converted into a fourth linearly polarized light by passing through the absorbing polarizing member 12. The first phase difference member 20 can convert the fourth linearly polarized light incident on the first phase difference member 20 into a third circularly polarized light. The half mirror 18 can reflect the light reflected by the reflecting part 14 back towards the reflecting part 14.

[0079] The second phase difference member 22 can transmit light reflected by the reflective portion 14 and the half mirror 18 through the reflective portion 14, which includes a reflective polarizing member. In Figure 5, the second phase difference member 22 is integrally provided with the reflective portion 14, but they may be arranged at a distance from each other.

[0080] The third circularly polarized light emitted from the first phase difference member 20 passes through the lens 16 and is converted into a fifth linearly polarized light by the second phase difference member 22. The fifth linearly polarized light emitted from the second phase difference member 22 is reflected toward the half mirror 18 without passing through the reflecting part 14. At this time, the polarization direction of the fifth linearly polarized light incident on the reflective polarizing member included in the reflecting part 14 may be in the same direction as the reflection axis of the reflective polarizing member. Therefore, the fifth linearly polarized light incident on the reflecting part 14 can be reflected by the reflecting part 14.

[0081] The fifth linearly polarized light reflected by the reflective section 14 is converted to the fourth circularly polarized light by the second phase difference member 22, and the fourth circularly polarized light emitted from the second phase difference member 22 is reflected by the half mirror 18. The circularly polarized light reflected by the half mirror 18 is converted to the sixth linearly polarized light by the second phase difference member 22. The sixth linearly polarized light is transmitted through the reflective section 14. At this time, the polarization direction of the sixth linearly polarized light incident on the reflective polarizing member included in the reflective section 14 may be in the same direction as the transmission axis of the reflective polarizing member. Therefore, the sixth linearly polarized light incident on the reflective section 14 can be transmitted through the reflective section 14. The light transmitted through the reflective section 14 is incident on the user's eye 3.

[0082] For example, the absorption axis of the absorbing polarizing member 12 and the reflection axis of the reflective polarizing member included in the reflection portion 14 may be arranged substantially parallel to each other or substantially orthogonal to each other when viewed from a direction perpendicular to the display surface 10a of the self-luminous display element 10.

[0083] In the display system 200, a third phase difference member 30 and a reflective polarizing member 32 are provided between the self-emissive display element 10 and the absorptive polarizing member 12. By providing the third phase difference member 30 and the reflective polarizing member 32 between the self-emissive display element 10 and the absorptive polarizing member 12, the light emitted from the self-emissive display element 10 can be effectively utilized, which can contribute to, for example, improving brightness. The third phase difference member 30 may be a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. Light emitted from the display surface 10a of the self-emissive display element 10 can pass through the absorptive polarizing member 12 via the third phase difference member 30 and the reflective polarizing member 32, and be converted to linearly polarized light. At least a part of the third phase difference member 30, the reflective polarizing member 32, the absorptive polarizing member 12, the first phase difference member 20, and the lens 16 may be integrally provided with the self-emissive display element 10.

[0084] Light received from an external object located in front of user 3 is converted into circularly polarized light by the circularly polarizing member 40, passes through the half mirror 18, is converted into linearly polarized light by the second phase difference member 22, and can pass through the reflecting part 14 and enter the user's eye 3. The circularly polarizing member 40 is typically a laminate of an absorbing polarizing member 42 and a fourth phase difference member 44. The fourth phase difference member 44 is a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light. For example, the absorption axis of the absorbing polarizing member 42 included in the circularly polarizing member 40 and the reflection axis of the reflective polarizing member included in the reflecting part 14 may be arranged substantially parallel to each other or substantially orthogonal to each other when viewed from a direction perpendicular to the main surface 40a of the circularly polarizing member 40.

[0085] Although not shown in the illustration, unlike the example shown in Figure 5, the reflective polarizing member 32, the third phase difference member 30, and the absorbing polarizing member 12 may be arranged in this order from the self-illuminating display element 10 side toward the lens 16 side. In this case, the reflective polarizing member 32 may be a reflective circular polarizing member.

[0086] In a display system included in an AR device, the user can simultaneously perceive the light emitted from the self-emissive display element 10 and the light received from an external object. Therefore, by providing the third phase difference member 30 and the reflective polarizing member 32, a significant improvement in visibility can be obtained by increasing the brightness of the light emitted from the self-emissive display element 10.

[0087] On the other hand, as described above, by providing a third phase difference member 30 and a reflective polarizing member 32 between the self-emissive display element 10 and the absorbing polarizing member 12, the effect of preventing external light reflection may be sacrificed. However, when a user wears the AR device, the display surface 10a of the self-emissive display element 10 can be positioned to face downwards, and since the self-emissive display element 10 is covered by a cover member in the AR device, it is unlikely that external light will strike the display surface 10a in the first place. Specifically, when a user wears the AR device, the cover member and the user can shield the display surface 10a from external light, and the proportion of the area on the display surface 10a that can be struck by external light may be 50% or less, preferably 30% or less, more preferably 10% or less, even more preferably 5% or less, and particularly preferably 1% or less. Furthermore, when the AR device is not worn by a user, for example, when no image is displayed on the display surface 10a and it is in a black display state, the effect of preventing external light reflection on the display surface 10a is usually not required. In the AR device, it is preferable that the display surface 10a of the self-emissive display element 10 is covered by a cover member (not shown) and a lens 16, so that only ambient light that has passed through the lens 16 can proceed toward the display surface 10a of the self-emissive display element 10.

[0088] In one embodiment, an optical component set having optical components that can be provided in the display system described above may be provided. For example, the absorbing polarizing component 12, the third phase difference component 30, and the reflective polarizing component 32 may be integrated via an adhesive layer. Specifically, the absorbing polarizing component 12, the third phase difference component 30, and the reflective polarizing component 32 may constitute an optical laminate. The integration of multiple optical components can typically be achieved by laminating each optical component via any suitable adhesive layer.

[0089] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples. The methods for measuring thickness, phase difference value, and polarization characteristics are as follows.

[0090] (1) Thickness Thickness of 10 μm or less was measured using a scanning electron microscope (JEOL Ltd., product name "JSM-7100F"). Thickness exceeding 10 μm was measured using a digital micrometer (Anritsu Corporation, product name "KC-351C"). (2) Phase difference value Phase difference / elliptic polarization measuring device (Oji Instruments Co., Ltd., product names "KOBRA-HBR" and "KOBRA-HBPR") was used to measure the phase difference value at a predetermined wavelength at 23°C. (3) Transmittance and degree of polarization of polarizing film Single unit transmittance Ts, parallel transmittance Tp, and orthogonal transmittance Tc of polarizing film were measured using a spectrophotometer (Otsuka Electronics Co., Ltd., "LPF-200"). These Ts, Tp, and Tc are Y values ​​measured using a 2-degree field of view (C light source) according to JIS Z8701 and corrected for luminous sensitivity. The degree of polarization of the polarizing film was determined from the obtained Tp and Tc values ​​using the following formula: Degree of polarization (%) = {(Tp - Tc) / (Tp + Tc)} １／２ ×100

[0091] [Manufacturing Example 1: Fabrication of Absorbing Polarizing Film] An amorphous isophthalic copolymer polyethylene terephthalate film (thickness: 100 μm) with a long length and a Tg of approximately 75°C was used as the thermoplastic resin substrate, and one side of the resin substrate was subjected to corona treatment. 100 parts by weight of a PVA-based 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 "Gosenex Z410") in a 9:1 ratio, was mixed with 13 parts by weight of potassium iodide, and this mixture was dissolved in water to prepare a PVA aqueous solution (coating solution). The above PVA aqueous solution was applied to the corona-treated surface of the resin substrate and dried at 60°C to form a PVA-based resin layer with a thickness of 13 μm, thereby producing a laminate. The obtained laminate was uniaxially stretched 2.4 times in the longitudinal direction (longitudinal direction) in an oven at 130°C (air-assisted stretching treatment). Next, the laminate was immersed for 30 seconds in an insolubilization bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water) (insolubilization treatment). Next, the laminate was immersed for 60 seconds in a staining bath at a liquid temperature of 30°C (a iodine aqueous solution obtained by mixing iodine and potassium iodide in a weight ratio of 1:7 with 100 parts by weight of water), while adjusting the concentration so that the transmittance (Ts) of the final absorption polarizing film would be the desired value (staining treatment). Next, the laminate was immersed for 30 seconds in a crosslinking bath at a liquid temperature of 40°C (a boric acid aqueous solution obtained by mixing 3 parts by weight of potassium iodide and 5 parts by weight of boric acid with 100 parts by weight of water) (crosslinking treatment). Subsequently, the laminate was uniaxially stretched in the longitudinal direction (longitudinal direction) to a total stretch ratio of 5.5 times while immersed in a boric acid aqueous solution (boric acid concentration 4% by weight, potassium iodide concentration 5% by weight) at a liquid temperature of 70°C (water stretching treatment). After that, the laminate was immersed in a washing bath at a liquid temperature of 20°C (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) (washing treatment). After that, the laminate was dried in an oven maintained at approximately 90°C while being brought into contact with a heated SUS roll whose surface temperature was maintained at approximately 75°C (drying shrinkage treatment). The shrinkage rate in the width direction of the laminate due to the drying shrinkage treatment was 5.2%. In this way, an absorption-type polarizing film with a thickness of approximately 5 μm was formed on the resin substrate.A cycloolefin resin film (thickness: 25 μm) was bonded to the surface of the obtained absorbing polarizing film (the side opposite to the resin substrate) via an ultraviolet-curing adhesive. Specifically, the curing adhesive was applied to a total thickness of approximately 1 μm and bonded using a roll press. Then, UV light was irradiated from the cycloolefin resin film side to cure the adhesive. Next, the resin substrate was peeled off. This yielded an absorbing polarizing film having a cycloolefin resin film / absorbing polarizing film structure. The transmittance (Ts) of the absorbing polarizing film was 43.4%, and the degree of polarization was 99.993%.

[0092] [Production Example 2: Preparation of Phase Difference Film] A batch polymerization apparatus consisting of two vertical reactors equipped with stirring blades and reflux condensers controlled to 100°C was used to prepare the following: 29.60 parts by weight (0.046 mol) of bis[9-(2-phenoxycarbonylethyl)fluoren-9-yl]methane, 29.21 parts by weight (0.200 mol) of isosorbide (ISB), 42.28 parts by weight (0.139 mol) of spiroglycol (SPG), 63.77 parts by weight (0.298 mol) of diphenyl carbonate (DPC), and 1.19 × 10⁻¹⁶ of calcium acetate monohydrate as a catalyst. －２ Part by weight (6.78 x 10 －５A mol of phenol was added. After purging the reactor with reduced pressure using nitrogen, the reactor was heated with a heat transfer medium, and stirring was started when the internal temperature reached 100°C. Forty minutes after the start of heating, the internal temperature was raised to 220°C, and while controlling the pressure to maintain this temperature, the pressure was reduced to 13.3 kPa 90 minutes after reaching 220°C. The phenol vapor produced as a by-product of the polymerization reaction was led to a reflux condenser at 100°C, and the monomer components contained in small amounts in the phenol vapor were returned to the reactor. The uncondensed phenol vapor was led to a condenser at 45°C and recovered. Nitrogen was introduced into the first reactor to restore the pressure to atmospheric pressure, and then the oligomerized reaction solution in the first reactor was transferred to the second reactor. Next, heating and depressurization in the second reactor were started, and the internal temperature reached 240°C and the pressure 0.2 kPa in 50 minutes. Polymerization was then allowed to proceed until the predetermined stirring power was reached. When the predetermined power was reached, nitrogen was introduced into the reactor to restore pressure, and the resulting polyester carbonate resin was extruded into water. The strands were then cut to obtain pellets. The obtained polyester carbonate resin (pellets) was vacuum-dried at 80°C for 5 hours. A long resin film with a thickness of 130 μm was then produced using a film-making apparatus equipped with a single-screw extruder (manufactured by Toshiba Machine Co., Ltd., cylinder setting temperature: 250°C), a T-die (width 200 mm, setting temperature: 250°C), a chill roll (setting temperature: 120-130°C), and a winding machine. The obtained long resin film was stretched in the width direction at a stretching temperature of 140°C and a stretching ratio of 2.7 times. In this way, a phase difference film with a thickness of 47 μm, a Re(590) of 140 nm, and an Nz coefficient (Rth(590) / Re(590)) of 1.2 was obtained. The Re(450) / Re(550) ratio of the obtained phase difference film was 0.859.

[0093] [Manufacturing Example 3: Fabrication of Reflective Circularly Polarized Light Member] A polyvinyl alcohol layer with a thickness of 0.1 μm was formed on a triacetylcellulose film, and this polyvinyl alcohol layer was subjected to a rubbing treatment. Subsequently, a cholesteric liquid crystal layer capable of separating circularly polarized light in the wavelength range of 410 nm to 780 nm was formed on the polyvinyl alcohol layer to obtain a reflective circularly polarized light member. The cholesteric liquid crystal layer was formed by multilayer coating. The thickness of the cholesteric liquid crystal layer was 6 μm.

[0094] [Example 1] "APCFG5" manufactured by Nitto Denko Corporation was prepared as a reflective linear polarizing member (reflective linear polarizing film). The transmittance (Ts) of this reflective linear polarizing film was 47.0%, and the degree of polarization was 93.1%. An absorptive polarizing film was bonded to one side of the reflective linear polarizing film via an adhesive layer with a thickness of 5 μm, and a phase difference film was bonded to the other side of the reflective linear polarizing film via an adhesive layer with a thickness of 5 μm to obtain an optical laminate. At this time, the absorptive polarizing film of the absorptive polarizing film was bonded so that it was located on the side of the reflective linear polarizing film. Furthermore, the reflective axis of the reflective linear polarizing film and the absorptive polarizing film were bonded so that they were parallel to each other. Furthermore, the reflective axis of the reflective linear polarizing film and the slow phase axis of the phase difference film were bonded so that they formed a 45° angle.

[0095] [Example 2] The phase difference film was bonded to the cholesteric liquid crystal layer side of the reflective circular polarizing member via a 5 μm thick adhesive layer, and then the absorbing polarizing film was bonded to the phase difference film side via a 5 μm thick adhesive layer to obtain an optical laminate. At this time, the absorbing polarizing film of the absorbing polarizing film was bonded so that it was positioned on the phase difference film side. Furthermore, the absorbing axis of the absorbing polarizing film and the slow axis of the phase difference film were bonded so that they formed a 45° angle.

[0096] [Comparative Example 1] An optical laminate was obtained by laminating an absorption polarizing film to the above phase difference film via an adhesive layer with a thickness of 5 μm. At this time, the absorption polarizing film of the absorption polarizing film was positioned on the phase difference film side. Furthermore, the lamination was performed so that the absorption axis of the absorption polarizing film and the slow phase axis of the phase difference film formed an angle of 45°.

[0097] The following evaluations were performed on the obtained optical laminate.

[0098] <Evaluation 1> The circular polarizer mounted on the display surface side of an organic EL display device (Samsung, product number "Galaxy A41") was removed, and the resulting optical laminate was placed on the display surface with its absorbing polarizing film facing upwards, and the display was set to white. Then, in this state, the brightness was measured using a viewing angle characteristic evaluation device (ELDIM, product name "EZ-Contrast") at an azimuth angle of 0° and an extreme angle from 0° to 88°. The measurement results are shown in Figure 6.

[0099] <Evaluation 2> The circular polarizer mounted on the display surface side of an organic EL display device (Samsung, product number "Galaxy A41") was removed, and the obtained optical laminate was placed on the display surface (organic EL panel) with its absorption polarizing film facing upwards, and the display was set to black. In this state, the SCI reflectance (Y value, reflectance 1) was measured using a spectrophotometer (Konica Minolta Japan, product name "CM-26d") with a D65 light source. The phase difference film was then bonded to the absorption polarizing film side of the obtained optical laminate via a 5 μm thick adhesive layer. Then, as shown in Table 1, optical component A, obtained by laminating the phase difference film to a glass plate with a half-mirror attached via a 5 μm thick adhesive layer, and optical component B, obtained by laminating the absorption-type polarizing film to a glass plate via a 5 μm thick adhesive layer, and further laminating the reflective-type linear polarizing film via a 5 μm thick adhesive layer, were placed on an optical laminate. The SCI reflectance (Y value, reflectance 2) was measured using a D65 light source with a spectrophotometer (Konica Minolta Japan, product name "CM-26d"). The angles shown in Table 1 are the angles made by the absorption axis, reflection axis, or slow-phase axis of each film with respect to the absorption axis of the absorption-type polarizing film (absorption-type polarizing film) contained in the optical laminate. The measurement results are summarized in Table 2.

[0100]

[0101]

[0102] The present invention is not limited to the embodiments described above, and various modifications are possible. For example, the configurations shown in the embodiments above can be replaced with configurations that are substantially the same, configurations that produce the same effects, or configurations that can achieve the same purpose.

[0103] The display system according to an embodiment of the present invention can be used, for example, in near-eye display devices such as VR goggles and AR devices.

[0104] 2 Display system, 3 User's eye (user), 10 Display element, 10a Display surface, 12 Absorbing polarizing member, 14 Reflecting part, 16 Lens, 18 Half mirror, 20 First phase difference member, 22 Second phase difference member, 30 Third phase difference member, 32 Reflecting polarizing member, 40 Circular polarizing member, 200 Display system.

Claims

1. A display system included in a near-eye display device, comprising: a self-emissive display element having a display surface that emits light representing an image; a lens capable of magnifying the image; an absorbing polarizing member disposed in the optical path between the self-emissive light-emitting element and the lens; and a phase difference member and a reflective polarizing member disposed in the optical path between the self-emissive light-emitting element and the absorbing polarizing member, wherein the phase difference member is a phase difference member capable of converting linearly polarized light to circularly polarized light, or circularly polarized light to linearly polarized light.

2. The display system according to claim 1, wherein the area of ​​the display surface exposed to ambient light when the user wears the near-eye display device is 50% or less.

3. The display system according to claim 1, wherein the display surface of the self-illuminating display element is arranged to overlap with the lens in a plan view.

4. The display system according to claim 1, wherein the absorbing polarizing member, the phase difference member, and the reflective polarizing member are integrated via an adhesive layer.

5. The display system according to claim 1, wherein the reflective polarizing member is a reflective linear polarizing member, and is arranged in the optical path between the self-luminous light-emitting element and the lens in the order of the phase difference member, the reflective polarizing member, and the absorbing polarizing member, from the self-luminous light-emitting element side.

6. The display system according to claim 1, wherein the reflective polarizing member is a reflective circular polarizing member, and is arranged in the optical path between the self-emitting light-emitting element and the lens in the order of the reflective polarizing member, the phase difference member, and the absorbing polarizing member, from the self-emitting light-emitting element side.

7. A near-eye display device comprising the display system according to any one of claims 1 to 6.

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